Patent application number | Description | Published |
20080196418 | Method and Control for Preventing Flooded Starts in a Heat Pump - A heat pump is provided with an improvement while switching from heating/cooling mode to a defrost mode. Prior to initiation of a defrost mode, an electronic expansion device is moved to an open position such that refrigerant can migrate between the indoor-outdoor heat exchangers. When the operation of the defrost cycle is initiated, there is a lower likelihood and severity of flooded starts, as the refrigerant, under existing pressure differential at system shutdown, will move to the heat exchanger that will be downstream of the compressor in the defrost mode. Thus, no flooded start will occur on the subsequent compressor start-up. After completion of the defrost cycle, the electronic expansion device is again opened prior to return to operation in the conventional heating/cooling mode. In case subsequent starts are in an identical mode of operation, the electronic expansion valve is kept closed during shutdown to minimize cyclic performance losses. | 08-21-2008 |
20080196426 | System Reheat Control by Pulse Width Modulation - A refrigerant system is provided with a reheat circuit. A pulse width modulation control is provided to achieve variable reheat capacity and thus to satisfy a wide spectrum of temperature and humidity levels in an environment conditioned by a refrigerant system. The pulse width modulation signal provided for the reheat flow control device achieves incremental amounts of reheat while avoiding temperature and humidity variations in the conditioned space. | 08-21-2008 |
20080196445 | Variable Speed Compressor Motor Control for Low Speed Operation - A variable speed drive is provided for a compressor in a refrigerant system. When a low load situation has been determined by the refrigerant system controls, the variable speed drive moves the compressor to a lower speed mode of operation. In this case, if a speed is so low that it cannot ensure adequate oil lubrication of the compressor elements, then the motor speed is periodically increased to a level that will ensure proper lubrication. In this manner, a variable speed drive compressor can be operated at an extremely low speed to precisely match load demand on a refrigerant system. The invention can be extended beyond refrigerant system applications and to any oil-lubricated compressors whose lubrication is speed dependant. | 08-21-2008 |
20080202155 | Closed-Loop Dehumidification Circuit For Refrigerant System - A closed-loop reheat circuit decoupled from a main refrigerant circuit is provided as part of a refrigerant system. In the closed-loop reheat circuit refrigerant is flown through an auxiliary heat exchanger, at which it transfers heat to refrigerant in the main circuit, increasing its cooling and dehumidification potential prior to entering an evaporator. The closed-loop circuit also includes a reheat heat exchanger that is placed in the path of at least a portion of airflow having passed over an evaporator. The reheat heat exchanger reheats air supplied to a conditioned space to a desired temperature after sufficient amount of moisture has been removed from the air in the evaporator to provide a comfortable humidity level. By utilizing the closed-loop reheat circuit, a control for the overall refrigerant system becomes less complex and more flexible, and the refrigerant system operation turns out to be more reliable and satisfying a variety of environmental conditions and potential applications. Various features and options of the decoupled reheat circuit concept are also disclosed. | 08-28-2008 |
20080223057 | Refrigerant System with Pulse Width Modulated Components and Variable Speed Compressor - A variable speed drive is provided for operating a compressor motor in a refrigerant system. When a low load situation has been determined by the refrigerant system controls, the variable speed drive operates the compressor motor at lower speed mode of operation. Further, the operation of the variable speed drive is combined with a pulse width modulation control of different system components. In particular, at least one valve or compressor can be can be rapidly cycled by the control to regulate amount of refrigerant passing through the valve or compressor. Example valves would include a shut-off valve for an economizer cycle, an unloader valve, or a suction modulation valve. | 09-18-2008 |
20080229762 | Multi-Circuit Refrigerant System Using Distinct Refrigerants - A multi-circuit refrigerant system includes a plurality of circuits that are provided with distinct refrigerants. A control selectively matches a sensed environmental space conditioning challenge to selectively engage the plurality of circuits. | 09-25-2008 |
20080229764 | Refrigerant Dehumidification System with Variable Condenser Unloading - A condenser in a refrigerant system is provided with a plurality of refrigerant circuits, with at least one of the plurality of circuits being equipped with a shut off device. A reheat coil is also incorporated into the refrigerant system to provide enhanced dehumidification functionality. By selectively shutting off at least one of the active refrigerant circuits in the condenser, the amount of heat rejected by the condenser as well as by the reheat coil can be controlled shifting the heat load between the condenser and reheat coil. In this manner, and in combination with operation of the reheat cycle, incremental dehumidification and cooling/heating can be provided and humidity and temperature can be precisely controlled. | 09-25-2008 |
20080250801 | Pulse Width Modulation System with Pressure Regulating Valve - A pulse width modulation control is provided for a suction valve on a suction line, delivering refrigerant into a housing shell of a compressor. When the suction valve is closed, the pressure within the housing shell can become very low. Thus, a pressure regulator valve is included within the refrigerant system to selectively deliver a limited amount of refrigerant into the housing shell when the suction valve is closed. The delivery of this limited amount of refrigerant ensures that a specified pressure is maintained within the housing shell to achieve the most efficient operation while at the same time preventing problems associated with damage to electrical terminals, motor overheating and excessive discharge temperature. | 10-16-2008 |
20080250812 | Multi-Circuit Refrigerant System Utilizing Pulse Width Modulation Techniques - A multi-circuit refrigerant system incorporates at least one component provided with a pulse width modulation control. This component can be controlled to adjust the capacity provided by the circuit incorporating the component. In this manner, the pulse width modulation component can be controlled to exactly tailor the capacity of that circuit to provide a total desired combined cooling capacity of the multiple circuits within the multi-circuit system configurations. In one embodiment, only one circuit in a multi-circuit refrigerant system incorporates a pulse width modulation controlled component. In another embodiment, a plurality of circuits are provided with pulse width modulation controlled components. | 10-16-2008 |
20080256961 | Economized Refrigerant System with Vapor Injection at Low Pressure - A refrigerant system with an economizer cycle incorporates a time dependant vapor injection scheme to reduce losses and enhance performance. The benefits of such an approach are particularly pronounced at low pressure ratios typical of air conditioning applications. The injection of refrigerant occurs during a limited time interval and at a particular point of time into a compression cycle. The vapor injection preferably occurs when the compression chamber are sealed (or about to be sealed off) from a suction port and continues until refrigerant pressure in the compression chambers is equal (or about to be equal) to the pressure at the injection line. This communication time constitutes about 35% of time of one revolution. In one embodiment, such time dependence of refrigerant vapor injection is provided by a specific compressor design. In another embodiment, a fast-acting solenoid valve is placed at the vicinity of the injection port to control the initiation and duration of the injection process. The benefits for an unloading scheme are disclosed as well. | 10-23-2008 |
20080256975 | Vapor Compression System With Condensate Intercooling Between Compression Stages - A refrigerant vapor compression system includes a first compression device and a second compression device disposed in a refrigerant circuit in series relationship with respect to refrigerant flow and an intercooler adapted to cool the refrigerant passing from the first compression device to the second compression. An evaporator is provided in the refrigerant circuit wherein the refrigerant accepts heat from a moisture bearing gas such as air. Condensate formed of moisture condensing out of the gas is collected and supplied to the intercooler for cooling the refrigerant flowing from the first compression device to the second compression device. | 10-23-2008 |
20080260541 | Induction Motor Control - The operation of an AC induction motor | 10-23-2008 |
20080276637 | Speed Control of Multiple Components in Refrigerant Systems - Variable speed drives are utilized in refrigerant systems to operate motors of the system components at varying speeds, typically for the purposes of capacity adjustment, efficiency enhancement, reliability improvement or power consumption limitation. However, variable speed controls are expensive. The present invention offers flexibility to utilize a variable speed drive to provide variable speed functionality between compressor and fans (or other rotating components having electric motors) within a refrigerant system depending on operational and environmental conditions and external load demands. The switching device switches the variable speed drive between component motors as indicated by a control for the refrigerant system. | 11-13-2008 |
20080296005 | Parallel Flow Heat Exchanger For Heat Pump Applications - A parallel flow heat exchanger system ( | 12-04-2008 |
20080307813 | Variable Capacity Multiple Circuit Air Conditioning System - A refrigerant vapor compression system for conditioning air within a climate controlled space has multiple refrigerant circuits including at least one refrigerant circuit having a fixed capacity and at least one refrigerant circuit having a variable capacity. Each refrigerant circuit includes a compressor, a condenser, an expansion device and an evaporator connected in refrigerant circulation flow communication. The compressor associated with each fixed capacity refrigerant circuit is a fixed speed compressor and the compressor associated with each variable capacity refrigerant circuit is a variable speed compressor. A controller is provided for controlling the speed of the variable speed compressor to adjust the refrigeration capacity of the variable capacity refrigerant circuit and thereby adjust the overall capacity of the system to match the cooling demands. | 12-18-2008 |
20080314055 | Refrigerant System Unloading By-Pass Into Evaporator Inlet - A refrigerant system has at least one unloader valve selectively communicating refrigerant between the compressor compression chambers and a point upstream of the evaporator. When the compressor is run in unloaded mode, partially compressed refrigerant is returned to a point upstream of the evaporator. In an unloaded mode, a higher refrigerant mass flow rate passes through the evaporator, as compared to prior art where the by-passed refrigerant was returned downstream of the evaporator. This increases system efficiency by more effectively returning oil which otherwise might be left in the evaporator back to the compressor. Also, the amount of refrigerant superheat entering the compressor in unloaded operation is reduced as compared to the prior art compressor systems, wherein the by-passed refrigerant is returned directly to the compressor suction line. Reduced refrigerant superheat increases system efficiency, improves motor performance and reduces compressor discharge temperature. Also, by moving the unloader line further away from the compressor, the compressor replacement is simplified as there is no connecting unloader line directly in front of the compressor. | 12-25-2008 |
20080314057 | Refrigerant System With Variable Speed Scroll Compressor and Economizer Circuit - A scroll compressor system having a variable speed drive is utilized. By providing the economizer and/or bypass functions along with the variable speed drive, precise capacity adjustment between the discrete steps is achieved to exactly match load demands at a wide spectrum of operating conditions. | 12-25-2008 |
20080314063 | Combined Muffler and Oil Separator for Refrigerant System - A refrigerant system ( | 12-25-2008 |
20090012651 | Including Energy Price in Optimizing Refrigerant System Operation - An HVAC & R system controller is provided with time pricing information for electricity and/or natural gas. This pricing information is utilized to determine the most efficient system configuration and operation schedule to achieve desired conditions in an indoor environment. As an example, if electricity prices are high, then the controller might rely on a natural gas powered furnace, rather than on the higher-electricity consuming heat pump. In another example, thermal storage media can be charged during off-peak hours when cost of electricity is low and release its thermal potential during high demand periods. | 01-08-2009 |
20090013701 | REFRIGERANT SYSTEM WITH CONTROL TO ADDRESS FLOODED COMPRESSOR OPERATION - A suction modulation valve is throttled when conditions in a refrigerant system indicate that an undesirable amount of liquid refrigerant might otherwise be delivered to the compressor. As an example, the throttling would occur at start-up, among other conditions. Throttling the suction modulation valve reduces the amount of refrigerant reaching the compressor and thus ensures that any liquid refrigerant would be likely “boiled off” before raising any problems in the compressor. Other control steps can also be performed to alleviate flooded compressor operation with liquid refrigerant. Such steps, for example, can consist of: actuating heaters, discharge valve throttling, by-passing refrigerant from intermediate compression point back to suction, controlling the speed of the condenser fan can be performed independently or in combination including the suction modulation valve throttling. | 01-15-2009 |
20090050703 | HVAC&R System Control Utilizing On-Line Weather Forecasts - A controller for an HVAC & R system is provided with the Internet connection to weather forecast information. The weather forecast information is utilized by the controller to take proactive steps in system operation and control. As an example, should the weather forecast information indicate that temperatures will be rising dramatically the next day, the controller may take the proactive step of increasing cooling in the conditioned space during the nighttime. In this manner, when the ambient temperature begins to rise the next day, the cooling load on the HVAC & R system components will be lower. Analogous proactive steps can be taken regarding humidity and fresh air circulation rate within the conditioned space. The present invention not only provides more prompt tailoring of the conditions within an environment to desired conditions, but also does so in a more efficient and less expensive manner | 02-26-2009 |
20090113900 | METHODS AND APPARATUS FOR OPERATING AIR CONDITIONING SYSTEMS WITH AN ECONOMIZER CYCLE - Methods and apparatus are provided for enhancing the performance of rooftop air conditioning systems by operating such systems with an economizer cycle and utilizing a blend incorporating R32 and R125 refrigerants as a working medium, wherein such benefits are related to at least the performance (e.g. capacity and/or the energy efficiency ratio) of the rooftop air conditioning system operating at various environments (e.g. temperatures at and above 95° F.). | 05-07-2009 |
20090120111 | Remote Diagnostics and Prognostics for Refrigerant Systems - There is provided a refrigerant system including a plurality of components for regulating operational parameters of the refrigerant system, at least one transducer connected to the refrigerant system for monitoring the operational parameters of the refrigerant system, and a controller. The controller is remotely connected to the at least one transducer and to at least one component of the plurality of components for at least periodically receiving parameter information from the at least one transducer to monitor the operational parameters and determine, based on variations in at least one parameter of the operational parameters, whether a condition exists in the refrigerant system that requires corrective action. The corrective action may include moving the refrigerant system to a lighter mode of operation by unloading or even shutting down some of the refrigerant system components. There is also provided a method for monitoring the refrigerant system. | 05-14-2009 |
20090125150 | System and Method for Control of Heat Pump Operation - There is provided a space heating system ( | 05-14-2009 |
20090139246 | REMOTE SOFTWARE LOADING FOR REFRIGERANT SYSTEM - A refrigerant system control software upgrades are remotely downloaded over information carrying media. The software upgrades can be timed to occur when the Internet traffic is low. Once the upgrade has been received, a verification test may be performed for the refrigerant system components affected by the software upgrade. The test is monitored, and the results are sent back to the remote location such that the remote location can ensure the software upgrade was successful. | 06-04-2009 |
20090165472 | SYSTEM PERFORMANCE CORRECTION BY MODIFYING REFRIGERANT COMPOSITION IN A REFRIGERANT SYSTEM - An adequate operation and performance of a refrigerant system includes the steps of adding a refrigerant that is different from the original refrigerant, into the refrigerant system should any operational problems be observed during operation of the refrigerant system. As an example, should the refrigerant system be cycling frequently, a lower pressure refrigerant may be added or replace, partially or fully, the refrigerant the system being initially charged with. By making this change, the present invention can, for example, lower the provided system capacity, and hence reduce the amount of cycling. Additionally, conditioned space comfort and system reliability would be improved. Further, changes over time, such as the degradation of the heat exchanger performance, and their negative effect on system operation can be alleviated by such a refrigerant substitution. | 07-02-2009 |
20090205349 | SUCTION VALVE PULSE WIDTH MODULATION CONTROL BASED ON COMPRESSOR TEMPERATURE - A refrigerant system is provided with a pulse width modulation valve. A compressor temperature is monitored to prevent potential reliability problems and compressor failures due to an excessive temperature inside the compressor A control changes the pulse width modulation valve duty cycle rate to maintain temperature within specified limits, while achieving the desired capacity, and complying with design requirements of a conditioned environment, without compromising refrigerant system reliability. As the compressor temperature increases, the pulse width modulation valve duty cycle time is adjusted to ensure that adequate amount of refrigerant is circulated through the compressor to cool the compressor internal components. | 08-20-2009 |
20090235673 | DETECTION OF REFRIGERANT RELEASE IN CO2 REFRIGERANT SYSTEMS - A refrigerant system utilizes environmentally friendly natural refrigerant such as carbon dioxide. A pressure relief mechanism such as pressure relief valve is incorporated into the refrigerant system design to allow for at least some amount of refrigerant to be released to atmosphere to provide safe operation or comply with agency regulations if pressure within the refrigerant system exceeds a certain limit. This release can occur during refrigerant system storage, transportation or operation. A detection device such as an electrical circuit is included into the refrigerant system design to provide an indication that pressure relief valve has opened, such that the determination can be made by a refrigerant system control or an operator whether the refrigerant system needs to be recharged and whether it can continue its normal operation, narrow its operational envelope or shut down until the refrigerant charge can be restored. | 09-24-2009 |
20090235678 | OPERATION AND CONTROL OF TANDEM COMPRESSORS AND REHEAT FUNCTION - A refrigerant system control operates tandem compressors. If one of the monitored system conditions does not change as each of the tandem compressors or associated components is brought on line, then a determination is made that the respective component is malfunctioning. A refrigerant system can also be additionally equipped with other functions and components, such as variable speed drive, economizer circuit, unloader bypass, and reheat circuit. In case of a reheat circuit, the system can consist of single or multiple compressors. The control algorithm can also be updated such that that particular malfunctioning component is eliminated from the operational sequence. | 09-24-2009 |
20090255278 | Refrigerant System With Variable Speed Drive - A refrigerant system ( | 10-15-2009 |
20090255281 | Diagnostic Method for Proper Refrigerant Valve Operation - There is provided a refrigerant system | 10-15-2009 |
20090288432 | TANDEM COMPRESSORS WITH PULSE WIDTH MODULATION SUCTION VALVE - A refrigerant system is provided with tandem compressors. A tandem compressor arrangement includes at least two compressors operating in parallel and having at least one common manifold. A control may operate the compressors either simultaneously, or in some predetermined sequence to provide control over refrigerant system capacity. At least one of the tandem compressors is provided with a pulse width modulation control on a suction line. In this manner, the amount of refrigerant, compressed by the compressor, can be precisely controlled to exactly meet thermal load demands in the conditioned space. | 11-26-2009 |
20090293515 | ECONOMIZED REFRIGERANT VAPOR COMPRESSION SYSTEM FOR WATER HEATING - An economized refrigerant vapor compression system ( | 12-03-2009 |
20090308086 | REFRIGERANT SYSTEM WITH MULTI-SPEED PULSE WIDTH MODULATED COMPRESSOR - A refrigerant system is provided with a compressor having a motor that is operable at least at two distinct speeds. The pulse width modulation control is provided to cycle a compressor motor operation between its at least two speeds at a specific rate to exactly match thermal load demands in a conditioned space. The present invention reduces cycling and other efficiency losses as have been experienced in the prior art, as well as minimizes cost and may improve reliability. Also, the present invention can be utilized in conjunction with other known unloading techniques. | 12-17-2009 |
20090311119 | Screw Compressor Capacity Control - A screw compressor has a housing ( | 12-17-2009 |
20090320506 | REFRIGERANT SYSTEM WITH EXPANSION DEVICE BYPASS - A refrigerant system is provided with an expansion device that may be a thermostatic expansion device or an electronic expansion device. A bypass line selectively allows a portion of refrigerant to bypass the expansion device and to flow through a fixed restriction expansion device such as an orifice positioned in parallel configuration with the main expansion device. A valve selectively enables or blocks refrigerant flow through this bypass line depending on the volume of refrigerant required to circulate through the refrigerant system as defined by environmental conditions and a mode of operation. The valve can be a simple shutoff valve or a three-way valve selectively allowing or blocking refrigerant flow through a particular refrigerant line or lines. In one embodiment, the expansion device is the main expansion device for the refrigerant system. In the other embodiment, the expansion device is a vapor injection expansion device for expanding refrigerant for performing an economizer function. The present invention allows the use of a smaller expansion device, which can be more precisely controlled, while still allowing the accommodation of higher refrigerant mass flow when necessary. | 12-31-2009 |
20100000238 | HEATING, VENTILATION, AIR CONDITIONING AND REFRIGERATION SYSTEM WITH MULTI-ZONE MONITORING AND DIAGNOSTICS - A multi-zone HVAC&R system has its control programmed to provide diagnostic testing of air handling components and refrigerant components associated with each climate controlled zone in sequence. The control changes the original position of the corresponding component and a resultant change in a relevant operational parameter is sensed. If the actual change is outside of the tolerance band associated with the expected change, then the determination is made that the component under consideration is malfunctioning. The periodicity of a diagnostic procedure for a particular component is typically defined by its criticality and reliability level. If the change in the corresponding operation parameter is recorded and stored in the database, the component degradation can be observed over time and a prognostic prediction can be made when a particular component requires preventive maintenance or replacement. | 01-07-2010 |
20100000239 | PULSE WIDTH MODULATION CONTROL FOR HEAT PUMP FAN TO ELIMINATE COLD BLOW - A heat pump refrigerant system is provided with a pulse width modulation control for a fan moving air over the indoor heat exchanger. When it is determined that there is insufficient heat rejected by the indoor heat exchanger to heat the volume of air being delivered by the fan into the conditioned environment, the volume of air supplied to the conditioned environment is reduced by utilizing one of pulse width modulation techniques to cycle the indoor fan motor to reduce the average volume of supplied air. Therefore, a precise control over the temperature of air delivered to the conditioned space is achieved, temperature of the delivered air is increased to the target value, and so-called “cold blow” conditions are avoided. | 01-07-2010 |
20100003151 | REFRIGERANT SYSTEM WITH MULTI-SPEED SCROLL COMPRESSOR AND ECONOMIZER CIRCUIT - A scroll compressor is provided with a multiple-speed motor. A control selects a speed for operating the motor, along with selecting between several available options for the system capacity adjustment to meet external load demands in a most efficient and reliable manner. The disclosed embodiment includes an economizer circuit, an unloader function, and an optional suction modulation valve. By utilizing each of these features in combination with the multi-speed motor for the compressor, the present invention is better able to tailor provided capacity to desired capacity. | 01-07-2010 |
20100011787 | PREVENTION OF REFRIGERANT SOLIDIFICATION - A refrigerant system may utilize CO | 01-21-2010 |
20100011788 | OFF-SEASON START-UPS TO IMPROVE RELIABILITY OF REFRIGERANT SYSTEM - A vapor compression system includes a timer and a controller for periodically starting up the system during the off-season periods (primarily non-cooling months) in which the system would normally be shut down. This provides periodic lubrication to the compressor components and prevents severe flooded starts due to excessive accumulation of refrigerant in the compressor (compressor oil sump in particular) and other system components. Provision is also made to sequentially turn on and off system components such as the compressor, the evaporator fan and the condenser fan to enhance the system operation. The timing sequences are provided for the time intervals between the startups, as well as the off-season operation cycle times. | 01-21-2010 |
20100011792 | REFRIGERANT SYSTEM WITH PULSE WIDTH MODULATION CONTROL IN COMBINATION WITH EXPANSION DEVICE CONTROL - A refrigerant system is provided with pulse width modulation control to adjust the amount of refrigerant compressed by a compressor. In one embodiment, a pulse width modulation control controls a suction modulation valve cycled between open and closed positions. In a second embodiment, the compressor itself is cycled between a position at which it compresses refrigerant and a position at which the compression elements are disengaged. In either embodiment, the control also cycles the expansion device in concert with cycling the pulse width modulation valve or the compressor. In this manner, pressure fluctuations in the refrigerant system do not exceed desirable levels. Typical cycle time for pulse width modulation control is between 5 and 30 seconds, and typical offset (delay) time for an expansion device may be between 0 and 3 seconds. | 01-21-2010 |
20100012305 | MULTI-CHANNEL HEAT EXCHANGER WITH IMPROVED CONDENSATE DRAINAGE - A heat exchanger includes a first generally vertical header and a second generally vertical header and a generally vertical array of a plurality of generally flat heat exchange tubes extending in a horizontal direction therebetween. Each heat exchange tube has a plurality of channels extending longitudinally in parallel relationship from its inlet end to its outlet end, each channel defining a discrete refrigerant flow path. A plurality of fins extends between parallel-arrayed tubes. To facilitate drainage of the collected condensate from the external surfaces of the flat heat exchange tubes, the tubes are aligned at a slight angle with respect to the horizontal so that the trailing edge of each tube is positioned lower than the leading edge of each tube. To further assist in the condensate drainage, the trailing edge of each of the fins may extend beyond the trailing edge of the associated heat transfer tubes and a lower extension lip may extend downwardly from the trailing edge of each of the fins. | 01-21-2010 |
20100012307 | MULTI-CHANNEL FLAT TUBE EVAPORATOR WITH IMPROVED CONDENSATE DRAINAGE - A heat exchange tube includes a tubular member having a flattened cross-section and extending along a longitudinal axis, and a longitudinally extending condensate drain channel formed in an upper wall of the flattened tubular member. A heat exchanger includes a first and a second spaced apart and generally vertical longitudinally extending headers, a plurality of heat exchange tubes disposed in parallel, spaced relationship in a generally vertical array and extending longitudinally between the first header and the second header, and a condensate drain extending longitudinally along, the upper wall of at least one of the plurality of flattened heat exchange tubes. The condensate drain may comprise a longitudinally extending condensate drain channel formed in an upper wall of said flattened tubular member, and/or a series of condensate drain portals formed in the heat transfer fins in a base portion bounding to the upper external surface of at least one heat exchange tube. The condensate drain portals of neighboring heat transfer fins are aligned longitudinally to provide a series of longitudinally aligned condensate drain portals along the upper external surfaces of the heat exchange tubes. | 01-21-2010 |
20100024452 | MICRO-CHANNEL EVAPORATOR WITH FROST DETECTION AND CONTROL - A refrigerant vapor compression system includes an evaporator having a plurality of longitudinally extending, flattened heat exchange tubes disposed in parallel, spaced relationship. Each of the heat exchange tubes has a flattened cross-section and defining a plurality of discrete, longitudinally extending refrigerant flow passages. One or more frost detection sensor(s) is/are installed in operative association with the evaporator for detecting a presence of frost/ice formation on at one of the flattened heat exchange tubes and associated heat transfer fins. A defrost system is provided and operatively associated with the evaporator heat exchanger A controller, operatively coupled to the frost detection sensor(s) and to the defrost system, selectively activates the defrost system to initiate a defrost cycle of the evaporator in response to the signal indicative of the presence of frost formation on the flattened heat exchange tubes and heat transfer fins. | 02-04-2010 |
20100024470 | REFRIGERANT INJECTION ABOVE CRITICAL POINT IN A TRANSCRITICAL REFRIGERANT SYSTEM - A refrigerant system operates in a transcritical regime. An economizer circuit is incorporated into the refrigerant system, and includes an economizer injection line for refrigerant injection above the critical point. In one of the disclosed embodiments, the refrigerant utilized is CO | 02-04-2010 |
20100031677 | REFRIGERANT SYSTEM WITH VARIABLE CAPACITY EXPANDER - A refrigerant system incorporates a variable capacity expander. A bypass line selectively bypasses at least a portion of the refrigerant approaching the expander to the intermediate expansion point within the expander. In this manner, the refrigerant expansion process is controlled more efficiently than in the prior art. | 02-11-2010 |
20100032133 | HEAT PUMP WITH INTERCOOLER - A heat pump refrigerant system is provided with at least two sequential stages of compression. An intercooler is positioned intermediate the two stages. The refrigerant flowing through the intercooler. is cooled by a secondary fluid such as ambient air. The intercooler is positioned to be in a path of air flow passing over an outdoor heat exchanger, and preferably upstream of the outdoor heat exchanger, in relation to this air flow. Benefits with regard to efficiency and capacity are achieved due to proposed system configuration in both heating and cooling modes of operation, while no additional circuitry or components are required to provide the intercooler function for the heat pump refrigerant system. This invention is particularly important for the CO | 02-11-2010 |
20100043468 | PULSE WIDTH MODULATION WITH DISCHARGE TO SUCTION BYPASS - A pulse width modulation control is provided for a suction valve located on a suction line. When the flow rate through a refrigerant system needs to be reduced, the suction valve is rapidly cycled from an open position to a closed position. A bypass line connecting compressor discharge to compressor suction with a bypass valve and a discharge valve positioned on the discharge side of the compressor are also provided. When the control closes the suction valve, it also closes the discharge valve to prevent the refrigerant to backflow into the bypass line, and, at the same time, the control opens the bypass valve. Opening of the bypass valve reduces discharge pressure, leading to reduction in compressor power consumption and subsequent operating efficiency gain. | 02-25-2010 |
20100043475 | CO2 REFRIGERANT SYSTEM WITH BOOSTER CIRCUIT - A refrigerant system, which utilizes CO | 02-25-2010 |
20100051126 | TADEM COMPRESSORS WITH COMMON INTERMEDIATE PORT - A compressor assembly includes at least two tandem compressors. Tandem compressors have at least one common suction manifold, communicating a source of working fluid to be compressed by each of at least two compressors, and at least one common discharge manifold communicating a compressed fluid downstream for further use. A common intermediate pressure manifold communicates with intermediate pressure ports in at least two compressors. The intermediate manifold may communicate fluid to or out of the at least two compressors. There is normally no direct communication between suction and discharge manifolds. | 03-04-2010 |
20100058781 | REFRIGERANT SYSTEM WITH ECONOMIZER, INTERCOOLER AND MULTI-STAGE COMPRESSOR - A refrigerant system is provided with a multi-stage compression system. An intercooler is positioned between at least two compression stages to cool a refrigerant, by heat transfer interaction with a secondary fluid, after it has been compressed in the lower compression stages to some intermediate pressure. The intercooler enhances refrigerant system performance, improves compressor reliability, and extends operational envelope. Further, at least one economizer circuit is incorporated into the refrigerant system that returns the economized refrigerant flow at the location between at least two compression stages. | 03-11-2010 |
20100058783 | INJECTION OF REFRIGERANT IN SYSTEM WITH EXPANDER - A refrigerant system incorporates an expander. At least a portion of refrigerant bypasses an evaporator and is injected into the compression process to cool main refrigerant vapor flow and compressor elements. In disclosed embodiments, the injected refrigerant may be partially expanded in the expander and routed either into the compressor suction or to an intermediate point in the compression process. A valve may control the amount of the injected refrigerant to achieve desired operational characteristics for the refrigerant system. | 03-11-2010 |
20100058799 | SUCTION VALVE PULSE WIDTH MODULATION CONTROL BASED ON EVAPORATOR OR CONDENSER PRESSURE - A refrigerant system is provided with a suction pulse width modulation valve, and a pulse width modulation control for controlling this valve. System pressures, such as the pressure on the evaporator and the condenser are monitored. The measured system pressures are maintained within a band of acceptable lower and upper limits. As the pulse width modulation control cycles the valve, the refrigerant pressures in the evaporator and the condenser tend to fluctuate. The control ensures those fluctuations are within the limits by controlling the duty cycle of the valve. | 03-11-2010 |
20100064702 | COMBINED OPERATION AND CONTROL OF SUCTION MODULATION AND PULSE WIDTH MODULATION VALVES - A refrigerant system is provided with a pulse width modulation suction valve and a second valve on a line that bypasses the pulse width modulation suction valve. This second valve has a variable opening. In this manner, the pressure within the compressor shell is maintained at the lowest possible level regardless of the system operating conditions, when the pulse width modulation suction valve is cycled to a closed position. Further, the second valve can continue providing capacity control, should the pulse width modulation suction valve fail. | 03-18-2010 |
20100068084 | MODULAR COMPRESSOR-VALVE DESIGN FOR REFRIGERANT SYSTEM - A compressor-valve modular design provides manufacturing simplicity, reduces applied cost, and improves quality and reliability of a refrigerant system. In this design, a valve is preferably an electronically controlled valve having a control member that controls the flow of a fluid through the valve. A discharge valve, a stepper motor modulation valve, an economizer vapor injection valve, a liquid injection valve or any combination of thereof are the examples of the valves within the compressor-valve subassembly. | 03-18-2010 |
20100071391 | CO2 REFRIGERANT SYSTEM WITH TANDEM COMPRESSORS, EXPANDER AND ECONOMIZER - A refrigerant system utilizes an expander that provides a more efficient expansion process and recovers at least a portion of energy from this expansion process. At least a portion of refrigerant that has been at least partially expanded in the expander is tapped and passed through an economizer heat exchanger. In the economizer heat exchanger, the tapped refrigerant cools a main circuit refrigerant increasing its thermodynamic potential. Further, a compression section is provided with at least two compressors operating in tandem and allowing for multiple stages of unloading. By selectively utilizing one or more of the tandem compressors, the economizer cycle, and the expander, the refrigerant system can achieve very efficient operation and provide enhanced control flexibility, in particular, for the CO | 03-25-2010 |
20100071407 | REFRIGERANT SYSTEM WITH INTERCOOLER UTILIZED FOR REHEAT FUNCTION - A refrigerant system is provided with at least two stages of compression connected in series. An intercooler is positioned intermediate the two stages and is cooled by an indoor air stream. The intercooler is positioned to be in a path of air flow passing over an indoor heat exchanger, and preferably downstream of the indoor heat exchanger, in relation to this airflow. The intercooler cools the refrigerant flowing between the two compression stages as well as provides the reheat function. Benefits with regard to system performance (efficiency, capacity and reliability) are achieved with no additional circuitry or components required to provide the intercooler and reheat functions. This invention is particularly important for the CO | 03-25-2010 |
20100077777 | ECONOMIZED REFRIGERATION CYCLE WITH EXPANDER - A refrigerant vapor compression system includes a compression device, a heat rejecting heat exchanger, an economizer heat exchanger, an expander and an evaporator disposed in a refrigerant circuit. An evaporator bypass line is provided for passing a portion of the refrigerant flow from the main refrigerant circuit after having traversed a first pass of the economizer heat exchanger through the expander to partially expand it to an intermediate pressure and thence through a second pass of the economizer heat exchanger and into an intermediate pressure stage of the compression device. An economizer bypass line is also provided for passing a portion of the refrigerant from the main refrigerant circuit after having traversed the heat rejecting heat exchanger through a restrictor type expansion device and thence into the evaporator bypass line as liquid refrigerant or a mix of liquid and vapor refrigerant for injection into an intermediate pressure stage of the compression device. Both economizer and injection flows are mixed together prior to entering an intermediate compression point, when an economizer circuit is active. The invention allows for enhanced system performance and advanced discharge temperature control. | 04-01-2010 |
20100083677 | ECONOMIZED REFRIGERANT SYSTEM UTILIZING EXPANDER WITH INTERMEDIATE PRESSURE PORT - A refrigerant system utilizes an expander, where at least partially expanded refrigerant portion is tapped at the intermediate expansion point and passed through an economizer heat exchanger. In the economizer heat exchanger, the tapped refrigerant further cools refrigerant in a main liquid line. The present invention eliminates the need for a separate dedicated economizer circuit expansion throttling device, by utilizing a single expander to provide this expansion function. This invention also allows for the recovery of the expansion work, otherwise lost in the economizer expansion throttling device. System capacity and efficiency are improved by providing additional thermal potential for the refrigerant expanded (partially or fully) in the expander during more efficient isentropic process. In various embodiments, there may be more than a single economizer circuit, with each of said economizer circuits receiving the tapped refrigerant portions from the expander at different intermediate expansion points. | 04-08-2010 |
20100083678 | REFRIGERANT SYSTEM WITH EXPANDER SPEED CONTROL - A refrigerant system utilizes an expander to expand refrigerant and to drive or assist in driving an associated compressor. By varying the compressor load, the speed of the expander can be adjusted to achieve the desired thermodynamic characteristics of the expanding refrigerant and enhance expander operation. | 04-08-2010 |
20100092306 | COMPRESSOR REVERSE ROTATION OF VARIABLE DURATION ON START-UP - In a method of operating a compressor at startup, the compressor is rotated in reverse for a brief period of time. The compressor is of a type that does not compress liquid when rotated in reverse. The purpose is to boil off the liquid refrigerant from the oil by heating and agitating the mixture of oil and refrigerant in the oil sump. This results in a much more benign forward start as less refrigerant is drawn into the compressor pump and the amount of oil pumped out of the compressor on start up is minimized. Also, the viscosity of oil is increased and lubrication of the bearings is improved. After a short period of time reverse rotation is stopped and the compressor can start rotating in the forward direction. The short period of time of reverse rotation is varied based upon system conditions. In one embodiment, the variation can occur by reducing the reverse run time as ambient temperature increases. In another embodiment, electrical conditions such as incoming voltage and/or a ratio of voltage to frequency can be utilized to change the reverse run time. | 04-15-2010 |
20100095688 | REFRIGERANT DISTRIBUTION IMPROVEMENT IN PARALLELL FLOW HEAT EXCHANGER MANIFOLDS - A method and apparatus are presented to ensure adequate distribution of a two-phase refrigerant flowing through a plurality of heat transfer tubes of a parallel flow heat exchanger in a generally parallel manner. In several embodiments of this invention, predominantly single-phase refrigerant (liquid for condensers and vapor for evaporators) is tapped and delivered downstream to a location where a predominantly single-phase refrigerant phase is already present, bypassing at least some of the heat transfer tubes. In this manner, the remaining single-phase refrigerant (vapor for condensers and liquid for evaporators) flowing through the heat exchanger core is uniformly distributed amongst a plurality of heat transfer tubes in the next downstream pass. | 04-22-2010 |
20100095693 | SUCTION MODULATION VALVE FOR REFRIGERANT SYSTEM WITH ADJUSTABLE OPENING FOR PULSE WIDTH MODULATION CONTROL - A pulse width modulation control is provided for a suction modulation valve in a refrigerant system. An intentional small “leakage” path is maintained through the suction modulation valve to ensure that the pressure inside the compressor shell does not decrease below a safe reliability threshold but, at the same time, does not exceed a certain value, which would cause the refrigerant system to operate inefficiently, when the pulse width modulation control has moved the suction modulation valve to a closed position. The size of this minimum “leakage” path is continuously adjusted to ensure that the optimum pressure inside the compressor shell is maintained regardless of the evaporator pressure and other operating conditions. | 04-22-2010 |
20100101247 | ADJUSTMENT OF COMPRESSOR OPERATING LIMITS - A refrigerant system includes a compressor that has safe operating limits that are also built into a refrigerant system control to protect the compressor. Under certain conditions, these safe operational limits may be changed to allow the compressor to operate beyond the safety limits at least for a period of time. | 04-29-2010 |
20100101248 | Refrigerant System and Control Method - A refrigerant system is configured to alternatingly run in an economized mode and a standard mode. A control system shifts the refrigerant system between the economized mode and standard mode responsive to a determined efficiency reflecting a combination of at least two of: compressor isentropic efficiency; condenser efficiency; evaporator efficiency; efficiency of hardware mechanically powering the compressor; and a mode-associated cycling efficiency. In a bypass mode, a bypass refrigerant flow from an intermediate port may return to the suction port. Shifting into the bypass mode may be similarly controlled based upon the determined efficiency. | 04-29-2010 |
20100107675 | HEAT EXCHANGER WITH IMPROVED CONDENSATE REMOVAL - A heat exchanger includes an arrangement of refrigerant conveying heat exchange tubes and associated heat transfer fins and has an airflow inlet and an airflow outlet. A plurality of inlet guide vanes is disposed slightly upstream of the airflow inlet to the heat exchange tube arrangement so as to route incoming airflow through the heat exchange tube arrangement along a desired direction, in relation to the heat exchange tubes and associated fins, so as to improve drainage of accumulated condensate from the external surfaces of the heat exchange tubes and to enhance shedding of condensate from the surfaces of the heat transfer fins. Also, a plurality of outlet guide vanes can be disposed slightly downstream of the airflow outlet from the heat exchange tube arrangement. | 05-06-2010 |
20100122540 | THERMOELECTRIC COOLER FOR ECONOMIZED REFRIGERANT CYCLE PERFORMANCE BOOST - A refrigerant system incorporates an economizer circuit, and a thermoelectric cooler to provide a performance boost to the conventional economized refrigerant system. A thermoelectric cooler cools the refrigerant either directly in a main refrigerant circuit, or in an economized circuit, or both. | 05-20-2010 |
20100139298 | MOTOR-COMPRESSOR DRIVE APPARATUS - Multiple compressors are connected to a common shaft of a drive motor. Provision may be made for selectively disengaging one or more of the compressors from its drive connection. The multiple compressors an preferably attached to opposite ends of a common motor shaft extending from both ends of the motor. Multiple compressors may be arranged to operate in parallel flow relationship or in series flow relationship in a single refrigerant circuit. The compressors may also be installed on separate refrigerant circuits. In a series flow relationship, a vapor or liquid injection function may be provided. Both compressors may be of an open-drive design, or one of the compressors nay share a common housing with the motor. | 06-10-2010 |
20100146990 | THERMOELECTRIC COOLER FOR COMPRESSOR MOTOR - A refrigerant system has an electric motor positioned either inside or outside of a hermetically sealed shell containing a compressor pump unit and is mechanically coupled to drive this compressor pump unit. The electric motor has at least one thermoelectric cooler to cool, or assist in cooling, of at least one component of the electric motor. | 06-17-2010 |
20100147006 | REFRIGERANT SYSTEM WITH CASCADED CIRCUITS AND PERFORMANCE ENHANCEMENT FEATURES - An improved refrigerant system incorporates at least two circuits arranged in a cascaded relationship. Preferably, the upper circuit utilizes a hydrocarbon refrigerant and preferably the lower circuit utilizes CO | 06-17-2010 |
20100170271 | REFRIGERANT SYSTEM - The present disclosure provides a method of operation of a refrigerant system, which comprises a main refrigerant circuit, a reheat circuit, and a flow control device, which has a first position isolating said reheat circuit from said main refrigerant circuit, and a second position placing said reheat circuit in fluid communication with said main refrigerant circuit. The refrigerant system further comprises a controller in electrical communication with said flow control device. The controller is configured to move the flow control device to the first position during a cooling mode, and to move the flow control device to the second position during a reheating mode or an oil recovery mode. The refrigerant system controller can execute an oil recovery mode in continuous or intermittent manner. | 07-08-2010 |
20100175396 | OIL RETURN IN REFRIGERANT SYSTEM - To address the problem of lubricant entrainment within the refrigerant system components such as an evaporator and suction line, a control is provided to periodically, substantially and intermittently increase the refrigerant flow through these components to thereby carry the trapped lubricant back to the compressor. The increased flow of refrigerant can be accomplished by periodically throttling and then unthrottling either an expansion device or a suction modulation valve to cause instantaneous pressure buildup within a respective section of the vapor compression system and subsequent increase of the refrigerant flow through the above-referenced components such as an evaporator and suction line. Suggested time intervals of both the throttling and unthrottling states are provided, as well as the frequency of occurrence for subsequent oil return cycles. | 07-15-2010 |
20100199686 | THERMOELECTRIC DEVICE FOR DEFOGGING AND DEFROSTING APPLICATIONS - A controlled surface having a direct contact with a flow of cold air circulating within a climate-controlled space is provided. A thermoelectric device is associated with the controlled surface and has a hot junction positioned upstream in the path of the air stream moving over the controlled surface and a cold junction positioned downstream in the path of the air stream. This arrangement provides defogging, defrosting or condensate evaporation for the controlled surface, while the temperature in the climate-controlled space is not appreciably altered, and at least some amount of moisture is removed from the air stream by the thermoelectric device. | 08-12-2010 |
20100199694 | REFRIGERANT SYSTEM WITH INTERCOOLER AND LIQUID/VAPOR INJECTION - A refrigerant system is provided with at least two sequential stages of compression. An intercooler is positioned intermediate the two stages. The refrigerant flowing through the intercooler is cooled by a secondary fluid such as ambient air. A vapor/liquid injection function is also provided for the refrigerant system. The intercooler function and the vapor/liquid injection function are selectively activated on demand depending on environmental conditions and thermal load in a conditioned space. This invention is particularly important for the CO2 refrigerant systems operating in the transcritical cycle. | 08-12-2010 |
20100199712 | REFRIGERANT VAPOR COMPRESSION SYSTEM OPERATING AT OR NEAR ZERO LOAD - A method is provided for operating a refrigerant vapor compression system at substantially zero cooling capacity to facilitate tight temperature control within a climate-controlled environment associated with the refrigerant vapor compression system. The method includes the step of diverting substantially all refrigerant flow from the primary refrigerant flow circuit of the refrigerant vapor compression system at a first location downstream, with respect to refrigerant flow, of the heat rejection heat exchanger and upstream, with respect to refrigerant flow, of the evaporator refrigerant expansion device to reenter the primary refrigerant flow circuit at a second location downstream, with respect to refrigerant flow, of the evaporator and upstream, with respect to refrigerant flow, of the compression device. | 08-12-2010 |
20100199715 | REFRIGERANT SYSTEM WITH BYPASS LINE AND DEDICATED ECONOMIZED FLOW COMPRESSION CHAMBER - A refrigerant system has an economizer cycle. A vapor refrigerant from the economizer loop is returned to a dedicated economizer compression chamber. A main refrigerant is returned to a dedicated main compressor chamber. A bypass line communicates the two refrigerant flows. | 08-12-2010 |
20100206868 | HEAT PUMP WITH HEAT RECOVERY - A fuel cell is provided to furnish electrical power to an HVAC&R system, and the waste heat from the fuel cell is transferred to a secondary fluid directed to flow to the climate-controlled space of a building during periods of time in which heating is required. The heat rejected by the fuel cell may be a supplemental or primary source of heat as well used for precise temperature control within the climate-controlled space of the building. A channeling assembly is used to selectively direct the fuel cell heat either to and/or away from the climate-controlled space served by the HVAC&R system. Higher energy efficiencies of the HVAC&R equipment are achieved, and the “cold blow” phenomenon is reduced or eliminated. | 08-19-2010 |
20100212337 | ENGINE DRIVEN REFRIGERANT COMPRESSOR WITH PULSE WIDTH MODULATION CONTROL - A fuel-powered engine is provided to drive a mobile air conditioning or refrigeration unit such as a portable chiller, a container refrigeration unit, a portable packaged system, a transport tractor-trailer or truck refrigeration unit, etc. A control rapidly changes the engine speed between the predefined set of discreet engine speeds to precisely adjust the capacity of the refrigerant system. If the engine operates only at a single speed, then the control cycles the engine between this operating speed and a zero speed (the engine is shut off). If the engine can operate at multiple discreet speeds, then the control can cycle the engine between any of these speeds (including a zero speed). When a lower capacity is desirable, the engine operates for a longer time interval at a lower speed, and when a higher capacity is desirable, the engine operates for a longer period of time at a higher speed. The cycle rate is selected to control the comfort (e.g. temperature and/or humidity) of the conditioned environment within the specified tolerance band, while conforming to the reliability requirements. | 08-26-2010 |
20100215516 | PULSATION ATTENUATION IN SYSTEMS WITH MULTIPLE COMPRESSION ELEMENTS - In compression systems having multiple sources of pulsation induced noise, provisions are made to reduce the noise by selectively varying the length of adjacent refrigerant lines leading to a common refrigerant manifold. Each of the refrigerant lines is associated with a particular noise source. The feature can be incorporated into compressors operating in parallel or in a single multi-rotor compressor having multiple suction or/and discharge ports. It is equally applicable to both discharge and suction ports. | 08-26-2010 |
20100236262 | METHOD AND APPARATUS FOR IMPROVING DEHUMIDIFICATION - Comfort temperature and humidity levels in a conditioned space are controlled by cycling the speed of an evaporator fan motor in such a manner that, during time periods when higher sensible capacity is desired, the time in which the fan motor operates at a higher speed is increased, and during time periods when a higher latent capacity is desired, the time in which the fan motor operates at a lower speed is increased. The fan motor may be a single speed motor that is switched between on and off positions, or it may be a multiple speed motor that is cycled between a higher speed and a lower speed. | 09-23-2010 |
20100236264 | COMPRESSOR MOTOR CONTROL - A compressor, which is susceptible to protective shutdowns when certain operating conditions are sensed, includes a control feature wherein, when the compressor is restarted after a period of time, it may be caused to operate in an unloaded mode such that a reoccurrence of the shutdowns is less likely. | 09-23-2010 |
20100242508 | USE OF AN ADJUSTABLE EXPANSION VAVLE TO CONTROL DEHUMIDIFICATION - A refrigerant system is provided with a control for its expansion device. The control operates the expansion device to adjust the superheat of the refrigerant leaving an evaporator to have desired dehumidification for air being delivered into an environment to be conditioned. | 09-30-2010 |
20100242509 | AIR ROUTING FOR SIMULTANEOUS HEATING AND COOLING - In an enclosed space which requires refrigeration or cooling at the same time when the heating of air is required, provision is made to divert at least a portion of the flow of heated air from the air conditioning/refrigeration heat rejection heat exchanger to the climate-controlled zone which requires heating. An airflow control device, such as one or more dampers, is provided for controlling the amount of heated air delivered to the climate-controlled-zone. | 09-30-2010 |
20100250009 | CONTROL OF CONDITIONED ENVIRONMENT BY REMOTE SENSOR - A comfort HVAC or refrigeration system includes a remote sensor for sensing an environmental condition within a climate-controlled space and having, an associated transmitter for sending, a wireless signal to a receiver of a controller such that the controller can then responsively modulate the operation of the components of the HVAC or refrigeration system to maintain a desired condition at a specific location or locations within the-climate-controUed'space. The desired condition can be, for instance, temperature, humidity and/or carbon dioxide level. | 09-30-2010 |
20100251750 | ECONOMIZED REFRIGERANT SYSTEM WITH FLOW CONTROL - A refrigerant vapor compression system has a primary refrigerant circuit including a compression device, a refrigerant heat rejection heat exchanger and a refrigerant heat absorption heat exchanger, and an economizer circuit including an economizer refrigerant line. A bypass flow control device controls refrigerant vapor flow through a bypass line extending between the economizer refrigerant line and a suction pressure portion of the primary refrigerant circuit. A flow control apparatus operatively associated with the economizer refrigerant line provides different flow resistance to refrigerant flow through the economizer refrigerant line in a first direction from an intermediate stage of the compression device to the suction portion of the primary refrigerant circuit and in a second direction from the economizer into an intermediate pressure stage of the compression device. | 10-07-2010 |
20100307172 | REFRIGERANT SYSTEM WITH REHEAT REFRIGERANT CIRCUIT - A refrigerant system is provided that includes a cooling refrigerant circuit, a reheat refrigerant circuit, an evaporator fan, and a controller. The evaporator fan forces indoor air in a first direction and a second direction. The indoor air passes across the evaporator before the reheat coil, in the first direction, but passes across the reheat coil before the evaporator, in the second direction. The controller, when in a conventional cooling mode, controls the reheat refrigerant circuit so that the reheat refrigerant circuit is not in fluid communication with the cooling refrigerant circuit and controls the evaporator fan to force the indoor air in the first direction. Conversely, the controller, when in a defrost mode, controls the reheat refrigerant circuit so that the reheat refrigerant circuit is in fluid communication with the cooling refrigerant circuit and controls the evaporator fan to force the indoor air in the second direction. | 12-09-2010 |
20100307177 | RAPID COMPRESSOR CYCLING - A single speed compressor is provided with a switching device and control for turning the compressor drive motor ON and OFF in repeated succession at a selected ON time/OFF time ratio within a selected cycle time interval. The ON/OFF ratio and cycle time interval are selected to maintain desired temperature and/or humidity control within a conditioned space. | 12-09-2010 |
20100319372 | PULSE WIDTH MODULATION WITH REDUCED SUCTION PRESSURE TO IMPROVE EFFICIENCY - The present invention relates to a way of reducing the amount of energy required to partially compress a refrigerant in a compressor operating in a rapidly cycled unloaded mode. A valve on a suction line is closed when the compressor moves to the unloaded condition. In this manner, the amount of energy required to partially compress the refrigerant in the compressor, at the unloaded condition, is dramatically reduced. | 12-23-2010 |
20100326100 | REFRIGERANT VAPOR COMPRESSION SYSTEM - A refrigerant vapor compression system includes a first compression device, a refrigerant heat rejection heat exchanger, an expansion device, a refrigerant heat absorption heat exchanger, a second compression device, and a refrigerant-to-refrigerant heat exchanger having first refrigerant flow pass, a second refrigerant flow pass and a third refrigerant flow pass, with the second refrigerant flow pass disposed in heat exchange relationship with each of the first refrigerant flow pass and the third refrigerant flow pass. The second refrigerant flow pass is interdisposed in an economizer circuit. The heat transfer interaction between the first and second refrigerant flow passes functions as a subcooler of refrigerant flowing to the refrigerant heat absorption heat exchanger and the heat transfer interaction between the second and third refrigerant flow passes functions as an intercooler of refrigerant passing from the discharge outlet of the second compression device to the suction inlet of the first compression device. | 12-30-2010 |
20110030399 | REFRIGERANT SYSTEM WITH FUEL CELL FOR ELECTRICITY GENERATION - A transport refrigeration/air conditioning system includes a fuel cell which is electrically connected to at least one of the compressor drive motor, evaporator fan motor or condenser fan motor to provide electrical power thereto. | 02-10-2011 |
20110041523 | CHARGE MANAGEMENT IN REFRIGERANT VAPOR COMPRESSION SYSTEMS - A refrigerant vapor compression system includes a compression device, a refrigerant heat rejection heat exchanger, an expansion device, and a refrigerant heat absorption heat exchanger disposed in a closed-loop refrigerant circuit in serial refrigerant flow relationship. A refrigerant storage device is connected by at least one refrigerant line in fluid communication with the refrigerant circuit and a flow control device interdisposed in that refrigerant line. Refrigerant may be selectively withdrawn from and returned to the high-pressure side of the refrigerant circuit; or withdrawn from and returned to the low-pressure side of the refrigerant circuit; or withdrawn from the high-pressure side of the refrigerant circuit and returned to the low-pressure side of the refrigerant circuit. The refrigerant may be withdrawn from and returned to the refrigerant circuit during operation or during an off-cycle. | 02-24-2011 |
20110041524 | REFRIGERANT SYSTEM PERFORMANCE ENHANCEMENT BY SUBCOOLING AT INTERMEDIATE TEMPERATURES - A refrigerant system operates in an environment defined by three distinct temperature levels, such as, for instance, the outdoor ambient temperature level, the indoor temperature level and the refrigeration temperature level. The refrigerant system is provided with an air-to-refrigerant heat exchanger located within the general indoor environment and connected to receive the flow of refrigerant from a heat rejection heat exchanger. The air-to-refrigerant heat exchanger gives off heat to the indoor air and in the process further cools the refrigerant flowing to an expansion device to thereby increase the cooling effect provided by an evaporator to the refrigeration area. Provisions are also made to partially or entirely bypass the air-to-refrigerant heat exchanger and/or the heat rejection heat exchanger, on a selective basis. | 02-24-2011 |
20110056667 | INTEGRATED MULTI-CIRCUIT MICROCHANNEL HEAT EXCHANGER - A microchannel heat exchanger has at least two manifolds, with the at least two manifolds communicating with a respective one of a first and second plurality of heat exchange tube banks. The first and second plurality of heat exchange tube banks are intertwined within a single microchannel heat exchanger core. | 03-10-2011 |
20110056668 | MODULAR HEAT EXCHANGER - A modular multi-channel tube heat exchanger includes a plurality of aluminum heat exchanger modules selectively connected in fluid communication by interconnecting tubing. Each heat exchanger module includes an aluminum inlet header, an aluminum outlet header and a plurality of aluminum heat exchange tubes extending longitudinally therebetween. Each of the plurality of heat exchange tubes may have a plurality of flow paths extending longitudinally in parallel relationship from an inlet end thereof in fluid communication with the inlet header to an outlet end thereof in fluid communication with the outlet header. | 03-10-2011 |
20110079032 | HEAT PUMP WITH MICROCHANNEL HEAT EXCHANGERS AS BOTH OUTDOOR AND REHEAT EXCHANGERS - A heat pump refrigerant system has a compressor for delivering a compressed refrigerant to a reversing refrigerant flow control device. The reversing refrigerant flow control device selectively delivers refrigerant to an outdoor heat exchanger in a cooling mode of operation, and to an indoor heat exchanger in a heating mode of operation. Refrigerant from an outdoor heat exchanger passes through an expansion device to an indoor heat exchanger in a cooling mode, and from the indoor heat exchanger through an expansion device and to the outdoor heat exchanger in a heating mode. A reheat circuit includes a reheat heat exchanger positioned to be in the path of air delivered over the indoor heat exchanger and into an environment to be conditioned. The reheat heat exchanger and outdoor heat exchanger both are provided by microchannel heat exchangers. The reheat circuit is utilized to minimize or prevent refrigerant charge migration while operating at a wide spectrum of environmental conditions or switching between modes of operation. | 04-07-2011 |
20110094248 | Refrigerant System and Method of Operating the Same - The present disclosure provides a refrigerant system that comprises a compressor, a main refrigerant circuit, an economizer refrigerant circuit, and a bypass refrigerant circuit. The refrigerant system further comprises a single refrigerant flow control device switching between different operational modes to provide various degree of system unloading in operation. The present disclosure also provides a method of operating the refrigerant system. | 04-28-2011 |
20110094259 | MULTI-STAGE REFRIGERANT SYSTEM WITH DIFFERENT COMPRESSOR TYPES - Multi-stage refrigerant systems operate with a lower stage compressor of a first type and a higher stage compressor of a second type. In one embodiment, the lower stage compressor type is selected to have the most beneficial characteristics at lower pressure operation, while the higher pressure stage compressor type is selected to have the most beneficial characteristics at higher pressure operation. | 04-28-2011 |
20110100035 | TWO-PHASE SINGLE CIRCUIT REHEAT CYCLE AND METHOD OF OPERATION - A refrigerant system has a refrigerant circuit comprising a compressor for compressing a refrigerant and delivering it downstream to a condenser. A bypass line is provided around the condenser for selectively allowing at least a portion of refrigerant to bypass the condenser. Valves are provided on a line leading to the condenser and on the bypass line to individually control the flow of refrigerant. An expansion device is located downstream of the condenser, and an evaporator is located downstream of the expansion device. A reheat cycle is incorporated into the system. The reheat cycle includes a valve for selectively delivering at least a portion of refrigerant through a reheat heat exchanger, which is positioned in the path of air downstream of the evaporator. A control is provided for the system to achieve a desired level of dehumidification and temperature control to air being delivered into the environment to be conditioned. | 05-05-2011 |
20110132015 | DEDICATED PULSING VALVE FOR COMPRESSOR CYLINDER - A reciprocating piston compressor for use in a refrigerant compression circuit comprises first and second intake manifolds, first and second reciprocating piston compression units, an outlet manifold and a first pulsing valve. The intake manifolds segregate inlet flow into the compressor. The first and second reciprocating piston compression units receive flow from the first and second intake manifolds, respectively. The outlet manifold collects and distributes compressed refrigerant from the compression units. The first pulsing valve is mounted externally of the first intake manifold to regulate refrigerant flow into the first intake manifold. In another embodiment, a second valve is mounted externally of the second intake manifold to regulate flow into the second intake manifold, and the first and second valves are operated by a controller. The controller activates the first valve with variable width pulses having intervals less than an operating inertia of the refrigerant compression circuit. | 06-09-2011 |
20110138826 | DISCRETE FREQUENCY OPERATION FOR UNIT CAPACITY CONTROL - A variable speed electric drive for use in refrigerant systems includes an electric motor for driving an associated component at a variable speed that is a function of an operating frequency of the motor; and a control for supplying alternating discrete drive frequencies to the electric motor to provide a continuously variable speed drive of the associated component. The control cycles the drive frequency to the electric motor among the at least two discrete frequencies so that the variable average resultant speed at which the associated component is driven is a function of a combination of the selected at least two discrete frequencies. | 06-16-2011 |
20110138827 | IMPROVED OPERATION OF A REFRIGERANT SYSTEM - A method and system for operating a refrigerant system having a reciprocating compressor with a main cylinder module and an economizer cylinder module includes regulating a flow of refrigerant into the main cylinder module and regulating a flow of refrigerant into the economizer cylinder module. The main cylinder module and the economizer cylinder module have separate inlet and outlet discharge streams. The flow through each module is regulated as a function of an operating mode of the refrigerant system, which includes various modes of loading and unloading based, in part, on a cooling demand. In some embodiments, the refrigerant system may include a connector refrigerant line configured to redirect refrigerant from the economizer cylinder module to the main cylinder module or from the main cylinder module to the economizer cylinder module. | 06-16-2011 |
20110185753 | SUPERHEAT CONTROL FOR HVAC&R SYSTEMS - A superheat control utilizes a sensor at a location downstream of an evaporator after some heat is delivered to the refrigerant. In one embodiment, the compressor is a sealed compressor with at least a portion of the refrigerant being heated by an electric motor. The temperature is sensed after the refrigerant temperature has increased after passing over the electric motor. In another embodiment, the refrigerant temperature is measured after some minimal compression and minimal temperature rise has occurred within the compressor pumping elements. In either case, by measuring the temperature of the refrigerant after some additional heat has been added to the refrigerant, the refrigerant super-heat leaving the evaporator can be controlled to a lower value. The improved superheat control enhances the system performance by increasing system efficiency, system capacity and improving oil return to the compressor. | 08-04-2011 |
20110209485 | SUCTION SUPERHEAT CONROL BASED ON REFRIGERANT CONDITION AT DISCHARGE - A relationship is developed between a discharge condition of a refrigerant leaving a compressor, and the suction superheat or refrigerant quality. By relying upon measurement and control of the discharge condition, the present invention is able to achieve very low suction superheat values. Controlling the operation to very low suction superheat values results in augmented refrigerant system performance. | 09-01-2011 |
20110214439 | TANDEM COMPRESSOR OF DIFFERENT TYPES - A refrigerant system having tandem compressors includes at least two compressors of different types. By utilizing the two distinct compressor types, a greater difference in the provided capacity of the two compressors can be achieved at part-load conditions, as well as a particular compressor type can be engaged at specific environmental conditions to provide the most efficient operation of the refrigerant system. | 09-08-2011 |
20110262290 | SCREW COMPRESSOR WITH ASYMMETRIC PORTS - A multi-rotor screw compressor includes a housing, a sun rotor, and first and second planet rotors. The first planet rotor intermeshes with the sun rotor to define a first compression pair. The second planet rotor intermeshes with the sun rotor to define a second compression pair. The first and second compression pairs are rotatably mounted in the housing. The housing includes a first port, a portion of which is in communication with the first compression pair, and a second port, a portion of which is in communication with the second compression pair. The portions of the first and second ports which communicate with the first and second compression pairs have a different geometry for offsetting pulsations in a working fluid flowing through the ports. | 10-27-2011 |
20110314845 | TADEM COMPRESSOR OPERATION - A refrigerant system operates with tandem compressors. As is known, one or more of the tandem compressors can be shut down at part-load operating conditions when lower refrigerant system capacity is required. A control periodically engages at least one shut down tandem compressor for a short period of time. This increases the refrigerant mass flow of refrigerant throughout the refrigerant system to ensure that oil travels through the system and is not retained in the system. | 12-29-2011 |
20120011866 | REFRIGERANT VAPOR COMPRESSION SYSTEM WITH HOT GAS BYPASS - A refrigerant vapor compression system includes a hot gas bypass line establishing refrigerant vapor flow communication between the compression device and the refrigerant heat absorption heat exchanger, and bypassing the refrigerant heat rejection heat exchanger and the primary expansion device. A refrigerant vapor flow control device is interdisposed in the hot gas bypass line. The flow control device has at least a first open position in which refrigerant vapor flow may pass through the hot gas bypass line and a closed position in which refrigerant vapor flow may not pass through the hot gas bypass line. | 01-19-2012 |
20120073318 | Refrigerant System With Multiple Load Modes - A refrigerant system capable of operating at multiple capacity modes includes an evaporator, a multi-stage compressor assembly, a first fluid flow path, a second fluid flow path, a first valve, and a second valve. The multi-stage compressor assembly has a first stage and a second stage. The first fluid flow path extends from the evaporator to the first stage of the multi-stage compressor assembly. The second fluid flow path connects to the first fluid flow path and to the multi-stage compressor assembly between the first stage and the second stage. | 03-29-2012 |
20120107159 | Bypass Unloader Valve For Compressor Capacity Control - A reciprocating compressor includes a cylinder block, a cylinder head, and a bypass unloader valve assembly. The cylinder block has a cylinder disposed therein. The cylinder head is secured to the cylinder block overlying the cylinder and has a suction plenum and a discharge plenum in selective fluid communication with the cylinder. The bypass unloader valve assembly is in operable communication with the cylinder head and is responsive to control signals to rapid cycle to allow for fluid communication of a refrigerant between the discharge plenum and the suction plenum. | 05-03-2012 |
20120167602 | PRESSURE SPIKE REDUCTION FOR REFRIGERANT SYSTEMS INCORPORATING A MICROCHANNEL HEAT EXCHANGER - A refrigerant system includes at least one compressor ( | 07-05-2012 |
20120192583 | Suction Cutoff Unloader Valve For Compressor Capacity Control - A reciprocating compressor includes a first cylinder and a second cylinder, first and second suction cutoff unloader valve assemblies, and a controller. The first and second suction cutoff unloader valve assemblies are integral to the compressor and are capable of a rapid cycling to interrupt flow of refrigerant to the first and second cylinders. The controller operates at least one of the first suction cutoff unloader valve assembly or second suction cut-off unloader valve assembly in the rapid cycling and monitor a number of rapid cycles. In another aspect, a multi-stage compressor comprises a lower pressure stage and a higher pressure stage, and at least one suction cutoff unloader valve assembly capable of a rapid cycling to interrupt flow of refrigerant to a lower stage cylinder. | 08-02-2012 |
20120247141 | Reciprocating Refrigeration Compressor Oil Sealing - A compressor ( | 10-04-2012 |
20120266610 | PERFORMANCE AND POSITION MONITORING OF A MOBILE HVAC&R UNIT - A system for monitoring a mobile refrigerant system including one or more system components is provided. The system includes a global positioning system, a performance monitor, and a processor. The global positioning system includes a receiver that provides a locator signal. The performance monitor provides a monitor signal indicative of operational performance of at least one of the system components of the refrigerant system. The processor is adapted to receive and combine the locator signal and the monitor signal, and produce a combined locator and monitor signal output. | 10-25-2012 |
20120291462 | Ejector Cycle Refrigerant Separator - A system has a compressor. A heat rejection heat exchanger is coupled to the compressor to receive refrigerant compressed by the compressor. An ejector has a primary inlet coupled with heat rejection heat exchanger to receive refrigerant, a secondary inlet, and an outlet. The system has a heat absorption heat exchanger. The system includes means for providing at least of a 1-10% quality refrigerant to the heat absorption heat exchanger and an 85-99% quality refrigerant to at least one of the compressor and, if present, a suction line heat exchanger. | 11-22-2012 |
20130031934 | REFRIGERANT VAPOR COMPRESSION SYSTEM WITH INTERCOOLER - A refrigerant vapor compression system includes a compression device having at least a first compression stage and a second compression stage, a refrigerant heat rejection heat exchanger disposed downstream with respect to refrigerant flow of the second compression stage, and a refrigerant intercooler disposed intermediate the first compression stage and the second compression stage. The refrigerant intercooler is disposed downstream of the refrigerant heat rejection heat exchanger with respect to the flow of a secondary fluid. A second refrigerant heat rejection heat exchanger may be disposed downstream with respect to refrigerant flow of the aforesaid refrigerant heat rejection heat exchanger, and a second refrigerant intercooler may be disposed intermediate the first compression stage and the second compression stage and downstream with respect to refrigerant flow of the aforesaid refrigerant intercooler. | 02-07-2013 |
20130256423 | Heating System Including A Refrigerant Boiler - A heating system includes a refrigerant boiler including a heat source for heating a refrigerant from a liquid state to a vapor state, a boiler outlet and a boiler inlet; a heat exchanger in fluid communication with the refrigerant boiler, the heat exchanger including a upper manifold having a heat exchanger inlet coupled to the boiler outlet, a lower manifold having a heat exchanger outlet coupled to the boiler inlet and a plurality of tubes connecting the upper manifold and the lower manifold, wherein refrigerant passes from the upper manifold to the lower manifold via gravity; and a fan moving air over the heat exchanger to define supply air for a space to be heated. | 10-03-2013 |