Patent application number | Description | Published |
20080233437 | Fuel Cell System and Control Method Therefor - A fuel cell system preferably includes a fuel cell which generates electric energy by electrochemical reaction, an aqueous solution tank which holds the methanol aqueous solution, a water tank which holds fluid discharged from the fuel cell, a fluid level sensor for detecting an amount of fluid in the water tank, a water pump which recycles fluid in the water tank to the aqueous solution tank, and a CPU which controls components of the fuel cell system. After power generation is finished, the water pump is driven to recycle all the fluid in the water tank to the aqueous solution tank. Further, after power generation is finished or before power generation is started, the fluid level sensor detects the amount of fluid in the water tank. If the amount of fluid is not smaller than a predetermined amount, the water pump is driven to recycle fluid in the water tank to the aqueous solution tank. The fuel cell system has a simple construction and is capable of preventing fluid from being discharged outside. | 09-25-2008 |
20080238355 | FUEL CELL SYSTEM AND OPERATION METHOD THEREFOR - A motorbike is mounted with a fuel cell system which includes a cell stack, a secondary battery which is charged by the cell stack and a controller which has a CPU. After receiving an operation stop command which is issued from a main switch, the CPU estimates a charging time for a charge rate of the secondary battery to attain a target value, based on a voltage of the secondary battery and a charge current which are detected based on detection signals from a voltage detection circuit and an electric current detection circuit, as well as based on a charging time estimation table stored in a memory. The charging time estimated by the CPU is displayed in a display. | 10-02-2008 |
20080268311 | FUEL CELL SYSTEM - A fuel cell system includes a cell stack, a temperature sensor which detects a temperature of the cell stack, an outside air temperature sensor which detects an outside air temperature, and a CPU which controls a process in the fuel cell system. When the temperature of the cell stack is lower than a predetermined temperature, the fuel cell system performs a temperature raising operation of the cell stack by making the concentration of aqueous methanol solution in an aqueous solution tank higher than in a normal operation and by making an output of an aqueous solution pump greater than in the normal operation. The CPU sets a run time for the temperature raising operation based on a detection result from the outside air temperature sensor, a detection result from the temperature sensor, and a run time setting table which is stored in a memory. The fuel cell system is capable of raising a temperature of the fuel cell quickly and stably to the predetermined temperature. | 10-30-2008 |
20090061269 | FUEL CELL SYSTEM AND CONTROL METHOD THEREFOR - A fuel cell system is arranged to charge a secondary battery, which is detachable from the fuel cell system, and to supply electric power to a load. The fuel cell system includes a cell stack having a plurality of fuel cells and a controller having a CPU. During power generation in the cell stack, the CPU determines whether or not the secondary battery has been removed from the fuel cell system based on a voltage drop in the cell stack. With the determination that the secondary battery has been removed, the CPU turns off a relay and power supply from the cell stack to the load is stopped. The fuel cell system reliably maintains its operation even after removal of the secondary battery. | 03-05-2009 |
20090123785 | FUEL CELL SYSTEM AND CONTROL METHOD THEREFOR - A fuel cell system and a control method therefor are capable of improving power generation efficiency of the fuel cell more reliably during a normal operation. A fuel cell system is arranged along a vehicle frame of a motorcycle. The fuel cell system includes a fuel cell having a cathode, an air pump which supplies the cathode with oxygen-containing air, and a CPU which controls operation of elements which constitute the fuel cell system. The CPU determines, depending on situations, whether or not to perform an oxygen-starving process which is a process of starving the cathode of the oxidizer during the normal operation, and stops the air pump when a determination is made to perform the oxygen-starving process. | 05-14-2009 |
20090130497 | FUEL CELL SYSTEM AND STARTING METHOD THEREFOR - A fuel cell system and a starting method therefor are capable of setting a start-up mode which is appropriate to energy stored in a secondary battery so as to eliminate problems in starting the fuel cell system. The fuel cell system includes a fuel cell, a secondary battery which is electrically connected with the fuel cell, a secondary-battery charge-amount detection unit which detects an amount of charge in the secondary battery, and a memory which stores at least one threshold value for determining the start-up mode of the fuel cell system. Stored electric energy which corresponds to the amount of charge in the secondary battery is calculated, and a start-up mode of the fuel cell system is determined based on the electric energy stored in the secondary battery and the threshold value stored in the memory. | 05-21-2009 |
20090214903 | FUEL CELL SYSTEM AND CONTROL METHOD THEREOF - A fuel cell system includes a fuel cell which has an anode. A fuel supplying device circulates a supply of aqueous methanol solution to the anode in the fuel cell. The fuel supplying device includes an aqueous solution tank for storing the aqueous methanol solution. By moving aqueous methanol solution from the aqueous solution tank to a water tank, the amount of aqueous methanol solution which is in circulation at the time of start-up is made smaller than the amount for normal operation. The fuel cell system and a control method therefore are capable of shortening a time that is necessary for heating aqueous fuel solution to be supplied to the fuel cell to a predetermined temperature without reducing fuel utilization efficiency. | 08-27-2009 |
20090269635 | FUEL CELL SYSTEM - A fuel cell system which is capable of reducing deterioration of fuel cells is preferably mounted on a motorbike and includes a cell stack, a CPU, a voltage detection circuit, a current detection circuit, an external air temperature sensor, a humidity sensor, a concentration sensor and sonars. The CPU obtains a volume of a garage, an amount of temperature change, an amount of humidity change and an amount of methanol concentration change in external air, as well as an amount of output change in the cell stack based on detection results from the voltage detection circuit, the current detection circuit, the external air temperature sensor, the humidity sensor, the concentration sensor and the sonars. The CPU sets first through fifth duration times based on the volume of the garage and the various amounts of changes, selects the shortest duration time of the duration times, and then, stops power generation in the cell stack when the selected duration time has passed. | 10-29-2009 |
20090274934 | FUEL CELL SYSTEM AND STARTING METHOD THEREFOR - A fuel cell system and a starting method therefore prevent problems when the system is started. The fuel cell system includes a fuel cell, a secondary battery that is electrically connected with the fuel cell, and a cell temperature sensor that detects a temperature of the fuel cell. Energy which is necessary for starting the fuel cell system is calculated based on the temperature of the fuel cell detected by the cell temperature sensor. The calculated value is used as a threshold for determining a start-up mode of the fuel cell system. | 11-05-2009 |
20100167098 | FUEL CELL SYSTEM AND TRANSPORTATION EQUIPMENT INCLUDING THE SAME - A fuel cell system prevents leakage of aqueous fuel solution to the cathode while reducing catalyst deterioration in the fuel cell. The fuel cell system includes a fuel cell including an anode and a cathode. An aqueous solution pump supplies the anode with aqueous methanol solution whereas an air pump supplies the cathode with air. Where there is an abnormality in the fuel cell, a CPU stops operation of the aqueous solution pump, and thereafter stops operation of the air pump when a temperature of the fuel cell detected by a cell stack temperature sensor is not higher than a predetermined value. When starting the fuel cell system with an abnormality existing in the fuel cell, the CPU drives the air pump and thereafter drives the aqueous solution pump. | 07-01-2010 |