Abstract: The cooling capacity of a first heat exchanger for cooling a reformed gas introduced into an inlet of a circulation pump is increased as an output of a fuel cell increases. With this configuration, an inlet temperature of the circulation pump is relatively high during low power generation and decreases as the generation power increases, and a volumetric flow rate during high power generation in which a large amount of reformed gas is required can be decreased relatively. As the result, a dynamic range required for the circulation pump can be made small. Furthermore, water condensation in the inlet of the circulation pump can be prevented during low power generation.

Abstract: Disclosed is a fuel cell system which comprises a power generation means that includes a plurality of fuel cells that are connectable to one another in series or in parallel through connecting terminals, a fuel gas supply conduit through which fuel electrodes of all or part of the fuel cells are connected in series and an oxidant gas supply conduit through which air electrodes of all or part of the fuel cells are connected in series; a switching means that switches an electric connection condition between the connecting terminals and connecting means of an external load device; a fuel gas supply means that supplies the fuel gas supply conduit with a fuel gas and an oxidant gas supply means that supplies the oxidant gas supply conduit with an oxidant gas; a load detecting means that detects a load of the external load device; and a control means that selects, based on an already derived relation between overall electric power output curves corresponding to the number of the fuel cells that are mutually connect

Abstract: The cooling capacity of a first heat exchanger for cooling a reformed gas introduced into an inlet of a circulation pump is increased as an output of a fuel cell increases. With this configuration, an inlet temperature of the circulation pump is relatively high during low power generation and decreases as the generation power increases, and a volumetric flow rate during high power generation in which a large amount of reformed gas is required can be decreased relatively. As the result, a dynamic range required for the circulation pump can be made small. Furthermore, water condensation in the inlet of the circulation pump can be prevented during low power generation.

Abstract: A solid electrolyte fuel cell system includes a reformer to produce a hydrogen-rich reformed gas from fuel, oxygen and water, and a stack structure including a stack of fuel cell units each receiving supply of the reformed gas and air, and producing electricity. The fuel cell system further includes a reformed gas cooler to cool the reformed gas supplied from the reformer to the stack structure, and a temperature control section to control operation of the reformed gas cooler in accordance with an operating condition such as a request output of the stack structure. The reformed gas cooler includes a device such as a heat exchanger for cooling the reformed gas with a coolant such as air.

Abstract: Disclosed is a fuel cell system comprising a reformer and a fuel cell body to which a fuel gas reformed through the reformer and air are supplied and in which the supplied fuel gas and air are separated from each other and caused to flow and contact on respective electrodes to perform electric power generation. A moisture quantity adjustment device is configured to adjustably separate a portion of moisture included in the fuel gas supplied from the reformer in order for the moisture included in the fuel gas to be supplied to the fuel cell body in an appropriate quantity.

Abstract: Disclosed is a fuel cell system which comprises a power generation means that includes a plurality of fuel cells that are connectable to one another in series or in parallel through connecting terminals, a fuel gas supply conduit through which fuel electrodes of all or part of the fuel cells are connected in series and an oxidant gas supply conduit through which air electrodes of all or part of the fuel cells are connected in series; a switching means that switches an electric connection condition between the connecting terminals and connecting means of an external load device; a fuel gas supply means that supplies the fuel gas supply conduit with a fuel gas and an oxidant gas supply means that supplies the oxidant gas supply conduit with an oxidant gas; a load detecting means that detects a load of the external load device; and a control means that selects, based on an already derived relation between overall electric power output curves corresponding to the number of the fuel cells that are mutually connect

Abstract: Disclosed is a fuel cell system comprising a reformer and a fuel cell body to which a fuel gas reformed through the reformer and air are supplied and in which the supplied fuel gas and air are separated from each other and caused to flow and contact on respective electrodes to perform electric power generation. A moisture quantity adjustment device is configured to adjustably separate a portion of moisture included in the fuel gas supplied from the reformer in order for the moisture included in the fuel gas to be supplied to the fuel cell body in an appropriate quantity.

Abstract: A fuel reformer includes a reforming element (7) having at least one reforming catalyst passage (22) supporting a reforming catalyst which generates reformate gas from fuel; and a combustion element (8) having at least one combustion gas passage (11), which heats the reforming element (7) by the heat of combustion gas generated by burning the generated reformate gas supplied in air introduced in said at least one combustion gas passage (11). The reforming element (7) and combustion element (8) are laminated in the fuel reformer. The fuel reformer further includes plural supply holes (13) arranged in a line along said at least one combustion gas passage (11), each supply hole (13) communicating with said at least one combustion gas passage (11). At least part of the generated reformate gas is supplied to each supply hole, and is burnt downstream of each supply hole.

Abstract: A solid electrolyte fuel cell system includes a reformer to produce a hydrogen-rich reformed gas from fuel, oxygen and water, and a stack structure including a stack of fuel cell units each receiving supply of the reformed gas and air, and producing electricity. The fuel cell system further includes a reformed gas cooler to cool the reformed gas supplied from the reformer to the stack structure, and a temperature control section to control operation of the reformed gas cooler in accordance with an operating condition such as a request output of the stack structure. The reformed gas cooler includes a device such as a heat exchanger for cooling the reformed gas with a coolant such as air.

Abstract: A fuel cell control system of the present invention includes a fuel cell (10) using as the electrolyte (11) an ionic conductor containing a cation component, an anion component, and a polar substance; and a polar substance amount controller controlling an amount of the polar substance in the electrolyte (11) according to the operating condition of the fuel cell. The fuel cell control system can maintain high protonic conductance in all the ranges from the low-load operation range to the high-load operation range.

Abstract: A fuel reformer includes a reforming element (7) having at least one reforming catalyst passage (22) supporting a reforming catalyst which generates reformate gas from fuel; and a combustion element (8) having at least one combustion gas passage (11), which heats the reforming element (7) by the heat of combustion gas generated by burning the generated reformate gas supplied in air introduced in said at least one combustion gas passage (11). The reforming element (7) and combustion element (8) are laminated in the fuel reformer. The fuel reformer further includes plural supply holes (13) arranged in a line along said at least one combustion gas passage (11), each supply hole (13) communicating with said at least one combustion gas passage (11). At least part of the generated reformate gas is supplied to each supply hole, and is burnt downstream of each supply hole.

Abstract: An error learning value Dqsol* in an idle running state is calculated based on a difference Dqsol0 between a command signal Qsol2A when the engine is in the idle running state and an estimated fuel injection amount Qsolib necessary to maintain the idle running state. An injection amount error Dqsol1 is calculated from the error learning value Dqsol* and an estimated real injection amount Qsol.sub.-- real is calculated from the current command signal Qsol2 and the injection amount error Dqsol1. By varying the estimated fuel injection amount Qsolib according to a loading condition of said engine, a fuel injection amount can be estimated precisely in various running states.

Abstract: An intake pressure and exhaust pressure of an engine are predicted from a fresh air flowrate in a diesel engine comprising an exhaust gas recirculation system and a sensor for detecting the fresh air flowrate. A fault in the system is diagnosed based on the predicted intake pressure and exhaust pressure. Preferably, fault diagnosis in the exhaust gas recirculation system is based on a differential pressure between the intake pressure and exhaust pressure, or on a comparison of an estimated EGR rate and target EGR rate found from the intake pressure and exhaust pressure, without providing any special sensors. Smoke emission is also reduced by limiting the maximum fuel injection amount of the engine.

Abstract: A fuel delivery control apparatus for use with an internal combustion engine for controlling the amount of fuel metered to the engine based upon engine operating conditions. A control unit is provided for calculating an acceleration enrichment related correction factor from a relationship programmed into the control unit to correct the amount of fuel metered to the engine so as to provide acceleration enrichment for a predetermined period of time after the engine acceleration starts. This relationship defines the acceleration enrichment related correction factor as a function of selected engine operating conditions. The relationship is corrected based upon recent engine operating conditions.

Abstract: A system for detecting combustion state in an internal combustion engine, detects cylinder pressures in a detecting range from 120.degree. to 240.degree. of crank angle, i.e. from 60.degree. BTDC and 60.degree. ATDC positions, for respective cylinders by means of cylinder pressure sensors, to predict cylinder pressures in a range other than the detecting range in compression and expansion strokes. On the basis of these cylinder pressures, the system derives an indicated mean effective pressure P.sub.i.sup.+ i. This indicated mean effective pressure P.sub.i.sup.+ i is used for determining occurence of misfire in the engine.

Abstract: The throttle valve position is sensed and the effective cross sectional area of the induction passage determined via table look up. The value thus derived is divided by the engine speed. A basic air induction quantity is then determined via table look up and subsequently modified using a correction coefficient to allow for the effect of engine speed on the amount of air inducted into each cylinder. The effect of injector position (viz., MPI/SPI) is taken into consideration and values suited for both generated in given embodiments. In the event that the maximum induction vacuum is limited by a BCD valve or the like, an embodiment anticipates the change in induction characteristics based on the engine speed.

Abstract: In order to obviate the delay between a demand for transitory engine operation and the injection of the appropriate amount of fuel, an initial correction pulse width is generated in response to the change in throttle valve position is added to a basic width which is developed based on the output of an air flow meter located in an upstream section of the induction conduit. The system further provides for continuously updating correction factors which are applied to the throttle sensor to ensure linearity and generating weighting factors and the like which are appropriately applied to improve the air-fuel control.

Abstract: An air/fuel ratio control system detects transition of air/fuel ratio changing between rich and lean for checking if updating condition is satisfied. Updating value is derived based on a feedback correction value which is derived for adjusting air/fuel ratio toward a stoichiometric value. With the updating value thus derived, one of a plurality of learnt correction value which are set with respect to various engine driving range.

Abstract: A system and method for controlling a fuel injection quantity for an internal combustion engine are disclosed in which upon start of the engine acceleration, a quantity corresponding to an air quantity sucked into an engine cylinder (for example, a pressure in an intake air passage downstream of a throttle valve) is detected, an indicated mean effective pressure (P.sub.i) is detected, gains and phases of both detected values are matched with each other, respectively, so that an expected value of the indicated mean effective pressure is derived from the detected value of the air quantity corresponding quantity, a deviation between the expected value and detected value of the indicated mean effective pressure is derived, a correction quantity for a basic injection quantity at the time of an acceleration of a vehicle through the engine is derived on the basis of the deviation, and a fuel injection quantity outputted from a fuel injection valve is determined on the basis of the corrected fuel injection quantity.

Abstract: A system for measuring intake air amount to be introduced into an engine cylinder employs a throttle angle sensor as a basic intake air flow amount indicative factor. Basic intake air flow amount is derived on the basis of a throttle valve angular position and an engine speed. The basic intake air flow amount is corrected with taking delay factor to introduce the intake air past the throttle valve into the engine cylinder, and a temperature dependent factor compensating variation of air density depending upon the temperature condition.