Abstract: A heat exchanger for the air supply circuit of a motor vehicle engine includes a heat exchange core and at least one header tank. The heat exchanger also includes an air flow rate control valve arranged in the header tank of the exchanger, and the control valve is a valve that includes a body with three openings and a moving rotary member inside the body so as to control the circulation of air through the heat exchange core and/or through a duct bypassing the heat exchange core according to a law defined as a function of the angular position of the rotary member in the body.

Abstract: A heat exchanger (10?) for the air supply circuit of a motor vehicle engine, comprises a heat exchange core (100) and at least one header tank (210?). The heat exchanger (10?) comprises an air flow rate control valve (300) arranged in the header tank (210?) of the exchanger, and the control valve (300) is a valve comprising a body (310) with three openings (311; 313) and a moving rotary member (320) inside the body (310) so as to control the circulation of air through the heat exchange core (100) and/or through a duct (13?) bypassing the heat exchange core (100) according to a law defined as a function of the angular position of the rotary member (320) in the body (310). The heat exchanger (10?) is particularly applicable to motor vehicles with a supercharged engine.

Abstract: A method and apparatus increase the temperature of a fuel cell via reactant starvation at one or both electrodes. Reactant starvation at an electrode results in an increased overvoltage at the electrode and hence increased internal heat generation under load. Further, starvation techniques may be used to prevent poisoning of electrode catalysts, a potential problem that is aggravated at lower temperatures. Starvation conditions can be prolonged or intermittent and can be obtained, for example, by suitably reducing the supply rate of a reactant or by operating the fuel cell at sufficiently high current density so as to consume reactant faster than it is supplied. The method can allow for some generation of useful power by the fuel cell during start-up. The method is particularly suitable for starting up a solid polymer electrolyte fuel cell from temperatures below 0° C.

Abstract: A method and apparatus increase the temperature of a fuel cell via reactant starvation at one or both electrodes. Reactant starvation at an electrode results in increased internal heat generation under load. Starvation conditions can be prolonged or intermittent and can be obtained, for example, by suitably reducing the supply rate of a reactant or by operating the fuel cell at sufficiently high current density so as to consume reactant faster than it is supplied. The method can allow for some generation of useful power by the fuel cell during start-up. The method is particularly suitable for starting up a solid polymer electrolyte fuel cell from temperatures below 0° C.

Abstract: A method and apparatus increase the temperature of a fuel cell via reactant starvation at one or both electrodes. Reactant starvation at an electrode results in an increased overvoltage at the electrode and hence increased internal heat generation under load. Starvation conditions can be prolonged or intermittent and can be obtained, for example, by suitably reducing the supply rate of a reactant or by operating the fuel cell at sufficiently high current density so as to consume reactant faster than it is supplied. The method can allow for some generation of useful power by the fuel cell during start-up. The method is particularly suitable for starting up a solid polymer electrolyte fuel cell from temperatures below 0° C.

Abstract: A method and apparatus increase the temperature of a fuel cell via reactant starvation at one or both electrodes. Reactant starvation at an electrode results in an increased overvoltage at the electrode and hence increased internal heat generation under load. Further, starvation techniques may be used to prevent poisoning of electrode catalysts, a potential problem that is aggravated at lower temperatures. Starvation conditions can be prolonged or intermittent and can be obtained, for example, by suitably reducing the supply rate of a reactant or by operating the fuel cell at sufficiently high current density so as to consume reactant faster than it is supplied. The method can allow for some generation of useful power by the fuel cell during start-up. The method is particularly suitable for starting up a solid polymer electrolyte fuel cell from temperatures below 0° C.