JP2013080718A - Cooling system of fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling system of a fuel cell which enables cooperative control between a cooling system of a fuel cell stack and other heat exchange systems.SOLUTION: A cooling system 100 of a fuel cell is equipped with: a main cooling flow passage 102 through which coolant flows; and a bypass cooling flow passage 104 which is arranged parallel with the main cooling flow passage 102 and diverts the same coolant. A radiator 110, a coolant circulation pump (WP) 130 and the like are arranged in the main cooling flow passage 102. The coolant from the main cooling flow passage 102 enters the bypass cooling flow passage 104 and reaches a second heat exchanger 120 via a case and the like of a motor 50 of an air compressor (ACP) 48. At the second heat exchanger 120, heat exchange is also performed for a supply gas flow passage 80, after which the coolant returns to the main cooling flow passage 102. The manner in which the coolant is distributed can be changed variously depending on how the coolant is diverted from the main cooling flow passage 102 and how the circulation pump 130 is arranged.

Description

  The present invention relates to a fuel cell cooling system, and more particularly, to a fuel cell cooling system in which fuel gas is supplied to an anode side and oxidizing gas is supplied to a cathode side to generate electric power by an electrochemical reaction.

  Since there is little impact on the environment, fuel cells are installed in vehicles. In the fuel cell, for example, a fuel gas such as hydrogen is supplied to the anode side of the fuel cell stack, an oxidizing gas containing oxygen such as air is supplied to the cathode side, and necessary electric power is taken out by a reaction through the electrolyte membrane. The fuel cell generates heat due to this reaction, and a coolant such as cooling water is allowed to flow through the fuel cell stack for cooling, and this is cooled with a radiator or the like. When the temperature of the fuel cell is low, the refrigerant is heated to an appropriate temperature with a heater or the like in order to warm the fuel cell. In this way, the refrigerant is allowed to flow through the fuel cell stack and its temperature is adjusted.

  Further, a gas compressor such as an air compressor (ACP) is used in order to bring the oxidizing gas supplied to the cathode side of the fuel cell stack to an appropriate pressure. Since this ACP also generates heat in response to operation, it is cooled by a heat exchanger called an intercooler. Further, the vehicle is provided with a heat exchanger for air conditioning in the passenger compartment. As described above, since various heat exchangers having different purposes and objects are provided in the vehicle, their mutual use is worth considering.

  For example, Patent Document 1 discloses a fuel cell system that prevents water clogging while supplementing a humidification amount that is insufficient in a humidifier provided on the cathode side of the fuel cell. Here, the refrigerant for cooling the cathode supply gas and the refrigerant for cooling the fuel cell stack are shared, and the cathode supply gas cooling heat exchanger and the fuel cell stack are connected in series through the refrigerant flow path. Two three-way valves are installed in the middle of the refrigerant flow path so that the flow direction of the refrigerant can be changed depending on whether the temperature of the fuel cell is high or low.

  Patent Document 2 discloses an air conditioner and a fuel as a heat source that enable both comfortable air conditioning and sufficient cooling of the fuel cell device at a high outside temperature and easily compensate for heat shortage at a low outside temperature. A method for cooling and heating an automobile having a battery is disclosed. Here, both the cooling of the heat source and the air conditioning of the automobile use a common refrigerant and use a single refrigerant circuit. The media circuit branches into a first sub-circuit and a second sub-circuit at a branch point, the first sub-circuit is allocated to the fuel cell device, and the second sub-circuit is allocated to the automobile air conditioner, Reconnect at the connection point via. That is, the heat exchange of the fuel cell device and the heat exchange of the air conditioner are arranged in series in one loop.

JP 2005-79007 A JP 2005-514261 A

  In the prior art, when each heat exchanger is controlled independently, the refrigerant circuit and its control are independent of each other, which is inconvenient. If the cooling system of the fuel cell stack and the cooling system of the cathode supply gas are performed independently, the temperature of the cathode supply gas entering the fuel cell stack is determined by the cooling system of the cathode supply gas, and the cathode coming out of the fuel cell stack The temperature of the supply gas (so-called cathode off gas) is almost determined by the cooling system of the fuel cell stack. Here, if the two cooling systems are controlled independently, the temperature difference between the temperature of the cathode supply gas entering the fuel cell stack and the temperature of the cathode off gas may become too large.

  As a result, for example, the following problems may occur. That is, a humidifier is provided in parallel to the fuel cell stack in order to appropriately humidify the cathode supply gas and supply it to the fuel cell stack. However, the temperature difference between both ends of the humidifier may increase. . A humidifier having a well-known hollow fiber structure may be used, but this structure may be damaged if the temperature difference between both ends is large, and may not operate sufficiently. Thus, making the refrigerant circuit and its control independent of each heat exchanger of the fuel cell has a complicated structure, the use of the refrigerant is not efficient, and the above-described problems may occur.

  In the prior arts described in Patent Documents 1 and 2, sharing of the refrigerant for cooling the cathode supply gas and the refrigerant for cooling the fuel cell stack, cooling of the fuel cell as a heat source, and air conditioning in the vehicle interior Both disclose the use of a common refrigerant. In these technologies, the fuel cell stack and other cooling heat exchangers are arranged in the series cooling flow path to share the refrigerant, so that temperature adjustment such as cooling of the fuel cell stack is possible. The cathode supply gas and the temperature control in the passenger compartment depend on each other. Therefore, in these technologies, the efficiency of refrigerant utilization is improved, but since it is not possible to control each independently, it is difficult to optimize each temperature adjustment when each cooling system is controlled independently. It is the same.

  As described above, in the prior art, temperature adjustment such as cooling of the fuel cell stack and temperature adjustment of the cathode supply gas and the passenger compartment are not coordinated.

  An object of the present invention is to provide a fuel cell cooling system that enables coordinated control of a fuel cell stack cooling system and another heat exchange system.

  A fuel cell cooling system according to the present invention is a fuel cell cooling system in which a fuel gas is supplied to an anode side and an oxidizing gas is supplied to a cathode side to generate electric power by an electrochemical reaction, and includes a fuel cell stack and a radiator. And a second heat exchanger that is provided in parallel to the fuel cell stack with respect to the cooling channel and to which the refrigerant in the cooling channel is divided.

  The fuel cell cooling system according to the present invention is a fuel cell cooling system in which fuel gas is supplied to the anode side and oxidant gas is supplied to the cathode side to generate electric power by an electrochemical reaction, and includes a fuel cell stack and a radiator. And a second heat exchanger that is provided in parallel with the radiator and to which the refrigerant in the cooling channel is diverted.

  Moreover, it is preferable that a 2nd heat exchanger serves as the cooling device of the gas compressor for oxidizing gas supply.

  Further, in the fuel cell cooling system according to the present invention, the fuel cell is a vehicle fuel cell mounted on a vehicle, and an air conditioning heat exchanger for air conditioning in the passenger compartment is provided in parallel with the fuel cell stack, It is preferable that the refrigerant in the cooling flow path is divided.

  In the fuel cell cooling system according to the present invention, the refrigerant circulation pump arranged in series in the cooling flow path and the gas inlet and the gas outlet for supplying the oxidizing gas to the cathode side of the fuel cell are arranged in parallel. A humidifier, and the humidifier is disposed downstream of the refrigerant circulation pump and upstream of the fuel cell stack, and the second heat exchanger is downstream of the radiator and upstream of the refrigerant circulation pump. Is preferably incorporated.

  In the fuel cell cooling system according to the present invention, the refrigerant circulation pump arranged in series in the cooling flow path and the gas inlet and the gas outlet for supplying the oxidizing gas to the cathode side of the fuel cell are arranged in parallel. A humidifier, and the humidifier is disposed downstream of the refrigerant circulation pump and upstream of the fuel cell stack, and the second heat exchanger is downstream of the refrigerant circulation pump and from the upstream side of the humidifier. It is preferred that a refrigerant be incorporated.

  In the fuel cell cooling system according to the present invention, the refrigerant circulation pump arranged in series in the cooling flow path and the gas inlet and the gas outlet for supplying the oxidizing gas to the cathode side of the fuel cell are arranged in parallel. A humidifier, the humidifier is disposed upstream of the refrigerant circulation pump and downstream of the radiator, and the second heat exchanger is downstream of the radiator and receives refrigerant from the upstream side of the humidifier. Preferably incorporated.

  In the fuel cell cooling system according to the present invention, the refrigerant circulation pump arranged in series in the cooling flow path and the gas inlet and the gas outlet for supplying the oxidizing gas to the cathode side of the fuel cell are arranged in parallel. A humidifier, the humidifier is disposed downstream of the refrigerant circulation pump and upstream of the fuel cell stack, and the air conditioning heat exchanger is downstream of the humidifier and upstream of the fuel cell stack. It is preferable that the refrigerant is taken from.

  In the fuel cell cooling system according to the present invention, the refrigerant circulation pump arranged in series in the cooling flow path and the gas inlet and the gas outlet for supplying the oxidizing gas to the cathode side of the fuel cell are arranged in parallel. A humidifier, and the humidifier is disposed downstream of the refrigerant circulation pump and upstream of the fuel cell stack, and the air conditioning heat exchanger is disposed downstream of the radiator and upstream of the refrigerant circulation pump. It is preferred that a refrigerant be incorporated.

  In the fuel cell cooling system according to the present invention, the refrigerant circulation pump arranged in series in the cooling flow path and the gas inlet and the gas outlet for supplying the oxidizing gas to the cathode side of the fuel cell are arranged in parallel. It is preferable to include a humidifier and a diversion position switching means for switching the position of the inlet and outlet of the diversion flow path for diverting the refrigerant from the cooling flow path to the second heat exchanger.

  In the fuel cell cooling system according to the present invention, the refrigerant circulation pump arranged in series in the cooling flow path and the gas inlet and the gas outlet for supplying the oxidizing gas to the cathode side of the fuel cell are arranged in parallel. It is preferable to include a humidifier and a diversion position switching means for switching the position of the inlet and outlet of the diversion flow path for diverting the refrigerant from the cooling flow path to the air conditioning heat exchanger.

  Further, in the fuel cell cooling system according to the present invention, a refrigerant circulation pump arranged in series with the cooling flow path, and a diversion flow path through which the refrigerant diverted from the cooling flow path flows, and an air conditioning heat exchanger and a heater And a second refrigerant circulation pump, an air-conditioning diversion channel, a circulation channel arranged in parallel with the air-conditioning diversion channel, and an air-conditioning diversion for switching the connection relationship between the cooling channel and the circulation channel for the air-conditioning diversion channel And switching means.

  Further, in the fuel cell cooling system according to the present invention, the air conditioning diversion switching means is connected so that the air conditioning diversion flow path and the circulation flow path become a closed loop, and each is separated from the cooling flow path, and a closed loop connection state, It is preferable to switch the connection relationship between a direct connection state in which the air-conditioning branch flow path and the cooling flow path are directly connected and separated from the circulation flow path.

  Further, in the fuel cell cooling system according to the present invention, the second circulation pump is a pump having a low flow rate operation efficiency better than that of the first circulation pump, and further, according to the operating state of the fuel cell, The means for controlling the operation and the operation of the second circulation pump in association with each other, and when the fuel cell is in a low-load operation state, the operation of the first circulation pump is stopped and the refrigerant is supplied to the fuel cell stack by the second circulation pump. It is preferable to provide a pump operation control means for circulating the gas.

  The fuel cell cooling system according to the present invention further includes a refrigerant circulation pump arranged in series in the cooling flow path, and the second heat exchanger is a refrigerant upstream from the radiator and from the downstream side of the fuel cell stack. It is preferable that the refrigerant be returned to the downstream side of the radiator and the upstream side of the fuel cell stack.

  The fuel cell cooling system according to the present invention further includes a refrigerant circulation pump arranged in series in the cooling flow path, and the second heat exchanger is located downstream of the refrigerant circulation pump and upstream of the fuel cell stack. It is preferable that the refrigerant is taken from.

  The fuel cell cooling system according to the present invention further includes a refrigerant circulation pump arranged in series in the cooling flow path, and the air conditioning heat exchanger is located downstream from the refrigerant circulation pump and from the upstream side of the fuel cell stack. It is preferred that a refrigerant be incorporated.

  Further, the fuel cell cooling system according to the present invention includes a refrigerant circulation pump arranged in series in the cooling flow path, and the air conditioning heat exchanger has a refrigerant from the upstream side of the radiator on the downstream side of the fuel cell stack. Preferably incorporated.

  According to at least one of the above-described configurations, the cooling flow path for circulating the refrigerant between the fuel cell stack and the radiator, and the cooling flow path is provided in parallel to the fuel cell stack with respect to the cooling flow path, and the refrigerant in the cooling flow path is divided. 2 heat exchangers. Further, according to at least one of the above-described configurations, a cooling flow path for circulating the refrigerant between the fuel cell stack and the radiator, and a second heat exchanger that is provided in parallel to the radiator and to which the refrigerant in the cooling flow path is branched . Therefore, the refrigerant is shared between the cooling of the fuel cell stack and the second heat exchanger. Since the main cooling flow path passing through the radiator and the diverted cooling flow path passing through the second heat exchanger are in parallel, by controlling the diversion ratio, the fuel cell stack cooling system and the second heat flow path are controlled. Cooperative control with the exchange system becomes possible. The diversion ratio can be controlled by setting or changing the flow resistance ratio between the main flow cooling flow and the diversion cooling flow, or setting or changing the installation position of the refrigerant supply pump.

  Further, since the second heat exchanger also serves as a cooling device for the gas compressor for supplying the oxidizing gas, the cooling system for the fuel cell stack and the cooling system for the oxidizing gas supply gas compressor are integrated. It can be coordinated.

  In addition, an air conditioner heat exchanger for air conditioning in the passenger compartment is provided in parallel with the fuel cell stack, and the refrigerant in the cooling channel is diverted, so that the cooling system of the fuel cell stack and the air conditioning system in the passenger compartment Can be integrated and controlled. In addition, the cooling system of the fuel cell stack, the cooling system of the gas compressor for supplying the oxidizing gas, and the air conditioning system in the passenger compartment can be integrated and controlled in an integrated manner.

  Further, in the fuel cell cooling system, the refrigerant diversion ratio varies depending on the configuration of the cooling system, particularly the position of the circulation pump. Therefore, the configuration of the cooling system can be selected from the viewpoint of how to split the fuel cell stack, the second heat exchanger, and the air conditioning heat exchanger.

  According to at least one of the above configurations, the humidifier is disposed on the upstream side of the fuel cell stack on the downstream side of the refrigerant circulation pump, and the second heat exchanger is on the downstream side of the radiator and on the upstream side of the refrigerant circulation pump. Refrigerant is introduced. In this configuration, (the amount of refrigerant flowing through the radiator) + (the amount of refrigerant flowing through the second heat exchanger) = the total amount of refrigerant = (the amount of refrigerant flowing through the fuel cell stack) + (the amount of refrigerant flowing through the humidifier) If the amount of refrigerant flowing through the humidifier is small, a considerably large amount of refrigerant can be supplied to the fuel cell stack.

  Further, according to at least one of the above configurations, the humidifier is disposed on the downstream side of the refrigerant circulation pump and on the upstream side of the fuel cell stack, and the second heat exchanger is disposed on the downstream side of the refrigerant circulation pump and the humidifier. Refrigerant is taken from the upstream side. In this configuration, (the amount of refrigerant flowing through the radiator) = total refrigerant amount = (the amount of refrigerant flowing through the second heat exchanger) + (the amount of refrigerant flowing through the fuel cell stack) + (the amount of refrigerant flowing through the humidifier). Can supply the largest amount of refrigerant.

  Further, according to at least one of the above configurations, the humidifier is disposed upstream of the refrigerant circulation pump and downstream of the radiator, and the second heat exchanger is downstream of the radiator and upstream of the humidifier. The refrigerant is taken from. In this configuration, (the amount of refrigerant flowing through the radiator) + (the amount of refrigerant flowing through the second heat exchanger) + (the amount of refrigerant flowing through the humidifier) = total refrigerant amount = (the amount of refrigerant flowing through the fuel cell stack). The largest amount of refrigerant can be supplied to the battery stack.

  Further, according to at least one of the above configurations, the refrigerant circulation pump is arranged in series with the cooling flow path, and the humidifier is arranged downstream of the refrigerant circulation pump and upstream of the fuel cell stack, and the air conditioning heat exchanger The refrigerant is taken in from the downstream side of the humidifier and the upstream side of the fuel cell stack. In this configuration, (amount of refrigerant flowing through the radiator) + (amount of refrigerant flowing through the second heat exchanger) = total refrigerant amount = (amount of refrigerant flowing through the humidifier) + (amount of refrigerant flowing through the fuel cell stack) + (air conditioning heat exchange) Therefore, the refrigerant can be supplied to the air conditioning heat exchanger while supplying an appropriate amount of refrigerant to the fuel cell stack.

  Further, according to at least one of the above configurations, the refrigerant circulation pump is arranged in series with the cooling flow path, and the humidifier is arranged downstream of the refrigerant circulation pump and upstream of the fuel cell stack, and the air conditioning heat exchanger The refrigerant is taken in from the downstream side of the radiator and the upstream side of the refrigerant circulation pump. In this configuration, (amount of refrigerant flowing through the radiator) + (amount of refrigerant flowing through the air conditioning heat exchanger) + (amount of refrigerant flowing through the second heat exchanger) = total refrigerant amount = (amount of refrigerant flowing through the humidifier) + (fuel cell) Therefore, the refrigerant can be supplied to other elements while supplying a considerable amount of refrigerant to the fuel cell stack.

  In addition, since there is provided a diversion position switching means for switching the position of the inlet and outlet of the diversion flow path for diverting the refrigerant from the cooling flow path to the second heat exchanger, for example, according to the operating state of the fuel cell stack By switching the position, it is possible to supply the fuel cell stack with an amount of refrigerant corresponding to its operating state.

  In addition, since there is a diversion position switching means for switching the position of the inlet and outlet of the diversion flow path for diverting the refrigerant from the cooling flow path to the air conditioning heat exchanger, the diversion position can be switched according to the vehicle interior temperature or the like. Thus, it is possible to supply the air conditioning heat exchanger with the amount of refrigerant corresponding to the temperature in the passenger compartment.

  Further, when the refrigerant is diverted from the cooling channel to the air conditioning heat exchanger, the air conditioning diversion channel including the air conditioning heat exchanger, the heater, and the second refrigerant circulation pump, and the circulation arranged in parallel with the air conditioning diversion channel A flow path is provided, and the connection relation between the cooling flow path and the circulation flow path is switched for the air-conditioning branch flow path. As a result, the connection relationship between the air conditioning shunt flow channel and the cooling flow channel related to cooling of the fuel cell stack can be switched both cooperatively and independently, and the degree of freedom of the cooling system is increased. For example, when the fuel cell stack is at a low temperature, it is possible to prevent the unwarmed refrigerant from flowing into the air-conditioning branch flow path and supply the warm refrigerant to the air-conditioning heat exchanger after the fuel cell stack is warmed.

  In addition, the air-conditioning branch flow path can be separated from the cooling flow path and can be connected to the circulation flow path so as to form a closed loop. Can be connected directly. In the former case, the refrigerant can be circulated only between the air conditioning heat exchanger and the heater, and the vehicle interior can be warmed independently. In the latter case, the refrigerant can be shared in cooperation with the refrigerant flow path.

  Further, the second circulation pump has a lower flow rate operation efficiency than the first circulation pump, and when the fuel cell is in a low load operation state, the operation of the first circulation pump is stopped, and the fuel cell is operated by the second circulation pump. Circulate refrigerant through the stack. When the fuel cell stack is in a low-load operation state, there is no need for cooling by a radiator, and it is often sufficient to circulate the refrigerant at a low flow rate. In this case, by using the second circulation pump, less power is required and the fuel efficiency of the entire system can be improved.

  According to at least one of the above-described configurations, the second heat exchanger receives refrigerant from the upstream side of the radiator and from the downstream side of the fuel cell stack, and enters the downstream side of the radiator and upstream of the fuel cell stack. To return. In this configuration, (the amount of refrigerant flowing through the radiator) + (the amount of refrigerant flowing through the second heat exchanger) = the total amount of refrigerant = (the amount of refrigerant flowing through the fuel cell stack), so a considerably large amount of refrigerant is added to the fuel cell stack. Can supply.

  In addition, due to at least one of the above configurations, the second heat exchanger takes in the refrigerant from the downstream side of the refrigerant circulation pump and from the upstream side of the fuel cell stack. In this configuration, (amount of refrigerant flowing through the radiator) = total refrigerant amount = (amount of refrigerant flowing through the second heat exchanger) + (amount of refrigerant flowing through the fuel cell stack), so that the largest amount of refrigerant can be supplied to the radiator. .

  In addition, due to at least one of the above configurations, the refrigerant circulation pump is arranged in series with the cooling flow path, and the air conditioning heat exchanger takes in the refrigerant from the downstream side of the refrigerant circulation pump and from the upstream side of the fuel cell stack. In this configuration, (the amount of refrigerant flowing through the radiator) + (the amount of refrigerant flowing through the second heat exchanger) = the total amount of refrigerant = (the amount of refrigerant flowing through the fuel cell stack) + (the amount of refrigerant flowing through the air conditioning heat exchanger). The refrigerant can be supplied to the air conditioning heat exchanger while supplying an appropriate amount of refrigerant to the fuel cell stack.

  Further, due to at least one of the above-described configurations, the refrigerant circulation pump is arranged in series with the cooling flow path, and the air conditioning heat exchanger takes in the refrigerant from the downstream side of the fuel cell stack and the upstream side of the radiator. In this configuration, (amount of refrigerant flowing through the radiator) + (amount of refrigerant flowing through the air conditioning heat exchanger) + (amount of refrigerant flowing through the second heat exchanger) = total refrigerant amount = (amount of refrigerant flowing through the fuel cell stack) While supplying a considerable amount of refrigerant to the fuel cell stack, the refrigerant can be supplied to other elements.

  As described above, according to the fuel cell cooling system of the present invention, cooperative control between the cooling system of the fuel cell stack and the other heat exchange system is possible.

1 is a configuration diagram of a fuel cell operation system to which a fuel cell cooling system according to an embodiment of the present invention is applied. It is a figure which shows the structure of the cooling system of the fuel cell of embodiment which concerns on this invention. It is a figure which shows other embodiment. It is a figure which shows other embodiment. It is a figure which shows embodiment about cooperative control with an air-conditioning heat exchanger. It is a figure which shows other embodiment about cooperative control with an air-conditioning heat exchanger. It is a figure which shows another embodiment about cooperative control with an air-conditioning heat exchanger. FIG. 8 is a diagram showing an example of the connection state of the air-conditioning shunt flow path in the embodiment of FIG. In the embodiment of FIG. 7, it is a figure which shows the other example of the connection state of an air-conditioning shunt flow path. FIG. 8 is a diagram for explaining the operation of the circulation pump in the embodiment of FIG. 7. It is a figure which shows the structure of the cooling system of the fuel cell of another embodiment. It is a figure which shows other embodiment. It is a figure which shows other embodiment. It is a figure which shows another embodiment about cooperative control with an air-conditioning heat exchanger. It is a figure which shows other embodiment about cooperative control with an air-conditioning heat exchanger. It is a figure which shows other embodiment about cooperative control with an air-conditioning heat exchanger. In embodiment of FIG. 16, it is a figure which shows the example of the connection state of an air-conditioning shunt flow path. In embodiment of FIG. 16, it is a figure which shows the other example of the connection state of an air-conditioning shunt flow path. FIG. 17 is a diagram for explaining the operation of the circulation pump in the embodiment of FIG. 16.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Since the fuel cell cooling system is a cooling system applied to the fuel cell operating system, the configuration of the fuel cell operating system will be described first, and then the cooling system will be described. FIG. 1 is a configuration diagram of a fuel cell operating system 10 to which a fuel cell cooling system is applied. The fuel cell operation system 10 includes a system main body 20 and a control unit 70 that controls each element of the system main body 20 as a whole system.

  The system body 20 includes a fuel cell body called a fuel cell stack 22 in which a plurality of fuel cells are stacked, elements for supplying hydrogen gas disposed on the anode side of the fuel cell stack 22, and a cathode side. Each element for air supply is configured.

  The anode-side hydrogen gas source 24 is a tank that supplies hydrogen as a fuel gas. The hydrogen gas source 24 is connected to the regulator 26. The regulator 26 has a function of adjusting the gas from the hydrogen gas source 24 to an appropriate pressure and flow rate. A pressure gauge 28 provided at the output port of the regulator 26 is a measuring instrument that detects the supply hydrogen pressure. The output port of the regulator 26 is connected to the anode side inlet of the fuel cell stack 22, and the fuel gas adjusted to an appropriate pressure and flow rate is supplied to the fuel cell stack 22.

  The gas discharged from the anode side outlet of the fuel cell stack 22 consumes hydrogen during power generation, resulting in a low hydrogen concentration, and nitrogen gas, which is a component of the cathode side air, permeates through the MEA (Mebrane Electrode Assembly). As a result, the impurity gas concentration is high. The reaction product water also permeates through the MEA.

  The flow divider 32 connected to the anode side outlet of the fuel cell stack 22 is for flowing the impurity gas concentration of the exhaust gas from the anode side outlet to the diluter 64 through the exhaust valve 34. The exhaust gas at this time is a hydrogen gas containing reaction product water in addition to nitrogen. The circulation booster 30 provided between the shunt 32 and the anode side inlet further has a function of increasing the hydrogen partial pressure of the gas returning from the anode side outlet and returning it to the anode side inlet for reuse. It has a hydrogen pump.

  The cathode side oxygen supply source 40 can actually use the atmosphere. The atmosphere as the oxygen supply source 40 is supplied to the cathode side through the filter 42. The flow meter 44 provided after the filter 42 is a flow meter that detects the total supply flow rate from the oxygen supply source 40. The thermometer 46 provided after the filter 42 has a function of detecting the temperature of the gas from the oxygen supply source 40.

  The air compressor (ACP) 48 is a gas booster that compresses the supply gas by the motor 50 to increase its pressure. In addition, the ACP (48) has a function of providing a predetermined amount of supply gas by changing the rotation speed (the number of rotations per minute) under the control of the control unit. That is, when the required flow rate of the supply gas is large, the rotational speed of the motor 50 is increased. Conversely, when the required flow rate of the supply gas is small, the rotational speed of the motor 50 is decreased. The ACP power consumption detector 52 is a measuring instrument having a function of detecting the power consumption of the ACP (48), specifically, the power consumption of the motor 50. The power consumption of the motor 50 increases as the rotational speed increases, and the power consumption decreases as the rotational speed decreases. Therefore, the power consumption is closely related to the rotational speed of the motor or the supply gas flow rate.

  Thus, since oxygen-containing air is supplied to the cathode side of the fuel cell stack 22 under the control of the control unit 70 by the ACP (48), the oxygen-containing air is hereinafter referred to as cathode-side supply gas, Alternatively, it will be simply referred to as supply gas. Therefore, the elements from the oxygen supply source 40 to the ACP (48) can be called an oxygen supply device.

  The humidifier 54 has a function of appropriately moistening the supply gas and efficiently performing the fuel cell reaction in the fuel cell stack 22. The supply gas appropriately moistened by the humidifier 54 is supplied to the cathode side inlet of the fuel cell stack 22 and exhausted from the cathode side outlet. At this time, water as a reaction product is also discharged together with the exhaust. Since the fuel cell stack 22 is heated to a high temperature by the reaction, the discharged water is water vapor, and this water vapor is supplied to the humidifier 54 to moderately moisten the supply gas. Thus, the humidifier 54 has a function of appropriately supplying water vapor to the supply gas, and a gas exchanger using a so-called hollow fiber can be used. That is, the humidifier 54 is configured to be able to exchange gas between the flow path through which the gas from the ACP (48) flows and the flow path through which the water vapor flows. For example, the inner flow path of the hollow fiber is used as a flow path for the supply gas from the ACP (48), and the outer flow path of the hollow fiber is used as water vapor from the cathode side outlet of the fuel cell stack 22, thereby The supply gas to the cathode side inlet can be appropriately moistened.

  Here, the flow path connecting the oxygen supply device and the cathode side inlet of the fuel cell stack 22 can be referred to as an inlet side flow path. Correspondingly, the flow path connected from the cathode side outlet of the fuel cell stack 22 to the exhaust side can be called an outlet side flow path.

  The pressure gauge 56 provided at the cathode side outlet of the outlet side channel has a function of detecting the gas pressure at the cathode side outlet. The pressure regulating valve 60 provided in the outlet side flow path is also called a back pressure valve, and is a valve having a function of adjusting the gas pressure of the cathode side outlet and adjusting the flow rate of the supply gas to the fuel cell stack 22, for example, butterfly A valve that can adjust the effective opening of the flow path, such as a valve, can be used.

  Since the output port of the pressure regulating valve 60 is connected to the humidifier 54 described above, the gas that has exited the pressure regulating valve 60 supplies water vapor to the humidifier 54 and then returns to enter the diluter 64 and then to the outside. Discharged.

  The bypass valve 62 is a valve provided in a bypass channel that is connected in parallel with the fuel cell stack 22 by connecting the inlet channel and the outlet channel, and is mainly air for diluting the hydrogen concentration in the exhaust gas. Is supplied to the diluter 64. That is, by opening the bypass valve 62, the supply gas from the ACP (48) is separated from the component that flows to the fuel cell stack 22, and does not flow through the fuel cell stack 22, but passes through the bypass flow path to the diluter 64. Can be supplied to. As the bypass valve 62, a valve having the same configuration as the exhaust bypass valve used for engine exhaust gas dilution can be used. Such an exhaust bypass valve is sometimes called an EGR valve.

  The diluter 64 collects the waste water containing hydrogen from the exhaust valve 34 on the anode side and the exhaust gas containing hydrogen leaked through the MEA due to the water vapor on the cathode side, and discharges it to the outside as an appropriate hydrogen concentration. It is a buffer container. When the hydrogen concentration exceeds an appropriate concentration, by opening the bypass valve 62, a more appropriate dilution can be performed using the supply gas provided without going through the fuel cell stack 22.

  The control unit 70 controls the above-described elements of the system main body unit 20 as a whole system, and is sometimes called a so-called fuel cell CPU. For example, the control unit 70 has a function of performing coordinated control of the pressure regulating valve and the bypass valve according to the operating state of the fuel cell. In addition, in order to appropriately maintain the temperature of the fuel cell stack 22, the temperature of the ACP 48, the temperature of the supply gas on the cathode side, etc. according to the operating state of the fuel cell, it has a function of controlling a cooling system described later. These functions can be realized by software, specifically, by executing a corresponding fuel cell operation program, fuel cell cooling program, and the like. Some of these functions can also be realized by hardware.

  In such a fuel cell operation system 10, the fuel cell stack 22 generates heat due to a reaction between the fuel gas and the supply gas. The ACP (48) also generates heat from the motor 50 and the like during its operation. Further, the temperature of the supply gas supplied to the cathode side of the fuel cell stack 22 is preferably appropriate. When the fuel cell operation system 10 is mounted on a vehicle, an air conditioning system is provided for air conditioning in the vehicle interior. For example, when the vehicle interior is cold, the waste heat of the fuel cell stack 22 is used. If possible, it is desirable to use it to bring the interior of the vehicle to an appropriate temperature in a short time. As described above, it is necessary to adjust the temperature of the elements constituting the fuel cell operation system 10 such as cooling, and a fuel cell cooling system is provided for this purpose.

  In the following description, a cooling flow path for cooling the fuel cell stack with a radiator will be referred to as a main cooling flow path, and a cooling flow path for diverting refrigerant in parallel to the main cooling flow path will be described as a diversion cooling flow path. Then, the heat exchanger provided in the shunt cooling flow path will be described for cooling the ACP (48) and used for vehicle interior air conditioning. The former considers the radiator as the first heat exchanger and calls it the second heat exchanger, and the latter calls the air conditioning heat exchanger. In this case, the second heat exchanger is integrated as a cooling system by exchanging heat with an intercooler for independently cooling the conventional ACP (48) with the diverted refrigerant. However, as a matter of course, the intercooler may be maintained as an independent cooling system as usual, and the second heat exchanger may be used for cooling other elements.

  FIG. 2 is a diagram showing the configuration of the fuel cell cooling system 100. Here, a cooling system on the cathode side in the fuel cell operation system is shown. The flow path 80 of the supply gas that enters the fuel cell stack 22 from the ACP (48) through the humidifier 54 and exits the fuel cell stack 22 is shown by a thin line, whereas the flow path of the refrigerant flows by a thick line. It is shown. The fuel cell cooling system 100 is provided with a main cooling channel 102 and a branch cooling channel 104 that is arranged in parallel to the main cooling channel 102 and divides the same refrigerant as the channels through which the refrigerant flows. As the refrigerant, LLC (Long Life Coolant) mainly composed of water can be used.

  The main cooling channel 102 includes a radiator 110 having an air cooling fan, a heater 112 for heating, a three-way valve 114 for appropriately diverting the refrigerant to the heater 112, and a circulation pump (WP) for circulating the refrigerant. ) 130 is arranged. The refrigerant flowing through the main cooling flow path 102 circulates between the radiator 110 and the fuel cell stack 22, the heat of the fuel cell stack 22 whose temperature has risen is carried away by the refrigerant, cooled by the radiator 110, and again the fuel cell stack 22. It has a function to return to The humidifier 54 is arranged in parallel to the gas inlet and the gas outlet for supplying the oxidizing gas to the cathode side of the fuel cell stack 22 as described above, and the cooling is also performed by the main cooling channel 102.

  The diversion cooling channel 104 is arranged in parallel with the main cooling channel 102. Then, the refrigerant in the main cooling flow path 102 is taken in from the supply side flow path where the refrigerant flows from the radiator 110 toward the fuel cell stack 22, and the refrigerant in the main cooling flow path 102 returns from the fuel cell stack 22 toward the radiator 110. The refrigerant diverted to the discharge-side flow path is returned. The shunt cooling flow path 104 reaches the second heat exchanger 120 via the casing of the motor 50 of the ACP (48) and the like, and is supplied from the ACP (48) to the humidifier 54 and the fuel cell stack 22. Heat exchange is also performed on the compressed supply gas flow path 80 and then returned to the main cooling flow path 102. Therefore, the second heat exchanger 120 has a function of removing heat from the motor 50 of the ACP (48) and adjusting the temperature of the supply gas. Conventionally, this function is executed by an independent cooling system called an intercooler. However, in the configuration of FIG. 2, this conventional intercooler function is shared with the cooling system from the radiator 110 to the fuel cell stack 22 with the refrigerant. Integrated.

  Here, the circulation pump 130 is provided in the supply-side flow path of the main cooling flow path 102, and is provided on the upstream side of the humidifier 54 and downstream of the refrigerant intake and diversion position of the diversion cooling flow path 104. Referring to FIG. 2, the humidifier 54 is disposed downstream of the circulation pump 130 and upstream of the fuel cell stack 22, and the second heat exchanger 120 is downstream of the radiator 110 and is connected to the circulation pump. The refrigerant is taken in from the upstream side of 130. That is, there are the radiator 110 and the second heat exchanger 120 as the refrigerant flows upstream of the circulation pump 130, and the humidifier 54 and the fuel cell stack 22 as the refrigerant flows downstream of the circulation pump 130. is there.

  Therefore, in this configuration, (amount of refrigerant flowing through the radiator 110) + (amount of refrigerant flowing through the second heat exchanger 120) = total refrigerant amount = (amount of refrigerant flowing through the fuel cell stack 22) + (amount of refrigerant flowing through the humidifier 54) Therefore, if the amount of refrigerant flowing through the humidifier 54 is small, a considerably large amount of refrigerant can be supplied to the fuel cell stack 22. The ratio of the amount of refrigerant flowing through the humidifier 54 and the amount of refrigerant flowing through the fuel cell stack 22 can be determined by the ratio of these flow path resistances. For example, when the amount of refrigerant flowing through the humidifier 54: the amount of refrigerant flowing through the fuel cell stack 22 = 2: 98, 98% of the total amount of refrigerant can be supplied to the fuel cell stack 22. As a result, when the temperature of the fuel cell stack 22 is too high, the heat can be quickly carried out to the radiator 110 side. Further, the ratio of (the amount of refrigerant flowing through the radiator 110) and (the amount of refrigerant flowing through the second heat exchanger 120) can also be determined by the ratio of these flow path resistances, or the control for controlling the flow dividing ratio. The amount of refrigerant flowing through these can be determined using valves, and the radiator 110 and the second heat exchanger 120 can be operated cooperatively.

  Further, since the shunt cooling flow path 104 is provided in parallel with the main cooling flow path 102, the difference between the temperature of the refrigerant discharged from the second heat exchanger 120 and the temperature of the refrigerant discharged from the fuel cell stack 22 is determined. Can be reduced. The former defines the supply gas temperature on the supply gas inlet side of the humidifier 54, and the latter defines the temperature of the supply gas outlet of the humidifier 54. Thus, the temperature difference between the gas inlets of the humidifier 54 is determined. Even when a hollow fiber structure is used, damage due to temperature differences at both ends can be suppressed.

  In the fuel cell cooling system, the manner in which the refrigerant is distributed can be changed by the manner in which the shunt cooling passage is divided from the main cooling passage and the arrangement manner of the circulation pump 130. FIG. 3 is a diagram showing a configuration of a cooling system 140 for a fuel cell that can send the largest amount of refrigerant to the radiator 110. Elements similar to those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the fuel cell cooling system 140 of FIG. 3, the circulation pump 130 is provided in the supply-side flow path of the main cooling flow path 102, and is located downstream of the radiator 110 and upstream of the refrigerant intake and diversion position of the diversion cooling flow path 144. Is provided. Referring to FIG. 3, the humidifier 54 is disposed downstream of the circulation pump 130 and upstream of the fuel cell stack 22, and the second heat exchanger 120 is downstream of the radiator 110 and is connected to the circulation pump. The refrigerant is taken in from the upstream side of 130. That is, only the radiator 110 exists as the refrigerant flows on the upstream side of the circulation pump 130, and the second heat exchanger 120, the humidifier 54, and the fuel cell stack 22 indicate that the refrigerant flows on the downstream side of the circulation pump 130. There is.

  Therefore, in this configuration, (amount of refrigerant flowing through the radiator 110) = total refrigerant amount = (amount of refrigerant flowing through the second heat exchanger 120) + (amount of refrigerant flowing through the fuel cell stack 22) + (amount of refrigerant flowing through the humidifier 54) Therefore, (the amount of refrigerant flowing through the radiator 110) can be maximized. Thereby, for example, when the temperature difference between the supply gas inlet side and the outlet side of the fuel cell stack 22 is large, the maximum refrigerant is sent from the fuel cell stack 22 to the radiator 110 to effectively reduce the temperature difference. Can do.

  FIG. 4 is a diagram showing a configuration of a fuel cell cooling system 150 that can send the largest amount of refrigerant to the fuel cell stack 22. Elements similar to those in FIGS. 2 and 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the fuel cell cooling system 150 of FIG. 4, the circulation pump 130 is provided in the supply-side flow path of the main cooling flow path 102, and is connected to the refrigerant intake branch position of the shunt cooling flow path 154 and the downstream side of the humidifier 54. It is provided immediately upstream of the battery stack 22. Referring to FIG. 4, the humidifier 54 is disposed on the upstream side of the circulation pump 130 and on the downstream side of the radiator 110, and the second heat exchanger 120 is disposed on the downstream side of the radiator 110 and the humidifier. The refrigerant is taken in from the upstream side of 54. That is, there are the radiator 110, the second heat exchanger 120, and the humidifier 54 as the refrigerant flows on the upstream side of the circulation pump 130, and only the fuel cell stack 22 as the refrigerant flows on the downstream side of the circulation pump 130. There is.

  Therefore, in this configuration, (amount of refrigerant flowing through the radiator 110) + (amount of refrigerant flowing through the second heat exchanger 120) + (amount of refrigerant flowing through the humidifier 54) = total refrigerant amount = (amount of refrigerant flowing through the fuel cell stack 22) Therefore, (the amount of refrigerant flowing through the fuel cell stack 22) can be maximized. Thereby, the maximum refrigerant can be sent to the fuel cell stack 22 and the heat can be effectively discharged from the fuel cell stack 22.

  In the fuel cell cooling system, the refrigerant can be diverted from the main cooling channel to the air conditioning heat exchanger for air conditioning in the passenger compartment. FIG. 5 is a diagram showing a configuration of a fuel cell cooling system 160 for diverting refrigerant to the air conditioning heat exchanger. Elements similar to those in FIG. 2 and the like are denoted by the same reference numerals, and detailed description thereof is omitted.

  In addition to the cooling system including the shunt cooling flow path 104 and the second heat exchanger 120 described in FIG. 2, the fuel cell cooling system 160 of FIG. 5 further includes an air conditioning heat exchanger for air conditioning of the vehicle interior 162. 170 is provided with an air conditioning diverted cooling flow path 164 for diverting the refrigerant from the main cooling flow path 102. The air conditioning diversion cooling channel 164 is provided with a heater 166 provided as necessary, and a shut valve 168 that controls opening and closing of the diversion to the air conditioning diversion cooling channel 164.

  The refrigerant intake branching position for the air conditioning heat exchanger 170 in the main cooling channel 102 is immediately before the refrigerant inlet to the fuel cell stack 22. Referring to FIG. 5, the humidifier 54 is disposed downstream of the circulation pump 130 and upstream of the fuel cell stack 22, and the air conditioning heat exchanger 170 is downstream of the humidifier 54. A refrigerant is taken in from the upstream side of the fuel cell stack 22. When the shut valve 168 is opened, the taken-in branch refrigerant is supplied to the air conditioning heat exchanger 170 via the heater 166 and returned to the main cooling flow path 102 again. This refrigerant return position is immediately after the refrigerant outlet from the fuel cell stack 22.

  In this configuration, (amount of refrigerant flowing through the radiator 110) + (amount of refrigerant flowing through the second heat exchanger 120) = total refrigerant amount = (amount of refrigerant flowing through the humidifier 54) + (amount of refrigerant flowing through the fuel cell stack 22) + Therefore, the refrigerant can be supplied to the air conditioning heat exchanger while supplying an appropriate amount of refrigerant to the fuel cell stack 22.

  That is, with this configuration, the refrigerant that is heated by the operation of the fuel cell stack 22 and is maintained at an appropriate temperature by the radiator 110 and circulated can be supplied to the air conditioning heat exchanger 170, and a special independent air conditioning system is provided. In addition, the passenger compartment 162 can be warmed to provide an appropriate air conditioning environment. If necessary, the heater 112 or the heater 166 can be used. Further, when the fuel cell stack 22 is not sufficiently warmed, the shut valve 168 is closed so that a cold refrigerant cannot be sent to the air conditioning heat exchanger 170.

  Thus, the power of the circulation pump 130 can be reduced by controlling the shut valve 168 to open only when the passenger compartment needs to be heated. In addition, as shown in FIG. 6, a heater 166 for auxiliary heating in the passenger compartment is provided in the system of the air conditioning heat exchanger 170 to cool the normal fuel cell stack 22 in which the shut valve 168 is closed. During operation, no pressure loss occurs in the heater 166, and fuel consumption can be reduced.

  As described above, by making the refrigerant common to the cooling system of the fuel cell stack 22 and the cabin air conditioning system, and controlling the opening and closing of the shut valve 168 according to the temperature of the fuel cell stack 22 and the cabin temperature, The cooling system of the fuel cell stack 22 and the passenger compartment air conditioning system can be integrated under cooperative control. In FIG. 6, it has been described as including the shunt cooling flow path 104 including the second heat exchanger 120 and performing coordinated control of the radiator 110, the second heat exchanger 120, and the air conditioning heat exchanger 170. The two heat exchangers 120 may be omitted and coordinated control may be performed between the radiator 110 and the air conditioning heat exchanger 170.

  In the cooling system including the air conditioning heat exchanger, the manner in which the refrigerant is distributed can be changed according to the manner in which the air conditioning shunt cooling passage is divided from the main cooling passage and the arrangement manner of the circulation pump 130. FIG. 6 is a diagram showing a configuration of a fuel cell cooling system 180 in which a refrigerant intake diversion position for the air conditioning heat exchanger 170 in the main cooling flow path 102 is provided immediately after the radiator 110 to divert the refrigerant. Elements similar to those in FIG. 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the fuel cell cooling system 180 of FIG. 6, the refrigerant intake branch position for the air conditioning heat exchanger 170 in the main cooling flow path 102 is immediately before the refrigerant inlet of the radiator 110 to the fuel cell stack 22. Referring to FIG. 6, the humidifier 54 is disposed downstream of the circulation pump 130 and upstream of the fuel cell stack 22, and the air-conditioning heat exchanger 170 is downstream of the radiator 110 and circulates. A refrigerant is taken in from the upstream side of the pump 130. When the shut valve 168 is opened, the taken-in branch refrigerant is supplied to the air conditioning heat exchanger 170 via the heater 166 and returned to the main cooling flow path 102 again. This refrigerant return position is immediately after the refrigerant outlet from the fuel cell stack 22.

  In this configuration, (the amount of refrigerant flowing through the radiator 110) + (the amount of refrigerant flowing through the air conditioning heat exchanger 170) + (the amount of refrigerant flowing through the second heat exchanger 120) = total refrigerant amount = (the amount of refrigerant flowing through the humidifier 54) Since + (the amount of refrigerant flowing through the fuel cell stack 22), the refrigerant can be supplied to other elements while supplying a considerable amount of refrigerant to the fuel cell stack 22.

  That is, according to this configuration, the refrigerant that is warmed by the operation of the fuel cell stack 22 and maintained at an appropriate temperature by the radiator 110 and circulated can be supplied to the air conditioning heat exchanger 170, and a special independent air conditioning system can be provided. Without being provided, the passenger compartment 162 can be warmed to provide an appropriate air-conditioning environment. If necessary, a heater 166 can be used. Further, when the fuel cell stack 22 is not sufficiently warmed, the shut valve 168 is closed so that a cold refrigerant cannot be sent to the air conditioning heat exchanger 170. Since a considerable amount of refrigerant can be supplied to the fuel cell stack 22, heat can be quickly carried out from the fuel cell stack 22.

  As described above, in the fuel cell cooling system, a mode in which the shunt cooling channel for the second heat exchanger and the shunt cooling channel for air conditioning for the air conditioning heat exchanger are shunted from the main cooling channel, and circulation Depending on the arrangement of the pumps, the manner of refrigerant distribution can be variously changed. Therefore, by switching between the branch position from the main cooling flow path and the position where the circulation pump is arranged, the cooling of the fuel cell stack and the second heat exchanger are performed in accordance with the operating state of the fuel cell operating system 10 or the operating state of the vehicle. It is possible to cooperatively control the heat exchange between the ACP (48) and the supply gas, the air conditioning in the passenger compartment by the air conditioning heat exchanger, etc., and supply a refrigerant amount suitable for each.

  For example, by providing a diversion position switching means for switching the position on the cooling flow path between the inlet and the outlet of the diversion flow path for diverting the refrigerant from the cooling flow path to the second heat exchanger, and depending on the operating state of the fuel cell stack By switching the branch position, the amount of refrigerant corresponding to the operating state can be supplied to the fuel cell stack.

  In addition, since there is a diversion position switching means for switching the position of the inlet and outlet of the diversion flow path for diverting the refrigerant from the cooling flow path to the air conditioning heat exchanger, the diversion position can be switched according to the vehicle interior temperature or the like. Thus, it is possible to supply the air conditioning heat exchanger with the amount of refrigerant corresponding to the temperature in the passenger compartment.

  7 devise the configuration of the cooling flow path for air conditioning, and the refrigerant flowing to the air conditioning heat exchanger 170 can be shared in common with the main cooling flow path 102, or only for the air conditioning heat exchanger 170. It is a figure which shows the structure of the cooling system 200 of the fuel cell which can also be used independently. Elements common to FIG. 5 and the like are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the fuel cell cooling system 200 of FIG. 7, the air conditioning shunt cooling flow path 202 is composed of three elements. That is, the input / output flow path 204 through which the refrigerant is taken back from the main cooling flow path 102, the air conditioning diversion flow path 206 through which the refrigerant flows through the air conditioning heat exchanger 170, and the air conditioning diversion flow path 206 are arranged in parallel. The circulation flow path 208 constitutes the entire air conditioning shunt cooling flow path 202.

  As shown in FIG. 7, the three-way valves 210 and 212 are provided at connection points of three flow paths, that is, an input / output flow path 204, an air-conditioning branch flow path 206, and a circulation flow path 208. Therefore, the connection relationship among the input / output flow path 204, the air-conditioning branch flow path 206, and the circulation flow path 208 is switched by the two three-way valves 210 and 212. In that sense, the two three-way valves 210 and 212 are means for switching the connection relation between the input / output flow path 204 connected to the main cooling flow path 102 and the circulation flow path 208 with respect to the air conditioning shunt flow path 206. Some aspects of switching will be described later.

  A refrigerant circulation pump different from the circulation pump 130 provided in the main cooling flow path 102 is provided in the air-conditioning branch flow path 206. This pump can be called the second circulation pump 220 in distinction from the circulation pump 130. In the air conditioning branch flow path 206, the second circulation pump 220, the heater 222, and the air conditioning heat exchanger 170 are arranged in series. In FIG. 7, the three-way valve 210, the second circulation pump 220, the heater 222, the air conditioning heat exchanger 170, and the three-way valve 212 are arranged in this order. Other orders may also be used, and in some cases, a switching valve and the like may be arranged in parallel.

  The second circulation pump 220 is a refrigerant circulation pump that is smaller than the circulation pump 130 in the main cooling flow path 102. The circulation pump 130 in the main cooling flow path 102 can circulate the refrigerant through the refrigerant flow path including the radiator 110, the humidifier 54, and the fuel cell stack 22 and quickly exchange heat to maintain the temperature of the refrigerant appropriately. Thus, a pump having a capacity capable of operating sufficiently even at a large flow rate is used. On the other hand, since the second circulation pump 220 is mainly for circulating the refrigerant around the air conditioning heat exchanger 170, a small capacity pump can be used. Since the second circulation pump 220 is small, the operation efficiency is good at a low flow rate as compared with the circulation pump 130 in the main cooling flow path 102. Further, the second circulation pump 220 is preferably one that can pass the refrigerant even when it is not actuated. By doing so, the efficiency of the refrigerant flow can be prevented from being lowered even when the second circulation pump 220 is not operated.

  The input / output flow path 204 is a refrigerant flow path from the main cooling flow path 102 to the three-way valves 210 and 212, and in this sense, can also be considered as a part of the main cooling flow path 102. The circulation flow path 208 forms a loop flow path by being connected in parallel with the air conditioning diversion flow path 206.

  Next, switching of the cooling flow path by the three-way valves 210 and 212 will be described. The switching operation of the three-way valves 210 and 212 is performed according to the operating state of the fuel cell stack 22 by a cooling control unit (not shown). Note that the control unit 70 of the fuel cell operation system 10 can also serve as the cooling control unit. FIG. 8 is a diagram illustrating a state in which the air-conditioning diversion channel 206 and the circulation channel 208 are connected in a closed loop by switching the three-way valves 210 and 212. At this time, the input / output flow path 204 is separated from the closed loop flow path. Note that the three-way valves 210 and 212 are not shown in FIG. Specifically, the three-way valve 210 is operated so as to connect one side of the air-conditioning diversion channel 206 and one side of the circulation channel 208, and the three-way valve 212 circulates with the other side of the air-conditioning diversion channel 206. By operating to connect the other side of the flow path 208, this closed loop flow path is formed.

  By forming the closed loop channel, the refrigerant can be circulated in the closed loop channel by the second circulation pump 220 independently of the main cooling channel 102. That is, the refrigerant can be circulated between the heater 222 and the air conditioning heat exchanger 170. This connection state is preferably performed when the fuel cell stack 22 is in an operating state where the temperature is still low. As a result, it is possible to prevent the refrigerant that has not been sufficiently heated by the fuel cell stack 22 and remains cold from being fed into the air conditioning heat exchanger 170. Then, by operating the heater 222 and the second circulation pump 220, the refrigerant in the closed loop flow path can be sufficiently warmed and supplied to the air conditioning heat exchanger 170. Thereby, the passenger compartment 162 can be efficiently and quickly warmed.

  FIG. 9 is a diagram illustrating a state in which the circulation flow path 208 is separated by switching the three-way valves 210 and 212 and the input / output flow path 204 and the air-conditioning branch flow path 206 are connected. Also here, as in FIG. 8, the three-way valves 210 and 212 are not shown for easy understanding of the state of the flow path. Specifically, the three-way valve 210 is operated so as to connect one side of the input / output flow path 204 connected to the refrigerant intake side of the main cooling flow path 102 and one side of the air-conditioning branch flow path 206. The three-way valve 212 is operated so as to connect the other side of the air-conditioning diversion channel 206 and the other side of the input / output channel 204 connected to the refrigerant return side of the main cooling channel 102. Thus, the circulation flow path 208 is separated, the input / output flow path 204 and the air conditioning shunt flow path 206 are directly connected, and the air conditioning shunt flow path 206 is parallel to the main cooling flow path 102 flowing through the fuel cell stack 22. Can be arranged.

  This connection method is basically the same as the configuration of FIG. That is, the air-conditioning shunt cooling flow path 202 shares the refrigerant with the main cooling flow path 102 and performs so-called cooperative control. Therefore, the three-way valves 210 and 212 have a function of switching the air-conditioning branch flow path 206 to the main cooling flow path 102 in a cooperative control connection or an independent control connection. In this cooperative control connection, the operation drive of the second circulation pump 220 is stopped. As described above, even in this case, since the refrigerant can freely pass through the second circulation pump 220, the efficiency of the refrigerant flow in the air-conditioning branch flow path 206 does not decrease.

  As described with reference to FIG. 5, the cooperative control is performed when the refrigerant is circulated while being heated by the operation of the fuel cell stack 22 and maintained at an appropriate temperature by the radiator 110. Therefore, the connection method of the closed loop flow path in FIG. 8 and the connection method of the cooperative control are switched according to the operating state of the fuel cell stack 22. For example, when the fuel cell stack 22 is not yet warmed, the heater 222 and the second circulation pump 220 are operated as a method of connecting the closed loop flow path in FIG. 8 to increase the temperature of the refrigerant supplied to the air conditioning heat exchanger 170, When the fuel cell stack 22 is warmed and the temperature of the refrigerant in the main cooling flow path 102 rises, the direct connection method shown in FIG. 9 is switched to stop the operation of the heater 222. Thereby, the power required for warming up the passenger compartment 162 can be reduced, and fuel consumption can be improved.

  The switching timing between the closed loop flow path connection method of FIG. 8 and the direct connection method of FIG. 9 is when the refrigerant temperature of the fuel cell stack 22, for example, the cooling water temperature reaches a predetermined target water temperature. Can do. Alternatively, in order to further improve the fuel consumption, switching may be performed at an earlier timing, for example, when heat exchange is possible and the temperature reaches 50 ° C. close to the target water temperature.

  FIG. 10 shows the operation of the second circulation pump 220 and the operation of the circulation pump 130 in the main cooling flow path 102 when the connection method of FIG. 9, that is, when the air-conditioning branch flow path 206 and the main cooling flow path 102 are directly connected. It is a figure which shows a mode when stopping. Switching between the operation of the circulation pump 130 and the second circulation pump 220 in the main cooling flow path 102 is performed according to the operating state of the fuel cell stack 22 by a cooling control unit (not shown). When the circulation pump 130 of the main cooling channel 102 does not operate, the refrigerant does not circulate in the main cooling channel 102. Under the conditions, when the second circulation pump 220 is operated in the connected state of FIG. 9, the refrigerant is the second circulation pump 220 -the heater 222 -the air conditioning heat exchanger 170 -the fuel cell stack 22 -the second circulation pump 220. In the closed loop.

  The operation state described with reference to FIG. 10 is preferably used when the fuel cell stack 22 is in a low load operation state such as an idle operation state or an intermittent operation state. When the fuel cell stack 22 is in a low load operation state, the amount of heat generated is small, so that cooling by the radiator 110 is often unnecessary. Therefore, the operation of the large-capacity circulation pump 130 in the main cooling flow path 102 is stopped, and the refrigerant is circulated by the small second circulation pump 220 instead. The second circulation pump 220 is more efficient in operation than the large-capacity circulation pump 130 when the flow rate is low. That is, it is possible to efficiently circulate the refrigerant with less electric power than the large-capacity circulation pump 130, and to improve the fuel efficiency at a low load. When the fuel cell stack 22 has a medium load or a high load, as described with reference to FIG. 9, the operation drive of the second circulation pump 220 is stopped, and the refrigerant is supplied only by the operation drive of the circulation pump 130 in the main cooling flow path 102. Circulate. As a result, the electric power required to drive the second circulation pump 220 can be reduced, and the fuel efficiency at medium and high loads can be improved.

  In addition, when the refrigerant is warmed in the connection state of the closed loop flow path in FIG. 8 and the passenger compartment 162 is warmed by the air conditioning heat exchanger 170, and the air conditioning of the passenger compartment 162 is turned off by the user, the heater 222 is operated. In this state, the direct connection state shown in FIG. 9 or 10 is switched. When the air conditioning is turned off, the fan or the like that sends warm air from the air conditioning heat exchanger 170 to the vehicle interior 162 is turned off. However, since the heater 222 is operating, warm refrigerant is supplied to the fuel cell stack 22 and the fuel cell stack 22 is moved early. Can warm up.

  5 to 10, it is preferable to insulate the refrigerant flow path including the air conditioning heat exchanger 170 by an appropriate heat insulating means. For example, the refrigerant channel pipe can be covered with a suitable heat insulating material. Thereby, at the time of starting of the fuel cell operation system, heat exchange in the air conditioning heat exchanger 170 can be efficiently performed, and the passenger compartment 162 can be warmed up early. Therefore, the passenger compartment 162 can be warmed with little electric power and the like, and the fuel efficiency can be improved.

  In the above description, the main cooling flow path 102 has been described as passing through the humidifier 54, but it may be configured not to pass through the humidifier 54. In addition, the refrigerant intake and return ports for the second heat exchanger 120 in the main cooling channel 102 are configured opposite to the above description, and the refrigerant flows from the motor 50 toward the second heat exchanger 120. It can also be. Further, the refrigerant intake and return ports for the air-conditioning heat exchanger 170 in the main cooling flow path 102 can be configured to be the reverse of the above description. Hereinafter, such a configuration will be described. In the following, the same elements as those in FIGS. 1 to 10 are denoted by the same reference numerals, and detailed description thereof is omitted.

  FIG. 11 is a diagram showing a configuration of a fuel cell cooling system 300. The fuel cell cooling system 300 is different from the fuel cell cooling system 100 described in FIG. 2 in that the main cooling flow path 102 does not pass through the humidifier 54 and the second heat exchanger in the main cooling flow path 102. The refrigerant inlet for 120 and the return outlet are reversed. Here, as described with reference to FIG. 2, the fuel cell cooling system 300 is arranged in parallel with the main cooling flow path 102 and the main cooling flow path 102 as a flow path for the refrigerant. A shunt cooling flow path 104 for shunting is provided.

  The main cooling channel 102 includes a radiator 110 having an air cooling fan, a heater 112 for heating, a three-way valve 114 for appropriately diverting the refrigerant to the heater 112, and a circulation pump (WP) for circulating the refrigerant. ) 130 is arranged. The refrigerant flowing through the main cooling flow path 102 circulates between the radiator 110 and the fuel cell stack 22, the heat of the fuel cell stack 22 whose temperature has risen is carried away by the refrigerant, cooled by the radiator 110, and again the fuel cell stack 22. It has a function to return to The humidifier 54 is arranged in parallel with the gas inlet and the gas outlet for supplying the oxidizing gas to the cathode side of the fuel cell stack 22 as described above. And the humidifier 54 is not cooled by the refrigerant in the main cooling channel 102.

  The ion exchanger 132 in FIG. 11 is a device having a function of removing cooling water ions as a refrigerant. This is because ions dissolve in the cooling water from the elements constituting the circulation path of the cooling water, so that the ions are removed and the resistance of the cooling water as a refrigerant is kept high. As shown in FIG. 11, the ion exchanger 132 is arranged in parallel with the main cooling flow path 102, but may be arranged in series with the main cooling flow path 102 in some cases. The ion exchanger 132 is preferably provided with ion detection means for detecting the ion concentration of the cooling water.

  The diversion cooling channel 104 is arranged in parallel with the main cooling channel 102. Then, the refrigerant is taken in from the discharge-side flow path where the refrigerant in the main cooling flow path 102 is returned from the fuel cell stack 22 toward the radiator 110, and the refrigerant in the main cooling flow path 102 is directed from the radiator 110 toward the fuel cell stack 22. It returns toward the flowing supply side flow path. The shunt cooling flow path 104 reaches the second heat exchanger 120 of the ACP (48), where the compressed supply gas flow path 80 supplied from the ACP (48) to the fuel cell stack 22 via the humidifier 54. Then, the heat exchange is performed and then returned to the main cooling channel 102. Therefore, the second heat exchanger 120 has a function of adjusting the temperature of the supply gas. Conventionally, this function is executed by an independent cooling system called an intercooler. However, in the configuration of FIG. 11 as in FIG. 2, the function of this conventional intercooler is changed to a cooling system from the radiator 110 to the fuel cell stack 22. The refrigerant is shared and integrated.

  Here, the circulation pump 130 is provided in the supply side flow path of the main cooling flow path 102, and is provided in the downstream side of the refrigerant return branch position of the branch flow cooling flow path 104. Referring to FIG. 11, the second heat exchanger 120 receives refrigerant from the upstream side of the radiator 110 and the downstream side of the fuel cell stack 22. That is, there are the radiator 110 and the second heat exchanger 120 as the refrigerant flows on the upstream side of the circulation pump 130, and the fuel cell stack 22 as the refrigerant flows on the downstream side of the circulation pump 130.

  Therefore, in this configuration, (the amount of refrigerant flowing through the radiator 110) + (the amount of refrigerant flowing through the second heat exchanger 120) = the total amount of refrigerant = (the amount of refrigerant flowing through the fuel cell stack 22). A considerable amount of refrigerant can be supplied. As a result, when the temperature of the fuel cell stack 22 is too high, the heat can be quickly carried out to the radiator 110 side. Further, the ratio of (the amount of refrigerant flowing through the radiator 110) and (the amount of refrigerant flowing through the second heat exchanger 120) can also be determined by the ratio of these flow path resistances, or the control for controlling the flow dividing ratio. The amount of refrigerant flowing through these can be determined using valves, and the radiator 110 and the second heat exchanger 120 can be operated cooperatively.

  Further, since the shunt cooling flow path 104 is provided in parallel with the main cooling flow path 102, the difference between the temperature of the refrigerant discharged from the second heat exchanger 120 and the temperature of the refrigerant discharged from the fuel cell stack 22 is determined. Can be reduced. The former defines the supply gas temperature on the supply gas inlet side of the humidifier 54, and the latter defines the temperature of the supply gas outlet of the humidifier 54. Thus, the temperature difference between the gas inlets of the humidifier 54 is determined. Even when a hollow fiber structure is used, damage due to temperature differences at both ends can be suppressed.

  In the fuel cell cooling system, the manner in which the refrigerant is distributed can be changed by the manner in which the shunt cooling passage is divided from the main cooling passage and the arrangement manner of the circulation pump 130. FIG. 12 is a diagram showing a configuration of a fuel cell cooling system 340 that can send the largest amount of refrigerant to the radiator 110.

  In the fuel cell cooling system 340 of FIG. 12, the circulation pump 130 is provided in the supply-side flow path of the main cooling flow path 102, on the downstream side of the radiator 110, on the upstream side of the refrigerant return branch position of the shunt cooling flow path 144. Is provided. Referring to FIG. 12, the second heat exchanger 120 receives refrigerant from the downstream side of the radiator 110, the downstream side of the circulation pump 130, and the downstream side of the fuel cell stack 22. That is, only the radiator 110 is the refrigerant that flows on the upstream side of the circulation pump 130, and the second heat exchanger 120 and the fuel cell stack 22 are the one that the refrigerant flows on the downstream side of the circulation pump 130.

  Therefore, in this configuration, (the amount of refrigerant flowing through the radiator 110) = the total amount of refrigerant = (the amount of refrigerant flowing through the second heat exchanger 120) + (the amount of refrigerant flowing through the fuel cell stack 22), so (flowing through the radiator 110) Refrigerant amount) can be maximized. Thereby, for example, when the temperature difference between the supply gas inlet side and the outlet side of the fuel cell stack 22 is large, the maximum refrigerant is sent from the fuel cell stack 22 to the radiator 110 to effectively reduce the temperature difference. Can do.

  FIG. 13 is a diagram showing the configuration of a fuel cell cooling system 350 that can send the largest amount of refrigerant to the fuel cell stack 22.

  In the fuel cell cooling system 350 of FIG. 13, the circulation pump 130 is provided in the supply side flow path of the main cooling flow path 102, and downstream of the refrigerant return branch position of the shunt cooling flow path 154, Immediately upstream. Referring to FIG. 13, the second heat exchanger 120 receives refrigerant from the upstream side of the radiator 110 and the downstream side of the fuel cell stack 22. That is, there are the radiator 110 and the second heat exchanger 120 as the refrigerant flows on the upstream side of the circulation pump 130, and only the fuel cell stack 22 as the refrigerant flows on the downstream side of the circulation pump 130.

  Therefore, in this configuration, (the amount of refrigerant flowing through the radiator 110) + (the amount of refrigerant flowing through the second heat exchanger 120) = the total amount of refrigerant = (the amount of refrigerant flowing through the fuel cell stack 22). The amount of refrigerant flowing through the Thereby, the maximum refrigerant can be sent to the fuel cell stack 22 and the heat can be effectively discharged from the fuel cell stack 22.

  In the fuel cell cooling system, the refrigerant can be diverted from the main cooling channel to the air conditioning heat exchanger for air conditioning in the passenger compartment. FIG. 14 is a diagram showing a configuration of a fuel cell cooling system 360 for diverting the refrigerant to the air conditioning heat exchanger.

  In addition to the cooling system including the shunt cooling flow path 104 and the second heat exchanger 120 described in FIG. 11, the fuel cell cooling system 360 of FIG. 14 further includes an air conditioning heat exchanger for air conditioning of the vehicle interior 162. 170 is provided with an air conditioning diverted cooling flow path 164 for diverting the refrigerant from the main cooling flow path 102. The air conditioning diversion cooling channel 164 is provided with a heater 166 provided as necessary, and a shut valve 168 that controls opening and closing of the diversion to the air conditioning diversion cooling channel 164.

  The refrigerant intake branching position for the air conditioning heat exchanger 170 in the main cooling channel 102 is immediately before the refrigerant inlet to the fuel cell stack 22. Referring to FIG. 14, the air conditioning heat exchanger 170 takes refrigerant from the upstream side of the fuel cell stack 22. When the shut valve 168 is opened, the taken-in branch refrigerant is supplied to the air conditioning heat exchanger 170 via the heater 166 and returned to the main cooling flow path 102 again. This refrigerant return position is immediately after the refrigerant outlet from the fuel cell stack 22.

  In this configuration, (amount of refrigerant flowing through the radiator 110) + (amount of refrigerant flowing through the second heat exchanger 120) = total refrigerant amount = (amount of refrigerant flowing through the fuel cell stack 22) + (amount of refrigerant flowing through the air conditioning heat exchanger 170) Therefore, the refrigerant can be supplied to the air conditioning heat exchanger while supplying an appropriate amount of refrigerant to the fuel cell stack 22.

  That is, with this configuration, the refrigerant that is heated by the operation of the fuel cell stack 22 and is maintained at an appropriate temperature by the radiator 110 and circulated can be supplied to the air conditioning heat exchanger 170, and a special independent air conditioning system is provided. In addition, the passenger compartment 162 can be warmed to provide an appropriate air conditioning environment. If necessary, the heater 112 or the heater 166 can be used. Further, when the fuel cell stack 22 is not sufficiently warmed, the shut valve 168 is closed so that a cold refrigerant cannot be sent to the air conditioning heat exchanger 170.

  Thus, the power of the circulation pump 130 can be reduced by controlling the shut valve 168 to open only when the passenger compartment needs to be heated. Further, as shown in FIG. 14, a heater 166 for auxiliary heating in the passenger compartment is provided in the system of the air conditioning heat exchanger 170 to cool the normal fuel cell stack 22 in which the shut valve 168 is closed. During operation, no pressure loss occurs in the heater 166, and fuel consumption can be reduced.

  As described above, by making the refrigerant common to the cooling system of the fuel cell stack 22 and the cabin air conditioning system, and controlling the opening and closing of the shut valve 168 according to the temperature of the fuel cell stack 22 and the cabin temperature, The cooling system of the fuel cell stack 22 and the passenger compartment air conditioning system can be integrated under cooperative control. In FIG. 14, it has been described as including the shunt cooling flow path 104 including the second heat exchanger 120 and performing coordinated control of the radiator 110, the second heat exchanger 120, and the air conditioning heat exchanger 170. The two heat exchangers 120 may be omitted and coordinated control may be performed between the radiator 110 and the air conditioning heat exchanger 170.

  In the cooling system including the air conditioning heat exchanger, the manner in which the refrigerant is distributed can be changed according to the manner in which the air conditioning shunt cooling passage is divided from the main cooling passage and the arrangement manner of the circulation pump 130. FIG. 15 is a diagram showing a configuration of a fuel cell cooling system 380 in which a refrigerant intake diversion position for the air conditioning heat exchanger 170 in the main cooling flow path 102 is provided immediately after the radiator 110 to divert the refrigerant.

  In the fuel cell cooling system 380 of FIG. 15, the refrigerant intake branching position for the air conditioning heat exchanger 170 in the main cooling channel 102 is downstream of the fuel cell stack 22 and upstream of the radiator 110. Referring to FIG. 15, the air conditioning heat exchanger 170 takes in the refrigerant from the upstream side of the radiator 110 immediately after the downstream outlet of the fuel cell stack 22. When the shut valve 168 is opened, the taken-in branch refrigerant is supplied to the air conditioning heat exchanger 170 and the heater 166 and returned to the main cooling flow channel 102 again. This refrigerant return position is downstream of the radiator 110 and upstream of the circulation pump 130.

  In this configuration, (amount of refrigerant flowing through the radiator 110) + (amount of refrigerant flowing through the air conditioning heat exchanger 170) + (amount of refrigerant flowing through the second heat exchanger 120) = total amount of refrigerant = (amount of refrigerant flowing through the fuel cell stack 22) Therefore, the refrigerant can be supplied to the other elements while supplying a considerable amount of the refrigerant to the fuel cell stack 22.

  That is, according to this configuration, the refrigerant that is warmed by the operation of the fuel cell stack 22 and maintained at an appropriate temperature by the radiator 110 and circulated can be supplied to the air conditioning heat exchanger 170, and a special independent air conditioning system can be provided. Without being provided, the passenger compartment 162 can be warmed to provide an appropriate air-conditioning environment. If necessary, a heater 166 can be used. Further, when the fuel cell stack 22 is not sufficiently warmed, the shut valve 168 is closed so that a cold refrigerant cannot be sent to the air conditioning heat exchanger 170. Since a considerable amount of refrigerant can be supplied to the fuel cell stack 22, heat can be quickly carried out from the fuel cell stack 22.

  As described above, also in the fuel cell cooling system in which the refrigerant from the main cooling channel does not pass through the humidifier 54, the shunt cooling channel and the air conditioning heat exchange for the second heat exchanger from the main cooling channel. The manner in which the refrigerant is distributed can be variously changed according to the manner in which the air-conditioning shunt cooling flow path for the cooler is shunted and the arrangement manner of the circulation pump. Therefore, by switching between the branch position from the main cooling flow path and the position where the circulation pump is arranged, the cooling of the fuel cell stack and the second heat exchanger are performed in accordance with the operating state of the fuel cell operating system 10 or the operating state of the vehicle. It is possible to cooperatively control the heat exchange between the ACP (48) and the supply gas, the air conditioning in the passenger compartment by the air conditioning heat exchanger, etc., and supply a refrigerant amount suitable for each.

  For example, by providing a diversion position switching means for switching the positions of the inlet and outlet of the diversion flow path for diverting the refrigerant from the cooling flow path to the second heat exchanger on the cooling flow path, the flow is diverted according to the operating state of the fuel cell stack. By switching the position, it is possible to supply the fuel cell stack with an amount of refrigerant corresponding to its operating state.

  In addition, since there is a diversion position switching means for switching the position of the inlet and outlet of the diversion flow path for diverting the refrigerant from the cooling flow path to the air conditioning heat exchanger, the diversion position can be switched according to the vehicle interior temperature or the like. Thus, it is possible to supply the air conditioning heat exchanger with the amount of refrigerant corresponding to the temperature in the passenger compartment.

  FIG. 16 devises the configuration of the cooling flow path for air conditioning, and the refrigerant flowing to the air conditioning heat exchanger 170 can be shared with the main cooling path 102 in a coordinated manner, or only for the air conditioning heat exchanger 170. It is a figure which shows the structure of the cooling system 400 of the fuel cell which can also be used independently.

  In the fuel cell cooling system 400 of FIG. 16, the air-conditioning shunt cooling flow path 202 includes three elements. That is, the input / output flow path 204 through which the refrigerant is taken back from the main cooling flow path 102, the air conditioning diversion flow path 206 through which the refrigerant flows through the air conditioning heat exchanger 170, and the air conditioning diversion flow path 206 are arranged in parallel. The circulation flow path 208 constitutes the entire air conditioning shunt cooling flow path 202.

  As shown in FIG. 16, a three-way valve 212 is provided at a connection point of three flow paths, that is, an input / output flow path 204, an air conditioning diversion flow path 206, and a circulation flow path 208. Therefore, the connection relationship among the input / output flow path 204, the air-conditioning branch flow path 206, and the circulation flow path 208 is switched by the three-way valve 212. In that sense, the three-way valve 212 is means for switching the connection relationship between the air-conditioning branch flow path 206 and the input / output flow path 204 connected to the main cooling flow path 102 and the circulation flow path 208. Some aspects of switching will be described later.

  A refrigerant circulation pump different from the circulation pump 130 provided in the main cooling flow path 102 is provided in the air-conditioning branch flow path 206. This pump can be called the second circulation pump 220 in distinction from the circulation pump 130. In the air conditioning branch flow path 206, the second circulation pump 220, the heater 222, and the air conditioning heat exchanger 170 are arranged in series. In FIG. 16, the three-way valve 212, the second circulation pump 220, the heater 222, and the air conditioning heat exchanger 170 are arranged in this order, but the arrangement order of the elements between the three-way valves 212 is other than this order. Depending on circumstances, it may be arranged in parallel including a switching valve or the like.

  The second circulation pump 220 is a refrigerant circulation pump that is smaller than the circulation pump 130 in the main cooling flow path 102. The circulation pump 130 in the main cooling flow path 102 can circulate the refrigerant through the refrigerant flow path including the radiator 110, the humidifier 54, and the fuel cell stack 22 and quickly exchange heat to maintain the temperature of the refrigerant appropriately. Thus, a pump having a capacity capable of operating sufficiently even at a large flow rate is used. On the other hand, since the second circulation pump 220 is mainly for circulating the refrigerant around the air conditioning heat exchanger 170, a small capacity pump can be used. Since the second circulation pump 220 is small, the operation efficiency is good at a low flow rate as compared with the circulation pump 130 in the main cooling flow path 102. Further, the second circulation pump 220 is preferably one that can pass the refrigerant even when it is not actuated. By doing so, the efficiency of the refrigerant flow can be prevented from being lowered even when the second circulation pump 220 is not operated.

  The input / output flow path 204 is a refrigerant flow path from the main cooling flow path 102 to the three-way valve 212, and in that sense, can be considered as a part of the main cooling flow path 102. The circulation flow path 208 forms a loop flow path by being connected in parallel with the air conditioning diversion flow path 206.

  Next, switching of the cooling flow path by the three-way valve 212 will be described. The switching operation of the three-way valve 212 is performed according to the operating state of the fuel cell stack 22 by a cooling control unit (not shown). Note that the control unit 70 of the fuel cell operation system 10 can also serve as the cooling control unit. FIG. 17 is a diagram illustrating a state in which the air-conditioning diversion channel 206 and the circulation channel 208 are connected in a closed loop by switching the three-way valve 212. At this time, the input / output flow path 204 is separated from the closed loop flow path. Note that the three-way valve 212 is indicated by a broken line in FIG. Specifically, the three-way valve 212 is operated so as to connect one side of the air-conditioning diversion channel 206 and one side of the circulation channel 208, thereby forming this closed loop channel.

  By forming the closed loop channel, the refrigerant can be circulated in the closed loop channel by the second circulation pump 220 independently of the main cooling channel 102. That is, the refrigerant can be circulated between the heater 222 and the air conditioning heat exchanger 170. This connection state is preferably performed when the fuel cell stack 22 is in an operating state where the temperature is still low. As a result, it is possible to prevent the refrigerant that has not been sufficiently heated by the fuel cell stack 22 and remains cold from being fed into the air conditioning heat exchanger 170. Then, by operating the heater 222 and the second circulation pump 220, the refrigerant in the closed loop flow path can be sufficiently warmed and supplied to the air conditioning heat exchanger 170. Thereby, the passenger compartment 162 can be efficiently and quickly warmed.

  FIG. 18 is a diagram illustrating a state in which the circulation flow path 208 is separated by switching the three-way valve 212 and the input / output flow path 204 and the air conditioning diversion flow path 206 are connected. Here, as in FIG. 17, the three-way valve 212 is indicated by a broken line in order to make the state of the flow path easy to understand. Specifically, the three-way valve 212 is operated so as to connect one side of the input / output flow path 204 connected to the refrigerant intake side of the main cooling flow path 102 and one side of the air-conditioning diversion flow path 206. The Thus, the circulation flow path 208 is separated, the input / output flow path 204 and the air conditioning shunt flow path 206 are directly connected, and the air conditioning shunt flow path 206 is parallel to the main cooling flow path 102 flowing through the fuel cell stack 22. Can be arranged.

  This connection method is basically the same as the configuration shown in FIGS. That is, the air-conditioning shunt cooling flow path 202 shares the refrigerant with the main cooling flow path 102 and performs so-called cooperative control. Therefore, the three-way valve 212 has a function of switching the air-conditioning branch flow path 206 to the main cooling flow path 102 in a cooperative control connection or an independent control connection. In this cooperative control connection, the operation drive of the second circulation pump 220 is stopped. As described above, even in this case, since the refrigerant can freely pass through the second circulation pump 220, the efficiency of the refrigerant flow in the air-conditioning branch flow path 206 does not decrease.

  The coordinated control is performed when the refrigerant is circulated while being heated by the operation of the fuel cell stack 22 and maintained at an appropriate temperature by the radiator 110, as described with reference to FIGS. Therefore, the connection method of the closed loop flow path and the connection method of the cooperative control in FIG. 17 are switched according to the operating state of the fuel cell stack 22. For example, when the fuel cell stack 22 is not yet warmed, the heater 222 and the second circulation pump 220 are operated to increase the temperature of the refrigerant supplied to the air conditioning heat exchanger 170 as a method of connecting the closed loop flow path in FIG. When the temperature of the refrigerant in the main cooling flow path 102 rises as the fuel cell stack 22 warms up, the operation is switched to the direct connection method shown in FIG. Thereby, the power required for warming up the passenger compartment 162 can be reduced, and fuel consumption can be improved.

  The switching timing between the closed loop flow path connection method of FIG. 17 and the direct connection method of FIG. 18 is set when the temperature of the refrigerant of the fuel cell stack 22, for example, the cooling water temperature reaches a predetermined target water temperature. Can do. Alternatively, in order to further improve the fuel consumption, switching may be performed at an earlier timing, for example, when heat exchange is possible and the temperature reaches 50 ° C. close to the target water temperature.

  FIG. 19 is a modification of the connection method of FIG. Here, the air conditioning diversion channel 206 is returned to the upstream side of the fuel cell stack 22 in the main cooling channel 102. The three-way valve 212 is operated so as to connect one side of the input / output channel 204 connected to the refrigerant intake side of the main cooling channel 102 and one side of the air-conditioning branch channel 206. As a result, the circulation flow path 208 is separated, and the input / output flow path 204 and the air-conditioning branch flow path 206 are directly connected. However, the second circulation pump 220 is operated there, and the circulation pump 130 of the main cooling flow path 102 is connected. The operation of is stopped. Switching between the operation of the circulation pump 130 and the second circulation pump 220 in the main cooling flow path 102 is performed according to the operating state of the fuel cell stack 22 by a cooling control unit (not shown).

  When the circulation pump 130 of the main cooling channel 102 does not operate, the refrigerant does not circulate in the main cooling channel 102. Under the conditions, when the second circulation pump 220 is operated in the connected state of FIG. 19, the refrigerant is the second circulation pump 220 -the heater 222 -the air conditioning heat exchanger 170 -the fuel cell stack 22 -the second circulation pump 220. In the closed loop.

  The operation state described with reference to FIG. 19 is preferably used when the fuel cell stack 22 is in a low load operation state such as an idle operation state or an intermittent operation state. When the fuel cell stack 22 is in a low load operation state, the amount of heat generated is small, so that cooling by the radiator 110 is often unnecessary. Therefore, the operation of the large-capacity circulation pump 130 in the main cooling flow path 102 is stopped, and the refrigerant is circulated by the small second circulation pump 220 instead. The second circulation pump 220 is more efficient in operation than the large-capacity circulation pump 130 when the flow rate is low. That is, it is possible to efficiently circulate the refrigerant with less electric power than the large-capacity circulation pump 130, and to improve the fuel efficiency at a low load. When the fuel cell stack 22 has a medium load or a high load, as described with reference to FIG. 9, the operation drive of the second circulation pump 220 is stopped, and the refrigerant is supplied only by the operation drive of the circulation pump 130 in the main cooling flow path 102. Circulate. As a result, the electric power required to drive the second circulation pump 220 can be reduced, and the fuel efficiency at medium and high loads can be improved.

  In addition, when the refrigerant is warmed in the connection state of the closed loop flow path in FIG. 17 and the passenger compartment 162 is warmed by the air conditioning heat exchanger 170 and then the air conditioning of the passenger compartment 162 is turned off by the user, the heater 222 is operated. In this state, the direct connection state shown in FIG. 18 or 19 is switched. When the air conditioning is turned off, the fan or the like that sends warm air from the air conditioning heat exchanger 170 to the vehicle interior 162 is turned off. However, since the heater 222 is operating, warm refrigerant is supplied to the fuel cell stack 22 and the fuel cell stack 22 is moved early. Can warm up.

10 Fuel Cell Operation System, 20 System Main Body, 22 Fuel Cell Stack, 24
Hydrogen gas source, 26 regulator, 28 pressure gauge, 30 circulation booster, 32 shunt, 34 exhaust valve, 40 oxygen supply source, 42 filter, 44 flow meter, 46 thermometer, 48 ACP, 50 motor, 52 ACP power consumption Detector, 54 Humidifier, 56 Pressure gauge, 60 Pressure regulating valve, 62 Bypass valve, 64 Diluter, 70 Controller, 80 Supply gas flow path, 100, 140, 150, 160, 180, 200, 300, 340, 350, 360, 380, 400 Fuel cell cooling system, 102 main cooling flow path, 104, 144, 154 shunt cooling flow path, 110 radiator, 112, 166, 222 heater, 114 three-way valve, 120 second heat exchanger, 130 Circulation Pump, 132 Ion Exchanger, 162 Cabin, 164, 202 Air Conditioning Shunt Cooling Channel, 168 Shut Valve, 17 0 air conditioning heat exchanger, 204 input / output flow path, 206 air conditioning shunt flow path, 208 circulation flow path, 210, 212 three-way valve, 220 second circulation pump.

A fuel cell cooling system according to the present invention is a fuel cell cooling system in which a fuel gas is supplied to an anode side and an oxidizing gas is supplied to a cathode side to generate electric power by an electrochemical reaction, and includes a fuel cell stack and a radiator. A cooling channel that circulates the refrigerant between them, a second heat exchanger that is provided in parallel to the fuel cell stack and the radiator with respect to the cooling channel, and is arranged in series with the cooling channel. A refrigerant circulation pump and a control unit, and the control unit switches the branching position with respect to the second heat exchanger in the cooling flow path and the arrangement position of the circulation pump, so that the refrigerant is upstream of the circulation pump. There are a radiator and a second heat exchanger that flow, and a system that has a fuel cell stack as a refrigerant flows on the downstream side of the circulation pump and an upstream side of the circulation pump. There is only a radiator as the refrigerant flows, the refrigerant flows on the downstream side of the circulation pump, the system with the second heat exchanger and the fuel cell stack, and the refrigerant flows on the upstream side of the circulation pump , A radiator and a second heat exchanger, and a system in which only the fuel cell stack has a refrigerant flowing on the downstream side of the circulation pump, and distribution of the amount of refrigerant according to the operating condition of the fuel cell by any one of It is characterized by performing .

Further, the second heat exchanger, Rukoto to adjust the temperature of the oxidizing gas exchanges heat with respect to the flow path of the compressed feed gas supplied to the fuel cell stack from the gas compressor for supplying oxidizing gas are preferred.

Further, in the fuel cell cooling system according to the present invention, the fuel cell is a vehicle fuel cell mounted on a vehicle, and an air conditioning heat exchanger for air conditioning in the passenger compartment is provided in parallel with the fuel cell stack, It is preferable that the refrigerant in the cooling flow path is divided.
Further, in the fuel cell cooling system according to the present invention, the control unit circulates by switching between a branch position for the second heat exchanger, a branch position for the air-conditioning heat exchanger, and a position of the circulation pump in the cooling flow path. There are a radiator and a second heat exchanger as the refrigerant flows on the upstream side of the pump, and there are a fuel cell stack and an air conditioning heat exchanger as the refrigerant flows on the downstream side of the circulation pump, and the upstream side of the circulation pump. The refrigerant flows through the radiator, the air-conditioning heat exchanger, and the second heat exchanger, and the fuel cell operating status depends on one of the systems in which only the fuel cell stack has the refrigerant flowing on the downstream side of the circulation pump. Or it is preferable to distribute the refrigerant | coolant amount according to the driving | running state of a vehicle.

Further, in the cooling system of a fuel cell of the invention may include a humidifier arranged in parallel to the gas inlet and gas outlet for supplying an oxidizing gas to the cathode side of the fuel cell, a humidifier, fuel cell stack It is preferable that it is arrange | positioned upstream.
Further, in the fuel cell system according to the present invention, the control unit is configured such that the refrigerant flows on the upstream side of the circulation pump by switching between the diversion position with respect to the second heat exchanger and the arrangement position of the circulation pump in the cooling flow path. , There is a radiator and a second heat exchanger, a system in which a refrigerant flows on the downstream side of the circulation pump and a humidifier and a fuel cell stack, and a refrigerant flows on the upstream side of the circulation pump, and there is only a radiator, A system in which the refrigerant flows on the downstream side of the circulation pump includes a second heat exchanger, a humidifier, and a fuel cell stack, and a refrigerant flows on the upstream side of the circulation pump in which a radiator and the second heat exchanger are provided. There is a humidifier, and there is only a fuel cell stack as a refrigerant flowing downstream of the circulation pump. It is preferable to perform the refrigerant quantity distribution according to the operating conditions of the fuel cell by one.
Further, in the fuel cell system according to the present invention, the control unit switches the flow dividing position for the second heat exchanger, the flow dividing position for the air conditioning heat exchanger, and the arrangement position of the circulation pump in the cooling flow path. There are a radiator and a second heat exchanger as the refrigerant flows on the upstream side, a humidifier, a fuel cell stack, and an air conditioning heat exchanger as the refrigerant flows on the downstream side of the circulation pump, and an upstream of the circulation pump. There are a radiator, an air conditioning heat exchanger, and a second heat exchanger as the refrigerant flows on the side, and a fuel cell depending on any one of the systems including the humidifier and the fuel cell stack as the refrigerant flows on the downstream side of the circulation pump. It is preferable to distribute the refrigerant amount according to the driving situation of the vehicle or the driving situation of the vehicle.

Further, in the fuel cell cooling system according to the present invention, the refrigerant circulation pump arranged in series with the cooling flow path as a first refrigerant circulation pump is a flow dividing flow path through which the refrigerant diverted from the cooling flow path flows. An air conditioning shunt flow path including an air conditioning heat exchanger, a heater, and a second refrigerant circulation pump, a circulation flow path arranged in parallel with the air conditioning shunt flow path, and a cooling flow path and a circulation flow path for the air conditioning shunt flow path It is preferable to include an air-conditioning / diversion switching means for switching the connection relationship.

According to at least one of the above-described configurations, the cooling flow path for circulating the refrigerant between the fuel cell stack and the radiator, and the cooling flow path is provided in parallel to the fuel cell stack with respect to the cooling flow path, and the refrigerant in the cooling flow path is divided. 2 heat exchangers. Further, according to at least one of the above-described configurations, a cooling flow path for circulating the refrigerant between the fuel cell stack and the radiator, and a second heat exchanger that is provided in parallel to the radiator and to which the refrigerant in the cooling flow path is branched . Therefore, the refrigerant is shared between the cooling of the fuel cell stack and the second heat exchanger. Since the main cooling flow path passing through the radiator and the diverted cooling flow path passing through the second heat exchanger are in parallel, by controlling the diversion ratio, the fuel cell stack cooling system and the second heat flow path are controlled. Cooperative control with the exchange system becomes possible. The diversion ratio can be controlled by setting or changing the flow resistance ratio between the main flow cooling flow and the diversion cooling flow, or setting or changing the installation position of the refrigerant supply pump.
And a control part changes a radiator and a 2nd heat exchanger as what flows a refrigerant | coolant in the upstream of a circulation pump by switching the branch position with respect to the 2nd heat exchanger in a cooling flow path, and the arrangement position of a circulation pump. There is a first method in which a fuel cell stack is provided as a refrigerant flows downstream of the circulation pump, and a radiator flows only as a refrigerant flows upstream of the circulation pump, and the refrigerant flows downstream of the circulation pump. As a thing with a 2nd system with a 2nd heat exchanger and a fuel cell stack, and a thing with which a refrigerant flows in the upstream of a circulation pump, there are a radiator and a 2nd heat exchanger, and in the downstream of a circulation pump According to the operation state of the fuel cell by any one of the third method that has only the fuel cell stack as the refrigerant flows Performing a medium amount of the distribution.
In the first method, (the amount of refrigerant flowing through the radiator) + (the amount of refrigerant flowing through the second heat exchanger) = the total amount of refrigerant = (the amount of refrigerant flowing through the fuel cell stack), so a considerable amount of refrigerant is contained in the fuel cell stack. Can supply quantity.
In the second method, (the amount of refrigerant flowing through the radiator) = the total amount of refrigerant = (the amount of refrigerant flowing through the second heat exchanger) + (the amount of refrigerant flowing through the fuel cell stack), so the largest amount of refrigerant is given to the radiator. Can supply.
In the third method, (the amount of refrigerant flowing through the radiator) + (the amount of refrigerant flowing through the second heat exchanger) = the total amount of refrigerant = (the amount of refrigerant flowing through the fuel cell stack), the most refrigerant in the fuel cell stack Can supply quantity.

Further, the second heat exchanger adjusts the temperature of the oxidizing gas by exchanging heat with respect to the flow path of the compressed supply gas supplied from the gas compressor for supplying the oxidizing gas to the fuel cell stack. The cooling system and the cooling system of the gas compressor for supplying the oxidizing gas can be integratedly controlled in a coordinated manner.

In addition, an air conditioner heat exchanger for air conditioning in the passenger compartment is provided in parallel with the fuel cell stack, and the refrigerant in the cooling channel is diverted, so that the cooling system of the fuel cell stack and the air conditioning system in the passenger compartment Can be integrated and controlled. In addition, the cooling system of the fuel cell stack, the cooling system of the gas compressor for supplying the oxidizing gas, and the air conditioning system in the passenger compartment can be integrated and controlled in an integrated manner.
Then, the control unit switches the switching position between the branching position for the second heat exchanger, the branching position for the air-conditioning heat exchanger and the arrangement position of the circulation pump in the cooling flow path, so that the refrigerant flows on the upstream side of the circulation pump. There is a radiator and a second heat exchanger, the fourth system having a fuel cell stack and an air conditioning heat exchanger as the refrigerant flows downstream of the circulation pump, and the radiator as the refrigerant flows upstream of the circulation pump. And the air conditioner heat exchanger and the second heat exchanger, and the fuel cell operating condition or the vehicle operating condition according to any one of the fifth systems in which only the fuel cell stack has a refrigerant flowing downstream of the circulation pump Distribution of the refrigerant amount according to
In the fourth system, (amount of refrigerant flowing through the radiator) + (amount of refrigerant flowing through the second heat exchanger) = total refrigerant amount = (amount of refrigerant flowing through the fuel cell stack) + (amount of refrigerant flowing through the air conditioning heat exchanger) Therefore, the refrigerant can be supplied to the air conditioning heat exchanger while supplying an appropriate amount of refrigerant to the fuel cell stack.
In the fifth method, (amount of refrigerant flowing through the radiator) + (amount of refrigerant flowing through the air conditioning heat exchanger) + (amount of refrigerant flowing through the second heat exchanger) = total refrigerant amount = (amount of refrigerant flowing through the fuel cell stack) Therefore, the largest amount of refrigerant can be supplied to the fuel cell stack.

At least one of the foregoing structures, the humidifier is arranged upstream of the fuel cell stack.
And a control part changes a radiator and a 2nd heat exchanger as what flows a refrigerant | coolant in the upstream of a circulation pump by switching the branch position with respect to the 2nd heat exchanger in a cooling flow path, and the arrangement position of a circulation pump. There is a sixth system with a humidifier and a fuel cell stack as the refrigerant flows downstream of the circulation pump, and the radiator flows only as the refrigerant flows upstream of the circulation pump. As for the flow of refrigerant, the seventh system has a second heat exchanger, a humidifier, and a fuel cell stack, and as the flow of refrigerant on the upstream side of the circulation pump, the radiator, the second heat exchanger, and the humidifier There is only one fuel cell stack in which the refrigerant flows downstream of the circulation pump. Performing refrigerant quantity distribution according to the operating conditions of the pond.
In the sixth method , (the amount of refrigerant flowing through the radiator) + (the amount of refrigerant flowing through the second heat exchanger) = the total amount of refrigerant = (the amount of refrigerant flowing through the fuel cell stack) + (the amount of refrigerant flowing through the humidifier). If the amount of refrigerant flowing through the humidifier is small, a considerably large amount of refrigerant can be supplied to the fuel cell stack.

In the seventh method , (the amount of refrigerant flowing through the radiator) = total refrigerant amount = (the amount of refrigerant flowing through the second heat exchanger) + (the amount of refrigerant flowing through the fuel cell stack) + (the amount of refrigerant flowing through the humidifier). The maximum amount of refrigerant can be supplied to the radiator.

In the eighth method , (the amount of refrigerant flowing through the radiator) + (the amount of refrigerant flowing through the second heat exchanger) + (the amount of refrigerant flowing through the humidifier) = total refrigerant amount = (the amount of refrigerant flowing through the fuel cell stack). The largest amount of refrigerant can be supplied to the fuel cell stack.

Further, the control unit switches the switching position between the branching position for the second heat exchanger, the branching position for the air conditioning heat exchanger, and the arrangement position of the circulation pump in the cooling channel, so that the refrigerant flows on the upstream side of the circulation pump. A ninth system with a humidifier, a fuel cell stack, and an air conditioning heat exchanger as a refrigerant flows downstream of the circulation pump, with a radiator and a second heat exchanger, and a refrigerant flows upstream of the circulation pump There are a radiator, an air-conditioning heat exchanger, and a second heat exchanger, and the refrigerant flows on the downstream side of the circulation pump. Or distribution of the refrigerant | coolant amount according to the driving | running state of a vehicle is performed.
In the ninth method , (amount of refrigerant flowing through the radiator) + (amount of refrigerant flowing through the second heat exchanger) = total refrigerant amount = (amount of refrigerant flowing through the humidifier) + (amount of refrigerant flowing through the fuel cell stack) + (air conditioning) Therefore, the refrigerant can be supplied to the air conditioning heat exchanger while supplying an appropriate amount of refrigerant to the fuel cell stack.

In the tenth method , (amount of refrigerant flowing through the radiator) + (amount of refrigerant flowing through the air conditioning heat exchanger) + (amount of refrigerant flowing through the second heat exchanger) = total refrigerant amount = (amount of refrigerant flowing through the humidifier) + ( Therefore, the refrigerant can be supplied to other elements while supplying a considerable amount of refrigerant to the fuel cell stack.

The diversion cooling channel 104 is arranged in parallel with the main cooling channel 102. The main refrigerant in the cooling flow passage 102 is the refrigerant from the discharge side flow passage that is returned from the fuel cell stack 22 towards the radiator 110 incorporated, the refrigerant in the main cooling flow passage 102 toward the fuel cell stack 22 from the radiator 110 back towards the supply side flow path flow. The diverted cooling flow path 104 reaches the second heat exchanger 120 of the ACP (48), where the compressed flow gas flow path 80 supplied from the ACP (48) to the humidifier 54 and the fuel cell stack 22 is supplied. The heat exchange is also performed and then returned to the main cooling channel 102. Thus, the second heat exchanger 120 has a function of adjusting the temperature of the supply gas. Conventionally, this function is executed by an independent cooling system called an intercooler. However, in the configuration of FIG. 2, this conventional intercooler function is shared with the cooling system from the radiator 110 to the fuel cell stack 22 with the refrigerant. Integrated.

Here, the circulation pump 130 is provided in the supply side flow path of the main cooling flow path 102, and is provided on the upstream side of the humidifier 54 and downstream of the refrigerant return diversion position of the diversion cooling flow path 104. Stated with reference to FIG. 2, the humidifier 54 is disposed upstream of the fuel cell stack 22 at the downstream side of the circulation pump 130, the second heat exchanger 120 is a top downstream of the radiator 110 fuel coolant taken from below stream side of the cell stack 22. That is, there are the radiator 110 and the second heat exchanger 120 as the refrigerant flows upstream of the circulation pump 130, and the humidifier 54 and the fuel cell stack 22 as the refrigerant flows downstream of the circulation pump 130. is there.

In the fuel cell cooling system 140 of FIG. 3, the circulation pump 130 is provided in the supply-side flow path of the main cooling flow path 102, and is located downstream of the radiator 110 and upstream of the refrigerant intake and diversion position of the diversion cooling flow path 144. Is provided. Referring to FIG. 3, the humidifier 54 is disposed downstream of the circulation pump 130 and upstream of the fuel cell stack 22, and the second heat exchanger 120 is downstream of the radiator 110 and is connected to the circulation pump. coolant taken from downstream side 130. That is, only the radiator 110 exists as the refrigerant flows on the upstream side of the circulation pump 130, and the second heat exchanger 120, the humidifier 54, and the fuel cell stack 22 indicate that the refrigerant flows on the downstream side of the circulation pump 130. There is.

In the fuel cell cooling system 150 of FIG. 4, the circulation pump 130 is provided in the supply-side flow path of the main cooling flow path 102, and the fuel is returned at the refrigerant return branch position of the shunt cooling flow path 154 and downstream of the humidifier 54. It is provided immediately upstream of the battery stack 22. Stated with reference to FIG. 4, the humidifier 54, a upstream side of the circulation pump 130 arranged downstream of the radiator 110, the second heat exchanger 120 is a top downstream of the radiator 110 humidifier under downstream vessels 54, coolant taken from downstream of the fuel cell stack 22. That is, there are the radiator 110, the second heat exchanger 120, and the humidifier 54 as the refrigerant flows on the upstream side of the circulation pump 130, and only the fuel cell stack 22 as the refrigerant flows on the downstream side of the circulation pump 130. There is.

In the cooling system including the air conditioning heat exchanger, the manner in which the refrigerant is distributed can be changed according to the manner in which the air conditioning shunt cooling passage is divided from the main cooling passage and the arrangement manner of the circulation pump 130. Figure 6 is a diagram coolant intake diverted position is provided immediately before the radiator 110 shows the configuration of a cooling system 180 of a fuel cell which diverts coolant to the air conditioning heat exchanger 170 in the main cooling flow passage 102. Elements similar to those in FIG. 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

In the cooling system 180 of a fuel cell in FIG. 6, the refrigerant intake bypass location for the air conditioning heat exchanger 170 in the main cooling flow passage 102 downstream of the fuel cell stack 22, an upstream side of the radiator 110. Referring to FIG. 6, the humidifier 54 is disposed downstream of the circulation pump 130 and upstream of the fuel cell stack 22, and the air conditioning heat exchanger 170 is immediately after the downstream outlet of the fuel cell stack 22. Thus, the refrigerant is taken in from the upstream side of the radiator 110 . When the shutoff valve 168 is open, it diverted refrigerant taken in is supplied to the heater 16 6 the air conditioning heat exchanger 170, again returned to the main cooling flow passage 102. This refrigerant return position is downstream of the radiator 110 and upstream of the circulation pump 130 .

In the above description, the main cooling flow path 102 has been described as passing through the humidifier 54, but it may be configured not to pass through the humidifier 54 . The following will be described for such a configuration. In the following, the same elements as those in FIGS. 1 to 10 are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 11 is a diagram showing a configuration of a fuel cell cooling system 300. The fuel cooling system 300 of the battery, compared cooling system 100 of a fuel cell described in FIG. 2, the main cooling flow passage 102 is in the humidifier 54 and passing over the city construction. Here, as described with reference to FIG. 2, the fuel cell cooling system 300 is arranged in parallel with the main cooling flow path 102 and the main cooling flow path 102 as a flow path for the refrigerant. A shunt cooling flow path 104 for shunting is provided.

In the fuel cell cooling system 340 of FIG. 12, the circulation pump 130 is provided in the supply-side flow path of the main cooling flow path 102, and is located downstream of the radiator 110 and upstream of the refrigerant intake and diversion position of the diversion cooling flow path 144. Provided on the side. Stated with reference to FIG. 12, the second heat exchanger 120, the downstream side of the circulation pump 130 downstream of the radiator 110, coolant taken from the upper stream side of the fuel cell stack 22. That is, only the radiator 110 is the refrigerant that flows on the upstream side of the circulation pump 130, and the second heat exchanger 120 and the fuel cell stack 22 are the one that the refrigerant flows on the downstream side of the circulation pump 130.

In the cooling system including the air conditioning heat exchanger, the manner in which the refrigerant is distributed can be changed according to the manner in which the air conditioning shunt cooling passage is divided from the main cooling passage and the arrangement manner of the circulation pump 130. Figure 15 is a diagram coolant intake diverted position is provided immediately before the radiator 110 shows the configuration of a cooling system 380 of a fuel cell which diverts coolant to the air conditioning heat exchanger 170 in the main cooling flow passage 102.

Claims (18)

A fuel cell cooling system in which fuel gas is supplied to the anode side and oxidizing gas is supplied to the cathode side to generate electric power by an electrochemical reaction,
A cooling flow path for circulating a refrigerant between the fuel cell stack and the radiator;
A second heat exchanger that is provided in parallel to the fuel cell stack with respect to the cooling flow path and into which the refrigerant in the cooling flow path is diverted;
A fuel cell cooling system comprising: A fuel cell cooling system in which fuel gas is supplied to the anode side and oxidizing gas is supplied to the cathode side to generate electric power by an electrochemical reaction,
A cooling flow path for circulating a refrigerant between the fuel cell stack and the radiator;
A second heat exchanger that is provided in parallel to the radiator and from which the refrigerant in the cooling flow path is diverted;
A fuel cell cooling system comprising: A fuel cell cooling system according to claim 1,
The fuel cell cooling system, wherein the second heat exchanger also serves as a cooling device for the gas compressor for supplying the oxidizing gas. The fuel cell cooling system according to any one of claims 1 to 3,
The fuel cell is a vehicle fuel cell mounted on a vehicle,
An air conditioning heat exchanger for air conditioning of a passenger compartment is provided in parallel with the fuel cell stack, and a coolant in the cooling flow path is diverted. The fuel cell cooling system according to any one of claims 1 to 3,
A refrigerant circulation pump arranged in series in the cooling flow path;
A humidifier arranged in parallel with a gas inlet and a gas outlet for supplying an oxidizing gas to the cathode side of the fuel cell;
With
The humidifier is disposed downstream of the refrigerant circulation pump and upstream of the fuel cell stack,
The second heat exchanger is a fuel cell cooling system, wherein the refrigerant is taken in from the downstream side of the radiator and the upstream side of the refrigerant circulation pump. The fuel cell cooling system according to any one of claims 1 to 3,
A refrigerant circulation pump arranged in series in the cooling flow path;
A humidifier arranged in parallel with a gas inlet and a gas outlet for supplying an oxidizing gas to the cathode side of the fuel cell;
With
The humidifier is disposed downstream of the refrigerant circulation pump and upstream of the fuel cell stack,
The second heat exchanger is a fuel cell cooling system, wherein the refrigerant is introduced from the downstream side of the refrigerant circulation pump and from the upstream side of the humidifier. The fuel cell cooling system according to any one of claims 1 to 3,
A refrigerant circulation pump arranged in series in the cooling flow path;
A humidifier arranged in parallel with a gas inlet and a gas outlet for supplying an oxidizing gas to the cathode side of the fuel cell;
With
The humidifier is arranged on the upstream side of the refrigerant circulation pump and on the downstream side of the radiator,
The second heat exchanger is a fuel cell cooling system, wherein a refrigerant is taken in from a downstream side of the radiator and an upstream side of the humidifier. The fuel cell cooling system according to claim 4, wherein
A refrigerant circulation pump arranged in series in the cooling flow path;
A humidifier arranged in parallel with a gas inlet and a gas outlet for supplying an oxidizing gas to the cathode side of the fuel cell;
With
The humidifier is disposed downstream of the refrigerant circulation pump and upstream of the fuel cell stack,
A cooling system for a fuel cell, wherein the air conditioning heat exchanger is provided with a refrigerant from a downstream side of the humidifier and an upstream side of the fuel cell stack. The fuel cell cooling system according to claim 4, wherein
A refrigerant circulation pump arranged in series in the cooling flow path;
A humidifier arranged in parallel with a gas inlet and a gas outlet for supplying an oxidizing gas to the cathode side of the fuel cell;
With
The humidifier is disposed downstream of the refrigerant circulation pump and upstream of the fuel cell stack,
The air conditioning heat exchanger is a cooling system for a fuel cell, wherein the refrigerant is taken in from the downstream side of the radiator and the upstream side of the refrigerant circulation pump. The fuel cell cooling system according to any one of claims 1 to 3,
A refrigerant circulation pump arranged in series in the cooling flow path;
A humidifier arranged in parallel with a gas inlet and a gas outlet for supplying an oxidizing gas to the cathode side of the fuel cell;
A diversion position switching means for switching the positions of the inlet and outlet of the diversion flow path for diverting the refrigerant from the cooling flow path to the second heat exchanger on the cooling flow path;
A fuel cell cooling system comprising: The fuel cell cooling system according to claim 4, wherein
A refrigerant circulation pump arranged in series in the cooling flow path;
A humidifier arranged in parallel with a gas inlet and a gas outlet for supplying an oxidizing gas to the cathode side of the fuel cell;
A diversion position switching means for switching the position of the inlet and outlet of the diversion flow path for diverting the refrigerant from the cooling flow path to the air conditioning heat exchanger;
A fuel cell cooling system comprising: The fuel cell cooling system according to claim 4, wherein
A refrigerant circulation pump arranged in series in the cooling flow path;
A flow-dividing flow path through which the refrigerant diverted from the cooling flow path flows, including an air-conditioning heat exchanger, a heater, and a second refrigerant circulation pump;
A circulation channel arranged in parallel with the air conditioning shunt channel;
Air-conditioning diversion switching means for switching the connection relationship between the cooling flow path and the circulation flow path for the air-conditioning diversion flow path;
A fuel cell cooling system comprising: The fuel cell cooling system according to claim 12, wherein
Air conditioning diversion switching means
A closed-loop connection state in which the air-conditioning branch flow path and the circulation flow path are connected so as to be a closed loop, and each is separated from the cooling flow path,
A direct connection state in which the air-conditioning branch flow path and the cooling flow path are directly connected and separated from the circulation flow path;
The fuel cell cooling system is characterized in that the connection relationship is switched between the two. The fuel cell cooling system according to claim 13,
The second circulation pump is a pump having a low flow rate operating efficiency better than the first circulation pump,
further,
A means for controlling the operation of the first circulation pump and the operation of the second circulation pump in accordance with the operating state of the fuel cell, wherein the operation of the first circulation pump is performed when the fuel cell is in a low load operation state. A fuel cell cooling system comprising pump operation control means for stopping and circulating a refrigerant through the fuel cell stack by a second circulation pump. The fuel cell cooling system according to any one of claims 1 to 3,
A refrigerant circulation pump arranged in series in the cooling flow path;
The second heat exchanger is a fuel cell characterized in that the refrigerant is taken in from the upstream side of the radiator and the downstream side of the fuel cell stack, and the refrigerant is returned to the downstream side of the radiator and the upstream side of the fuel cell stack. Cooling system. The fuel cell cooling system according to any one of claims 1 to 3,
A refrigerant circulation pump arranged in series in the cooling flow path;
The second heat exchanger is a fuel cell cooling system, wherein the refrigerant is introduced from the downstream side of the refrigerant circulation pump and from the upstream side of the fuel cell stack. The fuel cell cooling system according to claim 4, wherein
A refrigerant circulation pump arranged in series in the cooling flow path;
The air conditioning heat exchanger is a fuel cell cooling system, wherein the refrigerant is introduced from the downstream side of the refrigerant circulation pump and from the upstream side of the fuel cell stack. The fuel cell cooling system according to claim 4, wherein
A refrigerant circulation pump arranged in series in the cooling flow path;
The air conditioning heat exchanger is a fuel cell cooling system in which a refrigerant is introduced from the downstream side of the fuel cell stack and the upstream side of the radiator.

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