JP4923979B2 - Coordinated cooling system for fuel cell and air conditioning - Google Patents

Description

  The present invention relates to a coordinated cooling system for a fuel cell and an air conditioner, and more particularly to a coordinated cooling system for a fuel cell and an air conditioner that performs coordinated control by sharing a refrigerant between the fuel cell cooling system and the air conditioning cooling system.

  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, in Patent Document 1, in a vehicle heating device using cooling water of a fuel cell, a heat core that uses the warmed cooling water and a combustion heater are used, and a three-way valve or the like is provided depending on the cooling water temperature. It is disclosed to control and change the cooling water route. Here, when the cooling water temperature is low, the three-way valve is closed to cut off the cooling water route of the fuel cell and the cooling water route including the combustion heater, and each is made independent. On the other hand, when the cooling water temperature rises, the three-way valve is opened to supply a part of the cooling water for the fuel cell to the heat core, which is used for heating the passenger compartment.

JP 2002-127734 A

  As described above, the cooling water route is changed by opening and closing the three-way valve, and the heat of the cooling water heated by the fuel cell is used for heating the passenger compartment by the heat core, so that the fuel cell cooling system and the air conditioning system are harmonized. Coordinated control is performed. In this case, in the fuel cell cooling system and the air conditioning system, elements having the same type of function, such as a cooling water circulation pump, may be arranged in each cooling route. If these elements having the same type of function can also perform cooperative control, it is possible to reduce power consumption, improve fuel consumption, and the like.

  An object of the present invention is to provide a fuel cell and air conditioning cooperative cooling system capable of performing cooperative control on elements having similar functions. Another object is to provide a coordinated cooling system for a fuel cell and an air conditioner that can perform coordinated control of a cooling water pump for a fuel cell system and a cooling water pump for an air conditioning system. The following means contribute to at least one of these purposes.

A coordinated cooling system for a fuel cell and an air conditioner according to the present invention is a coordinated cooling system that performs coordinated control by sharing a refrigerant between a fuel cell cooling system and an air conditioning cooling system, and includes an FC stack that is a fuel cell main body, An FC circulation flow path for circulating the FC side refrigerant between the FC radiator and the FC radiator, an AC heat exchanger for exchanging heat between the AC heat pump as an air conditioning heat pump and the AC side refrigerant, and AC heat exchange An AC heat exchange flow path for disposing the vessel, a connection flow path for connecting both ends of the heat exchange flow path, an AC refrigerant flow path that circulates the AC refrigerant, and an FC circulation flow path. , A control valve provided between the AC circulation flow path and a closed state in which the FC circulation flow path and the AC circulation flow path are blocked, and at least one end of the connection flow path of the AC circulation flow path is opened. FC circulation flow through heat exchange channel A control valve that is connected in parallel to switch between a connection state in which the FC-side refrigerant and the AC-side refrigerant are shared, and when the control valve is in the connection state, the drive of the FC refrigerant pump and the drive of the AC refrigerant pump An AC refrigerant pump is a constant discharge flow rate type with a fixed discharge flow rate when operating, and a discharge flow rate capacity smaller than that of an FC refrigerant pump, The pump cooperative control unit performs control so that the FC refrigerant pump is continuously driven and stopped when the AC refrigerant pump is not necessary, and the constant discharge flow rate of the AC refrigerant pump When the AC refrigerant flow rate reaches the required flow rate for cooling the AC circulation flow path by driving both the FC refrigerant pump and the AC refrigerant pump, The driving of the C refrigerant pump is stopped.

  Moreover, it is preferable that a pump cooperation control part switches an AC refrigerant | coolant pump from a drive state to a stop state according to the rotation speed of FC refrigerant | coolant pump.

  In the fuel cell and air conditioning cooperative cooling system according to the present invention, the AC refrigerant pump is preferably a pump that causes the refrigerant to flow at a constant rotational speed.

  With the above configuration, the coordinated cooling system for the fuel cell and the air conditioner causes the FC refrigerant pump to be driven preferentially over the AC refrigerant pump when the control valve is in a connected state, and the AC refrigerant flow rate is driven by both driving. When the required flow rate is reached, the AC refrigerant pump is stopped. As a result, cooperative control of the FC refrigerant pump for the fuel cell system and the AC refrigerant pump for the air conditioning system can be performed, and fuel consumption can be improved.

  In addition, since the AC refrigerant pump is switched from the driving state to the stopped state in accordance with the rotational speed of the FC refrigerant pump, cooperative control between the FC refrigerant pump and the AC refrigerant pump can be performed, and fuel consumption can be improved. Can do.

  In addition, since the AC refrigerant pump is a pump that causes the refrigerant to flow at a constant rotation speed, for example, when the rotation speed of the FC refrigerant pump is low and the ability to flow the refrigerant is low, the AC refrigerant pump and the FC refrigerant pump are used in combination. In accordance with the characteristics of the FC refrigerant pump and the AC refrigerant pump, such as stopping the driving of the AC refrigerant pump when the rotational speed of the FC refrigerant pump increases and the refrigerant flow capacity becomes high and the required refrigerant flow rate can be made to flow. Coordinate pump control can be performed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Below, although demonstrated as what uses cooling water as a common refrigerant | coolant used for the cooperative cooling system of a fuel cell and an air conditioning, fluid refrigerants other than cooling water may be sufficient. In addition, although the cooling system on the fuel cell stack side performs cooperative cooling with respect to the air compressor (ACP), a configuration that does not include cooperative cooling with respect to the ACP may be employed. In addition, the AC heat exchanger that exchanges heat between the common refrigerant and the air conditioning heat pump and the heat core will be described as being arranged in the cooling system on the air conditioning side. It can also be set as the structure included in. For example, an auxiliary heater or the like may be included in the air conditioning side cooling system.

  Since the fuel cell and air conditioning cooperative 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 fuel cell and air conditioning cooperative cooling system will be installed. State.

  FIG. 1 is a configuration diagram of a fuel cell operation system 10 to which a cooperative cooling system of a fuel cell and air conditioning is applied. The fuel cell operation system 10 includes an operation system main body 20 and a control unit 70 that controls each element of the operation system main body 20 as the entire system.

  The operation system main body 20 includes a fuel cell main body called a fuel cell stack 22 in which a plurality of fuel cells are stacked, elements for supplying hydrogen gas arranged on the anode side of the fuel cell stack 22, and a cathode side. It is comprised including each element for the air supply arrange | positioned.

  The fuel cell stack 22 is formed by laminating a plurality of unit cells in which separators are arranged and sandwiched on both outer sides of an MEA (Membrane Electrode Assembly) in which catalyst electrode layers are arranged on both sides of an electrolyte membrane. The fuel cell stack 22 has a function of supplying a fuel gas such as hydrogen to the anode side, supplying an oxidizing gas containing oxygen, for example, air, to the cathode side, generating power by a cell chemical reaction through the electrolyte membrane, and taking out necessary power. Have The generated power is detected by the FC generated power detection unit 68, and the data of the detected generated power is transmitted to the control unit 70.

  The anode-side hydrogen gas source 24 is a tank that supplies hydrogen as a fuel gas. The regulator 26 connected to the hydrogen gas source 24 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 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 oxidant gas source 40 on the cathode side can actually use the atmosphere. The atmospheric air as the oxidizing gas 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 oxidizing gas source 40. The oxidizing gas thermometer 46 provided after the filter 42 has a function of detecting the temperature of the gas from the oxidizing gas source 40.

  The air compressor (ACP) 48 is a gas booster that compresses the volume of oxidizing gas by the motor 50 to increase its pressure. In addition, the ACP 48 has a function of providing a predetermined amount of oxidizing gas by changing the rotation speed (the number of rotations per minute) under the control of the control unit 70. That is, when the required flow rate of the oxidizing gas is large, the rotational speed of the motor 50 is increased. Conversely, when the required flow rate of the oxidizing gas is small, the rotational speed of the motor 50 is decreased. The ACP power consumption detection unit 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 motor 50 increases power consumption when the rotation speed is increased, and decreases power consumption when the rotation speed is decreased. Therefore, the power consumption is closely related to the motor rotation speed or the oxidizing gas flow rate.

  The humidifier 54 has a function of appropriately humidifying the oxidizing gas and efficiently performing the fuel cell reaction in the fuel cell stack 22. The oxidizing 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 appropriately wet the oxidizing gas. As described above, the humidifier 54 has a function of appropriately giving water vapor to the oxidizing gas, and a gas exchanger using a so-called hollow fiber can be used.

  Here, the flow path connecting the oxidizing gas source 40 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 oxidizing gas path 66 that is an oxidizing gas path enters the fuel cell stack 22 from the inlet side channel through the humidifier 54 from the oxidizing gas source 40, and passes through the humidifier 54 from the outlet side channel. Extends to the open air.

  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 referred to as a back pressure valve, and is a valve having a function of adjusting the gas pressure at the cathode side outlet and adjusting the flow rate of the oxidizing gas to the fuel cell stack 22. 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 diluter 64 collects the waste water containing hydrogen from the exhaust valve 34 on the anode side and the exhaust gas containing hydrogen leaking 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.

  The control unit 70 controls the above-described elements of the operation 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 controlling the rotational speed of the ACP 48 and controlling the pressure regulating valve 60 based on the required power generation amount and the generated power data transmitted from the FC generated power detection unit 68. Have. In addition, the control part 70 can have the function of the cooperation cooling control part 150 mentioned later. These functions can be realized by software, specifically, by executing a corresponding fuel cell operation program or 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 oxidizing gas. The ACP 48 also generates heat from the motor 50 and the like during its operation. Furthermore, it is preferable that the temperature of the oxidizing gas supplied to the cathode side of the fuel cell stack 22 is appropriate.

  In addition, 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, but waste heat from the fuel cell stack 22 is used, for example, when the vehicle interior is cold. If possible, it is desirable to use it to bring the interior of the vehicle to an appropriate temperature in a short time. On the other hand, if the low-temperature fuel cell stack 22 can be warmed up using elements of the air conditioning system at the time of starting the fuel cell stack 22, the fuel cell stack 22 can be operated at an early stage.

  As described above, the operation of the fuel cell and the air conditioning operation as a whole are performed by cooperatively controlling the cooling and the like between the elements constituting the fuel cell operation system 10 and the elements constituting the air conditioning system. It can be efficient. For this purpose, a cooperative cooling system for fuel cells and air conditioning is provided.

  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. The refrigerant flowing through the main cooling flow path and the shunt cooling flow path is mainly composed of water. 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.

  For the cooling of the ACP 48, the radiator is regarded as the first heat exchanger and is referred to as the second heat exchanger. In this case, the second heat exchanger is configured to be integrated as a cooling system by exchanging heat with an intercooler for independently cooling the conventional ACP 48 using the diverted refrigerant. The intercooler may be maintained as an independent cooling system as before, and the second heat exchanger may be used for cooling other elements.

  What is used for vehicle interior air conditioning is heat exchange between the heat of the divided refrigerant and the air blown from the blower, and heat exchange between the refrigerant gas of the air conditioning system and the refrigerant of the diverted cooling flow path. These are distinguished from each other, and the former will be referred to as a heat core and the latter as an AC heat exchanger. AC is an acronym for Air Conditioner and refers to an air conditioning system.

  The air conditioning system uses a so-called heat pump that performs cooling and heating by performing a cycle of compression and expansion of refrigerant gas. For example, when cooling is performed, the refrigerant gas is compressed by a compressor, heated to an air heat exchange with an outdoor heat exchanger, cooled with an expansion valve, cooled with an indoor heat exchanger to exchange air with the air, and the cold air is brought indoors. Send it in. When heating is performed, conversely, the refrigerant gas, which has been compressed and heated, is heat-exchanged with blown air by an indoor heat exchanger, and warm air is sent into the room. In the following description, it is assumed that a heat pump is used for cooling, and the indoor heat exchanger exchanges heat with air and sends cold air into the passenger compartment. And the AC heat exchanger is arrange | positioned in series with an outdoor heat exchanger, and the structure which flows the refrigerant gas which raised temperature into an AC heat exchanger is taken. As described above, an indoor heat exchanger and an outdoor heat exchanger are used in a heat pump type air conditioning system, which exchanges heat with cooling water that is a refrigerant used in the main cooling flow path or the diverted cooling flow path. Not what you want. The AC heat exchanger exchanges heat with the refrigerant gas of the air conditioning system and the cooling water that is the refrigerant used in the shunt cooling flow path, and is provided separately from the indoor heat exchanger and the outdoor heat exchanger.

  FIG. 2 is a diagram illustrating a configuration of a cooperative cooling system 80 for fuel cells and air conditioning. The fuel cell and air conditioning cooperative cooling system 80 includes a cooperative cooling system main body 82 and a cooperative cooling control unit 150. Here, FIG. 2 shows elements for cooperative cooling extracted from the fuel cell system for a vehicle. The fuel cell operation system 10 described in FIG. 1 and the cooperative cooling system for this fuel cell and air conditioning are shown in FIG. Together, they constitute one vehicle fuel cell system. Therefore, the cooperative cooling system main body 82 in FIG. 2 constitutes the system main body in the vehicle fuel cell system together with the operation system main body 20 in FIG. Further, as described above, the cooperative cooling control unit 150 can be configured as a part of the control unit 70 described in FIG.

  As shown in FIG. 2, the cooperative cooling system main body 82 includes a cooling system on the cathode side in the fuel cell operation system 10 and an air conditioning system 130. Of course, depending on the case, a cooling system on the anode side may be included. In addition, although it does not comprise the cooperative cooling system main-body part 82, the vehicle interior 8 is shown by FIG. 2 as an object to which the air-conditioned air is supplied.

  In FIG. 2, the fuel cell stack 22 is shown as elements of the fuel cell operating system 10, and the ACP 48, the motor 50, the humidifier 54, and the oxidizing gas path 66 are shown as elements on the cathode side. The oxidizing gas path 66 is indicated by a thin line, whereas the flow path through which the refrigerant flows is indicated by a thick line.

  The flow path through which the refrigerant flows is roughly divided into a fuel cell side circulation path for circulating the refrigerant between the fuel cell stack 22 and the radiator 100, and an air conditioning side for circulating the refrigerant for air conditioning in relation to the air conditioning system 130. It can be divided into a circulation channel. Here, the two are distinguished, and the former is called an FC circulation flow path and the latter is called an AC circulation flow path. FC is an acronym for Fuel Cell and refers to a fuel cell system. In the cooperative cooling, the FC circulation flow path and the AC circulation flow path are blocked or connected in accordance with the operation status of the fuel cell stack 22, the operation status of the air conditioning system 130, and the like. When both are cut off, the refrigerant flows through each circulation channel independently of each other. Therefore, the refrigerant flowing through the FC circulation channel and the AC circulation channel are physically the same, but the temperature, the flow rate, the flow velocity, and the like may be different. Can be referred to as the FC-side refrigerant, and the refrigerant flowing through the AC circulation channel can be referred to as the AC-side refrigerant.

  From another viewpoint, the cooperative cooling system main body 82 is provided with a main cooling flow path 84 as a flow path through which the refrigerant flows, and is further arranged in parallel with the main cooling flow path 84 to separate the same refrigerant. Cooling channels 86 and 90 are provided. The diversion cooling flow path 86 is for the ACP 48, and the diversion cooling flow path 90 is for air conditioning. Here, the main cooling flow path 84 and the diversion cooling flow path 86 for the ACP 48 constitute an FC circulation flow path. The shunt cooling channel 90 for air conditioning constitutes an AC circulation channel.

  As the refrigerant, LLC (Long Life Coolant) mainly composed of water can be used. Below, in order to distinguish with the refrigerant gas of the air conditioning system 130, the refrigerant | coolant which uses LLC etc. will only be called cooling water.

  In the main cooling flow path 84, the radiator 100 including the fan 102, the heater 104 for heating, the three-way valve 106 for appropriately diverting the cooling water to the heater 104, and the cooling water as the FC-side refrigerant are circulated. FC refrigerant pump (WP1) 108 is disposed for this purpose. The cooling water flowing through the main cooling flow path 84 circulates between the radiator 100 and the fuel cell stack 22, the heat of the fuel cell stack 22 whose temperature has risen is carried away by the cooling water, cooled by the radiator 100, and again the fuel cell. It has a function of returning to the stack 22.

  As the FC refrigerant pump 108, a fluid pump suitable for flowing cooling water can be used. For example, it is possible to change the flow rate or the flow rate of the cooling water flowing through the FC circulation flow path by the rotation speed control using a fluid pump whose discharge flow rate increases according to the rotation speed. Thus, the flow rate of the cooling water circulation between the fuel cell stack 22 and the radiator 100 can be changed by changing the flow rate of the FC cooling water in accordance with the operation state of the fuel cell stack 22. In this manner, the temperature of the FC cooling water can be maintained at a temperature suitable for the operation of the fuel cell stack 22 by controlling the rotational speed of the FC refrigerant pump 108.

  An FC cooling water thermometer 112 is provided on the outlet side of the fuel cell stack 22 in the main cooling flow path 84 as FC refrigerant temperature detecting means for detecting the cooling water temperature that is the temperature of the FC side refrigerant. Detection data of the FC cooling water thermometer 112 is transmitted to the cooperative cooling control unit 150.

  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, but the cooling water in the main cooling flow path 84 is supplied from the humidifier 54. Do not pass. That is, the humidifier 54 is not cooled by the cooling water in the main cooling channel 84. Of course, when the humidifier 54 needs to be cooled, the main cooling channel 84 is passed through the humidifier 54, and heat is exchanged with the humidifier by the cooling water of the main cooling channel 84. Also good.

  A shunt cooling channel 86 for the ACP 48 is arranged in parallel with the main cooling channel 84. Then, the cooling water is taken in from the discharge-side flow path in which the cooling water in the main cooling flow path 84 is returned from the fuel cell stack 22 toward the radiator 100, and the cooling water in the main cooling flow path 84 is transferred from the radiator 100 to the fuel cell stack 22. The cooling water that has been diverted to the supply-side flow path that flows toward is returned. The shunt cooling flow path 86 enters the second heat exchanger 110 from the motor 50 side of the ACP 48, where the compressed oxidizing gas supplied from the ACP 48 to the humidifier 54 and the fuel cell stack 22 flows to the oxidizing gas path 66. Heat exchange is then performed and then returned to the main cooling channel 84. Therefore, the second heat exchanger 110 has a function of adjusting the temperature of the oxidizing 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 by the cooling system from the radiator 100 to the fuel cell stack 22 and the cooling water. It has become a form to be integrated.

  Here, the FC refrigerant pump 108 is provided in the supply side flow path of the main cooling flow path 84, and is provided downstream of the cooling water return diversion position of the diversion cooling flow path 86. Referring to FIG. 2, the second heat exchanger 110 receives cooling water from the downstream side of the radiator 100 and the upstream side of the FC refrigerant pump 108. That is, the radiator 100 and the second heat exchanger 110 are provided as the coolant flows upstream of the FC refrigerant pump 108, and the fuel cell stack 22 is provided as the coolant flows downstream of the FC refrigerant pump 108.

  Therefore, in this configuration, if the shunt cooling flow path 90 for air conditioning is separated, (the amount of cooling water flowing through the radiator 100) + (the amount of cooling water flowing through the second heat exchanger 110) = the total amount of cooling water = Therefore, a considerably large amount of cooling water 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 100 side. Further, the ratio of (the amount of cooling water flowing through the radiator 100) and (the amount of cooling water flowing through the second heat exchanger 110) can also be determined by the ratio of these flow path resistances, or the control for controlling the diversion ratio. Using the valves, the amount of cooling water flowing through these can be determined, and the radiator 100 and the second heat exchanger 110 can be operated cooperatively.

  Further, since the shunt cooling flow path 86 is provided in parallel with the main cooling flow path 84, the temperature of the cooling water discharged from the second heat exchanger 110 and the temperature of the cooling water discharged from the fuel cell stack 22 are The difference can be reduced. The former defines the oxidizing gas temperature on the oxidizing gas inlet side of the humidifier 54, and the latter defines the temperature of the oxidizing gas outlet of the humidifier 54, so that the temperature difference between both ends of the gas inlet 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 cooperative cooling system main body 82 of FIG. 2, in addition to the shunt cooling flow path 86 for the ACP 48, a shunt cooling flow path 90 for air conditioning is further provided. The shunt cooling flow path 90 for air conditioning constitutes an AC circulation flow path as described above, and includes two heat exchangers and an AC refrigerant pump that circulates the AC-side refrigerant in the path ( WP2) 126. One of the two heat exchangers is a heat core 120 and the other is an AC heat exchanger 124. And the shunt cooling flow path 90 which is AC circulation flow path is comprised from the flow path in which these two heat exchangers are arrange | positioned, and the flow path which connects the both ends of the flow path. The former is called an AC heat exchange flow path 94 and the latter is called a connection flow path 92.

  The AC refrigerant pump 126 is a pump for flowing AC cooling water, and an appropriate fluid pump can be used. Since the flow rate of the cooling water flowing through the AC circulation flow path is generally smaller than the flow rate of the cooling water flowing through the FC circulation flow path, the AC refrigerant pump 126 is smaller than the FC refrigerant pump 108. Can be used. There are many types of small fluid pumps in which the number of rotations is fixed and the discharge flow rate cannot be changed. However, even such a constant flow rate type fluid pump can be sufficiently used. Of course, in some cases, a fluid pump of a type that can change the discharge flow rate at a variable rotation speed may be used.

Both ends of the AC heat exchange flow path 94 are connected to the connection flow path 92, and the two connection points and the FC circulation flow path are connected by the branch flow path 85 and the extension flow path 91, respectively. Is done. And the three-way valve 96 is provided in the connection point where three flow paths, the AC heat exchange flow path 94, the connection flow path 92, and the branch flow path 85 from the FC circulation flow path gather. In the example of FIG. 2, the three-way valve is not provided at the connection point where the three heat flow paths 94, the connection flow path 92, and the extension flow path 91 to the FC circulation flow path gather. In some cases, a three-way valve can also be provided here.
The operation of the three-way valve 96 will be described later.

  The heat core 120 is a pipe member that flows cooling water, which is an AC-side refrigerant, and exchanges heat between the AC-side refrigerant and the air by flowing air from the blower 122 on the outside. For example, when the AC-side refrigerant is warm, the air from the blower 122 is warmed and supplied to the vehicle interior 8 to heat the vehicle interior. Thus, the heat core 120 performs air conditioning using the heat of hot water, so to speak, it is a hot water heater.

  The AC heat exchanger 124 performs heat exchange between the refrigerant gas of the air conditioning system 130 and the cooling water that is the AC-side refrigerant. As described above, the air conditioning system 130 is a heat pump type that performs a cycle of compression and evaporation of a refrigerant gas such as carbon dioxide gas, and the indoor heat exchanger 138 The cold air is sent into the passenger compartment and the waste heat of the compressed and heated refrigerant gas is released to the outside by the outdoor heat exchanger 134. In FIG. 2, as components of the air conditioning system 130, a compressor (CP) 132 that compresses refrigerant gas, an outdoor heat exchanger 134, an expansion valve (EV) 136 that expands refrigerant gas, an indoor heat exchanger 138, outdoor heat A fan 140 is shown for releasing waste heat in the exchanger 134 to the outside air. When there is a cooling request, the refrigerant gas circulates in a circulation path connecting the compressor 132, the AC heat exchanger 124, the outdoor heat exchanger 134, the expansion valve 136, and the indoor heat exchanger 138. Since the gas refrigerant of the air conditioning system 130 and the cooling water flow inside the AC heat exchanger 124, heat exchange can be performed between the gas refrigerant and the cooling water. For example, the heat of the hot gas refrigerant can be applied to the cooling water to warm the cooling water.

  In addition to the air conditioning system 130, air conditioning using the heat core 120 and the AC heat exchanger 124 can be performed as follows. When there is a cooling request from the user or the like, the compressor 132 is driven. Then, the compressed refrigerant gas is expanded by the expansion valve 136 to lower the temperature, and is exchanged with the blown air from the blower 122 in the indoor heat exchanger 138. The heat of the blown air is taken to cool air and is sent into the vehicle interior 8. When there is a heating request from a user or the like, warm water warmed by the fuel cell stack 22 and diverted from the main cooling flow path 84 is caused to flow to the heat core 120, and air blown from the blower 122 is warmed to warm air and sent into the passenger compartment. At this time, the AC heat exchanger 124 also performs heat exchange between the hot refrigerant gas and the cooling water, and the cooling water is warmed, so that the warm air can be more effectively generated. When a user or the like requests dry air blowing, the cool air in the indoor heat exchanger 138 driven by the compressor 132 and the warm air from the heat core 120 are intermittently sent into the vehicle interior. In this way, the waste heat of the fuel cell stack 22 and the waste heat of the air conditioning system 130 are used, and cooling, heating, and dry air blowing can be performed without providing a heater that uses electric power.

  As shown in FIG. 2, the blower 122 can serve both for blowing the heat core 120 and blowing the indoor heat exchanger 138 of the air conditioning system 130. In order to avoid the hot air of the heat core 120 and the cold air of the indoor heat exchanger 138 from interfering with each other, a mechanism for changing the direction of the blower 122 can be provided. When the air is blown into the vehicle interior only through the heat core 120, or the air is blown into the vehicle interior only through the indoor heat exchanger 138, the air is blown into the vehicle interior via both the heat core 120 and the indoor heat exchanger 138. In this case, the switching between them can be performed. In addition, when the air is blown without passing through the heat core 120, the air blown through the heat core 120 can be discharged outside the passenger compartment. For example, a valve for changing the air flow path or a moving mechanism of the air blowing wall can be used as such a mechanism for changing the direction of the air blowing.

  Moreover, the fan 140 for the outdoor heat exchanger 134 of the air conditioning system 130 can also be used as the fan 102 used in the radiator 100 for the FC circulation flow path. Alternatively, the fan 140 and the fan 102 can be arranged in the same region, and both the radiator 100 and the outdoor heat exchanger 134 can be blown. When this arrangement is adopted, the amount of blown air can be adjusted according to the operating status of the fuel cell stack 22 and the operating status of the air conditioning system 130. For example, both the fan 102 and the fan 140 are driven to maximize the amount of air flow, or one of them is driven to reduce the amount of air flow to improve fuel efficiency. Any fan can stop driving if it can.

  The three-way valve 96 is a control valve whose connection is changed under the control of the cooperative cooling control unit 150. As described above, the three-way valve 96 gathers three flow paths, one end of the AC heat exchange flow path 94, one end of the connection flow path 92, the branch flow path 85 branched from the main cooling flow path 84. Provided at the junction. The control of the connection of the three-way valve 96 is performed by switching between the following two states based on the operating status of the fuel cell stack 22, the operating status of the air conditioning system 130, and the like.

  One is a blocking state in which the main cooling channel 84 of the FC circulation channel and the shunt cooling channel 90 which is the AC circulation channel are blocked. The other is a connection state in which the connection flow path 92 of the AC circulation flow path is opened and the AC heat exchange flow path 94 is connected in parallel to the FC circulation flow path to share the FC side refrigerant and the AC side refrigerant. is there. Specifically, the flow direction of the three-way valve 96 is a blocking state when the connection channel 92 and the AC heat exchange channel 94 are connected and not connected to the branch channel 85. The AC heat exchange flow path 94 and the branch flow path 85 are connected and the connection flow path 92 is not connected is in a connected state.

  FIG. 3 shows the shut-off state, and FIG. 4 shows the connected state. In the shut-off state, the FC circulation passage through which the cooling water on the fuel cell stack 22 circulates and the AC circulation passage through which the cooling water on the air conditioning side circulates are completely cut off. The flow path is completely separated. In the FC circulation flow path, the coolant that is the FC-side refrigerant circulates between the fuel cell stack 22 and the radiator 100 by the FC refrigerant pump 108. A shunt cooling channel 86 for the ACP 48 is provided in parallel with the main cooling channel 84. In the AC circulation flow path, the connection flow path 92 and the AC heat exchange flow path 94 are connected by a three-way valve 96, and the cooling water, which is the AC-side refrigerant, passes through the heat core 120 and the AC heat exchanger 124. Circulate by 126.

  As shown in FIG. 4, in the connected state, the AC circulation channel is connected in parallel to the FC circulation channel. That is, in the main cooling flow path 84 of the FC circulation flow path, the branch flow path 85 is branched from the upstream side of the radiator 100, the downstream side of the fuel cell stack 22, and the downstream side of the FC cooling water thermometer 112. The one-way side of the AC heat exchange channel 94 and the branch channel 85 are connected by the three-way valve 96, and the connection channel 92 is separated. The other end side of the AC heat exchange flow path 94 extends and becomes an extended flow path 91 connected to the main cooling flow path 84 of the FC circulation flow path. The extension channel 91 is connected to the downstream side of the radiator 100 and the downstream side of the FC refrigerant pump 108 and the upstream side of the fuel cell stack 22 in the main cooling channel 84 of the FC circulation channel. Therefore, in the connected state, the cooling water taken from the FC circulation flow path passes through the branch flow path 85, the AC heat exchange flow path 94, and the extension flow path 91 to pass through the AC refrigerant pump 126, the heat core 120, and the AC heat exchange. While flowing through the vessel 124, it is returned to the FC circulation flow path again.

  In this connected state, (amount of refrigerant flowing through radiator 100) + (amount of refrigerant flowing through second heat exchanger 110) = total amount of refrigerant = (amount of refrigerant flowing through fuel cell stack 22) + (heat core 120, AC heat exchange) Therefore, the refrigerant can be supplied for air conditioning while supplying an appropriate amount of refrigerant to the fuel cell stack 22.

  That is, with this configuration, it is possible to supply cooling water, which is a coolant that is warmed by the operation of the fuel cell stack 22 and maintained at an appropriate temperature by the radiator 100 and circulated, for air conditioning. When the fuel cell stack 22 is not sufficiently warmed, the cold refrigerant can be prevented from being fed into the AC circulation channel on the air conditioning side by closing the three-way valve 96.

  In this way, the refrigerant is shared between the FC circulation path for the fuel cell stack 22 and the AC circulation path for the passenger compartment air conditioning, and the three-way valve is set according to the temperature of the fuel cell stack 22 and the passenger compartment temperature. By controlling the opening and closing of 96, the cooling system of the fuel cell stack 22 and the passenger compartment air conditioning system can be integrated under cooperative control.

  Returning to FIG. 2 again, the cooperative cooling control unit 150 controls the above-described elements of the cooperative cooling system main body 82 as the entire system. The cooperative cooling control unit 150 can be configured by a computer, and as described above, can be configured as one computer such as a fuel cell CPU together with the function of the control unit 70 described in FIG.

  The cooperative cooling control unit 150 functions to cooperatively control the circulation of the cooling water on the fuel cell side and the circulation of the cooling water on the air conditioning side in accordance with the operation state of the fuel cell stack 22 and the operation state of the air conditioning system 130. Have In particular, here, the cooperative cooling control unit 150 performs switching control between the shut-off state and the connected state for the three-way valve 96 that is a control valve in accordance with the operation state of the fuel cell stack 22 and the operation state of the air conditioning system 130. The shut-off / connection switching module 152 to be executed, and the pump cooperative control module 154 that performs cooperative control of the FC refrigerant pump 108 and the AC refrigerant pump 126 are configured. These functions can be realized by software, specifically, by executing a corresponding cooling program for the fuel cell and air conditioning. Some of these functions can also be realized by hardware.

  Regarding the operation of the fuel cell and air conditioning cooperative cooling system 80 having the above-described configuration, the function of the pump cooperative control module 154 will be described with reference to FIGS. In the following description, the reference numerals in FIGS. 1 to 4 are used. FIG. 5 is a diagram showing the operation of each pump when the pump cooperative control is not performed, FIG. 6 is a flowchart showing a procedure of the pump cooperative control, and FIG. 7 is an operation characteristic of each pump when the pump cooperative control is performed. FIG.

In FIG. 5, the vertical axis represents the AC cooling water flow rate Q _AC in the air conditioning system, and the horizontal axis represents the WP1 rotational speed, which is the rotational speed of the FC refrigerant pump (WP1) 108. It is a figure which shows the relationship of these discharge flow rates. Here, the FC refrigerant pump 108 is a variable rotation speed type and uses a pump whose discharge flow rate increases in proportion to the rotation speed, and the AC refrigerant pump 126 uses a fixed rotation speed type and has a constant discharge flow rate. To do. Therefore, the discharge flow rate characteristic 160 of the FC refrigerant pump 108 is a flow rate proportional to the WP1 rotation speed, and the discharge flow rate characteristic 162 of the AC refrigerant pump 126 is a constant flow rate regardless of the WP1 rotation speed. Therefore, when cooperative control is not performed between the pumps, the total amount 164 of the discharge flow rates of the two pumps becomes the AC cooling water flow rate Q _AC . As shown in FIG. 5, the total amount 164 secures a constant discharge flow rate of the AC refrigerant pump 126 even when the WP1 rotation speed is 0, and the amount increases as the WP1 rotation speed increases.

  FIG. 6 is a flowchart showing a procedure of pump cooperative control. These procedures correspond to each processing procedure of the pump cooperative control in the cooperative cooling program of the fuel cell and the air conditioning, and are executed by the pump cooperative control module 154 of the cooperative cooling control unit 150. Here, it is assumed that the three-way valve 96 as a control valve is in a connected state (S10), the AC refrigerant pump 126 is driven (S12), and then the FC refrigerant pump 108 is driven (S14). Up to this point, there is no restriction condition between the driving of the two pumps. Therefore, the total amount of the discharge flow rates of the two pumps is equal to that of the AC refrigerant pump 126 when the WP1 rotation speed is 0, as described with reference to FIG. At a constant discharge flow rate, the amount increases as the WP1 rotation speed increases.

Next, whether WP1 speed predetermined threshold rotational speed N ₁ or more is determined (S16). If it is less than N ₁ , the monitoring of S16 is continued, and when the WP1 rotation speed becomes N ₁ or more, the driving of the AC refrigerant pump (WP2) 126 is stopped (S18).

Here, the threshold rotation speed N ₁ is set to a WP1 rotation speed that can satisfy the required amount Q ₀ as the AC refrigerant flow rate of the AC circulation flow path only by the discharge flow rate of the FC refrigerant pump 18. By doing so, when the flow rate of the AC refrigerant reaches the required amount Q ₀ by driving both the FC refrigerant pump 108 and the AC refrigerant pump 126, the driving of the AC refrigerant pump 126 is stopped and the driving of the FC refrigerant pump 108 is performed. Only possible.

This is shown in FIG. The vertical and horizontal axes in FIG. 7 are the same as those described in FIG. Under the cooperative control of the pump, the driving of the FC refrigerant pump 108 is continued, so that the discharge flow rate characteristic 160 is the same as that described in FIG. 5, and the discharge flow rate increases in proportion to the WP1 rotation speed. Then, the WP1 rotation speed at which the discharge flow rate is the same as the fixed discharge flow rate of the AC refrigerant pump 126 can be set as the threshold rotation speed N ₁ . That is, the constant discharge flow rate of the AC refrigerant pump 126 satisfies the necessary amount Q ₀ as the AC refrigerant flow rate of the AC circulation flow path even when WP1 is 0, that is, even when the FC refrigerant pump 108 is not driven. This is because the WP1 rotation speed satisfying the necessary amount Q ₀ can be set as the threshold rotation speed N ₁ . Incidentally, when a constant discharge flow rate of the AC refrigerant pump 126 is different from the required amount Q ₀ can be the WP1 speed corresponding to the required amount Q ₀ and N _1.

The discharge flow rate characteristic 170 of the AC refrigerant pump 126 continues to be driven until the WP1 rotation speed of the FC refrigerant pump 108 reaches N ₁ , and thereafter the drive is stopped. Therefore, the total amount 172 by the FC refrigerant pump 108 and the AC refrigerant pump 126 is such that the AC cooling water flow rate Q _AC is once the AC refrigerant in the AC circulation flow path when the WP1 rotational speed is N ₁ as shown in FIG. It is reduced to the required amount Q ₀ as a flow rate and then increases again.

As can be seen from comparison with FIG. 5, under the pump cooperative control, the execution of driving of the FC refrigerant pump 108 is prioritized over the execution of driving of the AC refrigerant pump 126. When the AC refrigerant flow reaches the required amount Q ₀ by driving both the FC refrigerant pump 108 and the AC refrigerant pump 126, the driving of the AC refrigerant pump 126 is stopped. As a result, unnecessary driving of the AC refrigerant pump 126 can be omitted, power consumption can be reduced, and fuel consumption can be improved.

  In the coordinated cooling system of the fuel cell and the air conditioning, in addition to the refrigerant circulation pump, elements having similar functions are arranged on the fuel cell side and the air conditioning side. For example, the fan 140 for the outdoor heat exchanger 134 of the air conditioning system 130 and the fan 102 used in the radiator 100 for the FC circulation flow path have the same functions. Therefore, by performing cooperative control also on these, power consumption can be reduced and fuel consumption can be improved. In the following, description will be made using the reference numerals in FIGS.

  In other words, the fan 140 and the fan 102 can be arranged in the same region, and both the radiator 100 and the outdoor heat exchanger 134 can be blown. When this arrangement is adopted, control can be performed cooperatively between the two fans 140 and 102 in accordance with the operation status of the fuel cell stack 22 and the operation status of the air conditioning system 130. For example, the fan 102 and the fan 140 can be driven together to maximize the amount of air flow. Further, when the amount of blown air is small as in the case where the fuel cell stack 22 is not operated, either one is driven and the other drive is stopped. As a result, it is possible to dispense with unnecessary driving of the fan, reduce power consumption, and improve fuel efficiency. In addition, when the vehicle is traveling and the traveling airflow is sufficient for cooling the radiator 100 or the like, if the driving of both the fans 102 and 140 is stopped, the driving of the useless fan can be further omitted. Power consumption can be reduced and fuel consumption can be improved.

1 is a configuration diagram of a fuel cell operation system to which a cooperative cooling system of a fuel cell and an air conditioner according to an embodiment of the present invention is applied. In embodiment which concerns on this invention, it is a figure which shows the structure of the coordinated cooling system of a fuel cell and an air conditioning. In embodiment which concerns on this invention, it is a figure which shows the mode of the cooperative cooling system main-body part when a three-way valve is the interruption | blocking state. In embodiment which concerns on this invention, it is a figure which shows the mode of the cooperative cooling system main-body part when a three-way valve is a connection state. In embodiment which concerns on this invention, it is a figure explaining the discharge flow volume characteristic etc. of each pump when not performing pump cooperative control. In embodiment which concerns on this invention, it is a flowchart which shows the procedure of pump cooperation control. In embodiment which concerns on this invention, it is a figure explaining the discharge flow volume characteristic etc. of each pump in the case of performing pump cooperative control.

Explanation of symbols

  8 Car interior, 10 Fuel cell operation system, 20 Operation 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 Oxidation gas source , 42 Filter, 44 Flow meter, 46 Oxidizing gas thermometer, 48 ACP, 50 Motor, 52 ACP power consumption detector, 54 Humidifier, 56 Pressure gauge, 60 Pressure regulating valve, 64 Diluter, 66 Oxidizing gas path, 68 FC Generated power detection unit, 70 control unit, 80 cooperative cooling system, 82 cooperative cooling system main body, 84 main cooling channel, 85 branch channel, 86, 90 split cooling channel, 91 extension channel, 92 connection channel, 94 AC heat exchange flow path, 96, 106 Three-way valve, 100 Radiator, 102, 140 Fan, 104 Heater, 106 Three-way valve, 108 FC refrigerant pump, 110 2nd heat exchanger, 112 FC cooling water thermometer, 120 heat core, 122 blower, 124 AC heat exchanger, 126 AC refrigerant pump, 130 air conditioning system, 132 compressor, 134 outdoor heat exchange , 136 expansion valve, 138 indoor heat exchanger, 150 cooperative cooling control unit, 152 shutoff / connection switching module, 154 pump cooperative control module, 160 FC refrigerant pump discharge flow characteristics, 162, 170 AC refrigerant pump discharge flow characteristics 164,172 Total amount.

Claims (3)

A cooperative cooling system that performs cooperative control by sharing a refrigerant between a fuel cell cooling system and an air conditioning cooling system,
An FC circulation passage for circulating an FC-side refrigerant by an FC refrigerant pump between an FC stack, which is a fuel cell body, and an FC radiator;
AC heat exchanger that performs heat exchange between an AC heat pump that is an air-conditioning heat pump and an AC-side refrigerant, an AC heat exchange channel that arranges the AC heat exchanger, and a connection flow that connects both ends of the heat exchange channel An AC circulation flow path that has a passage and an AC refrigerant pump, and circulates the AC-side refrigerant,
A control valve provided between the FC circulation flow path and the AC circulation flow path, at least one of a shut-off state that cuts off the FC circulation flow path and the AC circulation flow path, and a connection flow path of the AC circulation flow path A control valve for switching between a connection state in which the end is opened and the AC heat exchange flow path is connected in parallel to the FC circulation flow path to share the FC side refrigerant and the AC side refrigerant;
A pump cooperative control unit for cooperatively controlling the driving of the FC refrigerant pump and the driving of the AC refrigerant pump when the control valve is in a connected state;
With
The AC refrigerant pump is a constant discharge flow rate type in which the discharge flow rate when operating is fixed, and is a pump having a smaller discharge flow rate capability than the FC refrigerant pump,
The pump coordination controller
The FC refrigerant pump is continuously driven, and the AC refrigerant pump is controlled so that it is stopped when it is not necessary. A constant discharge flow rate of the AC refrigerant pump is necessary for cooling the AC circulation flow path. The AC refrigerant pump is stopped when the AC refrigerant flow reaches a required flow for cooling the AC circulation flow path by driving both the FC refrigerant pump and the AC refrigerant pump. Fuel cell and air conditioning cooperative control system. In the fuel cell and air conditioning cooperative control system according to claim 1,
The pump cooperative control unit switches the AC refrigerant pump from a driving state to a stopped state in accordance with the number of revolutions of the FC refrigerant pump. In the fuel cell and air conditioning cooperative control system according to claim 1,
The AC refrigerant pump is a pump that causes a refrigerant to flow at a constant rotational speed.

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