JP2011189864A - Device for adjusting refrigerant circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve energy efficiency by properly deciding cases between when heat of an electric heater is used and when waste heat of a fuel cell is used upon an air conditioning. <P>SOLUTION: The device includes: a circuit for the fuel cell; a circuit for cooling on which a radiator is arranged; a circuit for the air conditioning on which a heater core for heating is arranged; a first circuit configuration where the circuit for the fuel cell and the circuit for the air conditioning are connected to each other; and a circuit switching unit for switching a circuit among a plurality of circuit configurations which at least include a second circuit configuration where the first circuit configuration is further connected to the circuit for cooling. The circuit switching unit includes: a first thermostat 34 in which a switch of a flow passage when a temperature of a refrigerant is equal to or higher than a first temperature allows the circuit to switch to the first circuit configuration; and a second thermostat 35 in which a switch of the flow passage when the temperature of the refrigerant is equal to or higher than a second temperature being higher than the first temperature allows the circuit to switch to the second circuit configuration. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a refrigerant circuit adjusting device mounted on a vehicle including a fuel cell.

  2. Description of the Related Art Conventionally, in a vehicle equipped with a fuel cell, a technique for using waste heat of the fuel cell as a heat source for temperature adjustment in the passenger compartment is known. Specifically, the cooling water flowing through the cooling water circulation path in which the fuel cell is disposed is supplied to the heater core, and the air whose temperature is adjusted by the heater core is supplied to the vehicle interior. The supply of cooling water to the heater core is controlled by a three-way valve that is driven to open and close by a control device (for example, Patent Document 1).

JP 2001-315524 A

  However, the prior art requires a three-way valve and a control device that controls the three-way valve, and thus has a problem that the configuration is complicated.

  It is an object of the present invention to simplify the configuration and reduce the cost.

  The present invention can be realized as the following forms or application examples in order to solve at least a part of the above-described problems.

Application Example 1 A refrigerant circuit adjustment device mounted on a vehicle including a fuel cell, a circuit through which a refrigerant flows, a circuit for a fuel cell in which the fuel cell is disposed, and a circuit through which a refrigerant flows The cooling circuit in which the radiator is disposed, the refrigerant flow circuit, the air conditioning circuit in which the heater core for heating the vehicle interior is disposed, the fuel cell circuit, and the air conditioning circuit are connected to each other. A circuit switching unit for switching a circuit between a plurality of circuit forms including at least a first circuit form and a second circuit form to which the cooling circuit is further connected to the first circuit form; The circuit switching unit switches the flow path when the refrigerant temperature becomes equal to or higher than the first temperature, thereby switching the circuit to the first circuit configuration, and the refrigerant temperature is higher than the first temperature. Higher second By switching the flow path when a higher degree, the refrigerant circuit adjustment device and a second thermostat for switching circuit to the second circuit configuration.

  According to the refrigerant circuit adjusting device described in the application example 1, the first circuit configuration in which the cooling of the fuel cell refrigerant is performed using the air conditioning circuit, and the cooling of the fuel cell refrigerant is performed using the air conditioning circuit and the radiator. The circuit switching to the second circuit configuration can be performed with two thermostats. Since the thermostat automatically switches the flow path according to the temperature, it does not require a three-way valve or a control device for controlling the three-way valve as in the prior art. For this reason, a structure can be simplified. Therefore, the manufacturing cost can be reduced.

[Application Example 2] The refrigerant circuit adjustment device according to Application Example 1, wherein a circulation path for circulating a refrigerant between the fuel cell and the radiator, a radiator-side bypass flow path for bypassing the radiator, A fuel cell side bypass flow path that bypasses the radiator is provided as a flow path that constitutes the fuel cell circuit and the cooling circuit, and the first thermostat is arranged on the upstream side of the fuel cell side bypass flow path. The second thermostat is provided at a connection portion with the circulation path on the upstream side of the front radiator-side bypass flow path, and the first thermostat and the second thermostat in the circulation path are provided. The refrigerant circuit adjustment apparatus which connected the said circuit for an air conditioning between.

  According to the refrigerant circuit adjustment device described in Application Example 2, the circuit configuration can be made simple and suitable.

Application Example 3 In the refrigerant circuit adjustment device according to Application Example 1 or 2, the second temperature is a calorific value of the fuel cell when a load necessary for steady operation of the fuel cell is received. A refrigerant circuit adjustment device having a temperature determined based on

  According to the refrigerant circuit adjustment device described in Application Example 3, it is possible to prevent the state where the temperature of the refrigerant is high without continuing the second thermostat during the steady operation of the fuel cell. If the state where the refrigerant temperature is high is continued, it adversely affects the power generation state of the fuel cell, but this can be avoided.

Application Example 4 In the refrigerant circuit adjustment device according to Application Example 3, the temperature of the refrigerant flowing through the fuel cell is in a predetermined range on the high temperature side between the first temperature and the second temperature. A high temperature determination unit that determines whether or not a predetermined time has elapsed, and a load increase unit that increases the load of the fuel cell when the high temperature determination unit determines that the state has continued for a predetermined time or longer. A refrigerant circuit adjustment device comprising:

  According to the refrigerant circuit adjustment device described in the application example 4, when the temperature of the refrigerant stagnates on the high temperature side in the intermediate temperature range between the first temperature and the second temperature, the load of the fuel cell is increased. Thus, the temperature of the refrigerant can be forcibly lowered. As a result, the fuel cell can be controlled in a temperature range where the durability of the fuel cell is excellent.

[Application Example 5] The refrigerant circuit adjustment device according to Application Example 1, which is in communication with the vehicle interior, and includes a fan, an evaporator provided in a heat pump, an opening / closing shutter, and a duct portion in which the heater core for heating is disposed. Control for controlling at least one of the heater core for heating, the heat pump, and the open / close shutter based on the detected temperature of the refrigerant, and a refrigerant temperature detector that detects the temperature of the refrigerant flowing through the fuel cell. A refrigerant circuit adjusting device.

  According to the refrigerant circuit adjustment device described in Application Example 5, by controlling at least one of the heater core, the heat pump, and the open / close shutter, without being affected by the hysteresis characteristics of the first and second thermostats, The temperature of the refrigerant can be controlled.

[Application Example 6] The refrigerant circuit adjustment device according to Application Example 1, wherein the refrigerant circuit adjustment apparatus communicates with a vehicle interior, and includes a fan, an evaporator provided in a heat pump, an opening / closing shutter, and a duct portion in which the heater core for heating is disposed. A controller that controls the open / close shutter to an open state when the temperature of the refrigerant flowing through the fuel cell is within a predetermined range between the first temperature and the second temperature during cooling using the heat pump. A refrigerant circuit adjustment device comprising:

  According to the refrigerant circuit adjustment device described in Application Example 6, the refrigerant can be cooled by the cooling air of the air conditioning by controlling the open / close shutter during cooling.

Application Example 7 The refrigerant circuit adjustment device according to Application Example 1, wherein the first and second thermostats have a configuration in which a hysteresis width of the first thermostat is narrower than a hysteresis width of the second thermostat. Circuit adjustment device.

  According to the refrigerant circuit adjustment device described in Application Example 7, it is possible to increase the gap between the opening temperature of the first thermostat and the closing temperature of the second thermostat. For this reason, when the circuit is switched between the first circuit configuration and the second circuit configuration, it is possible to prevent a problem that the transition to the both is finely repeated.

  Furthermore, the present invention can be realized in various forms other than the above application examples 1 to 7. For example, the present invention can be realized in a form in which the refrigerant circuit adjustment device of the present invention is provided as a part of the vehicle control device. It is.

It is explanatory drawing which shows the structure of the refrigerant circuit adjustment apparatus 10 as one Example of this invention. 4 is an enlarged cross-sectional view of a first thermostat 34. FIG. It is explanatory drawing which shows the aspect of the independent state of a refrigerant circuit. It is explanatory drawing which shows the aspect without a radiator of the cooperation state of a refrigerant circuit. It is explanatory drawing which shows the aspect with a radiator of the cooperation state of a refrigerant circuit. It is explanatory drawing which shows operation | movement of the refrigerant circuit adjustment apparatus 10 at the time of vehicle interior heating. It is explanatory drawing which shows operation | movement of the refrigerant circuit adjustment apparatus 10 at the time of vehicle interior cooling. It is a flowchart which shows a temperature forced shift process.

  Hereinafter, embodiments of the present invention will be described based on examples with reference to the drawings.

A. Overall configuration:
FIG. 1 is an explanatory diagram showing a configuration of a refrigerant circuit adjusting device 10 as an embodiment of the present invention. The refrigerant circuit adjustment device 10 is mounted and used in an electric vehicle that uses electric power obtained from a fuel cell as driving electric power. The refrigerant circuit adjustment device 10 includes a fuel cell stack 20, a cooling system 30, an air conditioning system 100, and a control unit 200.

  The fuel cell stack 20 is a solid polymer electrolyte type fuel cell, and has a configuration in which a plurality of single cells each having a membrane electrode assembly (MEA) are stacked. Hydrogen gas as fuel gas is supplied to the fuel cell stack 20 from a hydrogen gas tank (not shown) via a fuel gas flow path 22. Further, air as an oxidant gas is supplied to the fuel cell stack 20 through an oxidant gas flow path 24 by an air compressor (not shown). In addition to the fuel gas and the oxidant gas described above, the fuel cell stack 20 is supplied with a refrigerant, and each single cell whose temperature is increased due to power generation is cooled by the refrigerant. In the present embodiment, an antifreeze liquid in which ethylene glycol or the like is added to water is used as the refrigerant, but any cooling water such as pure water can be used instead of the antifreeze liquid. Further, instead of the cooling water, a gas such as carbon dioxide may be used as the refrigerant.

  A load 60 is electrically connected to the fuel cell stack 20, and electric power generated by an electrochemical reaction in the fuel cell stack 20 is supplied to the load 60. Here, the load 60 means, for example, a drive motor for an electric vehicle (not shown), two electric fans 38 and 32, an electric heater 55, two pumps 36 and 115, and the like which will be described later.

B. Cooling system configuration:
The cooling system 30 includes a circulation circuit C1 that circulates a cooling medium (hereinafter also simply referred to as “refrigerant”), and the fuel cell stack 20 and the radiator 31 are disposed in the circulation circuit C1. In the circulation circuit C1, two bypass channels 32 and 33 that bypass the radiator 31 are provided. That is, the bypass flow paths 32 and 33 are provided in parallel with the radiator 31. Thermostats 34 and 35 are provided at the connection portions with the circulation circuit C1 on the upstream side of the bypass flow paths 32 and 33, respectively.

  Hereinafter, the bypass passage 32 provided on the side close to the fuel cell stack 20 is referred to as a “first bypass passage”, and the thermostat 34 provided in the first bypass passage 32 is referred to as a “first thermostat”. Further, the bypass flow path 33 provided on the side close to the radiator 31 is referred to as a “second bypass flow path”, and the thermostat 35 provided in the second bypass flow path 33 is referred to as a “second thermostat”. Further, the circulation circuit C1 is referred to as a “cooling circulation circuit”.

  A first electric fan 37 is arranged in the vicinity of the radiator 31. The radiator 31 cools the refrigerant sent from the fuel cell stack 20 via the cooling circuit C1 by the wind from the first electric fan 37, and releases the heat of the refrigerant to the outside of the vehicle.

  The cooling circuit C1 is provided with a first pump 36 for circulating the refrigerant. Specifically, the first pump 36 is disposed in the vicinity of the refrigerant inlet 20 a of the fuel cell stack 20. In the illustrated example, the refrigerant circulates clockwise in the drawing in the cooling circuit C1.

  Next, the structure and operation of the thermostats 34 and 35 will be described. FIG. 2 is an enlarged cross-sectional view of the first thermostat 34.

  As shown in FIG. 2, the first thermostat 34 includes a thermostat body 40 and a case 41 that houses the thermostat body 40. The case 41 is formed with first to third openings 42, 44, 46. The first opening 42 is connected to the refrigerant outlet 20b (FIG. 1) of the fuel cell stack 20 via the cooling circuit C1. The second opening 44 is connected to the first bypass channel 32 (FIG. 1). The third opening 46 is connected to the refrigerant flow path 39 (FIG. 1) on the radiator 31 side in the cooling circuit C1. That is, in the case 41, the first opening 42 serves as a refrigerant inlet, and the second opening 44 and the third opening 46 serve as outlets, respectively.

  The thermostat main body 40 is a known wax pellet type thermostat using the thermal expansion of the wax 50 enclosed in the temperature sensing part 48. The structure and operation of the thermostat body 40 will be briefly described. The temperature sensing unit 48 includes a valve 52 that seals between the first opening 42 and the third opening 46, and the first opening 42. A bypass valve 54 that seals between the second openings 44 is integrally provided. The temperature sensing portion 48, the valve 52, and the bypass valve 54 constitute a movable portion 56 that can be linearly displaced. When the movable portion 56 is driven in the left direction in the figure, the valve 52 is closed and the bypass valve 54 is opened. Conversely, when the movable portion 56 is driven rightward in the figure, the valve 52 is opened while the bypass valve 54 is closed. The movable portion 56 is normally biased by a spring 58 in the direction in which the valve 52 is closed and the bypass valve 54 is opened (left direction in the figure).

  When the temperature of the refrigerant flowing from the first opening 42 is lower than the operating temperature of the first thermostat 34 (hereinafter referred to as “first operating temperature”), the valve 52 is closed by the biasing force of the spring 58. On the other hand, the bypass valve 54 is opened. Therefore, the refrigerant that has flowed from the first opening 42 flows out to the first bypass passage 32 via the second opening 44 if the temperature is lower than the first operating temperature.

  On the other hand, when the temperature of the refrigerant flowing from the first opening 42 becomes equal to or higher than the first operating temperature, the wax 50 thermally expands, and the movable portion 56 moves in the right direction in the figure against the urging force of the spring 58. When driven, the valve 52 is opened and the bypass valve 54 is closed. Therefore, if the temperature of the refrigerant flowing in from the first opening 42 is equal to or higher than the first operating temperature, the refrigerant flows into the cooling circuit C1 (specifically, the refrigerant flow path 39) via the third opening 46. Leaked. Thus, the 1st thermostat 34 switches the refrigerant | coolant flow path between the 1st bypass flow path 32 and the cooling circuit C1 according to the temperature of a refrigerant | coolant. When the refrigerant flow path is on the first bypass flow path 32 side, it is referred to as an “off state”, and when the refrigerant flow path is on the cooling circuit C1 side, it is referred to as an “on state”. In this embodiment, the first operating temperature is set to 65 ° C., for example.

  Returning to the description of FIG. 1, when the refrigerant reaches the portion of the first thermostat 34 in the cooling circuit C1, when the temperature of the refrigerant is lower than the first operating temperature, the first thermostat 34 is turned off. The refrigerant flows through the first bypass flow path 32 (does not flow to the refrigerant flow path 39). On the other hand, when the temperature of the refrigerant is equal to or higher than the first operating temperature, the first thermostat 34 is turned on, and the refrigerant flows to the refrigerant flow path 39 via the cooling circuit C1 (to the first bypass flow path 32). Does not flow).

  The second thermostat 35 provided on the radiator 31 side has substantially the same configuration as the first thermostat 34 having the above structure, and the difference is that the operating temperature is different from the first operating temperature. The second operating temperature in the second thermostat 35 is set to 75 ° C., for example, and is higher than the first operating temperature. As a result, when the refrigerant reaches the site of the second thermostat 35 in the cooling circuit C1, when the temperature of the refrigerant is lower than the second operating temperature, the second thermostat 35 is turned off, and the refrigerant passes through the second bypass. It flows through the flow path 33 (does not flow to the radiator 31). On the other hand, when the temperature of the refrigerant is equal to or higher than the second operating temperature, the second thermostat 35 is turned on, and the refrigerant flows to the radiator 31 via the cooling circuit C1 (flows to the second bypass flow path 33). Absent).

  An FC refrigerant air-conditioning circulation circuit 160, which will be described later, is connected to the refrigerant passage 39 between the first thermostat 34 and the second thermostat 35 in the cooling circulation circuit C1.

C. Air conditioning system configuration:
The air conditioning system 100 performs air conditioning (heating or cooling) in the passenger compartment by exchanging heat between a refrigerant for air conditioning (hereinafter referred to as “air conditioning refrigerant”) and air blown into the passenger compartment. In addition, the air conditioning system 100 further heats the refrigerant between the above-described refrigerant for the fuel cell stack 20 (hereinafter referred to as “FC refrigerant”) and the air blown into the passenger compartment when heating the passenger compartment. Use exchanges. The configuration for performing heat exchange using the latter FC refrigerant will be described first.

  The air conditioning system 100 includes an FC refrigerant air conditioning circuit C2 that circulates FC refrigerant. The FC refrigerant air-conditioning circuit C2 includes two refrigerant channels 111 and 112 for FC refrigerant, and a heater core (indoor heat exchanger) 114 connected to one end 111a and 112a of each refrigerant channel 111 and 112. Is provided. The other ends 111b and 112b of the respective refrigerant flow paths 111 and 112 are connected to a refrigerant flow path 39 between the first thermostat 34 and the second thermostat 35 in the cooling circuit C1. The connection points of the other ends 111b and 112b are separated by a predetermined distance L. A second pump 115 and an electric heater 116 are arranged in the upstream refrigerant flow path 111. The second pump 115 causes the FC refrigerant to flow in the order of the refrigerant flow path 111 → the heater core 114 → the refrigerant flow path 112. As a result, the FC refrigerant heated by the waste heat of the fuel cell stack 20 flows to the heater core 114, and the heater core 114 is heated by the heat of the FC refrigerant.

  The heater core 114 is provided in the air blowing unit 120. The air blowing unit 120 includes a duct part 121 communicating with the vehicle interior, and a second electric fan 122 for generating air blown out to the vehicle interior upstream of the duct part 121. A heater core 114 is disposed in the internal space 130 of the duct portion 121. Thereby, the air warmed by the heater core 114 passes through the duct portion 121, and warm air is sent from various outlets (ventilator, foot, defroster, etc.) connected to the duct portion 121.

  The flow of the FC refrigerant to the FC refrigerant air-conditioning circulation circuit C <b> 2 is on / off controlled by the first thermostat 34. That is, when the first thermostat 34 is in the OFF state, the FC refrigerant does not flow to the FC refrigerant air-conditioning circuit C2, and when the first thermostat 34 is in the ON state, the FC refrigerant flows to the FC refrigerant air-conditioning circuit C2. . When the first thermostat 34 is in the ON state, the FC refrigerant flows in the direction toward the second thermostat 35 by going straight through the cooling circuit C1 as well as the FC refrigerant air-conditioning circuit C2.

  When the first thermostat 34 is in the OFF state, the FC refrigerant circulates in the order of the refrigerant flow path 111 → the refrigerant flow path 112 → the refrigerant flow path 39 in the circulation circuit C2 for FC refrigerant air conditioning. As a result, as shown in FIG. 3, when the temperature TW of the FC refrigerant is lower than the first operating temperature T1 and the first thermostat 34 is in the OFF state, the fuel cell stack 20 and the first bypass flow path 32 A circulation path circulating between them and a circulation path such as the refrigerant flow path 111 → the refrigerant flow path 112 → the refrigerant flow path 39 on the FC refrigerant air-conditioning circulation circuit C2 side exist individually. In other words, when the temperature TW of the FC refrigerant is lower than the first operating temperature T1, the cooling circuit C1 and the FC refrigerant air-conditioning circuit C2 are not connected to each other.

  On the other hand, when the temperature TW of the FC refrigerant is equal to or higher than the first operating temperature T1, the first thermostat 34 is turned on, so that the FC refrigerant flows to the FC refrigerant air conditioning circuit C2 as shown in FIG. Then, the cooling circuit C1 and the FC refrigerant air-conditioning circuit C2 are connected to each other. Note that the flow state of the FC refrigerant in FIG. 4 is the case when the temperature TW of the FC refrigerant is equal to or higher than the first operating temperature T1 and lower than the second operating temperature T2. In this case, the FC refrigerant passes through the second bypass flow path 33 and bypasses the radiator 31 in the FC refrigerant air-conditioning circulation circuit C2. The state of FIG. 4 corresponds to the “first circuit configuration” described in application example 1.

  When the temperature TW of the FC refrigerant is equal to or higher than the second operating temperature T2 that is higher than the first operating temperature T1, both the first thermostat 34 and the second thermostat 35 are turned on, as shown in FIG. The cooling circuit C1 and the FC refrigerant air-conditioning circuit C2 are connected to each other, and the FC refrigerant circulates through the radiator 31 in the FC refrigerant air-conditioning circuit C2. The state of FIG. 5 corresponds to the “second circuit configuration” described in application example 1.

  Considering the degree of cooling of the FC refrigerant, in the independent state shown in FIG. 3, the FC refrigerant discharged from the fuel cell stack 20 only circulates through the first bypass flow path 32. The degree is extremely low. On the other hand, in the cooperative state shown in FIG. 4, the FC refrigerant discharged from the fuel cell stack 20 is cooled by the heater core 114, so the degree of cooling of the FC refrigerant is large. In the cooperative state shown in FIG. 5, the FC refrigerant discharged from the fuel cell stack 20 is cooled by the heater core 114, and further circulates through the radiator 31, so that the degree of cooling of the FC refrigerant is greater than in the case of FIG. . That is, the degree of cooling of the FC medium increases in the order of FIG. 3, FIG. 4, and FIG.

  Returning to FIG. 1, as described above, the air conditioning system 100 includes a configuration for performing heat exchange using the air conditioning refrigerant in addition to the FC refrigerant air conditioning circulation circuit C2. This configuration will be described next.

  The air conditioning system 100 includes an air conditioning refrigerant air conditioning circulation circuit 140 that circulates the air conditioning refrigerant. In the circulation circuit 140 for air conditioning refrigerant air conditioning, an evaporator (evaporator) 141, an indoor condenser 142, and an outdoor heat exchanger 143 are arranged in this order. An air conditioner compressor 145 is disposed in the refrigerant flow path 151 connecting the evaporator 141 and the indoor condenser 142, and a three-way valve 146 is disposed in the refrigerant flow path 152 connecting the indoor condenser 142 and the outdoor heat exchanger 143. An open / close valve 147 and an expansion valve 148 are arranged in the refrigerant flow path 153 connecting the heat exchanger 143 and the evaporator 141.

  The outdoor heat exchanger 143 and the open / close valve 147 branch to a refrigerant flow path 154, and the refrigerant flow path 156 is connected to the three-way valve 146. An expansion valve 149 is provided in the refrigerant flow path 154. The outdoor heat exchanger 143 and the three-way valve 146 branch to a refrigerant flow path 155, and the refrigerant flow path 155 is connected to a refrigerant flow path 156 that connects the evaporator 141 and the air conditioner compressor 145. An opening / closing valve 158 is provided in the refrigerant flow path 155.

  The evaporator 141 is provided between the second electric fan 122 and the heater core 114 in the internal space 130 of the duct part 121 of the blower part 120. The evaporator 141 cools the air by performing heat exchange with the air from the second electric fan 122 during cooling. The indoor condenser 142 is provided further downstream from the heater core (indoor heat exchanger) 114 in the internal space 130. The indoor condenser 142 raises the temperature of the blown air by exchanging heat with the blown air from the second electric fan 122 during heating. The outdoor heat exchanger 143 is provided at the front portion of the vehicle so as to be able to come into contact with the outside air, and exchanges heat between the air-conditioning refrigerant that has flowed into the outside air.

  The air conditioner compressor 145 compresses the air conditioning refrigerant to a high temperature and high pressure state. Each of the first and second expansion valves 148 and 149 adiabatically expands the air-conditioning refrigerant and injects it into the evaporator 141 or the outdoor heat exchanger 143 in a low temperature / low pressure mist state. The three-way valve 146 and the two on-off valves 147 and 158 are valves for controlling the flow of the air-conditioning refrigerant.

  A roll-type opening / closing shutter 161 is provided in front of the heater core 114 (in the upstream direction) in the internal space 130 of the duct portion 121 of the blower portion 120. A wing-type opening / closing shutter 162 is provided in front of the indoor condenser 142.

  In the air conditioning system 100, a so-called heat pump is configured, and the opening and closing of the valves 146, 147, 158 is adjusted, whereby the flow of the air conditioning refrigerant in the air conditioning refrigerant air conditioning circulation circuit 140 during the heating operation and the cooling operation. Is switched. Further, by adjusting the opening / closing of the opening / closing shutters 161 and 162, the air blowing to the heater core 114 and the indoor condenser 142 is executed / stopped.

D. Control unit configuration:
The control unit 200 is a so-called computer that controls the operation of the cooling system 30 and the air conditioning system 100, and mainly includes a CPU (Central Processing Unit), a memory 202, and an input / output circuit 203. The input / output circuit 203 connects various sensors, various switches, and various actuators via control signal lines (not shown).

  Various sensors include various temperature sensors, voltage sensors (not shown), current sensors (not shown), and the like. In the present embodiment, a first temperature sensor 61 provided at the refrigerant inlet 20a of the fuel cell stack 20, a second temperature sensor 62 provided at the refrigerant outlet 20b of the fuel cell stack 20, and an in-vehicle temperature sensor (not shown). A vehicle exterior temperature sensor (not shown), a solar radiation amount sensor (not shown), etc. are provided as various temperature sensors. As various switches, an operation panel (not shown) including a switch for designating a set temperature of the air conditioner is provided.

  The various actuators include a first electric fan 37 and a first pump 36 provided in the cooling system 30, an electric heater 116 and a second pump 115 provided in the air conditioning system 100, valves 146, 147 and 158, an air conditioner. There are a compressor 145, a second electric fan 122, open / close shutters 161, 162, and the like.

  The memory 202 stores a computer program (not shown) mainly for controlling the cooling system 30 and the air conditioning system 100, and the CPU 201 executes the computer program to detect the detection values of various sensors and the output of the operation panel. Various actuators are driven based on signals and the like to control the temperature of the FC refrigerant and the temperature in the passenger compartment.

E. Operation of each part:
Next, the operation of the refrigerant circuit adjustment device 10 configured as described above will be described. FIG. 6 is an explanatory diagram showing the operation of the refrigerant circuit adjustment device 10 during vehicle interior heating. FIG. 7 is an explanatory diagram showing the operation of the refrigerant circuit adjustment device 10 during cooling of the passenger compartment. 6 and 7, the horizontal axis indicates the temperature of the FC refrigerant. The vertical axis shows (1) the connection mode between the cooling circuit C1 and the FC refrigerant air conditioning circuit 160, (2) the amount of heat generated by the fuel cell stack 20, (3) the power consumption of the electric heater 116, (4 ) Power consumption of heat exchange (heat pump) using air conditioning refrigerant in the air conditioning system 100, (5) Open / close position of the open / close shutter 161 provided in the heater core 114, (6) Open / close of the first and second thermostats 34, 35 Has been taken.

  As shown in (6) of both drawings, the first and second thermostats 34 and 35 have a property that the opening / closing timing has hysteresis. As described above, the first thermostat 34 is turned on when the temperature TW of the FC refrigerant is equal to or higher than the first operating temperature T1 (hereinafter also referred to as “first opening temperature”), and the first opening temperature. When the temperature is equal to or lower than the first closing temperature T3 lower than T1, it is turned off. As described above, the second thermostat 35 is turned on when the temperature TW of the FC refrigerant is equal to or higher than the second operating temperature T2 (hereinafter referred to as “second opening temperature”), and the second opening temperature. When the temperature is equal to or lower than the second closing temperature T4 lower than T2, it is turned off. In this embodiment, the hysteresis width (= T1-T3) of the first thermostat 34 is narrower than the hysteresis width (= T2-T4) of the second thermostat 35.

  When the first and second thermostats 34 and 35 are opened and closed, as shown in (1) of both figures, the connection mode between the cooling circuit C1 and the FC refrigerant air-conditioning circuit 160 depends on the temperature of the FC refrigerant. In response to the rise, the state shifts in turn to an independent state, a state of cooperation and bypassing the radiator, and a state of cooperation and passage through the radiator.

  During heating, the electric heater 116 and the heat pump are controlled as shown in (3) and (4) of FIG. That is, when the temperature of the FC refrigerant is as low as 60 [° C.], for example, the electric heater 116 and the heat pump are driven with high electric power. When the temperature of the FC refrigerant reaches a predetermined temperature in the vicinity of the first closing temperature T3, each power consumption of the electric heater 116 and the heat pump starts to decrease, and each power consumption gradually decreases as the temperature of the FC refrigerant increases. When the temperature of the FC refrigerant reaches a predetermined temperature in the vicinity of the first open temperature T1, each power consumption has a value of zero. Each predetermined temperature in the vicinity is not limited to the vicinity, and may be a temperature that matches the first closing temperature T3 or the first opening temperature T1. The open / close shutter 161 provided in the heater core 114 is controlled to be open regardless of the temperature of the FC refrigerant, as shown in (5) of FIG.

  The reason for controlling the electric heater 116 and the heat pump as described above is that the heater core 114 is heated by driving the electric heater 116 because it is in an independent state when the temperature of the FC refrigerant is low. When the temperature TW of the FC refrigerant becomes higher than the first opening temperature T1, the electric heater 116 is turned off because the waste heat of the fuel cell stack 20 can be used for the heater core 114 in a linked state. . Since the vehicle interior can be sufficiently heated by the heater core 114, the heat pump is turned off.

  Note that the heat generation amount (FC heat generation amount) of the fuel cell stack 20 is proportional to the temperature of the FC refrigerant, as shown in (2) of FIG. A two-dot chain line in the figure indicates the calorific value LC of the fuel cell stack 20 when the fuel cell stack 20 receives a load during steady operation. Here, the “load during steady operation” is a load necessary for the vehicle to travel on a flat ground with a gradient of 0% at a steady travel speed of 60 km / h. In the present embodiment, as shown in FIG. 6, the second open temperature T2 for the second thermostat 35 is set to the temperature of the FC refrigerant when the FC heat generation amount matches the heat generation amount LC. In addition, it does not completely coincide with each other and may be a temperature in the vicinity of the second open temperature T2.

  On the other hand, at the time of cooling, as shown in (3) of FIG. 7, the electric heater 116 is turned off. As shown in (4) of FIG. 7, the heat pump is driven with large power consumption for cooling.

  The opening / closing shutter 161 provided in the heater core 114 is controlled to open / close according to the temperature of the FC refrigerant, as shown in FIG. That is, when the temperature of the FC refrigerant is as low as 60 [° C.], for example, it is in the closed state because it is during cooling. When the temperature of the FC refrigerant reaches a predetermined temperature in the vicinity of the first closing temperature T3, the open / close shutter 161 starts to open, and the opening degree increases as the temperature of the FC refrigerant increases, and the fully open state is reached. Further, when the temperature of the FC refrigerant rises, the opening / closing shutter 161 starts to close, and the opening degree decreases as the temperature of the FC refrigerant rises, and the temperature TW of the FC refrigerant becomes a predetermined temperature in the vicinity of the first opening temperature T1. Sometimes it becomes fully closed. Each predetermined temperature in the vicinity is not limited to the vicinity, and may be a temperature that matches the first closing temperature T3 or the first opening temperature T1.

  By opening the opening / closing shutter 161 between the first closing temperature T3 and the first opening temperature T1 as described above, the FC refrigerant can be cooled by the cooling air of the air conditioning in the linked state. Note that when the first open temperature T1 is exceeded, the radiator 31 can be used even in the linked state, and therefore the air-conditioning cooling air is unnecessary, and the open / close shutter 161 is fully closed. As a modification, the open / close shutter 161 may be configured to fully open in the entire region between the first closing temperature T3 and the first opening temperature T1.

  As described above, by controlling the electric heater 116, the heat pump, and the open / close shutter 161 by the control unit 200, the temperature of the refrigerant in the fuel cell stack 20 is controlled to the appropriate control range ZC during heating and cooling. Can do. In particular, the first and second thermostats 34 and 35 have a property having hysteresis as described above. However, according to the configuration, the temperature of the refrigerant is controlled within the proper control range ZC without being affected by the hysteresis property. can do. In general, the fuel cell stack 20 is superior in terms of power generation efficiency at a temperature slightly higher than the illustrated appropriate control range ZC. However, when the durability of the fuel cell stack 20 is considered, the fuel cell stack 20 is controlled within the appropriate control range ZC. It is preferable to do. For this reason, the present Example D can improve the durability of the fuel cell stack 20.

  Further, in this embodiment, the control unit 200 performs the following temperature forced shift process. FIG. 8 is a flowchart showing the temperature forced shift process. As shown in the figure, the CPU of the control unit 200 takes in the temperature TW of the FC refrigerant detected by the second temperature sensor 62 (step S110), and the state where the FC refrigerant temperature TW is within a predetermined high temperature range is predetermined. It is determined whether or not it has continued for more than the time (step S120). The “predetermined high temperature range” is a predetermined range on the high temperature side between the first open temperature T1 and the second open temperature T2 (medium temperature range), and is set to 70 to 75 ° C. in this embodiment. ing. In addition, it is not necessary to limit to 70-75 degreeC, and any range may be sufficient if an upper limit is the 2nd open temperature T2 side.

  If it is determined in step S120 that the state where the FC refrigerant temperature TW is within the predetermined high temperature range has continued for a predetermined time or longer, processing for increasing the load on the fuel cell stack 20 is performed (step S130). The load is preferably a load excluding a drive motor that affects the running of the vehicle among various loads 60 connected to the fuel cell stack 20, for example, driving of an air compressor for supplying oxidant gas (not shown) Increase power. When the load 60 is increased, the FC refrigerant temperature TW rises, so that the connection form is switched to the cooperative state using the radiator, and the radiator 31 is used to ensure that the FC refrigerant temperature TW is within the proper control range ZC. Can be lowered.

  After the execution of step S130 or when a negative determination is made in step S120, this temperature forced shift process ends.

  According to the temperature forced shift process having such a configuration, when the temperature of the FC refrigerant stagnates on the high temperature side in the middle temperature range between the first open temperature T1 and the second open temperature T2, the fuel cell stack 20 As a result, the temperature of the FC refrigerant can be forcibly lowered. As a result, the fuel cell stack 20 can be controlled in a temperature range where the durability of the fuel cell stack 20 is excellent. Further, if the driving force of the air compressor is increased as the load increases, the gas pressure in the oxidant gas flow path increases, so that the amount of water carried away in the fuel cell stack 20 is reduced when the water temperature rises, and the fuel cell There is also a role of keeping the moisture content of the stack 20 constant.

F. Example effect:
According to the refrigerant circuit adjusting apparatus 10 of the above-described embodiment configured as described above, the FC refrigerant is cooled by using the FC refrigerant air-conditioning circulation circuit C2, and the FC refrigerant is cooled by the FC. The first and second thermostats 34 and 35 can perform circuit switching between the second circuit configuration performed using the refrigerant air-conditioning circulation circuit C2 and the radiator 31. Since the thermostat automatically switches the flow path according to the temperature, it does not require a three-way valve or a control device for controlling the three-way valve as in the prior art. For this reason, the refrigerant circuit adjustment device 10 of the first embodiment can be simplified in configuration. Therefore, the manufacturing cost can be reduced.

  Further, according to the refrigerant circuit adjusting apparatus 10 of the embodiment, the operating temperature T2 of the second thermostat 35 is based on the calorific value LC of the fuel cell stack 20 when the fuel cell stack 20 receives a load during steady operation. Since the predetermined temperature is reached, it is possible to prevent the second thermostat 35 from being opened during the steady operation of the fuel cell stack 20 and the high FC refrigerant temperature from being continued. If the state where the refrigerant temperature is high is continued, the power generation state of the fuel cell stack 20 is adversely affected, but this can be avoided.

  Furthermore, according to the refrigerant circuit adjusting apparatus 10 of the above embodiment, the hysteresis width of the first thermostat 34 is narrower than the hysteresis width of the second thermostat 35, so that the hysteresis width of the first thermostat 34 can be set small. it can. For this reason, as shown in FIGS. 6 and 7, the gap between the second closing temperature T4 and the first opening temperature T1 can be widened. When the gap between the second closing temperature T4 and the first opening temperature T1 is narrow, the circuit is switched between the circuit configuration of FIG. 4 without a radiator in cooperation and the circuit configuration of FIG. 5 with a radiator in cooperation. At this time, there is a possibility that a problem that the transition to both is repeated finely can be prevented.

G. Variations:
The present invention is not limited to the above-described embodiments and modifications thereof, and can be carried out in various modes without departing from the gist thereof. For example, the following modifications are possible. .

・ First modification:
In the above-described embodiments and modifications thereof, the coolant temperature of the fuel cell stack 20 is set as the detection value of the second temperature sensor 62 provided at the refrigerant outlet 20b of the fuel cell stack 20, but it is not necessarily limited to this. For example, the detected value of the first temperature sensor 61 provided at the refrigerant inlet 20a of the fuel cell stack 20 may be used, and any parameter corresponding to the temperature of the FC refrigerant can be used.

・ Second modification:
Although the control unit 200 is used for both the cooling system 30 and the air conditioning system 100 in the above-described embodiment and its modifications, each control unit 200 may be configured by an individual control unit. In this case, it is preferable to adopt a configuration in which necessary information (such as a detection value of the second temperature sensor 62) is communicated between the control units.

・ Third modification:
In the above-described embodiments and modifications thereof, the refrigerant circuit adjustment device 10 is used by being mounted on an electric vehicle. However, instead, the refrigerant circuit adjustment device 10 may be configured to be mounted on another vehicle such as a hybrid vehicle.

-Fourth modification:
In the above-described embodiments and modifications thereof, a polymer electrolyte fuel cell is used as the fuel cell stack 20, but various fuel cells such as a phosphoric acid fuel cell, a molten carbonate fuel cell, and a solid oxide fuel cell are used. Can be used.

-5th modification:
In the above-described embodiments and modifications thereof, a part of the configuration realized by software may be replaced with hardware. On the contrary, a part of the configuration realized by hardware may be replaced with software.

  It should be noted that elements other than those described in the independent claims among the constituent elements in each of the above-described embodiments and modifications are additional elements and can be omitted as appropriate.

DESCRIPTION OF SYMBOLS 10 ... Refrigerant circuit adjustment apparatus 20 ... Fuel cell stack 20a ... Refrigerant inflow port 20b ... Refrigerant outflow port 22 ... Fuel gas flow path 24 ... Oxidant gas flow path 30 ... Cooling system 31 ... Radiator 32 ... 1st bypass flow path 33 ... 2nd bypass flow path 34 ... 1st thermostat 35 ... 2nd thermostat 36 ... 1st pump 37 ... 1st electric fan 39 ... Refrigerant flow path 40 ... Thermostat main body 41 ... Case 42 ... 1st opening part 44 ... 2nd Opening 46 ... Third opening 48 ... Temperature sensing unit 50 ... Wax 52 ... Valve 54 ... Bypass valve 55 ... Electric heater 56 ... Moving part 58 ... Spring 61 ... First temperature sensor 62 ... Second temperature sensor 100 ... Air conditioning System 111 ... Refrigerant flow path 112 ... Refrigerant flow path 114 ... Heater core 115 ... Second pump 116 ... Electric heater 120 ... Air blower 1 DESCRIPTION OF SYMBOLS 1 ... Duct part 122 ... 2nd electric fan 130 ... Internal space 140 ... Circulation circuit for air-conditioning refrigerant air-conditioning 141 ... Evaporator 142 ... Indoor condenser 143 ... Outdoor heat exchanger 145 ... Air-conditioner compressor 146 ... Three-way valve 147 ... Open / close valve 148 ... First 1 expansion valve 149 ... 2nd expansion valve 151 ... refrigerant flow path 152 ... refrigerant flow path 153 ... refrigerant flow path 154 ... refrigerant flow path 155 ... refrigerant flow path 156 ... refrigerant flow path 158 ... open / close valve 161 ... open / close shutter 162 ... Opening / closing shutter 200 ... Control unit 201 ... CPU
202 ... Memory 203 ... I / O circuit C1 ... Cooling circuit T1 ... First operating temperature T2 ... Second operating temperature

Claims (7)

A refrigerant circuit adjustment device mounted on a vehicle including a fuel cell,
A circuit through which a refrigerant flows, and a fuel cell circuit in which the fuel cell is disposed;
A circuit through which a refrigerant flows, and a cooling circuit in which a radiator is disposed;
A circuit through which the refrigerant flows, and an air conditioning circuit in which a heater core for heating the vehicle interior is disposed;
Between a plurality of circuit configurations including at least a first circuit configuration in which the fuel cell circuit and the air conditioning circuit are connected and a second circuit configuration in which the cooling circuit is further connected to the first circuit configuration. And a circuit switching unit for switching circuits,
The circuit switching unit is
A first thermostat for switching the circuit to the first circuit configuration by switching the flow path when the temperature of the refrigerant becomes equal to or higher than the first temperature;
A refrigerant circuit adjustment device comprising: a second thermostat for switching the circuit to the second circuit form by switching the flow path when the temperature of the refrigerant becomes equal to or higher than a second temperature higher than the first temperature. The refrigerant circuit adjusting device according to claim 1,
A circulation path for circulating a refrigerant between the fuel cell and the radiator;
A radiator-side bypass flow path for bypassing the radiator;
A fuel cell-side bypass flow path that bypasses the radiator, as a flow path constituting the fuel cell circuit and the cooling circuit,
The first thermostat is provided at a connection portion with the circulation path on the upstream side of the fuel cell side bypass flow path,
The second thermostat is provided at a connection portion with the circulation path on the upstream side of the front radiator side bypass flow path,
The refrigerant circuit adjustment apparatus which connected the said circuit for an air conditioning between the said 1st thermostat and the said 2nd thermostat in the said circulation path. The refrigerant circuit adjustment device according to claim 1 or 2,
The refrigerant circuit adjustment device, wherein the second temperature is a temperature determined based on a calorific value of the fuel cell when receiving a load necessary for steady operation of the fuel cell. The refrigerant circuit adjustment device according to claim 3,
A high temperature determination unit that determines whether or not the state in which the temperature of the refrigerant flowing through the fuel cell is within a predetermined range on the high temperature side between the first temperature and the second temperature continues for a predetermined time;
A refrigerant circuit adjusting device comprising: a load increasing unit that increases the load of the fuel cell when the high temperature determining unit determines that the state has continued for a predetermined time or more. The refrigerant circuit adjustment device according to any one of claims 1 to 4,
While communicating with the passenger compartment, a fan, an evaporator provided in a heat pump, an opening / closing shutter, a duct portion in which the heater core for heating is disposed,
A refrigerant temperature detector for detecting the temperature of the refrigerant flowing through the fuel cell;
A refrigerant circuit adjustment device comprising: a control unit that controls at least one of the heater core for heating, a heat pump, and an open / close shutter based on the detected temperature of the refrigerant. The refrigerant circuit adjusting device according to any one of claims 1 to 5,
While communicating with the passenger compartment, a fan, an evaporator provided in a heat pump, an opening / closing shutter, a duct portion in which the heater core for heating is disposed,
A controller that controls the open / close shutter to an open state when the temperature of the refrigerant flowing through the fuel cell is within a predetermined range between the first temperature and the second temperature during cooling using the heat pump. A refrigerant circuit adjustment device comprising: The refrigerant circuit adjusting device according to any one of claims 1 to 6,
The first and second thermostats are:
The refrigerant circuit adjustment device, wherein the hysteresis width of the first thermostat is narrower than the hysteresis width of the second thermostat.

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