JP6117664B2 - Temperature control device and temperature control method - Google Patents

Description

  The present invention relates to temperature control.

  Air conditioning and fuel cell temperature control are suitably performed by opening or shutting off the connection flow path between the hot water flow path for air conditioning and the cooling water flow path for fuel cells depending on the situation. A technique aimed at implementation is known (for example, Patent Document 1).

JP2013-014268A

  The problem of the above prior art is that there is room for improvement in mitigating the influence on the operation of the fuel cell when the air conditioning equipment fails. In addition, downsizing of the apparatus, cost reduction, resource saving, ease of manufacture, improvement in usability, and the like have been desired.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) According to one form of this invention, a temperature control apparatus is provided. The temperature control device includes: a cooling unit that circulates a heat medium to control the temperature of the fuel cell; an air conditioning unit that circulates the heat medium for air conditioning; and a heat medium that is provided between the cooling unit and the air conditioning unit. A valve for selecting one of a non-connected state in which each of them circulates and a connected state in which at least a part of the heat medium circulating in the cooling unit circulates in the air-conditioning unit; A control unit that controls heat radiation from the heat medium circulating in the air conditioning unit for temperature control of the fuel cell when the unconnected state cannot be selected. According to this aspect, even when the unconnected state cannot be selected, the temperature control of the fuel cell can be appropriately executed.

(2) In the above aspect, the control unit realizes the control of the heat radiation by controlling the flow rate of the heat medium in the air conditioning unit. According to this form, it becomes easy to control the air conditioning while controlling the heat radiation from the air conditioning unit. This is because the amount of heat supplied to the air conditioning unit via the heat medium can be controlled according to this embodiment.

(3) In the above aspect, when the control unit executes control to change the degree of opening and closing of the valve, when the temperature variation of the heat medium measured in the air conditioning unit is smaller than a predetermined value, the valve It is estimated that a failure occurred. According to this embodiment, a valve failure can be detected by a simple method.

(4) In the above aspect, the control unit estimates the failure mode of the valve based on a state of temperature control of the heat medium. According to this embodiment, the failure symptom can be estimated by a simple method.

(5) In the above aspect, the air conditioning unit includes a heater that heats a heat medium; and the control unit controls the valve when it is detected that the heater cannot exhibit a predetermined heat generation capability. To set the connected state. According to this aspect, even when the heater cannot exhibit heat generation capability, air conditioning can be realized by supplying waste heat from the fuel cell to the air conditioning unit.

(6) In the above aspect, the control unit performs the detection based on the fact that power consumption by the heater is small with respect to the duty of the heater. According to this embodiment, the failure mode of the heater can be estimated by a simple method.

(7) In the above aspect, when the temperature of the fuel cell does not decrease to a target value due to the control of the cooling unit, the control unit controls the air conditioning as the control of the heat radiation amount according to the temperature of the fuel cell. For this reason, the air conditioning unit is caused to perform heat radiation that is greater than the heat radiation amount. According to this aspect, when the temperature of the fuel cell is not lowered to the target value depending on the control of the cooling unit, the air conditioning unit performs heat radiation that is larger than the heat radiation amount for air conditioning. It becomes easy to control the temperature to the target value.

  The present invention can be realized in various forms other than the above. For example, it can be realized in the form of a temperature control method, a program for realizing the method, a non-temporary storage medium storing the program, and the like.

The block diagram of a temperature control system. The figure which shows the flow of the cooling water and warm water in a non-connecting state. The figure which shows the flow of the cooling water and warm water in a connection state. The table which shows the estimation method of the failure mode of an electric heater. The table which shows the estimation method of the failure mode of a three-way valve. A table showing actions when a failure occurs.

  FIG. 1 is a configuration diagram of the temperature control system 1. The temperature control system 1 is mounted on a fuel cell vehicle. As shown in FIG. 1, the temperature control system 1 includes a cooling unit 10, an air conditioning unit 20, a fuel cell ECU (Electronic Control Unit) 31, an air conditioning ECU 32, a fuel cell stack 100, and a first connection. A channel 216 and a second connecting channel 218 are provided.

  The fuel cell stack 100 is constituted by a polymer electrolyte fuel cell. The electric power generated by the fuel cell stack 100 is supplied to an automobile drive motor, secondary battery, auxiliary equipment, and the like. The auxiliary devices are, for example, pumps WP1 and WP2, a fan 112, a blower 220, and an electric heater 202, which will be described later.

  The cooling unit 10 includes a cooling channel 120, a pump WP1, a temperature sensor 130, a fuel cell stack 100, a temperature sensor 132, a radiator 110, a fan 112, a three-way valve V1, and a bypass 128. .

  The cooling channel 120 is a channel for circulating cooling water. The pump WP1 circulates cooling water. The coolant passes through the fuel cell stack 100 after flowing out of the pump WP1. The temperature sensor 130 measures the temperature of cooling water flowing into the fuel cell stack 100 (hereinafter referred to as “FC inlet temperature”). The temperature sensor 132 measures the temperature of the cooling water that has flowed out of the fuel cell stack 100.

  The cooling water flowing out of the fuel cell stack 100 passes through the radiator 110 or the bypass 128 and returns to the pump WP1. Which is passed is determined by opening and closing the three-way valve V1. The fan 112 promotes heat dissipation from the cooling water passing through the radiator 110 by sending air to the radiator 110.

  There are cases where the cooling water flowing out from the fuel cell stack 100 circulates only through the cooling flow path 120 and passes through the air conditioning flow path 210 before reaching the radiator 110 or the bypass 128. Which case is to be determined is determined by opening and closing the three-way valve V2 (detailed together with FIGS. 2 and 3). The first connection channel 216 and the second connection channel 218 are provided with the cooling channel 120 and the air conditioning channel 210 when the cooling water flowing out from the fuel cell stack 100 passes through the air conditioning channel 210. Functions as a flow path connecting the two.

  The fuel cell ECU 31 controls the FC inlet temperature by controlling the opening and closing of the three-way valve V1 and the rotational speed of the fan 112 based on the measured values of the temperature sensors 130 and 132.

  The air conditioning unit 20 includes an air conditioning channel 210, a pump WP2, a temperature sensor 230, an electric heater 202, a heater core 200, a blower 220, a ventilation duct 24, a temperature sensor 232, and a three-way valve V2. Prepare.

  The air conditioning channel 210 is a channel for circulating hot water. The pump WP2 circulates hot water. The hot water flowing out from the pump WP2 is heated by the electric heater 202. The heated hot water passes through the heater core 200. The temperature sensor 230 measures the temperature of hot water flowing into the heater core 200 (hereinafter referred to as “heater core inlet temperature”). The temperature sensor 232 measures the temperature of hot water flowing out from the 200. The blower 220 blows air toward the vehicle interior via the ventilation duct 24. The blown air passes through the heater core 200 and is heated.

  The hot water flowing out of the heater core 200 circulates only through the air conditioning channel 210 or passes through a part of the cooling channel 120 and returns to the pump WP2. Which state is reached is determined by opening and closing of the three-way valve V2 (detailed together with FIGS. 2 and 3). The three-way valve V2 connects the first connection channel 216 and the air conditioning channel 210.

  The air conditioning ECU 32 determines the duty of the electric heater 202, the rotational speed of the blower 220, the opening and closing of the three-way valve V2, the cooling device (for refrigerant) according to the target passenger compartment temperature, the current passenger compartment temperature, the current outside air temperature, and the like. , Etc. (not shown). The duty is the ratio of the time during which current flows through the electric heater 202 in one cycle in the pulse width modulation control. As a result, the amount of heat released from the heater core 200 and the blowing temperature are controlled. The heat radiation from the heater core 200 is used in air conditioning modes such as cooling and defrosting in addition to heating.

  FIG. 2 shows the flow of cooling water and hot water in a disconnected state. The unconnected state is realized by closing the three-way valve V2. In the disconnected state, the cooling water circulates only through the cooling unit 10, and the hot water circulates only through the air conditioning unit 20. Therefore, temperature control is performed in each of the cooling unit 10 and the air conditioning unit 20.

  FIG. 3 shows the flow of the heat medium in the connected state. A heat medium here is a general term for cooling water and warm water. The cooling water and the hot water are the same substance, and are distinguished from each other based on the use in the unconnected state.

  In the connected state, the first connection channel 216 functions as a channel for drawing the heat medium flowing out from the fuel cell stack 100 into the air conditioning unit 20. In the connected state, the second connection channel 218 functions as a channel for allowing the heat medium flowing out from the heater core 200 to flow into the radiator 110 or the bypass 128. As a result, the heat medium circulates between the cooling unit 10 and the air conditioning unit 20. In the connected state, waste heat from the fuel cell stack 100 is used for air conditioning in the passenger compartment.

  The fuel cell ECU 31 determines whether or not to permit the connection state based on the FC inlet temperature, the state of heat radiation from the radiator 110, and the like, and transmits it to the air conditioning ECU 32 by communication. The air conditioning ECU 32 closes the three-way valve V2 when the connected state is not permitted by the fuel cell ECU 31. The air conditioning ECU 32 determines whether the three-way valve V2 is opened or closed when the connected state is permitted by the fuel cell ECU 31. This determination is performed based on a control method that takes into account the stability and responsiveness of the temperature control of the cooling water, or fuel consumption.

FIG. 4 is a table showing a method for estimating the failure mode of the electric heater 202. As shown in FIG. 4, the air conditioning ECU 32 estimates that the electric heater 202 can no longer generate heat when the power consumption of the electric heater 202 is too small with respect to the duty of the electric heater 202. The air conditioning ECU 32 calculates the power consumption of the electric heater 202 based on the current value flowing through the electric heater 202 and the resistance value of the electric heater 202. The value of current flowing through the electric heater 202 is measured by an ammeter (not shown) installed in the electric heater 202.
Hereinafter, this failure is referred to as “OFF failure”. The air conditioning ECU 32 estimates that the heat generation of the electric heater 202 cannot be stopped when the power consumption of the electric heater 202 is too large for the duty of the electric heater 202. Hereinafter, this failure is referred to as “ON failure”. Specific numerical values for the duty and the power consumption are determined by experiments and stored in the air conditioning ECU 32. The same applies to other parameters used for estimation described later.

  FIG. 5 is a table showing a method for estimating the failure mode of the three-way valve V2. The air conditioning ECU 32 estimates that a failure has occurred in the three-way valve V2 when the heater core inlet temperature hardly fluctuates despite the output of a control signal for changing the open / close state of the three-way valve V2. For example, if the change in the heater core inlet temperature is equal to or less than a predetermined value at the elapse of a predetermined time from the output of the control signal, it is determined that “the heater core inlet temperature hardly changes”.

  When detecting this symptom, the air conditioning ECU 32 determines the failure mode of the three-way valve V2 based on the failure mode of the electric heater 202 and the control state of the heat medium. The air conditioning ECU 32 acquires the control state of the coolant temperature from the fuel cell ECU 31 by communication.

  As shown in FIG. 5A, when the FC inlet temperature can be controlled normally when the electric heater 202 is normal, the air conditioning ECU 32 estimates that the three-way valve V2 is closed and cannot be opened. Hereinafter, this failure is referred to as “closed failure”. The reason for this estimation is that the temperature control system 1 is designed on the assumption that normal temperature control can be performed with the three-way valve V2 closed.

  As shown in FIG. 5B, when the electric heater 202 is normal and the FC inlet temperature cannot be controlled normally (for example, when the temperature lower than the target temperature continues), the air conditioning ECU 32 is in three directions. It is presumed that the valve V2 remains open and cannot be closed. Hereinafter, this failure is referred to as “open failure”. The reason for this estimation is that the heat that should be used to maintain the FC inlet temperature by selecting the disconnected state is considered to be dissipated from the heater core 200 and used for air conditioning.

  As shown in FIG. 5C, in the case of an OFF failure, when the heater core inlet temperature falls rapidly without being controlled, the air conditioning ECU 32 estimates that a closing failure has occurred. This is because the rapid drop in the heater core inlet temperature suggests that the hot water is hardly heated.

  As shown in FIG. 5D, in the case of an OFF failure, when the FC inlet temperature and the heater core inlet temperature cannot be normally controlled (when at least one of the temperatures lower than the target temperature continues), The air conditioning ECU 32 estimates that an open failure has occurred. In the case of an open failure, since the heat medium heated by the fuel cell stack 100 flows into the air conditioning unit 20, it is considered that the FC inlet temperature decreases. Although the heater core inlet temperature is higher than that in the case of a closed failure, it is considered that the heater core inlet temperature cannot be normally controlled and decreases.

  As shown in FIG. 5E, when the heater core inlet temperature rapidly rises in the case of an ON failure, the air conditioning ECU 32 estimates that a closed failure has occurred. This is because the amount of heat generated by the electric heater 202 increases with respect to the heat radiation from the heater core 200.

  As shown in F of FIG. 5, in the case of an ON failure, when the FC inlet temperature and the heater core inlet temperature cannot be normally controlled (when at least one of the temperatures continues to be higher than the target temperature), The air conditioning ECU 32 estimates that an open failure has occurred. This is because in the case of an open failure, the heat generated by the electric heater 202 is released from the radiator 110, so that the FC inlet temperature is considered to rise. Although the heater core inlet temperature is lower than that in the case of a closed failure, it is considered that the heater core inlet temperature cannot be normally controlled and rises.

FIG. 6 is a table showing treatments when a failure occurs. Each device is controlled according to the combination of the failure mode of the three-way valve V2 and the failure mode of the electric heater 202. FIG.
The alphabets in parentheses shown in FIG. 5 indicate correspondence with FIG.

  As shown in FIG. 6a, in the case of a closed failure, when the electric heater 202 is normal, special control is not executed. That is, on the premise of the disconnected state, the cooling of the fuel cell stack 100 and the air conditioning of the vehicle interior are executed. In this case, although the effect (improvement of fuel consumption etc.) by using a connection state cannot be enjoyed, a special trouble does not arise.

  As shown in FIG. 6b, in the case of a closed failure and an OFF failure, the air blown into the vehicle cabin can hardly be heated. ). This stop is executed to suppress excessive power consumption.

  As shown in FIG. 6c, in the case of a closed failure and an ON failure, the air conditioning ECU 32 suppresses the temperature rise of the hot water as much as possible. Specifically, the rotational speed of the blower 220 is maximized and the rotational speed of the pump WP2 is set to an optimum value. The higher the number of revolutions of the pump WP2, the more the heat dissipation from the heater core 200 is contributed to, while the amount of heat generated by the pump WP2 is increased to heat the hot water. This measure is executed to protect each device included in the air conditioning unit 20 from high temperatures.

  As shown in d, e, and f of FIG. 6, in the case of an open failure, regardless of the failure mode of the electric heater 202, various temperatures are controlled in the following priority order. The highest priority is the FC inlet temperature, the outlet temperature to the passenger compartment, and finally the passenger compartment temperature. Since an open failure has occurred, these controls are executed on the assumption of a connected state.

  The FC inlet temperature has the highest priority because it is related to the operation of the fuel cell and affects the power generation capacity and the life of the fuel cell stack 100. For example, in the case of an ON failure, if priority is given to the blowout temperature and the passenger compartment temperature, the FC inlet temperature may become too high even if control is performed so that the amount of heat released by the radiator 110 is maximized. In order to avoid this, the air conditioning ECU 32 controls the pump WP2 and the blower 220 to maximize heat dissipation from the heater core 200 and bring the FC inlet temperature close to the target value.

  In the case of an ON failure, it is preferable to lower the blowing temperature using a cooling device regardless of the failure state of the three-way valve V2. The cool air from the cooling device is mixed with the warm air from the heater core 200 before blowing out into the passenger compartment. Such priority-based control is executed, for example, when the cooling inlet load is high and the FC inlet temperature has converged to the target value, while the blowout temperature and the passenger compartment temperature are higher than the target value. It may be confirmed by occurrence of.

  Conversely, in the case of an OFF failure, the FC inlet temperature may be too low. In such a case, the heat medium is heated by the electric heater 202, and the amount of heat released from the heater core 200 is suppressed to raise the FC inlet temperature.

  The reason why the blowing temperature is given priority over the passenger compartment temperature as described above is because the blowing temperature is a parameter that affects the comfort more. For example, in the case of an OFF failure, the amount of heat for air conditioning tends to be insufficient. In this case, for example, the flow rate of the pump WP2 is suppressed, and further, the rotational speed of the blower 220 is suppressed as necessary, thereby suppressing the decrease in the blowing temperature. Note that a change in the operating state of the pump WP2 is easily perceived by the user as a change in noise or vibration in the passenger compartment. From this viewpoint, the operation state of the pump WP2 is preferably as constant as possible. Therefore, in this embodiment, the operation state of the pump WP2 is maintained as constant as possible unless there is a failure.

  As shown in FIGS. 6G and H, in both cases of ON failure and OFF failure, when the three-way valve V2 is normal, the connection state is set by opening the three-way valve V2, The same control as in the case of the open failure described above is executed.

  The reason why the three-way valve V2 is opened in the case of an ON failure is to promote the cooling of the heat medium by utilizing the heat radiation by the radiator 110. In the case of an OFF failure, the three-way valve V2 is opened by supplying the heat medium heated by the fuel cell stack 100 to the air conditioning unit 20, thereby suppressing fluctuations in the blowing temperature and reducing the blowing temperature and the passenger compartment temperature. This is to bring the target value as close as possible.

  According to the above embodiment, the failure mode between the three-way valve V2 and the electric heater 202 can be estimated, and a treatment can be performed based on the estimation result. This measure gives priority to the protection of the fuel cell, and contributes to maintaining a state where self-running is possible.

  The present invention is not limited to the embodiments, examples, and modifications of the present specification, and can be implemented with various configurations without departing from the spirit of the present invention. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in the embodiments described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the effects described above, replacement or combination can be performed as appropriate. If the technical feature is not described as essential in this specification, it can be deleted as appropriate. For example, the following are exemplified.

The specific temperature controlled as the temperature of the fuel cell may be a temperature that reflects the temperature of the cells constituting the fuel cell stack. For example, the temperature measured by a thermometer installed in the fuel cell stack or the temperature of the coolant immediately after flowing out of the fuel cell stack may be used.
In the case of an OFF failure, waste heat from a cooling device (for example, a condenser or a compressor) may be used to heat the heat medium.
At least a part of the control object of the fuel cell ECU may be the control object of the air conditioning ECU 32. Alternatively, at least a part of the control target of the air conditioning ECU may be set as the control target of the fuel cell ECU.
The heat medium may not be water but may be other fluid, for example, silicone oil.
The temperature control system may be mounted on a transport device other than an automobile, for example, a train, a ship, an aircraft, a spacecraft, or the like.
The type of the fuel cell is not limited to the polymer electrolyte fuel cell, but may be, for example, a phosphoric acid fuel cell, a molten carbonate fuel cell, or a solid oxide fuel cell.

DESCRIPTION OF SYMBOLS 1 ... Temperature control system 10 ... Cooling part 20 ... Air conditioning part 24 ... Ventilation duct 31 ... ECU for fuel cells
32 ... ECU for air conditioning
DESCRIPTION OF SYMBOLS 100 ... Fuel cell stack 110 ... Radiator 112 ... Fan 120 ... Cooling flow path 128 ... Bypass 130 ... Temperature sensor 132 ... Temperature sensor 200 ... Heater core 202 ... Electric heater 210 ... Air-conditioning flow path 216 ... 1st connection flow path 218 ... Second connection flow path 220 ... Blower 230 ... Temperature sensor 232 ... Temperature sensor WP1 ... Pump WP2 ... Pump

Claims (8)

A cooling unit for circulating a heat medium to control the temperature of the fuel cell;
An air conditioning unit for circulating a heat medium for air conditioning;
To select either a non-connected state in which a heat medium circulates through each of the cooling unit and the air-conditioning unit or a connected state in which at least a part of the heat medium that circulates through the cooling unit circulates through the air-conditioning unit And the valve
A temperature control device comprising: a control unit that controls the amount of heat released from the heat medium circulating in the air conditioning unit according to the temperature of the fuel cell when the unconnected state cannot be selected by controlling the valve. The temperature control device according to claim 1, wherein the control unit realizes control of the heat radiation by controlling a flow rate of a heat medium in the air conditioning unit. The control unit estimates that a failure has occurred in the valve when a change in the temperature of the heat medium measured in the air-conditioning unit is smaller than a predetermined value when performing control to change the degree of opening and closing of the valve. The temperature control device according to claim 1 or 2. The temperature control device according to claim 3, wherein the control unit estimates a failure mode of the valve based on a state of temperature control of the heat medium. The air conditioning unit includes a heater that heats the heat medium,
The said control part is set to the said connection state by controlling the said valve, when it detects that the said heater cannot exhibit predetermined | prescribed heat generation capability, It is any one of Claim 1- Claim 4 set. Temperature control device. The temperature control device according to claim 5, wherein the control unit performs the detection based on a fact that power consumption by the heater is small with respect to a duty of the heater. When the temperature of the fuel cell does not decrease to a target value depending on the control of the cooling unit, the control unit controls the amount of heat released according to the temperature of the fuel cell and is larger than the amount of heat released for the air conditioning. The temperature control device according to any one of claims 1 to 6, wherein the air conditioning unit is caused to perform heat radiation of an amount. The temperature of the heat medium circulating in the cooling section to control the temperature of the fuel cell;
A method for controlling the temperature of a heat medium circulating in an air conditioning unit for air conditioning,
When at least part of the heat medium circulating through the cooling unit cannot be switched from a connected state in which the heat medium circulates through the air conditioning unit to a non-connected state in which the heat medium circulates through each of the cooling unit and the air conditioning unit, A temperature control method for controlling an amount of heat released from the air conditioning unit according to a temperature of the fuel cell.

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