Air conditioning for vehicle

Abstract

Air conditioning system for a vehicle, designed to blow conditioned air into the interior of the vehicle, the air conditioning system comprising: a first circuit (18) in which a cooling medium circulates to cool a drive source (11) of the vehicle; a heater (17) that heats the cooling medium circulating in the first circuit, consuming power in a storage device (13) installed in the vehicle; a heating heat exchanger (19) which is arranged in the first circuit and heats the air conditioning air passing through the heating heat exchanger by exchanging heat with the air conditioning air passing through the heating heat exchanger using the cooling medium; a first pump (20) which is arranged in the first circuit and forces the cooling medium to circulate in the first circuit; a second circuit (23) that cools a heat-emitting section (12) installed on the vehicle, allowing the cooling medium circulating in the first circuit to circulate in the second circuit; a second pump (27) which is arranged in the second circuit and forces the cooling medium to circulate in the second circuit; a control section (21) that connects the first circuit and the second circuit and controls a circulation quantity of the cooling medium flowing in the first circuit and a circulation quantity of the medium flowing in the second circuit; and a control section (16) that controls the heating, the adjustment section, the first pump and the second pump, characterized by the fact that the vehicle includes a recovery device (14) which recovers energy by converting kinetic energy into electrical energy during the deceleration of the vehicle, that the storage device is charged with the electrical energy recovered by the recovery device, that when the recovery device recovers electrical energy in a state requiring consumption, in which it is determined that power must be consumed in the storage device by the air conditioner, the control section controls the heater, the adjustment section, the first pump and the second pump to heat the cooling medium by driving the heater, so that the power in the storage device is converted into heat energy, and that the air conditioning system further includes: a first temperature sensor (22) that detects the temperature of the cooling medium circulating in the first circuit; and a second temperature sensor (28) that detects the temperature of the cooling medium circulating in the second circuit, wherein: If, in the state requiring consumption, a temperature detected by the second temperature sensor is lower than a predetermined temperature, the control section heats the cooling medium by driving the heater and controls the adjustment section, the first pump and the second pump to force the cooling medium circulating in the first circuit to also circulate in the second circuit; and If, in the state requiring consumption, the temperature detected by the second temperature sensor is greater than or equal to the set temperature, the control section heats the cooling medium by driving the heater and controls the adjustment section and the first pump to force the cooling medium to circulate in the first circuit, while preventing the cooling medium from circulating from the first circuit to the second circuit.

Description

Technical area

[0001] The present disclosure relates to an air conditioning system for a vehicle according to the preamble of claim 1, which air-conditions using energy recovered by a regenerative brake. Background technology

[0002] In recent years, a societal demand for fuel-efficient vehicles has spread the use of regenerative braking, which generates power by driving a motor using kinetic energy during a vehicle's deceleration—that is, wheel rotation—and stores it in a battery. Regenerative braking recovers energy by converting kinetic energy during the vehicle's deceleration into power that is stored in the battery.

[0003] In a case where power is regenerated by the regenerative braking system and stored in the battery as described above, the regenerative power generation amount can be increased beyond the allowable power of the battery. Therefore, to prevent excessive power supply to the battery, a vehicle control device described in JP 2010-268639 A consumes power by carefully driving an electric compressor provided for air conditioning and other high-voltage auxiliary devices.

[0004] US 5 291 960 A discloses a regenerative braking energy recovery system that converts the engine of a motor vehicle into a generator for outputting useful electrical energy.

[0005] JP 2011- 098 670 A and JP 2012- 195 263 A disclose a generic air conditioning system for a vehicle. Summary of the invention

[0006] In the case of the control device as above, when the battery is charged by the regenerative brake for a considerable time, such as during a long downhill journey, an increase in battery charging power cannot be prevented even by driving the high-voltage auxiliary devices. In such a case, the regenerative brake must be turned off and switched to a hydraulic brake, resulting in brake wear and deterioration of the driving feel during switching of the braking systems.

[0007] An object of the present disclosure is to further develop an air conditioning system for a vehicle according to the preamble of claim 1 such that energy recovered by a regenerative brake is not only capable of being charged into a battery but is also capable of being used for air conditioning in a vehicle interior.

[0008] The object is achieved according to the invention by an air conditioning system having the features of independent patent claim 1. Advantageous further developments are defined in the dependent patent claims.

[0009] The air conditioner includes the heater, which heats the cooling medium circulating in the first circuit by consuming power from the storage device installed in the vehicle. When the recovery device recovers electrical energy and the air conditioner needs to consume power from the power storage device, the control section heats the cooling medium by driving the heater and controls the heater, the adjustment section, the first pump, and the second pump to convert power from the storage device into heat energy.

[0010] According to the configuration as above, the air conditioner performs special control when the recovery device recovers electric energy in a consumption-required state in which it is determined that the air conditioner needs to consume power in the storage device. Electric energy recovered by the recovery device is consumed by a power-consuming device of the vehicle and also charged into the storage device. However, when the power consumption by the power-consuming device is small and when the storage device has a power storage limit, electric energy recovered by the recovery device may not be consumed and may be wasted. To prevent such waste, the air conditioner performs special control to convert the recovered electric energy into heat energy.

[0011] Specifically, the control section heats the cooling medium by driving the heater, and controls the heater, the adjusting section, the first pump, and the second pump to convert power in the storage device into heat energy. When the heater is driven, electrical energy is consumed and is thereby converted into heat energy. Also, by controlling the first pump, the second pump, and the adjusting section, circulation amounts of the cooling medium circulating in the first circuit and the second circuit can be controlled. Consequently, the heater can be driven according to a temperature of the cooling medium and a heating value necessary for air conditioning. Consequently, energy recovered by the recovery device can be charged into the storage device and also used to condition air in the vehicle interior.As a result, the probability that the recovery device will be turned off can be reduced. Consequently, energy recovered by the recovery device can be used efficiently. Short description of the drawings Fig. 1 is a block diagram showing an electrical configuration of a system including an air conditioner for a vehicle according to an embodiment. Fig. 2 is a view showing an air conditioning hot water circuit of the air conditioner; Fig. 3 is a view showing a state in which the air conditioning hot water circuit and a cooling circuit are connected to each other; Fig. 4 is a flowchart showing control of a heater by a power management ESG; and Fig. 5 is a flowchart showing control of a three-way valve by an air conditioning ECU. Description of embodiments

[0012] One embodiment is described using Fig. 1 to Fig. 5. An air conditioning system 10 for a vehicle blows conditioning air to condition air in the vehicle. As shown in Fig. As shown in Figure 1, the air conditioner 10 is installed in a fuel cell hybrid vehicle (FCHV) having a traction motor 11 as a traction drive source and fuel cells (FC stack) 12 as a power supply section for the traction motor 11. Consequently, the traction motor 11 is driven with a power supply from both the FC stack 12 and a battery 13 in the vehicle.

[0013] A regenerative brake 14, as a regenerative device, is electrically connected to the battery 13. The regenerative brake 14 recovers energy by converting kinetic energy during vehicle deceleration. The regenerative brake 14 charges the recovered electrical energy into the battery 13, which is a storage device.

[0014] The fuel cell stack 12 contains multiple fuel cells, each generating power through an electrochemical reaction between hydrogen and oxygen. The fuel cell stack 12 can be made of solid polymer fuel cells. However, it should be appreciated that the fuel cell stack is not limited to solid polymer fuel cells; phosphoric acid fuel cells, molten carbonate fuel cells, and similar fuel cells are also available.

[0015] As in Fig. As shown in Figure 1, a power management ECU 15 (hereinafter occasionally abbreviated as P / M ECU 15) controls the traction motor 11. The P / M ECU 15 also exchanges necessary information with the FC stack 12 and an air conditioning ECU 16 of the air conditioner 10 via CAN (Controller Area Network (registered trademark)) communication. The P / M ECU 15 determines an amount of power to be supplied to the traction motor 11 based on an amount of power generation in the FC stack 12, a remaining amount of the battery 13, a traveling state of the vehicle, and so on. The P / M ECU 15 controls the traction motor 11 to be driven with the determined amount of power.

[0016] The air conditioning system 10 has, as in Fig. 2, a system configured with a high-voltage water heater (hereinafter referred to simply as the heater) 17 that heats water in an air-conditioning hot water circuit 18 to release heat at a heater core 19. The air-conditioning hot water circuit 18 is a first circuit in which water is circulated to cool the traction motor 11 as a power source of the vehicle.

[0017] The air conditioning hot water circuit 18 forms a circulation channel for hot water (water) as a cooling medium to be circulated. The air conditioning hot water circuit 18 includes an air conditioning electric pump 20 that forces water to circulate in the air conditioning hot water circuit 18, the heater 17 that heats water, a first temperature sensor 22 that detects a temperature of circulating hot water, and the heater core 19. Thus, the heater 17 is used as a heat source when providing air conditioning air by heating air to be blown into the vehicle interior. The heater core 19 is configured such that the hot water heated by the heater 17 flows through the heater core 19.

[0018] The first temperature sensor 22 detects a temperature of water circulating in the air conditioning hot water circuit 18. The first temperature sensor 22 detects a temperature of hot water after flowing out of the heater 17 and before flowing into the heater core 19. The first temperature sensor 22 provides detected temperature information to the air conditioning ECU 16. The first temperature sensor 22 can be implemented, for example, by an in-line thermistor.

[0019] DC power received from the vehicle's battery 13 is supplied to the heater 17, while the operating time is separately controlled, for example, by an inverter section. While the power is supplied, the heater 17 consumes a constant amount of power. The heater 17 can be implemented, for example, by a sheathed heater using a nichrome wire.

[0020] The heater core 19 is a heater heating section (heating heat exchanger) that heats the air conditioning air flowing inside an air conditioning case using cooling water as a heating source. The heater core 19 is arranged in the air conditioning case on a downstream side in a flow of the air conditioning air. A cooling water passage is provided inside the heater core 19. Thus, when the cooling water flows in the cooling water passage, the heater core 19 heats the air conditioning air passing through the heater core 19 itself by releasing heat from the cooling water into the air conditioning air.

[0021] A cooling circuit 23, which cools the FC stack 12, is connected to the air conditioning hot water circuit 18. Specifically, the cooling circuit 23 is connected to the air conditioning hot water circuit 18 via two connecting passages to allow water circulating in the air conditioning hot water circuit 18 to also circulate in the cooling circuit 23. A three-way valve 21 is provided at one of the connecting passages.

[0022] By opening and closing, the three-way valve 21 connects the cooling circuit 23 and the air conditioning hot water circuit 18, as shown in Fig. 3 (interaction) and separates the cooling circuit 23 from the air conditioning hot water circuit 18, as shown in Fig. 2 (they operate independently). In other words, the three-way valve 21 switches a channel of the cooling water circulating in the air conditioning hot water circuit 18 according to a displacement of a valve body to a position shown in Fig. 2, in which the cooling water circulates only in the air conditioning hot water circuit 18, or a state shown in Fig. 3, in which the cooling water also circulates in the cooling circuit 23. The three-way valve 21 can be implemented, for example, by a servomotor 21b using a potentiometer. The servomotor 21b causes the three-way valve 21 to change a position of the valve body. A potentiometer 21a detects a position of the valve body. The servomotor 21b is driven to position the valve body in a predetermined position based on the position of the valve body detected by the potentiometer 21a. Consequently, the three-way valve 21 functions as an adjusting portion that regulates a circulation amount of water flowing in the air-conditioning hot water circuit 18 and a circulation amount of water flowing in the cooling circuit 23.

[0023] The air conditioning pump 20 is a first pump and is arranged in the air conditioning hot water circuit 18 at a position downstream of the three-way valve 21 and upstream of the heater 17. The air conditioning pump 20 is a circulation pump that forces the cooling water to circulate in the air conditioning hot water circuit 18. The air conditioning pump 20 may, for example, be a pump device configured to drive an impeller inside a pump housing.

[0024] The air conditioning (A / C) ECU 16 is a control section including a microcomputer and peripheral circuits. The A / C ECU 16 performs calculation processing according to a preset program using various temperature signals from the first temperature sensor 22, an outside air temperature sensor, and an inside air temperature sensor, as well as a solar radiation signal from a solar radiation sensor, a preset temperature signal set by an occupant via an unillustrated operation panel, and so on. Likewise, the A / C ECU 16 controls the three-way valve 21, the air conditioning pump 20, an air blower (not shown), an air mix door (not shown), and so on according to a calculation result. Furthermore, the A / C ECU 16 controls operation of the heater 17 via the P / M ECU 15 in response to a heating request by communicating with the P / M ECU 15 via CAN communication.

[0025] The cooling circuit 23 will now be described. The fuel cell hybrid vehicle has, as shown in Fig. 2, the cooling circuit 23 cools the FC stack 12. The cooling circuit 23 is a circuit that forces the cooling water (corresponding to the cooling medium) to circulate outside the FC stack 12 by flowing out of the FC stack 12 and returning to the FC stack 12. The cooling circuit 23 connects a cooling water outlet and a cooling water inlet of the FC stack 12. The cooling circuit 23 and the air conditioning hot water circuit 18 are connected via the connecting passages 24 to allow the water circulating in the air conditioning hot water circuit 18 to also circulate in the cooling circuit 23. The cooling circuit 23 is provided with a radiator 25, a rotary valve 26, and a fuel cell pump 27. A second temperature sensor 28, which detects a temperature of the cooling water in the cooling circuit 23, is provided inside the fuel cell stack 12.

[0026] The fuel cell stack 12 supplies power necessary for the vehicle to run. A heating value generated by the fuel cell stack 12 during power generation is substantially as high as a heating value generated by an internal combustion engine. Therefore, even a passenger vehicle is equipped with the radiator 25, which is as large as a radiator used for a truck as a radiant heat exchanger. The radiator 25 is arranged in the cooling circuit 23 and releases heat of the cooling water to the outside by exchanging heat with outside air. Thus, the radiator 25 is a radiant heat exchanger that cools the cooling water that becomes hot in the fuel cell stack 12. The radiator 25 is arranged, for example, inside an engine compartment, for example, in a front part behind a grill. The radiator 25 is provided with a blower fan (not shown). The radiator 25 cools the cooling water with cooling air supplied by the blower fan.

[0027] The cooling circuit 23 has a bypass passage 29 for allowing the cooling water to flow bypassing the radiator 25. Namely, the bypass passage 29 is provided such that it branches from the cooling circuit 23 at a branching point upstream of the radiator 25 in a flow of the cooling water and joins the cooling circuit 23 at a merging point downstream of the radiator 25 in the flow of the cooling water.

[0028] The rotary valve 26 is a valve device provided at the branching point where the bypass passage 29 branches from the cooling circuit 23 to regulate a flow ratio between the cooling water passing through the radiator 25 and the cooling water passing through the bypass passage 29. The rotary valve 26 uses an internal valve and switches opening and closing states between a case where water is allowed to flow through the radiator 25 by opening one side of the radiator 25 and closing one side of the bypass passage 29, and a case where water is allowed to flow through the bypass passage 29 by opening the side of the bypass passage 29 and closing the side of the radiator 25.

[0029] The fuel cell pump 27 is a second pump and is arranged in the cooling circuit 23 at a position downstream of the junction point where the bypass passage 29 joins the cooling water flow with the cooling circuit 23. Namely, the fuel cell pump 27 is located downstream of the junction point of the bypass passage 29 with the cooling circuit 23 and upstream of the FC stack 12. The fuel cell pump 27 is a circulation pump that forces the cooling water to circulate in the cooling circuit 23. The fuel cell pump 27 may, for example, be a pump device configured to rotate an impeller inside a pump housing.

[0030] The FC stack 12 includes a fuel cell ECU (not shown). The fuel cell ECU is a control section that controls the FC stack 12. The fuel cell ECU receives information inputs about a calorific value of the fuel cells output from the FC stack 12 or a physical quantity (e.g., a power generation amount) related to the calorific value, and temperature information output from the second temperature sensor 28. The fuel cell ECU controls operations of the rotary valve 26 and the fuel cell pump 27 according to the input information, as specified above.

[0031] A control on the heater 17 is now carried out using Fig. 4. In actual operations, the air conditioning ESG 16 controls the heater 17 indirectly via the P / M ESG 15. The P / M ESG 15 repeatedly performs a Fig. 4 when an ignition of the vehicle is ON.

[0032] In step S41, it is determined whether power is being regenerated from the regenerative brake 14. If power is being regenerated, the process proceeds to step S47. If no power is being regenerated, the process proceeds to step S42.

[0033] Since no power is regenerated, in step S42, an air-conditioning water temperature TW is obtained from the first temperature sensor 22, and advancement to step S43 is performed. In step S43, a target water temperature TWO of the air-conditioning hot water circuit 18 is calculated based on a vehicle heat load and a preset interior temperature obtained from various sensors, and advancement to step S44 is performed. The vehicle heat load is calculated using an outside air temperature, an inside air temperature, an amount of solar radiation, and a preset interior temperature, and so on.

[0034] In step S44, the target water temperature TWO and the air-conditioning water temperature TW are compared. If the target water temperature TWO is greater than or equal to the air-conditioning water temperature TW, the process proceeds to step S45. If the target water temperature TWO is lower than the air-conditioning water temperature TW, the process proceeds to step S46.

[0035] Since the target water temperature TWO is higher than the air-conditioning water temperature TW in step S45, water in the air-conditioning hot water circuit 18 requires heating. Consequently, the heater 17 is driven (turned on) under control, and the flow is stopped.

[0036] Since the target water temperature TWO is below the air-conditioning water temperature TW in step S46, water in the air-conditioning hot water circuit 18 does not require heating. Consequently, the heater 17 is controlled to stop (turn off) under control, and the flow is terminated.

[0037] Since power is regenerated by the regenerative brake 47, in step S47 under control, the heater 17 is driven (turned on) to consume power and the flow is stopped.

[0038] As described, in the normal heating in which no power is regenerated by the regenerative brake 14, as described in step S42 to step S46, the target water temperature TWO is calculated based on the vehicle heat load (step S43), and the heater 17 is driven to be turned ON or OFF according to a difference between the target water temperature TWO and the air-conditioning water temperature TW. The heater 17 has at least two drive levels (W) including an OFF level, and the drive levels are realized by PID control. Likewise, the heater 17 is driven with a high voltage at the FC stack 12 or the battery 13, and a calorific value of the generated heat is released to the heater core 19 via a fluid in the air-conditioning hot water circuit 18. Consequently, the vehicle interior can be heated to a desired temperature.

[0039] When power is regenerated, by turning on the heater 17 using power generated by the regenerative brake 14, braking energy can be stored in the form of heat in the air conditioning hot water circuit 18. Consequently, in the case of heating during the winter months, the drive frequencies of the heater 17 by the FC stack 12 can be reduced. Consequently, an energy-saving effect can be achieved.

[0040] A control of the three-way valve 21 is now carried out using Fig. 5. The air conditioning ESG 16 repeatedly performs a Fig. 5 when the vehicle ignition is ON.

[0041] In step S51, it is determined whether power is being regenerated from the regenerative brake 14. If power is being regenerated, the process proceeds to step S57. If no power is being regenerated, the process proceeds to step S52.

[0042] In step S52, it is determined whether the air mix door is fully opened to a maximum cooling position. If the air mix door is fully opened to the maximum cooling position (MAX COOL), advancement is performed to step S56. If the air mix door is not fully opened to the maximum cooling position, advancement is performed to step S53. The air mix door is a rotary door for regulating a volume of air conditioning air passing near the heater core 19. A flow ratio of heating air passing through the heater core 19 to cooling air bypassing the heater core 19 is regulated according to an opening degree of the air mix door. Consequently, a temperature of the air conditioning air downstream of the heater core 19 is regulated. Thus, the maximum cooling position is an opening position of the air mix door in which the cooling capacity is fully exerted.In other words, when the air mix damper is in the maximum cooling position, air does not need heating by the heater core 19.

[0043] Since the air mix door is not in the maximum cooling position in step S53, it is determined whether the air conditioning water temperature TW is greater than or equal to a predetermined temperature. If the air conditioning water temperature TW is greater than or equal to the predetermined temperature, the process proceeds to step S54. If the air conditioning water temperature TW is lower than the predetermined temperature, the process proceeds to step S56.

[0044] In step S54, it is determined whether a temperature of the FC stack 12 is greater than or equal to a predetermined temperature. If the temperature of the FC stack 12 is greater than or equal to the predetermined temperature, the process proceeds to step S55. If the temperature of the FC stack 12 is lower than the predetermined temperature, the process proceeds to step S56.

[0045] Since the air mix damper is not in the maximum cooling position, the air needs heating in step S55. Also, the air conditioning water temperature is greater than or equal to the preset temperature due to heating by the heater 17, and the temperature of the fuel cell stack 12 is greater than or equal to the preset temperature. Consequently, the three-way valve 21, as shown in Fig. 3, so that the cooling circuit 23 and the air conditioning hot water circuit 18 operate cooperatively. Consequently, the heating capacity is ensured using a calorific value in the FC stack 12.

[0046] Advance to step S56 is performed when the air mix damper is in the maximum cooling position, when the air conditioning water temperature TW is below the predetermined temperature, or when the temperature of the FC stack 12 is below the predetermined temperature. Consequently, in step S56, the three-way valve 21 is controlled to operate the air conditioning hot water circuit 18 independently, thereby allowing water to circulate in the air conditioning hot water circuit 18 while preventing water from flowing in from the cooling circuit (a Fig. 2). The flow is then stopped.

[0047] If power is not recovered as above, a heating value in the FC stack 12 is effectively used. Consequently, if the heating power by the heater 17 alone is not sufficient, the three-way valve 21 is opened to heat the air conditioning hot water circuit 18 and the cooling circuit 23, as shown in Fig. 3. Consequently, a heating value generated in the FC stack 12 can be provided to the air conditioning hot water circuit 18. When a heating value is insufficient, the three-way valve 21 is closed to allow the air conditioning hot water circuit 18 to operate as a mechanism independent of the cooling circuit 23.

[0048] The processing when power is recovered is now also done using Fig. 5. Since power is being regenerated, it is determined in step S57 whether the temperature of the FC stack 12 is greater than or equal to a predetermined temperature. If the temperature of the FC stack 12 is greater than or equal to the predetermined temperature, the process proceeds to step S58. If the temperature of the FC stack 12 is lower than the predetermined temperature, the process proceeds to step S510.

[0049] In step S58, it is determined whether the air-conditioning water temperature TW is greater than or equal to a predetermined temperature. If the air-conditioning water temperature TW is greater than or equal to the predetermined temperature, the process proceeds to step S510. If the air-conditioning water temperature TW is lower than the predetermined temperature, the process proceeds to step S59.

[0050] Since the temperature of the FC stack 12 is greater than or equal to the predetermined temperature and the air conditioning water temperature TW is lower than the predetermined temperature, the three-way valve 21 is controlled in step S59 to make the air conditioning hot water circuit 18 operate independently. Then, the flow is stopped. When power is recovered, the FC stack 12 suspends power generation. However, in a case where the temperature of the FC stack 12 decreases under such circumstances, sufficient power generation and drive power cannot be ensured when the FC stack 12 resumes operation. To avoid such a problem, when the air conditioning water temperature TW is below the predetermined temperature, the air conditioning hot water circuit 18 is controlled to operate independently to prevent the temperature of the FC stack 12 from decreasing.

[0051] Since the temperature of the FC stack 12 is lower than the predetermined temperature or since the air conditioning water temperature TW is greater than or equal to the predetermined temperature, the three-way valve 21 is controlled in step S510 as shown in Fig. 3, so that the air conditioning hot water circuit 18 and the cooling circuit 23 operate cooperatively. Consequently, the heating capacity is ensured using a calorific value in the fuel cell stack 12.

[0052] The FC stack 12 must be maintained at an optimal temperature to achieve maximum power generation efficiency. When power is regenerated, the FC stack 12 does not generate power because no drive power is required and the stack temperature is low. However, when power regeneration ends, for example, at the end of a downstream run, drive power becomes necessary. If the temperature of the FC stack 12 is low at this time, sufficient power generation cannot be ensured. To avoid such a difficulty, when the temperature of the FC stack 12 is low, a calorific value in the heater 17 driven by the power generated by the regenerative brake 14 is used by fixing the three-way valve 21 in a position to allow the air conditioning hot water circuit 18 and the refrigeration circuit 23 to operate cooperatively (step S510).Consequently, heat can also be stored in the cooling circuit 23, and a sufficiently high power generation capability can be ensured before a need for drive power arises at the end of a downlink.

[0053] When the temperature of the FC stack 12 is sufficiently high, the three-way valve 21 is fixed in a position to force the air conditioning hot water circuit 18 to operate independently (step S59). Consequently, heating can be performed by allowing the heater core 19 to utilize a calorific value in the heater 17 driven by power generated by the regenerative brake 14. Consequently, it is no longer necessary to generate power in the FC stack 12 and supply power to the heater 17. Thus, an energy-saving effect can be achieved.

[0054] If an independent operation mode continues during recovery, the temperature of the air-conditioning water rises. In this case, resin components constituting the air conditioner 10 surrounding the air-conditioning hot water circuit 18 may be exposed to high temperatures and experience deformation. For example, in a case where the air-conditioning water temperature TW rises to 85°C or higher, it is preferable to store heat in all the circuits including the cooling circuit 23 by allowing the air-conditioning hot water circuit 18 and the cooling circuit 23 to operate cooperatively, even if the temperature of the FC stack 12 is high. As power recovery continues, the temperature of the FC stack 12 also rises, and it is preferable to finally release heat to the radiator 25 by opening the rotary valve 26.Consequently, the regenerative brake 14 is allowed to operate continuously over a long period of time.

[0055] As described hereinabove, the air conditioner 10 of the present embodiment performs special control when the regenerative brake 14 regenerates electric energy in a consumption-necessary state in which it is determined that the air conditioner 10 needs to consume power in the battery 13. Energy regenerated by the regenerative brake 14 is consumed in the form of power from a power-consuming device of the vehicle and also charged into the battery 13. However, when the power consumption by the power-consuming device is small and when the battery 13 has a power storage limit, the electric energy regenerated by the regenerative brake 14 may not be consumed and may be wasted. To prevent such waste, the air conditioner 10 performs special control to convert the regenerated electric energy into heat energy.

[0056] Specifically, the control section heats water by driving the heater 17 and controls the heater 17, the three-way valve 21, the air conditioning pump 20, and the fuel cell pump 27 to convert power in the battery 13 into heat energy. When the heater 17 is driven, electrical energy is consumed and thereby converted into heat energy. Also, by controlling the air conditioning pump 20, the fuel cell pump 27, and the three-way valve 21, circulation amounts of water circulating in the air conditioning hot water circuit 18 and the cooling circuit 23 can be controlled. Consequently, the heater 17 can be driven according to a water temperature and a heating value necessary for air conditioning. Consequently, energy recovered by the regenerative brake 14 can be charged to the battery 13 and also used to condition the air in the vehicle interior.Consequently, the probability of the regenerative brake 14 being turned off can be reduced. Consequently, energy recovered by the regenerative brake 14 can be used efficiently.

[0057] In other words, the air conditioning system 10 in the present embodiment includes the three-way valve 21 that allows the cooling circuit 23 to communicate with the air conditioning hot water circuit 18, in which the heater 17 is connected to the heater core 19. When regeneration is requested, the heater 17 is driven. Further, the three-way valve 21 is driven to a position to allow the air conditioning hot water circuit 18 to communicate with the cooling circuit 23. Consequently, the regenerative brake 14 can be used for a long period of time on a downstream route by using a cooperative structure of the cooling circuit 23 of the FC stack 12 in the FCHV and the air conditioning hot water circuit 18. Likewise, the power generated by the regenerative brake 14 in the electric motor can be effectively used in a section where power is necessary.

[0058] In the present embodiment, when the condition where power consumption is necessary exists, the air conditioning ECU 16 heats water by driving the heater 17 and controls the three-way valve 21, the air conditioning pump 20, and the fuel cell pump 27 to allow water circulating in the air conditioning hot water circuit 18 to also circulate in the cooling circuit 23. Consequently, the heat generated at the heater 17 can be used as heat to be stored in the air conditioning hot water circuit 18 and the cooling circuit 23.

[0059] In the present embodiment, when the condition where power consumption is required exists while the temperature of the FC stack 12 is below the predetermined temperature, the air conditioning ECU 16 heats water by driving the heater 17 and controls the air conditioning hot water circuit 18 and the cooling circuit 23 to operate cooperatively. Consequently, the temperature of the FC stack 12 after recovery can be adjusted to be close to the predetermined temperature. Therefore, when the FC stack 12 is restarted, sufficient power generation and driving power can be ensured.

[0060] When the condition where power consumption is required exists while the temperature of the FC stack 12 is greater than or equal to the predetermined temperature, the air conditioning ECU 16 heats water by driving the heater 17 and performs control to allow water to circulate independently in the air conditioning hot water circuit 18 and the cooling circuit 23. Consequently, the temperature of the FC stack 12 can be prevented from decreasing.

[0061] In the present embodiment, when the condition where power consumption is required exists while the air-conditioning water temperature TW is equal to or greater than a first predetermined temperature and the temperature of the FC stack 12 is below a second predetermined temperature, the air-conditioning ECU 16 heats a cooling medium by driving the heater 17. Further, the air-conditioning ECU 16 performs control for the air-conditioning hot water circuit 18 and the cooling circuit 23 to operate cooperatively. Consequently, the temperature of the FC stack 12 after regeneration can be adjusted to be close to the second predetermined temperature while restraining an excessive increase in the air-conditioning water temperature TW.Consequently, sufficient power generation and drive power can be ensured when the FC stack 12 is restarted while limiting an excessive increase in the air conditioning water temperature TW.

[0062] In the present embodiment, when the condition where power consumption is required exists while the air-conditioning water temperature TW is greater than or equal to the first predetermined temperature and while the temperature of the FC stack 12 is greater than or equal to the second predetermined temperature, the air-conditioning ECU 16 controls the radiator 25 to release heat. Specifically, a flow rate of the cooling medium passing through the radiator 25 is controlled by the three-way valve 21 and the rotary valve 26 to lower a temperature of the cooling circuit 23 below the second predetermined temperature. When both the air-conditioning water temperature TW and the temperature of the FC stack 12 are high, heat can be released from the radiator 25 while the air-conditioning hot water circuit 18 and the cooling circuit 23 operate cooperatively.Consequently, an excessive increase in the temperature of both the air conditioning water temperature TW and the temperature of the fuel cell stack 12 can be limited. Furthermore, because the regenerative brake 14 can be continuously operated, the application of the hydraulic brake can be limited. Consequently, wear-induced damage to the hydraulic brake can be limited.

[0063] The present disclosure is not limited to the embodiments described above and may have various modifications as described below without departing from the spirit of the present disclosure.

[0064] The scope of the present disclosure is not limited to the scope exemplified by the structure of the embodiment. The scope of the present disclosure is shown by the appended claims and also includes all equivalent modifications.

[0065] In the above embodiment, the heater 17 uses an air conditioning heater. However, a heater 17 provided for exclusive use of the fuel cell stack 12 may be driven. Likewise, a 12V low-voltage water heater may be used as the heater 17 to reduce the voltage to 12V using a DC-DC converter.

[0066] In the above embodiment, recovered electrical energy is stored in the form of heat energy in the refrigeration circuit 23. However, the present disclosure is not limited to the structure for storing heat energy in the refrigeration circuit 23. For example, the FC stack 12 may be replaced with a large-capacity hot water thermal storage tank from the viewpoint of storing heat and maintaining recovery.

[0067] In the above embodiment, the FC stack 12 is the heat-emitting portion cooled by the cooling circuit 23 as a second circuit. However, the heat-emitting portion is not limited to the FC stack 12. For example, the cooling circuit 23 may cool another heat-emitting portion, such as an internal combustion engine of a hybrid vehicle.

[0068] In the above embodiment, only one heater is provided. However, the heater is not limited to one heater. Multiple heaters may be provided on the air-conditioning hot water circuit 18, or another heater may be provided in addition to the cooling circuit 23.

Claims

[1] An air conditioning system for a vehicle, which is designed to blow conditioning air into an interior of the vehicle, the air conditioning system comprising: a first circuit (18) in which a cooling medium circulates to cool a power source (11) of the vehicle; a heater (17) which heats the cooling medium circulating in the first circuit, consuming power in a storage device (13) installed in the vehicle; a heating heat exchanger (19) arranged in the first circuit and heating the air conditioning air passing through the heating heat exchanger using the cooling medium by exchanging heat with the air conditioning air passing through the heating heat exchanger; a first pump (20) arranged in the first circuit and forcing the cooling medium to circulate in the first circuit; a second circuit (23) which cools a heat-emitting portion (12) installed on the vehicle, wherein the cooling medium circulating in the first circuit is allowed to circulate in the second circuit; a second pump (27) arranged in the second circuit and forcing the cooling medium to circulate in the second circuit; an adjusting section (21) connecting the first circuit and the second circuit and controlling a circulation amount of the cooling medium flowing in the first circuit and a circulation amount of the medium flowing in the second circuit; and a control section (16) which controls the heater, the setting section, the first pump and the second pump, characterized by , that the vehicle comprises a recovery device (14) which recovers energy by converting kinetic energy into electrical energy during deceleration of the vehicle, that the storage device is charged with the electrical energy recovered by the recovery device, that when the recovery device recovers the electrical energy in a state requiring consumption in which it is determined that power in the storage device must be consumed by the air conditioner, the control section controls the heater, the adjustment section, the first pump and the second pump to heat the cooling medium by driving the heater, so that the power in the storage device is converted into heat energy, and that the air conditioning system further comprises: a first temperature sensor (22) which detects a temperature of the cooling medium circulating in the first circuit; and a second temperature sensor (28) which detects a temperature of the cooling medium circulating in the second circuit, wherein: when, in the condition requiring consumption, a temperature detected by the second temperature sensor is lower than a predetermined temperature, the control section heats the cooling medium by driving the heater and controls the adjusting section, the first pump, and the second pump to force the cooling medium circulating in the first circuit to also circulate in the second circuit; and when, in the consumption-requiring state, the temperature detected by the second temperature sensor is equal to or greater than the predetermined temperature, the control section heats the cooling medium by driving the heater and controls the adjusting section and the first pump to force the cooling medium to circulate in the first circuit while preventing the cooling medium from circulating from the first circuit to the second circuit. [2] An air conditioning system according to claim 1, wherein: when, in the consumption-requiring state, a temperature detected by the first temperature sensor is equal to or greater than a first predetermined temperature and when the temperature detected by the second temperature sensor is lower than a second predetermined temperature, the control section heats the cooling medium by driving the heater and controls the adjusting section, the first pump, and the second pump to force the cooling medium circulating in the first circuit to also circulate in the second circuit. [3] An air conditioning system according to claim 1, further comprising: a radiant heat exchanger (25) arranged in the second circuit for releasing a quantity of heat of the cooling medium passing through the radiant heat exchanger to outside air, wherein: the adjusting section controls a flow rate of the cooling medium flowing to the radiant heat exchanger; and when, in the consumption-requiring state, a temperature detected by the first temperature sensor is greater than or equal to a first predetermined temperature and when the temperature detected by the second temperature sensor is greater than or equal to a second predetermined temperature, the control section controls the adjustment section to adjust a flow rate of the cooling medium passing through the radiation heat exchanger so that the temperature of the second circuit becomes lower than the second predetermined temperature. [4] An air conditioning system according to any one of claims 1 to 3, wherein: the heat-emitting portion cooled by the second circuit is a fuel cell (12).

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