Fuel cell automobile heat recovery cooling system

Abstract

The invention discloses a heat recovery cooling system of a fuel cell automobile. The heat recovery cooling system comprises a fuel cell cooling unit, a driving motor cooling unit and a high-energy heat recovery cooling unit, the fuel cell cooling unit comprises a fuel cell stack, a deionizer, a stack cooling water pump, a first port of a coupling heat exchange device, a thermostat, a heater PTC (Positive Temperature Coefficient), a first port of a stack preheater and an expansion water tank; the driving motor cooling unit comprises a pile preheater second port, a motor radiator first port and a motor cooling pump; the high-energy heat recovery cooling unit comprises a coupling heat exchange device second port, a motor radiator second port, a turbine, a hydrogen heat exchanger, an intercooler, a booster pump and a condenser; the problem that an existing fuel cell automobile heat recovery cooling system cannot efficiently utilize waste heat of a fuel cell is solved.

Description

Technical Field

[0001] The present invention belongs to the field of fuel cell cooling systems, and in particular, relates to a heat recovery cooling system for a fuel cell vehicle. Background Art

[0002] In the fuel cell vehicle system, the motor and motor controller have high power and generate heat during operation. A cooling system is required to discharge the waste heat to the outside world. This process not only discharges heat but also consumes electricity. In addition, during the operation of the fuel cell system, a cooling system is required to discharge the waste heat generated by the fuel cell system to the outside world. This process not only discharges heat but also consumes electricity. In a low-temperature environment, the hydrogen in the fuel cell needs additional heating of the waste heat, and the coolant also needs additional electricity to heat the waste heat.

[0003] The existing technologies of fuel cell cooling systems are divided into two categories: one is a completely independent cooling system and heating system, without energy recovery and reuse, resulting in a large amount of energy waste; the other is to use an independent cooling system and heating system, and add a driver's air-conditioning hot air waste heat utilization device to the coolant system. It can only be used in winter and after the fuel cell is fully turned on. The recovered energy is very small and there are many restrictions. Summary of the invention

[0004] In view of the problem that the existing heat recovery cooling system of fuel cell vehicles cannot efficiently utilize the waste heat of fuel cells, the present invention provides a heat recovery cooling system for fuel cell vehicles.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows:

[0006] A heat recovery cooling system for a fuel cell vehicle, comprising a fuel cell cooling unit, a drive motor cooling unit and a high-energy heat recovery cooling unit;

[0007] The fuel cell cooling unit includes a fuel cell stack, a deionizer, a stack cooling water pump, a first port of a coupled heat exchange device, a thermostat, a heater PTC, a first port of a stack preheater and an expansion water tank;

[0008] The fuel cell stack is connected to the expansion tank, the deionizer and the thermostat respectively through cold and hot medium exchange pipes;

[0009] The cold and hot medium exchange pipes connected to the deionizer and the expansion water tank are connected to the stack cooling water pump;

[0010] The first port of the coupling heat exchange device, the heater PTC and the stack preheater are connected in parallel to the cold and hot medium exchange pipeline connecting the stack cooling water pump and the thermostat;

[0011] The drive motor cooling unit includes a second port of a stack preheater, a first port of a motor radiator, and a motor cooling pump;

[0012] The input end of the first port of the motor radiator is connected to the second port of the stack preheater through a cold and hot medium exchange pipeline;

[0013] The output end of the first port of the motor radiator is connected to the motor cooling pump pipeline;

[0014] The motor cooling pump returns to the second port of the stack preheater through the cold and hot medium exchange pipeline;

[0015] The high energy heat recovery cooling unit includes a second port of the coupling heat exchange device, a second port of the motor radiator, a turbine, a hydrogen heat exchanger, an intercooler, a boost pump and a condenser;

[0016] The output end of the second port of the coupling heat exchange device is connected to the turbine, the hydrogen heat exchanger and the input end of the condenser in sequence through cold and hot medium exchange pipelines;

[0017] The output end of the condenser is connected with the boost pump, the second port of the motor radiator, the intercooler and the input end of the second port of the coupling heat exchange device in sequence through cold and hot medium exchange pipelines.

[0018] Furthermore, an exhaust pipe is connected to the cold and hot medium exchange pipe between the fuel cell stack and the thermostat, and the exhaust pipe is connected to the expansion water tank.

[0019] Furthermore, a driving motor and a controller are arranged on a pipeline connecting the first port output end of the motor radiator and the motor cooling pump. The first port output end of the motor radiator is connected to the motor cooling pump pipeline through the motor controller and the driving motor.

[0020] Furthermore, a generator is provided on the turbine.

[0021] Furthermore, the hydrogen heat exchanger is provided with a hydrogen inlet and a hydrogen outlet of the hydrogen heat exchanger; the intercooler is provided with an intercooler air inlet and an intercooler air outlet.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] Meet the fuel cell operating temperature control and solve the emergency cold start temperature problem of the fuel cell; recycle the heat energy of the fuel cell air system to increase the power generation; recycle the low heat energy of the drive motor cooling system to increase the power generation; recycle the heat energy of the drive motor cooling system to solve the cold start problem of the fuel cell; high-energy heat recovery fuel cell cooling system waste heat, greatly increase the system power generation and improve the system efficiency; further use heat recovery to preheat the hydrogen of the fuel cell hydrogen system, improve the system efficiency and extend the system life; the system introduces turbines and generators to increase the system power generation and improve the system efficiency. The high-energy heat recovery cooling system reduces the heat dissipation load, reduces the system layout space, and improves the feasibility of the vehicle equipped with a high-power system. The integrated coupling system is beautiful and simple, and reduces costs. Using insulating fluorinated liquid medium and phase change heat transfer to improve heat exchange efficiency, reduce heat exchange area, reduce occupied space, and reduce costs. Using fluorinated liquid to isolate the intercooler and hydrogen heat exchanger, improve the insulation performance of the fuel cell system and improve system safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is an overall schematic diagram of a heat recovery cooling system for a fuel cell vehicle in an embodiment of the present invention;

[0025] Figure 2 A schematic diagram of a fuel cell cooling unit in an embodiment of the present invention;

[0026] Figure 3 Schematic diagram of a drive motor cooling unit in an embodiment of the present invention;

[0027] Figure 4 Schematic diagram of a high energy heat recovery cooling unit in an embodiment of the present invention.

[0028] Explanation of marks in the figure: 1- fuel cell stack, 2- deionizer, 3- stack cooling water pump, 4- coupling heat exchange device, 5- thermostat, 6- heater PTC, 7- stack preheater, 8- exhaust pipe, 9- expansion water tank, 10- motor radiator, 11- motor cooling pump, 12- drive motor, 13- motor controller, 14- turbine, 15- generator, 16- hydrogen heat exchanger, 17- intercooler, 18- boost pump, 19- condenser, 20- intercooler air inlet, 21- intercooler air outlet, 22- hydrogen inlet of hydrogen heat exchanger, 23- hydrogen outlet of hydrogen heat exchanger. DETAILED DESCRIPTION

[0029] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0030] like Figure 1 , 2, 3 and 4, this embodiment provides a fuel cell vehicle heat recovery cooling system, including a fuel cell cooling unit, a drive motor 12 cooling unit and a high energy heat recovery cooling unit;

[0031] The fuel cell cooling unit includes a fuel cell stack 1, a deionizer 2, a stack cooling water pump 3, a first port of a coupling heat exchange device 4, a thermostat 5, a heater PTC 6, a first port of a stack preheater 7 and an expansion water tank 9;

[0032] The fuel cell stack 1 is connected to the expansion tank 9, the deionizer 2 and the thermostat 5 respectively through cold and hot medium exchange pipes;

[0033] The cold and hot medium exchange pipes connected to the deionizer 2 and the expansion water tank 9 are connected to the stack cooling water pump 3;

[0034] The cold and hot medium exchange pipeline connecting the stack cooling water pump 3 and the thermostat 5 is connected in parallel with the first port of the coupling heat exchange device 4, the heater PTC 6 and the stack preheater 7;

[0035] The drive motor cooling unit includes a second port of a stack preheater 7, a first port of a motor radiator 10 and a motor cooling pump 11;

[0036] The first port input end of the motor radiator 10 is connected to the second port of the stack preheater 7 through a cold and hot medium exchange pipeline;

[0037] The first port output end of the motor radiator 10 is connected to the motor cooling pump 11 through a pipeline;

[0038] The motor cooling pump 11 flows back to the second port of the stack preheater 7 through the cold and hot medium exchange pipeline;

[0039] The high energy heat recovery cooling unit includes a second port of the coupling heat exchange device 4, a second port of the motor radiator 10, a turbine 14, a hydrogen heat exchanger 16, an intercooler 17, a boost pump 18 and a condenser 19;

[0040] The output end of the second port of the coupling heat exchange device 4 is connected to the turbine 14, the hydrogen heat exchanger 16 and the input end of the condenser 19 in sequence through cold and hot medium exchange pipelines;

[0041] The output end of the condenser 19 is connected to the boost pump 18, the second port of the motor radiator 10, the intercooler 17 and the input end of the second port of the coupling heat exchange device 4 in sequence through cold and hot medium exchange pipelines.

[0042] An exhaust pipe 8 is connected to the cold and hot medium exchange pipeline between the fuel cell stack 1 and the thermostat 5 , and the exhaust pipe 8 is connected to the expansion water tank 9 .

[0043] A driving motor 12 and a controller are arranged on a pipeline connecting the first port output end of the motor radiator 10 and the motor cooling pump 11. The first port output end of the motor radiator 10 is connected to the motor cooling pump 11 pipeline through a motor controller 13 and the driving motor 12.

[0044] A generator 15 is provided on the turbine 14 .

[0045] The hydrogen heat exchanger 16 is provided with a hydrogen inlet 22 and a hydrogen outlet 23 ; the intercooler 17 is provided with an intercooler air inlet 20 and an intercooler air outlet 21 .

[0046] In the following embodiments, the first port of the stack preheater 7 and the second port of the stack preheater 7 are collectively referred to as the stack preheater 7; the first port of the coupling heat exchange device 4 and the second port of the coupling heat exchange device 4 are collectively referred to as the coupling heat exchange device 4; the first port of the motor radiator 10 and the second port of the motor radiator 10 are collectively referred to as the motor radiator 10.

[0047] Fuel cell cooling unit: During the operation of the fuel cell system, the waste heat generated by the fuel cell stack 1 is transferred to the coolant, the coolant heats up, takes away the waste heat generated by the fuel cell stack 1, and flows out of the fuel cell stack 1. A part of the coolant passes through the deionizer 2, absorbs ions in the coolant to reduce conductivity, and then flows to the stack cooling water pump 3; the other part of the coolant flows directly to the stack cooling water pump 3. Under the power of the stack cooling water pump 3, the coolant is divided into two paths. One path passes through the stack preheater 7, with a small temperature change, and then is heated by the heater PTC6, and flows to the small circulation inlet of the thermostat 5 as a high-temperature coolant; the other coolant passes through the coupling heat exchange device 4, transfers heat to the high-energy heat recovery cooling system, and the coolant temperature is reduced, and flows to the large circulation inlet of the thermostat 5 as a low-temperature coolant. After the thermostat 5 is mixed and controlled, it flows back into the fuel cell stack 1 through the outlet of the thermostat 5, and repeats the cycle. There is air or other gas in the system through the exhaust pipe 8 into the expansion water tank 9, and is discharged from the expansion water tank 9 after precipitation. In this process, the fuel cell stack 1 generates a large amount of waste heat, which is recycled and utilized through the coupled heat exchange device 4, and the stack preheater 7 recovers part of the heat of the cooling system of the drive motor 12, thereby recovering waste heat with high capacity, greatly improving the system efficiency. In addition, in the fuel cell air system, the high-temperature air at the compressor outlet enters the intercooler 17 through the air inlet of the intercooler 17, and the heat is transferred to the fluorinated liquid at the cold end of the intercooler 17 to recover the heat. After the cooled air flows out from the air outlet of the intercooler 17, it enters the fuel cell system for chemical reaction. In the fuel cell hydrogen system, the low-temperature hydrogen enters the hydrogen heat exchanger 16 through the hydrogen inlet of the hydrogen heat exchanger 16, and uses the high-energy heat recovery cooling system to recover the heat and then heat it to the set temperature, and enters the fuel cell hydrogen system through the hydrogen outlet of the hydrogen heat exchanger 16 for chemical reaction. The above process recovers waste heat with high energy multiple times, greatly improving the system efficiency.

[0048] Fuel cell cooling unit: In a low-temperature environment, the driver starts the vehicle and drives the motor 12 to generate waste heat, which passes through the stack preheater 7 to heat the fuel cell coolant temperature. At this time, the fuel cell system is started, the thermostat 5 is adjusted, the small cycle is fully opened, and the large cycle is closed. Under the power of the stack cooling water pump 3, the coolant flows into the stack preheater 7 for heating. There is no need to turn on the heater PTC6 additionally, reducing energy consumption. After the coolant is heated by the stack preheater 7, it passes through the heater PTC6, enters the thermostat 5, and then re-enters the fuel cell stack 1. Until the fuel cell stack 1 is heated to the set temperature, the fuel cell system starts to operate. This process meets the cold start requirements of the fuel cell system and does not require additional electrical energy, thereby greatly improving the system efficiency.

[0049] Fuel cell emergency cold start unit: Under special circumstances, when the drive motor 12 is not running or the coolant temperature of the drive motor 12 has not reached the required temperature, the fuel cell needs to be emergency cold started. At this time, turn on the heater PTC6 to consume part of the electric energy, heat the fuel cell coolant, increase the temperature, adjust the thermostat 5, fully open the small cycle, and close the large cycle. Under the power of the stack cooling water pump 3, the coolant flows into the stack preheater 7, and the heater PTC6 is turned on for heating. After being heated by the heater PTC6, the coolant passes through the thermostat 5 and re-enters the fuel cell stack 1. Until the fuel cell stack 1 is heated to the set temperature, the fuel cell system starts to operate.

[0050] Drive motor cooling unit: During the operation of the vehicle, the drive motor 12 and the motor controller 13 have high power and generate a large amount of waste heat. After the drive motor 12 coolant is cooled by heat exchange, the coolant is heated. The temperature of the heated coolant is relatively low and is not easy to be directly recovered. Therefore, the drive motor 12 coolant is pressurized by the motor cooling pump 11, first passes through the stack preheater 7 to absorb part of the heat of the fuel cell cooling system, raises the temperature, and then passes through the motor radiator 10 for heat exchange, and transfers the heat to the high-energy heat recovery cooling system. The temperature of the drive motor 12 coolant is reduced, and then returns to the drive motor 12 and the motor controller 13 for cooling and heat exchange. This process recovers the waste heat of the drive motor 12 and the motor controller 13, and further recovers part of the waste heat of the fuel cell cooling system, greatly improving the system efficiency.

[0051] High-energy heat recovery cooling unit: The cooling medium of this system uses insulating two-phase medium fluorinated liquid. The low-temperature liquid fluorinated liquid is pressurized by the booster pump 18 and is divided into two paths. One path enters the motor radiator 10 to absorb the waste heat of the cooling system of the drive motor 12. Because the temperature of the heat medium is not high, the low-temperature liquid fluorinated liquid is heated and becomes a high-temperature liquid fluorinated liquid; the other part enters the fuel cell air system intercooler 17 to cool the fuel cell air, absorb the waste heat of the fuel cell air system, and become a high-temperature liquid fluorinated liquid. After the two paths of fluorinated liquid are collected and mixed, they enter the coupling heat exchange device 4, and are further heated after absorbing the waste heat of the fuel cell cooling system. The temperature rises to above the boiling point, and violent boiling heat exchange is carried out to produce a large amount of high-temperature and high-pressure gaseous fluorinated liquid. The high-temperature and high-pressure gaseous fluorinated liquid enters the turbine 14, drives the turbine 14 to rotate, and converts thermal energy into mechanical energy. The rotation of the turbine 14 drives the generator 15 to rotate, and the mechanical energy is converted into electrical energy, which increases the system power generation power and greatly improves the system efficiency. After passing through the turbine 14, the temperature and pressure of the fluorinated liquid are reduced, and it becomes a high-temperature, low-pressure fluorinated liquid gas. Then, it is heat-exchanged through the hydrogen heat exchanger 16 to heat the hydrogen in the fuel cell hydrogen system, thereby improving the system efficiency and lifespan, and further reducing the temperature of the gaseous fluorinated liquid. At this time, the low-temperature, low-pressure gaseous fluorinated liquid enters the condenser 19, and the small amount of unrecovered waste heat is discharged into the atmosphere. The low-temperature, low-pressure gaseous fluorinated liquid is condensed and becomes a low-temperature, low-pressure liquid fluorinated liquid again. The low-temperature, low-pressure liquid fluorinated liquid enters the booster pump 18 again for pressurization, and the cycle repeats. This process recycles the waste heat of the cooling system of the drive motor 12, recycles the waste heat of the fuel cell air system, recycles the waste heat of the fuel cell cooling system, utilizes the unrecovered part of the waste heat to heat the fuel cell hydrogen system, further utilizes the waste heat, and the high-energy heat recovery cooling system increases the system power generation, greatly improving the system efficiency.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] Meet the fuel cell operating temperature control and solve the emergency cold start temperature problem of the fuel cell; recycle the heat energy of the fuel cell air system to increase the power generation; recycle the low heat energy of the drive motor cooling system to increase the power generation; recycle the heat energy of the drive motor cooling system to solve the cold start problem of the fuel cell; high-energy heat recovery fuel cell cooling system waste heat, greatly increase the system power generation, improve system efficiency; further use heat recovery to preheat the hydrogen of the fuel cell hydrogen system, improve system efficiency, and extend system life; the system introduces a turbine 14 and a generator 15 to increase the system power generation and improve system efficiency. The high-energy heat recovery cooling system reduces the heat dissipation load, reduces the system layout space, and improves the feasibility of the vehicle carrying a high-power system. The integrated coupling system is beautiful and simple, and reduces costs. Using insulating fluorinated liquid medium and phase change heat transfer to improve heat exchange efficiency, reduce heat exchange area, reduce occupied space, and reduce costs. Using fluorinated liquid to isolate the intercooler 17 and the hydrogen heat exchanger 16, the insulation performance of the fuel cell system is improved, and the system safety is improved.

[0054] The above is a detailed introduction to a fuel cell vehicle heat recovery cooling system provided by the present application. The description of the specific embodiment is only used to help understand the method and its core idea of ​​the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A heat recovery cooling system for a fuel cell vehicle, characterized in that: It includes a fuel cell cooling unit, a drive motor (12) cooling unit and a high energy heat recovery cooling unit; The fuel cell cooling unit comprises a fuel cell stack (1), a deionizer (2), a stack cooling water pump (3), a first port of a coupling heat exchange device (4), a thermostat (5), a heater PTC (6), a first port of a stack preheater (7) and an expansion water tank (9); The fuel cell stack (1) is connected to the expansion water tank (9), the deionizer (2) and the thermostat (5) respectively through cold and hot medium exchange pipes; The cold and hot medium exchange pipes connected to the deionizer (2) and the expansion water tank (9) are connected to the stack cooling water pump (3); The first port of the coupling heat exchange device (4), the PTC heater (6) and the stack preheater (7) are connected in parallel to the cold and hot medium exchange pipeline connecting the stack cooling water pump (3) and the thermostat (5); The drive motor cooling unit comprises a second port of a stack preheater (7), a first port of a motor radiator (10) and a motor cooling pump (11); The first port input end of the motor radiator (10) is connected to the second port of the stack preheater (7) via a cold and hot medium exchange pipeline; The first port output end of the motor radiator (10) is connected to a pipeline of a motor cooling pump (11); The motor cooling pump (11) returns to the second port of the stack preheater (7) through the cold and hot medium exchange pipeline; The high energy heat recovery cooling unit comprises a second port of a coupling heat exchange device (4), a second port of a motor radiator (10), a turbine (14), a hydrogen heat exchanger (16), an intercooler (17), a boost pump (18) and a condenser (19); The second port output end of the coupling heat exchange device (4) is connected to the turbine (14), the hydrogen heat exchanger (16) and the input end of the condenser (19) in sequence through cold and hot medium exchange pipelines; The output end of the condenser (19) is connected to the booster pump (18), the second port of the motor radiator (10), the intercooler (17) and the input end of the second port of the coupling heat exchange device (4) in sequence through cold and hot medium exchange pipelines.

2. A fuel cell vehicle heat recovery cooling system according to claim 1, characterized in that: An exhaust pipe (8) is connected to the cold and hot medium exchange pipeline between the fuel cell stack (1) and the thermostat (5), and the exhaust pipe (8) is connected to the expansion water tank (9).

3. A fuel cell vehicle heat recovery cooling system according to claim 2, characterized in that: A driving motor (12) and a controller are provided on a pipeline connecting the first port output end of the motor radiator (10) and the motor cooling pump (11).

4. A fuel cell vehicle heat recovery cooling system according to claim 3, characterized in that: A generator (15) is provided on the turbine (14).

5. A fuel cell vehicle heat recovery cooling system according to claim 4, characterized in that: The hydrogen heat exchanger (16) is provided with a hydrogen heat exchanger hydrogen inlet (22) and a hydrogen heat exchanger hydrogen outlet (23); the intercooler (17) is provided with an intercooler air inlet (20) and an intercooler air outlet (21).

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