Vehicle-mounted fuel cell cooling system

Abstract

The utility model discloses a vehicle-mounted fuel cell cooling system, and relates to the technical field of vehicle-mounted fuel cells, the vehicle-mounted fuel cell cooling system comprises a cell stack, a cooling unit and a pressure relief unit, the cooling unit comprises a cooling pump and a water tank, the pressure relief unit comprises a control valve and a three-way valve, and a liquid phase channel is arranged in the control valve; the radiator, the liquid phase channel, the cooling pump, the cell stack, the three-way valve and the radiator are communicated in sequence to form an external circulating cooling water path; the liquid phase channel, the cooling pump, the cell stack, the three-way valve, the liquid phase channel, the cooling pump and the cell stack are communicated in sequence to form an internal circulation cooling water path; the outlet of the water tank is communicated to the upstream of the liquid phase channel, and the communicated position of the outlet and the liquid phase channel is located at the downstream of the radiator and the three-way valve. The vehicle-mounted fuel cell cooling system is based on the control valve and the three-way valve, and the effects of automatic pressure relief and static pressure control of a fuel cell system in the long-term parking process of a vehicle are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicle-mounted fuel cells, in particular to a vehicle-mounted fuel cell cooling system. Background Art

[0002] At present, the cooling system of vehicle-mounted fuel cells is mainly composed of water pumps, PTCs, radiators, water tanks, three-way valves and pipelines. When the cooling system is shut down or running, the inlet and outlet of the fuel cell stack cooling channel are directly connected to the radiator and water tank. Existing fuel cell engines are mostly used in commercial vehicles, such as 49T heavy trucks. In these models, the fuel cell engine is generally arranged in the middle of the chassis at the bottom of the front of the vehicle, and the radiator and water tank of the fuel cell are arranged on the top of the hydrogen storage system, and its horizontal height is much higher than the fuel cell engine. The radiator and water tank at a high position in the space will generate static pressure on the engine stack inlet, and the static pressure is about 30kPa.

[0003] During the operation of the vehicle, the fuel cell group can control the pressure parameters of the hydrogen flow channel and the air flow channel in real time to ensure that the pressure difference between the stack cooling flow channel and the air flow channel or the hydrogen flow channel is controlled within a reasonable range. However, after the vehicle is parked, the pressure difference between the stack cooling flow channel and the air flow channel or the hydrogen flow channel cannot be controlled due to the long-term shutdown of the cooling system. At this time, the static pressure generated by the high-positioned radiator and water tank on the stack inlet of the engine will cause the coolant inside the stack to continue to leak slightly. The coolant dedicated to fuel cells generally contains ethylene glycol and other additives and has a certain viscosity. The leaking coolant will adhere to the proton exchange membrane, causing the continuous attenuation of the stack performance. Utility Model Content

[0004] The purpose of the utility model is to provide a vehicle-mounted fuel cell cooling system which can better cut off the liquid pressure of the external cooling water channel and timely release the static pressure inside the fuel cell stack, so as to solve the problem that the fuel cell stack is subjected to the static pressure applied by the cooling flow channel when the vehicle is parked.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A vehicle-mounted fuel cell cooling system comprises a battery stack, a cooling unit, and a pressure relief unit, wherein the cooling unit comprises a cooling pump, a radiator, and a water tank, and the pressure relief unit comprises a control valve and a three-way valve, wherein a liquid phase channel is arranged in the control valve;

[0007] The radiator, liquid phase channel, cooling pump, battery stack, three-way valve and radiator are connected in sequence to form an external circulation cooling water circuit;

[0008] The radiator, the liquid phase channel, the cooling pump, the battery stack, the three-way valve, the liquid phase channel, the cooling pump, and the battery stack are connected in sequence to form an internal circulation cooling water circuit;

[0009] The outlet of the water tank is connected to the upstream of the liquid phase channel, and the communication position between the outlet and the liquid phase channel is located downstream of the radiator and the three-way valve.

[0010] In this cooling system, the cooling pump provides circulation power for the entire vehicle fuel cell cooling system. The negative pressure generated by the cooling pump extracts the coolant from the radiator. After the coolant passes through the liquid phase channel of the control valve, it passes through the cooling pump and enters the fuel cell stack. After the coolant comes out of the battery stack, it is divided into two paths through the three-way valve. One path returns to the radiator for cooling, forming an external circulation cooling water path. The external circulation cooling water path is generally the same as the battery stack of the fuel cell that cools the fuel cell during normal operation of the vehicle; the other path is controlled by the three-way valve to open the water path to the liquid phase channel of the control valve, and returns to the cooling pump through the liquid phase channel, and enters the battery stack of the fuel cell again, forming an internal circulation cooling water path. The internal circulation cooling water path is generally used to quickly increase the temperature of the battery stack when the vehicle is just started. When the water path of the cooling system has a reduced pressure or insufficient flow, the cooling water stored in the water tank is supplemented to the external circulation cooling water path and the internal circulation cooling water path of the cooling system through the outlet of the water tank under the action of gravity.

[0011] When the fuel cell system receives a shutdown command and enters a shutdown state, the control valve and the three-way valve cut off the connection between the fuel cell stack and the water circuit, so that the liquid pressure between the battery stack and the external water circuit is retained by the control valve and the three-way valve, and only water in the pipes connecting the battery stack and the control valve and the three-way valve remains. The volume of this water is very small and it is normally retained in the pipe, which will not cause excessive static pressure on the battery stack, thereby greatly reducing the pressure of the external water circuit of the battery stack of the fuel-electric system.

[0012] In some embodiments, a first gas phase branch for releasing the gas pressure inside the battery stack is connected between the outlet of the battery stack and the inlet of the three-way valve, and the first gas phase branch is connected to the inside of the water tank.

[0013] In some embodiments, a pressure relief port for releasing the gas pressure inside the external circulation cooling water circuit is provided in the radiator, and the pressure relief port is connected to a second gas phase branch, and the second gas phase branch is connected to the interior of the water tank.

[0014] The gas in the cooling system flows along the external circulation cooling water circuit and the internal circulation cooling water circuit, and is divided into two paths at the outlet of the battery stack. One path of gas flows to the inside of the water tank through the gas outlet of the battery stack itself, and the other path of gas flows to the inside of the water tank through the external circulation cooling water circuit via the radiator, thereby reducing the pressure inside the water tank.

[0015] In some embodiments, a one-way valve that limits the flow of gas from the battery stack to the water tank is provided in the first gas phase branch. The one-way valve provided at the front end of the battery stack exhaust has a pressure cut-off function at both ends of the one-way valve. By utilizing the mechanical characteristics of the one-way valve, it is possible to effectively block the external pressure while reducing the overall cost of controlling the static pressure of the cooling system.

[0016] In some embodiments, an exhaust port for exhausting gas is provided in the control valve, and a sensor for monitoring the internal air pressure of the pipeline between the inlet of the battery stack and the cooling pump is provided at the inlet of the battery stack, and the sensor is connected to the control valve.

[0017] Under the cut-off action of the control valve and the three-way valve, the external pressure of the battery stack is cut off, and the residual water volume left in the pipeline between the battery stack inlet and the cooling pump will not change. The liquid volume remains constant, but the hydraulic pressure inside the battery stack is still consistent with the hydraulic pressure before the cut-off. By setting a sensor in the pipeline between the battery stack inlet and the cooling pump, it is possible to monitor the pressure state of the pipeline between the battery stack inlet and the cooling pump to determine whether the battery stack needs to be depressurized in the gas phase. When the pressure of the pipeline between the battery stack inlet and the cooling pump reaches the set value, the control valve can instantly open and close the exhaust port to connect the inside of the battery stack with the external atmosphere, so that the gas pressure inside the battery stack drops to the atmospheric standard, and the static pressure of the pipeline between the battery stack inlet and the cooling pump is controlled. When the vehicle is stopped, the pressure state of the pipeline between the battery stack inlet and the cooling pump is regularly monitored by the sensor, so as to ensure that the internal static pressure of the battery stack is always within a reasonable range during the long-term parking of the vehicle, so as to avoid the leakage of coolant inside the battery stack caused by the external water channel static pressure caused by the water tank due to the long-term parking of the vehicle, resulting in the degradation of the battery stack performance.

[0018] In some embodiments, a heater is provided between the three-way valve and the liquid phase channel of the control valve. When the heater is used to enable the internal circulation cooling water circuit of the vehicle, the internal temperature of the battery stack can be quickly increased, so that the fuel cell system can be started normally.

[0019] Compared with the prior art, the vehicle-mounted fuel cell cooling system of the utility model has the following beneficial effects:

[0020] (1) This cooling system is based on a control valve and a three-way valve to achieve the effect of automatic pressure relief and static pressure control of the fuel cell system during long-term parking of the vehicle;

[0021] (2) Compared with the existing fuel cell cooling system, this cooling system utilizes the non-compressible property of liquid and uses the control valve with its own pressure relief function, which reduces the layout of redundant pipelines such as the pressure relief tank, and makes the layout of the cooling system simpler;

[0022] (3) When the vehicle is stopped, the cooling system regularly monitors the pressure status of the pipeline between the battery stack inlet and the cooling pump through sensors, thereby ensuring that the internal static pressure of the battery stack remains within a reasonable range during long-term parking of the fuel cell system, thereby avoiding the situation where the external water static pressure caused by the water tank causes the coolant to leak inside the battery stack due to long-term parking of the vehicle, resulting in degradation of the battery stack performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the connection of the cooling system in the embodiment of the utility model;

[0024] Figure 2 It is a connection diagram of the cooling system in the embodiment of the utility model.

[0025] In the figure, 1. battery stack; 2. cooling pump; 3. radiator; 4. water tank; 5. control valve; 6. three-way valve; 7. first gas phase branch; 8. one-way valve; 9. second gas phase branch; 10. deionization filter; 11. sensor; 12. heater. DETAILED DESCRIPTION

[0026] The following is a further detailed description of the specific implementation of the present invention in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0027] In the description of the present utility model, it should be understood that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. The terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.

[0028] In the description of the present invention, it should be understood that the terms "height", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like used in the present invention to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0029] In the description of the present invention, it should be understood that the terms "first" and "second" are used in the present invention for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0030] Example 1

[0031] like Figure 1 As shown, a vehicle-mounted fuel cell cooling system preferably implemented in the present utility model includes a battery stack 1, a cooling unit, and a pressure relief unit, wherein:

[0032] The cooling unit includes a cooling pump 2, a radiator 3 and a water tank 4, and the water tank 4 is located at a high position at the vehicle level;

[0033] The pressure relief unit includes a control valve 5 and a three-way valve 6. The control valve 5 can select a multifunctional stop valve. The function of the multifunctional stop valve itself is utilized to achieve the control effect of the control valve 5, so as to reduce the cost of controlling the static pressure of the cooling system. A liquid phase channel and an exhaust port for exhausting gas are arranged in the control valve 5; the three-way valve 6 can select an electric control valve to control the connectivity of the various passages of the valve 5.

[0034] In this cooling system, there are a liquid phase circuit and a gas phase circuit, wherein:

[0035] The radiator 3, the liquid phase channel of the control valve 5, the cooling pump 2, the battery stack 1, the three-way valve 6, and the radiator 3 are connected in sequence to form an external circulation cooling water circuit;

[0036] The radiator 3, the liquid phase channel of the control valve 5, the cooling pump 2, the battery stack 1, the three-way valve 6, the liquid phase channel of the control valve 5, the cooling pump 2, and the battery stack 1 are connected in sequence to form an internal circulation cooling water circuit;

[0037] A first gas phase branch 7 for releasing the gas pressure inside the battery stack 1 is connected between the outlet of the battery stack 1 and the inlet of the three-way valve 6. The first gas phase branch 7 is the exhaust structure of the battery stack 1 itself. The first gas phase branch 7 is connected to the inside of the water tank 4, and a one-way valve 8 is provided in the first gas phase branch 7 to limit the flow of gas from the battery stack 1 to the water tank 4.

[0038] A pressure relief port for releasing the gas pressure inside the external circulation cooling water circuit is provided in the radiator 3. The pressure relief port is connected to a second gas phase branch 9, which is connected to the interior of the water tank 4. A deionizing filter 10 is provided on the second gas phase branch 9 to filter the gas discharged from the radiator 3.

[0039] In this embodiment 1, the outlet of the water tank 4 is connected to the upstream of the liquid phase channel of the control valve 5 , and the communication position between the outlet and the liquid phase channel of the control valve 5 is downstream of the radiator 3 and the three-way valve 6 .

[0040] In addition, a sensor 11 is provided at the inlet of the battery stack 1 to monitor the internal air pressure of the pipeline between the inlet of the battery stack 1 and the cooling pump 2. The sensor 11 is connected to the control valve 5 so that the control valve 5 can control the opening of its own exhaust port according to the pressure data monitored by the sensor 11.

[0041] The working process of the vehicle fuel cell cooling system of this embodiment is as follows:

[0042] In the liquid phase environment, the negative pressure generated by the cooling pump 2 extracts the coolant from the radiator 3. After the coolant passes through the liquid phase channel of the control valve 5, it passes through the cooling pump 2 and enters the battery stack 1 of the fuel cell. After the coolant comes out of the battery stack 1, it is divided into two paths through the three-way valve 6. One path returns to the radiator 3 for cooling and circulates in the external circulation cooling water circuit; the other path is controlled by the three-way valve 6 to open the water channel to the liquid phase channel of the control valve 5, returns to the cooling pump 2 through the liquid phase channel, and enters the battery stack 1 of the fuel cell again, and circulates in the internal circulation cooling water circuit.

[0043] When the pressure in the water circuit of the cooling system decreases or the flow is insufficient, the cooling water stored in the water tank 4 is replenished to the external circulation cooling water circuit and the internal circulation cooling water circuit of the cooling system through the outlet of the water tank 4 under the action of gravity.

[0044] In the gas phase environment, the gas of the cooling system flows along the external circulation cooling water circuit and the internal circulation cooling water circuit, and is divided into two paths at the outlet of the battery stack 1. One path of gas flows to the inside of the water tank 4 through the first gas phase branch 7 of the battery stack 1 itself, and the other path of gas flows to the inside of the water tank 4 through the external circulation cooling water circuit and the second gas phase branch 9, thereby reducing the pressure inside the water tank 4.

[0045] When the fuel cell system receives a shutdown command, the fuel cell system enters a shutdown state, and the control valve 5 and the three-way valve 6 cut off the connection between the fuel cell stack 1 and the water circuit, so that the liquid pressure between the fuel cell stack 1 and the external water circuit is retained by the control valve 5 and the three-way valve 6.

[0046] Subsequently, the pressure state of the pipeline between the inlet of the battery stack 1 and the cooling pump 2 is monitored by the sensor 11 disposed in the pipeline between the inlet of the battery stack 1 and the cooling pump 2, and it is determined whether it is necessary to perform gas phase pressure relief on the battery stack 1. When the pressure of the pipeline between the inlet of the battery stack 1 and the cooling pump 2 reaches the set value, the control valve 5 instantly opens and closes the exhaust port, connects the pipeline between the inlet of the battery stack 1 and the cooling pump 2 with the external atmospheric environment, and controls the static pressure of the pipeline between the inlet of the battery stack 1 and the cooling pump 2. When the vehicle is stopped, the pressure state of the pipeline between the inlet of the battery stack 1 and the cooling pump 2 is regularly monitored by the sensor 11, so as to ensure that the internal static pressure of the battery stack 1 is always within a reasonable range during the long-term parking of the fuel cell system, so as to avoid the leakage of coolant inside the battery stack 1 caused by the external water channel static pressure caused by the water tank 4 due to the long-term parking of the vehicle, resulting in the performance degradation of the battery stack 1.

[0047] Example 2

[0048] like Figure 2 As shown, the difference between the present embodiment 2 and the embodiment 1 is that, in the cooling system of the present embodiment 2, a heater 12 is provided between the three-way valve 6 and the liquid phase channel of the control valve 5. When the internal circulation cooling water circuit of the vehicle is activated by the heater 12, the internal temperature of the battery stack 1 can be quickly increased, so that the fuel cell system can be started normally.

[0049] In summary, the embodiment of the utility model provides a vehicle-mounted fuel cell cooling system, which is based on the control valve 5 and the three-way valve 6 to achieve the effect of automatic pressure relief and static pressure control of the fuel cell system during long-term parking of the vehicle. Compared with the existing fuel cell cooling system, the present cooling system utilizes the characteristic that the liquid is not compressed and uses the pressure relief function of the control valve 5, thereby reducing the arrangement of redundant pipelines such as the pressure relief box, and the layout of the cooling system is simpler; moreover, when the vehicle is stopped, the present cooling system regularly monitors the pressure state of the pipeline between the inlet of the battery stack 1 and the cooling pump 2 through the sensor 11, thereby ensuring that the internal static pressure of the battery stack 1 is always within a reasonable range during the long-term parking of the vehicle, thereby avoiding the leakage of coolant inside the battery stack 1 due to the external water channel static pressure caused by the water tank 4 due to the long-term parking of the vehicle, resulting in the performance degradation of the battery stack 1.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principle of the present invention. These improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A vehicle-mounted fuel cell cooling system, characterized in that: It includes a battery stack, a cooling unit, and a pressure relief unit, wherein the cooling unit includes a cooling pump, a radiator, and a water tank, and the pressure relief unit includes a control valve and a three-way valve, wherein a liquid phase channel is provided in the control valve; The radiator, liquid phase channel, cooling pump, battery stack, three-way valve and radiator are connected in sequence to form an external circulation cooling water circuit; The liquid phase channel, cooling pump, battery stack, three-way valve and liquid phase channel are connected in sequence to form an internal circulation cooling water circuit; The outlet of the water tank is connected to the upstream of the liquid phase channel, and the communication position between the outlet and the liquid phase channel is located downstream of the radiator and the three-way valve.

2. The vehicle-mounted fuel cell cooling system according to claim 1, characterized in that: A first gas phase branch for releasing the gas pressure inside the battery stack is connected between the outlet of the battery stack and the inlet of the three-way valve, and the first gas phase branch is connected to the inside of the water tank.

3. The vehicle-mounted fuel cell cooling system according to claim 2, characterized in that: A one-way valve is provided in the first gas phase branch for limiting the flow of gas from the battery stack to the water tank.

4. The vehicle-mounted fuel cell cooling system according to claim 1, characterized in that: The radiator is provided with a pressure relief port for releasing the gas pressure inside the external circulation cooling water circuit, and the pressure relief port is connected to a second gas phase branch, and the second gas phase branch is connected to the inside of the water tank.

5. The vehicle-mounted fuel cell cooling system according to claim 1, characterized in that: The control valve is provided with an exhaust port for exhausting gas, and the inlet of the battery stack is provided with a sensor for monitoring the internal air pressure of the pipeline between the inlet of the battery stack and the cooling pump, and the sensor is connected to the control valve.

6. The vehicle-mounted fuel cell cooling system according to claim 1, characterized in that: A heater is provided between the three-way valve and the liquid phase channel of the control valve.

7. The vehicle-mounted fuel cell cooling system according to claim 1, characterized in that: The control valve is a multifunctional stop valve.

8. The vehicle-mounted fuel cell cooling system according to claim 1, characterized in that: The three-way valve is an electrically controlled valve.

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