阅读说明：本技术 一种燃料电池冷却循环系统 (Cooling circulation system of fuel cell ) 是由 马天才 于 2021-08-06 设计创作，主要内容包括：本发明涉及一种燃料电池冷却循环系统,包括电堆、空气回路、冷却回路和压力回路；空气回路包括空压机,空压机压缩的空气自电堆的空气入口通入电堆,自电堆的空气出口排出电堆；冷却回路包括膨胀水箱和水泵,冷却液在水泵的作用下通入电堆,并自电堆回流至水泵进水口,膨胀水箱为冷却回路补充冷却液；压力回路包括输气管和单向阀,输气管连接电堆的空气出口和膨胀水箱,单向阀布置在电堆的空气出口与膨胀水箱之间。与现有技术相比,本发明将电堆空气出口处具有一定压力的气体通入膨胀水箱,降低了燃料电池对水泵扬程的需要,降低了燃料电池的成本,且较小扬程的水泵的功率也较小,从而增大了燃料电池的系统净输出功率。(The invention relates to a fuel cell cooling circulation system, which comprises a galvanic pile, an air loop, a cooling loop and a pressure loop, wherein the galvanic pile is arranged on the surface of the fuel cell; the air loop comprises an air compressor, air compressed by the air compressor is introduced into the electric pile from an air inlet of the electric pile, and is discharged out of the electric pile from an air outlet of the electric pile; the cooling circuit comprises an expansion water tank and a water pump, cooling liquid is introduced into the electric pile under the action of the water pump and flows back to a water inlet of the water pump from the electric pile, and the expansion water tank supplements the cooling liquid for the cooling circuit; the pressure loop comprises a gas pipe and a one-way valve, the gas pipe is connected with the air outlet of the galvanic pile and the expansion water tank, and the one-way valve is arranged between the air outlet of the galvanic pile and the expansion water tank. Compared with the prior art, the invention leads the gas with a certain pressure at the air outlet of the pile into the expansion water tank, reduces the requirement of the fuel cell on the lift of the water pump, reduces the cost of the fuel cell, and has smaller power of the water pump with smaller lift, thereby increasing the net output power of the system of the fuel cell.)

1. A fuel cell cooling circulation system is characterized by comprising a stack (1), an air loop, a cooling loop and a pressure loop;

the air loop comprises an air compressor (2), the air compressor (2) is used for compressing air, the compressed air is introduced into the electric pile (1) from an air inlet of the electric pile (1), and the compressed air in the electric pile (1) is discharged out of the electric pile (1) from an air outlet of the electric pile (1);

the cooling circuit comprises an expansion water tank (4) and a water pump (5), cooling liquid is introduced into the galvanic pile (1) under the action of the water pump (5) and flows back to a water inlet of the water pump (5) from the galvanic pile (1), and the expansion water tank (4) is used for supplementing the cooling liquid to the cooling circuit;

the pressure circuit comprises an air pipe and a one-way valve (42), one end of the air pipe is connected to an air outlet of the galvanic pile (1), the other end of the air pipe is connected to the expansion water tank (4), and the one-way valve (42) is arranged between the air outlet of the galvanic pile (1) and the expansion water tank (4) and used for conducting the air outlet to the expansion water tank (4) and blocking the expansion water tank (4) to the air outlet.

2. The fuel cell cooling circulation system according to claim 1, wherein the air loop further comprises an air inlet pipe, the air inlet pipe is connected with the air compressor (2) and an air inlet of the electric pile (1), and air compressed by the air compressor (2) is introduced into the electric pile (1) through the air inlet pipe.

3. The fuel cell cooling circulation system of claim 2, wherein the air circuit further comprises an exhaust pipe, the exhaust pipe is connected with an air outlet of the stack (1), compressed air in the stack (1) is exhausted through the exhaust pipe, the exhaust pipe is provided with a pressure regulating valve (3), and the pressure regulating valve (3) is used for regulating air pressure of the air circuit.

4. A fuel cell cooling circulation system according to claim 3, wherein one end of the gas pipe is connected to the exhaust pipe, and the connection of the gas pipe and the exhaust pipe is located upstream of the pressure regulating valve (3).

5. A fuel cell cooling circulation system according to claim 1, wherein the piping between the air outlet of the stack (1) and the expansion tank (4) is inclined upward or vertically upward.

6. A fuel cell cooling circulation system according to claim 5, further comprising a support structure for supporting a conduit between the air outlet of the stack (1) to the expansion tank (4).

7. The cooling circulation system of the fuel cell according to claim 1, wherein the cooling loop further comprises a water inlet pipe, a water outlet pipe and a water replenishing pipe, a water outlet of the water pump (5) is connected to a cooling liquid inlet of the stack (1) through the water outlet pipe, cooling liquid flowing out of a cooling liquid outlet of the stack (1) is cooled and then flows back to a water inlet of the water pump (5) through the water inlet pipe, and the expansion water tank (4) is connected to a water inlet of the water pump (5) through the water replenishing pipe to replenish the cooling liquid for the cooling loop.

8. A fuel cell cooling circulation system according to claim 1, wherein the expansion tank (4) comprises a tank body (43) and a pressure cover (41), a water supply pipe is connected to the tank body (43), and a pressure relief port is provided on the pressure cover (41).

9. A fuel cell cooling circulation system according to claim 8, wherein the check valve (42) is integrated in a tank (43) of the expansion tank (4).

10. A fuel cell cooling circulation system according to claim 9, wherein the pressure cover (41) is provided at the top of the tank (43), the check valve (42) is integrated in the side wall of the tank (43), and the check valve (42) is located above the highest liquid level in the tank (43) of the expansion tank (4).

Technical Field

The invention relates to the technical field of fuel cells, in particular to a cooling circulation system of a fuel cell.

Background

In a fuel cell system, in order to ensure that a stack can operate in a relatively ideal state, a certain pressure difference is generally required to be maintained between a cooling side of the stack and an anode and a cathode of the stack, so that the mutual permeation of hydrogen, air and cooling liquid caused by the overlarge pressure difference between the cooling side of the stack and the anode and the cathode of the stack is avoided.

At present, the system power of the fuel cell is increased, and a water pump with a relatively large lift is required to ensure the pressure of the cooling side. However, the arrangement of a water pump with a large head causes the following problems: the power of the water pump is increased, resulting in a reduction in the net output power of the entire fuel cell system; the high-lift water pump has high cost, which can increase the production cost of the fuel cell; the selectable models of the large-lift water pump are fewer, so that the fuel cell system is difficult to match.

Chinese patent CN210668556U discloses a pressure control system for cooling water of a fuel cell engine, which basically adopts the idea that compressed air at the inlet of a galvanic pile is introduced into an expansion water tank, so that the pressure at the inlet of a water pump is increased, and the power consumed by the water pump is reduced. The system has the advantages of low energy consumption, good pressure control stability and the like, but still has the defects in practical application: after compressed air is introduced into the expansion water tank, the expansion water tank has certain pressure, and when the air compressor stops running or the pressure of an air path is smaller than that of the expansion water tank, water and gas in the expansion water tank can flow back into the air path, so that the service life of the fuel cell is influenced; compressed air passes through the gas-supply pipe and lets in expansion tank, and along with the increase of pile power, the pressure of pile entry (air compressor machine export) also can show the increase, needs to set up regulation atmospheric pressure such as pressure regulating parts on the gas-supply pipe, has leaded to fuel cell system's cost higher like this, has occupied certain volume and space moreover, is unfavorable for integrating the setting.

Disclosure of Invention

The present invention is directed to a cooling cycle system for a fuel cell, which overcomes the above-mentioned drawbacks of the prior art.

The purpose of the invention can be realized by the following technical scheme:

a fuel cell cooling circulation system comprises a stack, an air loop, a cooling loop and a pressure loop;

the air loop comprises an air compressor, the air compressor is used for compressing air, the compressed air is introduced into the cathode of the galvanic pile from an air inlet of the galvanic pile, and the compressed air in the galvanic pile is discharged out of the galvanic pile from an air outlet of the cathode of the galvanic pile;

the cooling circuit comprises an expansion water tank and a water pump, cooling liquid is introduced into the electric pile under the action of the water pump and flows back to a water inlet of the water pump from the electric pile, and the expansion water tank is used for supplementing the cooling liquid to the cooling circuit;

the pressure loop comprises a gas pipe and a one-way valve, one end of the gas pipe is connected to an air outlet of the galvanic pile, the other end of the gas pipe is connected to the expansion water tank, and the one-way valve is arranged between the air outlet of the galvanic pile and the expansion water tank and used for conducting the air outlet to the expansion water tank and blocking the expansion water tank to the air outlet.

Further, the air loop further comprises an air inlet pipe, the air inlet pipe is connected with an air inlet of the air compressor and an air inlet of the electric pile, and air compressed by the air compressor is introduced into the electric pile through the air inlet pipe.

Furthermore, the air circuit further comprises an exhaust pipe, the exhaust pipe is connected with an air outlet of the galvanic pile, compressed air in the galvanic pile is discharged through the exhaust pipe, and the exhaust pipe is provided with a pressure regulating valve which is used for regulating air pressure of the air circuit.

Furthermore, one end of the gas pipe is connected to the exhaust pipe, and the joint of the gas pipe and the exhaust pipe is located at the upstream of the pressure regulating valve.

Furthermore, the pipeline between the air outlet of the pile and the expansion water tank is inclined upwards or vertically upwards, so that the pipeline is prevented from being bent downwards and then upwards, and the increase of flow resistance caused by the accumulation of water at the cathode outlet of the pile in the pipeline is prevented.

Further, the fuel cell cooling circulation system further comprises a support structure, and the support structure is used for supporting a pipeline from the air outlet of the electric pile to the expansion water tank.

Furthermore, cooling circuit still includes inlet tube, outlet pipe and moisturizing pipe, and the delivery port of water pump passes through outlet pipe connection to the coolant liquid entry of pile, the coolant liquid that the pile coolant liquid export flows passes through after the cooling the water inlet of inlet pipe flow return water pump, expansion tank passes through moisturizing pipe connection to the water inlet of water pump, for cooling circuit replenishment coolant liquid.

Furthermore, expansion tank includes box and pressure lid, and the moisturizing pipe is connected to the box, be equipped with the pressure release mouth on the pressure lid.

Further, the one-way valve is integrated on the tank body of the expansion water tank.

Further, the pressure lid sets up at the top of box, the check valve integration is on the lateral wall of box, and the position of check valve is higher than the highest liquid level in expansion tank's the box for the even pressurized of coolant liquid in the expansion tank, in order to avoid stirring the coolant liquid in the expansion tank.

Further, air circuit still includes filter, intercooler and humidifier, the filter sets up the upper reaches at the air compressor machine, the intercooler sets up between air compressor machine and pile, the humidifier sets up between intercooler and pile.

Compared with the prior art, the invention has the following beneficial effects:

(1) gas that has certain pressure with pile air outlet department lets in expansion tank to reduced fuel cell to the needs of water pump lift, can choose the water pump of less lift for use, the optional type scope of water pump is wide this moment, and is also cheaper for the water pump price of big lift, thereby reduced fuel cell's cost, the power of the water pump of less lift is also less, therefore the power of water pump consumption can reduce, thereby increased fuel cell's the net output of system.

(2) The expansion water tank is integrated with the one-way valve, so that water and gas in the expansion water tank can be prevented from flowing backwards, and the safety and the service life of the fuel cell system are ensured.

(3) The gas pressure of the air outlet of the pile is stable, basically no pressure fluctuation exists, the pressure transmitted to the expansion water tank also tends to be stable, and the stability of a cooling loop is facilitated, so that a pressure regulating part does not need to be arranged on a gas conveying pipe, the cost is reduced, the volume is reduced, and the integrated arrangement of a fuel system is facilitated.

(4) The flow resistance exists in the pile, when the pressure of the pile air inlet rises, the air outlet pressure of the pile correspondingly increases, however, the flow resistance of the pile is also continuously increased, so that the pressure of the pile air outlet is slowly increased, the pressure of the expansion water tank is adjusted by the flow resistance of the pile, and a pressure adjusting part does not need to be arranged on the air conveying pipe.

(5) The pipeline between the air outlet of the pile and the expansion water tank is inclined upwards or vertically upwards, so that the pipeline is prevented from being bent downwards and then upwards, and the increase of flow resistance caused by the accumulation of water at the cathode outlet of the pile in the pipeline is prevented.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a flow chart;

reference numerals: 1. the device comprises a galvanic pile, a 2 air compressor, a 3 air regulating valve, a 4 expansion water tank, a 41 pressure cover, a 42 one-way valve, a 43 box body, a 5 water pump.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views. The size and thickness of each component shown in the drawings are arbitrarily illustrated, and the present invention is not limited to the size and thickness of each component. Parts are exaggerated in the drawing where appropriate for clarity of illustration.

Example 1:

a fuel cell cooling circulation system, as shown in FIG. 1, includes a stack 1, an air circuit, a cooling circuit, and a pressure circuit;

the air loop comprises an air compressor 2, the air compressor 2 is used for compressing air, the compressed air is introduced into the galvanic pile 1 from an air inlet of the cathode of the galvanic pile 1, and the compressed air in the galvanic pile 1 is discharged out of the galvanic pile 1 from an air outlet of the cathode of the galvanic pile 1; in order to guarantee the normal work of fuel cell, air circuit still includes filter, intercooler and humidifier, and the filter setting is in the upper reaches of air compressor machine 2 for filtered air, and the intercooler setting is between air compressor machine 2 and galvanic pile 1, and the high temperature air after the compression cools down, and the humidifier setting is between intercooler and galvanic pile 1, carries out the humidification to the air, and the air after the humidification lets in galvanic pile 1 again.

The air loop also comprises an air inlet pipe and an air outlet pipe, the air inlet pipe is connected with the air inlets of the air compressor 2 and the electric pile 1, and air compressed by the air compressor 2 is introduced into the electric pile 1 through the air inlet pipe; the air outlet of air vent pipe connection pile 1, the compressed air in pile 1 discharges through the air vent pipe, installs air-vent valve 3 (be the backpressure valve) on the air vent pipe, and air-vent valve 3 is used for adjusting the atmospheric pressure in air circuit.

The cooling loop comprises an expansion water tank 4, a water pump 5, a water inlet pipe, a water outlet pipe and a water supplementing pipe, cooling liquid is introduced into the galvanic pile 1 under the action of the water pump 5 and flows back to a water inlet of the water pump 5 from the galvanic pile 1, and the expansion water tank 4 is used for supplementing the cooling liquid to the cooling loop; in this embodiment, the coolant is water. The water outlet of the water pump 5 is connected to the cooling liquid inlet of the galvanic pile 1 through the water outlet pipe, and the cooling liquid flowing out of the cooling liquid outlet of the galvanic pile 1 flows back to the water inlet of the water pump 5 through the water inlet pipe after being cooled. In this embodiment, the coolant liquid that 1 coolant outlet of galvanic pile flows can dispel the heat through the radiator earlier, and rethread inlet pipe flows the water inlet of return water pump 5, cools off galvanic pile 1 once more. The expansion tank 4 reduces the water pressure fluctuation of the fuel cell cooling cycle system caused by the expansion and contraction of the coolant in the form of accommodating the surplus coolant in the cooling circuit or supplementing the cooling circuit with the coolant, which is simply described as the expansion tank 4 in this embodiment. Therefore, the expansion tank 4 is connected to the inlet of the water pump 5 through the makeup pipe.

The pressure loop comprises an air pipe and a one-way valve 42, one end of the air pipe is connected to an air outlet of the electric pile 1, the other end of the air pipe is connected to the expansion water tank 4, and the one-way valve 42 is arranged between the air outlet of the electric pile 1 and the expansion water tank 4 and is used for conducting the air outlet to the expansion water tank 4 and blocking the expansion water tank 4 to the air outlet; specifically, the pressure upstream of the pressure regulating valve 3, i.e., the pressure of the air discharged from the stack 1, is generally about 2 atmospheres, and the pressure downstream of the pressure regulating valve 3, i.e., the atmosphere, so that one end of the gas pipe is connected to the exhaust pipe, and the connection between the gas pipe and the exhaust pipe is located upstream of the pressure regulating valve 3.

Furthermore, the pipeline between the air outlet of the pile 1 and the expansion water tank 4 is inclined upwards or vertically upwards, so that the pipeline is prevented from bending downwards and then upwards, and the increase of flow resistance caused by the accumulation of water at the cathode outlet of the pile in the pipeline is prevented. In this embodiment, the fuel cell cooling circulation system further includes a support structure for supporting the pipe between the air outlet of the stack 1 and the expansion tank 4, so that the pipe between the air outlet of the stack 1 and the expansion tank 4 is inclined upward or vertically upward.

As shown in fig. 2, the expansion tank 4 includes a tank 43 and a pressure cover 41, the water replenishing pipe is connected to the tank 43, the pressure cover 41 is provided with a pressure relief opening, the check valve 42 is integrated on the tank 43 of the expansion tank 4, specifically, the pressure cover 41 is arranged on the top of the tank 43, the check valve 42 is integrated on the side wall of the tank 43, and the position of the check valve 42 is higher than the highest liquid level in the tank 43 of the expansion tank 4, so that the cooling liquid in the expansion tank 4 is uniformly pressurized, and the cooling liquid in the expansion tank 4 is not stirred.

The invention idea of the application is as follows:

in order to ensure the pressure difference between the cooling side of the electric pile 1 and the anode and the cathode of the electric pile 1, a water pump 5 with a large lift needs to be arranged, and the relationship between the lift and the pressure of the water pump 5 is as follows:

wherein H represents the head of the water pump 5 in m; p₃The pressure of the water outlet of the water pump 5 is expressed in unit Pa; p₄The pressure at the water inlet of the water pump 5 is expressed in Pa; ρ represents the density of the coolant flowing in the cooling circuit in kg/m³(ii) a g represents the acceleration of gravity in m/s²；V₂The flow speed at the water outlet of the water pump 5 is shown in m/s; v₁The flow speed at the water inlet of the water pump is expressed in m/s; z₂The height of the water outlet of the water pump 5 is expressed in m; z₁The height of the water inlet of the water pump is expressed in m;

maintaining a cooling liquidFlow velocity V₁、V₂Height Z of water inlet and outlet₁、Z₂And outlet pressure P₃Under the condition of no change, the lift H and the water inlet pressure P of the water pump 5 can be found₄In inverse proportion:

therefore, if the pressure P at the water inlet of the water pump 5 is increased₄The required pump 5 head H will be reduced. Therefore, the inventor's idea is to increase the pressure P at the water inlet of the water pump 5₄。

The pressure P of the water inlet of the water pump 5 is not considered under the condition of pipeline pressure loss₄Equal to the pressure P in the expansion tank 4₀If a pressure increasing device is added in the expansion water tank 4 to increase the pressure of the expansion water tank 4, the pressure P at the water inlet of the water pump 5 can be increased₄However, the cost of adding a pressure boosting device is high, and the volume of the fuel cell system is increased.

After research and analysis, the inventor finds that the air compressed by the air compressor 2 has a certain pressure, and the compressed air still has a certain pressure after being discharged from the electric pile 1 and is higher than the pressure in the expansion water tank 4. If compressed air is introduced into the expansion tank 4 at the air inlet of the cell stack 1, as in the case of patent CN210668556U, the following disadvantages occur:

(1) after compressed air is introduced into the expansion water tank 4, a certain pressure is provided in the expansion water tank 4, and when the air compressor 2 stops operating, water and gas in the expansion water tank 4 can flow back into an air loop, so that the service life of a fuel cell is influenced; therefore, when the patent CN210668556U is implemented, the expansion tank 4 must be depressurized first and then the air compressor 2 is stopped, which is not only cumbersome to operate, but also can not prevent water and air in the expansion tank 4 from flowing backward into the air circuit when the pressure of the air circuit is smaller than the pressure of the expansion tank 4.

(2) The gas pressure at the outlet of the air compressor 2 and the inlet of the electric pile 1 often fluctuates, and the fluctuation can be directly transmitted to the expansion water tank 4, so that the pressure fluctuation also occurs in the cooling loop, and the water pressure temperature of the cooling loop is not facilitated; the patent CN210668556U has the pressure regulating valve on the air delivery pipe to avoid such pressure fluctuation, but this results in increase of cost and volume, which is not favorable for integrated arrangement of fuel cell.

(3) The air flow at the inlet of the electric pile 1 is positively correlated with the power of the electric pile 1, the flow of the air compressor 2 is represented as the pressure, in short, the higher the power of the electric pile 1 is, the larger the air pressure at the inlet of the electric pile 1 is, so that the pressure of the expansion water tank 4 is increased along with the increase of the power of the electric pile 1, but the pressure of the load of the expansion water tank 4 is limited, when the power of the electric pile 1 reaches a certain degree, the air pressure at the inlet of the electric pile 1 also reaches a certain magnitude, and when the pressure in the expansion water tank 4 is too large, the pressure cover 41 is triggered to release the pressure to release the air, so that the air pressure at the inlet of the electric pile 1 cannot be increased continuously due to the pressure release of the pressure cover 41 after reaching a certain degree, so that the power of the electric pile 1 cannot be increased continuously after reaching a certain degree. In patent CN210668556U, a pressure sensor, a pressure regulating valve, etc. are provided on the gas pipe, but this results in increase of cost and volume, which is not favorable for integrated arrangement of the fuel cell.

Therefore, if compressed air is introduced into the expansion tank 4 at the air inlet of the stack 1, although the lift of the water pump 5 is reduced, a new problem is caused.

After further research and analysis, the inventor finds that the compressed air is directly discharged out of the electric pile 1 after being introduced into the electric pile 1, namely the compressed air is discharged from an exhaust pipe at an air outlet of the electric pile 1 after reacting in the electric pile 1, and in order to ensure that an air circuit has a certain pressure, the exhaust pipe is provided with a pressure regulating valve 3, the pressure at the upstream of the pressure regulating valve 3, namely the pressure of the air discharged by the electric pile 1, is generally about 2 atmospheric pressures, and the pressure at the downstream of the pressure regulating valve 3, namely the atmospheric pressure.

After the research of the inventor, it is found that after the compressed air reacts in the electric pile 1, although the gas pressure at the air outlet of the electric pile 1 is lower than the gas pressure at the air inlet of the electric pile 1, the pressure at the air outlet is still higher than the pressure of the expansion water tank 4, so that the compressed air at the air inlet of the electric pile 1 can be introduced into the expansion water tank 4, and compared with the patent CN210668556U, the compressed air introduced into the air outlet of the electric pile 1 has the following advantages:

(1) the air compressed by the air compressor 2 tends to be stable after being discharged through the electric pile 1, basically no pressure fluctuation exists, and the pressure transmitted to the expansion water tank 4 also tends to be stable, so that the stability of a cooling loop is facilitated, and a pressure regulating part does not need to be arranged on an air conveying pipe.

(2) The flow resistance exists in the pile 1, when the pressure of the air compressor 2 rises continuously, the air inlet pressure of the pile 1 rises continuously, the air outlet pressure of the pile 1 also increases correspondingly, however, the flow resistance of the pile 1 also increases continuously along with the increase of the air loop pressure, so the pressure of the air outlet of the pile 1 is increased slowly, the pressure is adjusted by the flow resistance of the pile 1, and the pressure adjusting part does not need to be arranged on an air conveying pipe.

(3) When the power of the electric pile 1 rises continuously, even if the expansion water tank 4 releases pressure due to overlarge pressure, the pressure at the inlet of the electric pile 1 is hardly influenced, and the power of the electric pile 1 can be continuously increased by matching with the pressure regulating valve 3 on the exhaust pipe.

(4) This application has integrated check valve 42 on expansion tank 4, and check valve 42 makes air outlet to 4 directions of expansion tank switch on to make expansion tank 4 to air outlet direction block, effectively avoided the water and the gas in expansion tank 4 to flow backward.

This application has effectively reduced the needs of fuel cell system to the lift of water pump 5, can balance the pressure of cooling water side and air side, and the assurance that air side pressure and cooling circuit pressure can be fine is in reasonable within range to improve 1 life of galvanic pile.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.