CN116072919B

CN116072919B - Fuel cell thermal management system

Info

Publication number: CN116072919B
Application number: CN202310042352.2A
Authority: CN
Inventors: 郭跃新; 吴苗丰; 付苏明
Original assignee: Shenzhen Hynovation Technologies Co ltd
Current assignee: Shenzhen Hynovation Technologies Co ltd
Priority date: 2023-01-28
Filing date: 2023-01-28
Publication date: 2023-07-04
Anticipated expiration: 2043-01-28
Also published as: CN116072919A

Abstract

The invention discloses a fuel cell thermal management system, which comprises a heat exchanger, a first circulation loop and a second circulation loop, wherein the heat exchanger comprises a first channel and a second channel; the first circulation loop is communicated with two ends of the first channel and is connected in series with a liquid cold source; the second circulation loop is communicated with two ends of the second channel and comprises a water pump, a galvanic pile assembly and a first three-way valve which are sequentially connected in series, and a shunt port of the first three-way valve is communicated between the water pump and the second channel. The fuel cell heat management system provided by the invention realizes heat exchange and cooling of the electric pile assembly through the cooperation of the first circulation loop, the heat exchanger and the second circulation loop, and has high heat exchange efficiency and low noise through the heat exchange of liquid and liquid.

Description

Fuel cell thermal management system

Technical Field

The invention relates to the field of fuel cells, in particular to a fuel cell thermal management system.

Background

The proton exchange membrane fuel cell (Proton Exchange Membrane Fuel Cells, hereinafter abbreviated as PEMFC) is an electrochemical power generation device which takes hydrogen and oxygen as raw materials to carry out electrochemical reaction to generate water and simultaneously convert chemical energy into electric energy, and has the characteristics of cleanness, high efficiency, energy conservation, environmental protection, high energy conversion rate and the like. Temperature is one of the important factors affecting the performance of the fuel cell, and affects the gas transport characteristics of the PEMFC, the water content of the membrane, the catalytic characteristics of the catalytic layer, the output characteristics, and even the service life to various extents. In addition to generating electric energy during the operation of the PEMFC, about half of the energy is output in the form of heat energy, so that excessive heat must be timely discharged to maintain the stability of the operating temperature of the system. The cooling mode of the current thermal management system generally uses a radiator for liquid-wind heat exchange, and the radiator has relatively low heat exchange efficiency and high noise.

Disclosure of Invention

The invention mainly aims to provide a fuel cell thermal management system which is used for solving the problem that the traditional thermal management system is low in cooling heat exchange efficiency by using a radiator.

In order to achieve the above object, a fuel cell thermal management system according to the present invention includes a heat exchanger, a first circulation loop, and a second circulation loop, the heat exchanger including a first channel and a second channel; the first circulation loop is communicated with two ends of the first channel, and is connected in series with a liquid cold source; the second circulation loop is communicated with two ends of the second channel and comprises a water pump, a galvanic pile assembly and a first three-way valve which are sequentially connected in series, and a shunt opening of the first three-way valve is communicated between the water pump and the second channel;

the second circulation loop further comprises a coolant filter connected in series between the water pump and the pile assembly;

the fuel cell thermal management system further comprises a pressure stabilizing branch, wherein a resistance component and an expansion water tank are sequentially connected in series with the pressure stabilizing branch, the resistance component is communicated between the water pump and the cooling liquid filter, and the expansion water tank is communicated between the second channel and the water pump;

the number of the second circulation loops is multiple, the second circulation loops are arranged in parallel, and each second circulation loop is correspondingly provided with the voltage stabilizing branch.

Optionally, the first circulation loop further comprises a first control valve and a second control valve connected in series at two ends of the first channel, and the second circulation loop further comprises a third control valve and a fourth control valve connected in series at two ends of the second channel.

Optionally, the voltage stabilizing branch further comprises a deionizer, one end of the deionizer is communicated with the cooling liquid outlet of the galvanic pile assembly, and the other end of the deionizer is communicated between the resistance component and the expansion water tank.

Optionally, each of the second circulation circuits further includes an on-off valve connected in series between the second passage and the water pump.

Optionally, the electric pile assembly and the first three-way valve are connected in series to form electric pile heat exchange branches, the number of the electric pile heat exchange branches is multiple, and the electric pile heat exchange branches are arranged between the water pump and the second channel in parallel.

Optionally, a first stop valve and a second stop valve are arranged at two ends of the water pump.

Optionally, the second circulation loop further comprises a second three-way valve connected in series between the pile assembly and the first three-way valve, a split port of the second three-way valve is communicated between the second channel and the water pump through a connecting pipe, and a heater is arranged on the connecting pipe.

According to the technical scheme, the heat exchanger comprises a first channel and a second channel, the first circulation loop is communicated with two ends of the first channel, and the first circulation loop is connected with a liquid cold source in series, so that low-temperature liquid can flow in the first circulation loop and the first channel. The second circulation loop is communicated with the two ends of the second channel, and high-temperature liquid in the second circulation loop exchanges heat with low-temperature liquid in the first circulation loop through the heat exchanger, so that cooling liquid in the second circulation loop is cooled, heat exchange efficiency is high, and noise is low. The second circulation loop comprises a water pump, a pile assembly and a first three-way valve which are sequentially connected in series, wherein the water pump is used for providing power for cooling liquid circulation, and cooling liquid is pumped out of the second channel to enter the pile assembly, so that the pile assembly is subjected to heat exchange and cooling. The first three-way valve is communicated between the cooling liquid outlet of the electric pile assembly and the second channel, and the opening degree of the first three-way valve is adjusted to change the flow rate of the cooling liquid flowing through the second channel, so that the heat exchange amount of the heat exchanger is changed. The diversion port of the first three-way valve is communicated between the water pump and the second channel, and the low-temperature liquid in the second channel is mixed with the high-temperature liquid of the diversion port of the first three-way valve in temperature, so that the temperature requirement of the cooling liquid required by the electric pile assembly can be met. The fuel cell heat management system provided by the invention realizes heat exchange and cooling of the electric pile assembly through the cooperation of the first circulation loop, the heat exchanger and the second circulation loop, and has high heat exchange efficiency and low noise through the heat exchange of liquid and liquid.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a thermal management system for a fuel cell according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a fuel cell thermal management system according to another embodiment of the present invention.

Reference numerals illustrate:

the achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present invention are merely used to explain the relative positional relationship, movement, etc. between the components in a particular posture (as shown in the drawings), and if the particular posture is changed, the directional indicator is changed accordingly.

Furthermore, descriptions such as those referred to as "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying an order of magnitude of the indicated technical features in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless specifically stated and limited otherwise, the terms "connected," "affixed," and the like are to be construed broadly, and for example, "affixed" may be a fixed connection, a removable connection, or an integral body; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, the technical solutions of the embodiments of the present invention may be combined with each other, but it is necessary to be based on the fact that those skilled in the art can implement the technical solutions, and when the technical solutions are contradictory or cannot be implemented, the combination of the technical solutions should be considered as not existing, and not falling within the scope of protection claimed by the present invention.

The present invention provides a fuel cell thermal management system 100.

In one embodiment, as shown in fig. 1-2, a fuel cell thermal management system 100 includes a heat exchanger 10, a first circulation loop 20, and a second circulation loop 30, the heat exchanger 10 including a first channel and a second channel; the first circulation loop 20 is communicated with two ends of the first channel, and the first circulation loop 20 is connected in series with a liquid cold source 21; the second circulation loop 30 is connected to two ends of the second channel, the second circulation loop 30 includes a water pump 31, a galvanic pile assembly 32 and a first three-way valve 33 connected in series in sequence, and a split-flow port of the first three-way valve 33 is connected between the water pump 31 and the second channel.

The heat exchanger 10 in this embodiment is a plate heat exchanger 10, and the cooling mode using the plate heat exchanger 10 is lower in cost, noiseless, small in size, and high in heat exchange efficiency compared with a radiator, and is more advantageous than a radiator in the field of distributed power generation or marine applications. The plate heat exchanger 10 is configured to reduce the temperature of the high-temperature liquid to a desired temperature by passing the high-temperature liquid through one side and passing the low-temperature liquid provided by the liquid cooling source 21 through the other side, and by exchanging heat between the low-temperature liquid and the high-temperature liquid. If the fuel cell system is applied to a ship, the liquid cold source 21 may be sea water or low-temperature fresh water provided on the ship; if the fuel cell system is applied to distributed power generation or cogeneration, the liquid cold source 21 may be low temperature water provided by a cooling tower; if the distributed power generation equipment is close to a lake or the sea, the liquid cold source 21 can use lake water or sea water without a cooling tower, and the cost can be greatly reduced by adopting local materials.

The heat exchanger 10 includes a first channel and a second channel, the first circulation loop 20 is connected to two ends of the first channel, and the first circulation loop 20 is connected in series with a liquid cooling source 21, so that the first circulation loop 20 and the first channel can circulate low-temperature liquid. The second circulation loop 30 is connected to two ends of the second channel, and the high-temperature liquid in the second circulation loop 30 exchanges heat with the low-temperature liquid in the first circulation loop 20 through the heat exchanger 10, so that the cooling liquid in the second circulation loop 30 is cooled, the heat exchange efficiency is high, and the noise is low. The second circulation loop 30 comprises a water pump 31, a pile assembly 32 and a first three-way valve 33 which are sequentially connected in series, wherein the water pump 31 is used for providing power for cooling liquid circulation, and cooling liquid is pumped out of the second channel to enter the pile assembly 32, so that the pile assembly 32 is subjected to heat exchange and cooling. The first three-way valve 33 is communicated between the coolant outlet of the stack assembly 32 and the second passage, and the flow rate of the coolant flowing through the second passage is changed by adjusting the opening of the first three-way valve 33, thereby changing the heat exchange amount of the heat exchanger 10. The diversion port of the first three-way valve 33 is communicated between the water pump 31 and the second channel, and the low-temperature liquid in the second channel is mixed with the high-temperature liquid of the diversion port of the first three-way valve 33 in temperature, so that the two are combined to meet the temperature requirement of the cooling liquid required by the galvanic pile assembly 32.

The fuel cell thermal management system 100 in the invention realizes heat exchange and cooling of the electric pile assembly 32 through the cooperation of the first circulation loop 20, the heat exchanger 10 and the second circulation loop 30, and has high heat exchange efficiency and low noise through the heat exchange of liquid and liquid.

The cooling liquid inlet is provided with a water temperature sensor and a water pressure sensor, the cooling liquid outlet is provided with a water temperature sensor, the detection of the water temperature and the water pressure of the cooling liquid is realized, and the heat exchange efficiency of the heat exchanger 10 is conveniently controlled according to the detection result of the water temperature and the water pressure.

In an embodiment, referring to fig. 1 and 2 in combination, the first circulation loop 20 further includes a first control valve 11 and a second control valve 12 connected in series at two ends of the first channel, and the second circulation loop 30 further includes a third control valve 13 and a fourth control valve 14 connected in series at two ends of the second channel.

By arranging the first control valve 11, the second control valve 12, the third control valve 13 and the fourth control valve 14, the heat exchanger 10 is convenient to maintain and replace after being worn, and the heat exchanger 10 is more convenient to use.

In an embodiment, referring to fig. 1 and 2 in combination, the second circulation loop 30 further includes a coolant filter 34 connected in series between the water pump 31 and the stack assembly 32.

The coolant filter 34 is used to filter impurities in the coolant, prevent the impurities from entering the stack assembly 32 and damaging the stack assembly 32, prolong the service life of the stack assembly 32, and improve the reliability of the fuel cell thermal management system 100.

In an embodiment, referring to fig. 1 and 2 in combination, the fuel cell thermal management system 100 further includes a pressure stabilizing branch 35, the pressure stabilizing branch 35 is sequentially connected in series with a resistance component 351 and an expansion water tank 352, the resistance component 351 is connected between the water pump 31 and the coolant filter 34, and the expansion water tank 352 is connected between the second channel and the water pump 31.

The expansion tank 352 is primarily used to provide fluid expansion space, water make-up, pressure stabilization, venting, etc. for the second circuit 30. The resistance element 351 is used to increase the resistance of the pressure stabilizing branch 35, thereby reducing the flow of the pressure stabilizing branch 35, and because the pressure stabilizing branch 35 is used for exhausting and cannot be branched too much, the resistance element 351 needs to be added to reduce the flow. The reliability and stability of the fuel cell thermal management system 100 system is improved by providing a pressure stabilizing branch 35 to vent.

The expansion water tank 352 is internally provided with a liquid level sensor, when the liquid level of the expansion water tank 352 is normal, the liquid level sensor is in a foot-off state, and the FCU controller does not collect high level, so that no fault is reported. When the liquid level of the expansion water tank 352 is low, the liquid level sensor and the foot are in a conducting state, the FCU controller continuously collects high level and is effective for E seconds, and the fault of low liquid level of the expansion water tank 352 is reported, so that only a warning and an instrument prompt are made.

In one embodiment, referring to fig. 1 and 2 in combination, the voltage stabilizing branch 35 further includes a deionizer 353, wherein one end of the deionizer 353 is connected to the cooling liquid outlet of the stack assembly 32, and the other end of the deionizer 353 is connected between the resistance member 351 and the expansion tank 352.

The deionizer 353 reduces the conductivity of the coolant in the second circulation loop 30, preventing the coolant from having too high a conductivity, and thus reducing the insulation resistance of the fuel cell thermal management system 100. And, the deionizer 353 is disposed in the voltage stabilizing branch 35, so that the cooling efficiency of the stack heat exchanging branch 37 is prevented from being reduced due to the too large flow resistance of the deionizer 353.

In an embodiment, referring to fig. 1, the number of the second circulation loops 30 is plural, the plural second circulation loops 30 are arranged in parallel, and each second circulation loop 30 is correspondingly provided with a voltage stabilizing branch 35.

At present, the power of a single PEMFC system is still insufficient for distributed power generation, cogeneration or application on a ship, and in this embodiment, the number of the second circulation loops 30 is multiple, and the multiple second circulation loops 30 are arranged in parallel to increase the power of power generation. Each second circulation loop 30 is correspondingly provided with a pressure stabilizing branch 35, and provides a liquid expansion space, water supplementing, pressure stabilizing, air exhausting and the like for the second circulation loop 30. And a plurality of second circulation loops 30 share one heat exchanger 10, so that the structural design is compact, and the space utilization rate is improved.

In an embodiment, referring to fig. 1 in combination, each of the second circulation circuits 30 further includes an on-off valve 36 connected in series between the second channel and the water pump 31.

Whether the corresponding second circulation loop 30 is filled with the cooling liquid or not is conveniently controlled by arranging the switch valve 36, so that the structural design of the fuel cell thermal management system 100 is more reasonable and the use is more convenient.

In an embodiment, referring to fig. 2 in combination, the stack assembly 32 and the first three-way valve 33 are connected in series to form a stack heat exchange branch 37, the number of the stack heat exchange branches 37 is plural, and the plurality of stack heat exchange branches 37 are arranged in parallel between the water pump 31 and the second channel.

The stack heat exchanging branch 37 includes a stack assembly 32 and a first three-way valve 33 connected in series in sequence, and the number of the stack heat exchanging branch 37 is plural to increase the generated power. In addition, the plurality of electric pile heat exchange branches 37 are arranged between the water pump 31 and the second channel in parallel, namely, the plurality of electric pile heat exchange branches 37 share the heat exchanger 10, the water pump 31 and the expansion water tank 352, so that the structure of the fuel cell heat management system 100 is more compact, the space utilization rate is further improved, and the fuel cell heat management system is particularly suitable for ships with limited areas.

Each stack heat exchange branch 37 further comprises a switch valve 36 connected in series between the water pump 31 and the coolant filter 34, and whether the corresponding stack heat exchange branch 37 is filled with coolant is conveniently controlled by setting the switch valve 36, so that the structural design of the fuel cell heat management system 100 is more reasonable and the use is more convenient.

In an embodiment, referring to fig. 2, a first stop valve 311 and a second stop valve 312 are disposed at two ends of the water pump 31.

Through setting up first stop valve 311 and second stop valve 312 at the both ends of water pump 31, make things convenient for maintenance and change after the wearing and tearing of water pump 31 for water pump 31's use is more convenient.

In an embodiment, referring to fig. 1 and 2 in combination, the second circulation loop 30 further includes a second three-way valve 38 connected in series between the stack assembly 32 and the first three-way valve 33, and a split port of the second three-way valve 38 is connected between the second channel and the water pump 31 through a connecting pipe 39, and a heater 391 is disposed on the connecting pipe 39.

The second three-way valve 38 is connected in series between the pile assembly 32 and the first three-way valve 33, the heater 391 is a PTC heater 391, which is composed of a PTC ceramic heating element and an aluminum tube, and the PTC heater 391 has the advantages of small thermal resistance and high heat exchange efficiency, and is an automatic constant temperature and electricity-saving electric heater 391. The outstanding characteristics are that the surface of the electrothermal tube heater 391 is not reddish under any application condition in terms of safety performance. The first three-way valve 33, the second three-way valve 38, the heater 391 and the heat exchanger 10 cooperate to regulate the temperature of the cooling liquid in the stack heat exchange branch 37.

Specific control strategies: the fuel cell thermal management system 100 is in a self-test state, and the water pump 31 is set at a fixed rotation speed X1rpm; the fuel cell thermal management system 100 enters a start-up state, and the water pump 31 sets a fixed rotation speed X2rpm; the fuel cell thermal management system 100 is in an operating state or a shutdown load-reducing state, the water pump 31 is controlled by a PID closed loop, and under different power working conditions, the PID algorithm operation is performed on the deviation value according to the deviation between the actual temperature difference between the cooling liquid inlet and the cooling liquid outlet (obtained by the difference between the detection values of the water temperature sensor of the inlet stack and the water temperature sensor of the outlet stack) and the target temperature difference, so that the rotating speed of the water pump 31 is automatically regulated to meet the target temperature difference requirement. The fuel cell thermal management system 100 is in a shutdown state, and the water pump 31 is set at a fixed rotation speed X3rpm.

When the fuel cell thermal management system 100 is not open, the default state opening degrees of the first three-way valve 33 and the second three-way valve 38 are both 0. When the fuel cell thermal management system 100 is powered on and in a self-checking state, the opening degree of the first three-way valve 33 and the second three-way valve 38 is adjusted from the default opening degree 0 to the opening degree 50, after 10S operation, whether a cold start program is entered is judged according to the detection result of the water temperature sensor for discharging the stack, if the temperature is less than or equal to Y1 ℃, the cold start program is entered, otherwise, the cold start program is not entered, and after the judgment, the opening degrees of the first three-way valve 33 and the second three-way valve 38 are adjusted to 0.

In the normal operation state, the second three-way valve 38 enters a PID closed loop automatic control opening program, namely under different power working conditions, PID operation is carried out according to the deviation between the target temperature of the cooling liquid inlet and the actual temperature and the deviation between the target temperature of the cooling liquid outlet and the actual temperature, the target opening of the second three-way valve 38 is output, when the current is less than or equal to Z1A, the target opening of the PID control output is executed, when the current is more than or equal to Z2A, the target opening of the second three-way valve 38 is always kept at 95, when the current is reduced from more than Z2A to less than or equal to Z1A, the target opening is changed to be based on the PID control output value, and if the initial current at the starting is just between Z1A and Z2A, the PID control output value is used as the target opening. The second three-way valve 38 is automatically controlled to a target angle by a PID control algorithm using the target opening degree and the actual opening degree.

The first three-way valve 33 keeps 0 opening all the time when the temperature of the cooling liquid inlet is less than or equal to A1 ℃; when the temperature of the cooling liquid inlet rises to A1 ℃, the first three-way valve 33 is slowly opened to B1 for 30S, then is slowly opened to B2 for 30S (the purpose is to open the electric pile heat exchange branch 37 for the first time, the first three-way valve 33 is required to be slowly opened to ensure that the instantaneous fluctuation of the temperature of the cooling liquid inlet does not exceed C1 ℃); thereafter, under different power conditions, the opening degree of the first three-way valve 33 is adjusted through a PID algorithm to realize temperature control by using the deviation of the target temperature and the actual temperature of the coolant inlet.

When the coolant inlet temperature is lower than D1 ℃, the heater 391 is started (full range start), when the temperature is heated to D1 ℃, the heater 391 is downshifted to 2 th gear heating, and when the temperature is heated to D2 ℃, the heater 391 is turned off.

The foregoing description of the preferred embodiments of the present invention should not be construed as limiting the scope of the invention, but rather utilizing equivalent structural changes made in the present invention description and drawings or directly/indirectly applied to other related technical fields are included in the scope of the present invention.

Claims

1. A fuel cell thermal management system, the fuel cell thermal management system comprising:

a heat exchanger comprising a first channel and a second channel;

the first circulating loop is communicated with two ends of the first channel and is connected with a liquid cold source in series;

the second circulation loop is communicated with two ends of the second channel and comprises a water pump, a galvanic pile assembly and a first three-way valve which are sequentially connected in series, and a shunt opening of the first three-way valve is communicated between the water pump and the second channel;

2. The fuel cell thermal management system of claim 1 wherein the first circulation loop further comprises a first control valve and a second control valve in series across the first channel, the second circulation loop further comprising a third control valve and a fourth control valve in series across the second channel.

3. The fuel cell thermal management system of claim 1 wherein the pressure stabilizing branch further comprises a deionizer having one end in communication with the cooling fluid outlet of the stack assembly and the other end in communication between the resistance element and the expansion tank.

4. The fuel cell thermal management system according to claim 1 wherein each of said second circulation circuits further comprises an on-off valve connected in series between said second passage and said water pump.

5. The fuel cell thermal management system according to any one of claims 1 to 4, wherein the stack assembly and the first three-way valve are connected in series to form a stack heat exchange branch, the number of the stack heat exchange branches is plural, and the plural stack heat exchange branches are arranged in parallel between the water pump and the second passage.

6. The fuel cell thermal management system according to claim 5, wherein both ends of the water pump are provided with a first shut-off valve and a second shut-off valve.

7. The fuel cell thermal management system according to any one of claims 1 to 4 wherein the second circulation circuit further comprises a second three-way valve connected in series between the stack assembly and the first three-way valve, and a split port of the second three-way valve is connected between the second passage and the water pump through a connection pipe, the connection pipe being provided with a heater.