Electric pile heat dissipation system for hydrogen energy automobile

Abstract

The invention discloses an electric pile heat dissipation system for a hydrogen energy automobile, which comprises a heat dissipation plate arranged on the side wall of an electric pile, and the heat dissipation plate comprises a base and a cover plate which are mutually covered to form a flow guide channel; the flow guide channel comprises a main flow guide channel and an auxiliary flow guide channel, and the main flow guide channel and the auxiliary flow guide channel are both connected with a liquid inlet pipe; and the tail ends of the main flow guide channel and the auxiliary flow guide channel converge and are connected with a liquid outlet pipe. The galvanic pile heat dissipation system provided by the invention has excellent heat dissipation performance.

Description

Technical Field

[0001] The present invention relates to the technical field of heat dissipation of fuel cells, and in particular to a heat dissipation system of fuel cells for hydrogen energy vehicles. Background Art

[0002] The current mainstream hydrogen fuel cell heat dissipation technology is dominated by liquid cooling systems, which remove the heat generated by the stack through the circulation of coolant. For example, Quanchai Power uses "water + ethylene glycol" liquid cooling in 15kW and 40kW hydrogen fuel cell stacks, using the high specific heat capacity characteristics of the coolant to achieve thermal management. Such systems usually include cooling water circulation channels, radiators, water pumps and other components; or combined with wastewater cooling channels and spray devices, the heat dissipation efficiency is improved through multi-channel design; in addition, the heat dissipation structure can be optimized, such as introducing dual heat sinks or multi-stage heat dissipation channels, to meet the needs of different temperature conditions.

[0003] Since the heat load of a hydrogen fuel cell stack is significantly higher than that of a traditional internal combustion engine (about 50%-60% of the heat needs to be dissipated, while an internal combustion engine only needs 20%), and the operating temperature range of the stack is narrow (usually maintained at 60-80°C), the existing liquid cooling system is prone to heat dissipation lag when the stack is running at high load, resulting in local overheating, affecting the performance and life of the stack. At the same time, it is difficult for traditional cooling systems to dynamically adjust the heat dissipation intensity according to the real-time power changes of the stack. For example, it may be over-cooled during low-temperature startup or low-load operation, resulting in energy waste.

[0004] Therefore, there is an urgent need to develop a fuel cell stack cooling system with excellent heat dissipation performance. Summary of the invention

[0005] Based on the technical problems existing in the background technology, the present invention proposes a fuel cell heat dissipation system for a hydrogen energy vehicle, which has excellent heat dissipation performance.

[0006] The present invention proposes a heat dissipation system for a fuel cell stack of a hydrogen energy vehicle, comprising:

[0007] A heat sink disposed on the side wall of the stack, the heat sink comprising a base and a cover plate that overlap each other and form a flow guide channel;

[0008] The flow guiding channel comprises a main flow guiding channel and a secondary flow guiding channel, and both the main flow guiding channel and the secondary flow guiding channel are connected with a liquid inlet pipe;

[0009] The main flow channel and the auxiliary flow channel converge at their ends and are connected with a liquid outlet pipe.

[0010] Preferably, the main flow channel is connected to a main liquid inlet pipe, and the auxiliary flow channels are distributed on both sides of the main flow channel and are respectively connected to a first auxiliary liquid inlet pipe and a second auxiliary liquid outlet pipe.

[0011] Preferably, the base is provided with a first guide plate, a second guide plate and a third guide plate, the second guide plate is arranged between the first guide plate and the third guide plate, the first guide plate forms a main flow channel, the third guide plate forms a secondary flow channel, and the second guide plate is used to guide the liquid to the confluence of the main flow channel and the secondary flow channel at the end.

[0012] Preferably, ribs distributed in an array are provided between adjacent first guide plates and adjacent third guide plates.

[0013] Preferably, the first guide plate, the second guide plate, the third guide plate and the side walls of the ribs are all coated with phase change microcapsule materials.

[0014] Preferably, the method steps for preparing the phase change microcapsule material are as follows:

[0015] S1: paraffin wax, cellulose grafted polyethylene glycol, chitosan grafted oleic acid and an emulsifier are mixed and emulsified to obtain an emulsion;

[0016] S2: Evenly mix tetraethyl orthosilicate, anhydrous ethanol and hydrochloric acid to obtain a mixed solution;

[0017] S3: Add S1 emulsion dropwise into the mixed solution, stir and react to obtain phase change microcapsule material.

[0018] Preferably, the emulsifier is Span80, and the mass ratio of paraffin, cellulose grafted polyethylene glycol, chitosan grafted oleic acid and emulsifier is 1:0.1-0.5:0.1-0.5:0.01-0.03.

[0019] Preferably, the mass ratio of tetraethyl orthosilicate to paraffin is 1:5-10, and the volume ratio of the tetraethyl orthosilicate to the anhydrous ethanol is 1:3-5.

[0020] Preferably, the reaction temperature in S3 is 40-50°C and the reaction time is 3-6h.

[0021] Preferably, a piezoelectric ceramic pulsation generator is also provided at the confluence of the main flow channel and the secondary flow channel.

[0022] Beneficial technical effects of the present invention:

[0023] (1) The guide channel in the heat dissipation plate of the present invention includes a main guide channel and a secondary guide channel. The coolant flow rate of the main guide channel and the secondary guide channel can be adjusted according to the heat distribution of the battery stack to achieve sufficient heat dissipation of the battery stack and avoid the problem of uneven heat dissipation. By arranging ribs in the main guide channel and the secondary guide channel, not only the effective heat transfer area is increased, but also the fluid can be guided to be evenly distributed to avoid excessively high or low local flow rates.

[0024] (2) The first guide plate, the second guide plate, the third guide plate and the side walls of the ribs of the present invention are all coated with phase change microcapsule materials. Through the design of the phase change microcapsule materials, the heat conduction between the coolant and the phase change microcapsule materials is further improved, and the heat dissipation effect of the heat sink on the battery stack is improved. In addition, the cellulose grafted polyethylene glycol and chitosan grafted oleic acid in the phase change microcapsule materials of the present invention have a synergistic promoting effect in improving the heat dissipation effect.

[0025] (3) The present invention can generate high-frequency pressure fluctuations by arranging a piezoelectric ceramic pulsation generator at the confluence of the main flow channel and the secondary flow channel, causing the coolant fluid to oscillate periodically, destroying the stability of the boundary layer, enhancing the turbulence effect, and thus improving the heat transfer coefficient; when the pulsating pressure wave propagates in the fluid, it will induce eddies and secondary flows, promote the mixing of the coolant in the channel, and avoid excessive local temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of the heat dissipation plate proposed by the present invention;

[0027] Figure 2 This is a schematic structural diagram of the base proposed by the present invention.

[0028] In the figure: 1-base, 11-main liquid inlet pipe, 12-first auxiliary liquid inlet pipe, 13-second auxiliary liquid outlet pipe, 14-liquid outlet pipe, 15-first guide plate, 16-second guide plate, 17-third guide plate, 18-rib plate, 2-cover plate. DETAILED DESCRIPTION

[0029] The present invention will be further explained below in conjunction with specific embodiments.

[0030] Reference Figure 1-2 The present invention proposes a heat dissipation system for a fuel cell stack of a hydrogen energy vehicle, comprising:

[0031] The heat sink is arranged on the side wall of the stack, and the heat sink includes a base 1 and a cover plate 2 that cover each other and form a flow guide channel; the flow guide channel includes a main flow guide channel and a secondary flow guide channel, and both the main flow guide channel and the secondary flow guide channel are connected to a liquid inlet pipe; the main flow guide channel and the secondary flow guide channel converge at the end and are connected to a liquid outlet pipe. The liquid outlet pipe and the liquid inlet pipe can be connected to a liquid storage tank, and the coolant can be circulated and transported through a conveying device (such as a pump, etc.), and a solenoid valve is provided on the liquid inlet pipe to control the flow.

[0032] The guide channel in the heat dissipation plate of the present invention includes a main guide channel and a secondary guide channel. The coolant flow rate of the main guide channel and the secondary guide channel can be adjusted according to the heat distribution of the battery stack to achieve sufficient heat dissipation of the battery stack and avoid the problem of uneven heat dissipation. By arranging ribs in the main guide channel and the secondary guide channel, not only the effective heat transfer area is increased, but also the fluid can be guided to be evenly distributed to avoid excessively high or low local flow rates.

[0033] In order to achieve intelligent control of heat dissipation, temperature sensors are provided in the areas covered by the main flow channel and the auxiliary flow channel. The temperature sensors are connected to the control board. The control board adjusts the flow of the main flow channel and the auxiliary flow channel according to the temperature distribution of the battery stack fed back by the temperature sensor.

[0034] In this embodiment, the main flow channel is connected to a main liquid inlet pipe 11, and the auxiliary flow channels are distributed on both sides of the main flow channel and are respectively connected to a first auxiliary liquid inlet pipe 12 and a second auxiliary liquid outlet pipe 13.

[0035] The base 1 is provided with a first guide plate 15, a second guide plate 16 and a third guide plate 17. The second guide plate 16 is arranged between the first guide plate 15 and the third guide plate 17. The first guide plate 15 forms a main flow channel, the third guide plate 17 forms a secondary flow channel, and the second guide plate 16 is used to guide the liquid to the confluence of the main flow channel and the secondary flow channel at the end.

[0036] In another embodiment of the present invention, array-distributed ribs 18 are provided between adjacent first guide plates 15 and adjacent third guide plates 17. The design of the ribs not only increases the effective heat transfer area, but also guides the fluid to be evenly distributed to avoid excessively high or low local flow rates. Figure 2 For example, the ribs are inclined from the liquid inlet direction to the liquid outlet direction, and the inclination angle can be set between 30-60 degrees.

[0037] In another embodiment of the present invention, the first guide plate 15, the second guide plate 16, the third guide plate 17 and the side walls of the rib plate 18 are coated with phase change microcapsule materials. The design of the phase change microcapsule material can achieve heat conduction between the coolant and the phase change microcapsule material, thereby improving the heat dissipation effect of the heat sink on the battery stack.

[0038] In another embodiment of the present invention, a piezoelectric ceramic pulsation generator is further provided at the confluence of the end of the main flow channel and the secondary flow channel. The piezoelectric ceramic pulsation generator is electrically connected to the control board, and the piezoelectric ceramic pulsation generator can generate high-frequency pressure fluctuations, so that the coolant fluid produces periodic oscillations, destroys the stability of the boundary layer, enhances the turbulence effect, and thus improves the heat transfer coefficient; when the pulsating pressure wave propagates in the fluid, it will induce eddy currents and secondary flows, promote the mixing of the coolant in the channel, and avoid excessive local temperature.

[0039] Example 1

[0040] Paraffin, cellulose grafted polyethylene glycol, chitosan grafted oleic acid and Span80 are mixed and emulsified to obtain an emulsion; tetraethyl orthosilicate, anhydrous ethanol and hydrochloric acid are evenly mixed to obtain a mixed solution; S1 emulsion is added dropwise to the mixed solution, and the mixture is stirred and reacted at 45° C. for 4 hours to obtain phase change microcapsule material 1.

[0041] The mass ratio of paraffin, cellulose grafted polyethylene glycol, chitosan grafted oleic acid and Span80 is 1:0.3:0.3:0.02; the mass ratio of tetraethyl orthosilicate and paraffin is 1:8, and the volume ratio of tetraethyl orthosilicate and anhydrous ethanol is 1:4.

[0042] Example 2

[0043] Paraffin, cellulose grafted polyethylene glycol, chitosan grafted oleic acid and Span80 are mixed and emulsified to obtain an emulsion; tetraethyl orthosilicate, anhydrous ethanol and hydrochloric acid are evenly mixed to obtain a mixed solution; S1 emulsion is added dropwise to the mixed solution, and the mixture is stirred and reacted at 40°C for 6 hours to obtain phase change microcapsule material 2.

[0044] The mass ratio of paraffin, cellulose grafted polyethylene glycol, chitosan grafted oleic acid and Span80 is 1:0.1:0.1:0.01; the mass ratio of tetraethyl orthosilicate and paraffin is 1:5, and the volume ratio of tetraethyl orthosilicate and anhydrous ethanol is 1:3.

[0045] Example 3

[0046] Paraffin, cellulose grafted polyethylene glycol, chitosan grafted oleic acid and Span80 are mixed and emulsified to obtain an emulsion; tetraethyl orthosilicate, anhydrous ethanol and hydrochloric acid are evenly mixed to obtain a mixed solution; S1 emulsion is added dropwise to the mixed solution, and the mixture is stirred and reacted at 50°C for 3 hours to obtain phase change microcapsule material 3.

[0047] The mass ratio of paraffin, cellulose grafted polyethylene glycol, chitosan grafted oleic acid and Span80 is 1:0.5:0.5:0.03; the mass ratio of tetraethyl orthosilicate and paraffin is 1:10, and the volume ratio of tetraethyl orthosilicate and anhydrous ethanol is 1:5.

[0048] Comparative Example 1

[0049] Paraffin, cellulose grafted polyethylene glycol, chitosan grafted oleic acid and Span80 are mixed and emulsified to obtain an emulsion; tetraethyl orthosilicate, anhydrous ethanol and hydrochloric acid are evenly mixed to obtain a mixed solution; S1 emulsion is added dropwise to the mixed solution, and the mixture is stirred and reacted at 45°C for 4 hours to obtain phase change microcapsule material 4.

[0050] The mass ratio of paraffin, cellulose-grafted polyethylene glycol and Span80 is 1:0.6:0.02; the mass ratio of tetraethyl orthosilicate and paraffin is 1:8, and the volume ratio of tetraethyl orthosilicate and anhydrous ethanol is 1:4.

[0051] Comparative Example 2

[0052] Paraffin, cellulose grafted polyethylene glycol, chitosan grafted oleic acid and Span80 are mixed and emulsified to obtain an emulsion; tetraethyl orthosilicate, anhydrous ethanol and hydrochloric acid are evenly mixed to obtain a mixed solution; S1 emulsion is added dropwise to the mixed solution, and the mixture is stirred and reacted at 45°C for 4 hours to obtain phase change microcapsule material 5.

[0053] The mass ratio of paraffin, chitosan grafted oleic acid and Span80 is 1:0.6:0.02; the mass ratio of tetraethyl orthosilicate and paraffin is 1:8, and the volume ratio of tetraethyl orthosilicate and anhydrous ethanol is 1:4.

[0054] The heat dissipation effect of the heat sink prepared by the phase change microcapsule material of Examples 1-3 and Comparative Examples 1-2 was measured, and the measuring method was as follows: the stack was operated in the same manner, the heat sink was set on the side wall of the stack, and then a coolant was circulated through the heat sink to dissipate the heat of the stack, and the surface temperature of the stack was measured after a period of time. The test results are shown in Table 1.

[0055] Table 1 Heat dissipation test results

[0056] Group Surface temperature(℃) Example 1 43 Example 2 46 Example 3 44 Comparative Example 1 55 Comparative Example 2 57

[0057] It can be seen from the test results in Table 1 that the present invention further improves the heat conduction between the coolant and the phase change microcapsule material through the design of the phase change microcapsule material, improves the heat dissipation effect of the heat sink on the battery stack, and the cellulose grafted polyethylene glycol and chitosan grafted oleic acid in the phase change microcapsule material of the present invention have a synergistic promoting effect in improving the heat dissipation effect.

[0058] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application. The scope of the present application is defined by the appended claims and their equivalents, and all shall be included in the scope of protection of the present application.

Claims

1. A heat dissipation system for a hydrogen energy vehicle, characterized in that: include: A heat dissipation plate arranged on a side wall of the battery stack, the heat dissipation plate comprising a base (1) and a cover plate (2) which overlap each other and form a flow guide channel; The flow guiding channel comprises a main flow guiding channel and a secondary flow guiding channel, and both the main flow guiding channel and the secondary flow guiding channel are connected with a liquid inlet pipe; The main flow channel and the auxiliary flow channel converge at their ends and are connected with a liquid outlet pipe.

2. A heat dissipation system for a fuel cell stack of a hydrogen energy vehicle according to claim 1, characterized in that: The main flow channel is connected to a main liquid inlet pipe (11), and the auxiliary flow channels are distributed on both sides of the main flow channel and are respectively connected to a first auxiliary liquid inlet pipe (12) and a second auxiliary liquid outlet pipe (13).

3. The heat dissipation system for a fuel cell stack of a hydrogen energy vehicle according to claim 1, characterized in that: The base (1) is provided with a first guide plate (15), a second guide plate (16) and a third guide plate (17); the second guide plate (16) is arranged between the first guide plate (15) and the third guide plate (17); the first guide plate (15) forms a main guide channel; the third guide plate (17) forms a secondary guide channel; and the second guide plate (16) is used to guide liquid to a confluence point at the end of the main guide channel and the secondary guide channel.

4. The stack cooling system for a hydrogen energy vehicle according to claim 3 is characterized in that: Ribs (18) distributed in an array are provided between adjacent first guide plates (15) and adjacent third guide plates (17).

5. The heat dissipation system for a fuel cell stack of a hydrogen energy vehicle according to claim 4, characterized in that: The side walls of the first guide plate (15), the second guide plate (16), the third guide plate (17) and the rib plate (18) are all coated with phase change microcapsule material.

6. A heat dissipation system for a fuel cell stack of a hydrogen energy vehicle according to claim 5, characterized in that: The method steps for preparing the phase change microcapsule material are as follows: S1: paraffin wax, cellulose grafted polyethylene glycol, chitosan grafted oleic acid and an emulsifier are mixed and emulsified to obtain an emulsion; S2: Evenly mix tetraethyl orthosilicate, anhydrous ethanol and hydrochloric acid to obtain a mixed solution; S3: Add S1 emulsion dropwise into the mixed solution, stir and react to obtain phase change microcapsule material.

7. A heat dissipation system for a fuel cell stack of a hydrogen energy vehicle according to claim 6, characterized in that: The emulsifier is Span80, and the mass ratio of paraffin, cellulose grafted polyethylene glycol, chitosan grafted oleic acid and emulsifier is 1:0.1-0.5:0.1-0.5:0.01-0.

03.

8. The heat dissipation system for a fuel cell stack of a hydrogen energy vehicle according to claim 6, characterized in that: The mass ratio of ethyl orthosilicate to paraffin is 1:5-10, and the volume ratio of ethyl orthosilicate to anhydrous ethanol is 1:3-5.

9. The heat dissipation system for a fuel cell stack of a hydrogen energy vehicle according to claim 6, characterized in that: In S3, the reaction temperature is 40-50°C and the reaction time is 3-6h.

10. The stack cooling system for a hydrogen energy vehicle according to claim 1, characterized in that: A piezoelectric ceramic pulsation generator is also provided at the confluence point of the main flow channel and the auxiliary flow channel at the end.

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