Multifunctional heat exchange device and flow battery system

Abstract

The invention relates to a multifunctional heat exchange device and a flow battery system. The multifunctional heat exchange device comprises a multifunctional heat exchange device body, a mosquito-repellent incense type coil pipe, a heat exchange working medium pipeline inlet and a heat exchange working medium pipeline outlet, the mosquito-repellent incense type coil pipe comprises a positive coil pipe and a negative coil pipe, and the positive coil pipe and the negative coil pipe are spirally wound to form the mosquito-repellent incense type coil pipe. The flow channel layout in the heat exchange device is combined with the coil pipe, so that the heat exchange device has the effects of reducing bypass current and exchanging heat. The coil pipe in the heat exchange device is of a mosquito-repellent incense type structure, and the structure greatly reduces resistance drop caused by an elbow. Therefore, the bypass current and the resistance drop of the system can be reduced, the efficiency performance of the battery is improved, the compact design of the system can be realized, and the occupied space of the flow battery system is reduced.

Description

Technical Field

[0001] This invention relates to the field of flow battery technology, and more specifically, to a multifunctional heat exchange device and a flow battery system. Background Technology

[0002] A flow battery is a secondary battery technology in which the active materials exist in an electrolyte solution. Flow batteries achieve the interconversion of electrical energy and chemical energy through reversible electrochemical redox reactions involving the active materials in the positive and negative electrolytes.

[0003] In actual operation, a single flow battery cannot meet the voltage requirements for energy storage. To improve the DC voltage of the battery system, a certain number of single cells need to be connected in series to form a stack module, and multiple stack modules are connected in series and parallel to form a battery unit module to achieve a certain voltage level to meet the grid connection requirements of the battery system. During operation, the electrolyte is evenly distributed into each stack module through pumps, pipelines, and other delivery equipment, and circulates between electrolyte storage tanks. The delivery of electrolyte to each stack also connects the potential points between the stacks. Since the electrolyte is a conductor, a conductive path is formed in the flow channels between the stacks, generating bypass current. The generation of bypass current causes leakage losses between the stacks in the system, leading to a decrease in system efficiency. Leakage losses are converted into heat, causing localized temperature rises between the stacks, which not only accelerates material aging but also causes localized electrolyte precipitation, affecting the lifespan of the flow battery. To reduce the impact of flow channels on the bypass current between flow battery stacks, according to the resistance formula R = ρL / S, it is necessary to increase the length of the pipes between the stacks or decrease the pipe diameter to increase the equivalent resistance. The longer the pipe length and the smaller the pipe diameter, the greater the equivalent resistance and the smaller the bypass current in the stack flow channels.

[0004] To address the bypass current issue, CN213150835U discloses a flow battery system that uses a tortuous structure for the electrolyte inlet and outlet pipes of the battery stack to increase channel resistance, thereby effectively reducing bypass current and improving battery efficiency. CN103354294B discloses a pipeline structure for a flow battery system that effectively reduces leakage current in battery systems with multiple battery stacks by rationally coordinating the distribution, extension, and arrangement of pipelines, thus reducing unnecessary energy loss. CN116845310A discloses a flow battery module with a coiled flow channel. This module eliminates the need for a coiled pipeline design, centralizing the coils within a coil box for modularity, facilitating installation, eliminating leakage risk, and allowing the flow channel length to be adjusted according to resistance requirements.

[0005] Most existing technologies increase the equivalent resistance and reduce bypass current by extending the length of the fuel cell stack's inlet / outlet liquid lines. However, these technologies only consider extending the coil and layout to reduce the bypass current of the fuel cell stack, resulting in numerous "U"-shaped coil bends. They do not consider the impact of the coil structure on the system's pump consumption, nor do they comprehensively consider the interrelationships and substitutability between devices from a system perspective. Consequently, the system is not compact enough and occupies a large area. Summary of the Invention

[0006] The purpose of this invention is to provide a multifunctional heat exchange device and a flow battery system, which can reduce the bypass current and resistance drop of the system and improve battery efficiency performance.

[0007] To achieve the above objectives, the first aspect of the present invention provides a multifunctional heat exchange device, which includes a multifunctional heat exchange device body, a mosquito coil disposed in the multifunctional heat exchange device body, a heat exchange medium inlet and a heat exchange medium outlet; the mosquito coil includes a positive electrode coil and a negative electrode coil, which are spirally wound together to form the mosquito coil.

[0008] Optionally, the positive electrode coil and the negative electrode coil are spirally wound around each other from left to right to form the mosquito coil-like coil; the positive electrode coil and the negative electrode coil rotate in opposite directions.

[0009] Optionally, the positive electrode coil and the negative electrode coil are coaxially arranged.

[0010] Optionally, the mosquito coil-type coils are arranged compactly near the inlet and outlet of the heat exchange medium pipe, and sparsely away from the inlet and outlet of the heat exchange medium pipe.

[0011] Optionally, the positive electrode coil includes a positive electrolyte inlet and a positive electrolyte outlet, and the negative electrode coil includes a negative electrolyte inlet and a negative electrolyte outlet; the positive electrolyte inlet and the negative electrolyte inlet are located on the same side and are arranged in parallel, and the positive electrolyte outlet and the negative electrolyte outlet are located on the same side and are arranged in parallel.

[0012] Optionally, the length of the positive electrode coil and the negative electrode coil are each greater than 10m, and the diameter of each is 15-35cm.

[0013] Optionally, the heat exchange medium inlet is located at the top of the multifunctional heat exchanger body, and the heat exchange medium outlet is located at the bottom of the multifunctional heat exchanger body.

[0014] Optionally, the heat exchange medium includes one of water, heat transfer oil, refrigerant, air, and helium.

[0015] Optionally, the positive electrode coil and the negative electrode coil are each made of one of the following materials: polytetrafluoroethylene, Teflon, graphite, and titanium.

[0016] A second aspect of the present invention provides a flow battery system, comprising a positive electrode storage tank, a positive electrode circulation pump, a negative electrode storage tank, a negative electrode circulation pump, a first battery stack, a second battery stack, a third battery stack, a first multifunctional heat exchanger, a second multifunctional heat exchanger, a third multifunctional heat exchanger, and a chiller; the positive electrode circulation pump is installed on the inlet pipe between the positive electrode storage tank and the first, second, and third battery stacks, and the negative electrode circulation pump is installed on the inlet pipe between the negative electrode storage tank and the first, second, and third battery stacks; the first multifunctional heat exchanger is installed at the outlet of the first battery stack, the second multifunctional heat exchanger is installed at the outlet of the second battery stack, and the third multifunctional heat exchanger is installed at the outlet of the third battery stack; the first, second, and third multifunctional heat exchangers are connected to the chiller; each of the first, second, and third multifunctional heat exchangers is independently a multifunctional heat exchanger provided in the first aspect of the present invention.

[0017] Through the above technical solution, this invention optimizes the structure of the heat exchange device by combining the internal flow channel layout and coil, enabling the heat exchange device to simultaneously reduce bypass current and facilitate heat exchange. The coil within the heat exchange device has a mosquito coil-like structure, replacing the U-shaped tube, which significantly reduces the resistance drop caused by bends. Therefore, this invention not only reduces the system's bypass current and resistance drop, improving battery efficiency, but also achieves a compact system design. Furthermore, this invention does not contain a coil box, reducing the space occupied by the flow battery system and possessing significant application value.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0020] Figure 1 This is a schematic diagram of the structure of the multifunctional heat exchange device of the present invention;

[0021] Figure 2 This is a front view of the mosquito coil-type coil of the present invention;

[0022] Figure 3 This is a left view of the mosquito coil of the present invention;

[0023] Figure 4 This is a schematic diagram of the flow battery system containing a multifunctional heat exchange device according to the present invention;

[0024] Figure 5 This is a schematic diagram of a flow battery system containing a coil box in the prior art.

[0025] Explanation of reference numerals in the attached figures

[0026] 1-Positive electrode storage tank; 2-Positive electrode circulation pump; 3-Negative electrode storage tank; 4-Negative electrode circulation pump; 5-First fuel cell stack; 6-Second fuel cell stack; 7-Third fuel cell stack; 8-First coil box; 9-Second coil box; 10-Third coil box; 11-First heat exchanger; 12-Second heat exchanger; 13-Chiller; 14-First multi-functional heat exchange device; 15-Second multi-functional heat exchange device; 16-Third multi-functional heat exchange device; 17-Positive electrode electrolyte inlet; 18-Negative electrode electrolyte inlet; 19-Heat exchange medium pipeline inlet; 20-Multi-functional heat exchange device body; 21-Negative electrode electrolyte outlet; 22-Positive electrode electrolyte outlet; 23-Mosquito coil type coil; 24-Heat exchange medium pipeline outlet. Detailed Implementation

[0027] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0028] This invention comprehensively considers the impact of the structure and layout of the coil on pump consumption and space occupation, analyzes the correlation and substitutability between the flow channel structure and the coil in the heat exchange device, and proposes a multifunctional heat exchange device and flow battery system.

[0029] like Figure 1 As shown, the multifunctional heat exchanger provided by the first aspect of the present invention includes a multifunctional heat exchanger body 20, a mosquito coil 23 disposed in the multifunctional heat exchanger body 20, a heat exchange medium pipeline inlet 19 and a heat exchange medium pipeline outlet 24; the mosquito coil 23 includes a positive electrode coil and a negative electrode coil, and the positive electrode coil and the negative electrode coil are spirally wound together to form the mosquito coil 23.

[0030] This invention optimizes the structure of the heat exchanger by combining the internal flow channel layout and coil, enabling the heat exchanger to simultaneously reduce bypass current and improve heat exchange. The coil within the heat exchanger uses a mosquito coil-like structure instead of a U-shaped tube, significantly reducing the resistance drop caused by bends.

[0031] According to the present invention, optionally, such as Figure 2 and Figure 3As shown, the positive and negative electrode coils are spirally wound around each other from left to right to form the mosquito coil-like coil 23; the positive and negative electrode coils rotate in opposite directions. The spiral winding of the positive and negative electrode coils without bends results in lower flow resistance and pump consumption compared to the more convoluted "U"-shaped structure. Simultaneously, the mosquito coil-like structure has a large heat exchange area, leading to more efficient heat exchange.

[0032] According to the present invention, optionally, the positive electrode coil and the negative electrode coil are arranged coaxially.

[0033] According to the present invention, optionally, the heat exchange medium has a high flow velocity and strong heat exchange capacity near the pipe inlet / outlet, while its flow velocity is slow and dead zones are easily formed far from the pipe inlet / outlet, resulting in weak heat exchange capacity. Therefore, the mosquito coil 23 of the present invention is arranged compactly near the heat exchange medium pipe inlet 19 and outlet 24, and sparsely away from the heat exchange medium pipe inlet 19 and outlet 24. Compact arrangement means that the outer diameter of one spiral turn near the heat exchange medium pipe inlet / outlet is larger than that of other turns; sparse arrangement means that the outer diameter of one spiral turn far from the heat exchange medium pipe inlet / outlet is smaller than that of other turns.

[0034] According to the present invention, optionally, the positive electrode coil includes a positive electrode electrolyte inlet 17 and a positive electrode electrolyte outlet 22, and the negative electrode coil includes a negative electrode electrolyte inlet 18 and a negative electrode electrolyte outlet 21; the positive electrode electrolyte inlet 17 and the negative electrode electrolyte inlet 18 are located on the same side and arranged in parallel, and the positive electrode electrolyte outlet 22 and the negative electrode electrolyte outlet 21 are located on the same side and arranged in parallel.

[0035] According to the present invention, optionally, the length of the positive electrode coil and the negative electrode coil are each independently greater than 10m, and the diameter of each is independently 15-35cm. Through the above embodiments, while ensuring sufficient heat exchange, the bypass current between fuel cells can be effectively reduced.

[0036] According to the present invention, optionally, the heat exchange medium inlet 19 is located at the top of the multifunctional heat exchanger body 20, and the heat exchange medium outlet 24 is located at the bottom of the multifunctional heat exchanger body 20. The heat exchange medium flows from top to bottom through the coil in the multifunctional heat exchanger body, and flows out of the multifunctional heat exchanger after sufficient heat exchange with the coil.

[0037] According to the present invention, optionally, the heat exchange medium includes one of water, heat transfer oil, refrigerant, air, and helium. Commonly used refrigerants can be R22, R407C, R410A, etc.

[0038] According to the present invention, optionally, the electrolyte in the coil of the heat exchange device is mostly acidic / alkaline, so the material of the coil needs to be a material resistant to electrolyte corrosion. For example, the positive electrode coil and the negative electrode coil can be made of one of polytetrafluoroethylene, Teflon, graphite and titanium metal.

[0039] A second aspect of the present invention provides a flow battery system, such as Figure 4 As shown, the system includes a positive electrode storage tank 1, a positive electrode circulation pump 2, a negative electrode storage tank 3, a negative electrode circulation pump 4, an electric stack, a multi-functional heat exchanger, and a chiller 13; the positive electrode circulation pump 2 is installed on the inlet pipe between the positive electrode storage tank 1 and the electric stack, and the negative electrode circulation pump 4 is installed on the inlet pipe between the negative electrode storage tank 3 and the electric stack; the multi-functional heat exchanger is installed at the outlet of the electric stack, and the multi-functional heat exchanger is connected to the chiller 13; the multi-functional heat exchanger is the multi-functional heat exchanger provided in the first aspect of the present invention.

[0040] The multifunctional heat exchange device in the system of this invention can not only reduce the bypass current and resistance drop of the system and improve the battery efficiency performance, but also realize the compact design of the system and make the system piping connection simpler. At the same time, this invention does not contain a coil box, which reduces the space occupied by the flow battery system and has great application value.

[0041] According to the present invention, optionally, the fuel cell stack includes a first fuel cell stack 5, a second fuel cell stack 6, and a third fuel cell stack 7, wherein the positive electrode circulation pump 2 is provided on the liquid inlet pipeline between the positive electrode storage tank 1 and the first fuel cell stack 5, the second fuel cell stack 6, and the third fuel cell stack 7, and the negative electrode circulation pump 4 is provided on the liquid inlet pipeline between the negative electrode storage tank 3 and the first fuel cell stack 5, the second fuel cell stack 6, and the third fuel cell stack 7.

[0042] According to the present invention, optionally, the multifunctional heat exchange device includes a first multifunctional heat exchange device 14, a second multifunctional heat exchange device 15, and a third multifunctional heat exchange device 16. The first multifunctional heat exchange device 14 is disposed at the outlet of the first fuel cell stack 5, the second multifunctional heat exchange device 15 is disposed at the outlet of the second fuel cell stack 6, and the third multifunctional heat exchange device 16 is disposed at the outlet of the third fuel cell stack 7. The first multifunctional heat exchange device 14, the second multifunctional heat exchange device 15, and the third multifunctional heat exchange device 16 are connected to the chiller 13.

[0043] The present invention will be further illustrated by the following examples, but the present invention is not limited thereto.

[0044] Example

[0045] The multifunctional heat exchanger of this embodiment includes a multifunctional heat exchanger body 20, a mosquito coil 23 disposed in the multifunctional heat exchanger body 20, a heat exchange medium inlet 19 disposed at the top of the multifunctional heat exchanger body 20, and a heat exchange medium outlet 24 disposed at the bottom of the multifunctional heat exchanger body 20. The mosquito coil 23 includes a positive electrode coil and a negative electrode coil, which are spirally wound together from left to right to form the mosquito coil 23. The mosquito coil 23 is arranged compactly near the heat exchange medium inlet 19 and the heat exchange medium outlet 24, and sparsely arranged away from the heat exchange medium inlet 19 and the heat exchange medium outlet 24. The positive electrode coil includes a positive electrolyte inlet 17 and a positive electrolyte outlet 22, and the negative electrode coil includes a negative electrolyte inlet 18 and a negative electrolyte outlet 21; the positive electrolyte inlet 17 and the negative electrolyte inlet 18 are located on the same side and are arranged in parallel, and the positive electrolyte outlet 22 and the negative electrolyte outlet 21 are located on the same side and are arranged in parallel.

[0046] The operation process of a flow battery system with a multi-functional heat exchange device is as follows: The positive electrolyte in the positive electrode storage tank 1, under the action of the positive electrode circulation pump 2, enters the first battery stack 5, the second battery stack 6, and the third battery stack 7 through various branches. Similarly, the negative electrolyte in the negative electrode storage tank 3, under the action of the negative electrode circulation pump 4, enters the first battery stack 5, the second battery stack 6, and the third battery stack 7 through various branches. The positive / negative electrolytes passing through the first battery stack 5, the second battery stack 6, and the third battery stack 7 first enter the first multi-functional heat exchange device 14, the second multi-functional heat exchange device 15, and the third multi-functional heat exchange device 16. The positive electrolyte, after heat exchange through the first multi-functional heat exchange device 14, the second multi-functional heat exchange device 15, and the third multi-functional heat exchange device 16, is first collected and then returned to the positive electrode storage tank 1. The negative electrolyte, after heat exchange through the first multi-functional heat exchange device 14, the second multi-functional heat exchange device 15, and the third multi-functional heat exchange device 16, is first collected and then returned to the negative electrode storage tank 3. The heat exchange medium of the first multi-functional heat exchanger 14, the second multi-functional heat exchanger 15, and the third multi-functional heat exchanger 16 all comes from the chiller 13.

[0047] Comparative Example

[0048] like Figure 5 As shown, the flow battery system with coil box in this comparative example includes a positive electrode storage tank 1, a negative electrode storage tank 3, a positive electrode circulation pump 2, a negative electrode circulation pump 4, a first battery stack 5, a second battery stack 6, a third battery stack 7, a first coil box 8, a second coil box 9, a third coil box 10, a first heat exchanger 11, a second heat exchanger 12, and a chiller 13.

[0049] The operation process of a flow battery system with coil boxes is as follows: The positive electrolyte in the positive electrode storage tank 1, under the action of the positive electrode circulation pump 2, enters the first stack 5, the second stack 6, and the third stack 7 through various branches. Similarly, the negative electrolyte in the negative electrode storage tank 3, under the action of the negative electrode circulation pump 4, enters the first stack 5, the second stack 6, and the third stack 7 through various branches. The positive / negative electrolytes from the first stack 5, the second stack 6, and the third stack 7 first enter the first coil box 8, the second coil box 9, and the third coil box 10. The positive electrolytes from the outlets of the first coil box 8, the second coil box 9, and the third coil box 10 first merge and then enter the first heat exchanger 11. The negative electrolytes from the outlets of the first coil box 8, the second coil box 9, and the third coil box 10 first merge and then enter the second heat exchanger 12. The positive electrolyte, after heat exchange in the first heat exchanger 11, returns to the positive electrolyte storage tank 1, and the negative electrolyte, after heat exchange in the second heat exchanger 12, returns to the negative electrolyte storage tank 3. The heat exchange medium for both the first heat exchanger 11 and the second heat exchanger 12 comes from the chiller 13.

[0050] Compared with flow battery systems equipped with coil boxes, the flow battery system of the present invention with a multifunctional heat exchange device has simpler pipe connections, a more compact structure between components, and the combination of coil and heat exchange device eliminates the need for coil boxes, thus reducing the footprint of the flow battery.

[0051] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0052] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0053] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A multifunctional heat exchange device, characterized in that, The multifunctional heat exchange device comprises a multifunctional heat exchange device body, a mosquito coil type coil arranged in the multifunctional heat exchange device body, a heat exchange working medium pipeline inlet and a heat exchange working medium pipeline outlet. The mosquito coil type coil comprises a positive electrode coil and a negative electrode coil, and the positive electrode coil and the negative electrode coil are spirally wound to form the mosquito coil type coil.

2. The multifunctional heat exchanger according to claim 1, wherein The positive electrode coil and the negative electrode coil are spirally wound from left to right.

3. The multifunctional heat exchanger of claim 1, wherein, The positive electrode coil and the negative electrode coil are coaxially arranged.

4. The multifunction heat exchanger of claim 1, wherein, The mosquito coil type coil is arranged compactly near the heat exchange working medium pipeline inlet and the heat exchange working medium pipeline outlet, and is arranged sparsely away from the heat exchange working medium pipeline inlet and the heat exchange working medium pipeline outlet.

5. The multifunctional heat exchanger of claim 1, wherein, The positive electrode coil comprises a positive electrode electrolyte inlet and a positive electrode electrolyte outlet, and the negative electrode coil comprises a negative electrode electrolyte inlet and a negative electrode electrolyte outlet. The positive electrode electrolyte inlet and the negative electrode electrolyte inlet are arranged on the same side and in parallel, and the positive electrode electrolyte outlet and the negative electrode electrolyte outlet are arranged on the same side and in parallel.

6. The multifunction heat exchanger of claim 1, wherein, The length of the positive electrode coil and the negative electrode coil is greater than 10 m, and the diameter of the positive electrode coil and the negative electrode coil is 15-35 cm.

7. The multifunction heat exchanger of claim 1, wherein, The heat exchange working medium pipeline inlet is arranged at the top end of the multifunctional heat exchange device body, and the heat exchange working medium pipeline outlet is arranged at the bottom end of the multifunctional heat exchange device body.

8. The multifunction heat exchanger of claim 1, wherein, The heat exchange working medium comprises one of water, heat-conducting oil, refrigerant, air and helium.

9. The multifunction heat exchanger of claim 1, wherein, The material of the positive electrode coil and the negative electrode coil is one of polytetrafluoroethylene, iron fluoride, graphite and titanium metal.

10. A flow battery system, characterized by, The system comprises a positive electrode liquid storage tank, a positive electrode circulating pump, a negative electrode liquid storage tank, a negative electrode circulating pump, a first electric pile, a second electric pile, a third electric pile, a first multifunctional heat exchange device, a second multifunctional heat exchange device, a third multifunctional heat exchange device and a water chiller. The positive electrode circulating pump is arranged on the liquid inlet pipeline between the positive electrode liquid storage tank and the first electric pile, the second electric pile and the third electric pile, and the negative electrode circulating pump is arranged on the liquid inlet pipeline between the negative electrode liquid storage tank and the first electric pile, the second electric pile and the third electric pile; the outlet of the first electric pile is provided with the first multifunctional heat exchange device, the outlet of the second electric pile is provided with the second multifunctional heat exchange device, the outlet of the third electric pile is provided with the third multifunctional heat exchange device, and the first multifunctional heat exchange device, the second multifunctional heat exchange device and the third multifunctional heat exchange device are connected with the water chiller. The first multifunctional heat exchange device, the second multifunctional heat exchange device and the third multifunctional heat exchange device are each independently the multifunctional heat exchange device of any one of claims 1-9.

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