Liquid flow energy storage heat exchange system

Abstract

The utility model belongs to the technical field of flow batteries, and particularly relates to a flow energy storage heat exchange system. The liquid flow energy storage heat exchange system comprises a liquid storage tank, an electric pile, a third valve, an insulating SiC heat exchanger and a second valve; the liquid storage tank is communicated to the galvanic pile through an electrolyte outflow pipeline, the galvanic pile is communicated to an electrolyte return pipeline through a heat exchange pipeline, the galvanic pile is further communicated to the electrolyte return pipeline through a first pipeline, and the electrolyte return pipeline is communicated to the liquid storage tank; an insulating SiC heat exchanger and a third valve are arranged on the heat exchange pipeline; and a second valve is arranged on the first pipeline. The heat exchanger is an insulating SiC heat exchanger, and the pipeline where the heat exchanger is located is in bypass design. Compared with the mode that the heat exchanger is connected with the electric pile in series, in the system, when heat exchange is not needed, the electrolyte does not pass through the insulating SiC heat exchanger, and therefore the flow resistance cannot be obviously improved. Compared with the mode that the heat exchanger is connected with the electric pile in parallel, in the system, the flow of the pump does not need to be increased, and therefore energy loss cannot be increased.

Description

Technical Field

[0001] The utility model belongs to the technical field of liquid flow batteries, and in particular relates to a liquid flow energy storage and heat exchange system. Background Art

[0002] The carrier used in the liquid flow energy storage system is a charged acidic fluid (i.e., electrolyte, referred to as electrolyte in this article). The commonly used carrier or contact material is a corrosion-resistant plastic material. The corrosion resistance and electrical conductivity of the metal heat exchanger, a commonly used high-efficiency heat exchanger in engineering, cannot meet the requirements. Therefore, the commonly used heat exchange material for the liquid flow energy storage system is Teflon (FEP). The Teflon heat exchanger is generally made of slender Teflon capillaries, with a low heat transfer coefficient and a large heat transfer area. There are two ways to arrange the Teflon heat exchanger: one is to connect the heat exchanger to the battery stack in parallel (see the dotted part in the figure) or in series. If the parallel method is used, the flow rate of the pump needs to be increased, resulting in a large capacity loss. If the series method with the battery stack is used, the heat exchange tube of the Teflon heat exchanger is generally composed of small-diameter capillaries, and the tube loss pressure is large. The other is to use an immersed heat exchanger, that is, the heat exchanger is immersed in the liquid storage tank. Since the electrolyte cannot be stirred, the heat exchange of the system is uneven.

[0003] In addition, Teflon is an inefficient heat exchange material with low thermal conductivity, low heat exchange efficiency, and large space occupation. General metal heat exchangers are not suitable for liquid flow energy storage systems due to their poor acid resistance. Titanium alloys are expensive when used as heat exchangers for liquid flow energy storage systems. At the same time, due to the influence of precipitates, they are not suitable for long-term use.

[0004] In order to solve the above problems, this application is proposed. Utility Model Content

[0005] The utility model provides a liquid flow energy storage and heat exchange system, which comprises: a liquid storage tank 1, a battery stack 4, a third valve 5, an insulating SiC heat exchanger 6, and a second valve 7;

[0006] The outlet of the liquid storage tank 1 is connected to the electrolyte inlet of the battery stack 4 through the electrolyte outflow pipeline 01, and the electrolyte outlet of the battery stack 4 is connected to the upstream section of the electrolyte return pipeline 04 through the heat exchange pipeline 02. The electrolyte outlet of the battery stack 4 is also connected to the upstream section of the electrolyte return pipeline 04 through the first pipeline 03, and the downstream section of the electrolyte return pipeline 04 is connected to the inlet of the liquid storage tank 1;

[0007] The heat exchange pipeline 02 is provided with an insulated SiC heat exchanger 6 and a third valve 5 located upstream of the insulated SiC heat exchanger 6;

[0008] The electrolyte outflow pipeline 01 is provided with a first pump 3 and a first valve 2 .

[0009] The first pipeline 03 is provided with a second valve 7 .

[0010] Preferably, the insulated SiC heat exchanger 6 comprises a SiC tube bundle 6-5, an inlet 6-1 and an outlet 6-2 connected to the SiC tube bundle 6-5;

[0011] The inlet 6-1 is provided with an inlet pressure sensor 6-7 and an inlet temperature sensor 6-8;

[0012] An outlet pressure sensor 6-10 and an outlet temperature sensor 6-9 are provided at the outlet 6-2.

[0013] In the present application, the flow direction of the electrolyte is recorded as from upstream to downstream.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] 1. In the present application, the heat exchanger adopts an insulated SiC heat exchanger, and the pipeline where the heat exchanger is located is a bypass design. When the electrolyte needs to exchange heat, the third valve 5 is opened, the second valve 7 is closed, and the electrolyte enters the insulated SiC heat exchanger 6 for heat exchange, and the electrolyte after heat exchange returns to the liquid storage tank 1. When heat exchange is not required, the third valve 5 is closed, the second valve 7 is opened, and the electrolyte does not pass through the insulated SiC heat exchanger 6 and directly flows back to the liquid storage tank 1.

[0016] Compared with the method of connecting the heat exchanger and the fuel cell stack in series, in the system of the present application, when heat exchange is not required, the electrolyte does not pass through the insulating SiC heat exchanger 6, so the flow resistance will not be significantly increased.

[0017] Compared to the method of connecting the heat exchanger in parallel with the fuel cell stack, in the system of the present application, there is no need to increase the flow rate of the pump, and therefore the energy loss will not increase.

[0018] 2. The heat exchanger of this application uses insulated SiC tubes as the heat exchange material. SiC tubes are a kind of corrosion-resistant material with extremely high thermal conductivity. Its thermal conductivity is 7 times that of stainless steel tube heat exchangers and 60 times that of Teflon heat exchangers. Compared with Teflon heat exchangers, heat exchangers made of SiC tubes have a smaller heat exchange area and higher heat exchange efficiency. For example, a 12KW heat exchanger requires about 4㎡ with a Teflon heat exchanger, while a heat exchanger made of SiC tubes only needs 0.1㎡ or even less heat exchange area to fully meet the requirements, saving the installation space of the heat exchanger. Using insulated SiC tubes to make heat exchangers has great advantages, especially for container-type energy storage systems that require increasingly larger energy units. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the position of a Teflon heat exchanger installed in a liquid flow energy storage heat exchange system in the prior art.

[0020] Figure 2 This is a schematic diagram of the liquid flow energy storage and heat exchange system of the present application.

[0021] Figure 3 This is a schematic diagram of the structure of the insulated SiC heat exchanger 6 in the liquid flow energy storage heat exchange system of the present application.

[0022] Figure 4 for Figure 3 AA section view in.

[0023] List of reference numerals:

[0024] 1. Liquid storage tank, 2. First valve, 3. First pump, 4. Fuel cell stack, 5. Third valve, 6. Insulated SiC heat exchanger, 6-1. Inlet, 6-2. Outlet, 6-3. Coolant inlet, 6-4. Coolant outlet, 6-5. Insulated SiC tube bundle, 6-6. Heat exchanger shell, 6-7. Inlet pressure sensor, 6-8. Inlet temperature sensor, 6-9. Outlet temperature sensor, 6-10. Outlet pressure sensor, 7. Second valve, 8. Storage tank temperature sensor, 9. Teflon heat exchanger, 01. Electrolyte outflow pipeline, 02. Heat exchange pipeline, 03. First pipeline, 04. Electrolyte reflux pipeline. DETAILED DESCRIPTION

[0025] The utility model is further described in detail below in conjunction with the embodiments.

[0026] Those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If the manufacturer of the materials or equipment used is not specified, they are all conventional products that can be purchased.

[0027] Those skilled in the art will appreciate that, unless expressly stated otherwise, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present utility model refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. It should be understood that when we refer to an element as being "connected" to another element, it may be directly connected to the other element, or there may be intermediate elements. In addition, the "connection" used here may include wireless connection.

[0028] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two. The terms "inside", "upper", "lower", etc., indicating positions or state relationships, are based on the positions or state relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operate in a specific position, and therefore cannot be understood as limiting the present invention.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "provided with" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention will be understood according to specific circumstances.

[0030] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein, including technical terms and scientific terms, have the same meaning as the general understanding of ordinary technicians in the field to which the utility model belongs. It should also be understood that those terms such as those defined in general dictionaries should be understood to have the same meaning as the meaning in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0031] like Figure 2-4 , a liquid flow energy storage heat exchange system, the liquid flow energy storage heat exchange system comprising: a liquid storage tank 1, a battery stack 4, a third valve 5, an insulating SiC heat exchanger 6, and a second valve 7;

[0032] The outlet of the liquid storage tank 1 is connected to the electrolyte inlet of the battery stack 4 through the electrolyte outflow pipeline 01, and the electrolyte outlet of the battery stack 4 is connected to the upstream section of the electrolyte return pipeline 04 through the heat exchange pipeline 02. The electrolyte outlet of the battery stack 4 is also connected to the upstream section of the electrolyte return pipeline 04 through the first pipeline 03, and the downstream section of the electrolyte return pipeline 04 is connected to the inlet of the liquid storage tank 1;

[0033] The heat exchange pipeline 02 is provided with an insulated SiC heat exchanger 6 and a third valve 5 located upstream of the insulated SiC heat exchanger 6;

[0034] The electrolyte outflow pipeline 01 is provided with a first pump 3 and a first valve 2. The first pipeline 03 is provided with a second valve 7.

[0035] Specifically, the first pump 3 is a magnetic pump. The first valve 2 is a butterfly valve. The third valve 5 and the second valve 7 are both electric valves. The insulated SiC heat exchanger 6 includes a SiC tube bundle 6-5, an inlet 6-1 and an outlet 6-2 connected to the SiC tube bundle 6-5. An inlet pressure sensor 6-7 and an inlet temperature sensor 6-8 are provided at the inlet 6-1 to monitor the pressure and temperature of the electrolyte at the inlet 6-1. An outlet pressure sensor 6-10 and an outlet temperature sensor 6-9 are provided at the outlet 6-2 to monitor the pressure and temperature of the electrolyte at the outlet 6-2.

[0036] The liquid storage tank 1 is provided with a tank temperature sensor 8 to monitor the temperature of the electrolyte in the liquid storage tank 1 .

[0037] The working mode of the above liquid flow energy storage heat exchange system is as follows:

[0038] Under the action of the energy supply unit - the first pump 3, the electrolyte is sequentially pumped from the positive electrode or the negative electrode to the Figure 2 Only the positive electrode storage tank 1 is displayed, and the electrolyte flows through the electrolyte outflow pipeline 01, passes through the first valve 2, and the first pump 3 to enter the battery stack 4. When the monitoring system detects through the tank temperature sensor 8 that the temperature of the electrolyte in the storage tank 1 exceeds the operating temperature and needs to be cooled, the third valve 5 is opened and the second valve 7 is closed, and the electrolyte enters the insulating SiC heat exchanger 6 through the heat exchange pipeline 02 for heat exchange, and the electrolyte after heat exchange returns to the storage tank 1. When the system detects through the tank temperature sensor 8 that the temperature of the electrolyte in the storage tank 1 is at the normal value of the system operation and no heat exchange / cooling is required, the third valve 5 is closed, the second valve 7 is opened, and the electrolyte does not pass through the insulating SiC heat exchanger 6, and directly flows back to the storage tank 1 through the electrolyte outflow pipeline 01, the first pipeline 03, and the electrolyte return pipeline 04.

[0039] When the electrolyte flows through the insulated SiC heat exchanger 6, the inlet pressure sensor 6-7 and the inlet temperature sensor 6-8 at the inlet 6-1 monitor the temperature and pressure of the electrolyte and transmit them to the monitoring system. The electrolyte enters the insulated SiC heat exchanger 6 body, flows to the outlet 6-2 after passing through the SiC tube bundle 6-5, and the outlet pressure sensor 6-10 and the outlet temperature sensor 6-9 at the outlet monitor the temperature and pressure of the electrolyte and transmit them to the monitoring system to determine whether the heat exchange of the heat exchanger meets the requirements. The coolant flows into the heat exchanger shell 6-6 from the coolant inlet 6-3, and passes through the coolant outlet 6-4 after heat exchange. Temperature instruments and pressure gauges can also be set at the inlet and outlet of the coolant to observe or monitor the temperature and pressure of the coolant.

[0040] Before manufacturing the insulated SiC heat exchanger 6, an immersion test shall be carried out on the insulated SiC tube, and the test results shall meet the requirements of NB / T42133-2017.

Claims

1. A liquid flow energy storage heat exchange system, characterized in that: The liquid flow energy storage and heat exchange system comprises: a liquid storage tank (1), a fuel cell stack (4), a third valve (5), an insulating SiC heat exchanger (6), and a second valve (7); The outlet of the liquid storage tank (1) is connected to the electrolyte inlet of the battery stack (4) through an electrolyte outflow pipeline (01), the electrolyte outlet of the battery stack (4) is connected to the upstream section of the electrolyte return pipeline (04) through a heat exchange pipeline (02), the electrolyte outlet of the battery stack (4) is also connected to the upstream section of the electrolyte return pipeline (04) through a first pipeline (03), and the downstream section of the electrolyte return pipeline (04) is connected to the inlet of the liquid storage tank (1); The heat exchange pipeline (02) is provided with an insulated SiC heat exchanger (6) and a third valve (5) located upstream of the insulated SiC heat exchanger (6); The electrolyte outflow pipeline (01) is provided with a first pump (3) and a first valve (2); A second valve (7) is provided on the first pipeline (03).

2. The liquid flow energy storage heat exchange system according to claim 1, characterized in that: The insulated SiC heat exchanger (6) comprises: a SiC tube bundle (6-5), an inlet (6-1) and an outlet (6-2) connected to the SiC tube bundle (6-5); An inlet pressure sensor (6-7) and an inlet temperature sensor (6-8) are provided at the inlet (6-1); An outlet pressure sensor (6-10) and an outlet temperature sensor (6-9) are provided at the outlet (6-2); The liquid storage tank (1) is provided with a tank temperature sensor (8) to monitor the temperature of the electrolyte therein.

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