A leakage current blocking device using a pulsating liquid supply method and a flow battery using the leakage current blocking device

Abstract

This invention discloses a leakage current blocking device employing a pulsed electrolyte supply method and a flow battery using the leakage current blocking device. The technical solution includes a piston cylinder, an inlet pipe for electrolyte to flow into the piston cylinder, an outlet pipe for electrolyte to flow out of the piston cylinder, two-position two-way solenoid valves respectively installed on the two inlet and two outlet pipes, an insulating piston sealing the piston cylinder to block electrolyte current, and limit switches installed on both sides of the piston cylinder to provide actuation signals to the two-position two-way solenoid valves. By controlling the opening and closing of the corresponding solenoid valves, the reciprocating motion of the insulating piston is controlled to achieve pulsed electrolyte supply, ensuring that the inlet and outlet electrolytes block current on both sides of the insulating piston. This invention can completely eliminate bypass leakage current, improve the efficiency of the flow battery system, reduce heat generation, and enhance system reliability. It has a simple structure, small size, and can be modularly installed in a flow battery system.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a leakage current blocking device using a pulsed liquid supply method and a flow battery using the leakage current blocking device. Background Technology

[0002] 1. Flow batteries use an electrolyte solution as the energy storage medium and a fuel cell stack as the reaction site. During charging, a circulating pump drives the electrolyte solution to flow through the stack. During this flow, electrical energy is converted into chemical energy and stored in the electrolyte solution through redox reactions. The process is reversed during discharging. Flow batteries offer advantages such as high reliability, low cost, high efficiency, and environmental friendliness, making them suitable for a wide range of applications.

[0003] 2. Existing flow batteries are produced on a large scale, such as... Figure 1 Electrolyte solution is typically supplied to the main pipeline via a circulating pump. The main pipeline then supplies electrolyte to multiple battery stacks evenly and continuously through branch pipelines. The branch pipelines supplying electrolyte to the battery stacks are connected in parallel. However, during the charging and discharging of a flow battery, multiple battery stacks are typically connected in series in the circuit. Due to the potential difference between the battery stacks and the fact that the electrolyte solution is connected to the main pipeline through branch pipelines, a current is generated in the pipelines. This current does not pass through the load and is called bypass current or leakage current. Its presence reduces the conversion efficiency of the flow battery, and the resistance of the electrolyte solution causes heat generation, which has a negative impact on the battery stack and the system.

[0004] 3. Chinese patent document (patent application number: 201310300685.7) discloses an invention entitled "A Piping Structure for a Flow Battery System." This patent increases the electrolyte resistance in the common piping by distributing and extending the common piping between the battery stacks, thereby reducing leakage current and improving the energy efficiency of the flow battery system. However, its piping is lengthy and occupies a large space, and it can only reduce leakage current, not completely eliminate it. In summary, inventing a device with a simple structure, small size, and the ability to completely eliminate leakage current is of great significance. Summary of the Invention

[0005] This invention addresses the shortcomings and defects of existing technologies by providing a leakage current blocking device using a pulsed liquid supply method and a flow battery using the leakage current blocking device. By installing the leakage current blocking device using the pulsed liquid supply method in the liquid supply pipe that generates leakage current in the flow battery system, the problem of reduced system efficiency and heat generation caused by leakage current in the multi-stack series scheme of the flow battery circuit can be completely eliminated, thereby improving the efficiency and reliability of the flow battery system.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A leakage current blocking device with a pulsed liquid supply method includes a piston cylinder body 3.3, a leakage current blocking device inlet pipe 3.1, a leakage current blocking device outlet pipe 3.6, a leakage current blocking device main inlet pipe 3.1.1 connected to the negative electrode electrolyte outlet pipe 1.3.2 or the positive electrode electrolyte outlet pipe 1.4.2, a leakage current blocking device branch inlet pipe 3.1.2 (one outlet and two outlets) connected to the main inlet pipe 3.1.1, a two-position two-way solenoid valve 3.10 installed between the cavity 1QT1 and the leakage current blocking device branch inlet pipe 3.1.2, a two-position two-way solenoid valve 3.2 installed between the cavity 2QT2 and the leakage current blocking device branch inlet pipe 3.1.2, and a piston cylinder body 3.3. The system includes: an insulating piston 3.8 for sealing the cylinder body 3.3 to block the current of the electrolyte solution in the two chambers 1QT1 and 2QT2; a two-position two-way solenoid valve 3.7 installed between the outlet pipe 3.6.2 of the leakage current blocking device and the cylinder body 3.3; a two-position two-way solenoid valve 3.5 installed between the outlet pipe 3.6.2 of the leakage current blocking device and the outlet pipe 3.6.2 of the leakage current blocking device; the outlet pipe 3.6.2 of the leakage current blocking device; the main outlet pipe 3.6.1 of the leakage current blocking device connected to the two outlet pipes 3.6.2 of the leakage current blocking device; and limit switches 3.4 and 3.9 that provide actuation signal commands to the two-position two-way solenoid valves 3.2, 3.5, 3.7 and 3.10.

[0008] The leakage current device inlet pipe 3.1 includes: a main leakage current blocking device inlet pipe 3.1.1 connected to the negative electrode electrolyte outlet pipe 1.32 or the negative electrode electrolyte outlet pipe 1.4.2, and a secondary pipe that is divided into two leakage current blocking device inlet branches 3.1.2 from the main leakage current blocking device inlet pipe 3.1.1 and connected to the piston cylinder body inlet.

[0009] In the preferred embodiment of the above scheme, a two-position two-way solenoid directional valve is installed in the middle of the liquid inlet pipe 3.1.2 of each leakage current blocking device.

[0010] The leakage current device outlet pipe 3.6 includes: a leakage current blocking device main outlet pipe 3.6.1 connected to the negative electrode electrolyte outlet pipe 1.32 or the negative electrode electrolyte outlet pipe 1.4.2, a two-way leakage current blocking device return pipe 3.6.2, and a leakage current blocking device inlet main pipe 3.1.1 connected thereto;

[0011] In the preferred embodiment of the above schemes, a two-position two-way solenoid directional valve is installed in the middle of the return liquid distribution pipe 3.6.2 of each leakage current blocking device.

[0012] The liquid outlet pipeline includes: a secondary liquid outlet pipe connected to the piston cylinder body, and a main liquid outlet pipe directly connected to the secondary liquid outlet pipe and the bypass.

[0013] In the preferred embodiment of the above scheme, the two-position two-way solenoid directional valve 3.2 and the two-position two-way solenoid directional valve 3.7 are in the same connected and disconnected state, the two-position two-way solenoid directional valve 3.5 and the two-position two-way solenoid directional valve 3.10 are in the same connected and disconnected state, and the two-position two-way solenoid directional valve 3.2 and the two-position two-way solenoid directional valve 3.5 are in opposite connected and disconnected states.

[0014] The limit switches 3.4 and 3.9 are installed on both sides of the piston cylinder body 3.3 along the movement direction of the insulating piston 3.8;

[0015] Furthermore, after any one of the limit switches 3.4 and 3.9 issues a signal, the two-position two-way solenoid valves 3.2, 3.5, 3.7, and 3.10 simultaneously switch on / off states.

[0016] The beneficial technical effects of this invention are: it can completely eliminate bypass leakage current, improve the efficiency of the flow battery system, reduce heat generation, and enhance system reliability. The overall structure is simple and compact, and it can be modularly installed in the required positions within the flow battery system, offering flexibility and convenience. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the existing flow battery technology.

[0018] Figure 2 This is a schematic diagram of the flow battery structure of Example 1 of the present invention.

[0019] Figure 3 This is a schematic diagram of a leakage current blocking device using a pulsed liquid supply method.

[0020] Figure 4 yes Figure 3 Another working state

[0021] Reference numerals in the attached diagram: 1.1 Negative electrode electrolyte storage tank; 1.2.1 Negative electrode electrolyte circulation pump; 1.2.2 Positive electrode electrolyte circulation pump; 1.3.1 Main outlet pipe for negative electrode electrolyte; 1.3.2 Outlet pipe for negative electrode electrolyte; 1.4.1 Main outlet pipe for positive electrode electrolyte; 1.4.2 Outlet pipe for positive electrode electrolyte; 1.5 Positive electrode electrolyte storage tank; 1.6 Positive electrode electrolyte solution; 1.7.1 Main return pipe for positive electrode electrolyte; 1.7.2 Outlet pipe for positive electrode electrolyte; 1.8 Fuel cell stack; 1.9.1 Main return pipe for negative electrode electrolyte; 1.9.2 Return pipe for negative electrode electrolyte. From the pipeline, 1.10 negative electrode electrolyte solution, 2.1 leakage current blocking device with pulsed liquid supply, 3.1 leakage current device inlet pipeline, 3.1.1 leakage current blocking device main inlet pipeline, 3.1.2 leakage current blocking device branch inlet pipeline, 3.2 check valve, 3.3 piston cylinder body, 3.4 limit switch, 3.5 two-position two-way solenoid directional valve, 3.6.1 leakage current blocking device main outlet pipeline, 3.6.2 leakage current blocking device branch outlet pipeline, QT1 cavity 1, QT2 cavity 2, 3.7 two-position two-way solenoid directional valve, 3.8 insulated piston, 3.9 limit switch. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and do not limit the scope of the invention.

[0023] Example 1.

[0024] like Figure 2 As shown, this is a flow battery that uses a leakage current blocking device, specifically including a flow battery liquid supply system and a leakage current blocking device with a pulsed liquid supply method.

[0025] The flow battery system is specifically as follows: the negative electrolyte solution 1.10 is supplied from the negative electrolyte storage tank 1.1, which stores the negative electrolyte solution, to the negative electrolyte outlet main pipe 1.3.1 via the circulation pump 1.2.1. It then flows sequentially through the negative electrolyte outlet pipe, the leakage current blocking device 2.1 with the pulsating supply method, the fuel cell stack 1.8, the negative electrolyte return pipe 1.9.2, and the negative electrolyte return main pipe 1.9.1, and finally flows back to the positive electrolyte return pipe 1.1. The positive electrolyte solution 1.6 is supplied from the positive electrolyte storage tank 1.5 to the positive electrolyte outlet main pipeline 1.4.1 via the circulation pump 1.2.2, and then flows sequentially through the positive electrolyte outlet pipeline 1.4.2, the fuel cell stack 1.8, the positive electrolyte return pipeline 1.7.1, and the positive electrolyte return main pipeline 1.7.1, and finally flows back to the positive electrolyte storage tank 1.5.

[0026] The structure of the leakage current blocking device 2.1 for the pulsed liquid supply method is detailed in [reference needed]. Figure 3 and Figure 4 Specifically, it includes: a main inlet pipe 3.1.1 for the leakage current blocking device connected to the negative electrolyte outlet pipe 1.3.2 or the positive electrolyte outlet pipe 1.4.2; a branch inlet pipe 3.1.2 for the leakage current blocking device; an insulating piston 3.8 that isolates the electrolyte solution circuit in the two chambers of the piston cylinder; two-position two-way solenoid valves 3.2 and 3.5 that prevent electrolyte solution backflow, change the electrolyte solution and are connected to QT2 in the cylinder; two-position two-way solenoid valves 3.7 and 3.10 that prevent electrolyte solution backflow, change the electrolyte solution and are connected to QT1 in the cylinder; limit switches 3.4 and 3.9 that provide action command signals to the two-position two-way solenoid valves 3.2, 3.5, 3.7 and 3.10; a branch outlet pipe 3.6.2 for the leakage current blocking device connected to the two-position two-way solenoid valves 3.5 and 3.7; and a main outlet pipe 3.6.1 for the leakage current blocking device.

[0027] The leakage current blocking device 2.1 using the pulsed liquid supply method in this example operates on the following principle: Taking the pulsed liquid supply method leakage current blocking device connected to the negative electrode electrolyte outlet from pipe 1.3.2 as an example, the pulsed liquid supply method leakage current blocking device has two working states. Working state 1 is as follows: Figure 3 As shown, the negative electrode electrolyte solution 1.10 flows from the negative electrode electrolyte outlet through pipe 1.3.2 into the main inlet pipe 3.1.1 of the leakage current device. Because the two-position two-way solenoid valves 3.5 and 3.10 are in the off state and the two-position two-way solenoid valves 3.3 and 3.7 are in the connected state, the electrolyte solution pressure in cavity 1QT1 on one side of the insulating piston 3.8 is less than the electrolyte solution pressure in cavity 2QT2 on the other side of the insulating piston 3.8. The pressure difference pushes the insulating pistons 3 and 8 towards the limit switch 3.9, and the cavity 1QT... The negative electrode electrolyte solution in chamber 1QT1 is compressed. The negative electrode electrolyte solution 1.10 in chamber 1QT1 can only flow through the two-position two-way solenoid directional valve 3.7 sequentially to the leakage current blocking device outlet pipe 3.6.2 and the leakage current blocking device inlet main pipe 3.6.1, and finally into the fuel cell stack. As the insulating piston 3.8 moves towards the limit opening pipe 3.9, it finally triggers the limit switch 3.9. The limit switch 3.9 sends a signal, causing the two-position two-way solenoid directional valves 3.2, 3.5, 3.7 and 3.10 to switch positions, entering working state 2. Working state 2 is as follows. Figure 4As shown, the negative electrode electrolyte solution 1.10 flows from pipe 1.3.2 into the main inlet pipe 3.1.1 of the leakage current device through the negative electrode electrolyte outlet. Because the two-position two-way solenoid valves 3.3 and 3.7 are in the off state and the two-position two-way solenoid valves 3.5 and 3.10 are in the connected state, the electrolyte solution pressure in the cavity 2QT2 on one side of the insulating piston 3.8 is less than the electrolyte solution pressure in the cavity 2QT2 on the other side of the insulating piston 3.8. The pressure difference pushes the insulating piston 3.8 to move towards the limit switch 3.4. The negative electrode electrolyte solution in the cavity 2QT2... The electrolyte solution is compressed, and the negative electrolyte solution 1.10 in cavity 2QT2 can only flow sequentially through the two-position two-way solenoid valve 3.5 to the outlet pipe 3.6.2 and the inlet main pipe 3.6.1 of the leakage current blocking device, and finally into the fuel cell stack. As the insulating piston 3.8 moves towards the limit opening pipe 3.4, it triggers the limit switch 3.4. The limit switch 3.4 sends a signal, causing the two-position two-way solenoid valves 3.2, 3.5, 3.7, and 3.10 to switch positions, entering working state 1, and working cyclically. Because the insulating piston 8 isolates the negative electrolyte solution 1.10 between cavity 1QT1 and wall QT2 during operation, the current loop generated between the two fuel cell stacks due to the voltage difference is in an open circuit state at the position of the insulating piston 8, thus completely eliminating the leakage current between the fuel cell stacks.

[0028] The above embodiments are descriptions of specific implementations of the present invention, and not limitations thereof. Those skilled in the art can make various modifications and changes without departing from the spirit and scope of the present invention to obtain corresponding equivalent technical solutions. Therefore, all equivalent technical solutions should be included in the patent protection scope of the present invention.

Claims

1. A leakage current blocking device employing a pulsed liquid supply method, characterized in that, This includes the piston cylinder body 3.3, the leakage current device inlet pipe 3.1, the leakage current device outlet pipe 3.6, the leakage current blocking device main inlet pipe 3.1.1 connected to the negative electrolyte outlet pipe 1.3.2 or the positive electrolyte outlet pipe 1.4.2, the leakage current blocking device main inlet pipe 3.1.1 with one outlet and two outlets 3.1.2, the two-position two-way solenoid directional valve 3.1.0 installed between the cavity 1QT1 and the leakage current blocking device inlet branch pipe 3.1.2, the two-position two-way solenoid directional valve 3.2 installed between the cavity 2QT2 and the leakage current blocking device inlet branch pipe 3.1.2, and the piston cylinder body 3.3 sealed with... The following components are included: an insulating piston 3.8 that blocks the current of the electrolyte solution in cavities 1QT1 and 2QT2; a two-position two-way solenoid valve 3.7 installed between cavity 1QT1 and the outlet pipe 3.6.2 of the leakage current blocking device; a two-position two-way solenoid valve 3.5 installed between cavity 2QT2 and the outlet pipe 3.6.2 of the leakage current blocking device; the outlet pipe 3.6.2 of the leakage current blocking device; the main outlet pipe 3.6.1 of the leakage current blocking device connected to the two outlet pipes 3.6.2 of the leakage current blocking device; and limit switches 3.4 and 3.9 that provide actuation signal commands to the two-position two-way solenoid valves 3.2, 3.5, 3.7 and 3.

10.

2. The leakage current blocking device using a pulsed liquid supply method according to claim 1, characterized in that, The insulating piston 3.8 and the piston cylinder 3.3 are sealed.

3. The leakage current blocking device using a pulsed liquid supply method according to claim 1, characterized in that, The two-position two-way solenoid directional valve 3.2 and the two-position two-way solenoid directional valve 3.7 are in the same connected and disconnected state, the two-position two-way solenoid directional valve 3.5 and the two-position two-way solenoid directional valve 3.10 are in the same connected and disconnected state, and the two-position two-way solenoid directional valve 3.2 and the two-position two-way solenoid directional valve 3.5 are in opposite connected and disconnected states.

4. A leakage current blocking device using a pulsed liquid supply method according to claim 1, characterized in that, The limit switches 3.4 and 3.9 are installed on both sides of the piston cylinder body 3.3 along the movement direction of the insulating piston 3.

8.

5. A leakage current blocking device using a pulsed liquid supply method according to claim 4, characterized in that, When any one of the limit switches 3.4 and 3.9 issues a signal, the two-position two-way solenoid valves 3.2, 3.5, 3.7, and 3.10 simultaneously switch on / off states.

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