Alkali liquor electrolytic bath marshalling waste heat utilization system

Abstract

The embodiment of the invention provides an alkali liquor electrolytic bath marshalling waste heat utilization system which comprises at least two groups of electrolytic bath assemblies, each electrolytic bath assembly at least comprises an electrolytic bath and a heat exchanger correspondingly connected with the electrolytic bath, and each heat exchanger is provided with a cooling liquid inlet and a cooling liquid outlet; the waste heat recycling pipe can be respectively communicated with each cooling liquid inlet and each cooling liquid outlet; and when the electrolytic cell in the shutdown standby state exists, the waste heat recycling pipe can obtain heat of the electrolytic cell in the working state through the heat exchanger and provide the obtained heat for the heat exchanger connected with the electrolytic cell in the shutdown standby state so as to heat the electrolytic cell in the shutdown standby state. According to the embodiment of the invention, the waste heat recycling pipe is arranged, so that waste heat generated by the electrolytic bath in the working state can be transferred and utilized, the heat is provided for the electrolytic bath needing hot standby for heat preservation and preheating, and the utilization efficiency of the heat is improved.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen production by electrolysis of alkaline water, and in particular to a waste heat utilization system of an alkali solution electrolysis cell group. Background Art

[0002] In recent years, with the large-scale utilization of renewable energy, one electrolyzer often cannot meet the demand in the hydrogen production process. In the implementation of the project, a group of several electrolyzers is often used to work in groups to save the construction cost of auxiliary facilities. However, renewable energy itself is intermittent and volatile, and the electrolyzer group cannot always guarantee constant load operation. The increase or decrease of the number of working units in the electrolyzer group becomes a necessary adjustment means. The standby electrolyzer must be able to start and enter the normal working state at any time, so that the standby electrolyzer on standby must always be kept hot; on the other hand, the working electrolyzer will generate a lot of heat and need to be cooled. For example, the Chinese patent with the authorization announcement number CN213295524U discloses a comprehensive heat treatment system for circulating water of a hydrogen production device, including an electrolyzer and a heat storage tank. The heat storage tank is used to store heat. When the electrolyzer is temporarily stopped, the heat of the heat storage tank is relied on to maintain the temperature of the alkali solution. It is necessary to add additional heat storage tank equipment and a heat exchanger between the electrolyzer and the heat storage tank, which increases the production cost; and when the temperature in the heat storage tank continues to rise, its cooling capacity will decrease, which will seriously affect the stability of the working electrolyzer. Summary of the invention

[0003] The present application embodiment proposes a system for utilizing waste heat from a group of alkali liquid electrolytic cells, comprising:

[0004] At least two groups of electrolytic cell assemblies, each of which comprises at least an electrolytic cell and a correspondingly connected heat exchanger, each of which is provided with a coolant inlet and a coolant outlet;

[0005] A waste heat recycling pipe, wherein the waste heat recycling pipe can be connected to each of the coolant inlets and each of the coolant outlets respectively;

[0006] When there is an electrolytic cell in a shutdown standby state, the waste heat recycling pipe can obtain the heat of the electrolytic cell in a working state through a heat exchanger, and provide the obtained heat to the electrolytic cell in a shutdown standby state for heating treatment.

[0007] In some embodiments, the coolant inlet and the coolant outlet are respectively connected to a liquid inlet pipe and a liquid outlet pipe, and the other ends of the liquid inlet pipe and the liquid outlet pipe can be respectively connected to the waste heat recycling pipe to form a waste heat supply branch and a waste heat recovery branch.

[0008] In some embodiments, the waste heat supply branch is provided with a waste heat inlet switching valve, and the waste heat recovery branch is provided with a waste heat outlet switching valve.

[0009] In some embodiments, the alkali liquid electrolytic cell group waste heat utilization system also includes: a coolant inlet main pipe and a coolant return main pipe, and the coolant inlet main pipe and the coolant return main pipe can be connected to the inlet pipe and the outlet pipe respectively to form a coolant supply pipeline and a coolant recovery pipeline.

[0010] In some embodiments, the coolant supply pipeline and the coolant recovery pipeline are respectively provided with a liquid inlet switching valve and a liquid outlet switching valve.

[0011] In some embodiments, a temperature regulating valve is provided on the liquid inlet pipeline at the rear end of the coolant inlet main pipe, and the temperature regulating valve is used to adjust the inlet amount of the coolant when the coolant pipeline is connected.

[0012] In some embodiments, an alkali liquid inlet and an alkali liquid outlet are provided on both sides of the heat exchanger; the heat exchange channel in the heat exchanger guides the flow direction of the alkali liquid from the alkali liquid inlet to the alkali liquid outlet, which is inconsistent with the flow direction of the coolant from the coolant inlet to the coolant outlet.

[0013] In some embodiments, a thermometer is provided near the alkali solution outlet, and the thermometer is used to measure the temperature of the alkali solution flowing out of the heat exchanger.

[0014] In some embodiments, the electrolyzer assembly further includes a hydrogen separator and an oxygen separator, wherein the hydrogen separator and the oxygen separator are respectively connected to the outlet of the electrolyzer; the hydrogen separator and the oxygen separator are both provided with a liquid outlet, and each of the liquid outlets is connected to the alkali solution inlet.

[0015] In some embodiments, the electrolytic cell assembly further comprises an alkali solution circulation pump, one end of which is connected to the alkali solution inlet, and the other end of which is connected to each of the liquid outlets.

[0016] Compared with the prior art, the beneficial effect of the embodiments of the present application is that in the waste heat utilization system of the alkali liquid electrolytic cell group provided by the embodiments of the present application, by setting a waste heat recycling pipe, the waste heat generated by the electrolytic cell in working state can be transferred and utilized as needed, and the heat can be provided to the electrolytic cell that needs hot standby for insulation and preheating, thereby improving the heat utilization efficiency, and there is no need to add additional large equipment such as heat accumulators, thereby avoiding the problem of increased operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] Figure 1 A schematic diagram of a waste heat utilization system for an alkali solution electrolytic cell group provided in an embodiment of the present application.

[0019] The components indicated by the reference numerals in the figures are:

[0020] 110-first electrolytic cell assembly; 112-first heat exchanger; 1121-first coolant inlet; 1122-first coolant outlet; 120-second electrolytic cell assembly; 122-second heat exchanger; 1221-second coolant inlet; 1222-second coolant outlet; 1223 (1123)-alkali solution inlet; 1224 (1124)-alkali solution outlet; 1224a (1124a)-thermometer; 123 (113)-inlet Liquid pipeline; 124 (114)-liquid outlet pipeline; 200-waste heat recycling pipe; 210-waste heat supply branch; 211-waste heat inlet switching valve; 220-waste heat recovery branch; 221-waste heat outlet switching valve; 300-cooling liquid inlet main pipe; 310-cooling liquid supply pipeline; 311-liquid inlet switching valve; 312-temperature regulating valve; 400-cooling liquid return main pipe; 410-cooling liquid recovery pipeline; 411-liquid outlet switching valve. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiment of the present application clearer, the technical solution of the embodiment of the present application will be clearly and completely described in conjunction with the drawings of the embodiment of the present application. Obviously, the described embodiment is a part of the embodiment of the present application, not all of the embodiments. Based on the described embodiment of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0022] Unless otherwise defined, the technical terms or scientific terms used in this application should be understood by people with ordinary skills in the field to which this application belongs. "First", "second" and similar words used in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0023] In order to keep the following description of the embodiments of the present application clear and concise, the present application omits detailed descriptions of known functions and known components.

[0024] Figure 1 The schematic diagram of the structure of the waste heat utilization system of the alkali liquid electrolytic cell group provided in the embodiment of the present application is shown. Figure 1 As shown, the alkali solution electrolytic cell group waste heat utilization system of the present application includes:

[0025] At least two groups of electrolytic cell assemblies, each of which includes at least an electrolytic cell (not shown) and a correspondingly connected heat exchanger, each of which is provided with a coolant inlet and a coolant outlet;

[0026] A waste heat recycling pipe 200, wherein the waste heat recycling pipe 200 can be connected to each of the coolant inlets and each of the coolant outlets respectively;

[0027] When there is an electrolytic cell in a shutdown standby state, the waste heat recycling pipe 200 can obtain the heat of the electrolytic cell in a working state through a heat exchanger, and provide the obtained heat to the heat exchanger connected to the electrolytic cell in a shutdown standby state to heat the electrolytic cell in a shutdown standby state.

[0028] In the waste heat utilization system of the alkali liquid electrolyzer group of this embodiment, two or more electrolyzer assemblies can be configured according to actual production needs. Each electrolyzer assembly is equipped with an electrolyzer and a heat exchanger connected to the electrolyzer. In the present application, a large amount of heat is generated when the electrolyzer electrolyzes the alkali liquid. After the electrolysis of the solution after electrolysis is carried out for hydrogen and oxygen separation, the alkali liquid refluxed from the hydrogen and oxygen separator is cooled by the heat exchanger, and then enters the electrolyzer for electrolysis. The heat exchanger is provided with a coolant inlet and a coolant outlet, so that the received alkali liquid can be heat-exchanged by circulating the coolant to control the temperature of the alkali liquid entering the electrolyzer. The waste heat recycling pipe 200 can be connected to each of the coolant inlets and each of the coolant outlets according to actual needs, so as to obtain heat through the heat exchanger connected to the electrolyzer in the working state, and provide heat to the heat exchanger connected to the electrolyzer in the shutdown standby state. In some practical applications, the waste heat recovery pipe 200 can be made by setting pipe plugging plates at both ends of the pipe to form a closed pipe. Multiple pipe interfaces can be set on the closed pipe so that the waste heat recovery pipe 200 can be connected to the coolant inlet and coolant outlet of each heat exchanger through the pipe interface.

[0029] In some specific applications, two or more electrolytic cell assemblies can be divided into two types of electrolytic cell assemblies according to their respective working states. For the convenience of exemplary description, the electrolytic cell in the shutdown standby state is recorded as the first electrolytic cell (not shown), the electrolytic cell assembly in which it is located is recorded as the first electrolytic cell assembly 110, and the corresponding heat exchanger connected thereto is recorded as the first heat exchanger 112, which is provided with a first coolant inlet 1121 and a first coolant outlet 1122; the electrolytic cell in the working state is recorded as the second electrolytic cell (not shown), the electrolytic cell assembly in which it is located is recorded as the second electrolytic cell assembly 120, and the corresponding heat exchanger connected thereto is recorded as the second heat exchanger 122, which is provided with a second coolant inlet 1221 and a second coolant outlet 1222. In this way, when the alkali solution electrolytic cell grouping needs to reduce the number of working electrolytic cells, the electrolytic cell after shutdown (i.e., the first electrolytic cell) needs a hot standby machine so that it can be started at any time to enter the normal working state as needed. The first electrolytic cell in the shutdown standby state can be provided with heat by other second electrolytic cells in the working state to realize hot standby. At this time, the waste heat recycling pipe 200 can be controlled to be connected with the first cooling liquid inlet 1121 and the second cooling liquid outlet 1222 respectively, so that when the second heat exchanger 122 cools the high-temperature alkali solution generated by the electrolysis work of the second electrolytic cell, the waste heat recycling pipe 200 can be used to receive the heated cooling liquid from the second heat exchanger 122 through the second cooling liquid outlet 1222, and then the heated cooling liquid is provided to the first heat exchanger 112 through the first cooling liquid inlet 1121, so that the alkali solution is kept warm and preheated by the high-temperature circulating cooling liquid, and then the alkali solution after the insulation and preheating treatment is provided to the first electrolytic cell, so as to realize the purpose of hot standby of the first electrolytic cell, so that when the first electrolytic cell assembly 110 is enabled, the first electrolytic cell can directly enter the working state of electrolyzing the alkali solution, thereby improving the working efficiency.

[0030] The first electrolytic cell assembly 110 and the second electrolytic cell assembly 120 and corresponding components involved in the various embodiments of the present application are only used for exemplary description and are not intended to be limiting.

[0031] In the waste heat utilization system of the alkali liquid electrolytic cell group provided in the embodiment of the present application, by setting up the waste heat recycling pipe 200, the waste heat generated by the electrolytic cells in the working state can be transferred and utilized as needed, and the heat can be provided to the electrolytic cells that need hot standby for insulation and preheating, thereby improving the heat utilization efficiency and avoiding the need to add additional large equipment such as heat accumulators, thereby avoiding the problem of increased operating costs.

[0032] In some embodiments, the coolant inlet and the coolant outlet are respectively connected to a liquid inlet pipe and a liquid outlet pipe, and the other ends of the liquid inlet pipe and the liquid outlet pipe can be respectively connected to the waste heat recycling pipe 200 to form a waste heat supply branch 210 or a waste heat recovery branch 220 according to actual needs. In this embodiment, the first electrolytic cell assembly 110 and the second electrolytic cell assembly 120 are used as examples for explanation. Connecting pipes are respectively provided at the first coolant inlet 1121 and the first coolant outlet 1122 of the first heat exchanger 112 to construct a liquid inlet pipe 113 and a liquid outlet pipe 114 for the coolant to enter and discharge from the heat exchanger, and the other ends of the liquid inlet pipe 113 and the liquid outlet pipe 114 can be respectively connected to the waste heat recycling pipe 200 through pipes. Similarly, connecting pipes are respectively provided at the second coolant inlet 1221 and the second coolant outlet 1222 of the second heat exchanger 122, so as to construct a liquid inlet pipe 123 and a liquid outlet pipe 124 for the coolant to enter and discharge from the heat exchanger, and the other ends of the liquid inlet pipe 123 and the liquid outlet pipe 124 can be respectively connected to the waste heat recycling pipe 200 through pipes. When the liquid inlet pipe 113 and the liquid outlet pipe 124 are connected to the waste heat recycling pipe 200, the waste heat supply branch 210 between the first heat exchanger 112 and the waste heat recycling pipe 200 is connected, and is cut off from the coolant inlet main pipe 300, and the waste heat recovery branch 220 between the second heat exchanger 122 and the waste heat recycling pipe 200 is connected, and is cut off from the coolant return main pipe 400. In this way, the high-temperature coolant discharged from the second heat exchanger 122 can enter the waste heat recycling pipe 200 through the liquid outlet pipe 124 and the waste heat recovery branch 220, and the high-temperature coolant then enters the first heat exchanger 112 through the waste heat supply branch 210 and the liquid inlet pipe 113, so that the first heat exchanger 112 can use the waste heat generated during electrolysis in the second electrolytic cell for heat exchange, thereby realizing the hot standby of the first electrolytic cell in the shutdown standby state, so that the first electrolytic cell in the shutdown standby state can immediately enter the working state after startup.

[0033] In some embodiments, the waste heat utilization system of the alkali liquid electrolytic cell grouping further includes: a coolant inlet main pipe 300 and a coolant return main pipe 400, and the coolant inlet main pipe 300 and the coolant return main pipe 400 can be respectively connected to the inlet pipe and the outlet pipe to form a coolant supply pipeline 310 and a coolant recovery pipeline 410. In some specific applications of this embodiment, the waste heat utilization system of the alkali liquid electrolytic cell grouping further includes a coolant inlet main pipe 300 and a coolant return main pipe 400, which are used to provide coolant to the heat exchanger and discharge coolant. The heat exchangers of each electrolytic cell assembly are respectively connected to the coolant inlet main pipe 300 and the coolant return main pipe 400 through pipelines, so that coolant can be received from the coolant inlet main pipe 300 and enter each heat exchanger for heat exchange treatment, and the coolant after heat exchange treatment is discharged into the coolant return main pipe 400. Exemplarily, each electrolytic cell assembly in the waste heat utilization system of the alkali liquid electrolytic cell group is explained by taking the first electrolytic cell assembly 110 and the second electrolytic cell assembly 120 as an example. The liquid inlet pipe 113 and the liquid outlet pipe 114 of the first heat exchanger 112 are connected to the coolant inlet main pipe 300 and the coolant return main pipe 400 through pipes, and the liquid inlet pipe 123 and the liquid outlet pipe 124 of the second heat exchanger 122 are connected to the coolant inlet main pipe 300 and the coolant return main pipe 400 through pipes. If there are other electrolytic cell assemblies, they are connected in sequence to form a coolant supply pipeline 310 and a coolant recovery pipeline 410. In this way, when the first electrolytic cell and the second electrolytic cell are in working state and there is no need to provide waste heat for the hot standby electrolytic cell in the shutdown standby state, the coolant inlet main pipe 300 and the coolant return main pipe 400 can be connected to the inlet pipe 113 and the outlet pipe 114, as well as the inlet pipe 123 and the outlet pipe 124, respectively, so that the coolant supply pipeline 310 and the coolant recovery pipeline 410 corresponding to the first electrolytic cell and the second electrolytic cell are in a connected state, the first heat exchanger 112 and the second heat exchanger 122 can receive coolant from the coolant inlet main pipe 300 through the coolant supply pipeline 310, cool the alkaline solution produced by the first electrolytic cell and the second electrolytic cell in the working state, and can discharge the heated coolant to the coolant return main pipe 400 through the coolant recovery pipeline 410 to carry out subsequent treatment of the high-temperature coolant.

[0034] In some embodiments, the waste heat supply branch 210 is provided with a waste heat inlet switching valve 211, and the switching of the waste heat inlet switching valve 211 controls the corresponding heat exchanger to be connected to the waste heat recycling pipe 200 through the liquid inlet pipe. In other embodiments, the cooling liquid supply pipeline 310 is provided with a liquid inlet switching valve 311, and the switching of the liquid inlet switching valve 311 controls the corresponding heat exchanger to be connected to the cooling liquid inlet main pipe 300 through the liquid inlet pipe. In this way, in some practical applications, the switching of the waste heat inlet switching valve 211 and the liquid inlet switching valve 311 can be controlled according to the state of the electrolytic cell, and the waste heat supply branch 210 can be connected or closed by switching the waste heat inlet switching valve 211 to open or close; and the cooling liquid supply pipeline 311 can be connected or closed by switching the liquid inlet switching valve 311 to open or close. Thus, the coolant inlet of the heat exchanger can be connected to the waste heat recycling pipe 200 through the liquid inlet pipe to receive the heated coolant for insulation treatment; or connected to the coolant inlet main pipe 300 to receive coolant for cooling treatment.

[0035] In other embodiments, the waste heat recovery branch 220 is provided with a waste heat outlet switching valve 221, and the corresponding heat exchanger is controlled to be connected to the waste heat recycling pipe 200 through the liquid outlet pipeline by switching between the waste heat outlet switching valve 221 and the liquid outlet switching valve 411. In other embodiments, the coolant recovery pipeline 410 is provided with a liquid outlet switching valve 411, and the corresponding heat exchanger is controlled to be connected to the coolant return main pipe 300 through the liquid outlet pipeline by switching the liquid outlet switching valve 411. In this way, in some practical applications, the switching of the waste heat outlet switching valve 221 and the liquid outlet switching valve 411 can be controlled according to the state of the electrolytic cell, and the waste heat recovery branch is connected or closed by switching the waste heat outlet switching valve 221 to open or close; and the coolant recovery pipeline is connected or closed by switching the liquid outlet switching valve 411 to open or close. Thereby, the coolant outlet of the corresponding heat exchanger can be connected to the waste heat recycling pipe 200 through the liquid outlet pipe to recover the heated coolant for insulation of the electrolytic cell assembly in the shutdown standby state; or connected to the coolant return main pipe 400 to recover the discharged coolant.

[0036] Exemplarily, taking the waste heat utilization system of the alkali liquid electrolytic cell group including at least the first electrolytic cell assembly 110 and the second electrolytic cell assembly 120 as an example, the opening and closing states of each valve and the corresponding connected pipelines are explained. When the first electrolytic cell in the first electrolytic cell assembly 110 is in working state, the corresponding heat exchanger 112 needs to be used to cool the alkali liquid, then the waste heat inlet switching valve 211 corresponding to the first heat exchanger 112 can be controlled to close, the corresponding waste heat supply branch 210 can be closed, the corresponding liquid inlet switching valve 311 can be opened, and the corresponding coolant supply pipeline 310 can be connected. Therefore, the coolant inlet 1121 of the heat exchanger 112 can be connected to the coolant inlet main pipe 300 through the liquid inlet pipeline 113 and the coolant supply pipeline 310 to receive the coolant for cooling treatment. The first coolant outlet 1122 of the heat exchanger 112 can be connected to the waste heat recycling pipe 200 or the coolant return main pipe 400 through the liquid outlet pipe 114, depending on whether the waste heat generated by the electrolytic cell assembly 110 needs to be recovered in actual conditions.

[0037] If waste heat recovery is not required, the waste heat outlet switching valve 221 corresponding to the first heat exchanger 112 can be controlled to be closed, the corresponding waste heat recovery branch 220 can be closed, and the corresponding liquid outlet switching valve 411 can be controlled to be opened to connect the corresponding coolant recovery pipeline 410. Thus, the first coolant outlet 1122 of the first heat exchanger 112 can be connected to the coolant recovery pipeline 410 through the liquid outlet pipeline 114, and connected to the coolant return main pipe 400 to recover the discharged coolant.

[0038] If the second electrolytic cell in the second electrolytic cell assembly 120 is in a shutdown standby state and needs hot standby, the waste heat generated by the first electrolytic cell assembly 110 needs to be recovered. At this time, for the first electrolytic cell assembly 110, the liquid outlet switching valve 411 corresponding to the first heat exchanger 112 can be controlled to be closed, the corresponding coolant recovery pipeline 410 can be closed, and the corresponding waste heat outlet switching valve 221 can be controlled to be opened to connect the corresponding waste heat recovery branch 220. Thus, the first coolant outlet 1122 of the heat exchanger 112 can be connected to the waste heat recovery branch 220 through the liquid outlet pipeline 114, and connected to the waste heat recycling pipe 200, so as to recover the heated coolant discharged from the first heat exchanger 112 through the waste heat recycling pipe 200. For the second electrolytic cell assembly 120, the corresponding liquid inlet switching valve 311 is closed to close the corresponding coolant supply pipeline 311, and the waste heat inlet switching valve 211 corresponding to the second heat exchanger 122 is controlled to be opened to open the corresponding waste heat supply branch 210. Thus, the second coolant inlet 1221 of the second heat exchanger 122 can be connected to the waste heat supply branch 210 through the inlet pipe 123, and connected to the waste heat recycling pipe 200, so as to receive the heated coolant from the waste heat recycling pipe 200 for heat preservation treatment. The second coolant outlet 1222 of the heat exchanger 122 returns the coolant to the main pipe 400 through the outlet pipe, and specifically, the waste heat outlet switching valve 221 corresponding to the second heat exchanger 122 can be controlled to be closed, the corresponding waste heat recovery branch 220 is closed, and the corresponding outlet switching valve 411 is controlled to be opened, so as to connect the corresponding coolant recovery pipe 410. Thus, the second coolant outlet 1222 of the second heat exchanger 122 can be connected to the coolant return main pipe 400 through the outlet pipe 124 and the coolant recovery pipe 410, so as to recover the discharged coolant.

[0039] In some embodiments, a temperature regulating valve 312 is provided on the liquid inlet pipeline at the rear end of the coolant inlet main pipe 300, and the temperature regulating valve 312 is used to adjust the amount of coolant inlet when the coolant supply pipeline 310 is connected. In this embodiment, a temperature regulating valve 312 is provided on the liquid inlet pipeline of each electrolytic cell assembly, for example, a temperature regulating valve 312 is provided on the liquid inlet pipeline 123 and the liquid inlet pipeline 113, and the flow rate of the coolant provided to the heat exchanger can be adjusted by opening or closing the valve of the temperature regulating valve 312, so as to achieve the purpose of adjusting the temperature of the alkali solution entering the corresponding electrolytic cell through each heat exchanger.

[0040] In some embodiments, an alkali liquid inlet and an alkali liquid outlet are provided on both sides of the heat exchanger; the heat exchange channel in the heat exchanger guides the flow direction of the alkali liquid from the alkali liquid inlet to the alkali liquid outlet, which is inconsistent with the flow direction of the coolant from the coolant inlet to the coolant outlet. This embodiment aims to guide the flow direction of the alkali liquid to be different from the flow direction of the coolant, so as to obtain a larger heat transfer temperature difference and achieve sufficient heat exchange treatment of the alkali liquid. In some practical applications, the alkali liquid can be transmitted through the tube side of the heat exchanger, and the coolant is transmitted through the shell side of the heat exchanger. The following is an exemplary description in combination with the first electrolytic cell assembly 110 and the second electrolytic cell assembly 120. Figure 1 As shown in , the alkali liquid is introduced into the tube side of the heat exchanger from the alkali liquid inlet 1123 and is transferred from right to left to the alkali liquid outlet 1124 for discharge, or the alkali liquid is introduced into the tube side of the heat exchanger from the alkali liquid inlet 1223 and is transferred from right to left to the alkali liquid outlet 1224 for discharge, and the coolant is introduced into the shell side of the heat exchanger from the first coolant inlet 1121 and is transferred from left to right to the first coolant outlet 1122 for discharge, or the coolant is introduced into the shell side of the heat exchanger from the second coolant inlet 1221 and is transferred from left to right to the second coolant outlet 1222 for discharge, thereby forming a countercurrent heat exchange between the alkali liquid and the coolant, thereby improving the heat exchange efficiency.

[0041] In some embodiments, a thermometer is provided near the alkali liquid outlet, and the thermometer is used to measure the temperature of the alkali liquid flowing out of the heat exchanger. The alkali liquid needs to flow from the alkali liquid outlet of the heat exchanger to the electrolytic cell for electrolysis treatment. This embodiment aims to obtain the temperature of the alkali liquid flowing out of the heat exchanger. For the heat exchanger of each electrolytic cell assembly, a thermometer is provided on the alkali liquid transmission pipeline at the alkali liquid outlet. Taking the second electrolytic cell assembly 120 as an example, a thermometer 1224a is provided on the alkali liquid transmission pipeline at the alkali liquid outlet. The alkali liquid in the alkali liquid transmission pipeline is detected by the thermometer 1224a. When it is determined that the alkali liquid temperature is too high or too low and does not meet the technical requirements, the valve of the temperature regulating valve 312 can be controlled by the automatic control instrument to adjust the flow rate of the coolant to increase or decrease, so that the temperature of the alkali liquid refluxed to the second electrolytic cell can be maintained at a constant temperature value as required.

[0042] In some embodiments, the electrolyzer assembly further includes a hydrogen separator (not shown) and an oxygen separator (not shown), and the hydrogen separator and the oxygen separator are respectively connected to the outlet of the electrolyzer; the hydrogen separator and the oxygen separator are both provided with a liquid outlet (not shown), and each of the liquid outlets is connected to the alkali solution inlet. In this embodiment, taking the second electrolyzer assembly as an example, after the alkali solution is electrolyzed by the second electrolyzer, the temperature of the alkali solution rises and hydrogen and oxygen are collected respectively by the hydrogen separator and the oxygen separator. The hot alkali solution refluxed from the hydrogen separator and the oxygen separator enters the heat exchanger through the alkali solution inlet 1223, and countercurrent heat exchange with the coolant is performed for cooling treatment. In some practical applications, the hot alkali solution refluxed from the hydrogen separator and the oxygen separator is about 90°, the coolant can be circulating water less than 32°, and the alkali solution is cooled to about 65° and sent to the second electrolyzer for the next electrolysis. Taking the case where the electrolytic cell in the first electrolytic cell assembly is in a shutdown standby state as an example, the first electrolytic cell does not perform electrolysis and does not generate heat. When the alkali solution passes through the corresponding heat exchanger, since the heat exchanger receives the heated coolant from the waste heat heat exchange tube, the alkali solution can be preheated and kept warm through heat exchange with the coolant, so that the hydrogen separator and the oxygen separator can also maintain the corresponding temperature through the circulation of the alkali solution, so that after the first electrolytic cell is started, the hydrogen separator and the oxygen separator can enter the working state synchronously to improve work efficiency.

[0043] In some embodiments, the electrolytic cell assembly further includes an alkali liquid circulation pump (not shown), one end of the alkali liquid circulation pump being connected to the alkali liquid inlet 1123 and the alkali liquid inlet 1223, and the other end being connected to each of the liquid outlets, so as to transfer the alkali liquid to the first heat exchanger 112 and the second heat exchanger 122 through the alkali liquid circulation pumps in different electrolytic cell assemblies to cool the hot alkali liquid, and then the alkali liquid cooled to a suitable temperature is sent to the first electrolytic cell and the second electrolytic cell for the next decomposition and hydrogen and oxygen separation cycle.

[0044] In some practical applications of this embodiment, by setting a waste heat recycling pipe, the waste heat generated by the working electrolytic cell can be transferred and utilized as needed, and the heat can be provided to the heat exchanger corresponding to the electrolytic cell in the shutdown standby state to keep the alkali solution warm. For the electrolytic cell in the working state, the hot alkali solution of about 90°C refluxed from the hydrogen-oxygen separator enters the heat exchanger and countercurrently exchanges heat with the coolant below 32°C. The alkali solution is cooled to about 65°C and sent to the lower part of the connected alkaline electrolytic cell. When the workload of the electrolytic cell in the working state decreases, the temperature of the reflux alkali solution decreases, and the alkali solution temperature regulating valve of the liquid inlet pipeline corresponding to the connected heat exchanger is closed by the automatic control instrument to reduce the flow of the coolant; otherwise, the alkali solution temperature regulating valve is opened to increase the flow of the coolant, so that the temperature of the alkali solution at the alkali solution outlet of the heat exchanger is constant at 65°C. Because the temperature of the coolant leaving the heat exchanger is close to the temperature of the hot alkali solution during the countercurrent heat exchange process of the heat exchanger, the temperature of the coolant outlet of the heat exchanger is about 80°C after removing the 10°C temperature difference caused by the heat resistance of the heat exchanger. For the electrolytic cells that need to be hot-standby in the shutdown standby state, their alkali solution circulation pumps continue to run to maintain the circulation of alkali solution between the electrolytic cells and the heat exchanger. The heat exchanger connected to the electrolytic cells in the shutdown hot standby state receives coolant at a temperature of about 80°C through the waste heat recycling pipe 200. The coolant can heat the alkali solution to 70°C as a heating medium. Then, through the circulation of the alkali solution, the corresponding electrolytic cells can be insulated and preheated, so that the electrolytic cells can enter normal electrolysis after startup without waiting for the alkali solution to heat up to the rated temperature.

[0045] In addition, although exemplary embodiments have been described herein, the scope includes any and all embodiments based on the present application with equivalent elements, modifications, omissions, combinations (e.g., various embodiments intersecting schemes), adaptations or changes. The elements in the claims will be interpreted broadly based on the language adopted in the claims, and are not limited to the examples described in this specification or during the implementation of the application, and the examples will be interpreted as non-exclusive. Therefore, this specification and examples are intended to be considered as examples only, and the true scope and spirit are indicated by the following claims and the full scope of their equivalents.

[0046] The above description is intended to be illustrative rather than restrictive. For example, the above examples (or one or more of them) can be used in combination with each other. For example, those of ordinary skill in the art can use other embodiments when reading the above description. In addition, in the above-mentioned specific embodiments, various features can be grouped together to simplify the application. This should not be interpreted as an intention that a disclosed feature that does not require protection is necessary for any claim. On the contrary, the subject matter of the present application may be less than all the features of a specific disclosed embodiment. Thus, the following claims are incorporated into the specific embodiments as examples or embodiments, wherein each claim is independently used as a separate embodiment, and it is considered that these embodiments can be combined with each other in various combinations or arrangements. The scope of the present application should be determined with reference to the attached claims and the full scope of equivalent forms granted by these claims.

[0047] Multiple embodiments of the present application are described in detail above, but the present application is not limited to these specific embodiments. Those skilled in the art can make various variations and modifications to the embodiments based on the concept of the present application, and these variations and modifications should all fall within the scope of protection required by the present application.

Claims

1. A waste heat utilization system for an alkali solution electrolytic cell group, wherein: include: At least two groups of electrolytic cell assemblies, each of which comprises at least an electrolytic cell and a correspondingly connected heat exchanger, each of which is provided with a coolant inlet and a coolant outlet; A waste heat recycling pipe, wherein the waste heat recycling pipe can be connected to each of the coolant inlets and each of the coolant outlets respectively; When there is an electrolytic cell in a shutdown standby state, the waste heat recycling pipe can obtain the heat of the electrolytic cell in a working state through a heat exchanger, and provide the obtained heat to the heat exchanger connected to the electrolytic cell in a shutdown standby state to heat the electrolytic cell in a shutdown standby state.

2. The waste heat utilization system of alkali solution electrolytic cells according to claim 1, wherein: The coolant inlet and the coolant outlet are respectively connected to a liquid inlet pipe and a liquid outlet pipe, and the other ends of the liquid inlet pipe and the liquid outlet pipe can be respectively connected to the waste heat recycling pipe to form a waste heat supply branch or a waste heat recovery branch.

3. The waste heat utilization system of alkali solution electrolytic cells according to claim 2, wherein: The waste heat supply branch is provided with a waste heat inlet switching valve, and the waste heat recovery branch is provided with a waste heat outlet switching valve.

4. The waste heat utilization system of alkali solution electrolytic cells according to claim 2, wherein: Also includes: The coolant inlet main pipe and the coolant return main pipe can be connected to the inlet pipe and the outlet pipe respectively to form a coolant supply pipeline and a coolant recovery pipeline.

5. The waste heat utilization system of alkali solution electrolytic cell grouping according to claim 4, wherein: The coolant supply pipeline and the coolant recovery pipeline are respectively provided with a liquid inlet switching valve and a liquid outlet switching valve.

6. The waste heat utilization system of alkali solution electrolytic cells according to claim 5, wherein: A temperature regulating valve is provided on the liquid inlet pipeline at the rear end of the coolant inlet main pipe, and the temperature regulating valve is used to adjust the inlet amount of the coolant when the coolant pipeline is connected.

7. The waste heat utilization system of alkali liquid electrolytic cell grouping according to any one of claims 1 to 6, wherein: An alkali liquid inlet and an alkali liquid outlet are provided on both sides of the heat exchanger; the flow direction of the alkali liquid guided by the heat exchange channel in the heat exchanger from the alkali liquid inlet to the alkali liquid outlet is inconsistent with the flow direction of the coolant guided from the coolant inlet to the coolant outlet.

8. The waste heat utilization system of alkali solution electrolytic cells according to claim 7, wherein: A thermometer is provided near the alkali solution outlet, and the thermometer is used to measure the temperature of the alkali solution flowing out of the heat exchanger.

9. The waste heat utilization system of alkali solution electrolytic cells according to claim 8, wherein: The electrolytic cell assembly also includes a hydrogen separator and an oxygen separator, which are respectively connected to the outlet of the electrolytic cell; the hydrogen separator and the oxygen separator are both provided with a liquid outlet, and each of the liquid outlets is connected to the alkali solution inlet.

10. The waste heat utilization system of alkali solution electrolytic cells according to claim 9, wherein: The electrolytic cell assembly also includes an alkali solution circulation pump, one end of which is connected to the alkali solution inlet, and the other end of which is connected to each of the liquid outlets.

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