Multi-group electrolytic cell fluctuation working condition energy management and waste heat recovery system and control method thereof

Abstract

The invention discloses a multi-group electrolytic bath fluctuation working condition energy management and waste heat recovery system and a control method thereof. The system comprises a plurality of groups of electrolytic baths (1), a gas-liquid separation device (2), a hydrogen collection device (3), a seawater cooling device (4), a waste heat recovery device (5) and process equipment (6). According to the system disclosed by the invention, a plurality of groups of electrolytic cells share a gas-liquid separation device, and electrolyte of the gas-liquid separation device (2) is separately cooled by a plurality of cooling units in an electrolyte seawater cooling part (8). And the temperature and flow of the electrolyte flowing back to the inlet of each electrolytic cell are accurately controlled, so that the electrolysis system is in a high-energy-efficiency working condition when faced with a fluctuating working condition.

Description

Technical Field

[0001] The present invention relates to the fields of hydrogen production by electrolysis of seawater, gas-liquid separation devices and waste heat recovery devices, and in particular to a fluctuating operating condition energy management and waste heat recovery system for multiple groups of electrolytic cells and a control method thereof. Background Art

[0002] As a zero-CO2 emission energy conversion method, water electrolysis hydrogen production technology has become an important part of new energy development due to its clean, efficient and sustainable characteristics.

[0003] Hydrogen production by water electrolysis is a process of converting electrical energy into hydrogen energy by decomposing water into hydrogen and oxygen through electrolysis. This technology has the advantages of being environmentally friendly, efficient, and easy to control, and is one of the important methods for producing hydrogen. Since the process of hydrogen production by water electrolysis does not produce any greenhouse gases, it is considered to be a green hydrogen production technology with great potential.

[0004] Using excess renewable energy (such as solar energy, wind energy, etc.) to electrolyze water to produce hydrogen, converting electrical energy into hydrogen for storage, can not only effectively absorb the surplus of new energy electricity, but also provide stable energy security and power supply when energy demand peaks or new energy supply is insufficient. This "electricity-hydrogen-electricity" energy conversion method provides a new solution for optimizing energy structure and ensuring energy security.

[0005] Although water electrolysis hydrogen production technology has many advantages, it still faces some challenges in practical application. Especially in the process of offshore renewable energy power generation, due to the intermittent and volatile nature of renewable energy, the fluctuating load has a significant impact on the energy utilization efficiency and system operation stability of the electrolysis system. This may not only lead to a decrease in electrolysis efficiency, but also damage the electrolysis equipment and reduce the service life of the system.

[0006] In order to solve the operational stability problem of the electrolytic water hydrogen production system under the fluctuation of offshore new energy, it is necessary to develop a water electrolytic water hydrogen production system that can adapt to the fluctuation of new energy and operate efficiently and stably, which is of great significance for promoting the widespread application of water electrolytic water hydrogen production technology and the development of new energy. This patent is proposed in this context, aiming to solve the above problems and provide new solutions for the further development of water electrolytic water hydrogen production technology. Summary of the invention

[0007] The present invention provides a system for energy management and waste heat recovery of multiple groups of electrolytic cells under fluctuating working conditions. The whole system consists of multiple groups of electrolytic cells, a gas-liquid separation device, a seawater cooling device, process equipment, hydrogen collection, and waste heat recovery devices. The electrolytes of multiple groups of electrolytic cells are connected to the same pipeline and then connected to the gas-liquid separation device. The electrolytes passing through the gas-liquid separation device enter the seawater cooling device after adjusting the flow rate in sections, and are cooled separately by the electrolyte seawater cooling part, and the outlet temperature of each cooling device is controlled to flow back to each electrolytic cell. The hydrogen separated by the gas-liquid separation device is cooled by the cooling part, and then enters the hydrogen collection device to be sent out as product hydrogen. The cooling water of the process equipment is cooled by seawater. The cooling seawater flows out of the waste heat recovery device and enters the seawater cooling device. The refluxed hot seawater after heat exchange includes the gas cooling part cooling seawater, the electrolyte seawater cooling part cooling seawater, and the process equipment cooling seawater. The hot seawater enters the waste heat recovery device for flash evaporation recovery to obtain steam. After obtaining the steam, the water in the evaporator is connected to the seawater cooling device as cooling seawater for re-heat exchange.

[0008] The working principle of the present invention is as follows:

[0009] The present invention provides a fluctuating working condition energy management and waste heat recovery system for multiple groups of electrolytic cells. Through waste heat recovery of low-grade heat sources in gas-liquid separation processes and other process equipment, combined with temperature control strategies, the temperature of reflux alkali solution is controlled for electrolytic cells with different loads, so as to achieve efficient utilization of system energy and maintain good working conditions of electrolytic cells with different loads. Multiple groups of electrolytic cell outlets are connected in parallel and input into a gas-liquid separation device together. After separation, seawater is used to cool the electrolyte, hydrogen and other process equipment. Under different working conditions, the gas-liquid separation device adjusts the flow rate of each electrolyte. According to the load requirements of different electrolytic cells, the flow rate of seawater is controlled by a valve to control the temperature of the electrolyte after heat exchange, so as to ensure that the electrolytic cell operates under good working conditions and that the outlet temperature of each electrolytic cell is consistent before entering the gas-liquid separation device for operation. Hydrogen is output to a collection device after being cooled by seawater. After the cooling seawater exchanges heat with the hot fluid in each part, it is output to the waste heat utilization device for waste heat recovery. In the waste heat recovery device, the hot seawater is flash-steamed, and the heat is converted into the latent heat of vaporization of steam. It is cooled by the normal-temperature seawater in the environment, and the normal-temperature seawater is discharged into the environment after heat exchange with the steam.

[0010] The present invention is achieved through the following technical solutions:

[0011] A first aspect of the present invention provides a system for energy management and waste heat recovery of multiple groups of electrolytic cells under fluctuating conditions, the system comprising multiple groups of electrolytic cells 1, a gas-liquid separation device 2, a hydrogen collection device 3, a seawater cooling device 4, a waste heat recovery device 5, and a process equipment 6;

[0012] The electrolytes in the multiple groups of electrolytic cells 1 are connected to the same pipeline and then connected to the gas-liquid separation device 2;

[0013] The electrolyte that has passed through the gas-liquid separation device 2 enters the seawater cooling device 4, and after being cooled, flows back to each electrolytic cell in the multiple groups of electrolytic cells 1;

[0014] The hydrogen separated by the gas-liquid separation device 2 enters the seawater cooling device 4, and after being cooled, enters the hydrogen collection device 3 to be sent out as product hydrogen;

[0015] The seawater flows out after passing through the waste heat recovery device 5, and then enters the seawater cooling device 4 as cooling seawater to cool the process equipment 6 and the electrolyte and hydrogen transported by the gas-liquid separation device 2. The refluxed hot seawater after heat exchange enters the waste heat recovery device 5 for flash evaporation recovery to obtain steam. After obtaining the steam, the water in the evaporator is connected to the seawater cooling device 4 as cooling seawater for re-heat exchange.

[0016] Preferably, the refluxed hot seawater includes the hot seawater for gas cooling, the hot seawater for electrolyte cooling, and the hot seawater for process equipment cooling.

[0017] Preferably, the seawater cooling device 4 includes a gas cooling part cooling 7 and an electrolyte seawater cooling part 8, the hydrogen separated by the gas-liquid separation device 2 enters the gas cooling part cooling 7 in the seawater cooling device 4 for cooling, and the electrolyte passing through the gas-liquid separation device 2 enters the electrolyte seawater cooling part 8 in the seawater cooling device 4 for cooling.

[0018] Preferably, the electrolyte seawater cooling part 8 includes multiple cooling units, the electrolyte passing through the gas-liquid separation device 2 enters the seawater cooling device 4, and is separately cooled by the multiple cooling units in the electrolyte seawater cooling part 8, and the electrolyte separately cooled by the multiple cooling units flows back to the multiple electrolytic cells in the multiple groups of electrolytic cells 1.

[0019] The second aspect of the present invention provides a control method for the energy management and waste heat recovery system of multiple groups of electrolytic cells under fluctuating working conditions as described in the first aspect of the present invention, which comprises: when the working conditions of the electrolytic cells fluctuate, the gas-liquid separation device 2 adjusts the electrolyte flow rate of each cooling unit in the electrolyte seawater cooling part 8 in the seawater cooling device 4, thereby controlling the electrolyte circulation flow rate refluxed to each electrolytic cell. The electrolyte passing through the gas-liquid separation device 2 enters the seawater cooling device 4 after adjusting the segmented control flow rate, and is cooled separately by multiple cooling units in the electrolyte seawater cooling part 8.

[0020] Preferably, when the working condition of the electrolytic cell fluctuates, the flow rate of seawater entering each cooling unit is controlled to control the temperature of the electrolyte at the outlet of each cooling unit, thereby controlling the temperature of the electrolyte in each electrolytic cell in the multiple groups of electrolytic cells 1. According to the load conditions of different electrolytic cells, the seawater flow rate is regulated by the valve opening to adjust the temperature of the cooled alkali solution, so that the alkali solution that flows back can maintain the good operation of electrolytic cells with different loads.

[0021] Preferably, when the operating conditions of the electrolyzer fluctuate, the waste heat recovery device 5 adjusts the amount of cooling normal temperature seawater according to the total load. When the total load increases, the flow rate of normal temperature seawater is increased; when the total load decreases, the flow rate of normal temperature seawater is reduced.

[0022] Compared with the existing technology, the present invention has the following beneficial effects:

[0023] 1. The system of the present invention uses a gas-liquid separation device shared by multiple groups of electrolytic cells, and the electrolyte of the gas-liquid separation device 2 is cooled separately by multiple cooling units in the electrolyte seawater cooling part 8. The present invention controls the electrolyte flow rate and seawater flow rate of each cooling unit to accurately control the electrolyte temperature and flow rate returning to the inlet of each electrolytic cell, so as to keep the electrolysis system in a high energy efficiency state when facing fluctuating working conditions.

[0024] Specifically, the electrolyte seawater cooling part 8 of the system of the present invention includes a plurality of cooling units, and the electrolyte passing through the gas-liquid separation device 2 enters the seawater cooling device 4, and is separately cooled by the plurality of cooling units in the electrolyte seawater cooling part 8, and the electrolyte separately cooled by the plurality of cooling units is then refluxed to the plurality of electrolytic cells in the plurality of groups of electrolytic cells 1. When the operating conditions of the electrolytic cells fluctuate, the gas-liquid separation device 2 adjusts the electrolyte flow rate of each cooling unit in the electrolyte seawater cooling part 8 in the seawater cooling device 4, thereby controlling the electrolyte circulation flow rate refluxed to each electrolytic cell.

[0025] Because the electrolyte is cooled separately, when the working condition of the electrolyzer fluctuates, the electrolyte temperature at the outlet of each cooling unit is controlled by controlling the flow of seawater entering each cooling unit, thereby controlling the electrolyte temperature in each electrolyzer in the multiple groups of electrolyzers 1, so that the alkali solution that flows back separately can maintain the good operation of electrolyzers with different loads. The outlet temperature of the electrolyzer remains consistent, so that the electrolysis system is in a high-efficiency working condition, and at the same time has good fluctuating working condition adjustment capabilities.

[0026] When the operating conditions of the electrolytic cell fluctuate, the waste heat recovery device 5 adjusts the amount of cooling seawater according to the total load. When the total load increases, the flow rate of the seawater is increased; when the total load decreases, the flow rate of the seawater is reduced.

[0027] 2. The system of the present invention fully recovers the cooling waste heat of all devices in the system, avoids the use of cooling towers and reverse osmosis water treatment devices, reduces the number of equipment in the overall seawater electrolysis hydrogen production process, has high equipment integration, small footprint, simple waste heat recovery control logic, and improves the overall energy utilization efficiency of the system.

[0028] 3. The present invention couples the electrolytic cooling system with the waste heat recovery system, and combines the temperature control strategy with the fluctuating operating conditions to accurately control the inlet temperature and flow rate of multiple groups of electrolytic cells, efficiently recover and utilize low-grade waste heat energy, and improve the energy utilization rate of the system.

[0029] 4. The present invention proposes a fluctuating operating condition energy management and waste heat recovery system for multiple groups of electrolytic cells, which utilizes seawater to cool the water electrolysis hydrogen production system, and simultaneously uses a waste heat recovery system to recover the heat, and utilizes waste heat flash evaporation-cooling to obtain condensed water for electrolysis system water replenishment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the structure of the energy management and waste heat recovery system for multiple groups of electrolytic cells under fluctuating working conditions of the present invention;

[0031] Figure 2 , Figure 3 , Figure 4 All of them are logical schematic diagrams of the control strategy of the system of the present invention.

[0032] The names of the figure numbers in the figure description: 1. Multiple groups of electrolytic hydrogen production electrolyzers, 2. Gas-liquid separation device, 3. Hydrogen purification and collection device, 4. Seawater cooling device, 5. Waste heat recovery device, 6. Process equipment, 7. Gas cooling part, 8. Electrolyte seawater cooling part. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with embodiments.

[0034] Those skilled in the art will appreciate 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 art or the product specifications are used. If the manufacturer of the materials or equipment used is not specified, they are all conventional products that can be purchased.

[0035] 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 invention 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 herein may include wireless connections.

[0036] 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.

[0037] 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.

[0038] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as those generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as herein.

[0039] Example

[0040] The energy management and waste heat recovery system for multiple groups of electrolytic cells under fluctuating conditions in this embodiment includes multiple groups of electrolytic cells 1, a gas-liquid separation device 2, a hydrogen collection device 3, a seawater cooling device 4, a waste heat recovery device 5, and a process equipment 6;

[0041] The electrolytes in the multiple groups of electrolytic cells 1 are connected to the same pipeline and then connected to the gas-liquid separation device 2;

[0042] The electrolyte that has passed through the gas-liquid separation device 2 enters the seawater cooling device 4, and after being cooled, flows back to each electrolytic cell in the multiple groups of electrolytic cells 1;

[0043] The hydrogen separated by the gas-liquid separation device 2 enters the seawater cooling device 4, and after being cooled, enters the hydrogen collection device 3 to be sent out as product hydrogen;

[0044] The seawater flows out after passing through the waste heat recovery device 5, and then enters the seawater cooling device 4 as cooling seawater to cool the process equipment 6 and the electrolyte and hydrogen transported by the gas-liquid separation device 2. The refluxed hot seawater after heat exchange enters the waste heat recovery device 5 for flash evaporation recovery to obtain steam. After obtaining the steam, the water in the evaporator is connected to the seawater cooling device 4 as cooling seawater for re-heat exchange.

[0045] The refluxed hot seawater includes the hot seawater for gas cooling, the hot seawater for electrolyte cooling, and the hot seawater for process equipment cooling.

[0046] The seawater cooling device 4 includes a gas cooling part cooling 7 and an electrolyte seawater cooling part 8. The hydrogen separated by the gas-liquid separation device 2 enters the gas cooling part cooling 7 in the seawater cooling device 4 for cooling, and the electrolyte passing through the gas-liquid separation device 2 enters the electrolyte seawater cooling part 8 in the seawater cooling device 4 for cooling.

[0047] The electrolyte seawater cooling part 8 includes multiple cooling units. The electrolyte passing through the gas-liquid separation device 2 enters the seawater cooling device 4 and is separately cooled by the multiple cooling units in the electrolyte seawater cooling part 8. The electrolyte separately cooled by the multiple cooling units then flows back to the multiple electrolytic cells in the multiple groups of electrolytic cells 1.

[0048] In the control method of the energy management and waste heat recovery system for multiple groups of electrolytic cells under fluctuating working conditions described in this embodiment, when the working conditions of the electrolytic cells fluctuate, the gas-liquid separation device 2 adjusts the electrolyte flow rate of each cooling unit in the electrolyte seawater cooling part 8 in the seawater cooling device 4, thereby controlling the electrolyte circulation flow rate refluxed to each electrolytic cell. The electrolyte passing through the gas-liquid separation device 2 enters the seawater cooling device 4 after adjusting the segmented control flow rate, and is cooled separately by multiple cooling units in the electrolyte seawater cooling part 8.

[0049] When the working condition of the electrolytic cell fluctuates, the flow rate of seawater entering each cooling unit is controlled to control the temperature of the electrolyte at the outlet of each cooling unit, thereby controlling the temperature of the electrolyte in each electrolytic cell in the multiple groups of electrolytic cells 1. According to the load conditions of different electrolytic cells, the seawater flow rate is regulated by the valve opening to adjust the temperature of the cooled alkali solution, so that the alkali solution that flows back can maintain the good operation of the electrolytic cells with different loads.

[0050] When the operating conditions of the electrolytic cell fluctuate, the waste heat recovery device 5 adjusts the amount of cooling seawater according to the total load. When the total load increases, the flow rate of the seawater is increased; when the total load decreases, the flow rate of the seawater is reduced.

[0051] Combine the following Figure 1 , Figure 2 , Figure 3 , Figure 4 A specific implementation scheme is proposed to the present invention:

[0052] Taking three groups of electrolyzers as an example, three groups of electrolyzers are arranged in the multi-group electrolytic hydrogen production electrolyzer 1, which are connected to the gas-liquid separation device 2, the electrolyte liquid is connected to the electrolyte seawater cooling part 8 in the seawater cooling device 4, the gas enters the gas cooling part 7 for cooling, and the cooling water of the operating process equipment 6 is connected to the seawater cooling device 4. The electrolyte with controlled temperature after cooling is returned to the multi-group electrolytic hydrogen production electrolyzer 1 for electrolysis. The heated seawater after heat exchange in the seawater cooling device 4 is connected to the waste heat recovery device 5, and the seawater after heat energy recovery in the waste heat recovery device 5 is connected to the seawater cooling device 4 as cooling seawater for re-heat exchange. The ambient seawater is connected to the waste heat recovery device 5 for heat exchange and discharged to the environment after heating.

[0053] Combination Figure 1 , Figure 2 and Figure 3The working principle of the device of the present invention is explained as follows: the outlets of multiple groups of electrolytic hydrogen production electrolyzers 1 with different loads are connected together to the gas-liquid separation device 2. The separated hydrogen, electrolyte and process equipment 6 are cooled by seawater respectively. After being cooled by seawater, the hydrogen enters 3. The hydrogen collection device, and the electrolyte adjusts the temperature of the cooled alkali solution by regulating the seawater flow rate according to the load conditions of different electrolyzers by the valve opening, so that the refluxed alkali solution can maintain the good operation of electrolyzers with different loads. When the working conditions of the electrolyzer fluctuate, the gas-liquid separation device 2 adjusts the electrolyte circulation flow required by each electrolyzer, and enters the electrolyte seawater cooling part 8 in the seawater cooling device 4. Some parts are equipped with separate seawater coolers to ensure that the outlet temperature of the electrolyzer is consistent so that each electrolyzer is in an efficient operating state, and the seawater cooling heat exchanger 1, the seawater cooling heat exchanger 2, and the seawater cooling heat exchanger 3 are cooled and the temperature is adjusted respectively. The outlet temperature of the electrolytic cell 1 of the multi-group hydrogen production by electrolysis is set to 85°C. When the outlet temperature of the electrolytic cell 1 is higher than 85°C, the seawater cooling heat exchanger 1 is adjusted to reduce the outlet temperature of the electrolytic cell 1. When the outlet temperature of the electrolytic cell 1 is lower than 84°C, the seawater cooling heat exchanger 1 is adjusted to increase the outlet temperature of the electrolytic cell 1. When the outlet temperature of the electrolytic cell 2 is higher than 85°C, the seawater cooling heat exchanger 2 is adjusted to reduce the outlet temperature of the electrolytic cell 2. When the outlet temperature of the electrolytic cell 2 is lower than 84°C, the seawater cooling heat exchanger 2 is adjusted to increase the outlet temperature of the electrolytic cell 2. When the outlet temperature of the electrolytic cell 3 is higher than 85°C, the seawater cooling heat exchanger 3 is adjusted to reduce the outlet temperature of the electrolytic cell 2. When the outlet temperature of the electrolytic cell 3 is lower than 84°C, the seawater cooling heat exchanger 3 is adjusted to increase the outlet temperature of the electrolytic cell 3. For any heat exchange device among the seawater cooling heat exchanger 1, the seawater cooling heat exchanger 2, and the seawater cooling heat exchanger 3 provided in the electrolyte seawater cooling part 8, the flow rate I s Circulating seawater, the regulated seawater flow is I i When T2 is greater than 85℃, the valve opening is adjusted to increase the seawater flow rate I i When T2 is less than 84℃, adjust the valve opening to reduce the seawater flow rate I i , so that the temperature of the electrolyte entering the electrolytic cell and the outlet temperature of the electrolysis are maintained at 85℃ after cooling.

[0054] The seawater after heat exchange with hydrogen, alkali solution and process equipment enters the waste heat recovery device 8, and the seawater after effective use of heat is discharged into the environment. When the working conditions change, the waste heat recovery device 8 adjusts the amount of cooling normal temperature seawater according to the total load. When the total load increases, the flow rate of normal temperature seawater is increased; when the total load decreases, the flow rate of normal temperature seawater is reduced.

Claims

1. A system for energy management and waste heat recovery of multiple groups of electrolytic cells under fluctuating conditions, characterized in that: The system comprises a plurality of electrolytic cells (1), a gas-liquid separation device (2), a hydrogen collection device (3), a seawater cooling device (4), a waste heat recovery device (5), and process equipment (6); The electrolytes in the multiple groups of electrolytic cells (1) are connected to the same pipeline and then connected to the gas-liquid separation device (2); The electrolyte that has passed through the gas-liquid separation device (2) enters the seawater cooling device (4), and after being cooled, flows back to each electrolytic cell in the plurality of groups of electrolytic cells (1); The hydrogen separated by the gas-liquid separation device (2) enters the seawater cooling device (4), and after being cooled, enters the hydrogen collection device (3) to be sent out as product hydrogen; The seawater flows out after passing through the waste heat recovery device (5), and then enters the seawater cooling device (4) as cooling seawater to cool the process equipment (6) and the electrolyte and hydrogen transported by the gas-liquid separation device (2). The refluxed hot seawater after heat exchange enters the waste heat recovery device (5) for flash evaporation to obtain steam. After obtaining the steam, the water in the evaporator is used as cooling seawater and connected to the seawater cooling device (4) for re-heat exchange.

2. The system according to claim 1, characterized in that The refluxed hot seawater includes the hot seawater for gas cooling, the hot seawater for electrolyte cooling, and the hot seawater for process equipment cooling.

3. The system according to claim 1, characterized in that The seawater cooling device (4) comprises a gas cooling part (7) and an electrolyte seawater cooling part (8). The hydrogen separated by the gas-liquid separation device (2) enters the gas cooling part (7) in the seawater cooling device (4) for cooling, and the electrolyte passing through the gas-liquid separation device (2) enters the electrolyte seawater cooling part (8) in the seawater cooling device (4) for cooling.

4. The system according to claim 1, characterized in that The electrolyte seawater cooling part (8) comprises a plurality of cooling units. The electrolyte passing through the gas-liquid separation device (2) enters the seawater cooling device (4) and is separately cooled by the plurality of cooling units in the electrolyte seawater cooling part (8). The electrolyte separately cooled by the plurality of cooling units then flows back to the plurality of electrolytic cells in the plurality of groups of electrolytic cells (1).

5. A control method for a system for managing energy and recovering waste heat under fluctuating conditions of multiple electrolytic cells according to any one of claims 1 to 4, characterized in that: It includes: When the operating conditions of the electrolytic cell fluctuate, the gas-liquid separation device (2) adjusts the electrolyte flow rate of each cooling unit in the electrolyte seawater cooling part (8) in the seawater cooling device (4), thereby controlling the electrolyte circulation flow rate returning to each electrolytic cell.

6. The control method according to claim 5, characterized in that: When the operating conditions of the electrolytic cells fluctuate, the flow rate of seawater entering each cooling unit is controlled to control the temperature of the electrolyte at the outlet of each cooling unit, thereby controlling the temperature of the electrolyte in each electrolytic cell in the plurality of groups of electrolytic cells (1).

7. The control method according to claim 5, characterized in that: When the operating conditions of the electrolytic cell fluctuate, the waste heat recovery device (5) adjusts the amount of cooling normal temperature seawater according to the total load. When the total load increases, the flow rate of normal temperature seawater is increased; when the total load decreases, the flow rate of normal temperature seawater is reduced.

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