Series-parallel electrolysis system and series-parallel electrolysis method

Abstract

The invention relates to the technical field of hydrogen production, in particular to a series-parallel electrolysis system and a series-parallel electrolysis method.The series-parallel electrolysis system comprises a PEM electrolysis device which comprises a PEM electrolytic bath, a first hydrogen separator, a first oxygen separator, a pure water cooler and a pure water circulating pump; the alkaline electrolysis device comprises an alkaline electrolytic bath, a second hydrogen separator, a second oxygen separator, an alkaline liquor cooler and an alkaline liquor circulating pump; in the PEM electrolysis device, the heat exchanger is connected between the pure water cooler and the pure water circulating pump, in the alkaline electrolysis device, the heat exchanger is connected between the alkaline liquid cooler and the alkaline liquid circulating pump, and the pure water of the PEM electrolysis device and the alkaline liquid of the alkaline electrolysis device are subjected to heat exchange in the heat exchanger. According to the scheme, the defect that cost effectiveness and power adaptability are difficult to consider at the same time in the prior art is overcome, and efficient and economical green hydrogen production is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production, and in particular to a hybrid electrolysis system and a hybrid electrolysis method. Background Art

[0002] As the global demand for clean energy continues to grow, hydrogen has attracted widespread attention as an efficient energy carrier. Among them, the production of green hydrogen is achieved through the electrolysis of water driven by renewable energy, which is not only environmentally friendly but also sustainable. As an indispensable core equipment in this process, the performance of the hydrogen production electrolyzer directly determines the efficiency and cost of hydrogen production.

[0003] Among the existing technologies, hydrogen production electrolyzers are mainly divided into two categories: alkaline electrolyzers and proton exchange membrane (PEM) electrolyzers. Alkaline electrolyzers have occupied a large share of the market due to their simple structure and low material cost. However, this type of electrolyzer has certain limitations, especially its poor adaptability when facing power fluctuations, which limits its effective combination with intermittent renewable energy. In addition, the problem of difficulty in starting in low temperature environments also affects its scope of application.

[0004] In contrast, PEM electrolyzers are favored for their excellent power adaptability and wide operating temperature range. They can provide high-purity hydrogen over the entire temperature range and have fast response characteristics, enabling rapid startup to adapt to changes in power supply. However, due to the complex manufacturing process and the high cost of key materials, the price of PEM electrolyzers is relatively high, increasing the initial investment burden on users.

[0005] In view of the problems existing in the above two mainstream electrolyzers, it is difficult for the hydrogen production equipment currently on the market to meet the requirements of low cost and high efficiency at the same time. Summary of the invention

[0006] The present invention provides a hybrid electrolysis system and a hybrid electrolysis method, which are used to solve the defect that it is difficult to balance cost-effectiveness and power adaptability in the prior art, and realize efficient and economical green hydrogen production.

[0007] The present invention provides a hybrid electrolysis system, comprising: a PEM electrolysis device, comprising a PEM electrolysis cell, a first hydrogen separator, a first oxygen separator, a pure water cooler and a pure water circulation pump; an alkaline electrolysis device, comprising an alkaline electrolysis cell, a second hydrogen separator, a second oxygen separator, an alkaline liquid cooler and an alkaline liquid circulation pump; a heat exchanger, wherein in the PEM electrolysis device, the heat exchanger is connected between the pure water cooler and the pure water circulation pump, and in the alkaline electrolysis device, the heat exchanger is connected between the alkaline liquid cooler and the alkaline liquid circulation pump, and pure water of the PEM electrolysis device and alkaline liquid of the alkaline electrolysis device are heat-exchanged in the heat exchanger.

[0008] According to one embodiment of the present invention, the PEM electrolyzer is provided with an auxiliary heater for providing heat during the operation of the PEM electrolyzer.

[0009] According to one embodiment of the present invention, the auxiliary heater is a low-power electric heater with a power of 25 kW to 50 kW.

[0010] According to one embodiment of the present invention, in the PEM electrolysis device, a first straight-through pipeline and a first heat exchange pipeline connected in parallel are connected between the pure water cooler and the pure water circulation pump; the flow path of the first heat exchange pipeline passes through the heat exchanger; during the operation of the PEM electrolysis device, one of the first straight-through pipeline and the first heat exchange pipeline is connected.

[0011] According to one embodiment of the present invention, in the alkaline electrolysis device, a second straight pipeline and a second heat exchange pipeline connected in parallel are connected between the alkali solution cooler and the alkali solution circulation pump; the flow path of the second heat exchange pipeline passes through the heat exchanger; when the first heat exchange pipeline is connected, the second heat exchange pipeline is connected, so that the pure water of the PEM electrolysis device and the alkali solution of the alkaline electrolysis device are heat exchanged in the heat exchanger through the first heat exchange pipeline and the second heat exchange pipeline respectively.

[0012] According to one embodiment of the present invention, a pure water temperature detection unit is provided, and the pure water temperature detection unit is located at the outlet of the pure water cooler of the PEM electrolysis device; the PEM electrolysis device is configured to switch the first heat exchange pipeline to be connected when the detected pure water temperature reaches a preset threshold during the cold start process.

[0013] According to one embodiment of the present invention, an alkali solution temperature detection unit is provided, and the alkali solution temperature detection unit is located at the outlet of the alkali solution cooler of the alkaline electrolysis device; the alkaline electrolysis device is configured to supply power to the alkaline electrolysis cell to put it into a hydrogen production working state when the detected alkali solution temperature rises above a preset threshold value.

[0014] The present invention also provides a hybrid electrolysis method for controlling the hybrid electrolysis system of the above-mentioned embodiment to perform the electrolysis hydrogen production process, the method comprising: preferentially starting the PEM electrolysis device; monitoring the fluid temperature in the PEM electrolysis device, and when the fluid temperature reaches a first preset threshold, starting a heat transfer process; during the heat transfer process, monitoring the fluid temperature in the alkaline electrolysis device, and when the fluid temperature rises above a second preset threshold, starting the alkaline electrolysis device to enter a hydrogen production working state.

[0015] According to one embodiment of the present invention, the step of preferentially starting the PEM electrolysis device includes: starting the PEM electrolysis device and a heating device thereof to increase the temperature of the fluid inside the PEM electrolysis device.

[0016] According to one embodiment of the present invention, the step of monitoring the fluid temperature in the alkaline electrolysis device includes: continuously monitoring the fluid temperature in the alkaline electrolysis device; and starting the power supply of the alkaline electrolysis device when the fluid temperature reaches a second preset threshold.

[0017] The hybrid electrolysis system and hybrid electrolysis method provided by the present invention realize heat recovery and utilization of the two by organically combining a PEM electrolysis device with an alkaline electrolysis device and introducing a heat exchanger. The PEM electrolysis device that is started first can quickly respond to changes in power supply and adapt to a wide range of operating temperatures, ensuring the power adaptability and startup speed of the system; and when the heat generated by the PEM electrolysis device reaches a certain threshold, this part of the heat is effectively transferred to the alkaline electrolysis device through the heat exchanger, which not only improves the energy utilization rate, but also solves the problem of difficulty in starting the alkaline electrolyzer at low temperature. As the temperature of the fluid in the alkaline electrolysis device rises to a suitable operating level, it is added to the hydrogen production process, making full use of its cost-effectiveness advantage for large-scale hydrogen production. Therefore, the present invention realizes the complementary advantages of the two electrolysis technologies, which not only reduces the overall operating cost, but also ensures efficient and stable green hydrogen output, successfully overcoming the defects of the prior art that it is difficult to balance cost-effectiveness and power adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is a schematic diagram of the system connection relationship of the hybrid electrolysis system provided by the present invention.

[0020] Figure 2It is a schematic flow chart of the hybrid electrolysis method provided by the present invention.

[0021] Reference numerals: 11. PEM electrolyzer; 12. First hydrogen separator; 13. First oxygen separator; 14. Pure water cooler; 15. Pure water circulation pump; 16. First straight pipeline; 17. First heat exchange pipeline; 21. Alkaline electrolyzer; 22. Second hydrogen separator; 23. Second oxygen separator; 24. Alkaline solution cooler; 25. Alkaline solution circulation pump; 26. Second straight pipeline; 27. Second heat exchange pipeline; 30. Heat exchanger. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. It should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "set", "install", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0024] Combine the following Figure 1 The specific embodiment of the hybrid electrolysis system of the present invention is described.

[0025] The present invention provides a hybrid electrolysis system, comprising: a PEM electrolysis device, comprising a PEM electrolysis cell 11, a first hydrogen separator 12, a first oxygen separator 13, a pure water cooler 14 and a pure water circulation pump 15; an alkaline electrolysis device, comprising an alkaline electrolysis cell 21, a second hydrogen separator 22, a second oxygen separator 23, an alkaline liquid cooler 24 and an alkaline liquid circulation pump 25; a heat exchanger 30, wherein in the PEM electrolysis device, the heat exchanger 30 is connected between the pure water cooler 14 and the pure water circulation pump 15, and in the alkaline electrolysis device, the heat exchanger 30 is connected between the alkaline liquid cooler 24 and the alkaline liquid circulation pump 25, and the pure water of the PEM electrolysis device and the alkaline liquid of the alkaline electrolysis device are heat-exchanged in the heat exchanger 30.

[0026] Specifically, the hybrid electrolysis system integrates the advantages of the PEM electrolyzer 11 and the alkaline electrolyzer 21 to achieve the collaborative operation of two different types of electrolyzers in the same system. With its fast startup capability and good power adaptability, the PEM electrolyzer 11 can respond quickly to changes in power supply and provide the heat required for the initial operation of the entire system. At the same time, the alkaline electrolyzer 21, with its lower cost advantage, overcomes the problem of difficulty in starting in a low temperature environment after receiving the heat transferred from the PEM electrolyzer 11, and enters an efficient hydrogen production state. This combination not only improves the overall efficiency of the system, but also reduces operating costs, ensuring the economy and environmental protection of hydrogen production.

[0027] During use, the first to be started is the PEM electrolyzer 11, which can preferentially start the electrolysis process and generate heat. As the temperature of the PEM electrolyzer 11 rises, the generated heat energy is effectively transferred to the alkaline electrolyzer 21 through the heat exchanger 30, helping the latter to preheat to a suitable working temperature. Once it is monitored that the fluid temperature in the alkaline electrolyzer 21 reaches the set safety threshold, the cell can be started for synchronous hydrogen production. The two electrolyzers each have an independent hydrogen and oxygen separation system, which ensures that the quality of the gas produced by each is not affected, while avoiding the risk of cross contamination. In addition, with the help of a sophisticated sensor control system, the operating parameters of the two can be monitored and adjusted in real time to maintain the best working state.

[0028] Furthermore, the hybrid electrolysis system can optimize the operation process by integrating advanced control logic, such as introducing intelligent algorithms to automatically adjust the heat distribution between the PEM electrolyzer 11 and the alkaline electrolyzer 21, flexibly switching the main hydrogen production source according to actual needs, or operating a certain type of electrolyzer alone when necessary, so that the system has higher flexibility and reliability, and can automatically make the most appropriate response according to changes in external conditions (such as electricity price fluctuations or ambient temperature). In addition, in order to enhance the comprehensive performance of the system, it is also possible to consider adding an energy storage unit to store excess electrical energy or thermal energy so as to provide additional power support when needed, further improving energy utilization efficiency and economic benefits.

[0029] The above-mentioned alkaline electrolyzer 21 adopts an electrolyzer without auxiliary heating, and the PEM electrolyzer 11 can use an electrolyzer with or without auxiliary heating according to the specific application environment. Preferably, according to a hybrid electrolysis system of the present invention, the PEM electrolyzer 11 is provided with an auxiliary heater for providing heat during the operation of the PEM electrolysis device. Specifically, the provision of the auxiliary heater enables the PEM electrolyzer 11 to quickly reach its optimal operating temperature at the initial start-up or in a low temperature environment, ensuring that the electrolysis process is carried out efficiently. When the PEM electrolyzer 11 is equipped with an auxiliary heater, it can not only maintain stable operating conditions when the power supply is unstable or the ambient temperature is low, but also increase the system temperature in a short time, accelerating the process of heat transfer to the alkaline electrolyzer 21.

[0030] The working principle of the auxiliary heater is to directly heat the electrolyte in the PEM electrolyzer 11 or the surrounding environment through electric heating or other forms of heat energy input, which can ensure that even under unfavorable external conditions, the PEM electrolyzer 11 can quickly enter the working state and effectively transfer the generated heat energy to the alkaline electrolyzer 21 through the heat exchanger 30, helping the latter to overcome the problem of low-temperature startup. At the same time, the auxiliary heater can also intelligently adjust the output power according to the actual needs of the system to maximize energy utilization and minimize operating costs.

[0031] Furthermore, according to a hybrid electrolysis system of the present invention, the auxiliary heater is a low-power electric heater with a power of 25 kW to 50 kW. Specifically, based on comprehensive considerations of energy efficiency, cost control, and actual application scenario requirements, the low-power electric heater can provide sufficient heat to ensure that the PEM electrolyzer 11 quickly reaches and maintains the optimal operating temperature without significantly increasing the operating cost.

[0032] Preferably, the low-power electric heater can provide necessary additional heat energy at the initial startup of the PEM electrolyzer 11 or when encountering extremely low temperatures, helping the electrolyzer to overcome the initial cold start challenge and accelerate the preheating process. Once the PEM electrolyzer 11 enters a stable operating state, the auxiliary heater can reduce power or work intermittently, supplementing heat only when needed, thereby avoiding unnecessary energy waste.

[0033] In addition, electric heaters within this power range are compatible with most existing power infrastructures, without the need for large-scale grid transformation or additional power expansion investment. For renewable energy power supply scenarios, such as wind power generation or solar photovoltaic power generation, low-power electric heaters can use this energy for heating when these energy sources generate excess electricity, further improving the environmental protection and economic efficiency of the system.

[0034] According to a hybrid electrolysis system of the present invention, in a PEM electrolysis device, a first straight-through pipeline 16 and a first heat exchange pipeline 17 connected in parallel are connected between a pure water cooler 14 and a pure water circulation pump 15; the flow path of the first heat exchange pipeline 17 passes through a heat exchanger 30; during the operation of the PEM electrolysis device, the first straight-through pipeline 16 and the first heat exchange pipeline 17 are selectively connected. Specifically, by providing the first straight-through pipeline 16 and the first heat exchange pipeline 17 connected in parallel, and selectively connecting one of the two, flexible control of pure water cooling and heat recovery is achieved.

[0035] When the PEM electrolyzer 11 is in the initial stage of startup or needs to be heated up quickly, the first heat exchange pipeline 17 can be closed and the first direct pipeline 16 can be opened to allow cooling water to flow directly through the pure water circulation pump 15 back to the PEM electrolyzer 11, thereby avoiding unnecessary heat loss and accelerating the temperature rise. This helps the PEM electrolyzer 11 to quickly reach the operating temperature, especially in a low temperature environment or cold start, to ensure its rapid response capability.

[0036] As the PEM electrolyzer 11 enters a stable operating state and the temperature reaches a certain threshold, the system can switch to the first heat exchange pipeline 17. At this time, pure water flows through the heat exchanger 30, transferring the excess heat generated by the PEM electrolyzer 11 to the alkaline electrolyzer 21, helping the latter to preheat or maintain a suitable operating temperature. This heat recovery mechanism not only improves the energy efficiency of the entire hybrid electrolysis system, reduces the energy input required for external heating, but also effectively solves the problem of difficulty in starting the alkaline electrolyzer 21 at low temperatures.

[0037] In addition, this selective connection design also provides additional operational flexibility. For example, when the external ambient temperature is high or the PEM electrolyzer 11 itself generates a lot of heat, overheating can be prevented by selecting a straight-through pipeline; and when more heat needs to be transferred to the alkaline electrolyzer 21, it is switched to the heat exchange pipeline. In this way, the system can automatically adjust the optimal path according to the real-time operating conditions to ensure an efficient and stable hydrogen production process.

[0038] According to a hybrid electrolysis system of the present invention, in an alkaline electrolysis device, a second straight-through pipeline 26 and a second heat exchange pipeline 27 connected in parallel are connected between an alkali liquid cooler 24 and an alkali liquid circulation pump 25; the flow path of the second heat exchange pipeline 27 passes through a heat exchanger 30; when the first heat exchange pipeline 17 is connected, the second heat exchange pipeline 27 is connected, so that the pure water of the PEM electrolysis device and the alkali liquid of the alkaline electrolysis device are heat-exchanged in the heat exchanger 30 through the first heat exchange pipeline 17 and the second heat exchange pipeline 27, respectively. Specifically, by setting the second straight-through pipeline 26 and the second heat exchange pipeline 27 connected in parallel, and connecting one of the two, effective control of alkali liquid cooling and heat recovery is achieved.

[0039] When the first heat exchange pipeline 17 (located in the PEM electrolysis device) is connected, the second heat exchange pipeline 27 is also connected synchronously, so that the pure water of the PEM electrolysis device and the alkaline solution of the alkaline electrolysis device are heat exchanged in the heat exchanger 30 through their respective corresponding heat exchange pipelines. This process not only makes full use of the excess heat generated by the PEM electrolysis cell 11, helping the alkaline electrolysis cell 21 to quickly reach the operating temperature, but also reduces the need for external heating sources, thereby reducing the overall operating cost.

[0040] According to a hybrid electrolysis system of the present invention, a pure water temperature detection unit is provided, and the pure water temperature detection unit is located at the outlet of the pure water cooler 14 of the PEM electrolysis device; the PEM electrolysis device is configured to switch the first heat exchange pipeline 17 to be connected when the detected pure water temperature reaches a preset threshold value during the cold start process. The pure water temperature detection unit ensures accurate monitoring of the pure water temperature in the PEM electrolysis cell 11, especially during the cold start process, when the detected pure water temperature reaches a preset threshold value, the system can automatically switch to the first heat exchange pipeline 17 for connection.

[0041] Specifically, when the PEM electrolyzer 11 starts to operate, since it needs to heat up quickly to reach the operating temperature, the first direct pipeline 16 remains connected at this time, so that the cooling water circulates directly, helping the PEM electrolyzer 11 to heat up quickly. As the PEM electrolyzer 11 gradually heats up, the pure water temperature detection unit monitors the temperature at the outlet of the pure water cooler 14 in real time. Once it is detected that the temperature reaches the preset threshold, the system automatically triggers the switching mechanism to switch the water flow from the first direct pipeline 16 to the first heat exchange pipeline 17. After the switch, the pure water flows through the heat exchanger 30 through the first heat exchange pipeline 17 and begins to transfer heat to the alkaline electrolyzer 21. This not only makes full use of the excess heat generated by the PEM electrolyzer 11, but also helps the alkaline electrolyzer 21 overcome the problem of difficulty in starting at low temperatures, thereby improving the energy utilization efficiency of the entire system.

[0042] According to a hybrid electrolysis system of the present invention, an alkali solution temperature detection unit is provided, and the alkali solution temperature detection unit is located at the outlet of the alkali solution cooler 24 of the alkaline electrolysis device; the alkaline electrolysis device is configured to supply power to the alkaline electrolysis cell 21 when the detected alkali solution temperature rises above a preset threshold value, so that it enters a hydrogen production working state. The alkali solution temperature detection unit allows the alkali solution temperature in the alkaline electrolysis cell 21 to be accurately monitored, so that when the detected alkali solution temperature rises above a preset threshold value, the system automatically supplies power to the alkaline electrolysis cell 21, so that it enters a hydrogen production working state.

[0043] Specifically, when the system is started or the ambient temperature is low, the alkaline electrolyzer 21 may require additional preheating time. At this time, the alkali solution temperature detection unit continuously monitors the temperature changes at the outlet of the alkali solution cooler 24. Once the alkali solution temperature rises to a preset threshold, it indicates that the alkaline electrolyzer 21 has reached a suitable operating temperature. At this time, the system automatically supplies power to the alkaline electrolyzer 21 to start the hydrogen production process. After the alkaline electrolyzer 21 enters the hydrogen production working state, it continuously monitors the alkali solution temperature to ensure that it remains within a stable range, thereby ensuring efficient hydrogen production. In addition, this temperature control mechanism can also prevent equipment damage or energy waste due to excessive temperature.

[0044] Through precise temperature monitoring and intelligent control systems, the hybrid electrolysis system of the preferred embodiment of the present invention can achieve efficient collaborative work between the PEM electrolysis device and the alkaline electrolysis device. Specifically, the PEM electrolyzer 11 is equipped with a low-power auxiliary heater for startup (power range is 25kW to 50kW) to ensure that the optimal working temperature can be quickly reached in cold start or low temperature environment; while the alkaline electrolyzer 21 adopts a non-auxiliary heat design, relying on the heat transferred by the PEM electrolyzer 11 for preheating, overcoming the problem of low-temperature startup difficulties of the traditional alkaline electrolyzer 21. A heat exchange design is provided between the pure water circulation system and the alkali liquid circulation system, including a first straight-through pipeline 16 and a first heat exchange pipeline 17 (for the PEM electrolysis device) connected in parallel, and a second straight-through pipeline 26 and a second heat exchange pipeline 27 (for the alkaline electrolysis device); when the detected pure water temperature reaches the preset threshold, the system automatically switches to the heat exchange mode, so that the heat generated by the PEM electrolyzer 11 is effectively transferred to the alkaline electrolyzer 21. According to the preset startup sequence, after the PEM electrolysis device is started first and heated to a suitable temperature, the heat is transferred to the alkaline electrolysis device through the heat exchanger 30; once the alkali solution temperature in the alkaline electrolysis cell 21 rises above the preset threshold, the system supplies power to it to put it into hydrogen production working state. Through the above scheme, not only the energy utilization efficiency of the system is optimized, but also it is ensured that the two electrolysis devices can operate under the best conditions, which improves the overall performance and reliability of the system and provides strong technical support for efficient and economical green hydrogen production.

[0045] According to a preferred embodiment of the hybrid electrolysis system of the present invention, the specific details are as follows: The PEM electrolyzer was equipped with a 50kW auxiliary heater and started at a starting temperature of 5°C. After 20 minutes, the temperature of the PEM system successfully rose to 50°C, indicating that the cold start was successfully completed. An example of the temperature change is shown in Table 1.

[0046] Table 1:

[0047] On the other hand, an alkaline electrolyzer with a capacity of 1000 Nm³ is also started at the same initial temperature of 5°C. Since this alkaline electrolyzer adopts a design without auxiliary heating, within the first 20 minutes, it heats up to 32.8°C by its own operation. Subsequently, with the heat provided by the PEM electrolyzer for heat exchange, the alkaline electrolyzer (ALK system) further increases its temperature to 50°C within an additional 11 minutes, that is, after a total of 31 minutes, successfully reaching the appropriate operating temperature and entering the hydrogen production working state. An example of its temperature change is shown in Table 2.

[0048] Table 2:

[0049] Through the efficient heat transfer between the PEM electrolyzer and the alkaline electrolyzer, it not only ensures the rapid cold start of the PEM electrolyzer, but also significantly shortens the time required for the alkaline electrolyzer to reach the operating temperature, thereby improving the start-up efficiency and energy utilization efficiency of the entire system.

[0050] The hybrid electrolysis method provided by the present invention will be described below. The hybrid electrolysis method described below can be correspondingly referred to the hybrid electrolysis system described above.

[0051] The present invention also provides a hybrid electrolysis method for controlling the hybrid electrolysis system of the above-described embodiment to perform the electrolysis hydrogen production process. Figure 2 is a schematic flow chart of the hybrid electrolysis method provided by the present invention. As Figure 2 shown, the method includes the following: Step 110: Preferentially start the PEM electrolysis device. Specifically, first start the PEM electrolysis device. When the initial temperature is lower than 5°C, raise the temperature of the pure water inside the PEM electrolyzer to ensure that it reaches the appropriate operating conditions as soon as possible.

[0052] Step 120: Monitor the fluid temperature in the PEM electrolysis device. When the fluid temperature reaches the first preset threshold, start the heat transfer process. Specifically, after the PEM electrolysis device is started, the system continuously monitors the fluid temperature at the outlet of the pure water cooler. Once it is detected that the pure water temperature reaches the first preset threshold (for example, 50°C), the system automatically switches to the first heat exchange pipeline connection mode, allowing the pure water to flow through the heat exchanger. At this time, the excess heat generated by the PEM electrolyzer starts to be transferred to the alkaline electrolyzer to help the latter preheat. This process not only improves the energy utilization efficiency but also creates favorable conditions for the subsequent start-up of the alkaline electrolyzer.

[0053] Step 130: During the heat transfer process, the fluid temperature in the alkaline electrolysis device is monitored. When the fluid temperature rises above the second preset threshold, the alkaline electrolysis device is started to enter the hydrogen production working state. Specifically, during the heat transfer process, the system monitors the alkali liquid temperature at the outlet of the alkali liquid cooler in real time. As the heat received from the PEM electrolyzer gradually increases, the alkali liquid temperature in the alkaline electrolyzer will also rise accordingly. When it is detected that the alkali liquid temperature rises above the second preset threshold (for example, 50°C), it indicates that the alkaline electrolyzer has reached a suitable operating temperature. At this time, the system automatically supplies power to the alkaline electrolyzer, so that it officially enters the hydrogen production working state.

[0054] In the above scheme, during the cold start process (<5°C), the PEM electrolyzer is started first, and its auxiliary heater is used to quickly increase the temperature. When the pure water temperature in the PEM electrolyzer exceeds 50°C, the heat is efficiently transferred to the alkaline electrolyzer through the heat exchange device. Subsequently, the system continues to monitor the temperature changes of the alkaline electrolyzer. Once the temperature of the alkaline electrolyzer reaches above 50°C, the alkaline electrolyzer is powered on to enable it to smoothly enter the hydrogen production working state. This startup sequence and temperature control mechanism not only optimizes the energy management of the system, but also significantly improves the startup efficiency and operating stability of the entire hybrid electrolysis system.

[0055] Further, according to a hybrid electrolysis method of the present invention, in the step of preferentially starting the PEM electrolysis device, the method comprises: Step 111, start the PEM electrolysis device and its heating equipment to increase the temperature of the fluid inside the PEM electrolysis device. Specifically, turn on the power of the PEM electrolysis device and activate its built-in low-power auxiliary heater (power range is 25kW to 50kW), so that the PEM electrolysis cell can quickly heat up in a cold start or low temperature environment. The auxiliary heater directly heats the pure water in the PEM electrolysis cell, and at the same time starts the pure water circulation pump to evenly distribute the heat energy throughout the system. In this way, the temperature of the fluid inside the PEM electrolysis device can be quickly increased so that it can reach suitable working conditions as soon as possible.

[0056] Furthermore, according to a hybrid electrolysis method of the present invention, in the step of monitoring the temperature of the fluid in the alkaline electrolysis device, the method comprises: Step 131, continuously monitor the temperature of the fluid in the alkaline electrolysis device. Specifically, during the heat transfer process, the system uses a temperature detection unit arranged at the outlet of the alkali liquid cooler to monitor the temperature changes of the fluid in the alkaline electrolysis device in real time. The temperature data is analyzed by an intelligent control system to ensure that any temperature fluctuations can be responded to in a timely manner. This continuous monitoring mechanism not only helps to accurately grasp the preheating progress of the alkaline electrolyzer, but also prevents equipment damage or decreased hydrogen production efficiency due to abnormal temperature. In addition, by comparing with the preset threshold, the system can automatically adjust the working mode of the heat exchanger to optimize the heat transfer efficiency.

[0057] Step 132, when the fluid temperature reaches the second preset threshold, start the power supply of the alkaline electrolysis device. Specifically, once the alkali solution temperature rises above the second preset threshold (for example, 50°C), it indicates that the alkaline electrolyzer has reached a suitable operating temperature. At this time, the system automatically triggers the power supply instruction to provide power to the alkaline electrolyzer, so that it officially enters the hydrogen production working state. This process is preferably automated through an intelligent control system to ensure the accuracy and reliability of the power supply timing. In addition, the system preferably continues to monitor the alkali solution temperature and maintains it within a stable range to ensure efficient hydrogen production. If the temperature exceeds the safety upper limit, the system can automatically take measures to reduce the power or suspend the power supply to protect the equipment from overheating damage.

[0058] In the hybrid electrolysis method of the preferred embodiment of the present invention, efficient collaborative work between the 200 Nm³ PEM electrolyzer and the 1000 Nm³ alkaline electrolyzer is achieved through precise control and intelligent management system.

[0059] First, during the cold start process, the PEM electrolyzer is equipped with a 50kW low-power auxiliary heater, which can quickly heat up at a starting temperature of 5°C. After 20 minutes, the PEM system temperature reached 50°C, indicating that the cold start was successfully completed. At the same time, the pure water circulation pump is started to ensure that the heat energy is evenly distributed, so that the PEM electrolyzer quickly enters the optimal working state. Subsequently, the system automatically switches to the heat exchange mode, so that the heat generated by the PEM electrolyzer is transferred to the alkaline electrolyzer through the heat exchanger. This process not only improves the energy utilization efficiency, but also provides the necessary preheating conditions for the alkaline electrolyzer.

[0060] Next, the 1000 Nm³ alkaline electrolyzer was also started at a starting temperature of 5°C. Due to the non-auxiliary heat design, the alkaline electrolyzer heated up to 32.8°C through its own operation within the first 20 minutes. With the heat provided by the PEM electrolyzer for heat exchange, the temperature of the alkaline electrolyzer increased from 32.8°C to 50°C in an additional 15 minutes, successfully shortening the overall startup time by about 5-6 minutes. In this way, the PEM electrolyzer was able to provide 310kW of heat in 15 minutes, causing the alkaline electrolyzer system to heat up by 4.97°C. This not only speeds up the startup of the alkaline electrolyzer, but also significantly reduces the power consumption caused by low-temperature startup.

[0061] The heat provided by the PEM electrolyzer allows the alkaline electrolyzer to reach a suitable operating temperature in a relatively short time, avoiding the large amount of electricity required for long-term preheating in traditional methods. The entire system optimizes energy utilization efficiency and reduces unnecessary energy waste, while ensuring that two different types of electrolyzers work efficiently together in the same system, which not only improves the system startup speed, but also reduces startup costs, providing reliable technical support for the large-scale commercial production of green hydrogen.

[0062] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "mode", "specific mode", or "some modes" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or mode are included in at least one embodiment or mode of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or mode. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or modes in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or modes described in this specification and the features of the different embodiments or modes, without contradiction.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hybrid electrolysis system, characterized in that: include: A PEM electrolysis device, comprising a PEM electrolysis cell, a first hydrogen separator, a first oxygen separator, a pure water cooler and a pure water circulation pump; An alkaline electrolysis device, comprising an alkaline electrolysis tank, a second hydrogen separator, a second oxygen separator, an alkaline solution cooler and an alkaline solution circulation pump; A heat exchanger, in the PEM electrolysis device, the heat exchanger is connected between the pure water cooler and the pure water circulation pump, and in the alkaline electrolysis device, the heat exchanger is connected between the alkali solution cooler and the alkali solution circulation pump, and the pure water of the PEM electrolysis device and the alkali solution of the alkaline electrolysis device are heat-exchanged in the heat exchanger.

2. The hybrid electrolysis system according to claim 1, characterized in that: The PEM electrolyzer is provided with an auxiliary heater for providing heat during the operation of the PEM electrolyzer.

3. The hybrid electrolysis system according to claim 2, characterized in that: The auxiliary heater is a low-power electric heater with a power of 25 kW to 50 kW.

4. The hybrid electrolysis system according to any one of claims 1 to 3, characterized in that: In the PEM electrolysis device, a first straight pipeline and a first heat exchange pipeline connected in parallel are connected between the pure water cooler and the pure water circulation pump; The flow path of the first heat exchange pipeline passes through the heat exchanger; During the operation of the PEM electrolysis device, either the first straight pipeline or the first heat exchange pipeline is connected.

5. The hybrid electrolysis system according to claim 4, characterized in that: In the alkaline electrolysis device, a second straight pipeline and a second heat exchange pipeline connected in parallel are connected between the alkali solution cooler and the alkali solution circulation pump; The flow path of the second heat exchange pipeline passes through the heat exchanger; When the first heat exchange pipeline is connected, the second heat exchange pipeline is connected so that the pure water of the PEM electrolysis device and the alkaline solution of the alkaline electrolysis device are heat exchanged in the heat exchanger through the first heat exchange pipeline and the second heat exchange pipeline respectively.

6. The hybrid electrolysis system according to claim 5, characterized in that: A pure water temperature detection unit is provided, and the pure water temperature detection unit is located at the outlet of the pure water cooler of the PEM electrolysis device; The PEM electrolysis device is configured to switch the first heat exchange pipeline to be connected when the detected pure water temperature reaches a preset threshold during a cold start process.

7. The hybrid electrolysis system according to claim 5, characterized in that: A alkali solution temperature detection unit is provided, and the alkali solution temperature detection unit is located at the outlet of the alkali solution cooler of the alkaline electrolysis device; The alkaline electrolysis device is configured to supply power to the alkaline electrolysis cell when the detected alkaline solution temperature rises above a preset threshold value, so that the alkaline electrolysis cell enters a hydrogen production working state.

8. A hybrid electrolysis method, characterized in that: The method for controlling the hybrid electrolysis system according to any one of claims 1 to 7 to perform an electrolysis hydrogen production process comprises: Prioritize starting the PEM electrolysis unit; monitoring the temperature of the fluid in the PEM electrolysis device, and starting a heat transfer process when the temperature of the fluid reaches a first preset threshold; During the heat transfer process, the temperature of the fluid in the alkaline electrolysis device is monitored, and when the temperature of the fluid rises above a second preset threshold, the alkaline electrolysis device is started to enter a hydrogen production working state.

9. The hybrid electrolysis method according to claim 8, characterized in that: The step of preferentially starting the PEM electrolysis device includes: The PEM electrolysis device and its heating device are started to increase the temperature of the fluid inside the PEM electrolysis device.

10. The hybrid electrolysis method according to claim 8 or 9, characterized in that: The step of monitoring the temperature of the fluid in the alkaline electrolysis device comprises: Continuously monitor the temperature of the fluid in the alkaline electrolysis unit; When the fluid temperature reaches a second preset threshold, the power supply to the alkaline electrolysis device is started.

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