CN114606509A - A thermal management system and method for a hydrogen production electrolyzer array - Google Patents

Abstract

The invention discloses a thermal management system and method for an array of hydrogen-producing electrolyzers. The system comprises a plurality of electrolyzers connected in parallel. The hydrogen outlet end and the oxygen outlet end of each electrolyzer are respectively connected with a hydrogen side gas-liquid separator and a hydrogen side gas-liquid separator. The gas-liquid separator on the oxygen side is connected, and the liquid discharge port of the gas-liquid separator on the hydrogen side and the liquid discharge port of the gas-liquid separator on the oxygen side are connected in parallel with one end of the first heat exchange channel of the heat exchanger. The other end of the channel is connected to the liquid inlet of the first one-way valve, the two ends of the second heat exchange channel of the heat exchanger are connected to the heat exchange loop, and the liquid outlet of the first one-way valve is connected to one end of the heater connection, the other end of the heater is connected with a plurality of parallel second one-way valves through the lye circulating pump, each second one-way valve is matched to the liquid inlet of an electrolytic cell, and the first one-way valve A lye supplementary branch is arranged between the liquid outlet and the heater. The beneficial effects of the invention are that the start-up time of the electrolytic cell array is greatly reduced, and the rapid response of the system is improved.

Description

A thermal management system and method for a hydrogen production electrolyzer array

technical field

The present invention relates to the technical field of new energy, and in particular, to a thermal management system and method for a hydrogen production electrolyzer array.

Background technique

Wind power is an important way to realize the utilization of renewable energy and promote carbon neutrality and carbon peaking. However, large-scale wind farms are prone to generate huge amounts of abandoned wind energy, resulting in a decline in energy utilization. The use of electrolyzed water hydrogen production technology can convert abandoned wind resources into green hydrogen energy, which can not only improve the economic benefits of wind farms, but also promote the development of the hydrogen energy industry, especially the application of hydrogen fuel cells in the field of transportation.

Alkaline electrolysis water hydrogen production technology is one of the most mature and lowest cost hydrogen production solutions. For large-scale wind farms, the power generation fluctuates greatly and the randomness is strong. Therefore, using multiple alkaline hydrogen production electrolyzers in parallel can not only improve the hydrogen production scale and the wide power fluctuation adaptability of the hydrogen production system, but also improve the hydrogen production system. The instantaneous response capability, overall efficiency and service life of the products, such as:

Chinese patent CN 111364052 A proposes to use multiple electrolyzers in parallel to reduce the lower limit of the hydrogen production power of the electrolysis system, thereby broadening the operating range of the hydrogen production power of the electrolysis system, making it suitable for fluctuating power supply occasions such as wind power generation or photovoltaic power generation;

Chinese patent CN 111826669 A proposes a large-scale electrolyzed water hydrogen production system and control method with wide power fluctuation adaptability. A plurality of electrolytic cells are used in parallel to form a hydrogen production module, and each module forms a large-scale hydrogen production system. Various module power shunt controllers control the power of each module separately, thereby improving the energy consumption efficiency of hydrogen production and wide power fluctuation adaptability, enhancing the instantaneous response speed and reducing the power loading cost;

Chinese patent CN 112103994 A proposes a predictive management method for electrolyzer arrays for electrolysis of water for hydrogen production. Through a rotation strategy, the operating power and operating time of each electrolyzer are reasonably allocated to balance the life of each electrolyzer;

To sum up, although the existing invention patents mention the use of electrolyzer arrays to improve the operation efficiency, wide power fluctuation adaptability and response time of large-scale renewable energy hydrogen production systems, each electrolyzer will generate considerable heat during operation. , it is obvious that the prior art fails to provide a specific comprehensive thermal management method to recover and utilize the heat generated by the electrolytic cell.

SUMMARY OF THE INVENTION

In view of the above problems, the present invention proposes a thermal management system and method for an array of hydrogen production electrolyzers, aiming to further improve the overall efficiency of the system by utilizing the heat generated by the electrolyzers during operation.

In order to solve the above technical problems, the first aspect of the present invention provides a thermal management system for an array of hydrogen production electrolyzers, comprising a plurality of electrolyzers connected in parallel, and the hydrogen outlet end and the oxygen outlet end of each of the electrolyzers are respectively connected to The hydrogen side gas-liquid separator is connected to the oxygen side gas-liquid separator, and the liquid discharge port of the hydrogen side gas-liquid separator and the liquid discharge port of the oxygen side gas-liquid separator are connected in parallel with the first exchange of the heat exchanger. One end of the heat channel is connected, the other end of the first heat exchange channel is connected to the liquid inlet of the first one-way valve, and both ends of the second heat exchange channel of the heat exchanger are connected to the heat exchange loop, The liquid outlet of the first one-way valve is connected to one end of the heater, and the other end of the heater is connected to a plurality of parallel second one-way valves through the lye circulating pump, each of the second one-way valves. All the direction valves are matched and connected to a liquid inlet of the electrolytic cell, and a lye supplementary branch is arranged between the liquid outlet of the first one-way valve and the heater.

In some embodiments, the heat exchange loop includes a heat exchange pipe, and a heat exchange pump installed in any section of the heat exchange pipe, and some pipes of the heat exchange pipe are installed inside the heat storage tank.

In some embodiments, the lye replenishment branch comprises an lye storage tank, and a lye replenishing pump installed at the outlet end of the lye storage tank, and the outlet end of the lye replenishing pump is installed at the first one-way between the liquid outlet of the valve and the heater.

In some embodiments, the second one-way valve is a one-way regulating valve.

A second aspect of the present invention provides a thermal management method for an array of hydrogen production electrolyzers, which is used in the above-mentioned system, comprising the following steps: detecting whether the temperature of the lye at the outlet of the lye circulating pump is lower than a preset threshold, and if so , then enter the cold start mode, if not, determine the number of the electrolyzers running according to the current wind power required to be consumed, and select to enter the low power mode or the high power mode according to the interval in which the number falls.

In some embodiments, the cold start mode includes: determining the number of the electrolyzers to operate according to the wind power that needs to be consumed currently, and turning on a corresponding number of the second units according to the number of the electrolyzers to operate. valve, and start the alkali replenishing pump, the alkali liquor circulation pump, the heater, and the heat exchange pump.

In some embodiments, the low power mode includes: opening a corresponding number of the second one-way valves according to the number of the electrolytic cells operating, and starting the alkali replenishment pump, the alkali liquor circulation pump, and The heat exchange pump turns off the heater.

In some embodiments, the high-power mode includes: opening a corresponding number of the second one-way valves according to the number of the electrolytic cells operating, and starting the alkali replenishing pump, the alkali liquor circulation pump, the The heat exchange pump, and the heater.

In some embodiments, during the operation of the electrolytic cell, it is continuously detected whether the temperature of the lye solution at the outlet end of the lye solution circulation pump is higher than the preset threshold value, and if so, the heater is turned off.

In some embodiments, during the operation of the electrolysis cell, it is continuously detected whether the temperature of the lye solution at the outlet end of the lye solution circulation pump is higher than the temperature of the lye solution stored in the heat storage tank and lower than the preset threshold value , and if so, turn off the heat exchange pump.

The beneficial effects of the present invention are as follows: by arranging a heat exchanger and a heat exchange loop at the liquid discharge ports of the hydrogen side gas-liquid separator and the oxygen side gas-liquid separator, it is used to absorb the heat of the lye and reduce the temperature of the lye in the system , to maintain the best electrolysis effect, and at the same time, a heater is installed at the liquid outlet of the first one-way valve, which can greatly reduce the start-up time of the electrolytic cell array and improve the rapid response of the system.

Description of drawings

1 is a schematic structural diagram of a thermal management system for an array of hydrogen production electrolyzers disclosed in Embodiment 1 of the present invention;

Among them: 1-electrolyzer, 2-hydrogen side gas-liquid separator, 3-oxygen side gas-liquid separator, 4-heat exchanger, 5-first check valve, 6-heat exchange loop, 7-heater , 8- lye circulating pump, 9- second one-way valve, 10- lye supplementary branch, 61- heat exchange pipeline, 62- heat exchange pump, 63- heat storage tank, 101- lye liquid storage tank, 102- Alkali make-up pump, 11-DC converter, 12-DC bus.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer and clearer, the content of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for the convenience of description, the drawings only show some but not all of the contents related to the present invention.

Example 1

This embodiment proposes a thermal management system for an array of hydrogen production electrolyzers, as shown in FIG. 1 , comprising a plurality of electrolyzers 1 in parallel, and the hydrogen outlet end and the oxygen outlet end of each electrolyzer 1 are respectively connected to the hydrogen The side gas-liquid separator 2 is connected to the oxygen side gas-liquid separator 3, and the liquid discharge port of the hydrogen side gas-liquid separator 2 and the liquid discharge port of the oxygen side gas-liquid separator 3 are connected in parallel with the first exchange of the heat exchanger 4. One end of the heat channel is connected, the other end of the first heat exchange channel is connected to the liquid inlet of the first one-way valve 5, both ends of the second heat exchange channel of the heat exchanger 4 are connected to the heat exchange loop 6, The liquid outlet of a one-way valve 5 is connected to one end of the heater 7, and the other end of the heater 7 is connected to a plurality of parallel second one-way valves 9 through the lye circulating pump 8, each second one-way valve 9 are matched to the liquid inlet of an electrolytic cell 1 , and a lye supplementary branch 10 is provided between the liquid outlet of the first one-way valve 5 and the heater 7 .

The alkaline electrolyzed water hydrogen production electrolyzer array consists of n (n greater than or equal to 2) electrolyzers 1 in parallel. The rated power of each electrolyzer 1 can be the same or different. In actual operation, each electrolyzer can be optimally controlled according to the efficiency. 1 hydrogen production. Specifically, when the electrolytic cell 1 is within the operable power range, its electrolysis efficiency tends to decrease with the increase of the electrolytic power. Therefore, using a plurality of electrolytic cells 1 in parallel to form an electrolytic cell array can not only reduce the minimum electrolysis power of the system, In addition to enhancing the wide power fluctuation of the system, the high-power command of a single electrolytic cell 1 can also be converted into a low-power command of multiple electrolytic cells to improve the efficiency of the electrolysis system.

In order to realize the independent control of each electrolytic cell 1 , each electrolytic cell 1 is powered by a DC converter 11 matching its rated power, and each DC converter 11 is connected to the DC bus 12 . Specifically, according to the amount of hydrogen production, the electrolysis power of each electrolytic cell 1 can be realized by controlling the current value of the DC converter 11; the hydrogen and oxygen generated by each electrolytic cell 1 are collected to the hydrogen side gas-liquid separation through one-way valves respectively. Device 2 and oxygen side gas-liquid separator 3, through the separator, the lye in the gas is separated and returned to the lye circulation pipeline (the direction of the first heat exchange channel of the heat exchanger 4), and the hydrogen and oxygen are sent into The follow-up treatment device performs drying, purification, cooling and other treatments.

The lye flow of each electrolytic cell 1 can be controlled by the second one-way valve 9 connected to it, so each electrolytic cell 1 shares a lye circulating pump 8, and the pumping pressure of the lye circulating pump 8 can be controlled by its input voltage is controlled. The lye precipitated from the hydrogen-side gas-liquid separator 2 and the oxygen-side gas-liquid separator 3 can be returned to the electrolyzer together with the lye solution stored in the lye solution supplementary branch 10. When the lye solution temperature in the system does not meet the When required, heat can be exchanged through the thermal management system.

The above-mentioned heat exchange loop 6 can be all heat exchange components that can be connected to the heat exchanger 4, and an optional embodiment is provided in this embodiment, that is, the heat exchange loop 6 includes a heat exchange pipe 61, As well as the heat exchange pump 62 installed in any section of the heat exchange pipe 61 , some pipes of the heat exchange pipe 61 are installed inside the heat storage tank 63 . The heat exchange loop 6 is used to cool the lye separated from the hydrogen-side gas-liquid separator 2 and the oxygen-side gas-liquid separator 3 , and store the heat in the heat storage tank 63 .

The above-mentioned lye replenishment branch circuit 10 is used to replenish lye solution for the electrolytic cell 1. Preferably, the lye solution replenishment branch circuit 10 includes an lye solution storage tank 101, and an alkali replenishing pump 102 installed at the outlet end of the lye solution storage tank 101 to replenish the lye solution. The outlet end of the alkali pump 102 is installed between the liquid outlet of the first check valve 5 and the heater 7 .

Further, the above-mentioned second one-way valve 9 is a one-way regulating valve.

In this embodiment, the heat exchanger 4 and the heat exchange loop 6 are mainly arranged at the liquid discharge ports of the hydrogen-side gas-liquid separator 2 and the oxygen-side gas-liquid separator 3, so as to absorb the heat of the lye and reduce the system's The temperature of the lye solution is maintained to maintain the best electrolysis effect. At the same time, the heater 7 is installed at the liquid outlet of the first one-way valve 5, which can greatly reduce the start-up time of the electrolytic cell array and improve the rapid response of the system. The heating management system can improve the hydrogen production efficiency and response speed in a wide power range through power distribution optimization and hydrogen production waste heat utilization, thereby improving the economic benefits of large-scale wind power hydrogen production.

Embodiment 2

A thermal management method for an array of hydrogen production electrolyzers, used in the system described in Embodiment 1, comprising the following steps: detecting whether the temperature of the lye solution at the outlet of the lye solution circulating pump 8 is lower than a preset threshold, and if so, entering the Cold start mode, if not, determine the number of electrolyzers 1 running according to the current wind power required to be consumed, and select to enter low power mode or high power mode according to the interval in which the number falls. The above interval is set by itself according to the total design quantity of electrolytic cell 1. For example, the current electrolytic cell 1 array has 200 electrolytic cells. In the early stage of consumption, if only 20 or less electrolyzers 1 are working, choose to enter the low-power mode; otherwise, choose to enter the high-power mode.

The cold start mode includes: determining the number of electrolyzers 1 operating according to the current wind power required to be consumed, opening a corresponding number of second one-way valves 9 according to the number of electrolyzers 1 operating, and starting the alkali replenishing pump 102, alkali Liquid circulation pump 8 , heater 7 , and heat exchange pump 62 . When only a few electrolyzers 1 are working in the system and multiple standby electrolyzers 1 with lower temperature are suddenly started, the lye can also be heated through the heat storage tank 63, so that the temperature of the electrolyzers 1 to be started rises and the start-up speed is accelerated.

The low power mode includes: opening a corresponding number of second one-way valves 9 according to the number of electrolytic cells 1 running, starting the alkali replenishing pump 102 , the lye circulating pump 8 , and the heat exchange pump 62 , and turning off the heater 7 . When the electrolysis power of the system is low, for example, only one or a few electrolytic cells 1 are running at low power, and the heat generated is not enough to meet the temperature requirements of the lye solution or not enough to make the electrolytic cells 1 operate with the best efficiency, The lye can be heated through the heat exchange loop 6 using the heat stored in the heat storage tank 63 .

The high-power mode includes: opening a corresponding number of second one-way valves 9 according to the number of electrolytic cells 1 running, and starting the alkali replenishing pump 102 , the lye circulating pump 8 , the heat exchange pump 62 , and the heater 7 . When the electrolysis power of the system is relatively large, such as when multiple electrolytic cells 1 are running at high power at the same time and the temperature of the circulating lye is too high, the circulating lye can be cooled through the heat exchange loop 6, and the heat can be stored in the storage in hot tank 63.

During the operation of the electrolytic cell 1, it is continuously detected whether the temperature of the lye at the outlet of the lye circulating pump 8 is higher than the preset threshold, and if so, the heater 7 is turned off.

During the operation of the electrolytic cell 1, it is continuously detected whether the lye temperature at the outlet of the lye circulating pump 8 is higher than the lye temperature stored in the heat storage tank 7 and lower than the preset threshold, and if so, the heat exchange pump 62 is turned off. When the heat in the heat storage tank 63 is not enough to heat the lye to increase the temperature of the electrolytic cell 1 (that is, the heat in the heat storage tank 63 is not enough to heat the lye in the main road where the lye circulating pump 8 is located), it should be avoided. The reverse of the heat storage tank 63 absorbs heat, so the heat exchange pump 62 needs to be turned off. At this time, the heater 7 should continue to heat the lye in the system. There is a temperature control system inside the heat storage tank 63. When the temperature of the heat storage tank 63 is too high, the heat medium of the heat storage tank 63 can flow out from the outlet, and the cooling medium is input into the heat storage tank 63 through the inlet to reduce the temperature of the heat storage tank 63. temperature to ensure the cooling effect of lye.

Since in the low power mode, when the wind power to be consumed is small, only a small number of electrolytic cells 1 and their corresponding second one-way valves 9 are opened, and the system stores the heat generated by the running electrolytic cells 1 in the storage tank. In the hot tank 63, when the wind power to be consumed increases, the remaining electrolyzers are started according to the magnitude of the power increase, and the high-power mode is entered. The temperature of the lye liquid in the lye liquid circulation channel drops. At this time, the heat in the heat storage tank 63 can be used to quickly heat the lye liquid circulation path through the thermal management system, so as to ensure that the opened electrolytic cell 1 maintains the normal working temperature and accelerates the start-up process. The electrolyzer 1 is put into operation, reducing the response time of the system for hydrogen production and power consumption. In addition, the heater configured on the lye circulation path can be used to temporarily heat the lye, especially, when the electrolytic cell array is just started and the temperature of the heat storage tank 63 is too low, the heater 7 can rapidly increase the temperature of the lye, Guaranteed fast response of electrolytic cell 1.

Specifically, when only a few electrolytic cells 1 are working in the system and multiple standby electrolytic cells with lower temperature are suddenly activated, the lye can be heated by the heater 7, thereby greatly reducing the startup time of the electrolytic cell array and improving the rapid response of the system. .

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and the purpose thereof is to enable those of ordinary skill in the art to understand the content of the present invention and implement them accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the essence of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A thermal management system for an array of hydrogen-producing electrolyzers, characterized in that it comprises a plurality of electrolyzers in parallel, and the hydrogen outlet end and the oxygen outlet end of each of the electrolyzers are respectively connected with a hydrogen side gas-liquid separator. It is connected with the gas-liquid separator on the oxygen side, and the liquid discharge port of the gas-liquid separator on the hydrogen side and the liquid discharge port of the gas-liquid separator on the oxygen side are connected in parallel with one end of the first heat exchange channel of the heat exchanger. , the other end of the first heat exchange channel is connected to the liquid inlet of the first one-way valve, the two ends of the second heat exchange channel of the heat exchanger are connected to the heat exchange loop, and the first one-way valve The liquid outlet of the valve is connected to one end of the heater, and the other end of the heater is connected to a plurality of parallel second one-way valves through the lye circulating pump, and each of the second one-way valves is matched and connected A liquid inlet of the electrolytic cell, and a lye supplementary branch is arranged between the liquid outlet of the first one-way valve and the heater. 2. The thermal management system for a hydrogen production electrolyzer array according to claim 1, wherein the heat exchange loop comprises a heat exchange pipe, and a heat exchange pump installed in any section of the heat exchange pipe, Parts of the heat exchange pipes are installed inside the heat storage tank. 3. The thermal management system for an array of hydrogen production electrolyzers according to claim 2, wherein the lye replenishment branch comprises an lye storage tank, and a replenisher installed at the outlet end of the lye storage tank. An alkali pump, the outlet end of the alkali replenishing pump is installed between the liquid outlet of the first one-way valve and the heater. 4. The thermal management system for a hydrogen production electrolyzer array according to claim 3, wherein the second one-way valve is a one-way regulating valve. 5. A method of thermal management for an array of hydrogen-producing electrolyzers, for use in the system of claim 4, comprising the steps of: Detecting whether the lye temperature at the outlet of the lye circulating pump is lower than a preset threshold, and if so, entering a cold start mode, if not, determining the number of the electrolyzers to operate according to the current wind power that needs to be consumed, And select to enter the low power mode or the high power mode according to the interval in which the number falls. 6 . The thermal management system for a hydrogen production electrolyzer array according to claim 5 , wherein the cold start mode comprises: determining the number of the electrolyzers to operate according to the wind power that needs to be consumed currently. 7 . , open a corresponding number of the second one-way valves according to the number of the electrolytic cells in operation, start the alkali replenishing pump, the alkali liquid circulation pump, and the heater, and close the heat exchange pump. 7. The thermal management system for an array of hydrogen production electrolyzers according to claim 5, wherein the low power mode comprises: turning on a corresponding number of the second cells according to the number of the electrolyzers operating valve, and start the alkali replenishing pump, the alkali liquor circulation pump, the heat exchange pump, and the heater. 8. The thermal management system for an array of hydrogen production electrolyzers according to claim 5, wherein the high power mode comprises: turning on a corresponding number of the second cells according to the number of the electrolyzers operating. valve, and start the alkali replenishing pump, the alkali liquor circulation pump, the heat exchange pump, and the heater. 9 . The thermal management system for a hydrogen production electrolyzer array according to claim 8 , wherein during the operation of the electrolyzer, it is continuously detected whether the lye temperature at the outlet of the lye circulating pump is higher than If the preset threshold is true, the heater is turned off. 10. The thermal management system for a hydrogen-producing electrolyzer array according to claim 8, wherein during the operation of the electrolyzer, it is continuously detected whether the lye temperature at the outlet of the lye circulating pump is higher than The temperature of the lye stored in the heat storage tank is lower than the preset threshold, and if so, the heat exchange pump is turned off.

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