An alkali liquid electrolyzer waste heat steam supply system and a steam supply method

Abstract

The present invention relates to the technical field of waste heat recovery of electrolyzers, and specifically relates to an alkali solution electrolyzer waste heat supply steam system and a steam supply method. The system includes a waste heat recovery module, a heat pump module, and a steam preparation and supply module. The waste heat recovery module includes an alkali solution electrolysis unit and a cooling unit, and the cooling unit is connected to the alkali solution electrolysis unit. The heat pump module includes a first power supply unit, a second power supply unit, an electric motor, and a compressor. The first power supply unit and the second power supply unit are respectively electrically connected to the electric motor, and the electric motor is connected to the compressor. The steam preparation and supply module includes a steam preparation unit and a steam supply unit, and the cooling unit and the steam preparation unit are respectively connected to the compressor. The present invention absorbs the waste heat of the alkali solution electrolyzer through a heat transfer working medium, compresses and heats it, and then heats the heat network feed water to evaporate it into high-temperature steam, so as to supply industrial steam users.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic cell waste heat recovery, in particular to an alkali liquid electrolytic cell waste heat steam supply system and a steam supply method. Background Art

[0002] In large-scale wind and solar hydrogen storage bases, green hydrogen produced from clean electricity generated by wind power and photovoltaics can be used as clean fuel to supply road transportation, ships, aerospace, etc. It can also be used as raw material to produce chemical products such as methanol, ammonia, methane, etc. It can also be used as energy storage to balance and regulate the power system.

[0003] The alkaline liquid electrolyzer is currently the most mature technology route for hydrogen production by electrolysis of water, and is also the hydrogen production equipment commonly configured in wind and solar hydrogen storage bases. This equipment will continue to consume electricity during the process of hydrogen production by electrolysis of water, causing the temperature of the electrolysis reaction zone to gradually rise. In order to ensure the efficient operation of the electrolyzer, the excess heat needs to be taken away by cooling water to maintain the temperature of the electrolysis reaction zone. However, the heat taken away by this part of the cooling water is usually eventually dissipated into the environment through the air-cooled cooler, resulting in a large amount of heat waste. Summary of the invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide an alkali liquid electrolyzer waste heat steam supply system and a steam supply method to solve the problem of a large amount of heat waste in the prior art of water electrolysis hydrogen production because the waste heat taken away by the cooling water in the electrolyzer is dissipated into the environment through air cooling.

[0005] The invention discloses a lye electrolytic cell waste heat steam supply system, comprising:

[0006] A waste heat recovery module, comprising an alkaline liquid electrolysis unit and a cooling unit, wherein cooling water is provided in the alkaline liquid electrolysis unit, a heat exchange medium is provided in the cooling unit, and the cooling unit is connected to the alkaline liquid electrolysis unit, so that the cooling water is introduced into the cooling unit to heat the heat exchange medium;

[0007] A heat pump module, comprising a first power supply unit, a second power supply unit, a motor and a compressor, wherein the first power supply unit and the second power supply unit are electrically connected to the motor respectively, the first power supply unit outputs green electricity and photovoltaic abandoned electricity, the second power supply unit outputs electrochemical energy storage, the motor is connected to the compressor, and the compressor is connected to the cooling unit, so that the heat exchange medium heated in the cooling unit is introduced into the compressor for compression and heating;

[0008] The steam preparation and supply module includes a steam preparation unit and a steam supply unit. The steam preparation unit is connected to the compressor so that the heat exchange working medium after compression and heating is introduced into the steam preparation unit. The steam preparation unit is connected to the steam supply unit so that the heat network feed water from the outlet of the steam supply unit is introduced into the steam preparation unit and heated and evaporated by the heat exchange working medium to generate industrial steam, which is then output to the steam supply unit. The steam preparation unit is also connected to the cooling unit so that the heat exchange working medium cooled in the steam preparation unit circulates back to the cooling unit and is heated by the cooling water of the alkaline electrolysis unit.

[0009] Optionally, a first circulation unit is provided between the alkaline electrolysis unit and the cooling unit. The first circulation unit includes a first delivery pipeline and a first return pipeline. The first delivery pipeline connects the alkaline electrolysis unit and the cooling unit and is used to introduce the cooling water in the alkaline electrolysis unit into the cooling unit. The first return pipeline connects the alkaline electrolysis unit and the cooling unit and is used to return the cooling water after heat exchange in the cooling unit to the alkaline electrolysis unit. A first booster pump is provided on the first return pipeline.

[0010] Optionally, a second circulation unit is provided between the steam preparation unit and the steam supply unit. The second circulation unit includes a second delivery pipeline and a second return pipeline. The second delivery pipeline connects the steam preparation unit and the steam supply unit and is used to transport the heat network feed water from the outlet of the steam supply unit to the steam preparation unit. A second booster pump is provided on the second delivery pipeline. The second return pipeline connects the steam preparation unit and the steam supply unit and is used to supply the industrial steam prepared by the steam preparation unit back to the steam supply unit.

[0011] Optionally, the first power supply unit includes a main power grid, a transformer, and a first circuit breaker. The main power grid outputs green electricity and photovoltaic curtailment electricity, and the main power grid, the transformer, the first circuit breaker, and the motor are connected in sequence.

[0012] Optionally, the second power supply unit includes an electrochemical energy storage device and a second circuit breaker. The electrochemical energy storage device outputs the electrochemically stored electrical energy, and the electrochemical energy storage device, the second circuit breaker, and the motor are connected in sequence.

[0013] Optionally, the heat pump module further includes a heat recovery unit. The cooling unit is connected to the compressor through the heat recovery unit, so that after the heat exchange working medium heated in the cooling unit passes through the heat recovery unit, it is introduced into the compressor. The steam preparation unit is connected to the cooling unit through the heat recovery unit, so that after the heat exchange working medium cooled in the steam preparation unit passes through the heat recovery unit, it heats the heat exchange working medium introduced from the cooling unit and is then led back into the cooling unit.

[0014] Optionally, a first rising pipeline is connected between the cooling unit and the heat recovery unit, a second rising pipeline is connected between the heat recovery unit and the compressor, and a third rising pipeline is connected between the compressor and the steam preparation unit, so that the heat exchange working medium heated in the cooling unit is sequentially introduced into the steam preparation unit through the first rising pipeline, the second rising pipeline, and the third rising pipeline;

[0015] A cooling pipeline is connected between the steam preparation unit and the heat recovery unit, so that the heat exchange working medium cooled in the steam preparation unit is introduced into the heat recovery unit through the cooling pipeline.

[0016] Optionally, the heat pump module further includes an expander. The expander is coaxially connected to the drive shaft of the compressor and is connected to the drive end of the motor;

[0017] The heat recovery unit is connected to the cooling unit through the expander, so that after the heat exchange working medium cooled in the heat recovery unit is introduced into the expander to do work, it is introduced into the cooling unit.

[0018] Optionally, a working pipeline is connected between the heat recovery unit and the expander, and a fourth rising pipeline is connected between the expander and the cooling unit, so that the heat exchange working medium cooled in the heat recovery unit is led back into the cooling unit sequentially through the working pipeline and the fourth rising pipeline.

[0019] The present invention also provides a steam supply method, which adopts the above-mentioned lye electrolytic cell waste heat steam supply system. The steam supply method includes:

[0020] In response to the operation of the lye electrolytic unit, the cooling water in the lye electrolytic unit is pressurized and introduced into the cooling unit, and the heat exchange working medium in the cooling unit is heated. The heat-exchanged cooling water returns to the lye electrolytic unit;

[0021] The heat-absorbing heat exchange working medium in the cooling unit is introduced into the compressor for compression and reheating until it is heated to a preset temperature;

[0022] Introduce the heated heat transfer working fluid in the compressor into the steam preparation unit, and introduce the heat network feed water in the steam supply unit into the steam preparation unit until the introduced heat network feed water is heated and evaporated by the introduced heat transfer working fluid to generate industrial steam at a preset temperature;

[0023] Output the generated industrial steam to the steam supply unit, and introduce the cooled heat transfer working fluid in the steam preparation unit back into the cooling unit to continue absorbing heat.

[0024] Compared with the prior art, the beneficial effects of the lye electrolytic cell waste heat supply steam system and steam supply method provided by the embodiments of the present invention are as follows:

[0025] By setting up a waste heat recovery module, a heat pump module, and a steam preparation and supply module, the heat transfer working fluid in the cooling unit is used to absorb the waste heat generated by the hydrogen production reaction in the lye electrolytic unit, and the compressor is used to compress and heat the heat transfer working fluid after heat absorption to form a high-pressure gas not lower than the preset temperature. Then, the high-pressure gas formed by compression and heating is introduced into the steam preparation unit to heat and evaporate the heat network feed water at the outlet of the steam supply unit into high-temperature steam to meet the steam demand of the steam supply unit, so as to supply industrial steam users. At the same time, the electric power of the motor driving the compressor is jointly provided by green electricity, photovoltaic abandoned electricity, and an electrochemical energy storage device, effectively solving the problem that the lye electrolytic unit, steam supply unit, etc. cannot withstand frequent start and stop. Thus, the waste heat, green electricity, etc. in the wind-solar-hydrogen energy storage base are fully utilized to provide high-value-added industrial steam, avoiding a large amount of waste of the waste heat of the electrolytic cell and greatly improving the economic benefits of the base. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The technical solutions of the present invention will be further described in detail below with reference to the drawings and embodiments. In the drawings:

[0027] Figure 1 is a schematic block diagram of the overall structure of the lye electrolytic cell waste heat supply steam system provided by the embodiment of the present invention.

[0028] Each reference numeral in the figure is:

[0029] 1. Waste heat recovery module; 11. Alkaline solution electrolysis unit; 12. Cooling unit; 13. First conveying pipeline; 14. First reflux pipeline; 15. First booster pump; 2. First power supply unit; 21. Main power grid; 22. Transformer; 23. First circuit breaker; 3. Second power supply unit; 31. Electrochemical energy storage device; 32. Second circuit breaker; 4. Motor; 5. Compressor; 51. Third boosting pipeline; 6. Steam preparation and supply module; 61. Steam preparation unit; 62. Steam supply unit; 63. Second conveying pipeline; 64. Second reflux pipeline; 65. Second booster pump; 7. Regenerative heating unit; 71. First boosting pipeline; 72. Second boosting pipeline; 73. Cooling pipeline; 8. Expander; 81. Work pipeline; 82. Fourth boosting pipeline. Detailed implementation mode

[0030] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. Now, in combination with the accompanying drawings, the preferred embodiments of the present invention will be described in detail.

[0031] The present invention discloses a waste heat supply steam system for an alkaline solution electrolyzer, including a waste heat recovery module 1, a heat pump module, and a steam preparation and supply module 6. The waste heat recovery module 1 includes an alkaline solution electrolysis unit 11 and a cooling unit 12. Cooling water is provided in the alkaline solution electrolysis unit 11, and a heat exchange working medium is provided in the cooling unit 12. The cooling unit 12 is connected to the alkaline solution electrolysis unit 11 for introducing the cooling water into the cooling unit 12 to heat the heat exchange working medium. The heat pump module includes a first power supply unit 2, a second power supply unit 3, a motor 4, and a compressor 5. The first power supply unit 2 and the second power supply unit 3 are respectively electrically connected to the motor 4. The first power supply unit 2 outputs green power and photovoltaic abandoned power, and the second power supply unit 3 outputs electrochemical energy storage. The motor 4 is connected to the compressor 5, and the compressor 5 is connected to the cooling unit 12, so that the heated heat exchange working medium in the cooling unit 12 is introduced into the compressor 5 for compression heating. The steam preparation and supply module 6 includes a steam preparation unit 61 and a steam supply unit 62. The steam preparation unit 61 is connected to the compressor 5, so that the compressed and heated heat exchange working medium is introduced into the steam preparation unit 61. The steam preparation unit 61 is connected to the steam supply unit 62, so that the heat network feed water from the outlet of the steam supply unit 62 is introduced into the steam preparation unit 61 to be heated and evaporated by the heat exchange working medium to generate industrial steam, and is output to the steam supply unit 62. The steam preparation unit 61 is also connected to the cooling unit 12, so that the cooled heat exchange working medium in the steam preparation unit 61 circulates back to the cooling unit 12 and is heated by the low-temperature water of the alkaline solution electrolysis unit 11.

[0032] Through the implementation of the above-mentioned embodiment of the waste heat supply steam system for the alkaline electrolyzer, the waste heat recovery module 1, the heat pump module, and the steam preparation and supply module 6 are set. The alkaline electrolysis unit 11 is an existing alkaline electrolysis device in the wind-solar-hydrogen storage base. Since the temperature of the electrolysis reaction zone gradually rises during the electrolytic water hydrogen production in the alkaline electrolysis unit 11, the cooling water provided in the alkaline electrolysis unit 11 is used to absorb the waste heat of the electrolysis reaction zone. And the cooling water that absorbs the waste heat is introduced into the cooling unit 12 to heat the heat transfer working medium in the cooling unit 12, so as to fully absorb the waste heat generated by the hydrogen production reaction in the alkaline electrolysis unit 11. At this time, the waste heat of the electrolysis reaction zone is transferred from the cooling water to the heat transfer working medium, and at this time the heat transfer working medium is low-grade heat energy. Then, the heated heat transfer working medium is compressed and reheated by the compressor 5 to form a high-pressure gas not lower than the preset temperature. Preferably, the heat transfer working medium is lifted to a high-pressure gas not lower than 320 °C in the compressor 5. Thus, by introducing the high-pressure gas formed by compression heating into the steam preparation unit 61, the heat network feed water at the outlet of the steam supply unit 62 is heated and evaporated into high-temperature steam to meet the steam demand of the steam supply unit 62, so as to supply industrial steam users. Preferably, since the heat transfer working medium is lifted to a high-pressure gas not lower than 320 °C, the heat network feed water can be heated and evaporated into steam at about 300 °C at this time to supply industrial steam users. Since generally a chemical plant using hydrogen as a raw material will be synchronously equipped around a large-scale wind-solar-hydrogen storage base, this chemical plant usually has a large demand for industrial steam at about 300 °C. Therefore, the embodiment of the present invention can provide high-value-added industrial steam. In addition, the electric power of the motor 4 driving the compressor 5 is jointly provided by green power, photovoltaic curtailment, and the electrochemical energy storage device 31. That is, generally, the first power supply unit 2 provides the wind power and photovoltaic curtailment in the wind-solar-hydrogen storage base to provide electric power for the motor 4; when there is no wind power and photovoltaic curtailment, the second power supply unit 3 provides the electrochemical energy storage in the wind-solar-hydrogen storage base to provide electric power for the motor 4. Through the joint power supply of the first power supply unit 2 and the second power supply unit 3, the problems that the alkaline electrolysis unit 11, the steam supply unit 62, etc. cannot withstand frequent start and stop are effectively solved, and the efficiency of compressing and heating the heat transfer working medium to a high-temperature gas can be improved to improve the steam preparation efficiency of the steam system. Among them, the steam supply unit 62 is an industrial steam demand user, generally a chemical plant synchronously equipped around the wind-solar-hydrogen storage base using hydrogen as a raw material, and its chemical process usually cannot withstand frequent start and stop. Thus, the waste heat of the alkaline electrolyzer and green power in the wind-solar-hydrogen storage base are fully utilized to provide high-value-added industrial steam, avoiding a large amount of waste of the electrolyzer waste heat, and greatly improving the economic benefits of the base. Preferably, the cooling unit 12 is a cooler, and the steam preparation unit 61 is a steam generator.

[0033] Preferably, in the embodiments of the present invention, the heat exchange working medium may be air, carbon dioxide, argon, helium, nitrogen, etc. Different heat exchange working media have different coefficients of performance (COP); for the waste heat utilization temperature range of 80°C to 65°C of the alkaline solution electrolyzer, industrial steam at about 300°C is provided, and the COP is about 1.1 to 1.5.

[0034] Furthermore, a first circulation unit is provided between the alkaline solution electrolysis unit 11 and the cooling unit 12. The first circulation unit includes a first delivery pipeline 13 and a first return pipeline 14. The first delivery pipeline 13 connects the alkaline solution electrolysis unit 11 and the cooling unit 12 and is used to introduce the cooling water in the alkaline solution electrolysis unit 11 into the cooling unit 12. The first return pipeline 14 connects the alkaline solution electrolysis unit 11 and the cooling unit 12 and is used to return the heat-exchanged cooling water in the cooling unit 12 to the alkaline solution electrolysis unit 11. A first booster pump 15 is provided on the first return pipeline 14.

[0035] Through the implementation of the above embodiments of the waste heat steam supply system of the alkaline solution electrolyzer, the cooling water that absorbs the waste heat of the electrolyzer in the alkaline solution electrolysis unit 11 can be transported to the cooling unit 12 by using the first delivery pipeline 13, and the cooling water heat-exchanged with the heat exchange working medium in the cooling unit 12 can be led back into the alkaline solution electrolysis unit 11 to continue absorbing the waste heat of the electrolyzer by using the first return pipeline 14, so that the first delivery pipeline 13 and the first return pipeline 14 form a first heat exchange loop for the cooling water, so as to realize the repeated and continuous absorption of the waste heat of the alkaline solution electrolyzer, thereby making full use of the waste heat of the alkaline solution electrolyzer. By setting the first booster pump 15, the flow pressure of the first heat exchange loop can be increased, so as to pressurize and transport the cooling water that absorbs the waste heat of the electrolyzer in the alkaline solution electrolysis unit 11 to the cooling unit 12 for heat exchange, thereby improving the heat exchange efficiency of the cooling unit 12.

[0036] Furthermore, a second circulation unit is provided between the steam preparation unit 61 and the steam supply unit 62. The second circulation unit includes a second delivery pipeline 63 and a second return pipeline 64. The second delivery pipeline 63 connects the steam preparation unit 61 and the steam supply unit 62 and is used to transport the heating network feed water at the outlet of the steam supply unit 62 into the steam preparation unit 61. A second booster pump 65 is provided on the second delivery pipeline 63. The second return pipeline 64 connects the steam preparation unit 61 and the steam supply unit 62 and is used to supply the industrial steam prepared by the steam preparation unit 61 back to the steam supply unit 62.

[0037] Through the implementation of the above-described embodiment of the waste heat steam supply system for the alkaline electrolyzer, the hot water supply for the heat network at the outlet of the steam supply unit 62 can be transported into the steam preparation unit 61 by using the second delivery pipeline 63, and the industrial steam prepared by the steam preparation unit 61 can be supplied back to the steam supply unit 62 by using the second return pipeline 64 to be provided to the hydrogen-based chemical plant surrounding the wind-solar-hydrogen energy storage base. This enables the second delivery pipeline 63 and the second return pipeline 64 to form a second heat exchange loop for the hot water supply for the heat network and steam, so as to repeatedly heat and evaporate the hot water supply for the heat network at the outlet of the steam supply unit 62 to continuously prepare high-temperature steam that meets the requirements. By setting the second booster pump 65, the industrial steam prepared by the steam preparation unit 61 can be pressurized and transported to the steam supply unit 62 to overcome the pipeline resistance by increasing the steam transportation pressure to ensure the stability and continuity of steam supply.

[0038] Furthermore, the first power supply unit 2 includes the main power grid 21, a transformer 22, and a first circuit breaker 23. The main power grid 21 outputs green power and PV curtailment power, and the main power grid 21, the transformer 22, the first circuit breaker 23, and the motor 4 are connected in sequence.

[0039] Furthermore, the second power supply unit 3 includes an electrochemical energy storage device 31 and a second circuit breaker 32. The electrochemical energy storage device 31 outputs the electrochemically stored electrical energy, and the electrochemical energy storage device 31, the second circuit breaker 32, and the motor 4 are connected in sequence.

[0040] Through the implementation of the above-described embodiment of the waste heat supply steam system of the alkaline electrolyzer, the first power supply unit 2 accesses green power and photovoltaic curtailment power through the main power grid 21 of the power grid, realizing the diversified supply of energy. Green power refers to the electricity from renewable energy sources in the wind-solar-hydrogen storage base, such as wind energy, solar energy, etc., while photovoltaic curtailment power refers to the electricity that is not utilized in time due to the excess of solar photovoltaic power generation. This configuration helps to reduce the dependence on traditional fossil fuels, lower carbon emissions, and support sustainable development. At the same time, the utilization of photovoltaic curtailment power avoids the waste of electricity and improves the energy utilization efficiency. The electrochemical energy storage device 31 in the second power supply unit 3 can store electrical energy and release it when needed, which helps to smooth the load fluctuations of the power system in the wind-solar-hydrogen storage base and optimize the dispatching of the power system. The first circuit breaker 23 and the second circuit breaker 32, as protection devices, can quickly cut off the circuit in case of short circuit or overload, protect the safety of system equipment and personnel, and switch between the first power supply unit 2 and the second power supply unit 3. That is, when the first circuit breaker 23 and the second circuit breaker 32 are closed simultaneously, the first power supply unit 2 and the second power supply unit 3 can supply power together. It is also possible to only close the first circuit breaker 23, and the first power supply unit 2 provides wind power and photovoltaic curtailment power in the wind-solar-hydrogen storage base to provide electric power for the motor 4; when there is no wind power and photovoltaic curtailment power, then close the second circuit breaker 32, and the second power supply unit 3 provides the electrochemical energy storage in the wind-solar-hydrogen storage base to provide electric power for the motor 4. Thus, the configuration of the first power supply unit 2 and the second power supply unit 3 provides dual power supply guarantees. Even when a fault occurs or the power supply is unstable in the main power grid 21, the electrochemical energy storage device 31 can provide backup power to ensure the continuous operation of equipment such as the motor 4 and the compressor 5. Furthermore, the electric energy in the wind-solar-hydrogen storage base is fully utilized, enhancing the economic benefits of the base. And the whole process does not use fossil fuels, having significant environmental benefits, conforming to the relevant policies of green power to produce hydrogen, ammonia, and alcohol, and can enjoy corresponding subsidies in the final products.

[0041] Furthermore, the heat pump module further includes a heat recovery unit 7. The cooling unit 12 is connected to the compressor 5 through the heat recovery unit 7, so that the heated heat transfer medium in the cooling unit 12 is introduced into the compressor 5 after passing through the heat recovery unit 7. The steam preparation unit 61 is connected to the cooling unit 12 through the heat recovery unit 7, so that the cooled heat transfer medium in the steam preparation unit 61 passes through the heat recovery unit 7, heats the heat transfer medium introduced from the cooling unit 12, and then is led back into the cooling unit 12.

[0042] Further, a first upgrading pipeline 71 is connected between the cooling unit 12 and the heat recovery unit 7, a second upgrading pipeline 72 is connected between the heat recovery unit 7 and the compressor 5, and a third upgrading pipeline 51 is connected between the compressor 5 and the steam preparation unit 61, so that the heated heat transfer working medium in the cooling unit 12 is introduced into the steam preparation unit 61 successively through the first upgrading pipeline 71, the second upgrading pipeline 72 and the third upgrading pipeline 51. A cooling pipeline 73 is connected between the steam preparation unit 61 and the heat recovery unit 7, so that the cooled heat transfer working medium in the steam preparation unit 61 is introduced into the heat recovery unit 7 through the cooling pipeline 73.

[0043] Through the implementation of the above embodiment of the lye electrolyzer waste heat supply steam system, by virtue of the setting of the heat recovery unit 7, since the heat transfer working medium is first compressed and heated to a high temperature by the compressor 5 and then enters the steam preparation unit 61 to heat and evaporate the heat network feed water. Therefore, the heat transfer working medium after heat exchange in the steam preparation unit 61 still has low-temperature heat. The heat transfer working medium after heat exchange in the steam preparation unit 61 is introduced into the heat recovery unit 7 by using the cooling pipeline 73. At the same time, before the heat transfer working medium after absorbing heat in the cooling unit 12 enters the compressor 5, it is first introduced into the heat recovery unit 7 by using the first upgrading pipeline 71, so that in the heat recovery unit 7, the heat transfer working medium introduced from the steam preparation unit 61 heats the heat transfer working medium introduced from the cooling unit 12, so as to make full use of the low-temperature heat of the heat transfer working medium at the outlet of the steam preparation unit 61, thereby further recovering heat to improve the cycle efficiency and heat utilization efficiency of the system. At this time, there are two working medium flow channels for heat exchange in the heat recovery unit 7, so that the heated heat transfer working medium enters the compressor 5 through the second upgrading pipeline 72, and the heat transfer working medium compressed and heated in the compressor 5 is introduced into the steam preparation unit 61 through the third upgrading pipeline 51. And the heat transfer working medium cooled in the heat recovery unit 7 flows to the cooling unit 12. Through the setting of each pipeline in the system, it helps to optimize the heat exchange process, and improves the heat exchange efficiency through reasonable fluid paths and pressure control.

[0044] Further, the heat pump module further includes an expander 8, the expander 8 is coaxially connected to the drive shaft of the compressor 5, and the expander 8 is connected to the drive end of the motor 4;

[0045] The heat recovery unit 7 is connected to the cooling unit 12 through the expander 8, so that the cooled heat transfer working medium in the heat recovery unit 7 is introduced into the expander 8 to do work and then introduced into the cooling unit 12.

[0046] Further, a working pipeline 81 is connected between the heat recovery unit 7 and the expander 8, and a fourth upgrading pipeline 82 is connected between the expander 8 and the cooling unit 12, so that the cooled heat transfer working medium in the heat recovery unit 7 is introduced back into the cooling unit 12 successively through the working pipeline 81 and the fourth upgrading pipeline 82.

[0047] Through the implementation of the above-mentioned embodiment of the waste heat supply steam system of the alkaline solution electrolyzer, by setting the expander 8, the heat exchange working medium cooled in the regenerative unit 7 enters the expander 8 through the work pipeline 81 to do further work, further recovering the thermal energy and pressure potential energy in the heat exchange working medium, so that the thermal energy in the whole system is fully utilized. And by coaxially connecting the drive shafts of the expander 8 and the compressor 5, the expander 8 recovers the thermal energy and pressure potential energy of the heat exchange working medium, which is converted into shaft power and provided to the compressor 5. The expander 8 is connected to the motor 4, so that the shaft power of the compressor 5 is jointly provided by the expander 8 and the motor 4. Thus, the shaft power provided by the expander 8 can effectively reduce the electric power that the motor 4 needs to provide. Without changing the steam preparation efficiency, the thermal energy in the system is fully utilized to reduce the electric power that the motor 4 needs to provide, greatly reducing the power consumption, lowering the operation cost, and enabling the system to convert thermal energy into useful work more efficiently, thereby improving the overall energy efficiency. After the heat exchange working medium finishes doing work in the expander 8, it enters the cooling unit 12 through the fourth upgrading pipeline 82 to continue heat exchange with the cooling water that has absorbed the waste heat of the alkaline solution electrolyzer, thus completing the whole cycle.

[0048] The present invention also provides a steam supply method, which adopts the above-mentioned waste heat supply steam system of the alkaline solution electrolyzer. The steam supply method includes:

[0049] In response to the operation of the alkaline solution electrolysis unit 11, the cooling water in the alkaline solution electrolysis unit 11 is pressurized and introduced into the cooling unit 12, and the heat exchange working medium in the cooling unit 12 is heated. The cooled cooling water returns to the alkaline solution electrolysis unit 11;

[0050] The heat-absorbing heat exchange working medium in the cooling unit 12 is introduced into the compressor 5 for compression and reheating until it is heated to a preset temperature;

[0051] The heat exchange working medium heated in the compressor 5 is introduced into the steam preparation unit 61, and the heat network feed water in the steam supply unit 62 is introduced into the steam preparation unit 61 until the introduced heat network feed water is heated and evaporated by the introduced heat exchange working medium to generate industrial steam at a preset temperature;

[0052] The generated industrial steam is output to the steam supply unit 62, and the cooled heat exchange working medium in the steam preparation unit 61 is led back to the cooling unit 12 to continue absorbing heat.

[0053] Through the implementation of the above embodiments of the steam supply method, after the heat exchange working medium recovers the waste heat of the alkaline electrolyzer module in the cooling unit 12, it enters the compressor 5 for compression. At this time, green electricity and photovoltaic abandoned electricity, or electrochemical electrical energy start the compressor 5 through the motor 4, convert the heat exchange working medium into high-grade heat energy, and transport it to the steam preparation unit 61, so that the heat network feed water coming from the steam supply unit 62 exchanges heat with the heat exchange working medium in the steam preparation unit 61, is evaporated into steam at about 300 °C, and is supplied to steam users. Thus, the waste heat of the alkaline electrolyzer and green electricity in the wind-solar-hydrogen storage base are fully utilized to provide high-value-added industrial steam, avoiding a large amount of waste of electrolyzer waste heat, and greatly improving the economic benefits of the base.

[0054] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting it. For those skilled in the art, the technical solutions recorded in the above embodiments can be modified, or some of the technical features can be equivalently replaced; and all such modifications and replacements should belong to the protection scope of the present invention.

Claims

1. A waste heat steam supply system for an alkali liquid electrolyzer, characterized in that: The alkali liquid electrolyzer waste heat steam supply system comprises: A waste heat recovery module, comprising an alkaline liquid electrolysis unit and a cooling unit, wherein cooling water is provided in the alkaline liquid electrolysis unit, a heat exchange medium is provided in the cooling unit, and the cooling unit is connected to the alkaline liquid electrolysis unit, so that the cooling water is introduced into the cooling unit to heat the heat exchange medium; A heat pump module, comprising a first power supply unit, a second power supply unit, a motor and a compressor, wherein the first power supply unit and the second power supply unit are electrically connected to the motor respectively, the first power supply unit outputs green electricity and photovoltaic abandoned electricity, the second power supply unit outputs electrochemical energy storage, the motor is connected to the compressor, and the compressor is connected to the cooling unit, so that the heat exchange medium heated in the cooling unit is introduced into the compressor for compression and heating; The first power supply unit includes a main power grid, a transformer and a first circuit breaker, the main power grid outputs green power and photovoltaic abandoned power, and the main power grid, the transformer, the first circuit breaker and the motor are connected in sequence; The second power supply unit includes an electrochemical energy storage device and a second circuit breaker, the electrochemical energy storage device outputs stored electrochemical reaction electric energy, and the electrochemical energy storage device, the second circuit breaker and the motor are connected in sequence; a steam preparation and supply module includes a steam preparation unit and a steam supply unit, the steam preparation unit is connected to the compressor so that the compressed and heated heat exchange medium is introduced into the steam preparation unit, the steam preparation unit is connected to the steam supply unit so that the hot network feed water from the outlet of the steam supply unit is introduced into the steam preparation unit and evaporated by the heat exchange medium to generate industrial steam, and output to the steam supply unit, the steam preparation unit is also connected to the cooling unit so that the heat exchange medium cooled in the steam preparation unit is circulated back to the cooling unit and heated by the low-temperature water of the alkaline liquid electrolysis unit; The heat pump module further includes a heat recovery unit, and the cooling unit is connected to the compressor through the heat recovery unit, so that the heat exchange medium heated in the cooling unit is introduced into the compressor after passing through the heat recovery unit, and the steam preparation unit is connected to the cooling unit through the heat recovery unit, so that the heat exchange medium cooled in the steam preparation unit passes through the heat recovery unit, and the heat exchange medium introduced from the cooling unit is heated before being introduced back into the cooling unit; The heat pump module further comprises an expander, the expander is coaxially connected to the drive shaft of the compressor, and the expander is connected to the drive end of the motor; The heat recovery unit is connected to the cooling unit through the expander, so that the heat exchange medium cooled in the heat recovery unit is introduced into the expander to perform work and then introduced into the cooling unit.

2. The alkali liquid electrolytic cell waste heat steam supply system according to claim 1, characterized in that: A first circulation unit is arranged between the alkaline liquid electrolysis unit and the cooling unit, and the first circulation unit includes a first delivery pipeline and a first reflux pipeline. The first delivery pipeline connects the alkaline liquid electrolysis unit and the cooling unit, and is used to introduce the cooling water in the alkaline liquid electrolysis unit into the cooling unit. The first reflux pipeline connects the alkaline liquid electrolysis unit and the cooling unit, and is used to return the cooling water after heat exchange in the cooling unit to the alkaline liquid electrolysis unit. A first booster pump is arranged on the first reflux pipeline.

3. The alkali liquid electrolytic cell waste heat steam supply system according to claim 1, characterized in that: A second circulation unit is arranged between the steam preparation unit and the steam supply unit, and the second circulation unit includes a second delivery pipeline and a second return pipeline. The second delivery pipeline connects the steam preparation unit and the steam supply unit, and is used to deliver the hot network feed water at the outlet of the steam supply unit to the steam preparation unit. A second booster pump is arranged on the second delivery pipeline, and the second return pipeline connects the steam preparation unit and the steam supply unit, and is used to supply the industrial steam prepared by the steam preparation unit back to the steam supply unit.

4. The alkali liquid electrolytic cell waste heat steam supply system according to claim 1, characterized in that: A first product upgrading pipeline is connected between the cooling unit and the heat recovery unit, a second product upgrading pipeline is connected between the heat recovery unit and the compressor, and a third product upgrading pipeline is connected between the compressor and the steam preparation unit, so that the heat exchange medium heated in the cooling unit is introduced into the steam preparation unit through the first product upgrading pipeline, the second product upgrading pipeline and the third product upgrading pipeline in sequence; A cooling pipeline is connected between the steam preparation unit and the heat recovery unit, so that the heat exchange medium cooled in the steam preparation unit is introduced into the heat recovery unit through the cooling pipeline.

5. The alkali liquid electrolytic cell waste heat steam supply system according to claim 4, characterized in that: A working pipeline is connected between the heat recovery unit and the expander, and a fourth product upgrading pipeline is connected between the expander and the cooling unit, so that the heat exchange medium cooled in the heat recovery unit is led back to the cooling unit through the working pipeline and the fourth product upgrading pipeline in sequence.

6. A steam supply method, using the alkali liquid electrolytic cell waste heat steam supply system according to any one of claims 1 to 5, characterized in that: The steam supply method comprises: In response to the operation of the alkaline liquid electrolysis unit, the cooling water in the alkaline liquid electrolysis unit is introduced into the cooling unit under pressure, and the heat exchange medium in the cooling unit is heated, and the cooling water after heat exchange is returned to the alkaline liquid electrolysis unit; Introducing the heat exchange medium that absorbs heat in the cooling unit into the compressor for compression and reheating until it is heated to a preset temperature; Introducing the heat exchange medium heated in the compressor into the steam preparation unit, and introducing the hot network feed water in the steam supply unit into the steam preparation unit, until the introduced hot network feed water is heated and evaporated by the introduced heat exchange medium to generate industrial steam at a preset temperature; The generated industrial steam is output to the steam supply unit, and the heat exchange medium cooled in the steam preparation unit is introduced back to the cooling unit to continue absorbing heat.

Images