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CN-121976209-A - Water electrolysis hydrogen production system based on photovoltaic waste heat recovery and heat pump and operation method thereof

CN121976209ACN 121976209 ACN121976209 ACN 121976209ACN-121976209-A

Abstract

The invention provides a water electrolysis hydrogen production system based on photovoltaic waste heat recovery and a heat pump and an operation method thereof, belonging to the technical fields of solar energy utilization technology, heat pump heating technology and water electrolysis hydrogen production. The system comprises a photovoltaic and photo-thermal integrated system, a heat pump system, a PEM water electrolysis hydrogen production system and an electric energy management system. The photovoltaic and photo-thermal integrated system collects low-grade waste heat on the back of the photovoltaic panel while generating electricity, the heat pump system absorbs the waste heat through refrigerating working media flowing through the back of the photovoltaic panel and improves the grade of heat energy by utilizing a compressor, so that circulating hot water with stable temperature is provided for a PEM (PEM) electrolytic water hydrogen production system tank, and the heat pump system is regulated by a plurality of three-way valves and switches a single-stage or overlapping mode under different environment temperatures. The electric energy management system optimally distributes and stores photovoltaic electric energy and supplies power for the system. The invention realizes the efficient cooperation of photovoltaic power generation, waste heat recovery and electrolytic hydrogen production, improves the hydrogen energy conversion efficiency and ensures the stable operation of hydrogen production.

Inventors

  • JIA TENG
  • YAO XUE
  • WANG XINGNAN
  • TANG BAOZHU
  • HAO HAN
  • ZHU JIA

Assignees

  • 南京大学

Dates

Publication Date
20260505
Application Date
20251231

Claims (10)

  1. 1. The system is characterized by comprising a photovoltaic photo-thermal integrated system, a heat pump system, a PEM (PEM) water electrolysis hydrogen production system and an electric energy management system, wherein the photovoltaic photo-thermal integrated system is connected with a circuit through a thermal working medium flow channel; The photovoltaic and photo-thermal integrated system is used for simultaneously generating electric energy and recovering low-grade waste heat generated by a photovoltaic panel and comprises a PVT main body (1), wherein the PVT main body (1) comprises a photovoltaic panel and a runner integrated on the back of the photovoltaic panel, the runner is connected with a heat pump system to serve as an evaporator, and the low-grade waste heat in the power generation process of the photovoltaic panel is collected; the low-grade waste heat is processed into high-grade heat energy through the heat pump system and then is provided for the PEM electrolyzed water hydrogen production system; the heat pump system switches different operation modes according to the ambient temperature; the heat pump system comprises a heat storage condensing water tank (9); the PEM electrolytic water hydrogen production system produces hydrogen gas by water electrolysis and comprises a PEM electrolytic tank (11) connected with the heat storage condensing water tank (9); The electric energy management system is arranged between the photovoltaic photo-thermal integrated system and the PEM water electrolysis hydrogen production system and the heat pump system, is connected with the photovoltaic photo-thermal integrated system and the PEM water electrolysis hydrogen production system and the heat pump system through circuits, and is used for managing, distributing and storing photovoltaic electric energy so as to supply power to the water electrolysis hydrogen production system based on photovoltaic waste heat recovery and the heat pump and maintain stable operation of the hydrogen production process.
  2. 2. The system for producing hydrogen by electrolysis of water based on recovery of waste heat from photovoltaic and heat pump according to claim 1, wherein the heat pump system is equipped with a plurality of three-way valves to adjust the flow direction of working medium to regulate the operation mode of the heat pump system, The three-way valve is used for switching an operation mode according to the environment temperature system, wherein when the environment temperature is higher than a set value, the heat pump system is operated in a single-stage heat pump circulation mode; The set value is 5 ℃.
  3. 3. The system for producing hydrogen from electrolyzed water based on photovoltaic waste heat recovery and heat pump according to claim 2, characterized in that the heat pump system further comprises a water pump (10); the heat storage condensing water tank (9), the water pump (10) and the PEM electrolytic tank (11) are communicated through pipelines to form a circulating hot water loop; The heat storage condensing water tank (9) continuously provides circulating hot water with stable temperature for the PEM electrolytic tank (11) by utilizing the circulating hot water loop; A heat exchanger and a temperature sensor are arranged in the heat storage condensing water tank (9), The heat exchanger is used for heating the water temperature in the heat storage condensing water tank (9), The temperature sensor is used for monitoring the water temperature in the heat storage condensing water tank (9) so as to feed back and control the running state of the heat pump system; The heat storage condensing water tank (9) is a heat storage type hot water tank, and the heat storage condensing water tank is used for circulating hot water and storing heat through flow regulation of the water pump (10) so that the working temperature of the PEM electrolytic tank (11) is kept stable.
  4. 4. The system for producing hydrogen from electrolyzed water based on a photovoltaic waste heat recovery and heat pump according to claim 3, wherein the plurality of three-way valves comprises a first three-way valve (12), a second three-way valve (13), a third three-way valve (14) and a fourth three-way valve (15), The heat pump system further comprises a plurality of compressors, a plurality of expansion valves and a first heat exchanger (8), The compressor comprises a first compressor (4) and a second compressor (5); the expansion valve comprises a first expansion valve (7) and a second expansion valve (6); The pipeline led out of the PVT main body (1) is branched after passing through the first compressor (4) and the first three-way valve (12) in sequence, one pipeline enters the heat storage condensate water tank (9) through the second three-way valve (13), and the other pipeline is led into the first heat exchanger (8) and then compressed by the second compressor (5) and then is connected into the heat storage condensate water tank (9) through the second three-way valve (13); three ends of the third three-way valve (14) are respectively connected with one ends of the water storage condensate tank (9), the second expansion valve (6) and the fourth three-way valve (15); One end of the second expansion valve (6) is connected with the third three-way valve (14), and the other end of the second expansion valve is connected with the first heat exchanger (8); One end of the fourth three-way valve is connected with the third three-way valve (14), one of the other two ends is connected with the first heat exchanger (8), and the other end is connected with the PVT main body (1) through the first expansion valve (7).
  5. 5. The system for producing hydrogen by electrolysis of water based on photovoltaic waste heat recovery and heat pump according to claim 4, wherein the electric energy management system comprises an MPPT control system (2), an inverter (3) and an energy storage battery (16), The MPPT control system (2) is used for outputting electric energy and providing working current for the PEM electrolytic tank (11); the inverter (3) is used for converting partial direct current into alternating current and providing power for the compressor and the water pump (10); the energy storage battery (16) is used for storing surplus electric energy in the operation of the water electrolysis hydrogen production system based on the photovoltaic waste heat recovery and the heat pump, and supplying power to the PEM electrolytic tank (11) when the solar energy input is insufficient, so that the continuous and stable operation of the hydrogen production process is ensured; The circuit is divided into two paths after passing through the MPPT control system (2) from the photovoltaic and photo-thermal integrated system, wherein one path is respectively connected into the first compressor (4), the second compressor (5) and the water pump (10) after passing through the inverter (3), and the other path is respectively connected into the energy storage battery (16) and the PEM electrolytic tank (11); The energy storage cell (16) is electrically connected to the PEM electrolyzer (11).
  6. 6. The system for producing hydrogen by electrolyzing water based on the recovery of waste heat of photovoltaic and the heat pump according to claim 2, The photovoltaic panel is a solar battery pack for photovoltaic power generation, and the type of the solar battery pack comprises a crystalline silicon solar battery, a perovskite solar battery or an organic solar battery; The PEM electrolyzer (11) is internally provided with an electrolysis unit, a proton exchange membrane, an anode electrode plate, a cathode electrode plate and an end plate, and the circulating hot water loop is connected with the anode end of the PEM electrolyzer (11) and is used for maintaining the constant temperature operation of the PEM electrolyzer (11) and taking out the generated gas.
  7. 7. The system for producing hydrogen by electrolyzing water based on the recovery of waste heat of photovoltaic and the heat pump according to claim 4, The heat storage condensate water tank (9) is internally provided with a flowmeter (17) for monitoring the water quantity in the heat storage condensate water tank (9), and supplementing water when the water quantity in the heat storage condensate water tank is reduced to a set value.
  8. 8. A method of operating a photovoltaic waste heat recovery and heat pump based electrolyzed water hydrogen production system according to any of claims 1 to 7, When the ambient temperature is higher than 5 ℃, the water electrolysis hydrogen production system based on the photovoltaic waste heat recovery and the heat pump operates in a summer mode under the regulation and control of the MPPT control system (2) and the three-way valve; When the ambient temperature is lower than 5 ℃, the water electrolysis hydrogen production system based on the photovoltaic waste heat recovery and the heat pump is operated in a winter mode under the regulation and control of the MPPT control system (2) and the three-way valve.
  9. 9. The method for operating a water electrolysis hydrogen production system based on a photovoltaic waste heat recovery and heat pump according to claim 8, When operating in summer mode, the heat pump system adjusts to a single stage vapor compression heat pump mode; in the PVT main body (1), after the refrigerating working medium flowing in the flow channel at the back of the photovoltaic panel absorbs low-grade waste heat of the photovoltaic panel of the PVT main body (1), the low-grade waste heat is compressed into high-temperature high-pressure steam with the temperature not lower than 80 ℃ and the pressure not lower than 25 atmospheres by the first compressor (4); The obtained high-grade steam is led into a heat exchanger in the heat storage condensate water tank (9) through a first three-way valve (12) and a second three-way valve (13), and is subjected to heat exchange with water in the heat storage condensate water tank (9) to heat the water temperature; then, the working medium subjected to heat exchange is throttled and depressurized through a third three-way valve (13), a fourth three-way valve (15) and a first expansion valve (7), and flows back to a flow channel at the back of the photovoltaic panel to form a complete heat pump cycle; the heat pump system continuously removes waste heat of a photovoltaic panel of the photovoltaic and photo-thermal integrated system, so that the power generation efficiency of the photovoltaic and photo-thermal integrated system is improved, and meanwhile, heat energy is transferred to the heat storage condensate water tank (9); the heat storage condensing water tank (9) stores heat and drives hot water circulation through the water pump (10) to maintain the optimal working temperature of the PEM electrolytic tank (11), and meanwhile, a flowmeter (17) in the heat storage condensing water tank monitors the reduction of water quantity of the water tank and supplements water required by electrolysis according to the monitoring result; After the direct current generated by the photovoltaic photo-thermal integrated system is output and regulated by the MPPT control system (2), one part provides constant current for the PEM electrolytic tank (11), surplus electric energy is stored in the energy storage battery (16), and the other part is converted into alternating current through the inverter (3) to serve as the first compressor (4) and the water pump (10).
  10. 10. The method for operating a water electrolysis hydrogen production system based on a photovoltaic waste heat recovery and heat pump according to claim 8, When operating in winter mode, the heat pump system adjusts to a cascade vapor compression heat pump mode; In the PVT main body (1), after the refrigerating working medium flowing in the flow channel at the back of the photovoltaic panel absorbs low-grade waste heat of the photovoltaic panel of the PVT main body (1), the low-grade waste heat is compressed into high-grade steam with the temperature of not lower than 40 ℃ and the pressure of not lower than 10 atmospheres by a first compressor (4), and the high-grade steam is led into a first heat exchanger (8) through a first three-way valve (12); then, the working medium flowing out of the first heat exchanger (8) is compressed into high-temperature high-pressure steam with the temperature not lower than 80 ℃ and the pressure not lower than 25 barometric pressures through the second compressor (5), and the high-temperature high-pressure steam is led into the heat exchanger in the heat storage condensing water tank (9) through the second three-way valve (13) to exchange heat with water in the heat storage condensing water tank (9) so as to heat the water temperature; The working medium subjected to heat exchange is throttled and depressurized through a third three-way valve (14) and a second expansion valve (6), flows back to the first heat exchanger (8), throttled and depressurized through a fourth three-way valve (15) and the first expansion valve (7), and flows back to a runner at the back of the photovoltaic panel to form a two-stage complete heat pump cycle; The heat storage condensing water tank (9) drives hot water circulation through the water pump (10) to raise the water temperature and stably maintain the water temperature at the working temperature of the PEM electrolytic tank (11), and meanwhile, the flowmeter (17) in the heat storage condensing water tank (9) monitors the reduction of the water quantity of the heat storage condensing water tank (9) and supplements water required by electrolysis according to the monitoring result; After the direct current generated by the photovoltaic photo-thermal integrated system is output and regulated by the MPPT control system (2), one part provides constant current for the PEM electrolytic tank (11), surplus electric energy is stored in the energy storage battery (16), and the other part is converted into alternating current through the inverter (3) to supply power for the first compressor (4), the second compressor (5) and the water pump (10).

Description

Water electrolysis hydrogen production system based on photovoltaic waste heat recovery and heat pump and operation method thereof Technical Field The invention belongs to the technical fields of solar energy utilization technology, heat pump heat supply technology and water electrolysis hydrogen production, and particularly relates to a water electrolysis hydrogen production system based on photovoltaic waste heat recovery and a heat pump and an operation method thereof, in particular to a proton exchange membrane water electrolysis hydrogen production system based on photovoltaic waste heat recovery and a heat pump and an operation method thereof. Background The hydrogen energy is taken as a completely green and clean energy source, and has broad prospect in the fields of transportation, industrial processing, energy storage regulation and the like. However, the mainstream hydrogen production method still depends on fossil fuels, and has the outstanding problems of high energy consumption and high carbon emission, so that the development of low-carbon and renewable hydrogen production technology has become a key direction of energy transformation. Among the various green hydrogen production routes, water electrolysis technologies driven by renewable energy sources such as solar energy, wind energy and the like, particularly Proton Exchange Membrane (PEM) water electrolysis technologies, are considered to have the potential of near zero carbon emission. However, this type of technology still faces multiple challenges in practical applications: On one hand, renewable energy sources have intermittence and volatility, which easily cause unstable current, voltage overshoot and partial load efficiency reduction of the electrolytic cell to influence the overall energy efficiency and equipment life of the system, and on the other hand, PEM electrolytic cells are extremely sensitive to the running temperature, the high-efficiency working range of the PEM electrolytic cell is usually between 60 and 80 ℃, and the existing system generally lacks a high-efficiency and accurate heat management scheme matched with the PEM electrolytic cell, so that the temperature stability is difficult to maintain, and the improvement of the hydrogen production efficiency is limited. In the prior art, an electric heating or conventional heat exchange device is adopted to supply heat for the electrolytic tank, so that the system has high energy consumption and low comprehensive energy efficiency. In addition, the scheme tries to directly couple the photovoltaic power generation with the PEM electrolytic tank and supply heat energy in a photovoltaic power generation-electric heating mode, but the solar energy utilization rate is low and the conversion efficiency from solar energy to hydrogen energy is still low because the conversion efficiency from electricity to heat is low and the waste heat in the power generation process of the photovoltaic panel is not effectively recycled; In addition, although the traditional solar photovoltaic photo-thermal (PVT) system can synchronously acquire electric energy and heat energy, the output temperature of a hot end is generally low, the high-grade heat source requirement required by PEM electrolysis is difficult to meet, and the dynamic temperature adjusting capability and the voltage matching capability which are suitable for the running characteristics of an electrolytic cell are lacked. Currently, the relevant prior art is: the prior Chinese patent application document with the publication number of CN114672834A discloses a combined heat and power system and a method based on a photovoltaic hydrogen production coupling fuel cell, which are provided with a photovoltaic power generation module, wherein a first output end of the photovoltaic power generation module is connected with an input end of an inverter module to provide a direct current power supply for the inverter module, an output end of the inverter module is used for providing an alternating current power supply for a household appliance, a second output end of the photovoltaic power generation module is connected with a power end of an electrolytic hydrogen production module to provide power for electrolytic hydrogen production, an oxygen output end of the electrolytic hydrogen production module is connected with an oxygen storage module, a hydrogen output end is connected with a hydrogen storage module, output ends of the oxygen storage module and the hydrogen storage module are respectively connected with an oxygen inlet and a hydrogen inlet of the fuel cell module, an output end of the fuel cell module is connected with an input end of the inverter module, heat exchange modules are respectively arranged in the photovoltaic power generation module, the electrolytic hydrogen production module and the fuel cell module, and an output end of each heat exchange module is respectively connected with a thermoelectric combination module, a