Wind power-photovoltaic-photo-thermal cold power co-production system integrating heat pump energy storage and suitable for large energy base

Abstract

The invention discloses a wind power-photovoltaic-photo-thermal cold power co-production system integrating heat pump energy storage and suitable for a large energy base, and belongs to the technical field of energy storage. A hot side outlet of a steam generator of the system is connected with an inlet of a second molten salt tank through a fourth molten salt pump, an outlet of the second molten salt tank is connected with an inlet of a first three-way valve through a second molten salt pump, and a first outlet of the first three-way valve is connected with an inlet of a heat collection tower. An outlet of the heat collecting tower is connected with a first inlet of a second three-way valve through a first molten salt pump; an outlet of the second three-way valve is connected with an inlet of a first molten salt tank; the compressor is connected with a hot-side inlet of the first heat exchanger, a hot-side outlet of the first heat exchanger is connected with an inlet of the turbine through a hot side of the second heat exchanger, and an outlet of the turbine is connected with an inlet of the compressor sequentially through a hot side of the third heat exchanger and a cold side of the second heat exchanger. According to the system, cold energy can be supplied to the outside through the heat pump energy storage system in the energy storage stage, cold and power cogeneration is achieved, and the comprehensive energy efficiency of the large energy base is improved.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a wind power-photovoltaic-solar-thermal-cooling-power cogeneration system with integrated heat pump energy storage suitable for large energy bases. Background Art

[0002] my country's wind and solar energy are widely distributed and have huge reserves, especially in deserts, Gobi and wasteland areas. Under the "dual carbon" goal, new energy represented by wind and solar energy will develop on a larger scale and at a faster pace. The construction of large wind and photovoltaic energy bases is the top priority for my country to develop new energy and accelerate the construction of a new energy system. The randomness, periodicity and anti-peak characteristics of wind and solar energy affect the grid connection and consumption of wind and photovoltaic power generation. The contradiction between the substantial growth of my country's new energy installed capacity and its efficient consumption has led to the phenomenon of "abandoning wind and light" in some areas.

[0003] Energy storage technology, as a representative of flexible regulation technology, has the advantages of rapid response and flexible energy throughput, and plays an important role in coping with fluctuations in wind power and photovoltaic power. Heat pump energy storage technology, also known as Carnot battery, is a new type of electric energy storage technology based on power cycle and cold and heat storage technology. It has the advantages of not being restricted by terrain conditions, high energy storage density, low investment cost and long energy storage cycle. Designing a wind power-photovoltaic-solar heat and cold power cogeneration system with integrated heat pump energy storage suitable for large energy bases can effectively solve the problem of "abandoning wind and light". Summary of the invention

[0004] The purpose of the present invention is to propose a wind power-photovoltaic-photothermal cooling and power cogeneration system with integrated heat pump energy storage suitable for large energy bases, including a photothermal power generation system, a wind power photovoltaic power generation system and a heat pump energy storage system; the photothermal power generation system includes a heliostat field, a collector tower, a first molten salt pump, a first three-way valve, a second three-way valve, a second molten salt pump, a first molten salt tank, a second molten salt tank, a third molten salt pump, a fourth molten salt pump, a steam generator, a steam turbine, a generator, a condenser, a condensate pump, a regenerative heater and a feed water pump;

[0005] The hot side outlet of the steam generator is connected to the inlet of the second molten salt tank via the fourth molten salt pump, the outlet of the second molten salt tank is connected to the inlet of the first three-way valve via the second molten salt pump, the first outlet of the first three-way valve is connected to the inlet of the heat collecting tower, the outlet of the heat collecting tower is connected to the first inlet of the second three-way valve via the first molten salt pump, the outlet of the second three-way valve is connected to the inlet of the first molten salt tank, and the outlet of the first molten salt tank is connected to the hot side inlet of the steam generator via the third molten salt pump;

[0006] The heat pump energy storage system includes a motor, a compressor, a first heat exchanger, a second heat exchanger, a turbine and a third heat exchanger;

[0007] Among them, the wind power photovoltaic power generation system, the motor, the compressor, and the turbine are connected in sequence, the compressor is connected to the hot side inlet of the first heat exchanger, the hot side outlet of the first heat exchanger is connected to the inlet of the turbine via the hot side of the second heat exchanger, the outlet of the turbine is connected to the inlet of the compressor via the hot side of the third heat exchanger and the cold side of the second heat exchanger in sequence, the second outlet of the first three-way valve is connected to the cold side inlet of the first heat exchanger, and the second inlet of the second three-way valve is connected to the cold side outlet of the first heat exchanger.

[0008] Furthermore, the cold side outlet of the steam generator is connected to the inlet of the steam turbine, the steam extraction port of the steam turbine is connected to the hot side inlet of the regenerative heater, the steam exhaust port of the steam turbine is connected to the cold side inlet of the regenerative heater via the condenser and the condensate pump in sequence, the cold side outlet of the regenerative heater is connected to the cold side inlet of the steam generator via the feed water pump, and the steam turbine is connected to the generator.

[0009] Furthermore, the wind power photovoltaic power generation system includes photovoltaic cells and a wind turbine.

[0010] A working method of a wind power-photovoltaic-solar-thermal-cold-power cogeneration system with integrated heat pump energy storage suitable for a large energy base, including an energy storage process and an energy release process; wherein the energy storage process is specifically:

[0011] The abandoned wind and solar power that cannot be absorbed by the wind power and photovoltaic power generation system drives the motor to drive the compressor to work. The abandoned wind and solar power is converted into thermal energy of high-pressure air. The thermal energy enters the first heat exchanger and transfers the heat to the low-temperature molten salt at the outlet of the second molten salt tank. The molten salt after absorbing heat enters the first molten salt tank for storage from the cold side outlet of the first heat exchanger through the second inlet of the second three-way valve. The high-pressure air at the hot side outlet of the first heat exchanger passes through the second heat exchanger to transfer the waste heat to the low-pressure air at the inlet of the compressor. The gas at the hot side outlet of the second heat exchanger enters the turbine to expand and do work, and the generated cold energy is transferred to the cold user through the third heat exchanger. In the solar thermal power generation system, the low-temperature molten salt at the outlet of the second molten salt tank enters the thermal collector tower to absorb the heat gathered by the heliostat field. The molten salt after absorbing heat enters the first molten salt tank for storage from the outlet of the thermal collector tower through the first molten salt pump and the second three-way valve.

[0012] The specific energy release process is as follows:

[0013] The exhaust steam from the steam turbine enters the condenser and is cooled into liquid water. The liquid water at the outlet of the condensate pump absorbs the heat of the steam extracted from the steam turbine through the regenerative heater. The liquid water at the outlet of the cold side of the regenerative heater is pressurized by the feed water pump and enters the steam generator, absorbing the heat of the high-temperature molten salt at the outlet of the first molten salt tank. The high-temperature and high-pressure steam after absorbing heat enters the steam turbine through the outlet of the cold side of the steam generator to perform work, thereby driving the generator to generate electricity.

[0014] The beneficial effects of the present invention are:

[0015] 1. The heat pump energy storage system can absorb the surplus power of wind power and photovoltaic power, improve the flexible adjustment ability of the power supply side of the power system such as large wind and solar energy bases, and thus improve the development and absorption level of new energy, and alleviate the contradiction between the rapid development of new energy and efficient absorption;

[0016] 2. The heat pump energy storage system and the CSP system share the energy storage unit, including the molten salt energy storage medium, the first molten salt tank and the second molten salt tank, which can realize the conversion of electrical energy into thermal energy, reduce the dependence of the CSP power station on the mirror field, and significantly reduce the area investment of the mirror field;

[0017] 3. The heat pump energy storage system and the solar thermal power generation system share the power generation process, which reduces the investment cost of the complementary system while ensuring the continuous and flexible operation of solar thermal power generation;

[0018] 4. The cogeneration system can realize the energy release process. The steam-Rankine power generation cycle of the solar thermal power station and the wind power and photovoltaic power generation system can jointly produce electricity, coordinate the complementary effects between different energy sources, and can also supply cold energy to the outside through the heat pump energy storage system during the energy storage stage, realize the cogeneration of cold and electricity, and improve the comprehensive energy efficiency of large energy bases. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of a wind power-photovoltaic-solar-thermal-cooling-power cogeneration system with integrated heat pump energy storage suitable for large energy bases according to the present invention. DETAILED DESCRIPTION

[0020] The present invention proposes a wind power-photovoltaic-solar-thermal-cooling-power cogeneration system with integrated heat pump energy storage suitable for large energy bases. The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0021] Figure 1 The present invention is a schematic structural diagram of a wind power-photovoltaic-solar thermal cooling and power cogeneration system with integrated heat pump energy storage suitable for a large energy base, the system comprising a solar thermal power generation system 1, a wind power photovoltaic power generation system 2 and a heat pump energy storage system 3;

[0022] The solar thermal power generation system 1 includes a heliostat field 4, a collector tower 5, a first molten salt pump 14, a first three-way valve 15, a second three-way valve 16, a second molten salt pump 17, a first molten salt tank 18, a second molten salt tank 19, a third molten salt pump 20, a fourth molten salt pump 21, and a steam-Rankine power generation cycle; the steam-Rankine power generation cycle includes a steam generator 22, a steam turbine 23, a generator 24, a condenser 25, a condensate pump 26, a regenerative heater 27, and a feed water pump 28;

[0023] The hot side outlet of the steam generator 22 is connected to the inlet of the second molten salt tank 19 via the fourth molten salt pump 21, the outlet of the second molten salt tank 19 is connected to the inlet of the first three-way valve 15 via the second molten salt pump 17, the first outlet of the first three-way valve 15 is connected to the inlet of the heat collecting tower 5, the outlet of the heat collecting tower 5 is connected to the first inlet of the second three-way valve 16 via the first molten salt pump 14, the outlet of the second three-way valve 16 is connected to the inlet of the first molten salt tank 18, and the outlet of the first molten salt tank 18 is connected to the hot side inlet of the steam generator 22 via the third molten salt pump 20;

[0024] The heat pump energy storage system 3 includes a motor 8, a compressor 9, a first heat exchanger 10, a second heat exchanger 11, a turbine 12 and a third heat exchanger 13;

[0025] Among them, the wind power photovoltaic power generation system 2, the motor 8, the compressor 9, and the turbine 12 are connected in sequence, the compressor 9 is connected to the hot side inlet of the first heat exchanger 10, the hot side outlet of the first heat exchanger 10 is connected to the inlet of the turbine 12 via the hot side of the second heat exchanger 11, the outlet of the turbine 12 is connected to the inlet of the compressor 9 via the hot side of the third heat exchanger 13 and the cold side of the second heat exchanger 11 in sequence, the second outlet of the first three-way valve 15 is connected to the cold side inlet of the first heat exchanger 10, and the second inlet of the second three-way valve 16 is connected to the cold side outlet of the first heat exchanger 10.

[0026] The cold side outlet of the steam generator 22 is connected to the inlet of the steam turbine 23, the steam extraction port of the steam turbine 23 is connected to the hot side inlet of the regenerative heater 27, the steam exhaust port of the steam turbine 23 is connected to the cold side inlet of the regenerative heater 27 via the condenser 25 and the condensate pump 26 in sequence, the cold side outlet of the regenerative heater 27 is connected to the cold side inlet of the steam generator 22 via the feed water pump 28, and the steam turbine 23 is connected to the generator 24.

[0027] The wind power photovoltaic power generation system 2 includes a photovoltaic cell 6 and a wind turbine 7 .

[0028] An embodiment of the present invention provides a working method of a wind power-photovoltaic-solar thermal cooling and power cogeneration system with integrated heat pump energy storage suitable for a large energy base, including an energy storage process and an energy release process:

[0029] During the energy storage process, the surplus electricity of the wind power photovoltaic power generation system 2 enters the motor 8 to drive the compressor 9, and the compressor 9 converts the electrical energy into the heat energy of the high-pressure air. The high-temperature and high-pressure air enters the first heat exchanger 10, and transfers the heat to the low-temperature molten salt at the outlet of the second molten salt tank 19. The molten salt after absorbing heat enters the first molten salt tank 18 for storage from the cold side outlet of the first heat exchanger 10 through the second inlet of the second three-way valve 16. The high-pressure air at the hot side outlet of the first heat exchanger 10 enters the second heat exchanger 11, and transfers the waste heat to the low-pressure air at the inlet of the compressor 9. The gas at the hot side outlet of the second heat exchanger 11 enters the turbine 12 to expand and do work, thereby producing The generated cold energy is transferred to the cold user through the third heat exchanger 13 to realize the function of external cold supply. The low-pressure and low-temperature air at the hot side outlet of the third heat exchanger 13 enters the cold side of the second heat exchanger 11 to absorb heat, and the gas after absorbing heat enters the compressor 9 to restart the next cycle. In the solar thermal power generation system 1, the heliostat field 4 focuses sunlight on the collector tower 5 to heat the molten salt. The low-temperature molten salt in the second molten salt tank 19 is transported by the second molten salt pump 17, and enters the collector tower 5 after passing through the first three-way valve 15 to absorb light and heat. The high-temperature molten salt after absorbing heat is transported by the first molten salt pump 14, and enters the first molten salt tank 18 for storage through the second three-way valve 16.

[0030] During the energy release process, the exhaust steam of the steam turbine 23 enters the condenser 25 and is cooled into liquid water. The liquid water at the outlet of the condensate pump 26 absorbs the heat of the steam extraction of the steam turbine through the regenerative heater 27. The liquid water at the cold side outlet of the regenerative heater 27 is pressurized by the feed water pump 28 and enters the steam generator 22. The high-temperature molten salt of the first molten salt tank 18 is transported to the steam generator 22 through the third molten salt pump 20. The liquid water entering the cold side of the steam generator 22 absorbs the heat of the high-temperature molten salt at the outlet of the first molten salt tank 18. The high-temperature and high-pressure steam after absorbing heat enters the steam turbine 23 through the cold side outlet of the steam generator 22 to perform work, thereby driving the generator 24 to generate electricity. The wind power photovoltaic power generation system 2 and the solar thermal power generation system 1 can realize two modes of parallel power generation and series power generation. In the parallel mode, the wind power photovoltaic power generation system and the solar thermal power generation system can operate simultaneously to generate electricity together. In the series mode, the wind power photovoltaic power generation system 2 and the solar thermal power generation system 1 can flexibly adjust the power generation sequence and make reasonable configuration to achieve effective energy utilization.

[0031] The wind power-photovoltaic-solar thermal cooling and power cogeneration system with integrated heat pump energy storage provided by the present invention, which is suitable for large energy bases, can solve the contradiction between the rapid development of new energy installed capacity and efficient consumption, reduce the investment in large energy bases, and improve the operation flexibility of large energy bases. Specifically, the heat pump energy storage system of the present invention can absorb the surplus wind power and photovoltaic power generation system of the wind power and photovoltaic power generation system, reduce the occurrence of wind and photovoltaic abandonment, and improve the new energy consumption level of large energy bases; in the solar thermal power generation system, the mirror field and the collector tower are used to realize the conversion of solar energy into thermal energy, and the heat pump energy storage system can realize the conversion of electrical energy into thermal energy, thereby reducing the dependence of the solar thermal power generation system on the mirror field and reducing the mirror field area; the heat pump energy storage system can share the thermal power generation part with the solar thermal power generation system, reducing the investment cost of the complementary system; the heat pump energy storage system can realize the output of cold energy during the energy storage process, thereby realizing the cogeneration of cold and power of the wind power-photovoltaic-solar thermal system with integrated heat pump energy storage, and improving the comprehensive energy efficiency of the large energy base. In addition, the working method of the embodiment of the present invention uses the abandoned electricity of wind power and photovoltaic power as energy input, uses air as the circulating working fluid of the heat pump energy storage system, uses water as the circulating working fluid of the solar thermal power generation system, and uses molten salt as the heat storage medium of the heat storage unit. The system takes into account the characteristics of the heat pump energy storage system and the cogeneration system, and has the advantages of flexible operation and high energy storage density. It can further improve the consumption level of new energy such as wind energy and solar energy, help to improve the development level of new energy installed capacity, and promote the transformation of my country's energy structure.

Claims

1. A wind power-photovoltaic-solar-thermal-cold-power cogeneration system with integrated heat pump energy storage suitable for large energy bases, characterized in that: It comprises a solar thermal power generation system (1), a wind power photovoltaic power generation system (2) and a heat pump energy storage system (3); The solar thermal power generation system (1) comprises a heliostat field (4), a heat collecting tower (5), a first molten salt pump (14), a first three-way valve (15), a second three-way valve (16), a second molten salt pump (17), a first molten salt tank (18), a second molten salt tank (19), a third molten salt pump (20), a fourth molten salt pump (21), a steam generator (22), a steam turbine (23), a generator (24), a condenser (25), a condensate pump (26), a regenerative heater (27) and a feed water pump (28); The hot side outlet of the steam generator (22) is connected to the inlet of the second molten salt tank (19) via a fourth molten salt pump (21), the outlet of the second molten salt tank (19) is connected to the inlet of the first three-way valve (15) via a second molten salt pump (17), the first outlet of the first three-way valve (15) is connected to the inlet of the heat collecting tower (5), the outlet of the heat collecting tower (5) is connected to the first inlet of the second three-way valve (16) via a first molten salt pump (14), the outlet of the second three-way valve (16) is connected to the inlet of the first molten salt tank (18), and the outlet of the first molten salt tank (18) is connected to the hot side inlet of the steam generator (22) via a third molten salt pump (20); The heat pump energy storage system (3) comprises an electric motor (8), a compressor (9), a first heat exchanger (10), a second heat exchanger (11), a turbine (12) and a third heat exchanger (13); The wind power photovoltaic power generation system (2), the motor (8), the compressor (9), and the turbine (12) are connected in sequence; the compressor (9) is connected to the hot side inlet of the first heat exchanger (10); the hot side outlet of the first heat exchanger (10) is connected to the inlet of the turbine (12) via the hot side of the second heat exchanger (11); the outlet of the turbine (12) is connected to the inlet of the compressor (9) via the hot side of the third heat exchanger (13) and the cold side of the second heat exchanger (11) in sequence; the second outlet of the first three-way valve (15) is connected to the cold side inlet of the first heat exchanger (10); and the second inlet of the second three-way valve (16) is connected to the cold side outlet of the first heat exchanger (10).

2. The wind power-photovoltaic-solar-thermal-cooling-power cogeneration system with integrated heat pump energy storage suitable for large energy bases according to claim 1, characterized in that: The cold side outlet of the steam generator (22) is connected to the inlet of the steam turbine (23), the steam extraction port of the steam turbine (23) is connected to the hot side inlet of the regenerative heater (27), the steam exhaust port of the steam turbine (23) is connected to the cold side inlet of the regenerative heater (27) via the condenser (25) and the condensate pump (26) in sequence, the cold side outlet of the regenerative heater (27) is connected to the cold side inlet of the steam generator (22) via the feed water pump (28), and the steam turbine (23) is connected to the generator (24).

3. The wind power-photovoltaic-solar-thermal-cold-power cogeneration system with integrated heat pump energy storage suitable for large energy bases according to claim 2, characterized in that: The wind power photovoltaic power generation system (2) comprises a photovoltaic cell (6) and a wind power generator (7).

4. A working method of a wind power-photovoltaic-solar-thermal-cooling-power cogeneration system with integrated heat pump energy storage suitable for a large energy base as described in claim 3, characterized in that: It includes energy storage process and energy release process; the energy storage process is specifically as follows: The abandoned wind and solar power that cannot be absorbed by the wind power and photovoltaic power generation system (2) drives the motor (8) to drive the compressor (9) to work, and the abandoned wind and solar power is converted into heat energy of high-pressure air. The heat energy enters the first heat exchanger (10) and transfers the heat to the low-temperature molten salt at the outlet of the second molten salt tank (19). The molten salt after absorbing heat enters the first molten salt tank (18) for storage from the cold side outlet of the first heat exchanger (10) through the second inlet of the second three-way valve (16). The high-pressure air at the hot side outlet of the first heat exchanger (10) passes through the second heat exchanger (11). The waste heat is transferred to the low-pressure air at the inlet of the compressor (9), and the gas at the hot side outlet of the second heat exchanger (11) enters the turbine (12) to expand and do work, and the generated cold energy is transferred to the cold user through the third heat exchanger (13); in the solar thermal power generation system (1), the low-temperature molten salt at the outlet of the second molten salt tank (19) enters the heat collecting tower (5) to absorb the heat gathered by the heliostat field (4), and the molten salt after absorbing heat enters the first molten salt tank (18) for storage from the outlet of the heat collecting tower (5) through the first molten salt pump (14) and the second three-way valve (16).

5. The working method of the wind power-photovoltaic-solar-thermal-cold-power cogeneration system with integrated heat pump energy storage suitable for large energy bases according to claim 4, characterized in that: The energy release process is specifically as follows: The exhaust steam of the steam turbine (23) enters the condenser (25) and is cooled into liquid water. The liquid water at the outlet of the condensate pump (26) absorbs the heat of the steam extracted by the steam turbine (23) through the regenerative heater (27). The liquid water at the cold side outlet of the regenerative heater (27) is pressurized by the feed water pump (28) and enters the steam generator (22), absorbing the heat of the high-temperature molten salt at the outlet of the first molten salt tank (18). The high-temperature and high-pressure steam after absorbing heat enters the steam turbine (23) through the cold side outlet of the steam generator (22) to perform work, thereby driving the generator (24) to generate electricity.

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