An energy storage power generation and heating system coupling solar energy and geothermal energy

Abstract

The application discloses an energy storage power generation and heating system coupled with solar energy and geothermal energy, wherein the outlet of a compressor is communicated with the heat release side inlet of a high-pressure cooler, the outlet of the heat release side of the high-pressure cooler is communicated with the inlet of a high-temperature layer pipeline in a geothermal field, the outlet of the high-temperature layer pipeline in the geothermal field is communicated with the heat absorption side inlet of a carbon dioxide-molten salt heat exchanger, the heat absorption side outlet of the carbon dioxide-molten salt heat exchanger is communicated with the inlet of an expander, the outlet of the expander is communicated with the heat release side inlet of a low-pressure cooler, and the heat release side outlet of the low-pressure cooler is communicated with the inlet of the compressor; the heating system is connected with the heat absorption side of the high-pressure cooler, the heat absorption side of the low-pressure cooler and the medium-temperature layer pipeline in the geothermal field, and the solar light and heat system is communicated with the heat release side of the carbon dioxide-molten salt heat exchanger; the system has high power generation efficiency, and the gas-liquid two-phase flow in the heat exchanger is stable.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of energy storage, and relates to an energy storage power generation and heating system coupled with solar energy and geothermal energy. BACKGROUND

[0002] In order to solve the problem of power fluctuation after intermittent new energy is integrated into the power grid, it is an inevitable trend to enrich energy storage technology and develop efficient power generation technology. The compressed gas energy storage technology has the characteristics of large scale, good safety, long service life and environmental friendliness. The gas working medium can be air, carbon dioxide, etc. Compared with air, carbon dioxide has the advantages of stable properties, low price, wide sources and liquefaction at room temperature, and has obvious advantages in carbon reduction and working medium storage. The Carnot battery using carbon dioxide as the working medium can store energy by compressing the working medium and generate power by expanding the working medium, and can realize the mutual conversion between mechanical energy and thermal energy, gradually becoming one of the most potential emerging energy storage and power generation technologies.

[0003] Patent CN 113659728 A provides a Carnot battery for realizing large-scale storage of electric power. However, the highest temperature at the inlet of the expander during power generation is the temperature at the outlet of the compressor during the cold storage process, and the system cannot achieve high power generation efficiency. Patent CN 114033518 A uses solar energy to combine with the Carnot battery for cold-heat-electricity-water combined supply. However, the system directly uses a heat exchanger to convert saturated liquid into high-temperature and high-pressure gas during power generation, and the gas-liquid two-phase flow in the heat exchanger is unstable and easy to cause equipment damage. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide an energy storage power generation and heating system coupled with solar energy and geothermal energy. The power generation efficiency of the system is high, and the gas-liquid two-phase flow in the heat exchanger is stable.

[0005] To achieve the above-mentioned purpose, the energy storage power generation and heating system coupled with solar energy and geothermal energy comprises a solar photo-thermal system, a heating system and a Carnot battery cold storage and power generation system, wherein the Carnot battery cold storage and power generation system comprises a compressor, a high-pressure cooler, a geothermal field, a carbon dioxide-salt heat exchanger, an expander and a low-pressure cooler.

[0006] The outlet of the compressor is in communication with the inlet of the heat-releasing side of the high-pressure cooler, the outlet of the heat-releasing side of the high-pressure cooler is in communication with the inlet of the high-temperature layer pipeline in the geothermal field, the outlet of the high-temperature layer pipeline in the geothermal field is in communication with the inlet of the heat-absorbing side of the carbon dioxide-salt heat exchanger, the outlet of the heat-absorbing side of the carbon dioxide-salt heat exchanger is in communication with the inlet of the expander, the outlet of the expander is in communication with the inlet of the heat-releasing side of the low-pressure cooler, and the outlet of the heat-releasing side of the low-pressure cooler is in communication with the inlet of the compressor.

[0007] The heat supply system is connected with the pipe side of the high-pressure cooler, the heat releasing side of the low-pressure cooler and the pipe of the middle temperature layer in the geothermal field.

[0008] The outlet of the heat releasing side of the low-pressure cooler is connected with the inlet of the compressor through a flexible air chamber.

[0009] The outlet of the heat releasing side of the high-pressure cooler is connected with the inlet of the pipe of the high temperature layer in the geothermal field through a liquid storage tank.

[0010] The compressor is connected with a motor, and the expander is connected with a generator.

[0011] The heat supply system comprises a low temperature user end and a cooling pump.

[0012] The outlet of the low temperature user end is divided into two paths after the cooling pump, one of which is connected with the inlet of the low temperature user end through the heat absorbing side of the high-pressure cooler, and the other of which is connected with the inlet of the low temperature user end through the heat absorbing side of the low-pressure cooler.

[0013] The heat supply system comprises a high temperature user end, a circulating pump and a heat exchanger.

[0014] The outlet of the pipe of the middle temperature layer in the geothermal field is connected with the inlet of the pipe of the middle temperature layer in the geothermal field through the heat absorbing side of the heat exchanger, the high temperature user end and the circulating pump in sequence.

[0015] The solar light heat system comprises a solar heat collector, a high temperature molten salt tank and a low temperature molten salt tank.

[0016] The outlet of the high temperature molten salt tank is divided into two paths, one of which is connected with the inlet of the low temperature molten salt tank through the heat releasing side of the heat exchanger, and the other of which is connected with the inlet of the low temperature molten salt tank through the heat releasing side of the carbon dioxide-molten salt heat exchanger, the outlet of the low temperature molten salt tank is connected with the inlet of the solar heat collector, and the outlet of the solar heat collector is connected with the inlet of the high temperature molten salt tank.

[0017] The outlet of the low temperature molten salt tank is connected with the inlet of the solar heat collector through a molten salt pump.

[0018] The application further comprises a heliostat, and the sunlight is reflected to the solar heat collector through the heliostat.

[0019] The application has the following beneficial effects:

[0020] The energy storage power generation and heating system coupling solar energy and geothermal energy disclosed in the application, in specific operation, realizes the conversion of liquid carbon dioxide to gaseous carbon dioxide by arranging the high-temperature layer channel in the geothermal field in front of the carbon dioxide-molten salt heat exchanger, avoids the heat exchanger damage caused by unstable gas-liquid two-phase flow, and the gas-liquid two-phase flow in the heat exchanger is relatively stable. In addition, the high-temperature layer channel in the geothermal field and the carbon dioxide-molten salt heat exchanger are arranged in front of the expander inlet, and through the cascade utilization of solar energy and geothermal energy in the Carnot cell power generation system, efficient power generation is realized, and the power generation efficiency is relatively high. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The system structure diagram of the application is shown.

[0022] Among them, 1-1 is a flexible air chamber, 1-2 is a compressor, 1-3 is a high-pressure cooler, 1-4 is a liquid storage tank, 1-5 is a geothermal field, 1-6 is a carbon dioxide-molten salt heat exchanger, 1-7 is an expander, 1-8 is a low-pressure cooler, 1-9 is a motor, 1-10 is a generator, 2-1 is a heliostat, 2-2 is a solar collector, 2-3 is a high-temperature molten salt tank, 2-4 is a low-temperature molten salt tank, 2-5 is a molten salt pump, 3-1 is a high-temperature user end, 3-2 is a circulating pump, 3-3 is a heat exchanger, 3-4 is a low-temperature user end, and 3-5 is a cooling pump. DETAILED DESCRIPTION

[0023] In order for those skilled in the art to better understand the application, the technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, not all the embodiments, and are not intended to limit the scope of the application disclosed. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concepts disclosed in the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the application.

[0024] The structural schematic diagram according to the disclosed embodiments of the application is shown in the drawings. These drawings are not drawn to scale, in which some details are exaggerated for the purpose of clear expression, and some details may be omitted. The shapes of various regions, layers and their relative size and positional relationship shown in the drawings are only exemplary, and in actuality, there may be deviations due to manufacturing tolerances or technical limitations, and the regions / layers with different shapes, sizes and relative positions can be additionally designed by those skilled in the art according to actual needs.

[0025] REFERENCE Figure 1The energy storage power generation and heating system coupling solar energy and geothermal energy comprises a Carnot cell cold storage power generation system, a solar light and heat system and a heating system; the solar light and heat system is connected with the Carnot cell cold storage power generation system and the heating system, and the Carnot cell cold storage power generation system is connected with the heating system.

[0026] The solar light and heat system comprises a heliostat 2-1, a solar heat collector 2-2, a high-temperature molten salt tank 2-3, a low-temperature molten salt tank 2-4 and a molten salt pump 2-5; the heating system comprises a high-temperature user end 3-1, a circulating pump 3-2, a heat exchanger 3-3, a low-temperature user end 3-4 and a cooling pump 3-5; and the Carnot cell cold storage power generation system comprises a flexible air chamber 1-1, a compressor 1-2, a high-pressure cooler 1-3, a liquid storage tank 1-4, a geothermal field 1-5, a carbon dioxide-molten salt heat exchanger 1-6, an expander 1-7, a low-pressure cooler 1-8, a motor 1-9 and a generator 1-10.

[0027] The outlet of the compressor 1-2 is communicated with the heat-releasing side inlet of the high-pressure cooler 1-3, the heat-releasing side outlet of the high-pressure cooler 1-3 is communicated with the inlet of the liquid storage tank 1-4, the outlet of the liquid storage tank 1-4 is communicated with the inlet of the high-temperature layer pipeline in the geothermal field 1-5, the outlet of the high-temperature layer pipeline in the geothermal field 1-5 is communicated with the heat-absorbing side inlet of the carbon dioxide-molten salt heat exchanger 1-6, the heat-absorbing side outlet of the carbon dioxide-molten salt heat exchanger 1-6 is communicated with the inlet of the expander 1-7, the outlet of the expander 1-7 is communicated with the heat-releasing side inlet of the low-pressure cooler 1-8, the heat-releasing side outlet of the low-pressure cooler 1-8 is communicated with the inlet of the flexible air chamber 1-1, and the outlet of the flexible air chamber 1-1 is communicated with the inlet of the compressor 1-2; the compressor 1-2 is connected with the motor 1-9, and the expander 1-7 is connected with the generator 1-10.

[0028] The outlet of the low-temperature user end 3-4 is divided into two paths after passing through the cooling pump 3-5, one of the two paths is communicated with the inlet of the low-temperature user end 3-4 through the heat-absorbing side of the high-pressure cooler 1-3, and the other path is communicated with the inlet of the low-temperature user end 3-4 through the heat-absorbing side of the low-pressure cooler 1-8.

[0029] The outlet of the middle-temperature layer pipeline in the geothermal field 1-5 is communicated with the inlet of the middle-temperature layer pipeline in the geothermal field 1-5 in sequence through the heat-absorbing side of the heat exchanger 3-3, the high-temperature user end 3-1 and the circulating pump 3-2.

[0030] The outlet of the high-temperature molten salt tank 2-3 is divided into two paths, one of the two paths is communicated with the inlet of the low-temperature molten salt tank 2-4 through the heat-releasing side of the heat exchanger 3-3, the other path is communicated with the inlet of the low-temperature molten salt tank 2-4 through the heat-releasing side of the carbon dioxide-molten salt heat exchanger 1-6, the outlet of the low-temperature molten salt tank 2-4 is communicated with the inlet of the solar heat collector 2-2 through the molten salt pump 2-5, and the outlet of the solar heat collector 2-2 is communicated with the inlet of the high-temperature molten salt tank 2-3.

[0031] The working medium in the heat supply system is water, heat-conducting oil or refrigerant; the working medium in the Carnot cell cold storage power generation system can be replaced by other organic working medium; the motor 1-9 in the Carnot cell cold storage process is powered by renewable energy, such as wind power and photovoltaic power.

[0032] The specific working process of the application is as follows:

[0033] During the Carnot cell cold storage, the motor 1-9 drives the compressor 1-2 to operate, compresses and heats the low-temperature and low-pressure carbon dioxide from the flexible air tank 1-1, and the high-temperature and high-pressure carbon dioxide formed after being heated and pressurized enters the heat release side of the high-pressure cooler 1-3 to release heat to the low-temperature heat supply system, and the low-temperature and high-pressure carbon dioxide formed after heat release enters the liquid storage tank 1-4 for cold storage. During the Carnot cell cold storage process, the low-temperature heat supply system is coupled, and the heat energy of the carbon dioxide on the heat release side of the high-pressure cooler 1-3 is converted into the heat energy of the working medium on the heat absorption side of the high-pressure cooler 1-3.

[0034] During the Carnot cell power generation, the low-temperature and high-pressure carbon dioxide in the liquid storage tank 1-4 enters the high-temperature layer channel in the geothermal field 1-5 and the heat absorption side of the carbon dioxide-molten salt heat exchanger 1-6 to be heated, and then enters the expander 1-7 to be expanded and released to form medium-temperature and low-pressure carbon dioxide, while the expander 1-7 drives the generator 1-10 to rotate to generate electricity, and then the medium-temperature and low-pressure carbon dioxide enters the heat release side of the low-pressure cooler 1-8 to release heat and form low-temperature and low-pressure carbon dioxide, and finally enters the flexible air tank 1-1 for storage. During the Carnot cell power generation process, the solar thermal system is coupled, and the heat energy of the molten salt on the heat release side of the carbon dioxide-molten salt heat exchanger 1-6 is converted into the heat energy of the carbon dioxide on the heat absorption side of the carbon dioxide-molten salt heat exchanger 1-6.

[0035] During the heat storage of the solar thermal system, the low-temperature molten salt in the low-temperature molten salt tank 2-4 is pumped to the solar collector 2-2 by the molten salt pump 2-5, the heliostat 2-1 focuses sunlight on the solar collector 2-2 to convert light energy into heat energy to heat the low-temperature molten salt to high-temperature molten salt, and then the high-temperature molten salt enters the high-temperature molten salt tank 2-3 for heat storage.

[0036] During the heat release of the solar thermal system, part of the high-temperature molten salt in the high-temperature molten salt tank 2-3 enters the heat release side of the carbon dioxide-molten salt heat exchanger 1-6 to release heat to the heat absorption side of the carbon dioxide-molten salt heat exchanger 1-6 to become low-temperature molten salt, and the other part of the high-temperature molten salt enters the heat release side of the heat exchanger 3-3 to release heat to the heat absorption side of the heat exchanger 3-3 to become low-temperature molten salt, and then the two are combined and stored in the low-temperature molten salt tank 2-4.

[0037] When the high-temperature heat supply system supplies heat, the low-temperature working medium on the heat releasing side of the high-temperature user end 3-1 is pressurized by the circulating pump 3-2, and then sequentially absorbs heat on the heat absorbing side of the geothermal field 1-5 and the heat absorbing side of the heat exchanger 3-3, and finally releases heat on the heat releasing side of the high-temperature user end 3-1. The high-temperature heat supply system is coupled with the solar light and heat system, and the heat energy of the molten salt on the heat releasing side of the heat exchanger 3-3 is converted into the heat energy of the working medium on the heat absorbing side of the heat exchanger 3-3.

[0038] When the low-temperature heat supply system supplies heat, the low-temperature working medium on the heat absorbing side of the low-temperature user end 3-4 is pressurized by the cooling pump 3-5, and part of it absorbs heat on the heat absorbing side of the high-pressure cooler 1-3 to become high-temperature working medium, and the other part absorbs heat on the heat absorbing side of the low-pressure cooler 1-8 to become high-temperature working medium, and then the two are combined and released on the heat releasing side of the low-temperature user end 3-4.

[0039] The present application realizes the transformation of carbon dioxide from liquid to gas by arranging the geothermal field 1-5 in front of the carbon dioxide-molten salt heat exchanger 1-6, avoiding the problem of heat exchanger 3-3 damage caused by unstable gas-liquid two-phase flow. In addition, the present application arranges the geothermal field 1-5 and the carbon dioxide-molten salt heat exchanger 1-6 in front of the inlet of the expander 1-7, and realizes efficient power generation by using solar energy and geothermal energy in a cascade manner in the Carnot cell power generation system.

[0040] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application and not to limit it, although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that: the specific embodiments of the present application can still be modified or replaced by equivalents without departing from the spirit and scope of the present application, any modification or equivalent replacement thereof should be covered within the protection scope of the claims of the present application.

Claims

1. An energy storage, power generation, and heating system coupling solar and geothermal energy, characterized in that, It includes a solar thermal system, a heating system and a Carnot battery cold storage power generation system. The Carnot battery cold storage power generation system includes a compressor (1-2), a high-pressure cooler (1-3), a geothermal field (1-5), a carbon dioxide-molten salt heat exchanger (1-6), an expander (1-7) and a low-pressure cooler (1-8). The outlet of the compressor (1-2) is connected to the heat release side inlet of the high-pressure cooler (1-3), the heat release side outlet of the high-pressure cooler (1-3) is connected to the inlet of the high-temperature layer pipe in the geothermal field (1-5), the outlet of the high-temperature layer pipe in the geothermal field (1-5) is connected to the heat absorption side inlet of the carbon dioxide-molten salt heat exchanger (1-6), the heat absorption side outlet of the carbon dioxide-molten salt heat exchanger (1-6) is connected to the inlet of the expander (1-7), the outlet of the expander (1-7) is connected to the heat release inlet of the low-pressure cooler (1-8), and the heat release side outlet of the low-pressure cooler (1-8) is connected to the inlet of the compressor (1-2). The heating system is connected to the heat-absorbing side of the high-pressure cooler (1-3), the heat-absorbing side of the low-pressure cooler (1-8), and the medium-temperature layer pipeline in the geothermal field (1-5). The solar thermal system is connected to the heat-releasing side of the carbon dioxide-molten salt heat exchanger (1-6).

2. The energy storage, power generation, and heating system coupling solar and geothermal energy according to claim 1, characterized in that, The heat release side outlet of the low-pressure cooler (1-8) is connected to the inlet of the compressor (1-2) via a flexible air chamber (1-1).

3. The energy storage, power generation, and heating system coupling solar and geothermal energy according to claim 1, characterized in that, The heat release side outlet of the high-pressure cooler (1-3) is connected to the inlet of the high-temperature layer pipeline in the geothermal field (1-5) via the liquid storage tank (1-4).

4. The energy storage, power generation, and heating system coupling solar and geothermal energy according to claim 1, characterized in that, The compressor (1-2) is connected to the motor (1-9); the expander (1-7) is connected to the generator (1-10).

5. The energy storage, power generation, and heating system coupling solar and geothermal energy according to claim 1, characterized in that, The heating system includes low-temperature user terminals (3-4) and cooling pumps (3-5); The outlet of the low-temperature user terminal (3-4) is divided into two paths after passing through the cooling pump (3-5). One path is connected to the inlet of the low-temperature user terminal (3-4) via the heat absorption side of the high-pressure cooler (1-3), and the other path is connected to the inlet of the low-temperature user terminal (3-4) via the heat absorption side of the low-pressure cooler (1-8).

6. The energy storage, power generation, and heating system coupling solar and geothermal energy according to claim 1, characterized in that, The heating system includes a high-temperature user end (3-1), a circulating pump (3-2), and a heat exchanger (3-3); The outlet of the mesothermal layer pipeline in the geothermal field (1-5) is connected to the inlet of the mesothermal layer pipeline in the geothermal field (1-5) via the heat absorption side of the heat exchanger (3-3), the high-temperature user end (3-1), and the circulating pump (3-2).

7. The energy storage, power generation, and heating system coupling solar and geothermal energy according to claim 1, characterized in that, The solar thermal system includes a solar collector (2-2), a high-temperature molten salt tank (2-3), and a low-temperature molten salt tank (2-4); The outlet of the high-temperature molten salt tank (2-3) is divided into two paths. One path is connected to the inlet of the low-temperature molten salt tank (2-4) via the heat release side of the heat exchanger (3-3), and the other path is connected to the inlet of the low-temperature molten salt tank (2-4) via the heat release side of the carbon dioxide-molten salt heat exchanger (1-6). The outlet of the low-temperature molten salt tank (2-4) is connected to the inlet of the solar collector (2-2), and the outlet of the solar collector (2-2) is connected to the inlet of the high-temperature molten salt tank (2-3).

8. The energy storage, power generation, and heating system coupling solar and geothermal energy according to claim 7, characterized in that, The outlet of the low-temperature molten salt tank (2-4) is connected to the inlet of the solar collector (2-2) via the molten salt pump (2-5).

9. The energy storage, power generation, and heating system coupling solar and geothermal energy according to claim 7, characterized in that, It also includes a heliostat (2-1), through which sunlight is reflected and then irradiated onto the solar collector (2-2).

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