A combined energy storage system and method of thermochemical energy storage and sensible heat energy storage

Abstract

The present invention discloses a combined energy storage system and method of thermochemical energy storage and sensible heat energy storage. The system includes a heat absorber, an industrial turbine, a compressor and a heat radiator. The gas outlet of the heat absorber is connected to the inlet of the industrial turbine, the outlet of the industrial turbine is connected to the gas inlet of the heat radiator, the gas outlet of the heat radiator is connected to the inlet of the compressor, and the outlet of the compressor is connected to the inlet of the heat absorber. The solid outlet of the heat absorber is connected to the solid inlet of the heat radiator, the solid outlet of the heat radiator is connected to the solid inlet of the heat absorber, a high-temperature gas storage tank is arranged between the gas outlet of the heat absorber and the inlet of the industrial turbine, a high-temperature silo is arranged between the solid outlet of the heat absorber and the solid inlet of the heat radiator, a low-temperature silo is arranged between the solid outlet of the heat radiator and the inlet of the heat absorber, and a cooler is arranged between the gas outlet of the heat radiator and the inlet of the compressor. The present invention combines thermochemical energy storage and sensible heat energy storage to achieve efficient storage and utilization of thermal energy.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage, and particularly relates to a combined energy storage system and method of thermochemical energy storage and sensible heat energy storage. Background Art

[0002] Sensible heat energy storage realizes energy storage through the change of the temperature of the energy storage medium. The energy storage medium is heated to increase its temperature, thereby storing thermal energy therein. The main energy storage media include high-temperature concrete, high-temperature molten salt, etc. Sensible heat energy storage is the energy storage form with the highest technical maturity and the most extensive application in the field of solar thermal power generation at present, and it is the mainstream energy storage technology for solar thermal power generation.

[0003] Thermochemical energy storage is mainly based on a reversible thermochemical reaction, and realizes energy storage and release through the breaking and recombination of chemical bonds. In the energy storage reaction, the energy storage material absorbs heat and decomposes into two substances for separate storage. When energy supply is required, the two substances come into full contact and react, converting the stored chemical energy into thermal energy and releasing it. Thermochemical energy storage has high energy storage density and efficiency, and is suitable for high-temperature and high-density storage of solar thermal energy. The volume and weight energy storage density of thermochemical energy storage are much higher than those of sensible heat or phase change heat storage. The energy storage carrier can be stored at room temperature for a long time. Thermochemical energy storage can usually obtain high-quality thermal energy. Most thermochemical energy storage carriers are safe, non-toxic, low in price, and easy to handle.

[0004] The sensible heat energy storage technology is simple, but has a low energy storage density. The thermochemical energy storage has a high energy storage density, but the technology is complex. Therefore, if a new system can be developed to combine sensible heat energy storage and thermochemical energy storage, the energy storage density will be greatly improved and the technical complexity will be reduced. Summary of the Invention

[0005] In order to overcome the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a combined energy storage system and method of thermochemical energy storage and sensible heat energy storage, which combines thermochemical energy storage and sensible heat energy storage, and can realize efficient storage and utilization of thermal energy.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A combined energy storage system of thermochemical energy storage and sensible heat energy storage includes an absorber 1. The gas outlet of the absorber 1 is connected to the inlet of an industrial turbine 4. The outlet of the industrial turbine 4 is connected to the gas inlet of a heat exchanger 6. The solid outlet of the heat exchanger 6 is connected to the solid inlet of the absorber 1; the solid outlet of the absorber 1 is connected to the solid inlet of the heat exchanger 6; the gas outlet of the heat exchanger 6 is connected to the inlet of a compressor 5. The outlet of the compressor 5 is connected to the inlet of the absorber 1; the industrial turbine 4 drives the compressor 5.

[0008] A high-pressure gas storage tank 3 is provided between the gas outlet of the heat absorber 1 and the inlet of the industrial turbine 4.

[0009] A high-temperature silo 2 is provided between the solid outlet of the heat absorber 1 and the solid inlet of the heat radiator 6.

[0010] A low-temperature silo 9 is provided between the solid outlet of the heat radiator 6 and the solid inlet of the heat absorber 1.

[0011] A cooler 7 is provided between the gas outlet of the heat radiator 6 and the inlet of the compressor 5.

[0012] A high-pressure gas storage tank 8 is provided between the outlet of the compressor 5 and the inlet of the heat absorber 1.

[0013] The energy storage method of a thermochemical energy storage and sensible heat combined energy storage system

[0014] Nitrogen entraining calcium hydroxide and heat storage particles enters the heat absorber 1, absorbs heat in the heat absorber 1, where calcium hydroxide is thermally decomposed to generate water vapor and calcium oxide, the heat storage particles are heated up, calcium oxide and the heat storage particles enter the high-temperature silo 2, nitrogen and water vapor enter the high-temperature gas storage tank 3, the high-temperature nitrogen and water vapor in the high-temperature gas storage tank 3 do work in the industrial turbine 4, the industrial turbine 4 drives the compressor 5 to operate, and the nitrogen and water vapor after doing work enter the heat radiator 6, the calcium oxide and heat storage particles in the high-temperature silo 2 enter the heat radiator 6, the water vapor and calcium oxide react to generate calcium hydroxide, releasing heat, the high-temperature heat storage particles release latent heat, after releasing heat, calcium hydroxide and the heat storage particles enter the low-temperature silo 9; nitrogen does not participate in the reaction, passes through the cooler 7 for cooling from the upper part of the heat radiator 6, enters the compressor 5 for compression, and enters the high-pressure gas storage tank 8 for storage after compression, the high-pressure nitrogen in the high-pressure gas storage tank 8 entraining calcium hydroxide and heat storage particles in the low-temperature silo 9 enters the heat absorber 1, calcium hydroxide absorbs heat and decomposes, and the heat storage particles absorb heat and are heated up to complete the cycle.

[0015] When the heat input is large, the sum of the heat absorption rate of the thermal decomposition of calcium hydroxide in the heat absorber 1 and the heat absorption rate of the heating up of the heat storage particles is greater than the sum of the heat release rate of the reaction between calcium oxide and water vapor in the heat radiator 6 and the heat release rate of the latent heat released by the heat storage particles, and the excessive calcium oxide and heat storage particles are stored in the high-temperature silo 2, and the excessive water vapor and nitrogen are stored in the high-temperature gas storage tank 3;

[0016] When there is no heat input, the nitrogen and water vapor stored in the high-temperature gas storage tank 3 continue to enter the industrial turbine 4 to do work. The industrial turbine 4 drives the compressor 5 to operate. After doing work, the nitrogen and water vapor enter the heat radiator 6. The calcium oxide and heat storage particles stored in the high-temperature silo 2 enter the heat radiator 6. The water vapor reacts with the calcium oxide to form calcium hydroxide, releasing heat. The high-temperature heat storage particles release latent heat. After releasing heat, the calcium hydroxide and heat storage particles enter the low-temperature silo 9. Nitrogen does not participate in the reaction. It passes through the cooler 7 and is cooled from the upper part of the heat radiator 6, then enters the compressor 5 for compression, and after compression, it enters the high-pressure gas storage tank 8 for storage. Since there is no heat input, the heat absorber 1 cannot work. The calcium hydroxide and heat storage particles are stored in the low-temperature silo 9, and the high-pressure nitrogen is stored in the high-pressure gas storage tank 8.

[0017] Advantages of the present invention:

[0018] When the combined thermal chemical energy storage and sensible heat energy storage system of the present invention is working specifically, the calcium hydroxide and heat storage particles are heated by the heat absorber, and the decomposed calcium oxide and high-temperature heat storage particles are stored. When the solar radiation is insufficient, the excess water vapor in the high-temperature gas storage tank, the excess calcium oxide and heat storage particles in the high-temperature silo are continuously sent into the heat radiator. The water vapor and calcium oxide carry out a chemical combination reaction, and the high-temperature heat storage particles release sensible heat, thus realizing the organic combination of thermal chemical energy storage and sensible heat energy storage.

[0019] In addition, the energy storage particles are doped in the calcium oxide and calcium hydroxide, which can effectively relieve the caking of the calcium oxide and calcium hydroxide and improve the cycle efficiency of the calcium oxide and calcium hydroxide. Description of the drawings

[0020] Figure 1 It is a schematic diagram of the system of the present invention.

[0021] Among them, 1 is the heat absorber, 2 is the high-temperature silo, 3 is the high-temperature gas storage tank, 4 is the industrial turbine, 5 is the compressor, 6 is the heat radiator, 7 is the cooler, 8 is the high-pressure gas storage tank, and 9 is the low-temperature silo. Specific embodiments

[0022] The present invention will be further described in detail below with reference to the drawings.

[0023] As Figure 1 shown, a combined thermal chemical energy storage and sensible heat energy storage system of the present invention includes a heat absorber 1, an industrial turbine 4, a compressor 5, and a heat radiator 6. The gas outlet of the heat absorber 1 is connected to the inlet of the industrial turbine 4, the outlet of the industrial turbine 4 is connected to the gas inlet of the heat radiator 6, the gas outlet of the heat radiator 6 is connected to the inlet of the compressor 5, and the outlet of the compressor 5 is connected to the inlet of the heat absorber 1.

[0024] The solid outlet of the heat absorber 1 is in communication with the solid inlet of the heat radiator 6.

[0025] The solid outlet of the heat radiator 6 is in communication with the solid inlet of the heat absorber 1.

[0026] As a preferred embodiment of the present invention, the present invention further includes a high-temperature gas storage tank 3 provided between the gas outlet of the heat absorber 1 and the inlet of the industrial turbine 4, a high-temperature silo 2 provided between the solid outlet of the heat absorber 1 and the solid inlet of the heat radiator 6, a low-temperature silo 9 provided between the solid outlet of the heat radiator 6 and the inlet of the heat absorber 1, a cooler 7 provided between the gas outlet of the heat radiator 6 and the inlet of the compressor 5, and a high-pressure gas storage tank 8 provided between the outlet of the compressor 5 and the inlet of the heat absorber 1.

[0027] Preferably, the heat absorber 1 is in the form of a fluidized bed, and the operating temperature is 600 - 700 °C.

[0028] Preferably, the heat radiator 6 is in the form of a fluidized bed or a moving bed reactor, and the operating temperature is 500 - 600 °C.

[0029] Preferably, the mass ratio of calcium hydroxide to the heat storage particles is 1:1.

[0030] Preferably, the heat storage particles are silicon carbide particles.

[0031] As Figure 1 shown, for the energy storage method of the combined energy storage system of thermochemical energy storage and sensible heat energy storage of the present invention, nitrogen entraining calcium hydroxide and heat storage particles enters the heat absorber 1, absorbs heat in the heat absorber 1, wherein calcium hydroxide is thermally decomposed to generate water vapor and calcium oxide, the heat storage particles are heated up, calcium oxide and the heat storage particles enter the high-temperature silo 2, nitrogen and water vapor enter the high-temperature gas storage tank 3, the high-temperature nitrogen and water vapor in the high-temperature gas storage tank 3 do work in the industrial turbine 4, the industrial turbine 4 drives the compressor 5 to operate, the nitrogen and water vapor after doing work enter the heat radiator 6, calcium oxide and the heat storage particles in the high-temperature silo 2 enter the heat radiator 6, water vapor and calcium oxide react to generate calcium hydroxide, releasing heat, the high-temperature heat storage particles release latent heat, after releasing heat, calcium hydroxide and the heat storage particles enter the low-temperature silo 9. Nitrogen does not participate in the reaction, passes through the cooler 7 for cooling from the upper part of the heat radiator 6, enters the compressor 5 for compression, and enters the high-pressure gas storage tank 8 for storage after compression, the high-pressure nitrogen in the high-pressure gas storage tank 8 entraining calcium hydroxide and heat storage particles in the low-temperature silo 9 enters the heat absorber 1, calcium hydroxide absorbs heat and decomposes, and the heat storage particles absorb heat and are heated up, completing the cycle.

[0032] When the heat input is large, the sum of the endothermic rate of calcium hydroxide decomposition in the heat absorber 1 and the endothermic rate of the heat storage particles heating up is greater than the sum of the exothermic rate of the reaction between calcium oxide and water vapor in the heat radiator 6 and the exothermic rate of the heat storage particles releasing latent heat. The excessive calcium oxide and heat storage particles are stored in the high-temperature silo 2, and the excessive water vapor and nitrogen are stored in the high-temperature gas storage tank 3.

[0033] When there is no heat input, the nitrogen and water vapor stored in the high-temperature gas storage tank 3 continue to enter the industrial turbine 4 to do work. The industrial turbine 4 drives the compressor 5. After doing work, the nitrogen and water vapor enter the heat radiator 6. The calcium oxide and heat storage particles stored in the high-temperature silo 2 enter the heat radiator 6. The water vapor and calcium oxide react to form calcium hydroxide, releasing heat. The high-temperature heat storage particles release latent heat. After releasing heat, the calcium hydroxide and heat storage particles enter the low-temperature silo 9. Nitrogen does not participate in the reaction. It passes through the cooler 7 and is cooled from the upper part of the heat radiator 6, then enters the compressor 5 for compression, and after compression, it enters the high-pressure gas storage tank 8 for storage. Since there is no heat input, the heat absorber 1 cannot work, and the calcium hydroxide and heat storage particles are stored in the low-temperature silo 9, and the high-pressure nitrogen is stored in the high-pressure gas storage tank 8.

[0034] It should be noted that the above embodiments are only for illustrating the technical concept and characteristics of the present invention. Specific implementation methods, such as the types of the heat absorber 1, the industrial turbine 4, and the heat radiator 6, as well as the operating temperatures of the heat absorber 1 and the heat radiator 6 and the mass ratio of calcium hydroxide to heat storage particles, etc., can still be modified and improved, but none of them will deviate from the scope and basic spirit of the present invention defined in the claims.

Claims

1. A method for energy storage in a combined energy storage system of thermochemical energy storage and sensible heat energy storage, characterized in that, The energy storage system includes an endothermic reactor (1). The gas outlet of the endothermic reactor (1) is communicated with the inlet of an industrial turbine (4). The outlet of the industrial turbine (4) is communicated with the gas inlet of an exothermic reactor (6). The solid outlet of the exothermic reactor (6) is communicated with the solid inlet of the endothermic reactor (1). The solid outlet of the endothermic reactor (1) is communicated with the solid inlet of the exothermic reactor (6). The gas outlet of the exothermic reactor (6) is communicated with the inlet of a compressor (5). The outlet of the compressor (5) is communicated with the inlet of the endothermic reactor (1). The industrial turbine (4) drives the compressor (5). A high-temperature gas storage tank (3) is arranged between the gas outlet of the endothermic reactor (1) and the inlet of the industrial turbine (4). A high-temperature storage bin (2) is arranged between the solid outlet of the endothermic reactor (1) and the solid inlet of the exothermic reactor (6). A low-temperature storage bin (9) is arranged between the solid outlet of the exothermic reactor (6) and the solid inlet of the endothermic reactor (1). Nitrogen gas entraining calcium hydroxide and heat storage particles enters the endothermic reactor (1), absorbs heat in the endothermic reactor (1). Among them, calcium hydroxide is thermally decomposed to generate water vapor and calcium oxide, and the heat storage particles are heated up. The calcium oxide and the heat storage particles enter the high-temperature storage bin (2), and the nitrogen gas and water vapor enter the high-temperature gas storage tank (3). The high-temperature nitrogen gas and water vapor in the high-temperature gas storage tank (3) do work in the industrial turbine (4). The industrial turbine (4) drives the compressor (5) to operate. The nitrogen gas and water vapor after doing work enter the exothermic reactor (6). The calcium oxide and heat storage particles in the high-temperature storage bin (2) enter the exothermic reactor (6). The water vapor and calcium oxide react to generate calcium hydroxide, releasing heat. The high-temperature heat storage particles release latent heat. After releasing heat, the calcium hydroxide and heat storage particles enter the low-temperature storage bin (9). Nitrogen gas does not participate in the reaction. It passes through a cooler (7) and is cooled from the upper part of the exothermic reactor (6), then enters the compressor (5) for compression, and after compression, it enters a high-pressure gas storage tank (8) for storage. The high-pressure nitrogen gas in the high-pressure gas storage tank (8) entraining the calcium hydroxide and heat storage particles in the low-temperature storage bin (9) enters the endothermic reactor (1). The calcium hydroxide absorbs heat and decomposes, and the heat storage particles absorb heat and are heated up to complete the cycle.

2. The energy storage method of a combined energy storage system of thermochemical energy storage and sensible heat energy storage according to claim 1, characterized in that, A cooler (7) is arranged between the gas outlet of the exothermic reactor (6) and the inlet of the compressor (5).

3. The energy storage method of a combined energy storage system of thermochemical energy storage and sensible heat energy storage according to claim 1, wherein A high-pressure gas storage tank (8) is arranged between the outlet of the compressor (5) and the inlet of the endothermic reactor (1).

4. The energy storage method of a combined energy storage system of thermochemical energy storage and sensible heat energy storage according to claim 1, characterized in that When the heat input is large, the sum of the heat absorption rates of the thermal decomposition of calcium hydroxide and the heating-up of the heat storage particles in the endothermic reactor (1) is greater than the sum of the heat release rates of the reaction between calcium oxide and water vapor and the release of latent heat by the heat storage particles in the exothermic reactor (6). The excess calcium oxide and heat storage particles are stored in the high-temperature storage bin (2), and the excess water vapor and nitrogen gas are stored in the high-temperature gas storage tank (3). When there is no heat input, the nitrogen and water vapor stored in the high-temperature gas storage tank (3) continue to enter the industrial turbine (4) to do work. The industrial turbine (4) drives the compressor (5) to operate. After doing work, the nitrogen and water vapor enter the heat release device (6). The calcium oxide and heat storage particles stored in the high-temperature silo (2) enter the heat release device (6). The water vapor reacts with the calcium oxide to form calcium hydroxide, releasing heat. The high-temperature heat storage particles release latent heat. After releasing heat, the calcium hydroxide and heat storage particles enter the low-temperature silo (9); nitrogen does not participate in the reaction. It passes through the cooler (7) for cooling from the upper part of the heat release device (6), then enters the compressor (5) for compression, and after compression, it enters the high-pressure gas storage tank (8) for storage. Since there is no heat input, the heat absorber (1) cannot work. The calcium hydroxide and heat storage particles are stored in the low-temperature silo (9), and the high-pressure nitrogen is stored in the high-pressure gas storage tank (8).

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