Heat storage system and heat storage method

Abstract

According to the heat storage system and the heat storage method, hot water heat storage and thermochemical heat storage of a thermochemical heat storage system are coupled, low-temperature heat is stored through pressurized water heat storage, high-temperature heat is subjected to thermochemical storage through a thermochemical heat storage material, and cascade heat storage is achieved. The invention provides a heat storage system. The heat storage system comprises a pressure-bearing hot water storage tank, a thermal chemical reaction device and a compression device. Wherein the thermochemical reaction device is internally provided with a thermochemical heat storage material, a product generated in a heat storage reaction of the thermochemical heat storage material comprises water, the product is in contact reaction with water to release heat in an exothermic reaction, and a gas inlet and a gas outlet of the thermochemical reaction device are communicated with the pressure-bearing hot water storage tank; and the compression device is arranged on a communicating pipeline between the gas outlet of the thermal chemical reaction device and the pressure-bearing hot water storage tank.

Description

Technical Field

[0001] The present invention relates to the field of heat storage technology, and in particular to a heat storage system and a heat storage method. Background Art

[0002] Water is one of the traditional heat storage media. Water heat storage has the advantages of simple equipment, long service life, and low investment. Common water heat storage includes non-pressurized water heat storage and pressurized water heat storage. Among them, non-pressurized energy storage has low energy density. The pressurized heat storage system can effectively increase the boiling point of water by increasing the system pressure, thereby increasing the energy storage density. However, as the boiling point of water increases, the saturation pressure of water increases more, which increases the cost of the pressure-resistant storage tank. Once the pressure in the hot water storage tank is lower than the saturation pressure of the hot water, the hot water will vaporize significantly, affecting the heat storage efficiency.

[0003] Compared with sensible heat storage, thermochemical heat storage has a higher heat storage density. For hydroxide / oxide heat storage materials, during the heat storage process, the hydroxide absorbs heat to decompose and dehydrate, releasing high-temperature steam. Taking the thermal decomposition and dehydration of 1 mole of calcium hydroxide as an example, the high-temperature water vapor generated is cooled to room temperature, and the heat released accounts for 42% of the total heat absorbed by the reaction. However, the steam density is small, and direct storage is difficult, which can easily cause energy loss or increase the cost of heat storage. After heat storage, the exothermic process of the hydroxide / oxide heat storage material (oxide) reacts with water vapor to release heat, so a large amount of water vapor needs to be provided, and the partial pressure of water vapor directly affects the exothermic temperature and heat release efficiency. Summary of the invention

[0004] In view of the above problems, the present invention provides a heat storage system and a heat storage method, which solve at least part of the above problems by coupling hot water heat storage with thermochemical heat storage system heat storage.

[0005] The first aspect of the present invention provides a heat storage system, which includes: a pressurized hot water storage tank, a thermochemical reaction device and a compression device. The thermochemical reaction device is equipped with a thermochemical heat storage material, the product generated in the heat storage reaction of the thermochemical heat storage material includes water, and the heat is released by contacting with water in the exothermic reaction, the gas inlet and gas outlet of the thermochemical reaction device are connected to the pressurized hot water storage tank; the compression device is arranged on the connecting pipeline between the gas outlet of the thermochemical reaction device and the pressurized hot water storage tank.

[0006] According to the heat storage system provided by the present invention, during the heat storage process, the thermochemical heat storage material built into the thermochemical reaction device absorbs heat, a heat storage reaction occurs to generate water vapor, the gas outlet of the thermochemical reaction device is opened, and the water vapor enters the compression device through the gas outlet of the thermochemical reaction device. After being compressed by the compression device, the high-pressure water vapor enters the pressurized hot water storage tank for storage.

[0007] During the heat release process, the gas inlet of the thermochemical reaction device is opened, and the high-pressure hot water stored in the pressurized hot water storage tank vaporizes to produce water vapor, which flows to the thermochemical reaction device. The thermochemical heat storage material built into the thermochemical reaction device contacts the water vapor to produce an exothermic reaction.

[0008] In the above manner, thermochemical heat storage and pressurized water heat storage are coupled, low-temperature heat is stored by pressurized water heat storage, and high-temperature heat is thermochemically stored by thermochemical heat storage materials, so as to realize step heat storage. In addition, the high-temperature water vapor generated when the thermochemical reaction device stores heat is passed into the pressurized hot water storage tank for heat storage, which can reduce the heat loss of water vapor. Furthermore, when storing heat, the setting of the compression device can better promote the pressurized water vapor to enter the pressurized hot water storage tank, and can increase the pressure of the pressurized hot water storage tank to maintain the pressure in the pressurized hot water storage tank higher than the saturation pressure of the hot water, thereby inhibiting the vaporization of hot water. Afterwards, when releasing heat, the water vapor in the pressurized hot water storage tank is used to supply the thermochemical reaction device, without the need for an external steam supply device, with small heat loss, high energy utilization rate, simple system device, and the water vapor released in the pressurized hot water storage tank can reduce the pressure increase in the pressurized hot water storage tank, thereby playing a role in constant pressure.

[0009] As a preferred technical solution of the present invention, the thermochemical heat storage material is a hydroxide / oxide heat storage material.

[0010] As a preferred technical solution of the present invention, the gas inlet of the thermochemical reaction device is connected to the steam outlet of the pressurized hot water storage tank, and the gas outlet of the thermochemical reaction device is connected to the steam inlet of the pressurized hot water storage tank.

[0011] According to the preferred technical solution of the present invention, the water vapor generated when the hydroxide stores heat can be re-introduced into the thermochemical reaction device for utilization during heat release, thereby realizing a closed cycle of the water vapor working medium, eliminating the need for external water vapor supply, and reducing pollution to the oxide particles (e.g., CO 2 The mixed gas will react with calcium oxide to form calcium carbonate, affecting the heat storage efficiency).

[0012] As a preferred technical solution of the present invention, the pressurized hot water storage tank contains hot water and inert gas, and the pressure in the pressurized hot water storage tank is greater than the atmospheric pressure.

[0013] According to the preferred technical solution of the present invention, the inert gas does not react with water and hydroxides / oxides and can be used to increase the pressure of the hot water storage tank, thereby increasing the heat storage density of the pressurized hot water storage tank.

[0014] As a preferred technical solution of the present invention, the heat storage system also includes a steam generator, the water inlet of the steam generator is connected to the hot water outlet of the pressurized hot water storage tank, and the steam outlet of the steam generator is connected to the gas inlet of the thermochemical reaction device.

[0015] According to the preferred technical solution of the present invention, hot water in the pressurized hot water storage tank can be directly drawn out to generate steam to supply the thermochemical reaction device, so that the steam supply to the thermochemical reaction device is stable and adjustable during the heat release process.

[0016] As a preferred technical solution of the present invention, the heat storage system also includes: a cold water storage tank, a first heat exchanger, a second heat exchanger, a heat supply pipeline and a heat absorption pipeline. Among them, the outlet and the inlet of the cold water storage tank are connected to the pressurized hot water storage tank; the first heat exchanger is arranged on the connecting pipeline between the inlet of the cold water storage tank and the pressurized hot water storage tank; the second heat exchanger is arranged on the connecting pipeline between the outlet of the cold water storage tank and the pressurized hot water storage tank; the heat supply pipeline is equipped with a flowing heat supply medium, the upstream section of the heat supply pipeline passes through the thermochemical reaction device for heat exchange, and the downstream section of the heat supply pipeline passes through the second heat exchanger for heat exchange; the heat absorption pipeline is equipped with a flowing heat absorption medium, the upstream section of the heat absorption pipeline passes through the first heat exchanger for heat exchange, and the downstream section of the heat supply pipeline passes through the thermochemical reaction device for heat exchange.

[0017] According to the preferred technical solution of the present invention, the cold water storage tank, the pressurized hot water storage tank, the first heat exchanger and the second heat exchanger form a complete water heat storage flow path, which can further utilize the waste heat of the heating pipeline after heat storage in the thermochemical reaction device for low-temperature heat storage, and before the heat absorption pipeline enters the thermochemical reaction device to absorb heat, the low-temperature heat storage water heat storage flow path is used to preheat the heat absorption medium, which is more conducive to the cascade heat storage of the heat storage system and reduces heat loss.

[0018] As a preferred technical solution of the present invention, the heat storage system further includes: a cold water pump and a hot water pump. The cold water pump is arranged between the outlet of the cold water storage tank and the hot water inlet of the pressurized hot water storage tank; the hot water pump is arranged between the inlet of the cold water storage tank and the hot water outlet of the pressurized hot water storage tank.

[0019] According to a preferred technical solution of the present invention, a water pump is used to drive the hot water and cold water to be transported between the pressurized hot water storage tank and the cold water storage tank.

[0020] As a preferred technical solution of the present invention, the heat storage system also includes: a pressure regulating device connected to the pressurized hot water storage tank and / or the cold water storage tank.

[0021] According to the preferred technical solution of the present invention, the cold water storage tank is connected to the pressure regulating device, and the air pressure in the cold water storage tank can be adjusted to be consistent with the pressure hot water storage tank, thereby reducing the power consumption of the cold water pump and the hot water pump. The pressure hot water storage tank is connected to the pressure regulating device, and the air pressure in the pressure hot water storage tank can be adjusted. Increasing the air pressure can increase the boiling point of hot water and increase the energy storage density; reducing the air pressure can vaporize the hot water and provide water vapor for the exothermic reaction of the thermochemical reaction device.

[0022] As a preferred technical solution of the present invention, the heat storage system also includes: a pressure balance pipeline connecting the upper parts of the pressurized hot water storage tank and the cold water storage tank.

[0023] According to the preferred technical solution of the present invention, the pressure balancing pipeline connects the pressurized hot water storage tank and the upper part of the cold water storage tank (i.e., the air part), so that the pressures in the two tanks can be the same. At this time, the pressure in the cold water storage tank is also greater than the atmospheric pressure, thereby reducing the power consumption of the water pump.

[0024] The second invention of the present invention also provides a heat storage method, comprising the following steps:

[0025] The heat storage step supplies heat to the thermochemical reaction device, opens the gas outlet of the thermochemical reaction device, opens the compression device, and causes the thermochemical heat storage material in the thermochemical reaction device to undergo a heat storage reaction to generate water vapor, which is compressed by the compression device and then passed into the pressurized hot water storage tank.

[0026] In the exothermic step, the thermochemical reaction device absorbs heat, the gas inlet of the thermochemical reaction device is opened, the thermochemical heat storage material in the thermochemical reaction device undergoes an exothermic reaction, the pressurized hot water storage tank supplies water vapor into the thermochemical reaction device, and the thermochemical heat storage material contacts and reacts with the water vapor. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of a heat storage system in a first embodiment of the present invention.

[0028] Figure 2 It is a structural schematic diagram of another heat storage system in the first embodiment of the present invention.

[0029] Figure 3 It is a structural schematic diagram of a more specific heat storage system according to the second embodiment of the present invention.

[0030] Figure 4 It is a structural schematic diagram of another more specific heat storage system according to the second embodiment of the present invention.

[0031] Figure 5 4 is a flow chart of a heat storage method provided in the third embodiment of the present invention.

[0032] Description of reference numerals: heating pipeline 100; heat absorption pipeline 200;

[0033] A pressurized hot water storage tank 1; a cold water storage tank 2; a thermochemical reaction device 3; a first heat exchanger 41; a second heat exchanger 42; a cold water pump 5; a hot water pump 6; a compression device 7; a steam generator 8; a pressure regulating device 9; and a pressure balance pipeline 10. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] First embodiment

[0036] Figure 1 Schematic diagram of the structure of the heat storage system provided in the first embodiment of the present invention. Figure 1 As shown, the heat storage system in this embodiment includes a pressurized hot water storage tank 1, a thermochemical reaction device 3 and a compression device 7.

[0037] The pressurized hot water storage tank 1 may be any pressure container, which stores pressurized hot water. The boiling point of water can be increased by pressurization, that is, the heat storage density of water can be increased. The pressurization method is not limited here, and the pressurization can be performed by adding water vapor, reducing the volume, or filling gas. Preferably, nitrogen or other gas that does not react with thermochemical heat storage materials and water can be filled into the pressurized hot water storage tank 1 to increase the pressure of the pressurized hot water storage tank 1.

[0038] The thermochemical reaction device 3 is equipped with a thermochemical heat storage material. In the present embodiment, the thermochemical heat storage material is preferably a heat storage material of a hydroxide / oxide system. The heat storage material of the hydroxide / oxide system undergoes a dehydration decomposition reaction when storing heat, and the hydroxide absorbs heat to produce oxides and water. Since the heat storage temperature is high, the product water is produced in the form of high-temperature water vapor. When releasing heat, the oxide and water undergo a hydration reaction under high temperature conditions to produce hydroxide and release a large amount of heat. The heat storage material of the hydroxide / oxide system has a high heat storage density and is environmentally friendly.

[0039] The compression device 7 can be any steam compressor. The inlet of the compression device 7 is connected to the gas outlet of the thermochemical reaction device 3, and the outlet of the compression device 7 is connected to the pressurized hot water storage tank 1, which is used to pressurize and transport the high-temperature steam generated when the thermochemical reaction device 3 stores heat to the pressurized hot water storage tank 1.

[0040] Specifically, if Figure 1 As shown, in this embodiment, the thermochemical reaction device 3 is bidirectionally connected to the pressurized hot water storage tank 1 to form a circulatory heat storage flow path.

[0041] In some preferred embodiments, the gas outlet of the thermochemical reaction device 3 is connected to the inlet of the compression device 7, the outlet of the compression device 7 is connected to the steam inlet of the pressurized hot water storage tank 1, and the steam outlet of the pressurized hot water storage tank 1 is connected to the thermochemical reaction device 3.

[0042] During the heat storage process, the hydroxide built into the thermochemical reaction device 3 absorbs heat, undergoes a heat storage reaction, and dehydrates and decomposes to produce water vapor and oxides. The gas outlet of the thermochemical reaction device 3 is opened, and the water vapor enters the compression device 7 from the gas outlet of the thermochemical reaction device 3. After being compressed by the compression device 7, the high-pressure water vapor enters the pressurized hot water storage tank 1 for storage. During the heat release process, the gas inlet of the thermochemical reaction device 3 is opened, and the high-pressure hot water stored in the pressurized hot water storage tank 1 vaporizes to produce a large amount of water vapor. The oxide built into the thermochemical reaction device 3 contacts the water vapor to undergo an exothermic reaction to produce hydroxides.

[0043] In the above manner, when storing heat, the high-pressure water vapor generated by the thermochemical heat storage material can increase the pressure in the pressurized hot water storage tank to maintain the pressure in the pressurized hot water storage tank higher than the saturation pressure of the hot water, thereby inhibiting the evaporation of the hot water. When releasing heat, the water vapor flows from the pressurized hot water storage tank to the thermochemical reaction device, which can reduce the pressure increase in the pressurized hot water storage tank, thereby playing a role in constant pressure.

[0044] In other preferred embodiments, Figure 2 As shown, the heat storage system further includes a steam generator 8 disposed between the hot water outlet of the pressurized hot water storage tank 1 and the gas inlet of the thermochemical reaction device 3, the water inlet of the steam generator 8 is connected to the hot water outlet of the pressurized hot water storage tank 1, and the steam outlet of the steam generator 8 is connected to the gas inlet of the thermochemical reaction device 3. Preferably, the water outlet of the steam generator 8 is connected to the pressurized hot water storage tank 1. During the heat release process, the gas inlet of the thermochemical reaction device 3 is opened, the hot water outlet of the pressurized hot water storage tank 1 is opened, the steam generator 8 receives hot water and generates a large amount of water vapor, the water vapor enters the thermochemical reaction device 3 from the steam outlet of the steam generator 8, and the excess hot water flows back to the pressurized hot water storage tank 1 from the water outlet of the steam generator 8.

[0045] Through the above method, thermochemical heat storage and pressurized water heat storage are coupled, low-temperature heat is stored by pressurized water heat storage, and high-temperature heat is stored thermochemically by hydroxide heat storage materials, so as to realize step heat storage. In addition, since the water vapor generated by the thermal decomposition of the hydroxide heat storage material carries high-temperature heat, water vapor is generally difficult to store. The high-temperature water vapor generated during the heat storage of the thermochemical reaction device 3 is passed into the pressurized hot water storage tank 1 for heat storage, which can reduce the heat loss of water vapor. Furthermore, the setting of the compression device 7 can better promote the pressurized water vapor to enter the pressurized hot water storage tank 1, increase the pressure of the hot water storage tank, and then increase the boiling point of the hot water, inhibit the vaporization of the hot water, and increase the energy storage density. Afterwards, when releasing heat, the water vapor in the pressurized hot water storage tank 1 is used to supply the thermochemical reaction device 3, without the need for an external steam supply device, the heat loss is small, the energy utilization rate is high, and the system device is simple.

[0046] Second embodiment

[0047] Figure 3 A more specific structural schematic diagram of a heat storage system provided by the second embodiment of the present invention is shown in FIG.

[0048] like Figure 3 As shown, the heat storage system provided by the second embodiment of the present invention also includes a cold water storage tank 2, a first heat exchanger 41, a second heat exchanger 42, a heating pipeline 100, a heat absorption pipeline 200, a cold water pump 5 and a hot water pump 6.

[0049] The outlet of the cold water storage tank 2 is connected to the cold water inlet of the second heat exchanger 42 via the cold water pump 5, and the hot water outlet of the second heat exchanger 42 is connected to the hot water inlet of the pressurized hot water storage tank 1. The hot water outlet of the pressurized hot water storage tank 1 is connected to the hot water inlet of the first heat exchanger 41 via the hot water pump 6, and the cold water outlet of the first heat exchanger 41 is connected to the inlet of the cold water storage tank 2.

[0050] In particular, in the present embodiment, a flowing heat supply medium is built into the heat supply pipeline 100, and the upstream section of the heat supply pipeline 100 passes through the thermochemical reaction device 3 for heat exchange, and the downstream section of the heat supply pipeline 100 passes through the second heat exchanger 42 for heat exchange, so that in the heat storage process of the heat storage system of the present embodiment, the high-temperature heat supply medium first flows through the thermochemical reaction device 3, and then flows through the second heat exchanger 42 to exchange heat with the low-temperature cold water at the outlet of the cold water storage tank 2. A flowing heat absorption medium is built into the heat absorption pipeline 200, and the upstream section of the heat absorption pipeline 200 passes through the first heat exchanger 41 for heat exchange, and the downstream section of the heat supply pipeline 100 passes through the thermochemical reaction device 3 for heat exchange, so that in the heat release process of the heat storage system of the present embodiment, the low-temperature heat absorption medium first flows through the first heat exchanger 41 to exchange heat with the hot water flowing out of the hot water outlet of the pressurized hot water storage tank 1, and then flows through the thermochemical reaction device 3 to absorb heat.

[0051] Through the above methods, low-temperature heat can be stored by the pressurized hot water heat storage system, and high-temperature heat can be stored by the hydroxide / oxide heat storage material, which can better realize cascade heat storage and broaden the energy storage temperature range of the heat storage system.

[0052] In some optional embodiments, the heating pipeline 100 and the heat absorption pipeline 200 can be a whole connected energy conversion circulation pipeline, or two separate external pipelines, and the heating medium and the heat absorption medium can be compressed air, water vapor, flue gas and other gases or fluids carrying heat sources.

[0053] Among them, preferably, the heat storage system in this embodiment also includes a hot water pump 6 and a cold water pump 5, and the direction and power of water flow are provided by the hot water pump 6 and the cold water pump 5.

[0054] In some optional embodiments, the upper part (air part) of the pressurized hot water storage tank 1 and the cold water storage tank 2 can be connected through a pressure balance pipeline 10 to make the pressure of the pressurized hot water storage tank 1 and the cold water storage tank 2 equal. At this time, the pressure in the cold water storage tank 2 is also greater than the atmospheric pressure, thereby reducing the power consumption of the water pump.

[0055] In some other optional embodiments, Figure 4 As shown, the heat storage system may further include two pressure regulating devices 9, the specific structure of the pressure regulating device is not limited. In a preferred embodiment, the pressure regulating device 9 may be a pressure tank, a telescopic chamber or the like. The cold water storage tank 2 is connected to the pressure regulating device 9, and the air pressure in the cold water storage tank 2 may be adjusted to be consistent with the pressurized hot water storage tank 1, thereby reducing the power consumption of the cold water pump 5 and the hot water pump 6.

[0056] The pressurized hot water storage tank 1 is connected to a pressure regulating device 9, which can adjust the air pressure in the pressurized hot water storage tank 1. Increasing the air pressure in the pressurized hot water storage tank 1 can increase the boiling point of hot water and increase the energy storage density; reducing the air pressure can vaporize the hot water and supply water vapor to the thermochemical reaction device 3.

[0057] [Third embodiment]

[0058] Figure 5 is a flow chart of the heat storage method provided in this embodiment. Figure 5 As shown, the heat storage method provided by the embodiment of the present invention includes the following cycle steps:

[0059] Heat storage step S1, supplying heat to the thermochemical reaction device 3, the gas outlet of the thermochemical reaction device 3 is opened, the compression device 7 is started, the thermochemical heat storage material in the thermochemical reaction device 3 undergoes a heat storage reaction to generate water vapor, which is compressed by the compression device 7 and then passed into the pressurized hot water storage tank 1;

[0060] In the heat release step S2, the thermochemical reaction device 3 absorbs heat, the gas inlet of the thermochemical reaction device 3 is opened, the thermochemical heat storage material in the thermochemical reaction device 3 undergoes an exothermic reaction, the pressurized hot water storage tank 1 supplies water vapor into the thermochemical reaction device 3, and the thermochemical heat storage material contacts and reacts with the water vapor.

[0061] The following combination Figure 3 and Figure 5 The heat storage method provided by the embodiment of the present invention is illustrated by way of example.

[0062] Heat storage step S1: The high-temperature heat medium first flows through the thermochemical reaction device 3 in the heat supply pipeline 100, without contacting the thermochemical heat storage material, and flows into the second heat exchanger 42 at a medium temperature after heating the thermochemical heat storage material (hydroxide), and flows out at a low temperature after exchanging heat with the cold water flowing out of the cold water storage tank 2. The cold water flowing out of the cold water storage tank 2 is transported by the cold water pump 5 and flows into the second heat exchanger 42, and the hot water after absorbing heat flows into the pressurized hot water storage tank 1. The hydroxide decomposes to produce water vapor and oxides after absorbing heat in the thermochemical reaction device 3, and the oxides are stored in the thermochemical reaction device 3. The water vapor enters the pressurized hot water storage tank 1 from the gas outlet of the thermochemical reaction device 3, increasing the pressure of the pressurized hot water storage tank 1, thereby increasing the boiling point of the hot water in the pressurized hot water storage tank 1, that is, increasing the heat storage density in the pressurized hot water storage tank 1.

[0063] Heat release step S2: The low-temperature heat-absorbing medium first flows through the first heat exchanger 41 in the heat-absorbing pipeline 200 to absorb heat, and then flows into the thermochemical reaction device 3 at a medium temperature without contacting the thermochemical heat storage material. After absorbing the heat released by the reaction of the thermochemical heat storage material (the reaction of the oxide and the water vapor under high temperature conditions), it flows out at a high temperature. Hot water flows out of the pressurized hot water storage tank 1 through the hot water pump 6 and flows into the first heat exchanger 41. After releasing heat, it enters the cold water storage tank 2 in a cold water state. The water vapor in the pressurized hot water storage tank 1 flows into the thermochemical reaction device 3, reacts with the oxide in the thermochemical reaction device 3, releases heat to generate hydroxide, and is stored in the thermochemical reaction device 3. The remaining high-temperature gas can return to the pressurized hot water storage tank 1.

[0064] So far, the technical solution of the present invention has been described in conjunction with the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to the above specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A heat storage system, It is characterized in that include: Pressurized hot water storage tanks; A thermochemical reaction device, having a thermochemical heat storage material built therein, wherein the product generated by the thermochemical heat storage material in the heat storage reaction includes water, and the product releases heat by contacting with water in the exothermic reaction, and the gas inlet and the gas outlet of the thermochemical reaction device are connected to the pressurized hot water storage tank; The compression device is arranged on the connecting pipeline between the gas outlet of the thermochemical reaction device and the pressurized hot water storage tank.

2. The heat storage system according to claim 1, It is characterized in that The thermochemical heat storage material is a hydroxide / oxide heat storage material.

3. The heat storage system according to claim 2, It is characterized in that The gas inlet of the thermochemical reaction device is communicated with the steam outlet of the pressurized hot water storage tank; the gas outlet of the thermochemical reaction device is communicated with the steam inlet of the pressurized hot water storage tank.

4. The heat storage system according to claim 3, It is characterized in that The pressurized hot water storage tank contains hot water and inert gas, and the pressure inside the pressurized hot water storage tank is greater than atmospheric pressure.

5. The heat storage system according to claim 2, It is characterized in that Also includes: A steam generator, wherein the water inlet of the steam generator is connected to the hot water outlet of the pressurized hot water storage tank, and the steam outlet of the steam generator is connected to the gas inlet of the thermochemical reaction device.

6. The heat storage system according to claim 2, It is characterized in that Also includes: A cold water storage tank, the outlet and the inlet of which are in communication with the pressurized hot water storage tank; A first heat exchanger is arranged on the connecting pipeline between the inlet of the cold water storage tank and the pressurized hot water storage tank; A second heat exchanger is provided on the connecting pipeline between the outlet of the cold water storage tank and the pressurized hot water storage tank; A heat supply pipeline having a flowing heat supply medium therein, wherein an upstream section of the heat supply pipeline passes through the thermochemical reaction device for heat exchange, and a downstream section of the heat supply pipeline passes through the second heat exchanger for heat exchange; The heat absorption pipeline has a flowing heat absorption medium therein, the upstream section of the heat absorption pipeline passes through the first heat exchanger for heat exchange, and the downstream section of the heat supply pipeline passes through the thermochemical reaction device for heat exchange.

7. The heat storage system according to claim 6, It is characterized in that Also includes: A cold water pump, arranged between the outlet of the cold water storage tank and the hot water inlet of the pressurized hot water storage tank; The hot water pump is arranged between the inlet of the cold water storage tank and the hot water outlet of the pressurized hot water storage tank.

8. The heat storage system according to claim 7, It is characterized in that Also includes: A pressure regulating device is connected to the pressurized hot water storage tank and / or the cold water storage tank.

9. The heat storage system according to claim 7, It is characterized in that Also includes: A pressure balance pipeline is connected to the upper part of the pressurized hot water storage tank and the cold water storage tank.

10. A heat storage method, It is characterized in that The following steps are involved: a heat storage step, supplying heat to the thermochemical reaction device, opening the gas outlet of the thermochemical reaction device, starting the compression device, causing the thermochemical heat storage material in the thermochemical reaction device to undergo a heat storage reaction to generate water vapor, which is compressed by the compression device and then passed into the pressurized hot water storage tank; In the heat release step, the thermochemical reaction device absorbs heat, the gas inlet of the thermochemical reaction device is opened, the thermochemical heat storage material in the thermochemical reaction device undergoes an exothermic reaction, the pressurized hot water storage tank supplies water vapor into the thermochemical reaction device, and the thermochemical heat storage material contacts and reacts with the water vapor.

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