A thermo-chemical energy storage system coupled with steam enthalpy augmentation

Abstract

A kind of coupling steam enthalpy increase's thermochemical energy storage system, including thermochemical energy storage device and saturated steam-water energy storage device connected by pipeline;Thermochemical energy storage device utilizes chemical enthalpy change and sensible heat physical enthalpy change to store electric energy and release in the form of heat energy;The saturated steam-water energy storage device stores electric energy and steam by means of latent heat physical enthalpy change and releases in the form of heat energy and steam;Thermochemical energy storage device and saturated steam-water energy storage device carry out simultaneously.The present application realizes high energy density, large-scale, low-cost, portable and efficient electric energy storage and heat energy output by coupling steam enthalpy increase's thermochemical energy storage technology;Meanwhile, the energy storage system is reasonably integrated, the product steam of energy storage process is effectively recycled for subsequent energy release process, the dependence on external material source is avoided, and energy efficiency is improved;The thermochemical energy storage system with good integrity can realize that energy storage process and energy release process belong to two places, is easy to deploy, and expands more application scenarios.

Description

Technical Field

[0001] This invention relates to the field of thermochemical energy storage technology, and more specifically to a thermochemical energy storage system coupled with vapor enthalpy enhancement. Background Technology

[0002] Renewable energy is often intermittent and unstable, which leads to a mismatch between peak renewable energy generation and peak energy consumption in time and space, resulting in a lot of energy waste. Therefore, there is a need for efficient and low-cost methods to flexibly absorb green electricity and off-peak electricity.

[0003] Thermal energy storage technology, leveraging applications such as auxiliary thermal power plant retrofitting, thermal energy storage-type solar thermal power plants, and the broad demand for industrial steam supply and residential heating, has become an economically viable energy storage form due to its low cost. Thermal energy storage technologies can be mainly divided into three categories based on their principles: sensible heat storage, phase change heat storage, and chemical heat storage (thermochemical energy storage). Among these, thermochemical energy storage technology boasts advantages such as high energy density, long storage time, and low energy loss. Among the various media used in thermochemical energy storage, the CaO / Ca(OH)2 system stands out as one of the most promising thermochemical energy storage systems due to its readily available raw materials, low cost, non-toxicity, adaptable operating temperatures for a wide range of applications, and high energy density of up to 104.4 kJ / mol. Utilizing a thermochemical energy storage system based on the CaO / Ca(OH)2 system, high-density, large-scale, and low-cost electrical energy storage and thermal energy output can be achieved, serving as an effective comprehensive solution for current green electricity / off-peak electricity consumption and green heating / cooling issues.

[0004] However, current thermochemical energy storage technology is hampered by insufficient technological maturity. Its devices and systems are often overly complex and cumbersome in design, difficult to operate and maintain, and also difficult to transport, limiting the mobile and distributed application of thermochemical energy storage systems. Currently, in CaO / Ca(OH)2 thermochemical energy storage systems, the superheated product steam generated during energy storage often cannot be fully recovered and utilized, resulting in a double loss of both matter and energy. Furthermore, during energy release, it relies on an external steam source to provide reactant steam to drive the energy release hydration reaction, greatly limiting its application scenarios. Summary of the Invention

[0005] To overcome the shortcomings of the existing technologies, this invention provides a thermochemical energy storage system coupled with steam enthalpy enhancement. The system integrates a thermochemical energy storage device and a saturated steam-water energy storage device to achieve high-energy-density, large-scale, low-cost, and portable high-efficiency electrical energy storage and thermal energy output using thermochemical energy storage technology coupled with steam enthalpy enhancement. Simultaneously, the system rationally integrates the energy storage system to effectively recover the product steam from the energy storage process for subsequent energy release, avoiding dependence on external material sources and improving energy efficiency. This well-integrated thermochemical energy storage system allows the energy storage and energy release processes to be located in separate sites, facilitating deployment and expanding application scenarios.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A thermochemical energy storage system coupled with steam enthalpy enhancement includes a thermochemical energy storage device and a saturated steam-water energy storage device connected by pipelines.

[0008] The thermochemical energy storage device uses chemical enthalpy change and sensible thermal physical enthalpy change to store electrical energy and release it in the form of heat energy;

[0009] The saturated steam-water energy storage device stores electrical energy and steam by means of latent heat physical enthalpy change and releases them in the form of heat energy and steam.

[0010] Thermochemical energy storage devices and saturated steam-water energy storage devices can simultaneously store electrical energy and release thermal energy.

[0011] Thermochemical energy storage devices and saturated steam-water energy storage devices construct reversible thermochemical reaction relationships through steam.

[0012] The thermochemical energy storage device is equipped with a steam pipe, which is connected to a steam compressor. The steam compressor is connected to the first port of a three-way valve three through a pipeline. The second port of the three-way valve three is connected to the inlet of the heat exchange tube two inside the saturated steam-water energy storage device. The third port is used to introduce the heat transfer fluid two.

[0013] The steam pipeline is equipped with an electric control valve, a three-way valve one, and a three-way valve two; a pipeline from the three-way valve one is connected to the first port of the three-way valve four, the second port of the three-way valve four is connected to the outlet of the heat exchange tube two on the saturated steam-water energy storage device, and the third port is used to discharge the heat transfer fluid.

[0014] The electric control valve is used to control the flow of product vapor from the dehydration reaction and reactant vapor from the hydration reaction by controlling the valve opening, as well as the pressure of the thermochemical energy storage device 1 and the saturated steam-water energy storage device.

[0015] The three-way valve is used to control the flow direction of the product vapor of the dehydration reaction and the reactant vapor of the hydration reaction.

[0016] The three-way valve 2 is used to control the steam inlet and outlet of the saturated steam-water energy storage device;

[0017] The three-way valves three and four are used to control the flow of the product vapor of the dehydration reaction during the energy storage process and the flow of the heat transfer fluid two in the heat exchange tube two during the energy release process.

[0018] The thermochemical energy storage device includes a shell, and inside the shell, a CaO / Ca(OH)2 system thermochemical energy carrier packing, a heat exchange tube, and an electric heater.

[0019] The CaO / Ca(OH)2 system thermochemical energy carrier filler is an energy carrier particle made by freeze drying and granulation process. Its initial main component is Ca(OH)2. Doping with appropriate thermally conductive strengthening materials can enhance the internal heat transfer of the thermochemical energy storage device and improve the system performance. Doping with appropriate binders can enhance the mechanical strength of the energy carrier particles and avoid the problems of energy carrier particle breakage and agglomeration.

[0020] The heat exchange tube and the electric heater are both embedded in the CaO / Ca(OH)2 system thermochemical energy carrier packing. The heat exchange tube and the electric heater are interconnected by metal fins to form a heat transfer network to enhance the internal heat transfer of the thermochemical energy storage device 1 and improve the system performance.

[0021] The saturated steam-water energy storage device includes a level gauge, a second heat exchange tube, saturated steam, and saturated water.

[0022] The saturated steam-water energy storage device has saturated water at the bottom and saturated steam at the top. The second heat exchange tube is located at the bottom of the saturated steam-water energy storage device. The level of the saturated water is monitored by a level gauge to ensure that the second heat exchange tube is always below the saturated water level, so as to achieve full heat exchange between the second heat exchange tube and the saturated water.

[0023] An operation method for a thermochemical energy storage system coupled with vapor enthalpy enhancement, comprising an energy storage process and an energy release process;

[0024] The energy storage process takes place at a location with a power supply and where energy is stored, and includes the following steps:

[0025] First, the electric heater is turned on to heat the Ca(OH)2 thermochemical energy carrier packing material in the thermochemical energy storage device. It absorbs heat and rises in temperature from the initial environmental state (state point a, 20℃, 1 atm), realizing the storage of electrical energy through sensible enthalpy change. When the temperature reaches the reaction conditions (state point b, 505℃, 1 atm), the dehydration reaction occurs, absorbing the chemical reaction enthalpy and generating CaO, realizing the storage of electrical energy through chemical reaction enthalpy change, while releasing superheated steam (state point b, 505℃, 1 atm).

[0026] Then, the electric control valve, three-way valve one, three-way valve two, three-way valve three, and three-way valve four are opened to allow superheated steam (state point b, 505℃, 1 atm) to flow out of the thermochemical energy storage device. It then flows sequentially through the electric control valve, three-way valve one, and three-way valve four into heat exchange tube two. The superheated steam exchanges heat and increases the enthalpy of the saturated water in the saturated steam-water energy storage device, which is at ambient temperature (state point c, 20℃, 0.023 atm). After the superheated steam flows out of heat exchange tube two, it flows through three-way valve three into the steam compressor for compression and enthalpy increase. Then it flows through three-way valve two into the saturated steam-water energy storage device to mix with the saturated steam, and together they reach a high-enthalpy saturated steam-water state (state point d, 160℃, 6 atm). This achieves the equivalent storage of electrical energy through latent heat physical enthalpy change, while simultaneously storing steam.

[0027] Finally, the electric control valve and electric heater are shut off, and the energy storage process is now complete.

[0028] The energy release process takes place at a location with a demand for thermal energy and includes the following steps:

[0029] First, open three-way valve one and three-way valve two, and control the opening degree of the electric control valve to release saturated steam (state point e, 100℃, 1atm) from the original saturated steam-water state (state point d, 160℃, 6atm) of the saturated steam-water energy storage device. The steam enters the thermochemical energy storage device, contacts the CaO thermochemical energy carrier packing, drives the hydration reaction, generates Ca(OH)2, and releases the chemical reaction enthalpy in the form of heat energy (state point b, 505℃, 1atm). At the same time, heat transfer fluid one is introduced into heat exchange tube one to extract heat, realizing the release of heat energy through the change of chemical reaction enthalpy. By adjusting the flow rate of heat transfer fluid one, the heat extraction power is controlled to obtain heat transfer fluid one at different temperatures.

[0030] Then, when the hydration reaction is complete, the heat transfer fluid continues to pass through the heat exchange tube to extract heat until the temperature of the Ca(OH)2 thermochemical energy carrier packing returns to its initial state (state point a, 20℃, 1 atm), thus realizing the release of heat energy through the sensible enthalpy change of the material.

[0031] Finally, open three-way valves three and four to allow heat transfer fluid two to be introduced into heat exchange tube two for heat extraction. This reduces the enthalpy of the remaining saturated steam-water (state point e, 100℃, 1 atm) in the saturated steam-water energy storage device until it returns to the initial saturated steam-water state (state point c, 20℃, 0.023 atm), thus releasing heat energy through latent heat physical enthalpy change. During this process, the flow rate of heat transfer fluid two is adjusted by regulating the opening of three-way valve three, thereby controlling the heat extraction power and obtaining heat transfer fluid two at different temperatures. At this point, the energy release process is complete.

[0032] Depending on the site conditions and requirements, different fluids such as liquid water, steam, air, and heat transfer oil can be used for heat transfer fluid 2.

[0033] During the energy storage process, the liquid level gauge is used to monitor and ensure that there is always a free liquid surface in the saturated steam-water energy storage device, that is, it is always in a steam-water two-phase state.

[0034] During the energy release process, the liquid level gauge is used to monitor and ensure that there is always a free liquid surface in the saturated steam-water energy storage device, that is, it is always in a steam-water two-phase state.

[0035] The beneficial effects of this invention are:

[0036] 1. The thermochemical energy storage device in this invention uses a CaO / Ca(OH)₂ system thermochemical energy carrier filler. This energy carrier material system has the characteristics of high reaction enthalpy (104.4 kJ / mol), non-toxicity, high storage safety, and low material cost. Using the CaO / Ca(OH)₂ system thermochemical energy carrier as filler enables the energy storage system to achieve high-density, safe, large-scale, and low-cost energy storage. With the CaO / Ca(OH)₂ system thermochemical energy carrier as filler, steam participates in both the dehydration reaction during energy storage and the hydration reaction during energy release, ensuring full integration with the saturated steam-water energy storage device. Using energy carrier particles prepared through freeze-drying and granulation processes, and supplementing them with appropriate proportions of thermally conductive strengthening materials and binders according to different scenario requirements, can improve the performance of the energy storage system and avoid the problems of energy carrier particle breakage and agglomeration.

[0037] 2. In this invention, the thermochemical energy storage device and the saturated steam-water energy storage device are used in combination. The saturated steam-water energy storage device can provide the thermochemical energy storage device with the reactant steam required to drive the hydration reaction during the energy release process. This makes the energy storage system not require an external steam source to provide reactant steam to drive the thermochemical reaction, thus avoiding dependence on the external environment and making the thermochemical energy storage system suitable for more application scenarios.

[0038] 3. In this invention, the thermochemical energy storage device and the saturated steam-water energy storage device are used in combination. The product steam generated by the dehydration reaction during the energy storage process of the thermochemical energy storage device can be stored in the saturated steam-water energy storage device. This avoids the direct discharge and loss of steam, and at the same time, the physical enthalpy in the superheated product steam can also be stored in the saturated steam-water energy storage device, which effectively improves the energy efficiency of the energy storage system.

[0039] 4. This invention avoids dependence on external steam sources, boasts excellent integration, and can be transported and moved between different locations with varying needs, enabling the energy storage and release processes to be carried out remotely. It allows for the on-site consumption and storage of green electricity / off-peak electricity, which can then be transported to factories, residential areas, and other locations requiring heat energy for user release as needed.

[0040] 5. This invention can output hot fluids at different temperatures for use, and has a variety of applications and scenarios.

[0041] 6. In this invention, the thermochemical energy storage device and the saturated steam-water energy storage device are used in combination to efficiently couple chemical and physical methods, so as to realize the storage of energy in multiple forms of chemical reaction enthalpy and physical enthalpy, which can fully expand the scale of energy storage system. Attached Figure Description

[0042] Figure 1 A schematic diagram of a thermochemical energy storage system with coupled steam enthalpy enhancement provided by the present invention.

[0043] Figure 2 This invention provides a schematic diagram of the process and operating points of a thermochemical energy storage system with coupled steam enthalpy enhancement during the energy storage process.

[0044] Figure 3 This invention provides a schematic diagram of the process and operating points of a thermochemical energy storage system with coupled steam enthalpy enhancement during the energy release process.

[0045] Figure label:

[0046] 1. Thermochemical energy storage device; 2. Saturated steam-water energy storage device; 3. Steam compressor; 4. Electric control valve; 5. Three-way valve one; 6. Three-way valve two; 7. Three-way valve three; 8. CaO / Ca(OH)2 system thermochemical energy carrier packing; 9. Heat exchange tube one; 10. Electric heater; 11. Liquid level gauge; 12. Heat exchange tube two; 13. Saturated steam; 14. Saturated water; 15. Detailed Implementation

[0047] The present invention will now be described in further detail with reference to the accompanying drawings.

[0048] like Figure 1 As shown, a thermochemical energy storage system coupled with steam enthalpy enhancement includes a thermochemical energy storage device 1, a saturated steam-water energy storage device 2, a steam compressor 3, an electric control valve 4, a three-way valve one 5, a three-way valve two 6, a three-way valve three 7, and a three-way valve four 8, wherein:

[0049] The thermochemical energy storage device 1 achieves efficient energy storage and release through a reversible reaction between calcium hydroxide (Ca(OH)2) and calcium oxide (CaO);

[0050] The saturated steam-water energy storage device 2 can store the product steam generated by the thermochemical energy storage device 1 in the reversible reaction process, and supply the reactant steam required by the thermochemical energy storage device 1 in the reversible reaction process, thereby avoiding dependence on external steam sources and realizing the storage of the thermal energy contained in the product steam.

[0051] The steam compressor 3 is used to compress and increase the enthalpy of steam, thereby storing electrical energy through physical enthalpy change.

[0052] The electric control valve 4 is used to control the pressure and steam flow of the thermochemical energy storage device 1 and the saturated steam-water energy storage device 2.

[0053] The thermochemical energy storage device 1 includes a CaO / Ca(OH)2 system thermochemical energy carrier packing 9, a heat exchange tube 10, and an electric heater 11.

[0054] The Ca(OH)2 thermochemical energy carrier packing 9 serves as an energy carrier. During the energy storage process, it is heated by the electric heater 11, converting electrical energy into sensible heat of the energy carrier and into chemical enthalpy through a reversible thermochemical reaction, thus achieving energy storage. During the energy release process, the CaO thermochemical energy carrier packing 9 undergoes a thermochemical reaction with the reactant vapor to release the chemical enthalpy. The released heat energy is absorbed and utilized by the heat transfer fluid in the heat exchange tube 10.

[0055] The saturated steam-water energy storage device 2 includes a level gauge 12, a heat exchange tube 13, saturated steam 14, and saturated water 15;

[0056] Heat exchange tube 2 13 is used to extract heat from heat transfer fluid 2 during the energy release process, and to extract the physical enthalpy stored in the mixture of saturated steam 14 and saturated water 15 in the form of thermal energy.

[0057] The level gauge 12 is used to monitor the liquid level of saturated water 15 inside the saturated steam-water energy storage device 2, ensuring that there is always a free liquid surface during the energy storage and release process, that is, it is always in a steam-water two-phase state.

[0058] This coupled steam enthalpy-enhancing thermochemical energy storage system can be moved to different locations to operate according to different needs. It has two different operating modes: energy storage and energy release. Taking typical operating conditions as an example:

[0059] During energy storage, the system is located at an energy storage site with both power supply capacity and energy storage demand. For example... Figure 2 As shown, firstly, the electric control valve 4 and the electric heater 11 are opened to use electrical energy to heat the Ca(OH)2 thermochemical energy carrier packing 9 in the thermochemical energy storage device 1. The Ca(OH)2 thermochemical energy carrier packing 9 is heated from an initial environmental state of 20℃ (state point a) to 505℃, i.e., state point b, realizing the storage of electrical energy through physical enthalpy change; with further heating, the thermochemical Ca(OH)2 thermochemical energy carrier packing 9 undergoes a dehydration reaction at 505℃ to generate CaO and absorbs chemical reaction enthalpy, realizing the storage of electrical energy through chemical reaction enthalpy change.

[0060] The superheated product steam (state point b) generated in the dehydration reaction at 505℃ and 1 atm is enthalped by adjusting three-way valves 5, 6, 7, and 8. This product steam passes through heat exchange tube 13 to exchange heat with saturated water 15 in the saturated steam-water energy storage device 2 at 20℃ and 0.023 atm (state point c), increasing its enthalpy. It then passes through steam compressor 3 for further compression and enthalpy increase before entering the saturated steam-water energy storage device 2 to mix with saturated steam 14, achieving a high enthalpy saturated steam-water state (state point d) at 160℃ and 6 atm. This achieves the equivalent storage of electrical energy through latent heat enthalpy change, while simultaneously storing steam. Finally, the electric control valve 4 and electric heater 11 are closed. The energy storage process is thus complete. Throughout this process, the level gauge 11 monitors the saturated steam-water energy storage device 2 to ensure a free liquid surface is always present, maintaining a steam-water two-phase state.

[0061] During the energy release process, the system is moved to an energy release location that has a demand for thermal energy supply.

[0062] like Figure 3 As shown, firstly, the electric control valve 4 is opened, and the three-way valves 5 and 6 are adjusted to release saturated steam at 100°C and 1 atm from the original high enthalpy saturated steam-water state of 160°C and 6 atm (state point d). This steam enters the thermochemical energy storage device 1 and comes into contact with the CaO thermochemical energy carrier packing 9, driving the hydration reaction to generate Ca(OH)2 and release the chemical reaction enthalpy in the form of heat energy (state point b). At the same time, the heat transfer fluid is passed through the heat exchange tube 10 to extract heat, realizing the release of heat energy through the enthalpy change of the chemical reaction. Then, when the hydration reaction is completed, the heat transfer fluid continues to pass through the heat exchange tube 10 to extract heat until the temperature of the Ca(OH)2 thermochemical energy carrier packing 9 returns to the initial state of 20°C (state point a), realizing the release of heat energy through the physical enthalpy change of the material's sensible heat. Finally, by adjusting three-way valves 7 and 8, heat transfer fluid 2 is introduced into heat exchange tube 13 to extract heat, thereby reducing the enthalpy of the remaining 100℃, 1atm saturated steam-water (state point e) in the saturated steam-water energy storage device 2 until it returns to the initial saturated steam-water state (state point c) at 20℃ and 0.023atm, thus releasing heat energy through latent heat physical enthalpy change. The energy release process is thus complete. Throughout the process, the level gauge 12 monitors and ensures that a free liquid surface always exists within the saturated steam-water energy storage device 2, i.e., it remains in a steam-water two-phase state.

Claims

1. A thermochemical energy storage system coupled with vapor enthalpy enhancement, characterized in that, It includes a thermochemical energy storage device (1) and a saturated steam-water energy storage device (2) connected by pipelines. The thermochemical energy storage device (1) uses chemical enthalpy change and sensible thermal physical enthalpy change to store electrical energy and release it in the form of thermal energy; The saturated steam-water energy storage device (2) stores electrical energy and steam by means of latent heat physical enthalpy change and releases them in the form of heat energy and steam. The thermochemical energy storage device (1) and the saturated steam-water energy storage device (2) simultaneously store electrical energy and release thermal energy; Thermochemical energy storage device (1) and saturated steam-water energy storage device (2) construct a reversible thermochemical reaction relationship through steam; The thermochemical energy storage device (1) is equipped with a steam pipe, which is connected to a steam compressor (3). The steam compressor (3) is connected to the first port of a three-way valve (7) through a pipeline. The second port of the three-way valve (7) is connected to the outlet of the heat exchange tube (13) inside the saturated steam-water energy storage device (2). The third port is used to introduce the heat transfer fluid (2). The steam pipeline is equipped with an electric control valve (4), a three-way valve one (5), and a three-way valve two (6); the three-way valve one (5) leads a pipeline to the first port of the three-way valve four (8), the second port of the three-way valve four (8) is connected to the outlet of the heat exchange tube two (13) on the saturated steam-water energy storage device (2), and the third port is used to discharge the heat transfer fluid; The thermochemical energy storage device (1) includes a shell, and a CaO / Ca(OH)2 system thermochemical energy carrier packing (9), a heat exchange tube (10), and an electric heater (11) inside the shell. The CaO / Ca(OH)2 system thermochemical energy carrier filler (9) is an energy carrier particle made by freeze drying and granulation process, and its initial main component is Ca(OH)2. The heat exchange tube (10) and the electric heater (11) are both buried in the thermochemical energy carrier packing (9) of the CaO / Ca(OH)2 system. The heat exchange tube (10) and the electric heater (11) are connected to each other through metal fins to form a heat transfer network to enhance the internal heat transfer of the thermochemical energy storage device (1). The saturated steam-water energy storage device (2) includes a level gauge (12), a second heat exchange tube (13), saturated steam (14), and saturated water (15). The saturated steam-water energy storage device (2) has saturated water (15) at the bottom and saturated steam (14) at the top. The heat exchange tube (13) is located at the bottom of the saturated steam-water energy storage device (2). The level gauge (12) monitors the height of the saturated water (15) to ensure that the heat exchange tube (13) is always below the saturated water (15) level, so as to achieve sufficient heat exchange between the heat exchange tube (13) and the saturated water (15).

2. The thermochemical energy storage system coupled with vapor enthalpy enhancement according to claim 1, characterized in that, The electric control valve (4) is used to control the flow of product vapor of dehydration reaction and reactant vapor of hydration reaction by controlling the valve opening, as well as the pressure of thermochemical energy storage device (1) and saturated steam-water energy storage device (2). The three-way valve (5) is used to control the flow direction of the product vapor of the dehydration reaction and the reactant vapor of the hydration reaction; The three-way valve 2 (6) is used to control the steam inlet and outlet of the saturated steam-water energy storage device (2); The three-way valve three (7) and three-way valve four (8) are used to control the flow of the product vapor of the dehydration reaction during the energy storage process and the flow of the heat transfer fluid two in the heat exchange tube two (13) during the energy release process.

3. The operating method of a thermochemical energy storage system coupled with steam enthalpy enhancement as described in claim 1, characterized in that, This includes energy storage and energy release processes; The energy storage process takes place at a location where there is a power supply and where energy is stored. Includes the following steps: First, the electric heater (11) is turned on to heat the Ca(OH)2 thermochemical energy carrier packing (9) in the thermochemical energy storage device (1), so that the initial environmental state absorbs heat and the temperature rises, thereby storing electrical energy by means of sensible heat physical enthalpy change; when the temperature reaches the reaction conditions, the dehydration reaction occurs, absorbs chemical reaction enthalpy and generates CaO, thereby storing electrical energy by means of chemical reaction enthalpy change, while releasing superheated steam; Then, open the electric control valve (4), three-way valve one (5), three-way valve two (6), three-way valve three (7), and three-way valve four (8) to allow superheated steam to flow out of the thermochemical energy storage device (1), and flow through the electric control valve (4), three-way valve one (5), and three-way valve four (8) in sequence to enter the heat exchange tube two (13). The superheated steam exchanges heat and increases the enthalpy of the saturated water (15) in the saturated steam-water energy storage device (2) at ambient temperature through the heat exchange tube two (13). After the superheated steam flows out of the heat exchange tube two (13), it flows through the three-way valve three (7) to enter the steam compressor (3) for compression and enthalpy increase. Then it flows through the three-way valve two (6) to enter the saturated steam-water energy storage device (2) to mix with the saturated steam (14) and achieve a high enthalpy saturated steam-water state, realizing the equivalent storage of electrical energy by latent heat physical enthalpy change, while storing steam at the same time. Finally, the electric control valve (4) and the electric heater (11) are closed, and the energy storage process is completed. The energy release process takes place at a location where there is a demand for thermal energy. Includes the following steps: First, open the three-way valve one (5) and the three-way valve two (6), and control the opening of the electric control valve (4) so ​​that the saturated steam-water energy storage device (2) releases saturated steam from the original saturated steam-water state and enters the thermochemical energy storage device (1), which contacts the CaO thermochemical energy carrier packing (9) to drive the hydration reaction, generate Ca(OH)2 and release the chemical reaction enthalpy in the form of heat energy; at the same time, the heat transfer fluid one is introduced into the heat exchange tube one (10) to extract heat, so as to realize the release of heat energy by the change of chemical reaction enthalpy. By adjusting the flow rate of the heat transfer fluid one, the heat extraction power is controlled to obtain the heat transfer fluid one at different temperatures; Then, when the hydration reaction is complete, the heat transfer fluid continues to take heat through the heat exchange tube (10) until the temperature of the Ca(OH)2 thermochemical energy carrier packing (9) returns to its initial state, so as to release heat energy by means of the sensible enthalpy change of the material. Finally, open the three-way valve three (7) and the three-way valve four (8) to introduce the heat transfer fluid two into the heat exchange tube two (13) to extract heat, thereby reducing the enthalpy of the remaining saturated steam-water in the saturated steam-water energy storage device (2) until it returns to the initial saturated steam-water state, thus realizing the release of heat energy through latent heat physical enthalpy change. During this process, the flow rate of the heat transfer fluid two is adjusted by adjusting the opening of the three-way valve three (7) to control the heat extraction power, thereby obtaining the heat transfer fluid two at different temperatures; at this point, the energy release process is completed.

4. The operation method of a thermochemical energy storage system coupled with steam enthalpy enhancement according to claim 3, characterized in that, During the energy storage process, the level gauge (12) monitors and ensures that there is always a free liquid surface in the saturated steam-water energy storage device (2), that is, it is always in a steam-water two-phase state.

5. The operation method of a thermochemical energy storage system coupled with steam enthalpy enhancement according to claim 4, characterized in that, During the energy release process, the level gauge (12) monitors and ensures that there is always a free liquid surface in the saturated steam-water energy storage device (2), that is, it is always in a steam-water two-phase state.

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