Thermochemical energy storage system and method

Abstract

An outlet of a first regulating valve is communicated with an inlet of a gas storage tank through a fan and an electric heater in sequence, an outlet of the gas storage tank is communicated with an inlet of an evaporation section of a heat exchange tube in a thermochemical reactor, an outlet of the evaporation section of the heat exchange tube is divided into two paths, one path is communicated with an inlet of a steam pocket, and the other path is communicated with an outlet of the steam pocket. The outlet of the steam pocket is divided into two paths, one path is communicated with the inlet of the heat exchange tube overheating section, the other path is communicated with the shell side of the low-temperature waste heat recoverer, the outlet of the heat exchange tube overheating section is divided into two paths, one path is communicated with the eighth switch valve, and the other path is communicated with the shell side of the low-temperature waste heat recoverer. And the second path communicates with an inlet of the fan through the shell side of the high-temperature waste heat recoverer. The system and the method can improve the heat exchange efficiency of the thermochemical reactor.

Description

Technical Field

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

[0002] During the actual operation of a thermochemical reactor, we face a significant technical challenge, that is, the heat conduction ability of the material itself is relatively weak. This characteristic greatly limits the efficiency and flexibility of the thermochemical reactor in the heat storage and heat release processes. Traditionally, to address this problem, the thermochemical reactor mainly relies on electric heating rods to achieve heat input and accumulation during the heat storage stage. The electric heating rods convert electrical energy into heat energy to provide the necessary temperature conditions inside the reactor to meet the specific temperature requirements of the chemical reaction. However, during the heat release stage, the reactor instead uses heat exchange tubes to export the excess heat generated during the reaction process to prevent the reactor from overheating and maintain the stability of the reaction conditions.

[0003] But the problem is that this traditional heat storage and heat release method has obvious limitations. The electric heating rods and heat exchange tubes are functionally independent and cannot be used interchangeably. This means that during the heat storage process, the heat exchange tubes are often idle, and their heat exchange area cannot be effectively utilized; while during the heat release process, the electric heating rods also do not participate in the work, resulting in a waste of resources. This design not only leads to relatively limited heat exchange areas in both the heat storage and heat release processes and cannot be flexibly adjusted according to actual needs, but also further affects the overall thermal efficiency and energy utilization rate of the thermochemical reactor.

[0004] To overcome this technical bottleneck and improve the performance and efficiency of the thermochemical reactor, we need to explore more advanced and flexible thermal management technologies to optimize and coordinate the heat storage and heat release processes. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a thermochemical energy storage system and method that can improve the heat exchange efficiency of the thermochemical reactor.

[0006] To achieve the above purpose, the present invention discloses a thermochemical energy storage system, including a first regulating valve, a gas storage tank, a thermochemical reactor, a steam drum, a low-temperature waste heat recovery device, an eighth switching valve, and a feed water pump;

[0007] The outlet of the first regulating valve is successively connected to the inlet of the gas storage tank through a blower and an electric heater. The outlet of the gas storage tank is connected to the inlet of the evaporation section of the heat exchange tubes in the thermochemical reactor. The outlet of the evaporation section of the heat exchange tubes is divided into two paths. One path is connected to the inlet of the steam drum, and the other path is connected to the inlet of the superheat section of the heat exchange tubes in the thermochemical reactor. The outlet of the steam drum is divided into two paths. One path is connected to the inlet of the superheat section of the heat exchange tubes, and the other path is connected to the shell side of the low-temperature waste heat recovery device. The outlet of the superheat section of the heat exchange tubes is divided into two paths. One path is connected to the eighth switching valve, and the second path is connected to the inlet of the blower through the shell side of the high-temperature waste heat recovery device. The bottom outlet of the steam drum is divided into two paths after passing through a circulating water pump. One path is connected to the inlet of the steam drum through the shell sides of the low-temperature waste heat recovery device and the high-temperature waste heat recovery device, and the other path is connected to the inlet of the evaporation section of the heat exchange tubes through a pipe connection with the outlet of the feed water pump.

[0008] A further improvement of the thermochemical energy storage system of the present invention lies in:

[0009] Further, the outlet of the gas storage tank is connected to the inlet of the evaporation section of the heat exchange tubes in the thermochemical reactor through a second regulating valve.

[0010] Further, the outlet of the evaporation section of the heat exchange tubes is divided into two paths. One path is connected to the inlet of the steam drum through a sixth switching valve, and the other path is connected to the inlet of the superheat section of the heat exchange tubes in the thermochemical reactor through a first switching valve.

[0011] Further, the outlet of the steam drum is divided into two paths after passing through a third regulating valve. One path is connected to the inlet of the superheat section of the heat exchange tubes, and the other path is connected to the shell side of the low-temperature waste heat recovery device through a fourth regulating valve and a seventh switching valve.

[0012] Further, the outlet of the superheat section of the heat exchange tubes is divided into two paths. One path is connected to the eighth switching valve, and the second path is connected to the inlet of the blower through a second switching valve and the shell side of the high-temperature waste heat recovery device.

[0013] Further, the bottom outlet of the steam drum is divided into two paths after passing through a circulating water pump. One path is connected to the inlet of the steam drum through a fourth switching valve, the shell sides of the low-temperature waste heat recovery device and the high-temperature waste heat recovery device, and a third switching valve, and the other path is connected to the inlet of the evaporation section of the heat exchange tubes through a pipe connection with the outlet of the feed water pump through a fifth switching valve.

[0014] Further, a drain valve is connected to the inlet of the evaporation section of the heat exchange tubes, and the shell side outlet of the thermochemical reactor is connected to the shell side of the low-temperature waste heat recovery device through a seventh switching valve.

[0015] Further, the thermochemical reactor is a shell-and-tube type thermochemical reactor.

[0016] Further, the evaporation section of the heat exchange tubes adopts a vertical tube bundle; the superheat section of the heat exchange tubes adopts a serpentine tube bundle.

[0017] The present invention discloses a thermochemical energy storage method, comprising the following steps:

[0018] Heat storage process: Open the first regulating valve, start the fan and the electric heater. The high-temperature gas first enters the gas storage tank for pressure boosting. When the pressure is greater than the set value P1, open the second regulating valve and the first switching valve, close the third regulating valve, the eighth switching valve and the drain valve. The high-temperature gas enters the evaporation section and the superheat section of the heat exchange tubes to release heat. The gas after heat release enters the high-temperature waste heat recovery device for heat recovery, and then returns to the fan inlet for circulation; The hot air heats the material in the thermochemical reactor to decompose and generate steam. Open the seventh switching valve, and the steam enters the low-temperature waste heat recovery device to be cooled and discharged. The water in the steam drum passes through the circulating water pump and the fourth switching valve, and then enters the low-temperature waste heat recovery device and the high-temperature waste heat recovery device in sequence. The generated steam enters the steam drum through the third switching valve 11 for storage;

[0019] Heat release process: Start the circulating water pump, and the circulating water enters the evaporation section of the heat exchange tubes. The generated water vapor enters the steam drum. When the pressure P1 of the steam drum is greater than the set value, open the third regulating valve, and the steam enters the superheat section of the heat exchange tubes. Open the eighth switching valve and close the second switching valve to supply the superheated steam externally. When the temperature of the material in the thermochemical reactor is less than the set value Ta, open the fourth regulating valve, and part of the saturated steam enters the thermochemical reactor to react with the internal material. When the temperature of the material in the thermochemical reactor is lower than the set value Tc, or the steam generated by the thermochemical reactor cannot meet the user's demand, the heat release stops.

[0020] The present invention has the following beneficial effects:

[0021] When the thermochemical energy storage system and method of the present invention are specifically operated, in the heat storage stage, the high-temperature gas first enters the gas storage tank for pressure boosting, and then enters the evaporation section and the superheat section of the heat exchange tubes to release heat; in the heat release process, start the circulating water pump, and the circulating water enters the evaporation section of the heat exchange tubes. The generated water vapor enters the steam drum, that is, the high-temperature gas flows through the heat exchange tubes during the heat storage process, and water flows through during the heat release process, which greatly increases the heat exchange area of the overall reactor and further improves the heat exchange power. Description of the Drawings

[0022] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0023] Figure 1 is the structural diagram of the present invention.

[0024] Among them, 1 is the first regulating valve, 2 is the fan, 3 is the electric heater, 4 is the gas storage tank, 5 is the second regulating valve, 6 is the thermal chemical reactor, 6.1 is the evaporation section of the heat exchange tube, 6.2 is the superheat section of the heat exchange tube, 7 is the first switching valve, 8 is the second switching valve, 9 is the high-temperature waste heat recovery device, 10 is the low-temperature waste heat recovery device, 11 is the third switching valve, 12 is the steam drum, 13 is the circulating water pump, 14 is the fourth switching valve, 15 is the fifth switching valve, 16 is the sixth switching valve, 17 is the third regulating valve, 18 is the fourth regulating valve, 19 is the seventh switching valve, 20 is the eighth switching valve, 21 is the feed water pump, and 22 is the drain valve. Specific embodiments

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] In the description of the present invention, it should be understood that the terms "include" and "comprise" indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations.

[0027] It should also be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0028] It should be further understood that the term " / and / or" used in the specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations. For example, A and / or B may represent: the presence of A alone, the presence of both A and B, and the presence of B alone. In addition, the character " / " in the present invention generally represents an "or" relationship between the front and rear associated objects.

[0029] It should be understood that although the terms first, second, third, etc. may be used in the embodiments of the present invention to describe preset ranges, etc., these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0030] Depending on the context, as used herein, the word "if" can be interpreted as "when" or "while" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if determined" or "if detected (stated condition or event)" can be interpreted as "when determined" or "in response to determining" or "when detected (stated condition or event)" or "in response to detecting (stated condition or event)".

[0031] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Components in the embodiments of the present invention as generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations. Thus, the detailed description of the embodiments of the present invention provided herein is not intended to limit the scope of the claimed invention, but is merely representative of selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0032] Structural schematic diagrams according to the disclosed embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes and relative positions according to actual requirements.

[0033] As is well known, a thermal chemical reactor is a device for implementing a specific chemical reaction process. It uses thermal energy to drive chemical reactions and is widely used in multiple fields such as chemical engineering, energy, and environmental protection. The following is a detailed introduction to the thermal chemical reactor: The thermal chemical reactor provides the necessary heat and reaction environment to cause the raw materials to undergo chemical reactions under certain conditions to produce the desired products. Its principle generally involves the transfer and utilization of thermal energy to accelerate or promote the progress of chemical reactions.

[0034] The main types include batch reactors, tubular reactors, tower reactors, fixed-bed reactors and fluidized-bed reactors. Among them, batch reactor: Structure: It is mainly composed of a stirrer, a tank body, a jacket, a discharge pipe, a manhole, a shaft seal, a transmission device and a support, etc. Application: Widely used in organic chemical production and fine chemical production, suitable for homogeneous reactions such as esterification reaction and saponification reaction, as well as multiphase reactions such as liquid-phase, liquid-liquid phase, liquid-solid phase, gas-liquid-solid phase, etc. Characteristics: Wide applicable temperature and pressure ranges, strong adaptability and large operating flexibility. Tubular reactor: Structure: It is divided into single-tube and multi-tube types, and the multi-tube type has two forms: multi-tube parallel connection and multi-tube series connection. Application: More used in continuous reactions, such as cracking of petroleum hydrocarbons to produce ethylene and propylene, synthesis of vinyl chloride, synthesis of ethylene oxide, etc. Characteristics: Less backmixing, and when the flow rate is low, the flow pattern of the fluid in the tube is close to that of an ideal fluid.

[0035] Example 1

[0036] Reference Figure 1 , the thermochemical energy storage system of the present invention includes a first regulating valve 1, a fan 2, an electric heater 3, a gas storage tank 4, a second regulating valve 5, a thermochemical reactor 6, an evaporation section 6.1 of the heat exchange tube, a superheat section 6.2 of the heat exchange tube, a first switching valve 7, a second switching valve 8, a high-temperature waste heat recovery device 9, a low-temperature waste heat recovery device 10, a third switching valve 11, a steam drum 12, a circulating water pump 13, a fourth switching valve 14, a fifth switching valve 15, a sixth switching valve 16, a third regulating valve 17, a fourth regulating valve 18, a seventh switching valve 19, an eighth switching valve 20, a feed water pump 21 and a drain valve 22;

[0037] The outlet of the first regulating valve 1 is successively connected to the inlet of the gas storage tank 4 through the blower 2 and the electric heater 3. The outlet of the gas storage tank 4 is connected to the inlet of the evaporation section 6.1 of the heat exchange tubes in the thermochemical reactor 6 through the second regulating valve 5. The outlet of the evaporation section 6.1 of the heat exchange tubes is divided into two paths. One path is connected to the inlet of the steam drum 12 through the sixth switching valve 16, and the other path is connected to the inlet of the superheat section 6.2 of the heat exchange tubes in the thermochemical reactor 6 through the first switching valve 7. The outlet of the steam drum 12 is divided into two paths after passing through the third regulating valve 17. One path is connected to the inlet of the superheat section 6.2 of the heat exchange tubes, and the other path is connected to the shell side of the low-temperature waste heat recovery device 10 through the fourth regulating valve 18 and the seventh switching valve 19. The outlet of the superheat section 6.2 of the heat exchange tubes is divided into two paths. One path is connected to the eighth switching valve 20, and the second path is connected to the inlet of the blower 2 through the second switching valve 8 and the shell side of the high-temperature waste heat recovery device 9. The bottom outlet of the steam drum 12 is divided into two paths after passing through the circulation water pump 13. One path is connected to the inlet of the steam drum 12 through the fourth switching valve 14, the shell side of the low-temperature waste heat recovery device 10, the shell side of the high-temperature waste heat recovery device 9, and the third switching valve 11. The other path is connected to the outlet of the feed water pump 21 through the fifth switching valve 15 and is combined with the inlet of the evaporation section 6.1 of the heat exchange tubes through a pipe. A drain valve 22 is connected to the inlet of the evaporation section 6.1 of the heat exchange tubes. The shell side outlet of the thermochemical reactor 6 is connected to the shell side of the low-temperature waste heat recovery device 10 through the seventh switching valve 19.

[0038] Embodiment 2

[0039] This embodiment discloses a thermochemical energy storage method, which is realized based on the thermochemical energy storage system. The thermochemical energy storage system includes a first regulating valve 1, a blower 2, an electric heater 3, a gas storage tank 4, a second regulating valve 5, a thermochemical reactor 6, an evaporation section 6.1 of the heat exchange tubes, a superheat section 6.2 of the heat exchange tubes, a first switching valve 7, a second switching valve 8, a high-temperature waste heat recovery device 9, a low-temperature waste heat recovery device 10, a third switching valve 11, a steam drum 12, a circulation water pump 13, a fourth switching valve 14, a fifth switching valve 15, a sixth switching valve 16, a third regulating valve 17, a fourth regulating valve 18, a seventh switching valve 19, an eighth switching valve 20, a feed water pump 21, and a drain valve 22. The connection relationship is as shown in Embodiment 1.

[0040] Specifically, the thermochemical energy storage method includes the following steps:

[0041] Heat storage process: Open the first regulating valve 1, start the fan 2 and the electric heater 3. The high-temperature gas first enters the gas storage tank 4 for pressure boosting. When the pressure is greater than the set value P1, open the second regulating valve 5 and the first on-off valve 7, close the third regulating valve 17, the eighth on-off valve 20 and the drain valve 22. The high-temperature gas enters the evaporation section 6.1 and the superheat section 6.2 of the heat exchange tube to release heat. The gas after heat release enters the high-temperature waste heat recovery device 9 for heat recovery, and then returns to the inlet of the fan 2 for circulation. The hot air heats the material in the thermochemical reactor 6 to decompose and generate steam. Open the seventh on-off valve 19. The steam enters the low-temperature waste heat recovery device 10 to be cooled and then discharged. The water in the steam drum 12 passes through the circulating water pump 13 and the fourth on-off valve 14, and then enters the low-temperature waste heat recovery device 10 and the high-temperature waste heat recovery device 9 in sequence. The generated steam enters the steam drum 12 through the third on-off valve 11 for storage.

[0042] During the heat storage process, the second regulating valve 5 is used to control the pressure of the gas storage tank 4 and the air intake into the thermochemical reactor 6. Set the material temperature in the thermochemical reactor 6 as T1. When T1 is greater than the set value Ta, it is considered that the heat storage is completed. At this time, the heat storage capacity Q of the system = a1m1ΔT1 + m1h + a2m2,1ΔT2 + a2m2,2r, where a1 is the specific heat of the material in the thermochemical reactor 6, m1 is the mass of the material in the thermochemical reactor 6, h is the chemical heat of the material, a2 is the specific heat of the hot water in the steam drum 12, m2,1 is the mass of the hot water in the steam drum 12, T2 is the temperature of the hot water in the steam drum 12, m2,2 is the mass of the steam in the steam drum 12, and r is the latent heat of vaporization of water.

[0043] The heat release process is as follows: Start the circulating water pump 13. The circulating water enters the evaporation section 6.1 of the heat exchange tube. The generated water vapor enters the steam drum 12. When the pressure P1 of the steam drum 12 is greater than the set value, open the third regulating valve 17. The steam enters the superheat section 6.2 of the heat exchange tube. Open the eighth on-off valve 20 and close the second on-off valve 8 to supply the superheated steam externally. When the material temperature in the thermochemical reactor 6 is less than the set value Ta, open the fourth regulating valve 18. Part of the saturated steam enters the thermochemical reactor 6 to react with the internal material. The opening degree of the fourth regulating valve 18 is inversely proportional to the material temperature rising rate, that is, a3 / k1 = dT1 / dt, where a3 is the proportionality coefficient and k1 is the opening degree of the fourth regulating valve 18. When the material temperature in the thermochemical reactor 6 is lower than the set value Tc, or the steam generated by the thermochemical reactor 6 cannot meet the user's demand, the heat release stops.

[0044] During the heat release process, the water level of the steam drum 12 is adjusted by the feed water pump 21. When the water level of the steam drum 12 is lower than the set value, start the feed water pump 21 to supplement the water level in the steam drum 12 to normal.

[0045] After the exothermic process ends, to avoid water remaining in the evaporation section 6.1 of the heat exchange tubes and causing heat exchange with hot air during the heat storage process, the drain valve 22 is opened to drain the water in the evaporation section 6.1 of the heat exchange tubes.

[0046] The present invention designs a partitioned heat chemical reactor 6. High-temperature gas flows through the heat exchange tubes during the heat storage process, and water flows through them during the exothermic process, greatly increasing the heat exchange area of the overall reactor and further improving the heat exchange power. The present invention adds a high-temperature waste heat recovery device 9 and a low-temperature waste heat recovery device 10, increasing the energy utilization rate to over 90%. In addition, the heat chemical reactor 6 in the present invention is vertically arranged, and the internal heat exchange tubes are divided into two sections. One section is the evaporation section 6.1 of the heat exchange tubes, which uses a vertical tube bundle, and the other section is the superheat section 6.2 of the heat exchange tubes, which uses a serpentine tube bundle. This can ensure that the thermal stress in the heat chemical reactor 6 is relatively uniform and prevent equipment damage due to thermal stress problems.

[0047] Those skilled in the art will readily conceive of other embodiments of the present invention upon considering the specification and the disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include known common knowledge or conventional technical means in the technical field not disclosed by the present invention. The specification and the embodiments are only regarded as exemplary, and the true scope and spirit of the present invention are pointed out by the following claims.

[0048] It should be understood that the present invention is not limited to the precise structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

[0049] The above description is only a preferred embodiment of the present invention and does not impose any limitation on the present invention. Any simple modifications, changes, and equivalent structural changes made to the above embodiments based on the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A thermochemical energy storage system, characterized in that, It includes a first regulating valve (1), a gas storage tank (4), a thermal chemical reactor (6), a steam drum (12), a low-temperature waste heat recovery device (10), an eighth switching valve (20), and a feed water pump (21); The outlet of the first regulating valve (1) is successively connected to the inlet of the gas storage tank (4) through a blower (2) and an electric heater (3). The outlet of the gas storage tank (4) is connected to the inlet of the evaporation section (6.1) of the heat exchange tubes in the thermal chemical reactor (6). The outlet of the evaporation section (6.1) of the heat exchange tubes is divided into two paths. One path is connected to the inlet of the steam drum (12), and the other path is connected to the inlet of the superheat section (6.2) of the heat exchange tubes in the thermal chemical reactor (6). The outlet of the steam drum (12) is divided into two paths. One path is connected to the inlet of the superheat section (6.2) of the heat exchange tubes, and the other path is connected to the shell side of the low-temperature waste heat recovery device (10). The outlet of the superheat section (6.2) of the heat exchange tubes is divided into two paths. One path is connected to the eighth switching valve (20), and the second path is connected to the inlet of the blower (2) through the shell side of the high-temperature waste heat recovery device (9). The bottom outlet of the steam drum (12) is divided into two paths after passing through a circulating water pump (13). One path is connected to the inlet of the steam drum (12) through the shell side of the low-temperature waste heat recovery device (10) and the shell side of the high-temperature waste heat recovery device (9), and the other path is connected to the inlet of the evaporation section (6.1) of the heat exchange tubes through a pipe connection with the outlet of the feed water pump (21).

2. The thermochemical energy storage system according to claim 1, wherein The outlet of the gas storage tank (4) is connected to the inlet of the evaporation section (6.1) of the heat exchange tubes in the thermal chemical reactor (6) through a second regulating valve (5).

3. The thermochemical energy storage system according to claim 2, characterized in that, The outlet of the evaporation section (6.1) of the heat exchange tubes is divided into two paths. One path is connected to the inlet of the steam drum (12) through a sixth switching valve (16), and the other path is connected to the inlet of the superheat section (6.2) of the heat exchange tubes in the thermal chemical reactor (6) through a first switching valve (7).

4. The thermochemical energy storage system according to claim 3, characterized in that, The outlet of the steam drum (12) is divided into two paths after passing through a third regulating valve (17). One path is connected to the inlet of the superheat section (6.2) of the heat exchange tubes, and the other path is connected to the shell side of the low-temperature waste heat recovery device (10) through a fourth regulating valve (18) and a seventh switching valve (19).

5. The thermochemical energy storage system according to claim 4, characterized in that The outlet of the superheat section (6.2) of the heat exchange tubes is divided into two paths. One path is connected to the eighth switching valve (20), and the second path is connected to the inlet of the blower (2) through the shell side of the high-temperature waste heat recovery device (9) and a second switching valve (8).

6. The thermochemical energy storage system according to claim 5, characterized in that, The bottom outlet of the steam drum (12) is divided into two paths after passing through a circulating water pump (13). One path is connected to the inlet of the steam drum (12) through a fourth switching valve (14), the shell side of the low-temperature waste heat recovery device (10), the shell side of the high-temperature waste heat recovery device (9), and a third switching valve (11), and the other path is connected to the inlet of the evaporation section (6.1) of the heat exchange tubes through a pipe connection with the outlet of the feed water pump (21) through a fifth switching valve (15).

7. The thermochemical energy storage system according to claim 6, wherein, A drain valve (22) is connected to the inlet of the evaporation section (6.1) of the heat exchange tubes. The shell side outlet of the thermal chemical reactor (6) is connected to the shell side of the low-temperature waste heat recovery device (10) through a seventh switching valve (19).

8. The thermochemical energy storage system according to claim 1, characterized in that, The thermal chemical reactor (6) is a shell-and-tube type thermal chemical reactor.

9. The thermochemical energy storage system according to claim 1, characterized in that The evaporation section (6.1) of the heat exchange tube adopts a vertical tube bundle; the superheat section (6.2) of the heat exchange tube adopts a serpentine tube bundle.

10. A thermochemical energy storage method, characterized in that, The thermochemical energy storage system according to claim 7 includes the following steps: Heat storage process: Open the first regulating valve (1), start the fan (2) and the electric heater (3). The high-temperature gas first enters the gas storage tank (4) for pressure boosting. When the pressure is greater than the set value P1, open the second regulating valve (5) and the first switching valve (7), close the third regulating valve (17), the eighth switching valve (20) and the drain valve (22). The high-temperature gas enters the evaporation section (6.1) and the superheat section (6.2) of the heat exchange tube to release heat. The gas after heat release enters the high-temperature waste heat recovery device (9) for heat recovery, and then returns to the inlet of the fan (2) for circulation. The hot air heats the material in the thermochemical reactor (6) to decompose and generate steam. Open the seventh switching valve (19), and the steam enters the low-temperature waste heat recovery device (10) to be cooled and then discharged. The water in the steam drum (12) passes through the circulating water pump (13) and the fourth switching valve (14), and then enters the low-temperature waste heat recovery device (10) and the high-temperature waste heat recovery device (9) in sequence. The generated steam enters the steam drum (12) through the third switching valve (11) for storage. Heat release process: Start the circulating water pump (13), the circulating water enters the evaporation section (6.1) of the heat exchange tube, and the generated water vapor enters the steam drum (12). When the pressure P1 of the steam drum (12) is greater than the set value, open the third regulating valve (17), the steam enters the superheat section (6.2) of the heat exchange tube, open the eighth switching valve (20), close the second switching valve (8), and supply the superheated steam externally. When the temperature of the material in the thermochemical reactor (6) is less than the set value Ta, open the fourth regulating valve (18), and part of the saturated steam enters the thermochemical reactor (6) to react with the internal material. When the temperature of the material in the thermochemical reactor (6) is lower than the set value Tc, or the steam generated by the thermochemical reactor (6) cannot meet the user's demand, the heat release stops.

Images