Power generation system and method based on thermochemical energy storage

Abstract

The invention discloses a power generation system and method based on thermochemical energy storage, an outlet of a water storage tank is divided into two paths after passing through a first water pump, the first path is communicated with a pipe side inlet of a thermochemical reactor, and the second path is communicated with a shell side inlet of the thermochemical reactor through a first electric heater; a shell side outlet of the thermochemical reactor is communicated with an inlet of the ejector, a pipe side outlet of the thermochemical reactor is communicated with an inlet of the steam turbine, an outlet of the ejector is communicated with the inlet of the steam turbine, an outlet of the steam turbine is divided into two paths, one path is communicated with an inlet of the water storage tank, and the other path is communicated with an outlet of the steam turbine. The other path is communicated with a shell side inlet of the thermochemical reactor, and an outlet of the water storage tank is communicated with an inlet of the ejector through a second electric heater; an electric heating device is arranged in the shell side of the thermochemical reactor, a power interface of the electric heating device is connected with the green electricity, the system and the method can absorb surplus electric energy generated by the green electricity, and an electricity utilization gap can be compensated when the green electricity is insufficient.

Description

Technical Field

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

[0002] Green electricity refers to electricity generated from specific renewable energy sources with zero or near-zero carbon dioxide emissions during its production. The main sources of green electricity include solar, wind, biomass, geothermal, and other renewable energy sources. In China, solar and wind power are the primary components of green electricity. While green electricity offers significant advantages such as environmental friendliness and sustainability, it also suffers from disadvantages such as intermittency and instability. Consequently, how to absorb surplus electricity generated by green electricity and fill electricity shortages when it is insufficient poses a significant challenge to its development and application. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a power generation system and method based on thermochemical energy storage, which can absorb the surplus electric energy generated by green electricity and compensate for the electricity gap when green electricity is insufficient.

[0004] To achieve the above-mentioned object, the present invention discloses a power generation system based on thermochemical energy storage, comprising a water storage tank, a first water pump, a thermochemical reactor, a first electric heater, an ejector, a steam turbine and a second electric heater;

[0005] The outlet of the water storage tank is divided into two paths after passing through the first water pump, wherein the first path is connected to the tube-side inlet of the thermochemical reactor, and the second path is connected to the shell-side inlet of the thermochemical reactor through the first electric heater. The shell-side outlet of the thermochemical reactor is connected to the inlet of the ejector, the tube-side outlet of the thermochemical reactor is connected to the inlet of the steam turbine, and the outlet of the ejector is connected to the inlet of the steam turbine. The outlet of the steam turbine is divided into two paths, one of which is connected to the inlet of the water storage tank and the other is connected to the shell-side inlet of the thermochemical reactor. The outlet of the water storage tank is connected to the inlet of the ejector through the second electric heater.

[0006] An electric heating device is provided inside the shell side of the thermochemical reactor, the output shaft of the steam turbine is connected to a generator, the output end of the generator is connected to the external power grid, and the power interface of the electric heating device is connected to green electricity.

[0007] Furthermore, the outlet of the first water pump is connected to the inlet of the first electric heater via a regulating valve.

[0008] Furthermore, the outlet of the first water pump is connected to the tube-side inlet of the thermochemical reactor via a first switching valve.

[0009] Furthermore, the tube-side outlet of the thermochemical reactor is connected to the inlet of the steam turbine via a second switching valve.

[0010] Furthermore, the outlet of the steam turbine is connected to the inlet of the water storage tank via a third switch valve.

[0011] Furthermore, the outlet of the steam turbine is connected to the shell-side inlet of the thermochemical reactor via a fourth switching valve.

[0012] Furthermore, the outlet of the ejector is connected to the inlet of the steam turbine via a fifth switch valve.

[0013] Furthermore, the reaction medium in the thermochemical reactor is a calcium hydroxide / calcium oxide or magnesium hydroxide / magnesium oxide system.

[0014] Furthermore, heat storage material is arranged on the outer side of the tube in the thermochemical reactor.

[0015] The present invention discloses a method for power generation based on thermochemical energy storage, comprising the following steps:

[0016] During the heat storage process, the electric heating device in the thermochemical reactor is activated. The electric heating device uses the surplus electric energy of green electricity to decompose the heat storage material to generate water vapor. The second water pump is activated to heat the feed water output from the water storage tank through the second electric heater to form steam. The steam in the thermochemical reactor is then ejected through the ejector to form mixed steam. The mixed steam enters the steam turbine through the fourth switch valve to perform work. The exhaust steam of the steam turbine returns to the water storage tank through the third switch valve.

[0017] During the heat release process, when green electricity is insufficient, the first water pump is started, the first switch valve is opened, and the feed water is heated in the tube side of the thermochemical reactor to become steam, and then enters the steam turbine. The exhaust steam of the steam turbine enters the shell side of the thermochemical reactor through the fourth switch valve to react with the heat storage material to release heat.

[0018] The present invention has the following beneficial effects:

[0019] During specific operation of the power generation system and method based on thermochemical energy storage described in the present invention, when there is surplus green electricity, the electric heating device uses the surplus green electricity to decompose the heat storage material to achieve electric energy storage. At the same time, when green electricity is insufficient, the heat storage material is used to generate heat to generate steam, which is then sent to the steam turbine to generate electricity to compensate for the green electricity gap. The operation is simple and the practicality is extremely strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 It is a structural diagram of the present invention.

[0022] Among them, 1 is a water storage tank, 2 is the first water pump, 3 is the first switch valve, 4 is the regulating valve, 5 is the first electric heater, 6 is the thermochemical reactor, 7 is the second switch valve, 8 is the steam turbine, 9 is the third switch valve, 10 is the fourth switch valve, 11 is the fifth switch valve, 12 is the ejector, 13 is the second electric heater, and 14 is the second water pump. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0024] In the description of the present invention, it is to 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 collections thereof.

[0025] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0026] It should be further understood that the term "and / or" as used in the present specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.

[0027] It should be understood that although the terms "first," "second," and "third" may be used to describe preset ranges in embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are merely used to distinguish one preset range from another. For example, without departing from the scope of 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.

[0028] The word "if," as used herein, may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to the determination" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)," depending on the context.

[0029] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0031] As is known to all, a thermochemical reactor is a device that realizes a specific chemical reaction process. It uses heat energy to drive chemical reactions and is widely used in many fields such as chemical industry, energy, and environmental protection. The following is a detailed introduction to thermochemical reactors:

[0032] A thermochemical reactor provides the necessary heat and reaction environment to enable raw materials to undergo a chemical reaction under certain conditions to produce the desired product. The principle generally involves the transfer and utilization of thermal energy to accelerate or promote the chemical reaction.

[0033] Main types

[0034] Tank Reactor: Structure: Primarily composed of an agitator, tank, jacket, extrusion pipe, manhole, shaft seal, transmission device, and support. Application: Widely used in organic and fine chemical production, suitable for homogeneous reactions such as esterification and saponification, as well as multiphase reactions such as liquid-phase, liquid-liquid, liquid-solid, and gas-liquid-solid. Features: Wide applicable temperature and pressure range, strong adaptability, and high operational flexibility.

[0035] Tubular Reactors: Structure: Available in single-tube and multi-tube configurations. Multi-tube reactors can be connected in parallel or in series. Applications: Mostly used in continuous reactions, such as petroleum hydrocarbon cracking to produce ethylene and propylene, vinyl chloride synthesis, and ethylene oxide synthesis. Features: Minimal backmixing. At low flow rates, the flow pattern within the tubes approaches that of an ideal flow.

[0036] Tower Reactors: Common structures include plate towers, packed towers, spray towers, and bubble towers. Applications: In addition to being widely used in distillation, absorption, desorption, and extraction, they can also be used as reactors for gas-liquid reactions. Features: Plate and packed towers are primarily used in processes where two fluids react. Spray towers disperse liquid into a gas in the form of droplets, while bubble towers allow gas to react as bubbles through a liquid layer.

[0037] Fixed-Bed Reactor: Structure: The reactor is filled with stationary solid catalyst particles or solid reactants. Application: Primarily used for gas-solid phase catalytic reactions, such as ammonia synthesis towers, sulfur dioxide contact oxidizers, and hydrocarbon steam reformers. Features: Simple structure, minimal auxiliary equipment required, and easy operation.

[0038] Fluidized Bed Reactor: Principle: Utilizes gas or liquid passing through a granular solid layer to suspend the solid particles, allowing for gas-solid or liquid-solid phase reactions. Applications: Widely used in the chemical, petroleum, metallurgical, and nuclear industries. Features: Excellent heat transfer, uniform and easily controllable temperature within the bed, and suitable for highly exothermic reactions.

[0039] Example 1

[0040] refer to Figure 1 The power generation system based on thermochemical energy storage of the present invention comprises a water storage tank 1, a first water pump 2, a thermochemical reactor 6, a first electric heater 5, an ejector 12, a steam turbine 8 and a second electric heater 13;

[0041] The outlet of the water storage tank 1 is divided into two paths after passing through the first water pump 2, wherein the first path is connected to the tube side inlet of the thermochemical reactor 6, and the second path is connected to the shell side inlet of the thermochemical reactor 6 through the first electric heater 5, the shell side outlet of the thermochemical reactor 6 is connected to the inlet of the ejector 12, the tube side outlet of the thermochemical reactor 6 is connected to the inlet of the steam turbine 8, the outlet of the ejector 12 is connected to the inlet of the steam turbine 8, and the outlet of the steam turbine 8 is divided into two paths, one of which is connected to the inlet of the water storage tank 1, and the other is connected to the shell side inlet of the thermochemical reactor 6, the outlet of the water storage tank 1 is connected to the inlet of the ejector 12 through the second electric heater 13; an electric heating device is provided in the shell side of the thermochemical reactor 6, the output shaft of the steam turbine 8 is connected to a generator, the output end of the generator is connected to the external power grid, and the power interface of the electric heating device is connected to the green power.

[0042] Example 2

[0043] refer to Figure 1 To improve this application, the power generation system based on thermochemical energy storage described in the present invention includes a water storage tank 1, a first water pump 2, a first switch valve 3, a regulating valve 4, a first electric heater 5, a thermochemical reactor 6, a second switch valve 7, a steam turbine 8, a third switch valve 9, a fourth switch valve 10, a fifth switch valve 11, an ejector 12, a second electric heater 13 and a second water pump 14;

[0044] The outlet of the water storage tank 1 is divided into two paths after passing through the first water pump 2, wherein the first path is connected to the tube side inlet of the thermochemical reactor 6, and the second path is connected to the shell side inlet of the thermochemical reactor 6 through the first electric heater 5, the shell side outlet of the thermochemical reactor 6 is connected to the inlet of the ejector 12, the tube side outlet of the thermochemical reactor 6 is connected to the inlet of the steam turbine 8, the outlet of the ejector 12 is connected to the inlet of the steam turbine 8, the outlet of the steam turbine 8 is divided into two paths, one of which is connected to the inlet of the water storage tank 1, and the other is connected to the shell side inlet of the thermochemical reactor 6, the outlet of the water storage tank 1 is connected to the inlet of the ejector 12 through the second electric heater 13.

[0045] As an embodiment of the present invention, the outlet of the first water pump 2 is connected to the pipe-side inlet of the thermochemical reactor 6 via the first switching valve 3 .

[0046] As an embodiment of the present invention, the outlet of the first water pump 2 is connected to the inlet of the first electric heater 5 via the regulating valve 4 .

[0047] As an embodiment of the present invention, the tube-side outlet of the thermochemical reactor 6 is connected to the inlet of the steam turbine 8 via the second switching valve 7 .

[0048] As an embodiment of the present invention, the outlet of the ejector 12 is connected to the inlet of the steam turbine 8 via the fifth switching valve 11.

[0049] As an embodiment of the present invention, the outlet of the steam turbine 8 is connected to the inlet of the water storage tank 1 via the third switch valve 9 .

[0050] As an embodiment of the present invention, the outlet of the steam turbine 8 is connected to the shell-side inlet of the thermochemical reactor 6 via the fourth switching valve 10 .

[0051] As an embodiment of the present invention, the reaction medium in the thermochemical reactor 6 is a calcium hydroxide / calcium oxide or magnesium hydroxide / magnesium oxide system; an electric heating device is provided in the thermochemical reactor 6, and a heat storage material is arranged on the outside of the tube side of the thermochemical reactor 6, and the electric heating device is connected to the green electricity.

[0052] As an embodiment of the present invention, this embodiment also includes a controller, which is connected to the first water pump 2, the first switch valve 3, the regulating valve 4, the first electric heater 5, the second switch valve 7, the third switch valve 9, the fourth switch valve 10, the fifth switch valve 11, the second electric heater 13 and the second water pump 14, and controls the first water pump 2, the first switch valve 3, the regulating valve 4, the first electric heater 5, the second switch valve 7, the third switch valve 9, the fourth switch valve 10, the fifth switch valve 11, the second electric heater 13 and the second water pump 14 through the controller.

[0053] Example 3

[0054] refer to Figure 1 The present invention discloses a method for power generation based on thermochemical energy storage. The method for power generation based on thermochemical energy storage is implemented based on the power generation system based on thermochemical energy storage. The power generation system based on thermochemical energy storage includes a water storage tank 1, a first water pump 2, a first switch valve 3, a regulating valve 4, a first electric heater 5, a thermochemical reactor 6, a second switch valve 7, a steam turbine 8, a third switch valve 9, a fourth switch valve 10, a fifth switch valve 11, an ejector 12, a second electric heater 13 and a second water pump 14. The specific connection relationship is shown in Example 2.

[0055] Specifically, the power generation method based on thermochemical energy storage includes the following steps:

[0056] During the heat storage process, the electric heating device in the thermochemical reactor 6 is started to decompose the heat storage medium and generate water vapor. The second water pump 14 is started to heat the feed water output from the water storage tank 1 into steam through the second electric heater 13. The steam in the thermochemical reactor 6 is then ejected through the ejector 12 to form mixed steam. The mixed steam enters the steam turbine 8 to perform work. The exhaust steam of the steam turbine 8 returns to the water storage tank 1 through the third switch valve 9. The power of the second water pump 14 is set to Pw. The size of Pw is related to the steam temperature Ta at the heat release outlet of the ejector 8. The steam saturation temperature at the outlet pressure of the ejector 12 is Tb. Then Pw = a*(1 / (T a / Tb)), where a is the proportional coefficient; the power of the second electric heater 13 is related to the inlet steam temperature of the turbine 8. The enthalpy of the steam released from the thermochemical reactor 6 is set to hr, the flow rate is Dr, the inlet steam enthalpy of the turbine 8 is set to hd, and the feed water flow leaving the second feed water pump 14 is Dw. Then the heating power Pc of the second electric heater 13 is Pc=(Dw+Dr)hd-Pw-Drhr; during the heat storage process, the relationship between the work P1 of the turbine 8 and the electric power P2 of the thermochemical reactor 6 and the electric power P2 of the second electric heater 13 is: P1=b1(b2P2+P2), where b1 and b2 are proportional coefficients.

[0057] The output shaft of the steam turbine 8 is connected to the drive shaft of the generator, and the power interface of the second electric heater 13 and the power interface of the second water pump 14 are connected to the green power.

[0058] During the heat release process, the electric heating device in the thermochemical reactor 6 is turned off, the first water pump 2 is started, and the first switch valve 3 is opened. The feed water is heated in the tube side of the thermochemical reactor 6 to become steam, and then enters the steam turbine 8. The exhaust steam of the steam turbine 8 enters the shell side of the thermochemical reactor 6 through the fourth switch valve 10 to react with the heat storage medium to release heat. The exhaust steam of the steam turbine 8 enters the thermochemical reactor 6 through the fourth switch valve 10 to react with the heat storage medium to release heat. The opening degree of the fourth switch valve 10 is related to the material temperature T1 and the temperature change rate dT1 in the thermochemical reactor 6. When T1 is less than the set value T1a When dT1 is less than 0, the fourth switch valve 10 is closed. When the temperature of the steam entering the steam turbine 8 does not reach the set value, the second water pump 14 and the second electric heater 13 are started to supplement part of the high-temperature steam and the thermochemical reactor 6. The outlet steam is mixed and enters the steam turbine 8. The material temperature in the thermochemical reactor 6 is set to T, and the exhaust steam of the steam turbine 8 enters the water storage tank 1.

[0059] During the heat release start-up process, before the turbine 8 is started, the first electric heater 5 is started, the regulating valve 4 is opened, and the first electric heater 5 heats part of the feed water into steam which then enters the thermochemical reactor 6, causing the thermochemical reactor 6 to start releasing heat.

[0060] The output end of the generator is connected to the power interface of the second water pump 2, the power interface of the first electric heater 5 and the external power grid.

[0061] The present invention has the following characteristics:

[0062] 1) The present invention is a battery based on thermochemical energy storage, which can realize low-cost consumption of green electricity and achieve source-load matching.

[0063] 2) The present invention utilizes thermochemical energy storage to improve the quality and efficiency of the exhaust steam at the outlet of the steam turbine 8, achieving a heat pump effect with a COP>1.2.

[0064] 3) The present invention is a closed cycle and can be processed into a mobile power supply vehicle in a skid-mounted form.

[0065] Those skilled in the art will readily identify other embodiments of the present invention after considering the specification and 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 invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

[0066] It should be understood that the present invention is not limited to the exact construction described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

[0067] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A power generation system based on thermochemical energy storage, characterized in that: It comprises a water storage tank (1), a first water pump (2), a thermochemical reactor (6), a first electric heater (5), an ejector (12), a steam turbine (8) and a second electric heater (13); The outlet of the water storage tank (1) is divided into two paths after passing through the first water pump (2), wherein the first path is connected to the tube side inlet of the thermochemical reactor (6), and the second path is connected to the shell side inlet of the thermochemical reactor (6) through the first electric heater (5). The shell side outlet of the thermochemical reactor (6) is connected to the inlet of the ejector (12). The tube side outlet of the thermochemical reactor (6) is connected to the inlet of the steam turbine (8). The outlet of the ejector (12) is connected to the inlet of the steam turbine (8). The outlet of the steam turbine (8) is divided into two paths, wherein one path is connected to the inlet of the water storage tank (1) and the other path is connected to the shell side inlet of the thermochemical reactor (6). The outlet of the water storage tank (1) is connected to the inlet of the ejector (12) through the second electric heater (13). An electric heating device is provided inside the shell side of the thermochemical reactor (6); the output shaft of the steam turbine (8) is connected to a generator; the output end of the generator is connected to an external power grid; and the power supply interface of the electric heating device is connected to green electricity.

2. The power generation system based on thermochemical energy storage according to claim 1, characterized in that: The outlet of the first water pump (2) is connected to the inlet of the first electric heater (5) via a regulating valve (4).

3. The power generation system based on thermochemical energy storage according to claim 2, characterized in that: The outlet of the first water pump (2) is connected to the pipe-side inlet of the thermochemical reactor (6) via a first switching valve (3).

4. The power generation system based on thermochemical energy storage according to claim 3, characterized in that: The tube-side outlet of the thermochemical reactor (6) is connected to the inlet of the steam turbine (8) via the second switching valve (7).

5. The power generation system based on thermochemical energy storage according to claim 4, characterized in that: The outlet of the steam turbine (8) is connected to the inlet of the water storage tank (1) via the third switch valve (9).

6. The power generation system based on thermochemical energy storage according to claim 5, characterized in that: The outlet of the steam turbine (8) is connected to the shell side inlet of the thermochemical reactor (6) via a fourth switching valve (10).

7. The power generation system based on thermochemical energy storage according to claim 6, characterized in that: The outlet of the ejector (12) is connected to the inlet of the steam turbine (8) via the fifth switch valve (11).

8. The power generation system based on thermochemical energy storage according to claim 1, characterized in that: The reaction medium in the thermochemical reactor (6) is a calcium hydroxide / calcium oxide or magnesium hydroxide / magnesium oxide system.

9. The power generation system based on thermochemical energy storage according to claim 1, characterized in that: Heat storage material is arranged on the outer side of the tube side of the thermochemical reactor (6).

10. A method for power generation based on thermochemical energy storage, characterized in that: The power generation system based on thermochemical energy storage according to claim 7 comprises the following steps: During the heat storage process, the electric heating device in the thermochemical reactor (6) is started. The electric heating device uses the surplus electric energy of green electricity to decompose the heat storage material to generate water vapor. The second water pump (14) is started to heat the feed water output from the water storage tank (1) through the second electric heater (13) to become steam. The steam in the thermochemical reactor (6) is then ejected through the ejector (12) to form mixed steam. The mixed steam enters the steam turbine (8) through the fourth switch valve (10) to perform work. The exhaust steam of the steam turbine (8) returns to the water storage tank (1) through the third switch valve (9). During the heat release process, when green electricity is insufficient, the first water pump (2) is started, the first switch valve (3) is opened, and the feed water is heated in the tube side of the thermochemical reactor (6) to become steam, and then enters the steam turbine (8). The exhaust steam of the steam turbine (8) enters the shell side of the thermochemical reactor (6) through the fourth switch valve (10) to react with the heat storage material to release heat.

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