A system and method for utilizing waste heat thermochemical storage coupled with oxy-combustion in a thermal power plant

Abstract

The application relates to the technical field of energy storage, and discloses a thermal-chemical storage coupling oxygen-enriched combustion utilization system and method for waste heat of a thermal power plant, wherein a heat energy output end of high-temperature flue gas or steam bypass of the thermal power plant is connected to a heat energy input end of a thermal-chemical energy storage and release reaction unit, necessary heat energy is provided for an energy storage reactor, heat carried by flue gas of the thermal power plant and heat carried by steam which is easily wasted during low-load operation are fully utilized, the utilization efficiency of heat energy of the thermal power plant is improved, energy waste is reduced or avoided, the thermal-chemical energy storage and release reaction unit and an energy storage reaction material storage container are sequentially and circularly connected to form a loop, a thermal-chemical reaction product can be simply regenerated through an oxidation reaction, heat is released and recycled, and the waste heat of the thermal power plant is effectively stored and utilized, energy consumption is reduced, and energy is saved.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, specifically to a system and method for the thermochemical storage of waste heat from thermal power plants coupled with oxygen-enriched combustion utilization. Background Technology

[0002] Thermal power plants often generate waste heat that is not fully utilized for power generation. This waste heat can be recovered and utilized through various technologies, such as using low-temperature economizers to recover waste heat from flue gas to heat boiler feedwater, thereby improving energy conversion efficiency and reducing energy waste. However, significant energy losses still occur during combustion flue gas emissions and water circulation. The combustion of fossil fuels also produces substantial carbon dioxide emissions, making energy conservation, emission reduction, and emission reduction the primary goals that thermal power plants urgently need to achieve. On the other hand, oxy-fuel combustion technology uses pure oxygen or oxygen-enriched air as the combustion-supporting gas, enabling more complete fuel combustion. This not only improves combustion efficiency and heat utilization but also helps reduce pollutant emissions and improve the efficiency of subsequent carbon capture. These characteristics make oxy-fuel combustion technology of significant environmental and economic value in thermal power plants, but it also increases the operating costs of thermal power plants due to the need to provide a high concentration of oxygen.

[0003] Thermochemical energy storage technology stores and releases energy through reversible chemical reactions, representing a novel and efficient energy storage method. It converts thermal energy into the chemical energy of storage materials, offering higher energy density than sensible and latent heat storage, and enabling long-term energy storage, long-distance transportation, and reuse. However, thermochemical energy storage typically requires the reversible decomposition and synthesis of storage materials such as carbonates, hydroxides, metal hydrides, and metal oxides. This endothermic decomposition process generates a large amount of gaseous products, increasing the difficulty and cost of storing these products. Furthermore, current thermochemical energy storage technology is primarily applied to concentrated solar energy storage and concentrated solar power (CSP), and the intermittent nature of solar energy presents challenges to the start-up and shutdown processes of thermochemical energy storage systems. Summary of the Invention

[0004] In order to overcome the defects of the prior art, the present invention aims to provide a thermal power plant waste heat thermochemical storage coupled with oxygen-enriched combustion utilization system and method, so as to solve the technical problem of how to improve the storage and efficient utilization of waste heat in thermal power plants in the prior art.

[0005] This invention is achieved through the following technical solution:

[0006] In a first aspect, the present invention provides a waste heat thermochemical storage coupled with oxygen-enriched combustion utilization system for thermal power plants, comprising a high-temperature flue gas or steam bypass of the thermal power plant, a thermochemical energy storage and release reaction unit, an energy storage reaction material storage container, and an oxygen-enriched combustion system; the heat energy output end of the high-temperature flue gas or steam bypass of the thermal power plant is connected to the heat energy input end of the thermochemical energy storage and release reaction unit, the material output end of the thermochemical energy storage and release reaction unit is connected to the input end of the energy storage reaction material storage container, and the output end of the energy storage reaction material storage container is connected to the material input end of the thermochemical energy storage and release reaction unit, forming a circulation loop; the oxygen output end of the thermochemical energy storage and release reaction unit is connected to the oxygen-enriched combustion system.

[0007] Preferably, the thermochemical energy storage and release reaction unit includes an energy storage reactor, an energy release reactor, and a solid oxygen storage unit;

[0008] The thermal energy input end of the energy storage reactor is connected to the high-temperature flue gas or steam bypass of the thermal power plant; the solid-gas output end of the energy storage reactor is connected to the solid oxygen storage unit; the solid product output end of the solid oxygen storage unit is connected to the input end of the energy release reactor; the material output end of the energy release reactor is connected to the energy storage reaction material storage container; and the gaseous product output end of the solid oxygen storage unit is connected to the oxygen-enriched combustion system.

[0009] Preferably, the solid oxygen storage unit includes a solid product storage container and an oxygen storage tank;

[0010] The solid product output end of the energy storage reactor is connected to the input end of the solid product storage container; the output end of the solid product storage container is connected to the input end of the energy release reactor.

[0011] The gas product output end of the energy storage reactor is connected to the input end of the oxygen storage tank; the output end of the oxygen storage tank is connected to the input end of the energy release reactor.

[0012] Furthermore, the energy release reactor is equipped with a gas inlet for introducing air or oxygen.

[0013] Secondly, the present invention also provides a method for utilizing waste heat from thermal power plants through thermochemical storage coupled with oxygen-enriched combustion, based on the aforementioned system for utilizing waste heat from thermal power plants through thermochemical storage coupled with oxygen-enriched combustion, comprising the following processes:

[0014] High-temperature flue gas or steam bypass from a thermal power plant provides heat energy to an energy storage reactor. Within the reactor, the energy storage material undergoes an endothermic chemical reaction, and the solid products from this reaction are transported to a solid product storage container. Simultaneously, oxygen is transported to an oxygen storage tank. The solid product storage container then transports the solid products to an energy release reactor, where an exothermic reverse reaction occurs. The products from this exothermic reverse reaction are transported to an energy storage material storage container to provide energy storage material for the reactor. Oxygen from the oxygen storage tank is supplied to the oxygen-enriched combustion system to provide oxygen for the system.

[0015] Furthermore, the energy storage material within the energy storage reactor utilizes M... x O (y+2z) Thermal energy is supplied to the energy storage reactor through a bypass of high-temperature flue gas or steam from a thermal power plant. The energy storage material within the reactor undergoes an endothermic chemical reaction, the specific reaction formula of which is as follows:

[0016] M x O (y+2z) +△H→M x O y +zO2

[0017] Among them, M x O y O2 is a solid product of the energy storage chemical reaction; O2 is a gaseous product of the energy storage chemical reaction.

[0018] Furthermore, energy storage material M x O (y+2z) M is a metallic material, which includes one of Ba, Co, Mn, Cu, Fe and Zn.

[0019] Furthermore, the solid products of the endothermic chemical reaction undergo an exothermic reverse reaction in the energy-releasing reactor, as detailed in the following reaction formula:

[0020] M x O y +zO2→M x O (y+2z) +△H;

[0021] Among them, M x O (y+2z) It is an energy storage material.

[0022] Furthermore, in the exothermic reverse reaction of the endothermic chemical reaction, the solid products of the endothermic chemical reaction are introduced into the exothermic reactor as reactants for the reverse reaction, with air as the heat energy medium.

[0023] Furthermore, the oxygen from the oxygen storage tank is delivered to the oxygen-enriched combustion system, which uses pure oxygen or oxygen-enriched air as the combustion-supporting gas. The combustion forms include micro-oxygen-enriched combustion, pure oxygen combustion, or air-oxygen combustion.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] This invention provides a waste heat thermochemical storage coupled with oxygen-enriched combustion utilization system for thermal power plants. The heat energy output end of the high-temperature flue gas or steam bypass of the thermal power plant is connected to the heat energy input end of the thermochemical energy storage and release reaction unit, providing the necessary heat energy for the energy storage reactor. At the same time, it makes full use of the heat carried by the flue gas of the thermal power plant and the heat carried by the steam that is easily wasted during low-load operation, thereby improving the utilization efficiency of thermal energy in the thermal power plant and reducing or avoiding energy waste. The thermochemical energy storage and release reaction unit and the energy storage reaction material storage container are sequentially and cyclically connected to form a loop. The energy storage chemical reaction products can be easily regenerated and recycled by releasing heat through oxidation reaction, effectively realizing the storage and efficient utilization of waste heat in thermal power plants and energy saving and consumption reduction. At the same time, the oxygen output end of the thermochemical energy storage and release reaction unit is connected to the oxygen-enriched combustion system to realize the continuous storage of waste heat in thermal power plants and the reduction of pollutant emissions, ensuring the stable operation of thermal power plants during low-load periods.

[0026] Furthermore, the thermochemical energy storage and release reaction unit includes an energy storage reactor, an energy release reactor, and a solid oxygen storage unit; the thermal energy input end of the energy storage reactor is connected to the high-temperature flue gas or steam bypass of the thermal power plant; the solid-gas output end of the energy storage reactor is connected to the solid oxygen storage unit, the solid product output end of the solid oxygen storage unit is connected to the input end of the energy release reactor, and the material output end of the energy release reactor is connected to the energy storage reaction material storage container; the gaseous product output end of the solid oxygen storage unit is connected to the oxygen-enriched combustion system; the energy storage reactor uses flue gas or steam from the high-temperature flue gas bypass or steam bypass of the thermal power plant as fuel. The heat medium fluid can stably supply the required heat for the energy storage reaction. The energy storage reactor stores solid and gaseous products separately through a solid oxygen storage unit and then transports them to the energy release reactor and the oxygen-enriched combustion system. The solid products are produced in the energy release reactor to obtain energy storage materials, which greatly improves the recycling of energy storage materials. The oxygen-enriched combustion system uses pure oxygen or oxygen-enriched air as combustion gas, which can reduce the theoretical air volume for fuel combustion in thermal power plant boilers, accelerate the fuel combustion rate, increase the theoretical flame temperature, and reduce flue gas emissions, thereby reducing pollutant and carbon dioxide emissions.

[0027] This invention also provides a method for the thermochemical storage and oxygen-enriched combustion utilization of waste heat from thermal power plants. The method involves an endothermic chemical reaction occurring in the energy storage material within an energy storage reactor, with the solid products from this reaction being transported to a solid product storage container, while the oxygen products are simultaneously transported to an oxygen storage tank. The solid product storage container then transports the solid products to an energy release reactor, where an exothermic reverse reaction occurs. The products of this exothermic reverse reaction are transported to an energy storage material storage container to provide energy storage material for the energy storage reactor. Oxygen from the oxygen storage tank is then supplied to the oxygen-enriched combustion system. This method enables continuous storage of waste heat from thermal power plants, ensuring stable operation during low-load periods. It also replaces the air separation unit, providing oxygen to the oxygen-enriched combustion system. The products from the energy storage chemical reaction can be easily regenerated through oxidation, releasing heat for recovery and utilization. This achieves the goals of waste heat storage and efficient utilization, energy conservation, emission reduction, and pollutant reduction from thermal power plants. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of a thermal power plant waste heat thermochemical storage coupled with oxygen-enriched combustion utilization system in an embodiment of the present invention.

[0029] In the diagram: 1-High-temperature flue gas or steam bypass in a thermal power plant; 2-Energy storage reactor; 3-Solid product storage container; 4-Energy release reactor; 5-Energy storage material storage container; 6-Oxygen storage tank; 7-Oxygen-enriched combustion system; Detailed Implementation

[0030] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0032] The present invention will now be described in further detail with reference to the accompanying drawings:

[0033] The purpose of this invention is to provide a system and method for thermochemical storage coupled with oxygen-enriched combustion of waste heat from thermal power plants, so as to solve the technical problem of how to improve the storage and efficient utilization of waste heat from thermal power plants in the prior art.

[0034] Example 1

[0035] See Figure 1 In one embodiment of the present invention, a waste heat thermochemical storage coupled with oxygen-enriched combustion utilization system for thermal power plants is provided, comprising a high-temperature flue gas or steam bypass 1, a thermochemical energy storage and release reaction unit, an energy storage reaction material storage container 5, and an oxygen-enriched combustion system 7; the heat energy output end of the high-temperature flue gas or steam bypass 1 is connected to the heat energy input end of the thermochemical energy storage and release reaction unit, the material output end of the thermochemical energy storage and release reaction unit is connected to the input end of the energy storage reaction material storage container 5, and the output end of the energy storage reaction material storage container 5 is connected to the material input end of the thermochemical energy storage and release reaction unit, forming a circulation loop; the oxygen output end of the thermochemical energy storage and release reaction unit is connected to the oxygen-enriched combustion system 7.

[0036] Specifically, the thermochemical energy storage and release reaction unit includes energy storage reactor 2, energy release reactor 4, and solid oxygen storage unit;

[0037] The thermal energy input end of the energy storage reactor 2 is connected to the high-temperature flue gas or steam bypass 1 of the thermal power plant; the solid-gas output end of the energy storage reactor 2 is connected to the solid oxygen storage unit; the solid product output end of the solid oxygen storage unit is connected to the input end of the energy release reactor 4; the material output end of the energy release reactor 4 is connected to the energy storage reaction material storage container 5; and the gaseous product output end of the solid oxygen storage unit is connected to the oxygen-enriched combustion system 7.

[0038] Specifically, the solid oxygen storage unit includes a solid product storage container 3 and an oxygen storage tank 6;

[0039] The solid product output end of the energy storage reactor 2 is connected to the input end of the solid product storage container 3; the output end of the solid product storage container 3 is connected to the input end of the energy release reactor 4.

[0040] The gas product output end of the energy storage reactor 2 is connected to the input end of the oxygen storage tank 6; the output end of the oxygen storage tank 6 is connected to the input end of the energy release reactor 4.

[0041] The energy release reactor 4 is equipped with a gas inlet for introducing air or oxygen.

[0042] In this embodiment, the high-temperature flue gas or steam bypass 1 of the thermal power plant refers to a bypass that draws a portion of high-temperature flue gas from the boiler's turning chamber, or a bypass that draws a portion of high-temperature, high-pressure steam from between the boiler and the turbine. It mainly consists of bypass valves, bypass pipes, warm-up facilities, and corresponding control systems. Its primary function is to provide the necessary thermal energy to the energy storage reactor, while fully utilizing the heat carried by the flue gas and the heat carried by the steam that is easily wasted during low-load operation, thereby improving the thermal energy utilization efficiency of the thermal power plant and reducing or avoiding energy waste. The type and facilities of this bypass are selected and designed according to the reaction temperature requirements of the energy storage reactor 2.

[0043] In this embodiment, the energy storage reactor 2 is the site where the endothermic chemical reaction occurs. It uses flue gas or steam from the high-temperature flue gas or steam bypass 1 of the thermal power plant as the heating medium, ensuring a stable supply of the required heat for the energy storage reaction. The energy storage reactor can be a fixed-bed reactor, a fluidized-bed reactor, or a moving-bed reactor, etc.

[0044] In this embodiment, the solid product storage container 3 refers to a container that can stably store solid products of endothermic chemical reactions. It is required to be able to adapt to the storage conditions of the reaction products and to be easily transported to the location where they are needed before being connected to the energy release reactor 4.

[0045] In this embodiment, the energy release reactor 4 is the site where the exothermic reverse reaction of the energy storage endothermic chemical reaction occurs and the energy storage material is regenerated. The energy storage material generated by the exothermic reverse reaction is transported to the energy storage reaction material storage container 5 for storage.

[0046] In this embodiment, the energy storage reactor material storage container 5 refers to a container that can stably store energy storage materials. It is required to be able to adapt to the storage conditions of energy storage materials and to be easily transported and connected to the energy storage reactor 2.

[0047] In this embodiment, the oxygen storage tank 6 is a container that can stably store the gaseous product O2 of an energy-absorbing and heat-absorbing chemical reaction, and supply oxygen to the oxygen-enriched combustion system 7 of a thermal power plant.

[0048] In this embodiment, the oxygen-enriched combustion system 7 is a boiler combustion technology system in a thermal power plant that utilizes pure oxygen or oxygen-enriched air as the combustion-supporting gas. It can take the form of micro-oxygen-enriched combustion, oxygen injection lance, pure oxygen combustion, air-oxygen combustion, etc., and uses oxygen supplied from the oxygen storage tank 6 as the oxygen source, eliminating the need for an air separation unit. This system can reduce the theoretical air volume required for fuel combustion in thermal power plant boilers, accelerate fuel combustion speed, increase theoretical flame temperature, and reduce flue gas emissions, thereby reducing pollutant and carbon dioxide emissions.

[0049] In summary, this invention provides a waste heat thermochemical storage coupled with oxygen-enriched combustion utilization system for thermal power plants. The heat energy output end of the high-temperature flue gas or steam bypass of the thermal power plant is connected to the heat energy input end of the thermochemical energy storage and release reaction unit, providing the necessary heat energy for the energy storage reactor. At the same time, it makes full use of the heat carried by the flue gas of the thermal power plant and the heat carried by the steam that is easily wasted during low-load operation, thereby improving the utilization efficiency of thermal energy in the thermal power plant and reducing or avoiding energy waste. The thermochemical energy storage and release reaction unit and the energy storage reaction material storage container are sequentially and cyclically connected to form a loop. The energy storage chemical reaction products can be easily regenerated through oxidation reaction and the heat released can be recovered and utilized, effectively realizing the storage and efficient utilization of waste heat in thermal power plants, energy saving and consumption reduction. At the same time, the oxygen output end of the thermochemical energy storage and release reaction unit is connected to the oxygen-enriched combustion system to realize the continuous storage of waste heat in thermal power plants and the reduction of pollutant emissions, ensuring the stable operation of thermal power plants during low-load periods.

[0050] Example 2

[0051] This embodiment 2 provides a method for utilizing waste heat from thermal power plants through thermochemical storage coupled with oxygen-enriched combustion. Based on the aforementioned system for utilizing waste heat from thermal power plants through thermochemical storage coupled with oxygen-enriched combustion, the method includes the following process:

[0052] The high-temperature flue gas or steam bypass 1 of the thermal power plant provides thermal energy to the energy storage reactor 2. The energy storage material in the energy storage reactor 2 undergoes an endothermic chemical reaction, and the solid products produced by the endothermic chemical reaction are transported to the solid product storage container 3. At the same time, the oxygen product is transported to the oxygen storage tank 6. The solid product storage container 3 transports the solid product to the energy release reactor 4, where an exothermic reverse reaction of the endothermic chemical reaction occurs. The products of the exothermic reverse reaction of the endothermic chemical reaction are transported to the energy storage material storage container 5, which is used to provide energy storage material for the energy storage reactor 2. The oxygen in the oxygen storage tank 6 is transported to the oxygen-enriched combustion system 7, which is used to provide oxygen for the oxygen-enriched combustion system 7.

[0053] Specifically, the energy storage material in energy storage reactor 2 adopts M x O (y+2z) Thermal energy is supplied to the energy storage reactor 2 through the high-temperature flue gas or steam bypass 1 of the thermal power plant. The energy storage material in the energy storage reactor 2 undergoes an endothermic chemical reaction, and the specific reaction formula is as follows:

[0054] M x O (y+2z) +△H→M x O y +zO2

[0055] Among them, M x O y O2 is a solid product of the energy storage chemical reaction; O2 is a gaseous product of the energy storage chemical reaction.

[0056] Among them, energy storage material M x O (y+2z) M is a metallic material, and M includes one of Ba, Co, Mn, Cu, Fe, and Zn. For example, M is composed of a single metal. x O (y+2z) / M x O y The substance pairs include BaO2 / BaO, Co3O4 / CoO, Mn2O3 / Mn3O4, CuO / Cu2O, Fe2O3 / Fe3O4, ZnO / Zn, etc.

[0057] Specifically, the solid products of the endothermic chemical reaction undergo an exothermic reverse reaction in the energy-releasing reactor 4. The specific reaction formula is as follows:

[0058] M x O y +zO2→M x O (y+2z) +△H;

[0059] Among them, M x O (y+2z) It is an energy storage material.

[0060] In this embodiment, the solid product of the energy storage endothermic chemical reaction undergoes an exothermic reverse reaction in the energy release reactor 4. By introducing air or pure oxygen into the energy release reactor 4 as the reactant of the reverse reaction, the air also serves as the heat energy medium.

[0061] In this embodiment, oxygen from oxygen storage tank 6 is delivered to oxygen-enriched combustion system 7. Oxygen-enriched combustion system 7 uses pure oxygen or oxygen-enriched air as combustion-supporting gas, and the combustion forms include micro-oxygen-enriched combustion, pure oxygen combustion, or air-oxygen combustion.

[0062] In summary, this embodiment provides a method for the thermochemical storage and oxygen-enriched combustion utilization of waste heat from thermal power plants. An endothermic chemical reaction occurs within the energy storage reactor, and the solid products from this reaction are transported to a solid product storage container, while the oxygen products are transported to an oxygen storage tank. The solid product storage container transports the solid products to an energy release reactor, where an exothermic reverse reaction occurs. The products of this exothermic reverse reaction are then transported to an energy storage material storage container to provide energy storage material for the reactor. Oxygen from the oxygen storage tank is supplied to the oxygen-enriched combustion system. This method enables continuous storage of waste heat from thermal power plants, ensuring stable operation during low-load periods. It also replaces the air separation unit, providing oxygen to the oxygen-enriched combustion system. The products from the energy storage chemical reaction can be easily regenerated through oxidation and the released heat can be recovered and utilized, achieving the goals of waste heat storage and efficient utilization, energy conservation and emission reduction.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A waste heat thermochemical storage coupled with oxygen-enriched combustion utilization system for thermal power plants, characterized in that, It includes a high-temperature flue gas or steam bypass (1) of a thermal power plant, a thermochemical energy storage and release reaction unit, an energy storage reaction material storage container (5), and an oxygen-enriched combustion system (7); the heat output end of the high-temperature flue gas or steam bypass (1) of the thermal power plant is connected to the heat input end of the thermochemical energy storage and release reaction unit, the material output end of the thermochemical energy storage and release reaction unit is connected to the input end of the energy storage reaction material storage container (5), and the output end of the energy storage reaction material storage container (5) is connected to the material input end of the thermochemical energy storage and release reaction unit, forming a circulation loop; the oxygen output end of the thermochemical energy storage and release reaction unit is connected to the oxygen-enriched combustion system (7). The thermochemical energy storage and release reaction unit includes an energy storage reactor (2), an energy release reactor (4), and a solid oxygen storage unit; The thermal energy input end of the energy storage reactor (2) is connected to the high-temperature flue gas or steam bypass (1) of the thermal power plant; the solid gas output end of the energy storage reactor (2) is connected to the solid oxygen storage unit, the solid product output end of the solid oxygen storage unit is connected to the input end of the energy release reactor (4), the material output end of the energy release reactor (4) is connected to the energy storage reaction material storage container (5); the gas product output end of the solid oxygen storage unit is connected to the oxygen-enriched combustion system (7).

2. The waste heat thermochemical storage coupled with oxygen-enriched combustion utilization system of a thermal power plant according to claim 1, characterized in that, The solid oxygen storage unit includes a solid product storage container (3) and an oxygen storage tank (6). The solid product output end of the energy storage reactor (2) is connected to the input end of the solid product storage container (3); the output end of the solid product storage container (3) is connected to the input end of the energy release reactor (4). The gas product output end of the energy storage reactor (2) is connected to the input end of the oxygen storage tank (6); the output end of the oxygen storage tank (6) is connected to the input end of the energy release reactor (4).

3. The waste heat thermochemical storage coupled with oxygen-enriched combustion utilization system of a thermal power plant according to claim 1, characterized in that, The energy release reactor (4) is equipped with a gas inlet for inputting air or oxygen.

4. A method for utilizing waste heat from thermal power plants through thermochemical storage coupled with oxygen-enriched combustion, characterized in that, A waste heat thermochemical storage coupled with oxygen-enriched combustion utilization system for thermal power plants according to any one of claims 1-3 includes the following process: The high-temperature flue gas or steam bypass (1) of the thermal power plant provides heat energy to the energy storage reactor (2). The energy storage material in the energy storage reactor (2) undergoes an endothermic chemical reaction, and the solid products produced by the endothermic chemical reaction are transported to the solid product storage container (3). At the same time, the oxygen products are transported to the oxygen storage tank (6). The solid product storage container (3) transports the solid products to the energy release reactor (4), where the endothermic chemical reaction of the energy storage reactor (4) undergoes an exothermic reverse reaction, and the products of the exothermic reverse reaction of the endothermic chemical reaction are transported to the energy storage reaction material storage container (5) to provide energy storage material to the energy storage reactor (2). The oxygen in the oxygen storage tank (6) is transported to the oxygen-enriched combustion system (7) to provide oxygen to the oxygen-enriched combustion system (7).

5. A method for utilizing waste heat from thermal power plants via thermochemical storage coupled with oxygen-enriched combustion according to claim 4, characterized in that, The energy storage material in the energy storage reactor (2) is M x O (y+2z) Thermal energy is supplied to the energy storage reactor (2) through the high-temperature flue gas or steam bypass (1) of the thermal power plant. The energy storage material in the energy storage reactor (2) undergoes an endothermic chemical reaction. The specific reaction formula is as follows: M x THE (y+2z) +△H→M x THE y +zO2 Among them, M x O y O2 is a solid product of the energy storage chemical reaction; O2 is a gaseous product of the energy storage chemical reaction.

6. The method for utilizing waste heat from thermal power plants through thermochemical storage coupled with oxygen-enriched combustion according to claim 5, characterized in that, The energy storage material M x O (y+2z) M is a metallic material, which includes one of Ba, Co, Mn, Cu, Fe and Zn.

7. A method for utilizing waste heat from thermal power plants via thermochemical storage coupled with oxygen-enriched combustion according to claim 5, characterized in that, The solid products of the endothermic chemical reaction undergo an exothermic reverse reaction in the energy-releasing reactor (4). The specific reaction formula is as follows: M x O y +zO2→M x O (y+2z) +△H; Among them, M x O (y+2z) It is an energy storage material.

8. A method for utilizing waste heat from thermal power plants through thermochemical storage coupled with oxygen-enriched combustion according to claim 7, characterized in that, In the exothermic reverse reaction of the endothermic chemical reaction of the stored energy product, air or pure oxygen is introduced into the exothermic reactor (4) as the reactant of the reverse reaction, and air is used as the heat energy medium.

9. A method for utilizing waste heat from thermal power plants via thermochemical storage coupled with oxygen-enriched combustion according to claim 7, characterized in that, The oxygen in the oxygen storage tank (6) is delivered to the oxygen-enriched combustion system (7). The oxygen-enriched combustion system (7) uses pure oxygen or oxygen-enriched air as the combustion-supporting gas. The combustion forms include micro-oxygen-enriched combustion, pure oxygen combustion, or air-oxygen combustion.

Images