Thermochemical heat-accumulation energy-storage heat supply system, and energy-storage heat supply method

Abstract

Provided in the present invention are a thermochemical heat-accumulation energy-storage heat supply system, and an energy-storage heat supply method. The heat supply system comprises a first steam buffer tank and a thermochemical heat accumulation device, wherein the thermochemical heat accumulation device comprises a decomposition reactor, a first bin, a synthesis reactor and a second bin, which are in communication in sequence from end to end; the thermochemical heat accumulation device is internally provided with a calcium-based material capable of being circularly conveyed, the decomposition reactor being provided with an energy supply device, and a circulation pipe of the first steam buffer tank being in communication with the synthesis reactor; and an inlet of the first steam buffer tank is in communication with the decomposition reactor by means of a first steam pipeline, and the inlet of the first steam buffer tank is in communication with the synthesis reactor by means of a second steam pipeline. By means of the present invention, the use of a conventional boiler is avoided, such that chemical heat-accumulation energy storage and heat supply can be carried out in a valley electricity period, heat supply can be carried out only by means of chemical heat release in a peak electricity period, and thus peak clipping and valley filling of electrical energy can be effectively carried out, thereby eliminating the problem of carbon emission of a conventional heat supply system, and facilitating a reduction in the electricity consumption cost.

Description

Thermochemical thermal energy storage and heating system and energy storage heating method

[0001] This application claims priority to Chinese Patent Application No. 2022230893674, filed on November 22, 2022, and Chinese Patent Application No. 2022114411901, filed on November 22, 2022. The full text of the aforementioned Chinese patent applications is incorporated herein by reference. Technical Field

[0002] This invention relates to the field of chemical energy storage technology, and in particular to a thermochemical thermal energy storage and heating system and method. Background Technology

[0003] In existing technologies, heat storage technologies are mainly divided into three types: sensible heat storage, latent heat storage, and chemical heat storage. Sensible heat storage has low heat density, significant heat loss, and a short storage period; phase change heat storage suffers from problems such as phase separation, material leakage, and corrosion. Compared to the first two technologies, thermochemical energy storage has significant advantages such as high energy density, high reaction temperature, and low long-term heat loss, and can effectively solve the problems of electrical energy conversion, storage, transmission, and high-temperature regeneration. However, current research on chemical energy storage is mostly limited to micro / small-scale experimental studies focusing on the characteristics of energy storage materials, with few complete closed-loop systems developed, and large-scale industrial applications have not yet been achieved.

[0004] Currently, the national power supply is relatively tight, mainly due to the severe shortage during peak hours, while the supply is more abundant during off-peak hours. Generally, the peak load of the power grid is 50% to 100% higher than the off-peak load, and the peak electricity price is also higher than the off-peak price. Therefore, energy storage technology is being promoted in many industrial and residential sectors. This involves storing energy during off-peak hours and utilizing this stored energy during peak hours to reduce power supply pressure and electricity costs during peak periods.

[0005] Taking the light industry sector as an example, such as food processing enterprises, a certain amount of heat is often required during their production process to meet production needs. Currently, many enterprises use conventional heating systems such as coal-fired boilers or electric boilers for heating, which often presents problems such as environmental protection and difficulties in peak-valley electricity regulation.

[0006] Therefore, given the current relatively tight energy and electricity supply, it is necessary to improve the existing conventional heating systems in both industrial and residential sectors.

[0007] Summary of the Invention

[0008] In view of this, the present invention aims to propose a thermochemical thermal energy storage heating system and energy storage heating method, which improves the conventional heating system in the prior art. By using thermochemical thermal energy storage to peak and valley filling of electrical energy, the electrical energy is optimized and used effectively, so as to solve the problems of high carbon emissions, difficulty in peak and valley electricity regulation, and high electricity costs of conventional heating systems.

[0009] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0010] A thermochemical thermal energy storage and heating system includes a first steam buffer tank and a thermochemical thermal storage device. The thermochemical thermal storage device includes a decomposition reactor, a first silo, a synthesis reactor, and a second silo connected sequentially. The thermochemical thermal storage device contains calcium-based materials that can be circulated and transported. The decomposition reactor is equipped with an energy supply device. The circulation pipe of the first steam buffer tank is connected to the synthesis reactor, enabling the transfer of a portion of the steam in the first steam buffer tank to the synthesis reactor. The inlet of the first steam buffer tank is connected to the decomposition reactor via a first steam pipeline for collecting superheated steam produced in the decomposition reactor. The inlet of the first steam buffer tank is also connected to the synthesis reactor via a second steam pipeline for collecting superheated steam produced in the synthesis reactor, or the steam produced in the synthesis reactor can be vented through the second steam pipeline.

[0011] Furthermore, the first steam buffer tank has a steam supply pipeline, and the first steam buffer tank is connected to the steam consumption system through the steam supply pipeline.

[0012] Furthermore, the heating system includes a water supply unit, which includes a water supply source, a softened water tank, a heat exchanger, and a water storage tank connected in sequence. The softened water tank is provided with a first water pipe, which is connected to the low-temperature medium flow channel of the heat exchanger, and the first steam pipe is connected to the high-temperature medium flow channel of the heat exchanger.

[0013] Furthermore, the synthesis reactor is equipped with a heat exchange device, the outlet of the water storage tank is connected to the inlet of the heat exchange device, and the outlet of the heat exchange device is connected to the first steam buffer tank.

[0014] Furthermore, a steam ejector is installed at the outlet of the second steam pipeline or heat exchanger, and the outlet of the second steam pipeline or heat exchanger is connected to the inlet of the steam ejector. The outlet of the steam ejector is connected to the first steam buffer tank.

[0015] Furthermore, the heating system includes a steam replenishment unit, which includes a steam generator and a second steam buffer tank connected in sequence. The inlet of the steam generator is connected to a softened water tank through a second water pipe, and the steam outlet of the steam generator is connected to the inlet of the second steam buffer tank. A heat replenishment pipe is provided at the outlet of the second steam buffer tank, and the heat replenishment pipe is connected to the first steam buffer tank.

[0016] Furthermore, a reaction steam supply pipe is provided at the outlet of the second steam buffer tank, and the reaction steam supply pipe is connected to the synthesis reactor.

[0017] Furthermore, the first silo is equipped with a first feeding device at its outlet, and the second silo is equipped with a second feeding device at its outlet. The first feeding device is connected to the synthesis reactor, and the second feeding device is connected to the decomposition reactor.

[0018] Furthermore, the outlet of the second steam buffer tank is provided with a first material-carrying steam pipe, the outlet of the first feeding device is provided with a first feeding pipe, the synthesis reactor is provided with a first feeding pipeline, and the first material-carrying steam pipe or the first feeding pipe is provided with a first throttling device. The first material-carrying steam pipe and the first feeding pipe are respectively connected to the inlet of the first throttling device, and the outlet of the first throttling device is connected to the first feeding pipeline; the outlet of the second steam buffer tank is provided with a second material-carrying steam pipe, the outlet of the second feeding device is provided with a second feeding pipe, the decomposition reactor is provided with a second feeding pipeline, and the second material-carrying steam pipe or the second feeding pipe is provided with a second throttling device. The second material-carrying steam pipe and the second feeding pipe are respectively connected to the inlet of the second throttling device, and the outlet of the second throttling device is connected to the second feeding pipeline.

[0019] Furthermore, the discharge port of the decomposition reactor is provided with a first discharge pipe, which is connected to the inlet of the first gas-solid separation device. The steam outlet of the first gas-solid separation device is connected to a first steam pipe, and the calcium-based material outlet of the first gas-solid separation device is connected to the inlet of the first silo. The discharge port of the synthesis reactor is provided with a second discharge pipe, which is connected to the inlet of the second gas-solid separation device. The steam outlet of the second gas-solid separation device is connected to a second steam pipe, and the calcium-based material outlet of the second gas-solid separation device is connected to the inlet of the second silo.

[0020] A thermochemical thermal energy storage and heating method is applied to the aforementioned thermochemical thermal energy storage and heating system. The heating method includes an energy storage and heating process and an energy release and heating process. In the energy storage and heating process, calcium hydroxide stored in a second silo is transported to a decomposition reactor, where it is heated and decomposed by an energy supply device. The resulting calcium oxide is transported to a first silo for storage, and the generated superheated steam is transported to a first steam buffer tank for supplying steam to the steam-using system. In the energy release and heating process, calcium oxide stored in the first silo is transported to a synthesis reactor, and steam is supplied to the synthesis reactor. In the synthesis reactor, calcium oxide reacts with water to release heat, and the heat is transported to the first steam buffer tank in the form of superheated steam for supplying steam to the steam-using system. The generated calcium hydroxide is transported to the second silo for storage.

[0021] A thermochemical thermal energy storage system includes an energy storage system, an energy storage unit, an energy release system, and an energy release unit connected sequentially. In the energy storage system, solid materials are circulated and transported. The solid materials include high-chemical-energy materials and low-chemical-energy materials. Following the transport sequence of the solid materials, in the energy storage system, the low-chemical-energy materials react with heat to generate high-chemical-energy materials, achieving chemical thermal energy storage. The energy storage unit stores the generated high-chemical-energy materials. In the energy release system, the high-chemical-energy materials react to generate low-chemical-energy materials, releasing chemical energy as heat. The energy release unit stores the generated low-chemical-energy materials.

[0022] Furthermore, the energy storage system has a heater for heating solid materials.

[0023] Furthermore, the solid material is a calcium-based energy storage system.

[0024] Furthermore, high-chemical-energy materials include calcium oxide particles, and low-chemical-energy materials include calcium hydroxide particles.

[0025] A thermochemical thermal energy storage method is applied to the above-mentioned thermochemical thermal energy storage system. The energy storage method adopts a thermochemical energy storage system of Ca(OH)2 / CaO and stores energy through the mutual conversion between thermal energy and chemical energy. The energy storage method includes an energy storage stage and an energy release stage.

[0026] Compared with existing technologies, the thermochemical thermal energy storage and heating system and method described in this invention have the following advantages:

[0027] This invention discloses a thermochemical thermal energy storage and heating system and method. By incorporating a thermochemical thermal storage device, it avoids the use of conventional boilers, fully utilizing off-peak electricity hours for chemical thermal energy storage and heating. During peak electricity hours, it only uses chemical thermal energy storage for chemical heat release for heating, effectively shaving off peak and filling valley electricity demand, eliminating the carbon emission problems of conventional heating systems, and also helping to reduce electricity costs. Furthermore, this application generates superheated steam during both the chemical thermal energy storage and chemical heat release processes. This superheated steam is collected in a first steam buffer tank and can be supplied to external steam-using systems.

[0028] Compared with existing technologies, the thermochemical thermal energy storage system and energy storage method described in this invention have the following advantages:

[0029] The thermochemical thermal energy storage system and method described in this invention can perform thermochemical energy storage of high-temperature waste heat generated in industrial activities, minimizing the waste of industrial thermal energy; it can also utilize the peak shaving and valley filling effect of electricity to make the best and most effective use of electricity, increase the proportion of electricity used in industrial activities, reduce the dispersed and inefficient use of fossil fuels, and greatly reduce carbon emissions and air pollutant emissions. Attached Figure Description

[0030] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0031] Figure 1 is a schematic diagram of the thermochemical thermal energy storage and heating system according to an embodiment of the present invention;

[0032] Figure 2 is a schematic diagram of the structure between the gas-solid separation device, the silo, and the feeding device in the thermochemical thermal energy storage and heating system according to an embodiment of the present invention.

[0033] Figure 3 is a schematic diagram of a material feeding method in the thermochemical thermal energy storage and heating system according to an embodiment of the present invention.

[0034] Figure 4 is a schematic diagram of another material feeding method of the silo in the thermochemical thermal energy storage and heating system according to an embodiment of the present invention;

[0035] Figure 5 is a schematic diagram of a thermochemical thermal energy storage system according to an embodiment of the present invention;

[0036] Figure 6 is a schematic diagram of the energy storage system in a thermochemical thermal energy storage system according to an embodiment of the present invention;

[0037] Figure 7 is a schematic diagram of an energy release system in a thermochemical thermal energy storage system according to an embodiment of the present invention.

[0038] Figure 8 is a schematic diagram of a water vapor treatment process in an H2O unit of a thermochemical thermal energy storage system according to an embodiment of the present invention.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1. Decomposition reactor; 2. Power supply device; 3. First discharge pipeline; 4. First gas-solid separation device; 5. First steam pipeline; 6. First silo; 7. First feeding device; 8. First feeding pipe; 9. First steam buffer tank; 91. Steam supply pipeline; 92. Steam system; 93. Circulation pipe; 10. First feed pipeline; 11. Synthesis reactor; 12. Second discharge pipeline; 13. Second gas-solid separation device; 14. Second steam pipeline; 15. Second silo; 16. Second feeding device; 17. Second feeding pipe; 18. Second feed pipeline; 19. Makeup water source; 20. First water pump; 21. Softened water tank; 22. First water pipe; 23. Heat exchanger 24. Heat exchanger; 25. Water storage tank; 26. Second water pump; 27. Heat exchange equipment; 28. Steam ejector; 29. ​​Second water pipe; 30. Third water pump; 31. Steam generator; 32. Second steam buffer tank; 33. Heat exchanger pipe; 34. Reaction steam supply pipe; 35. First material loading steam pipe; 36. First throttling device; 37. Second material loading steam pipe; 38. Second throttling device; 39. First stage separator; 40. First material collection pipe; 42. Second stage separator; 43. Second material collection pipe; 44. Loss-in-weight scale; 45. Screw feeder; 46. Tank body support lug; 47. Weighing module; 48. Controller; 49. Signal line; 50. Feedback regulating valve. Detailed Implementation

[0041] The inventive concepts of this disclosure will be described below using terminology commonly used by those skilled in the art to communicate the essence of their work to others skilled in the art. However, these inventive concepts may be embodied in many different forms and should not be construed as limited to the embodiments described herein.

[0042] It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of this invention can be combined with each other. Arrows in the accompanying drawings indicate the flow direction of the relevant materials. Following the conventional alphabetical order, AT in the drawings refers to the corresponding valve. Given that "pipeline valve installation" is relatively common, this application does not need to provide a textual description of the installation of each valve; rather, it is preferable to refer to the accompanying drawings for easier explanation and understanding of the solution.

[0043] Due to certain structural similarities, the specific configuration in Figure 2 can be the first gas-solid separation device 4, the first silo 6, the first feeding device 7 and their related specific structural configurations, or it can be the second gas-solid separation device 13, the second silo 15, the second feeding device 16 and their related specific structural configurations. The corresponding reference numerals are also distinguished in parentheses for ease of understanding.

[0044] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0045] Example 1

[0046] This embodiment proposes a thermochemical thermal energy storage and heating system, as shown in Figures 1-4. The heating system includes a first steam buffer tank 9 and a thermochemical thermal energy storage device. The thermochemical thermal energy storage device includes a decomposition reactor 1, a first silo 6, a synthesis reactor 11, and a second silo 15 connected end to end. The thermochemical thermal energy storage device contains calcium-based materials that can be circulated and transported. The calcium-based materials include calcium hydroxide particles and calcium oxide particles. The decomposition reactor 1 is equipped with an energy supply device 2, which decomposes calcium hydroxide to generate calcium oxide and superheated steam. The first silo 6 is used to store the calcium oxide generated in the decomposition reactor 1, thereby realizing the chemical thermal energy storage process.

[0047] The circulation pipe 93 of the first steam buffer tank 9 is connected to the synthesis reactor 11, enabling a portion of the steam in the first steam buffer tank 9 to be transported into the synthesis reactor 11. This allows calcium oxide to react with water vapor to produce calcium hydroxide. The heat released from the reaction heats excess water vapor to generate superheated steam, thus releasing chemical energy as heat energy, achieving a chemical exothermic process. The second silo 15 is used to store the calcium hydroxide produced in the synthesis reactor 11. The inlet of the first steam buffer tank 9 is connected to the decomposition reactor 1 via the first steam pipe 5 and to the synthesis reactor 11 via the second steam pipe 14, used to collect the superheated steam produced in the decomposition reactor 1 and the synthesis reactor 11. The first steam buffer tank 9 has a steam supply pipe 91, which connects the first steam buffer tank 9 to an external steam system 92. Furthermore, considering that the moisture inside the synthesis reactor 11 mainly participates in the reaction and the amount of steam that can be supplied to the outside is limited, the synthesis reactor 11 may not be connected to the first steam buffer tank 9. The outlet of the synthesis reactor 11 can be set to the second steam pipeline 14, and the second steam pipeline 14 is vented, that is, the steam produced by the synthesis reactor 11 is vented through the second steam pipeline 14.

[0048] Alternatively, the second steam pipeline 14 can be kept connected to the synthesis reactor 11 and the first steam buffer tank 9, and an additional venting branch pipe can be installed in the second steam pipeline 14 to vent appropriately according to actual production needs.

[0049] The energy supply device 2 is an electric heater and / or a high-temperature waste heat pipeline (e.g., industrial high-temperature waste gas at approximately 610°C), which can fully utilize industrial waste heat, improve the utilization rate of waste heat resources, and avoid heat energy waste. Furthermore, the energy supply device 2 is preferably an electric heater, which can fully utilize the peak-shaving and valley-filling effect of electricity. During off-peak hours, the decomposition reactor 1 performs a chemical heat storage process to convert electrical energy into chemical energy, and during peak hours, the synthesis reactor 11 performs a chemical exothermic process, releasing chemical energy as heat energy, thus optimizing and effectively utilizing electrical energy. The steam system 92 can be a production system that uses steam to participate in production, reactions, etc., or a heat exchange system that utilizes the heat carried by steam for heat extraction and utilization. Of course, if the steam system 92 controls the pressure and temperature of superheated steam to meet the requirements of civil heating, it can also be integrated into a conventional civil heating network.

[0050] Therefore, the heating system of this application, by setting up a thermochemical thermal storage device, avoids the use of conventional boilers, and can make full use of off-peak electricity periods for chemical thermal energy storage and heating. During peak electricity periods, it only uses chemical thermal energy storage for chemical heat release for heating, which can effectively smooth out peak and valley electricity consumption, eliminate the carbon emission problems of conventional heating systems, and also help reduce electricity costs. At the same time, this application can generate superheated steam in both the chemical thermal energy storage process and the chemical heat release process. The superheated steam is collected by the first steam buffer tank 9 and can be provided to the external steam system 92. In addition, by setting up a circulation pipe 93, the first steam buffer tank 9 can provide reactants (water or steam) to the synthesis reactor 11, and the heat released by the synthesis reaction can be used to heat the water medium to generate superheated steam for external use.

[0051] The heating system includes a water supply unit, which includes a water supply source 19, a softened water tank 21, a heat exchanger 23, and a water storage tank 25 connected in sequence. The water supply source 19 can be a conventional industrial water supply source. The water supply source 19 supplies water to the softened water tank 21 through a first water pump 20. The water is softened by the softened water tank 21. The softened water tank 21 is equipped with a first water pipe 22, which is connected to the low-temperature medium flow channel of the heat exchanger 23. The first steam pipe 5 is connected to the high-temperature medium flow channel of the heat exchanger 23. In the heat exchanger 23, the softened water exchanges heat with the superheated steam produced in the decomposition reactor 1. Preferably, after heat exchange, the superheated steam produced in the decomposition reactor 1 is cooled from 610°C to 180°C. The cooled superheated steam is transported to the first steam buffer tank 9, and the softened water after heat exchange is transported to the water storage tank 25 for later use. This allows some electrical energy to be converted into heat energy for softening water and stored during off-peak hours, so that it can be used during peak hours.

[0052] Preferably, a heat exchanger 24 is provided at the inlet of the water storage tank 25, so that if the softened water after heat exchange by the heat exchanger 23 does not reach a certain temperature, the heat exchanger 24 can further heat the softened water so that the water entering the water storage tank 25 has a sufficiently high water temperature.

[0053] Furthermore, the synthesis reactor 11 is equipped with a heat exchange device 27 for heat exchange within the reactor 11. The heat exchange device 27 can be located inside or outside the reactor 11; for example, a coil structure can be used as the heat exchange component of the heat exchange device 27. The coil structure can be located inside the reactor 11 or attached to its outer wall, both achieving heat exchange. The outlet of the water storage tank 25 is connected to the inlet of the heat exchange device 27, and the outlet of the heat exchange device 27 is connected to the first steam buffer tank 9. Thus, during peak power periods, when the synthesis reactor 11 releases a large amount of heat per unit time, the spare water in the water storage tank 25 provides timely heat exchange, forming superheated water or superheated steam in the pipeline, which is then transported to the first steam buffer tank 9. This effectively and promptly removes a large amount of heat from the synthesis reactor 11, avoiding the situation where relying solely on the water supplied to the synthesis reactor 11 through the circulation pipe 93 is insufficient to remove a large amount of heat quickly and promptly. It also prevents excessively high temperatures within the synthesis reactor 11, thus reducing safety hazards. For the output of the backup water in the water storage tank 25, a second water pump 26 can be installed in the outlet pipeline of the water storage tank 25. The water pump will cause the water in the water storage tank 25 to flow into the heat exchange equipment 27 and remove the heat generated in the synthesis reactor 11 in time.

[0054] Preferably, a steam ejector 28 is provided at the outlet of the second steam pipeline 14 or the heat exchange device 27. The outlets of the second steam pipeline 14 and the heat exchange device 27 are both connected to the inlet of the steam ejector 28. The outlet of the steam ejector 28 is connected to the first steam buffer tank 9. Thus, by providing the steam ejector 28, the superheated steam output from the second steam pipeline 14 (directly generated and produced in the synthesis reactor 11) and the superheated water and superheated steam after heat exchange of the softened water output from the water storage tank 25 can be mixed by the steam ejector 28 before being transported to the first steam buffer tank 9. This helps to maintain the internal temperature distribution of the first steam buffer tank 9 and avoids excessively hot steam impacting the first steam buffer tank 9.

[0055] In addition to the water supply unit, the heating system also includes a steam supply unit. The steam supply unit can have a separate water supply unit. In this application, the water source for the steam supply unit can be used in conjunction with the water supply unit. Specifically, the steam supply unit includes a steam generator 31 and a second steam buffer tank 32 connected in sequence. The inlet of the steam generator 31 is connected to a softened water tank 21 via a second water pipe 29. The second water pipe 29 is equipped with a third water pump 30, used to pump softened water from the softened water tank 21 to the steam generator 31. The steam outlet of the steam generator 31 is connected to the inlet of the second steam buffer tank 32. Thus, when additional steam is needed, softened water from the softened water tank 21 can be used, heated to produce steam, and then delivered to the second steam buffer tank 32 for later use. This also allows the steam supply unit and the water supply unit to share a single water supply assembly, which helps reduce the complexity of the water supply circuit and the entire system. Preferably, the steam generator 31 is an electrically heated steam generator capable of providing approximately 200°C steam to the second steam buffer tank 32.

[0056] The outlet of the second steam buffer tank 32 is provided with a reaction steam supply pipe 34, which is connected to the synthesis reactor 11. When the amount of circulating steam supplied to the synthesis reactor 11 from the first steam buffer tank 9 through the circulation pipe 93 is insufficient, or when the synthesis reactor 11 has just started operating, or when there are large fluctuations in the first steam buffer tank 9, or under other unconventional circumstances, the steam from the second steam buffer tank 32 can be used to replenish the synthesis reactor 11. Preferably, the reaction steam supply pipe 34 is connected to the circulation pipe 93, allowing them to share a section of pipe. Correspondingly, a valve Q is installed at the end of the reaction steam supply pipe 34 near the second steam buffer tank 32, and a valve R is installed at the end of the circulation pipe 93 near the first steam buffer tank 9. These valves allow for the separate control of the on / off state and opening degree of the reaction steam supply pipe 34 and the circulation pipe 93.

[0057] In addition, a heat replenishment pipe 33 is provided at the outlet of the second steam buffer tank 32. The heat replenishment pipe 33 is connected to the first steam buffer tank 9. Thus, when there is attenuation or fluctuation in the first steam buffer tank 9, or when the steam in the first steam buffer tank 9 alone is insufficient to meet the steam supply conditions to the outside, steam can be replenished to the first steam buffer tank 9 through the second steam buffer tank 32, so as to ensure that the heating system can provide superheated steam to the outside relatively stably and continuously.

[0058] For the discharge of calcium-based materials from the corresponding silos, both the discharge port of the first silo 6 and the discharge port of the second silo 15 are equipped with feeding devices, referred to as the first feeding device 7 and the second feeding device 16, respectively. The first feeding device 7 is connected to the synthesis reactor 11 and is used to transport calcium oxide particles from the first silo 6 to the synthesis reactor 11. The second feeding device 16 is connected to the decomposition reactor 1 and is used to transport calcium hydroxide particles from the second silo 15 to the decomposition reactor 1.

[0059] As shown in Figure 2, the feeding device includes a loss-in-weight scale 44 and a screw feeder 45 connected in sequence. The inlet of the loss-in-weight scale 44 is connected to the outlet of the first silo 6 or the second silo 15, and the outlet of the loss-in-weight scale 44 is connected to the inlet of the screw feeder 45. The outlet of the screw feeder 45 is provided with a feeding pipe, which is connected to the synthesis reactor 11 or the decomposition reactor 1. The structures of the first feeding device 7 and the second feeding device 16 are similar, and the structure of the feeding device can be adopted. Specific silos and reactors can be connected according to actual conditions, which will not be described in detail here. Thus, through the loss-in-weight scale 44, a specific amount of calcium-based material can be provided according to actual needs, and then the calcium-based material can be conveyed under the drive of the screw feeder 45.

[0060] Furthermore, this application is not limited to the feeding methods of the loss-in-weight scale 44 and the screw feeder 45; this application proposes several other feeding methods.

[0061] As shown in Figure 3, the feeding device includes a screw feeder 45. The inlet of the screw feeder 45 is connected to the outlet of the first hopper 6 or the second hopper 15. The outlet of the screw feeder 45 is provided with a feeding pipe, which is connected to the synthesis reactor 11 or the decomposition reactor 1. Referring to the form in Figure 2, the hopper and the loss-in-weight scale can also be integrated into one unit to form a hopper with a weighing component, as shown in Figure 3. During feeding, the material mass flow rate is measured by the loss-in-weight scale, and the screw speed of the screw feeder 45 is controlled simultaneously to adjust the feeding amount.

[0062] As shown in Figure 4, this application can eliminate the need for a separate feeding device, instead using feedback adjustment of the feeding valve based on the weight change of the entire silo. Specifically, both the tank support lugs 6 of the first silo 6 and the tank support lugs 6 of the second silo 15 are equipped with weighing modules 47. The weighing modules 47 can detect the overall weight of the silo (including the material) in real time. The feeding ports of both the first silo 6 and the second silo 15 are equipped with feedback regulating valves 50. The weighing modules 47 and the feedback regulating valves 50 are connected to the controller 48 via signal lines 49. During the feeding process, the weighing modules 47 send the detected weight value to the controller 48. The controller 48 determines the feeding status based on the decrease in weight value or the decrease in weight value per unit time, and adjusts the opening of the feedback regulating valves 50. For example, based on the actual material demand, the opening of the feedback regulating valves 50 can be increased, decreased, or opened and closed.

[0063] For ease of understanding, the scheme in Figure 4 can be considered as a simplified version of Figure 1, omitting the first feeding device 7 and the second feeding device 16, and adapting the corresponding pipelines. The first hopper 6 is connected to the first feeding pipe 8 via valve C, and the second hopper 15 is connected to the second feeding pipe 17 via valve H. Correspondingly, the feedback regulating valve 50 in Figure 4 corresponds to the schematic diagrams of valves C and H in Figure 1. Functionally, the combination of the weighing module 47, the controller 48, and the feedback regulating valve 50 can be considered a "feeding component" capable of providing precise feeding control.

[0064] For the conveying of calcium oxide particles, the outlet of the second steam buffer tank 32 is provided with a first material-carrying steam pipe 35, the outlet of the first feeding device 7 is provided with a first feeding pipe 8, the synthesis reactor 11 is provided with a first feeding pipeline 10, and the first material-carrying steam pipe 35 or the first feeding pipe 8 is provided with a first throttling device 36. The first material-carrying steam pipe 35 and the first feeding pipe 8 are respectively connected to the inlet of the first throttling device 36, and the outlet of the first throttling device 36 is connected to the first feeding pipeline 10. The first throttling device 36 is preferably a Venturi tube. For the structure of the Venturi tube, the existing technology can be directly adopted. Preferably, the first material-carrying steam pipe 35 is connected to the end inlet of the first throttling device 36, and the first feeding pipe 8 is connected to the negative pressure inlet of the first throttling device 36.

[0065] Correspondingly, for the conveying of calcium hydroxide particles, the outlet of the second steam buffer tank 32 is provided with a second material-carrying steam pipe 37, the outlet of the second feeding device 16 is provided with a second feeding pipe 17, the decomposition reactor 1 is provided with a second feeding pipeline 18, the second material-carrying steam pipe 37 or the second feeding pipe 17 is provided with a second throttling device 38, the second material-carrying steam pipe 37 and the second feeding pipe 17 are respectively connected to the inlet of the second throttling device 38, and the outlet of the second throttling device 38 is connected to the second feeding pipeline 18; preferably, the second throttling device 38 is a venturi tube, the second material-carrying steam pipe 37 is connected to the end inlet of the second throttling device 38, and the second feeding pipe 17 is connected to the negative pressure inlet of the second throttling device 38.

[0066] By configuring the corresponding steam pipe and venturi tube in the second steam buffer tank 32, the calcium-based material, after being transported out of the silo, can be easily and conveniently transported to the corresponding reactor by the steam flow. In particular, after the steam flow carries the calcium oxide to the synthesis reactor 11, the water vapor, as the carrier gas, can continue to participate in the reaction within the synthesis reactor 11, ensuring that the carrier gas is fully utilized.

[0067] Regarding the discharge of calcium-based materials from the reactor, since steam is mainly used as the carrier gas to transport the calcium-based materials in this application, gas-solid separation devices are provided at the discharge ports of the decomposition reactor 1 and the synthesis reactor 11, respectively referred to as the first gas-solid separation device 4 and the second gas-solid separation device 13.

[0068] Specifically, the discharge port of the decomposition reactor 1 is provided with a first discharge pipe 3, which is connected to the inlet of the first gas-solid separation device 4. The steam outlet of the first gas-solid separation device 4 is connected to a first steam pipe 5, and the calcium-based material outlet of the first gas-solid separation device 4 is connected to the inlet of the first silo 6. Preferably, the calcium-based material outlet of the first gas-solid separation device 4 is located directly above the inlet of the first silo 6, so that the separated calcium-based material can automatically fall into the first silo 6 under its own gravity.

[0069] Accordingly, the outlet of the synthesis reactor 11 is provided with a second discharge pipe 12, which is connected to the inlet of the second gas-solid separation device 13. The steam outlet of the second gas-solid separation device 13 is connected to a second steam pipe 14, and the calcium-based material outlet of the second gas-solid separation device 13 is connected to the inlet of the second silo 15. Preferably, the calcium-based material outlet of the second gas-solid separation device 13 is located directly above the inlet of the second silo 15.

[0070] The gas-solid separation device includes a first-stage separator 39 and a second-stage separator 42. The inlet of the first-stage separator 39 is connected to the first outlet pipe 3 or the second outlet pipe 12. The steam outlet of the first-stage separator 39 is connected to the inlet of the second-stage separator 42. The calcium-based material outlet of the first-stage separator 39 is provided with a first collection pipe 40. The steam outlet of the second-stage separator 42 is connected to the first steam pipe 5 or the second steam pipe 14. The calcium-based material outlet of the second-stage separator 42 is provided with a second collection pipe 43. Both the first collection pipe 40 and the second collection pipe 43 are connected to the first silo 6 or the second silo 15. Preferably, the first material collection pipe 40 and the second material collection pipe 43 can share a section of pipe structure on the side closest to the silo, or in other words, the first material collection pipe 40 is connected to the silo and the outlet of the second material collection pipe 43 is connected to the first material collection pipe 40; or the second material collection pipe 43 is connected to the silo and the outlet of the first material collection pipe 40 is connected to the second material collection pipe 43.

[0071] Furthermore, the gas-solid separation device of this application is not limited to the form of a first-stage separator 39 and a second-stage separator 42, but can also be composed of multiple dust collectors connected in series. These dust collectors can be cyclone separators, bag filters, wire mesh dust collectors, wet electrostatic precipitators, molecular sieve adsorption dust collectors, etc. Since specific dust removal equipment and principles can be found in existing technologies, they will not be elaborated upon here.

[0072] Therefore, by setting up a two-stage separator, this application can efficiently separate calcium-based materials from steam, preventing calcium-based materials from entering the steam pipeline, the first steam buffer tank 9, or even the steam supply network with the steam. This not only prevents the loss of calcium-based materials but also helps ensure the cleanliness of steam-related pipelines and equipment, thus preventing blockages. Preferably, the first-stage separator 39 is a cyclone separator, and the second-stage separator 42 is a metal filter bag filter.

[0073] Example 2

[0074] This embodiment, based on Embodiment 1, proposes a thermochemical thermal energy storage and heating method. The method includes an energy storage heating process and an energy release heating process. The energy storage heating process is preferably carried out during off-peak electricity hours, but is not limited to off-peak hours; in some cases, it can also be carried out during normal or peak electricity hours. The energy release heating process can be carried out according to actual conditions such as system operating status, external heating demand, and peak and off-peak electricity hours, for example, during peak electricity hours.

[0075] The energy storage and heating process involves transporting the calcium hydroxide stored in the second silo 15 to the decomposition reactor 1, where the calcium hydroxide is heated and decomposed by the energy supply device 2. The resulting calcium oxide is then transported to the first silo 6 for storage, and the generated superheated steam is transported to the first steam buffer tank 9 to supply steam to the steam system 92.

[0076] The energy release and heat supply process transports the calcium oxide stored in the first silo 6 to the synthesis reactor 11 and supplies steam into the synthesis reactor 11. The calcium oxide reacts with water in the synthesis reactor 11 to release heat, and the heat is transported to the first steam buffer tank 9 in the form of superheated steam to supply steam to the steam system 92. The generated calcium hydroxide is transported to the second silo 15 for storage.

[0077] The thermochemical thermal energy storage and heating system includes a central processing unit (CPU), which is used to regulate the operation of related equipment and valve openings during the energy storage and heating process and the energy release and heating process. A first pressure detector is installed in the first steam buffer tank 9, and a second pressure detector is installed in the second steam buffer tank 32. Both the first and second pressure detectors are connected to the CPU and are used to acquire the steam pressure in the first steam buffer tank 9 and the second steam buffer tank 32 in real time. The first and second pressure detectors are superheated steam pressure instruments, which can be purchased commercially and will not be described in detail here.

[0078] The energy storage and heating process includes:

[0079] S1. Water is supplied to the softening tank 21 through the water supply source 19 and the water is softened.

[0080] The operation and related technologies for softening water can be directly adopted from existing technologies and will not be elaborated upon. For water delivery, turning on the first water pump 20 and valve J will supply water to the softening water tank 21 through the water supply source 19.

[0081] S2. The softened water in the softened water tank 21 is transported to the steam generator 31 to generate superheated steam, and the superheated steam is sent into the second steam buffer tank 32.

[0082] The steam generator 31 can provide superheated steam at about 200°C and 0.5MPa. Correspondingly, opening valve N and the third water pump 30 can deliver softened water to the steam generator 31; opening valve O allows the produced superheated steam to enter the second steam buffer tank 32.

[0083] S3. The pressure P2 inside the second steam buffer tank 32 is detected in real time by the second pressure detector;

[0084] S4. Determine whether P2 ≥ the first preset pressure; if yes, proceed to step S5; if no, return to step S2.

[0085] The first preset pressure can be considered as the start-up pressure condition of the decomposition reactor 1, or as the steam pressure condition for the calcium hydroxide particles. Preferably, the first preset pressure is 0.4 MPa. The central processing unit acquires P2 in real time and makes a determination according to step S4, which is beneficial to realize automated and intelligent control of the start-up of the decomposition reactor 1, as well as more precise adjustment.

[0086] S5. Open the second material loading steam pipe 37 and the second feeding device 16, and use the material loading steam to transport the calcium hydroxide in the second silo 15 to the decomposition reactor 1.

[0087] Accordingly, valves H and T need to be opened so that the feed steam and calcium hydroxide can enter the decomposition reactor 1 through the second feed pipeline 18.

[0088] S6. Start the power supply device 2 to decompose the calcium hydroxide in the decomposition reactor 1 into calcium oxide and superheated steam;

[0089] Among them, the power supply device 2 can provide a high temperature of about 610°C, and the superheated steam produced by the decomposition reaction is about 610°C and 0.3 MPaG.

[0090] S7. The steam and solid particles discharged from the outlet of the decomposition reactor 1 are separated by the first gas-solid separation device 4.

[0091] In this process, valve A is opened, and the decomposition reactor 1 discharges material. The material from the decomposition reactor 1 undergoes first-stage gas-solid separation through a first-stage separator 39 (cyclone separator). Then, the separated gaseous material undergoes second-stage gas-solid separation using a second-stage separator 42 (metal bag filter), ensuring that the dust content of the superheated steam after the two-stage gas-solid separation is <5 mg / m³. 3 Open valve B to allow the separated solid particles (mostly calcium oxide and a small amount of calcium hydroxide) to fall into the first hopper 6.

[0092] S8. The superheated steam after gas-solid separation and the softened water in the softened water tank 21 exchange heat through the heat exchanger 23. The superheated steam after heat exchange enters the first steam buffer tank 9.

[0093] In this process, valve K is opened, allowing softened water to be transported through the first water pipe 22 to the heat exchanger 23, where it exchanges heat with superheated steam at 610°C. The superheated steam is then cooled to approximately 180°C and enters the first steam buffer tank 9 to provide steam to the steam-using system 92. Meanwhile, the softened water at room temperature is heated to approximately 83°C after the heat exchange. It can then be further heated by the supplementary heater 24 to approximately 144°C (close to saturation) before being transported to the water storage tank 25 for storage and use in the energy release heating process.

[0094] In addition, considering the stability of the steam supply from the first steam buffer tank 9, the energy storage heating process also includes:

[0095] S9. The pressure P1 inside the first steam buffer tank 9 is detected in real time by the first pressure detector;

[0096] S10. Determine whether P1 < the second preset pressure; if yes, proceed to step S11; if no, open the steam supply pipeline 91 to supply steam to the steam consumption system 92.

[0097] The second preset pressure can be considered as the lower limit of the pressure required to supply steam to the outside. Preferably, the second preset pressure is 0.3 MPa. By acquiring P1 in real time and making a determination according to step S10, the central processing unit can automate and intelligently control the process of the first steam buffer tank 9 supplying steam to the outside, and make more precise adjustments.

[0098] S11. Turn on the heat replenishment pipe 33, use the superheated steam in the second steam buffer tank 32 to replenish the first steam buffer tank 9, and return to step S3.

[0099] In particular, since the pressure and temperature inside the second steam buffer tank 32 are relatively high, when the pressure inside the first steam buffer tank 9 is insufficient or the external steam demand is large, the second steam buffer tank 32 can replenish the steam inside the first steam buffer tank 9 in a timely and efficient manner, which is conducive to maintaining the stability of the steam supply from the first steam buffer tank 9. At the same time, regardless of fluctuations during the energy storage heating process or a sudden increase in the external steam demand, the heating system can ensure that it can stably and continuously supply steam to the outside, which is conducive to improving the operational flexibility of the heating system.

[0100] For steps S9-S11, they can be performed after step S8 in the energy storage heating process, or they can be performed in real time during the entire energy storage heating process, so as to ensure that the first steam buffer tank 9 can supply steam to the outside smoothly.

[0101] The energy release and heat supply process includes:

[0102] B1. Water is supplied to the softening tank 21 through the water supply source 19 and the water is softened.

[0103] B2. The softened water in the softened water tank 21 is transported to the steam generator 31 to generate superheated steam, and the superheated steam is sent into the second steam buffer tank 32.

[0104] B3. The pressure P2 inside the second steam buffer tank 32 is detected in real time by the second pressure detector;

[0105] B4. Determine if P2 ≥ the first preset pressure; if yes, proceed to step B5; if no, return to step B2.

[0106] Steps B1-B4 are the same as steps S1-S4 and will not be described again. Whether it's the energy storage heating process or the energy release heating process, these four steps are all related to reactor start-up operations. They ensure that the second steam buffer tank 32 has a certain pressure, preparing in advance for production needs such as solid material transportation, steam supply, and potential steam replenishment from the first steam buffer tank 9, thus guaranteeing the smooth start-up and operation of both the energy storage heating process and the energy release heating process.

[0107] B5. Open the first material loading steam pipe 35 and the first feeding device 7 to transport the calcium oxide in the first material bin 6 to the synthesis reactor 11 through the material loading steam; at the same time, open the reaction steam supply pipe 34 and / or the circulation pipe 93 to supply sufficient steam to the synthesis reactor 11 through the second steam buffer tank 32 and / or the first steam buffer tank 9 as reactants to maintain the synthesis reaction.

[0108] Correspondingly, valves C and S need to be opened to allow the feed steam and calcium oxide to enter the synthesis reactor 11 through the first feed pipeline 10. Simultaneously, if the entire heating system is in the start-up phase and not yet running smoothly, or if there is insufficient steam in the first steam buffer tank 9, step B5 can simply open valve Q to supply steam from the second steam buffer tank 32 to the synthesis reactor 11 via the reaction steam supply pipe 34. If there is sufficient steam in the first steam buffer tank 9, step B5 can simply open valve R to supply steam from the first steam buffer tank 9 to the synthesis reactor 11 via the circulation pipe 93. Of course, at this time, the opening degrees of valves R and Q can also be opened and adjusted simultaneously to regulate the amount of steam that can be supplied by both the first steam buffer tank 9 and the second steam buffer tank 32, thus avoiding large fluctuations in the amount of steam in the first steam buffer tank 9.

[0109] In this embodiment, if step B5 is regarded as the system just starting up, it is preferable to only open the reaction steam supply pipe 34, while the circulation pipe 93 is closed.

[0110] B6. Calcium oxide reacts with some water vapor in the synthesis reactor 11, releasing a large amount of heat. Water in the storage tank 25 is transported to the heat exchanger 27 to absorb the heat generated in the synthesis reactor 11, producing steam A. Steam B and solid particles from the outlet of the synthesis reactor 11 are separated by the second gas-solid separation device 13. Both steam A and steam B are transported to the first steam buffer tank 9.

[0111] In step B6, the water in the storage tank 25 is preferably the near-saturated water stored in the storage tank 25 during step S8 of the energy storage heating process. By opening valve M and starting the second water pump 26, the water in the storage tank 25 can be transported to the heat exchange device 27. After heat exchange, superheated steam of about 0.3 to 0.35 MPaG and 180°C is generated, which is referred to as steam A for ease of explanation.

[0112] In step B5, sufficient steam is supplied to the synthesis reactor 11. Part of it participates in the reaction, and part serves as a carrier gas flow. As the reaction proceeds in the synthesis reactor 11, the carrier steam also absorbs heat and rises in temperature. When discharging from the synthesis reactor 11, valve E is opened, and the reactor 11 discharges its contents. The first-stage gas-solid separation is performed on the discharge from the synthesis reactor 11 by the first-stage separator 39 (cyclone separator). Then, the separated gaseous material undergoes a second-stage gas-solid separation using the second-stage separator 42 (metal bag filter), ensuring that the dust content of the superheated steam after the two-stage gas-solid separation is <5mg / m3. Valve G is then opened, allowing the separated solid particles (mostly calcium hydroxide and a small amount of calcium oxide) to fall into the second silo 15. Correspondingly, compared to steam A, the steam separated by the second gas-solid separation device 13 has a lower pressure (below 0.3MPaG) and a smaller output, and is denoted as steam B.

[0113] In this application, steam A and steam B enter the steam ejector 28 together, are thoroughly mixed, and then sent into the first steam buffer tank 9 to supply steam to the steam-using system 92.

[0114] Furthermore, taking into account both the supply of steam from the first steam buffer tank 9 to the outside environment and the provision of steam from the first steam buffer tank 9 through the circulation pipe 93, the energy release heating process also includes:

[0115] B7. The pressure P1 inside the first steam buffer tank 9 is detected in real time using the first pressure detector;

[0116] B8. Determine if P1 < the second preset pressure; if yes, proceed to step B9; if no, proceed to step B10.

[0117] The second preset pressure can be considered as the lower limit of the pressure required to supply steam to the outside. Preferably, the second preset pressure is 0.3 MPa.

[0118] B9. Turn on the heat supply pipe 33, use the superheated steam in the second steam buffer tank 32 to replenish the steam in the first steam buffer tank 9, and return to step B3.

[0119] Because the pressure and temperature inside the second steam buffer tank 32 are relatively high, when the pressure inside the first steam buffer tank 9 is insufficient or the external steam demand is large, the second steam buffer tank 32 can replenish the steam inside the first steam buffer tank 9 in a timely and efficient manner, which helps to maintain the stability of the steam supply from the first steam buffer tank 9. At the same time, regardless of fluctuations during the energy release heating process or a sudden increase in the external steam demand, the heating system can ensure that it can stably and continuously supply steam to the outside, which helps to improve the operational flexibility of the heating system.

[0120] B10. Open the steam supply line 91 to supply steam to the steam consumption system 92;

[0121] In this process, by adjusting valve I, the steam from the first steam buffer tank 9 is supplied to the steam-using system 92 through the steam supply pipeline 91.

[0122] B11. Determine if P1 ≥ the third preset pressure; if yes, proceed to step B12; if no, return to step B8.

[0123] B12, Circulation pipe 93 is open, reaction steam supply pipe 34 is closed.

[0124] The third preset pressure can be considered as the lower limit of the pressure required for the first steam buffer tank 9 to independently supply circulating steam (feed) to the synthesis reactor 11. Preferably, the third preset pressure is 0.34 MPa. The central processing unit acquires P1 in real time and makes a judgment according to step B11. If P1 is less than the third preset pressure, it means that the steam in the first steam buffer tank 9 has not yet reached the conditions for independent circulation feeding. Especially during the system start-up phase, the second steam buffer tank 32 still needs to supply a certain amount of steam to the synthesis reactor 11 through the reaction steam supply pipe 34. If P1 is greater than or equal to the third preset pressure, it means that the steam pressure in the first steam buffer tank 9 is sufficient and can meet the conditions for independent circulation feeding. At this time, the circulation pipe 93 is opened and the reaction steam supply pipe 34 is closed.

[0125] Thus, during the energy release heating process, through steps B7-B12, regardless of fluctuations during the energy release heating process or sudden increases in external steam demand, the heating system can ensure a stable and continuous supply of steam to the outside, which is beneficial to improving the operational flexibility of the heating system. Furthermore, by setting a third preset pressure, it is determined whether the first steam buffer tank 9 can independently circulate and supply material to the synthesis reactor 11. On the one hand, this helps ensure the supply of steam to the synthesis reactor 11, allowing for a more complete reaction within the reactor, which is beneficial for fully releasing the stored chemical energy and improving the efficiency of chemical energy to thermal energy conversion during the energy release heating process. On the other hand, after P1 ≥ the third preset pressure, the reaction steam supply pipe 34 can be closed in a timely manner, reducing the use of steam in the second steam buffer tank 32. Correspondingly, this helps reduce the load on the steam generator 31, minimizing additional power consumption during peak electricity periods.

[0126] The device design in Example 2 is as follows: 5 t / h of heating steam, steam temperature 0.3 MPaG, 180℃. Calculations are performed based on an 8-hour / day off-peak electricity period and a 16-hour / day peak-hour period; the system stores heat only during off-peak hours and releases heat during peak-hour periods, ensuring a continuous 24-hour steam supply of 5 t / h. The superheated steam volume data for both the energy storage and release heating processes are shown in Table 1 below.

[0127] During the energy storage and heating process:

[0128] The amount of superheated steam generated by steam generator 31 in S2 is 1 t / h;

[0129] The amount of superheated steam generated by power supply device 2 in S6 is 4.6 t / h;

[0130] The steam supply rate to the steam-using system 92 in S8 is 5 t / h;

[0131] The steam supply rate of the second steam buffer tank 32 in S11 is 0.4 t / h;

[0132] During the energy release heating process:

[0133] The amount of superheated steam generated by steam generator 31 in B2 is 2.3 t / h;

[0134] The steam output A from the synthesis reactor in B6 is 7.3 t / h; the steam output B from the outlet of synthesis reactor 11 is 0.5 t / h.

[0135] The steam supply to the second steam buffer tank 32 in B9 is 2.3 t / h (the maximum supply in the initial stage, which will gradually decrease to 0 later).

[0136] The thermochemical thermal energy storage heating system of this embodiment, assuming that all off-peak electricity is from new energy sources, and taking a heating capacity of 5t / h as an example, saves 11851.2t / a and 6969.6t / a of carbon dioxide emissions per year compared with coal-fired or natural gas boilers.

[0137] The thermochemical thermal energy storage heating system in this embodiment has a design capacity of 5 t / h of heating steam and an energy storage capacity of 12 MW / 96 MWh, with a storage duration of 8 hours. This technology can play an important supporting role in overcoming the challenges of grid peak shaving and the integration of new energy power.

[0138] Since it primarily uses off-peak electricity as its heat source, without considering peak-shaving subsidies, and taking peak-valley-flat electricity prices of 1.1, 0.29, and 0.7 yuan / kWh respectively as examples, its electricity cost can be reduced by approximately 58% compared to conventional electric boilers. If peak-shaving subsidies and carbon emission benefits are taken into account, its heating cost will be even lower.

[0139] Example 3

[0140] This embodiment proposes a thermochemical thermal energy storage system, as shown in Figure 5. The energy storage system includes an energy storage system, an energy storage unit, an energy release system, and an energy release unit connected in sequence. Specifically, in terms of the direction of solid material movement, the solid material outlet of the energy storage system is connected to the inlet of the energy storage unit, the outlet of the energy storage unit is connected to the solid material inlet of the energy release system, the solid material outlet of the energy release system is connected to the inlet of the energy release unit, and the outlet of the energy release unit is connected to the solid material inlet of the energy storage system.

[0141] The energy storage system includes a heater for heating solid materials, such as high-temperature industrial waste heat heating, electric heating, electromagnetic heating, etc.

[0142] In this embodiment, the solid material can store (release) energy through a chemical reaction within the energy storage system (energy release system). Specifically, the solid material in this embodiment includes both high-chemical-energy and low-chemical-energy materials. In the energy storage system, a heater causes the low-chemical-energy material to react and generate the high-chemical-energy material, thus performing a chemical energy storage process. In the energy release system, the high-chemical-energy material reacts to generate the low-chemical-energy material, releasing the chemical energy, at least as thermal energy. The energy storage unit stores the high-chemical-energy material, and the energy release unit stores the low-chemical-energy material.

[0143] The solid material is a calcium-based energy storage system, preferably CaO particles (high chemical energy material) or Ca(OH)2 particles (low chemical energy material). The energy storage unit includes at least one CaO particle storage tank, and the energy release unit includes at least one Ca(OH)2 particle storage tank. In this embodiment, the movement of the solid material can be achieved using a screw feeder, vibrating feeder, or crawler feeder.

[0144] Based on this, the energy storage system includes a fluidized bed reactor or a moving bed reactor.

[0145] If the energy storage system uses a fluidized bed reactor, the fluidizing medium can be at least one of the following: water vapor, nitrogen, carbon dioxide, or a conventional inert gas produced by the high-temperature decomposition of calcium hydroxide. As shown in Figure 6, the energy storage system also includes a gas-solid separator, a fluidizing medium driving device, and a heater. The solid material inlet of the fluidized bed reactor is connected to the outlet of the energy-releasing unit, allowing calcium hydroxide particles to be transported from the energy-releasing unit into the fluidized bed reactor. The fluidizing medium driving device provides power to the fluidizing medium, which is then heated to 600-700°C by the heater before entering the fluidized bed reactor. This ensures that the calcium hydroxide particles are in a fluidized state and provides a high-temperature environment for the decomposition reaction of calcium hydroxide. In the fluidized bed reactor, calcium hydroxide decomposes to produce calcium oxide particles and water vapor. The material outlet of the fluidized bed reactor is connected to the material inlet of the gas-solid separator. The calcium oxide particles and water vapor enter the gas-solid separator together. The gaseous material outlet of the gas-solid separator can be connected to the fluidizing medium drive device to use this water vapor as the fluidizing medium. It can also be connected to the subsequent H2O unit for water vapor recovery and utilization. The solid material outlet of the gas-solid separator is connected to the inlet of the energy storage unit.

[0146] If the energy storage system uses a moving bed reactor, the system may consist only of the moving bed reactor and a heater. The solid material, in addition to the calcium-based energy storage system, also includes iron-based particles. The heater in the energy storage system is preferably electromagnetically heated. In the moving bed reactor, the mixture of calcium hydroxide particles and iron-based particles, under electromagnetic heating, generates heat from the iron-based particles, providing a high-temperature environment for the decomposition reaction of the calcium hydroxide particles. The water vapor generated during decomposition directly separates from the solid material and is discharged from the gaseous material outlet of the moving bed reactor, which can then connect to the subsequent H2O unit. The mixture of calcium oxide particles and iron-based particles can be discharged from the solid material outlet of the moving bed reactor and enter the energy storage unit.

[0147] In addition to storing calcium oxide particles that store chemical energy, the energy storage unit also has a calcium oxide storage tank with an insulation jacket to reduce heat loss and store this high-temperature sensible heat, as the solid material discharged from the energy storage system (mainly calcium oxide particles) is around 500°C in actual applications.

[0148] When energy needs to be supplied to the outside world, the outlet of the energy storage unit can be opened to transport calcium oxide particles to the energy release system.

[0149] Similarly, the energy release system can be a fluidized bed reactor or a fixed bed reactor.

[0150] Taking the energy release system as an example of a fluidized bed reactor, as shown in Figure 5, the energy release system includes a fluidized bed reactor, a gas-solid separator, a heat exchanger, and a centrifugal fan. The fluidized bed reactor has a water inlet, a fluidized medium inlet, a solid material inlet, and a total outlet. Calcium oxide particles enter the fluidized bed reactor through the solid material inlet. The water inlet is used to introduce water vapor or water mist into the fluidized bed reactor. In the fluidized bed reactor, calcium oxide reacts with water to produce calcium hydroxide, releasing chemical energy as heat. The total outlet of the fluidized bed reactor is connected to the inlet of the gas-solid separator, conveying the heat-carrying calcium hydroxide particles and fluidizing medium to the gas-solid separator. After gas-solid separation, the solid outlet of the gas-solid separator is connected to the inlet of the energy-releasing unit, conveying the solid material (mainly calcium oxide particles) to the calcium hydroxide storage tank of the energy-releasing unit. The gas outlet of the gas-solid separator is connected to the high-temperature gas inlet of the heat exchanger, transferring the heat in the fluidizing medium to the external heat exchange medium through the heat exchanger. Taking water as the heat exchange medium as an example, after heat extraction and heat exchange, high-temperature steam of about 400°C can be formed, which can be used to provide heat to industrial activities, residential life, and other scenarios requiring heating. The high-temperature gas outlet of the heat exchanger is connected to the fluidizing medium inlet of the fluidized bed reactor via a centrifugal fan, allowing the cooled fluidizing medium to re-enter the fluidized bed reactor. Preferably, the fluidizing medium in the energy release system is at least one of nitrogen, carbon dioxide, and a conventional inert gas.

[0151] Taking the energy release system using a fixed-bed reactor as an example, as shown in Figure 7, the fixed-bed reactor has a water inlet, a solid material inlet, and a total outlet. A heat exchange pipeline is installed inside the fixed-bed reactor. Calcium oxide particles enter the fixed-bed reactor from the solid material inlet. The water inlet is used to introduce water vapor or water mist into the fixed-bed reactor. The total outlet is connected to the inlet of the energy release unit, which transports the solid material (mainly calcium oxide particles) to the calcium hydroxide storage tank of the energy release unit.

[0152] In a fixed-bed reactor, calcium oxide particles come into contact with heat exchange pipes. The calcium oxide reacts with water to produce calcium hydroxide, releasing chemical energy as heat. This heat is then transferred to the heat exchange medium within the pipes. Water is the preferred heat exchange medium, which, after heat exchange, generates high-temperature steam at approximately 400°C, providing heat for industrial activities, residential use, and other applications requiring heating. After sufficient reaction and heat release, the calcium hydroxide produced in the fixed-bed reactor is transported through the main outlet to the calcium hydroxide storage tank of the energy-releasing unit.

[0153] Correspondingly, the fixed-bed reactor can also employ a shell-and-tube heat exchanger, where the tube side can be considered as the heat exchange pipeline and the shell side as the reaction space between the calcium oxide particles and water. Furthermore, intermittent operation is preferred in the fixed-bed reactor. After a batch of calcium oxide particles is filled into the fixed-bed reactor, water is injected to initiate a reaction-exothermic-heat exchange process. By controlling the water inflow, the material in the fixed-bed reactor is always predominantly solid calcium-based material. After sufficient heat exchange, all the calcium-based material is discharged from the fixed-bed reactor, and then new calcium oxide particles and water are added to the fixed-bed reactor for a new round of reaction-exothermic-heat exchange.

[0154] In addition to storing the calcium hydroxide particles formed after the release of chemical energy, the energy-releasing unit also has a certain temperature in practical applications. The solid material discharged by the energy-releasing system (mainly calcium hydroxide particles) still has a certain temperature. The calcium hydroxide storage tank of the energy-releasing unit has at least an insulation jacket to reduce heat loss and store this part of the high-temperature sensible heat.

[0155] The thermochemical thermal energy storage system in this embodiment can thermochemically store high-temperature waste heat generated in industrial activities, minimizing the waste of industrial thermal energy. It can also utilize the peak shaving and valley filling effect of electricity to make the best and most effective use of electricity, increase the proportion of electricity used in industrial activities, reduce the dispersed and inefficient use of fossil fuels, and greatly reduce carbon emissions and air pollutant emissions.

[0156] Example 4

[0157] This embodiment, based on embodiment 3, describes the treatment of water vapor as shown in Figure 5.

[0158] The thermochemical thermal energy storage system also includes an H2O unit, which mainly serves as a water recycling system. The inlet of the H2O unit is connected to the gaseous material outlet of the energy storage system to recover the high-temperature water vapor generated by decomposition in the energy storage system. The outlet of the H2O unit is connected to the water inlet of the energy release system to provide steam to the energy release system for the exothermic reaction of calcium oxide particles. Thus, the H2O unit enables the water medium in the entire thermochemical thermal energy storage system to be recycled, reducing water waste. At the same time, it can also recover the high-temperature heat carried by the water medium, reducing the waste of industrial thermal energy.

[0159] The H2O unit includes at least a steam accumulator; the inlet of the steam accumulator is connected to the gaseous material outlet of the energy storage system through a compressor, and the high-temperature water vapor generated in the energy storage system is compressed into liquid water for storage through the compressor; the outlet of the steam accumulator is connected to the water inlet of the energy release system through an expansion valve, and since the liquid water in the steam accumulator has a certain temperature and pressure, it can be vaporized through the expansion valve to form water vapor, which is used to directly provide steam to the energy release system.

[0160] Example 5

[0161] This embodiment proposes another H2O unit, as shown in Figure 8. The H2O unit includes a preheating recovery system, which comprises at least three stages of heat exchange devices, sequentially designated as the first, second, and third heat exchange devices. This allows the high-temperature steam (approximately 500°C) generated in the energy storage system to pass through at least three stages of heat exchange, fully recovering the heat carried by the steam discharged from the energy storage system and reducing industrial heat energy waste. The high-temperature heat exchange medium in the entire preheating recovery system refers to the steam discharged from the energy storage system; the low-temperature heat exchange medium in the first stage heat exchange device is steam at approximately 400°C, the low-temperature heat exchange medium in the second stage heat exchange device is steam at approximately 200°C, and the low-temperature heat exchange medium in the third stage heat exchange device is water at approximately 70°C. The high-temperature heat exchange medium in the preheating recovery system, after heat exchange, can be directly discarded and discharged, or it can be supplied to the energy release system as needed.

[0162] Furthermore, this embodiment combines the preheating recovery system with the technical solution in Embodiment 4. Based on Embodiment 4, the preheating recovery system is set between the energy storage system and the compressor. That is, the inlet of the preheating recovery system is directly connected to the gaseous material outlet of the energy storage system, and the outlet of the preheating recovery system is connected to the compressor. This allows the high-temperature steam of about 500°C generated in the energy storage system to be preheated and recovered first, and then compressed into liquid water by the compressor and stored in the steam accumulator. This not only fully recovers the high-temperature heat carried by the water medium and reduces the waste of industrial heat energy, but also reduces the workload of the compressor.

[0163] Example 6

[0164] Based on the energy storage system of any one of the embodiments 3-5, this embodiment proposes a thermochemical thermal energy storage method. The thermochemical energy storage system is Ca(OH)2 / CaO, and energy is stored through the interconversion between thermal energy and chemical energy. It is divided into an energy storage stage and an energy release stage.

[0165] During the energy storage phase, the calcium hydroxide particles stored in the energy release unit are transported to the energy storage system. In the energy storage system, industrial waste heat or electricity is used to heat the calcium hydroxide particles and cause them to decompose. The water generated by the decomposition is stored in the H2O unit, and the calcium oxide particles generated by the decomposition are transported to the energy storage unit for storage.

[0166] During the energy release phase, when energy needs to be provided to the outside world, water vapor or water mist is supplied to the energy release system. Simultaneously, calcium oxide particles are supplied to the energy release system through the energy storage unit. The calcium oxide particles react with water to release heat, which is then provided to the outside world. The calcium hydroxide particles generated from the reaction are transported to the energy release unit for storage. Although specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and various changes or modifications can be made to these embodiments without departing from the principles and essence of the present invention. Therefore, the scope of protection of the present invention is defined by the appended claims.

Claims

1. A thermo-chemical heat storage and energy supply system, characterized in that, The heating system includes a first steam buffer tank (9) and a thermochemical heat storage device. The thermochemical heat storage device includes a decomposition reactor (1), a first silo (6), a synthesis reactor (11), and a second silo (15) connected in sequence. The thermochemical heat storage device is equipped with calcium-based materials that can be circulated and transported. The decomposition reactor (1) is equipped with an energy supply device (2). The circulation pipe (93) of the first steam buffer tank (9) is connected to the synthesis reactor (11), which can transport a portion of the steam in the first steam buffer tank (9) to the synthesis reactor (11). The inlet of the first steam buffer tank (9) is connected to the decomposition reactor (1) through a first steam pipeline (5). The inlet of the first steam buffer tank (9) is connected to the synthesis reactor (11) through a second steam pipeline (14), or the steam produced by the synthesis reactor (11) is discharged through the second steam pipeline (14).

2. A thermo-chemical heat storage and energy supply system, characterized in that, The heating system includes a first steam buffer tank (9) and a thermochemical heat storage device. The thermochemical heat storage device includes a decomposition reactor (1), a first silo (6), a synthesis reactor (11), and a second silo (15) connected in sequence. The thermochemical heat storage device contains calcium-based materials that can be circulated and transported. The decomposition reactor (1) is equipped with an energy supply device (2). The first steam buffer tank (9) has a steam supply pipeline (91). The first steam buffer tank (9) is connected to the steam consumption system (92) through the steam supply pipeline (91). The first steam buffer tank (9) is connected to the synthesis reactor (11) via a circulation pipe (93), which can transport a portion of the steam in the first steam buffer tank (9) to the synthesis reactor (11); the inlet of the first steam buffer tank (9) is connected to the decomposition reactor (1) via a first steam pipeline (5); the inlet of the first steam buffer tank (9) is connected to the synthesis reactor (11) via a second steam pipeline (14), or the steam produced by the synthesis reactor (11) is discharged through the second steam pipeline (14).

3. A thermo-chemical heat accumulating energy storage heating system according to claim 1 or 2, characterized in that, The heating system includes a water supply unit, which includes a water supply source (19), a softened water tank (21), a heat exchanger (23), and a water storage tank (25) connected in sequence. The softened water tank (21) is provided with a first water pipe (22), which is connected to the low-temperature medium flow channel of the heat exchanger (23). The first steam pipe (5) is connected to the high-temperature medium flow channel of the heat exchanger (23).

4. - Thermally-chemical heat accumulation energy storage heating system according to at least one of the preceding claims, characterized in that, The synthesis reactor (11) is equipped with a heat exchange device (27), the outlet of the water storage tank (25) is connected to the inlet of the heat exchange device (27), and the outlet of the heat exchange device (27) is connected to the first steam buffer tank (9).

5. - Thermally-chemical heat accumulation energy storage heating system according to at least one of the preceding claims, characterized in that, A steam ejector (28) is provided at the outlet of the second steam pipeline (14) or heat exchanger (27). The outlets of the second steam pipeline (14) and heat exchanger (27) are connected to the inlet of the steam ejector (28). The outlet of the steam ejector (28) is connected to the first steam buffer tank (9).

6. - Thermally-chemical heat accumulation energy storage heating system according to at least one of the preceding claims, characterized in that, The heating system includes a steam replenishment unit, which includes a steam generator (31) and a second steam buffer tank (32) connected in sequence. The inlet of the steam generator (31) is connected to the softened water tank (21) through a second water pipe (29). The steam outlet of the steam generator (31) is connected to the inlet of the second steam buffer tank (32). The outlet of the second steam buffer tank (32) is provided with a heat replenishment pipe (33), which is connected to the first steam buffer tank (9).

7. - Thermally-chemical heat accumulation energy storage heating system according to at least one of the preceding claims, characterized in that, The outlet of the second steam buffer tank (32) is provided with a reaction steam supply pipe (34), which is connected to the synthesis reactor (11).

8. - Thermally-chemical heat accumulation energy storage heating system according to at least one of the preceding claims, characterized in that, The first silo (6) is provided with a first feeding device (7) at its outlet, and the second silo (15) is provided with a second feeding device (16) at its outlet. The first feeding device (7) is connected to the synthesis reactor (11), and the second feeding device (16) is connected to the decomposition reactor (1).

9. - Thermally-chemical heat accumulation energy storage heating system according to at least one of the preceding claims, characterized in that, The outlet of the second steam buffer tank (32) is provided with a first material-carrying steam pipe (35), the outlet of the first feeding device (7) is provided with a first feeding pipe (8), the synthesis reactor (11) is provided with a first feeding pipeline (10), the first material-carrying steam pipe (35) or the first feeding pipe (8) is provided with a first throttling device (36), the first material-carrying steam pipe (35) and the first feeding pipe (8) are respectively connected to the inlet of the first throttling device (36), and the outlet of the first throttling device (36) is connected to the first feeding pipeline (10); The outlet of the second steam buffer tank (32) is provided with a second material loading steam pipe (37), the outlet of the second feeding device (16) is provided with a second feeding pipe (17), the decomposition reactor (1) is provided with a second feeding pipeline (18), the second material loading steam pipe (37) or the second feeding pipe (17) is provided with a second throttling device (38), the second material loading steam pipe (37) and the second feeding pipe (17) are respectively connected to the inlet of the second throttling device (38), and the outlet of the second throttling device (38) is connected to the second feeding pipeline (18).

10. - Thermally-chemical heat accumulation energy storage heating system according to at least one of the preceding claims, characterized in that, The discharge port of the decomposition reactor (1) is provided with a first discharge pipe (3), the first discharge pipe (3) is connected to the inlet of the first gas-solid separation device (4), the steam outlet of the first gas-solid separation device (4) is connected to the first steam pipe (5), and the calcium-based material outlet of the first gas-solid separation device (4) is connected to the inlet of the first silo (6). The outlet of the synthesis reactor (11) is provided with a second discharge pipe (12), which is connected to the inlet of the second gas-solid separation device (13). The steam outlet of the second gas-solid separation device (13) is connected to the second steam pipe (14), and the calcium-based material outlet of the second gas-solid separation device (13) is connected to the inlet of the second silo (15).

11. A thermo-chemical heat storage energy supply heating method, characterized by, The heating method is applied to the thermochemical thermal energy storage heating system according to any one of claims 1-10, and the heating method includes an energy storage heating process and an energy release heating process; The energy storage and heating process transports the calcium hydroxide stored in the second silo (15) to the decomposition reactor (1), where the calcium hydroxide is heated and decomposed by the energy supply device (2), and the resulting calcium oxide is transported to the first silo (6) for storage. The generated superheated steam is transported to the first steam buffer tank (9) for supplying steam to the steam-using system (92); The energy release and heat supply process transports the calcium oxide stored in the first silo (6) to the synthesis reactor (11) and supplies steam into the synthesis reactor (11). The calcium oxide in the synthesis reactor (11) reacts with water to release heat and the heat is transported to the first steam buffer tank (9) in the form of superheated steam to supply steam to the steam system (92). The generated calcium hydroxide is transported to the second silo (15) for storage.

12. A thermo-chemical heat storage energy storage system, characterized in that, The energy storage system comprises an energy storage system, an energy storage unit, an energy release system, and an energy release unit connected sequentially. In the energy storage system, solid materials can be circulated and transported. These solid materials include high-chemical-energy materials and low-chemical-energy materials. Following the transport sequence of the solid materials, in the energy storage system, low-chemical-energy materials react with heat to generate high-chemical-energy materials, achieving chemical thermal energy storage. The energy storage unit stores the generated high-chemical-energy materials. In the energy release system, high-chemical-energy materials react to generate low-chemical-energy materials, releasing chemical energy as heat. The energy release unit stores the generated low-chemical-energy materials.

13. The thermo-chemical heat storage system of claim 12, wherein, The energy storage system has a heater for heating solid materials.

14. A thermo-chemical heat accumulation energy storage system according to at least one of the claims 12-13, characterized in that, The solid material is a calcium-based energy storage system.

15. A thermo-chemical heat accumulation energy storage system according to at least one of the claims 12-14, characterized in that, High-chemical-energy materials include calcium oxide particles, while low-chemical-energy materials include calcium hydroxide particles.

16. A thermo-chemical heat storage energy storage method, characterized by, The energy storage method is applied to the thermochemical thermal energy storage system according to any one of claims 12-15. The energy storage method adopts a thermochemical energy storage system of Ca(OH)2 / CaO and stores energy through the mutual conversion between thermal energy and chemical energy. The energy storage method includes an energy storage stage and an energy release stage.

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