Thermochemical energy storage system and energy storage method with double revolving beds cooperating with calcium circulation
By using a dual-rotating-bed synergistic calcium circulation system, the independently operating calcination and carbonation reactors, combined with a gas-solid heat exchanger and turbine, solve the problems of difficult coupling of heat absorption and release processes and low heat utilization in traditional calcium circulation energy storage systems. This achieves efficient energy storage and release, improves system thermal efficiency and stability, and is suitable for the efficient utilization of renewable energy and industrial waste heat.
Patent Information
- Application Number
- CN202511737338.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-25
- Publication Date
- 2026-01-20
AI Technical Summary
Traditional calcium cycle energy storage systems suffer from difficult heat absorption and release processes, low heat utilization, inability to achieve continuous energy supply, and high equipment thermal stress, failing to meet the needs of large-scale grid connection of renewable energy and efficient recovery of industrial waste heat.
The system employs a dual-rotating-bed synergistic calcium circulation system, which operates independently through a calcination reactor and a carbonation reactor, combined with a gas-solid heat exchanger and a turbine, to achieve a continuous process of CaCO3 decomposition energy storage and CaO carbonation energy release. The system utilizes high-temperature exhaust gas to preheat materials and generates electricity through a turbine, thus achieving efficient heat utilization.
It achieves continuous energy storage and release, improves heat utilization, ensures stable system operation, enhances thermal efficiency, enables all-weather power generation, solves the thermal stress problem of traditional systems, and has the advantages of high energy storage density and no environmental pollution.
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Figure CN121363885A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of thermochemical energy storage, and more particularly relates to a thermochemical energy storage system and method with a double-rotary bed and calcium cycle. BACKGROUND
[0002] Current thermochemical energy storage technologies mainly include metal oxide cycles, ammonia decomposition cycles, and methane reforming cycles. The calcium cycle (CaO / CaCO3 cycle) has the characteristics of strong adaptability, easy availability of raw materials, and environmental friendliness. The core principle of the calcium cycle is to store and release energy based on the reversible reaction of CaO and CO2.
[0003] Although the calcium cycle technology has significant potential, traditional reactors (such as fixed beds, fluidized beds, and single-rotary beds) need to alternately perform "decomposition energy storage" and "carbonation energy release", which requires frequent temperature switching (400-950℃), resulting in high thermal stress on the equipment and the inability to achieve continuous energy supply. If a double-reactor (decomposition furnace + carbonation furnace) is used, an additional CO2 delivery and heat exchange system needs to be designed, which results in heat loss (thermal efficiency of only 55%-65%). Therefore, the existing technology has the core problems of difficulty in coupling the heat absorption and release processes and low heat utilization rate. Therefore, under the dual demands of large-scale grid connection of renewable energy and efficient recovery of industrial waste heat, the technical bottlenecks of traditional calcium cycle energy storage systems cannot meet the requirements of practical applications, and there is an urgent need for a thermochemical energy storage system that can solve the above problems. SUMMARY
[0004] In view of the above defects or improvement needs of the prior art, the present application provides a thermochemical energy storage system and method with a double-rotary bed and calcium cycle, which solves the problems of difficulty in coupling the heat absorption and release processes and low heat utilization rate.
[0005] To achieve the above-mentioned purpose, according to one aspect of the present application, a thermochemical energy storage system with a double-rotary bed and calcium cycle is provided, which comprises a calcination reactor, a carbonation reactor, a CO2 storage tank, a CaCO3 storage tank, and a CaO storage tank, wherein: The outlet end of the calcination reactor is connected to the CO2 storage tank and the CaO storage tank, a first gas-solid heat exchanger is arranged between the CO2 storage tank and the calcination reactor, and the CaCO3 storage tank is connected to the calcination reactor through the first gas-solid heat exchanger. The inlet end of the carbonation reactor is connected to the CaO storage tank and the CO2 storage tank, a second gas-solid heat exchanger is arranged between the carbonation reactor and the CO2 storage tank, and the outlet end of the carbonation reactor is connected to the CaCO3 storage tank through the second gas-solid heat exchanger.
[0006] Further preferably, the system further comprises a first turbine arranged between the CO2 storage tank and the second gas-solid heat exchanger.
[0007] Further preferably, the system further comprises a second turbine connected to the outlet end of the carbonation reactor.
[0008] Further preferably, the system further comprises a first compressor arranged between the first gas-solid heat exchanger and the CO2 storage tank.
[0009] Further preferably, the system further comprises a second compressor arranged between the carbonation reactor and the second gas-solid heat exchanger.
[0010] Further preferably, the first turbine, the second compressor and the second gas-solid heat exchanger are connected by a first three-way valve.
[0011] Further preferably, the outlet end of the calcination reactor is provided with a first cyclone separator, one end of which is connected to the first gas-solid heat exchanger and the other end of which is connected to the CaO storage tank.
[0012] Further preferably, the outlet end of the carbonation reactor is provided with a second cyclone separator, one end of which is connected to the second gas-solid heat exchanger and the other end of which is connected to the second compressor and the second turbine.
[0013] Further preferably, the second turbine, the second compressor and the second cyclone separator are connected by a second three-way valve.
[0014] According to another aspect of the present application, there is provided an energy storage method of the above-mentioned double-rotation-bed coordinated calcium cycle reaction thermal chemical energy storage system, which comprises a night mode, a day mode and a coordination mode, wherein: In the night mode, the calcination reactor, the first cyclone separator, the first gas-solid heat exchanger and the first compressor are stopped, the CO2 storage tank and the CaO storage tank respectively deliver CO2 and CaO to the carbonation reactor, CO2 and CaO in the carbonation reactor react to generate CaCO3 which is stored in the CaCO3 storage tank, and the unreacted CO2 in the carbonation reactor is partly sent into the second turbine to generate electricity and partly sent into the second gas-solid heat exchanger through the second compressor to exchange heat with CaCO3 in the second gas-solid heat exchanger, thereby realizing the carbonation energy release of CaO. In the daytime mode, the carbonation reactor, the second cyclone separator, the second gas-solid heat exchanger, the second compressor and the second turbine stop working, the CaCO3 storage tank stores CaCO3 transported into the calcination reactor to be decomposed into CO2 and CaO, and the CO2 and CaO are stored in the CO2 storage tank and the CaO storage tank respectively, and the CO2 in the CO2 storage tank enters the first turbine for power generation, thereby realizing the decomposition of CaCO3 and energy storage; In the cooperative mode, CaCO3 in the CaCO3 storage tank is transported to the calcination reactor, the CaCO3 is decomposed in the calcination reactor, the products of the decomposition reaction are separated by the first cyclone separator to obtain high-temperature CaO and CO2, part of the high-temperature CaO is stored in the CaO storage tank, and the other part is sent to the carbonation reactor; the high-temperature CO2 is preheated by the first gas-solid heat exchanger after the CaCO3 from the carbonation reactor, and then enters the first compressor for pressurization, and after pressurization, enters the first turbine for power generation; the CO2 after power generation is mixed with part of the CO2 from the carbonation reactor, preheated by the second gas-solid heat exchanger, and finally enters the carbonation reactor; the CO2 entering the carbonation reactor reacts with CaO to generate high-temperature CaCO3, and the generated CaCO3 enters the CaCO3 storage tank through the second gas-solid reactor; the unreacted CO2 enters the first turbine for power generation after being compressed, and the other part is sent to the second turbine for power generation.
[0015] Overall, compared with the prior art, the above technical scheme conceived by the present application has the following beneficial effects: 1. The present application adopts a calcination reactor and a carbonation reactor, which are independently operated and cooperatively coupled, realizes that the decomposition of CaCO3 for energy storage and the carbonation of CaO for energy release are respectively placed in two independent rotary beds, realizes the continuous storage and release of energy through the closed-loop transportation of CaO / CaCO3 particles, avoids the disadvantages of frequent switching of traditional single beds, decouples the heat absorption and release processes, has high heat utilization rate, and is stable and continuous in operation.
[0016] 2. In the present application, the first gas-solid heat exchanger and the second gas-solid heat exchanger are arranged, the high-temperature tail gas of the calcination reactor is used to preheat the CaCO3 entering the calcination bed, and the high-temperature CaCO3 generated in the heat release process of the carbonation bed is used to heat the CO2 entering the carbonation bed, so as to realize efficient heat utilization, strengthen the cooperative utilization of heat, and greatly improve the system thermal efficiency.
[0017] 3. In the present application, the first turbine and the second turbine are arranged, the energy of high-temperature CO2 is converted into mechanical energy to drive the subsequent generator to generate electricity, so as to achieve the purpose of utilizing the stored energy.
[0018] 4. The present application stores the calcium oxide particles obtained by calcination of the calcination reactor to improve the mismatch between supply and demand in the energy market by setting a calcium oxide storage bin; stores the heat carrier CaCO3 particles that release heat in certain cases to be transported back to the calcination reactor for regeneration of calcium oxide, achieving balance of material flow in the system, using renewable energy solar heat / industrial waste heat instead of fuel to provide energy for the calcination reaction of CaCO3, and then storing it in the form of chemical energy, with the advantages of long storage time, high energy storage density, no environmental pollution, etc. During the peak period of energy demand, the chemical energy is converted back into heat energy to reuse the turbine for power generation.
[0019] 5. The present application adopts two different operation modes, day and night, in the night mode, the rotary light-thermal calcination reactor stops working, and the CaCO3 produced by the rotary carbonation reactor is stored in the carbonic acid storage bin; in the daytime mode, the rotary light-thermal calcination reactor works normally, and the calcination of CaCO3 produced by the rotary carbonation reactor in daytime operation and CaCO3 produced in nighttime operation and stored in the CaCO3 storage bin and the regeneration of calcium oxide are realized. It can make full use of solar energy to realize all-weather uninterrupted power generation, so that its energy supply is not limited to daytime. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 is a structural schematic diagram of a double-rotary-bed cooperative calcium cycle reaction thermochemical energy storage system constructed according to the preferred embodiment of the present application.
[0021] In all the drawings, the same reference signs are used to represent the same elements or structures, wherein: 1 - calcination reactor, 2 - first cyclone separator, 3 - first gas-solid heat exchanger, 4 - first compressor, 5 - CO2 storage tank, 6 - first turbine, 7 - CaCO3 storage tank, 8 - first three-way valve, 9 - second gas-solid heat exchanger, 10 - second compressor, 12 - second cyclone separator, 13 - carbonation reactor, 14 - second turbine, 15 - CaO storage tank, 16 - second three-way valve. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.
[0023] A kind of double-rotation bed cooperates with calcium cycle's thermochemical energy storage system and energy storage method, the system includes negative pressure rotary negative pressure calcination reactor 1, rotary carbonation reactor 13, first cyclone 2 and second cyclone 12, first gas-solid heat exchanger 3 and second gas-solid heat exchanger 9, first CO 2 compressor 4 and second compressor 10, first three-way valve 16 and second three-way valve 8, first turbine 6 and second turbine 14, CO 2 storage tank 5, CaO storage tank 15 and CaCO 3 storage tank 7.The heat source of calcination reactor 1 is solar energy, wherein solar energy is converged into calcination reactor by condenser array, and constant temperature heating area is manufactured by steel sodium heat pipe technology.Calcination reactor 1 sends in material rate 30kg / h, working temperature is 900 DEG C, rotation speed is set to 10rpm, inclination angle is 1 DEG, and the generated CaO and CO 2 are separated by first cyclone 2, and the first cyclone is single-tube tangential inlet cyclone separator.CO 2 is pumped out to realize negative pressure environment in reactor 1, wherein vacuum pump is high-temperature resistant repeated piston vacuum pump, and CaO is stored in CaO storage tank 15, and CaO storage tank 15 and CaCO 3 storage tank 7 are vertical conical solid storage tanks.The high-temperature CO 2 extracted is heated by first gas-solid heat exchanger 3 to heat CaCO 3 sent from CaCO 3 storage tank 7 to calcination reactor 1, wherein the first gas-solid heat exchanger 3 is plate heat exchanger.CaCO 3 particles sent into calcination reactor 1 are used as initial material.CO 2 used for preheating CaCO 3 is compressed by first compressor 4 and sent into high-pressure CO 2 storage tank 5, wherein the compressor is reciprocating piston compressor.High-pressure CO 2 in CO 2 storage tank 5 can be directly used to generate power by turbine 6, and the turbine is preferably single-stage radial turbine.Carbonation reactor 13 sends in material rate 16.8kg / h, working temperature is 750 DEG C, rotation speed is set to 8rpm, inclination angle is 1 DEG, and consumes CaO and part of CO 2, and the remaining CO 2 and generated CaCO 3 are separated by second cyclone 12, and part of CO 2 is sent into second compressor 10 for compression and then combined with CO 2 after work, and another part of CO 2 is sent to second turbine 14 for work to generate power and then sent back to carbonation reactor 13.The combined CO 2 is preheated by high-temperature CaCO 3 generated in carbonation reactor 13 by second gas-solid heat exchanger 9 and then sent into carbonation reactor 13.According to second three-way valve 16, the volume flow rate of CO 2 sent from carbonation reactor 13 for work accounts for 1 / 2.
[0024] The selection of first cyclone 2 is preferably single-tube tangential inlet cyclone separator, but high-temperature resistant material is selected, preferably Inconel625 alloy, in addition, bypass type cyclone separator can also meet the requirements.
[0025] CaO storage tank 15 and CaCO3 storage tank 7 are preferably vertical, and can also be horizontal, the bottom is conical to facilitate the material out, the material is selected from stainless steel.
[0026] The first gas-solid heat exchanger is preferably a plate heat exchanger, and can also be a tubular heat exchanger. The first compressor 4 is preferably a reciprocating piston compressor, which can also be a screw CO2 compressor, and the CO2 storage tank 5 is selected from a stainless steel cylindrical storage tank, which can also be a spherical storage tank.
[0027] The first turbine 6 is preferably a multi-stage axial turbine, which can also be a single-stage radial turbine, which is simple in structure and low in cost, and is more suitable for industrial waste heat utilization.
[0028] The working mode of the energy storage system of the application will be introduced below, as follows: Night mode: calcination reactor 1, first cyclone separator 2, first gas-solid heat exchanger 3, first compressor 4 stop working, high-temperature CO2 in CO2 storage tank 5 is first converted into mechanical energy by first turbine 6, and then the low-temperature CO2 and CaO storage tank 15 are respectively transported to the carbonation reactor 13 to generate high-temperature CaCO3, and the carbonation reactor is completed. The start of the night mode. After stable operation, the high-temperature CaCO3 generated in the carbonation reactor process and the excess CO2 heated in the reactor are separated by the second cyclone separator, wherein the high-temperature CaCO3 is used to preheat the CO2 entering the carbonation reactor and is sent back to the CaCO3 storage tank, and a part of the CO2 is sent into the second turbine 13 to generate electricity and then is sent back to the carbonation reactor, and another part is pressurized by the second compressor and combined with the CO2 from the first turbine to be heated by the second gas-solid heat exchanger, thereby realizing the carbonation of CaO. Day mode: carbonation reactor 13, second cyclone separator 12, second gas-solid heat exchanger 9, second compressor 10 and second turbine 14 stop working, CaCO3 in CaCO3 storage tank is transported to the calcination reactor to be decomposed into CO2 and CaO under the heating of solar energy / waste heat to complete the start. When stable operation, the generated CaO is sent to the CaO storage tank for storage, and the CO2 is preheated by the first gas-solid heat exchanger to transport the CaCO3 to the calcination reactor, and then is pressurized by the first compressor and sent to the CO2 storage tank for storage. The excess CO2 in the CO2 storage tank enters the first turbine for power generation, thereby realizing the decomposition of CaCO3.
[0029] Synergy: The synergy operation mode refers to the system simultaneously completing the energy storage and release processes. The specific operation process is as follows: CaCO3 in the CaCO3 storage tank 7 is transported to the calcination reactor and the decomposition reaction is completed under the heating of solar energy / industrial waste heat. High-temperature CaO and CO2 are separated out through the first cyclone separator 3. Part of the high-temperature CaO is sent to the CaO storage tank 15 for storage, and the other part is directly sent to the carbonation reactor 13. High-temperature CO2 is preheated by the first gas-solid heat exchanger 3, sent to the first compressor 4 after being preheated by the CaCO3 in the second gas-solid heat exchanger 9, pressurized, and sent to the first turbine 6 to generate electricity. The CO2 after being used for heating is mixed with part of the CO2 from the carbonation reactor 13, preheated by the second gas-solid heat exchanger 9, and finally sent to the carbonation reactor 13. The CO2 in the carbonation reactor 13 reacts with CaO to generate high-temperature CaCO3 and heat the CO2. The high-temperature CaCO3 is sent to the calcination reactor 1 after passing through the second gas-solid heat exchanger 9 and the first gas-solid heat exchanger 3. Part of the CO2 is mixed with the CO2 after being used by the first turbine 6, and the other part is sent to the second turbine 14 to do work and then sent back to the carbonation reactor 13. This mode has no storage, which leads to energy consumption, and at the same time, the energy storage and release are realized, thereby improving the total thermal efficiency of the system.
[0030] The present application realizes the storage of solar energy / industrial waste heat, which is taken out to generate electricity when needed.
[0031] Those skilled in the art will easily understand that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A thermo-chemical energy storage system with a dual rotary bed coupled with a calcium cycle, characterized in that, The system comprises a calcination reactor (1), a carbonation reactor (13), a CO2 storage tank (5), a CaCO3 storage tank (7) and a CaO storage tank (15), wherein: The outlet end of the calcination reactor (1) is connected with the CO2 storage tank (5) and the CaO storage tank (15), and a first gas-solid heat exchanger (3) is arranged between the CO2 storage tank (5) and the calcination reactor (1), and the CaCO3 storage tank (7) is connected with the calcination reactor (1) through the first gas-solid heat exchanger (3); The inlet end of the carbonation reactor (13) is connected with the CaO storage tank (15) and the CO2 storage tank (5) at the same time, a second gas-solid heat exchanger (7) is arranged between the carbonation reactor (13) and the CO2 storage tank (5), and the outlet end of the carbonation reactor (13) is connected with the CaCO3 storage tank (7) through the second gas-solid heat exchanger (7).
2. A thermo-chemical energy storage system with a dual-rotation bed and calcium looping according to claim 1, characterized in that, The system further comprises a first turbine (6) arranged between the CO2 storage tank (5) and the second gas-solid heat exchanger (9).
3. A thermo-chemical energy storage system with a dual-rotation bed in cooperation with calcium cycle according to claim 2, characterized in that, The system further comprises a second turbine (14) connected with the outlet end of the carbonation reactor (13).
4. A thermo-chemical energy storage system with a dual-rotation bed in cooperation with calcium cycle according to claim 3, characterized in that, The system further comprises a first compressor (4) arranged between the first gas-solid heat exchanger (3) and the CO2 storage tank (5).
5. A thermo-chemical energy storage system with a dual-rotation bed in cooperation with calcium cycle according to claim 4, characterized in that, The system further comprises a second compressor (10) arranged between the carbonation reactor (13) and the second gas-solid heat exchanger (9).
6. A thermo-chemical energy storage system with a dual-rotation bed in cooperation with calcium cycle according to claim 5, characterized in that, The first turbine (6), the second compressor (10) and the second gas-solid heat exchanger (9) are connected through a first three-way valve (8).
7. A thermo-chemical energy storage system with a dual-rotation bed in cooperation with calcium cycle according to claim 6, characterized in that, The outlet end of the calcination reactor (1) is provided with a first cyclone separator (12), one end of which is connected with the first gas-solid heat exchanger (3) and the other end of which is connected with the CaO storage tank (15).
8. A thermo-chemical energy storage system with a dual-rotation bed in cooperation with calcium cycle according to claim 7, characterized in that, The outlet end of the carbonation reactor (13) is provided with a second cyclone separator (12), one end of which is connected with the second gas-solid heat exchanger (9) and the other end of which is connected with the second compressor (10) and the second turbine (14).
9. A thermo-chemical energy storage system with a dual-rotation bed in cooperation with calcium cycle according to claim 8, characterized in that, The second turbine (14), the second compressor (10) and the second cyclone separator (12) are connected through a second three-way valve (16).
10. A method of energy storage of a thermo-chemical energy storage system with a double-rotation bed in cooperation with a calcium cycle reaction according to any one of claims 1 to 9, characterized in that, The energy storage method comprises a night mode, a daytime mode and a cooperation mode, wherein: In the night mode, the calcination reactor (1), the first cyclone (2), the first gas-solid heat exchanger (3), the first compressor (4) stop working, the CO2 storage tank (5) and the CaO storage tank (15) respectively deliver CO2 and CaO to the carbonation reactor (13), in which CO2 and CaO react to generate and store in the CaCO3 storage tank (7), the unreacted CO2 in the carbonation reactor enters the second turbine (14) to generate electricity, and a part of it enters the second gas-solid heat exchanger (9) to exchange heat with CaCO3 in the second gas-solid heat exchanger (9), thereby realizing the carbonation energy release of CaO; In the day mode, the carbonation reactor (13), the second cyclone (12), the second gas-solid heat exchanger (9), the second compressor (10) and the second turbine (14) stop working, the CaCO3 storage tank (7) delivers CaCO3 to the calcination reactor (1) to decompose into CO2 and CaO, and store in the CO2 storage tank (5) and the CaO storage tank (15) respectively, the CO2 in the CO2 storage tank (5) enters the first turbine (6) for power generation, thereby realizing the decomposition of CaCO3 energy storage; In the cooperation mode, the CaCO3 storage tank (7) delivers CaCO3 to the calcination reactor (1), which decomposes in the calcination reactor (1), and the products of the decomposition reaction are separated by the first cyclone (3) to obtain high-temperature CaO and CO2, wherein a part of the high-temperature CaO is stored in the CaO storage tank (15), and the other part is sent to the carbonation reactor (13); the high-temperature CO2 is preheated by the first gas-solid heat exchanger (3) to the CaCO3 from the carbonation reactor (13), and then enters the first compressor (4) to be pressurized, and after being pressurized, it is sent to the first turbine (6) to generate electricity; the CO2 after power generation is mixed with part of the CO2 from the carbonation reactor (13) to preheat in the second gas-solid heat exchanger (9), and finally enters the carbonation reactor (13); the CO2 entering the carbonation reactor (13) reacts with CaO to generate high-temperature CaCO3, which enters the CaCO3 storage tank (7) through the second gas-solid reactor (9); the unreacted CO2 enters the first turbine (6) after being compressed to generate electricity, and the other part is sent to the second turbine (14) to generate electricity.