CN-116220851-B - Energy storage system based on thermochemical energy storage and Brayton cycle and operation method

Abstract

The invention relates to the technical field of energy storage, and provides an energy storage system based on thermochemical energy storage and Brayton cycle and an operation method. The energy storage system includes a storage device and an energy storage device. The energy storage equipment comprises a calcium hydroxide calcination reactor, a first heat exchange network, a first heat regenerator, a first compressor, a first turbine, a first motor and a first generator, and all the structural components are connected in sequence. The high-temperature and high-pressure carbon dioxide heats the calcium hydroxide solid particles, so that the calcium hydroxide is decomposed into calcium oxide solid particles and water vapor, and the heat energy is converted into chemical energy. The energy storage system provided by the invention is used as an energy comprehensive storage platform, realizes conversion, transmission and storage of electric energy, heat energy and chemical energy, has high energy conversion efficiency, and can provide cold and hot electricity comprehensive energy service for end users.

Inventors

• XU QIANGHUI
• SHEN JUN
• TIAN RAN
• WEI MINGSHAN

Assignees

• 北京理工大学

Dates

Publication Date

20260505

Application Date

20230215

Claims (8)

1. 1. An energy storage system based on a thermochemical energy storage and brayton cycle, comprising: The storage device comprises a normal-temperature water storage tank, a calcium hydroxide storage tank and a calcium oxide storage tank, wherein an inlet of the normal-temperature water storage tank is communicated with a water outlet of a first heat exchange network; The energy storage device comprises a calcium hydroxide calcination reactor, a first heat exchange network, a first heat regenerator, a first compressor, a first turbine, a first motor and a first generator, wherein a calcium hydroxide inlet of the calcium hydroxide calcination reactor is communicated with a calcium hydroxide outlet of the first heat exchange network, a calcium oxide outlet of the calcium hydroxide calcination reactor is communicated with a calcium oxide inlet of the first heat exchange network, a water vapor outlet of the calcium hydroxide calcination reactor is communicated with a water vapor inlet of the first heat exchange network, a water outlet of the first heat exchange network, the calcium hydroxide inlet and the calcium oxide outlet are all communicated with the storage device, a first inlet of the first heat regenerator is communicated with a carbon dioxide outlet of the calcium hydroxide calcination reactor, the first compressor is connected in series between a first outlet of the first heat regenerator and the carbon dioxide inlet of the calcium hydroxide calcination reactor, the first turbine is connected in series between a second outlet of the first heat regenerator and the second inlet of the first heat regenerator, a rotating shaft of the first motor is connected with the first compressor, and the rotating shaft of the first turbine is connected with the rotating shaft of the first generator; The energy release device comprises a water preheating heat exchanger, a water vapor generator, a second heat exchanger network, a calcium oxide hydration reaction fluidized bed, a second heat regenerator, a second compressor, a second turbine, a second motor and a second generator, wherein a first inlet of the water preheating heat exchanger is communicated with an outlet of a normal-temperature water storage tank, a first outlet of the water preheating heat exchanger is communicated with an inlet of the water vapor generator, a water vapor outlet of the water vapor generator and a water vapor outlet of the calcium oxide hydration reaction fluidized bed are communicated with a water vapor inlet of the second heat exchanger network, a calcium hydroxide outlet of the second heat exchanger network is communicated with a calcium hydroxide inlet of the calcium hydroxide storage tank, a calcium oxide inlet of the second heat exchanger network is communicated with a calcium oxide outlet of the calcium oxide storage tank, a carbon dioxide inlet of the second heat exchanger network is communicated with a first outlet of the second heat exchanger, a carbon dioxide outlet of the second heat exchanger is communicated with a first inlet of the second heat exchanger network, a water vapor outlet of the second heat exchanger and a water vapor outlet of the second heat exchanger are connected in series with a calcium oxide inlet of the second heat exchanger, a calcium oxide inlet of the second heat exchanger is communicated with a calcium hydroxide inlet of the second heat exchanger is connected with a heat exchanger in series, the rotating shaft of the second generator is connected with the second turbine.
2. 2. The thermochemical energy storage and brayton cycle based energy storage system of claim 1, wherein the energy storage device further comprises: The first cyclone separator is connected in series between the water vapor outlet of the calcium hydroxide calcination reactor and the water vapor inlet of the first heat exchange network.
3. 3. The thermochemical energy storage and brayton cycle based energy storage system of claim 1, wherein the energy storage device further comprises: The first inlet of the industrial waste heat exchanger is communicated with the outlet of the first turbine, and the first outlet of the industrial waste heat exchanger is communicated with the second inlet of the first heat regenerator; and the outlet of the industrial waste heat supply unit is communicated with the second inlet of the industrial waste heat exchanger, and the inlet of the industrial waste heat supply unit is communicated with the second outlet of the industrial waste heat exchanger.
4. 4. The thermochemical energy storage and brayton cycle based energy storage system of claim 1, wherein the energy-releasing apparatus further comprises: the first inlet of the heat supply heat exchanger is communicated with the second outlet of the second heat regenerator, the first outlet of the heat supply heat exchanger is communicated with the second inlet of the water preheating heat exchanger, the second inlet of the heat supply heat exchanger is communicated with the outlet of the end user through a first pipeline, and the second outlet of the heat supply heat exchanger is communicated with the inlet of the end user through a second pipeline; The absorption heat pump comprises an absorption heat pump, a first interface of the absorption heat pump is communicated with a first pipeline through a first valve, a second interface of the absorption heat pump is communicated with the first pipeline through a second valve, a third interface of the absorption heat pump is communicated with a second pipeline through a third valve, and a fourth interface of the absorption heat pump is communicated with the second pipeline through a fourth valve.
5. 5. The thermochemical energy storage and brayton cycle based energy storage system of claim 1, wherein the energy-releasing apparatus further comprises: the water vapor inlet of the second cyclone separator is communicated with the water vapor outlet of the calcium oxide hydration reaction fluidized bed, and the water vapor outlet of the second cyclone separator and the water vapor outlet of the water vapor generator are both communicated with the water vapor inlet of the second heat exchanger network.
6. 6. The thermochemical energy storage and brayton cycle based energy storage system of claim 5, wherein the energy-releasing apparatus further comprises: the steam inlet of the steam mixer is respectively communicated with the steam outlet of the second cyclone separator and the steam outlet of the steam generator, and the steam outlet of the steam mixer is communicated with the steam inlet of the second heat exchanger network.
7. 7. A method of operating a thermochemical energy storage and brayton cycle based energy storage system, wherein the method of operation is based on the thermochemical energy storage and brayton cycle based energy storage system of any of claims 1-6, the method of operation comprising: the method comprises the steps that excess electric power of a power grid is utilized to drive a first motor to rotate, and the first motor drives a first compressor to work so as to compress supercritical carbon dioxide to a high-temperature and high-pressure state; Introducing high-temperature and high-pressure supercritical carbon dioxide into a calcium hydroxide calcination reactor to heat calcium hydroxide, so that the calcium hydroxide is decomposed into calcium oxide solid particles and water vapor; And preheating the calcium hydroxide before entering the calcium hydroxide calcination reactor by utilizing the waste heat carried by the calcium oxide solid particles and the water vapor through a first heat exchange network.
8. 8. The method of operating a thermochemical energy storage and brayton cycle based energy storage system of claim 7, further comprising: calcium oxide solid particles and water vapor are input into a calcium oxide hydration reaction fluidized bed for reaction to generate calcium hydroxide; Inputting the normal-temperature supercritical carbon dioxide into a second compressor to raise the temperature and the pressure; The carbon dioxide subjected to temperature rise and pressure rise by the second compressor is sequentially input into a second heat regenerator and a second heat exchanger network to obtain high-temperature high-pressure supercritical carbon dioxide; Inputting high-temperature and high-pressure supercritical carbon dioxide into a second turbine, so that the second turbine runs and drives a second generator to generate electricity; And inputting the medium-temperature supercritical carbon dioxide into a heat supply heat exchanger, and heating or refrigerating the terminal user by utilizing the reaction waste heat.

Description

Energy storage system based on thermochemical energy storage and Brayton cycle and operation method Technical Field The invention relates to the technical field of energy storage, in particular to an energy storage system based on thermochemical energy storage and Brayton cycle and an operation method. Background The Carnot battery, also called heat pump electricity storage technology, is an energy storage technology capable of storing the electric quantity of the GWh. Compared with the traditional technologies of compressed air energy storage, pumped storage and the like, the Carnot battery has the advantages of being independent of fossil fuel, free of regional condition constraint, capable of providing cold, heat and electricity comprehensive energy service and the like. In general, a carnot battery converts electric energy into heat energy by using a heat pump cycle such as a brayton heat pump or a vapor compression heat pump in an energy storage stage, and stores the heat energy in a heat reservoir and a cold reservoir, and converts the stored heat energy or cold energy into electric energy by using a power cycle such as a brayton heat engine or a rankine cycle in an energy release stage. However, existing carnot cells are mostly energy storage based on sensible or latent heat materials, with low energy density and severe dissipation of long-period stored heat. Thermochemical energy storage is the storage and release of heat by thermal effects of reversible chemical reactions. Compared with the energy storage mode of sensible heat and latent heat, the energy storage device has the advantages of high energy density, suitability for long-time storage and the like, for example, the energy storage density of calcium oxide and calcium hydroxide working substance pairs is 500-600 kWh/ton, which is about 3 times of that of molten salt, 10 times of that of hot water, and no heat insulation measures are needed in the storage process. However, the existing thermochemical energy storage technology has low heat and mass transfer efficiency and poor maintainability, and limits the long-term stable and efficient operation capability. Disclosure of Invention The invention provides an energy storage system based on thermochemical energy storage and Brayton cycle, which effectively realizes conversion, transmission and storage of electric energy, heat energy and chemical energy, has high energy conversion efficiency in the energy conversion and transmission process, can provide comprehensive energy service for cooling, heating and power for end users, and improves the safety and flexibility of a novel electric power system taking renewable energy as a main body. The invention also provides an operation method of the energy storage system based on thermochemical energy storage and Brayton cycle. An embodiment according to a first aspect of the present invention provides an energy storage system based on thermochemical energy storage and brayton cycle, comprising: A storage device; the energy storage device comprises a calcium hydroxide calcination reactor, a first heat exchange network, a first heat regenerator, a first compressor, a first turbine, a first motor and a first generator, wherein a calcium hydroxide inlet of the calcium hydroxide calcination reactor is communicated with a calcium hydroxide outlet of the first heat exchange network, a calcium oxide outlet of the calcium hydroxide calcination reactor is communicated with a calcium oxide inlet of the first heat exchange network, a water vapor outlet of the calcium hydroxide calcination reactor is communicated with a water vapor inlet of the first heat exchange network, a water outlet of the first heat exchange network, the calcium hydroxide inlet and the calcium oxide outlet are all communicated with the storage device, a first inlet of the first heat regenerator is communicated with a carbon dioxide outlet of the calcium hydroxide calcination reactor, the first compressor is connected in series between a first outlet of the first heat regenerator and the carbon dioxide inlet of the calcium hydroxide calcination reactor, the first turbine is connected in series between a second outlet of the first heat regenerator and the second inlet of the first heat regenerator, a rotating shaft of the first motor is connected with the first compressor, and the first generator is connected with the rotating shaft of the first turbine. According to the invention there is provided an energy storage system based on thermochemical energy storage and brayton cycle, the energy storage device further comprising: The first cyclone separator is connected in series between the water vapor outlet of the calcium hydroxide calcination reactor and the water vapor inlet of the first heat exchange network. According to the invention there is provided an energy storage system based on thermochemical energy storage and brayton cycle, the energy storage device further comprising: The first in