Thermal chemical heat storage water vapor circulation storage system and operation method thereof

Abstract

The embodiment of the invention provides a thermochemical heat storage steam circulating storage system and an operation method thereof. The system comprises a steam cooler, a steam heat accumulator, a reaction tank, a steam compressor and a water storage tank. The steam cooler is located in saturated water in the steam heat accumulator, an inlet and an outlet of the steam cooler are connected with a steam exhaust port of the reaction tank and an inlet of the steam compressor respectively, an outlet of the steam compressor is connected with a first inlet of the steam heat accumulator, and an outlet of the water storage tank is connected with a second inlet of the steam heat accumulator; and the outlet of the steam heat accumulator is connected with the steam absorption port of the reaction tank. According to the thermochemical heat storage water vapor circulation storage system, the vapor compressor is adopted for pressurization, the vapor heat accumulator is used for storing water vapor and most of heat of the water vapor, the water vapor needed by a thermal reaction system is cyclically stored and utilized, the system structure is simple, and the efficiency and the heat storage density of the system are greatly improved.

Description

Technical Field

[0001] The embodiments of the present disclosure belong to the technical field of water vapor storage, and specifically relate to a thermochemical water vapor storage system and an operation method thereof. Background Art

[0002] Ca(OH) 2 / CaO thermochemical heat storage system is currently the most promising thermochemical energy storage system for scientific research transformation and commercial application. Similar reaction systems of solid reaction materials and water vapor also have good application prospects. However, as a reactant in the reaction system, the heat carried by water vapor itself is an important part of the reaction system's heat storage and release, accounting for a high proportion. However, since water vapor is difficult to store, many reaction system designs discharge water vapor during the heat storage process and add water vapor from other sources during the hydration reaction in the heat release process. As a result, the reaction system is inefficient, the energy storage density is greatly reduced, and a matching water vapor source is required. Summary of the invention

[0003] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a thermochemical hot water vapor cycle storage system and an operation method thereof.

[0004] In one aspect, an embodiment of the present disclosure provides a thermochemical hot water vapor cycle storage system, the system comprising a steam cooler, a steam accumulator, a reaction tank, a steam compressor, and a water storage tank;

[0005] The steam cooler is located in the saturated water in the steam accumulator, the inlet of the steam cooler is connected to the steam outlet of the reaction tank, the outlet of the steam cooler is connected to the inlet of the steam compressor, the outlet of the steam compressor is connected to the first inlet of the steam accumulator, and the outlet of the water storage tank is connected to the second inlet of the steam accumulator;

[0006] The outlet of the steam accumulator is connected to the steam absorption port of the reaction tank; wherein a medium-temperature steam valve is arranged between the outlet of the steam accumulator and the steam absorption port of the reaction tank, a high-temperature steam valve is arranged between the steam discharge port of the reaction tank and the inlet of the steam cooler, and a water pump is arranged between the water storage tank outlet and the second inlet of the steam accumulator.

[0007] Optionally, the outlet of the steam accumulator is located at the top thereof, and the first inlet and the second inlet of the steam accumulator are both located at the bottom thereof.

[0008] Optionally, a water supply valve is further provided between the water pump and the steam accumulator.

[0009] Optionally, the system further comprises a bypass pipeline;

[0010] The inlet of the bypass pipeline is connected to the pipeline between the high-temperature steam valve and the inlet of the steam cooler, and the outlet of the bypass pipeline is connected to the inlet of the water tank; the bypass pipeline is serially connected with a bypass valve and a heat-to-work conversion expansion device in sequence from its inlet to its outlet.

[0011] Optionally, the outlet of the bypass pipeline is located at the top of the water storage tank, and the outlet of the water storage tank is located at the bottom thereof.

[0012] Optionally, the heat-to-work conversion expansion device is a steam turbine, and the steam cooler is a tube bundle heat exchanger.

[0013] Optionally, the system further comprises a motor;

[0014] The motor is connected to the heat-to-work conversion expansion device and the steam compressor, respectively, and the heat-to-work conversion expansion device, the motor and the steam compressor are coaxially arranged.

[0015] Optionally, the steam compressor is configured as a centrifugal compressor or a positive displacement compressor.

[0016] On the other hand, an embodiment of the present disclosure provides an operation method of a thermochemical hot water vapor storage cycle storage system, using the system described above, the operation method comprising:

[0017] When the reaction tank is undergoing dehydration reaction, close the medium-temperature steam valve, open the high-temperature steam valve and start the water pump;

[0018] When the reaction tank is undergoing a hydration reaction, the medium-temperature steam valve is opened, the high-temperature steam valve is closed, and the water pump is stopped.

[0019] Optionally, when the system further includes a bypass pipeline, the operating method further includes:

[0020] When the reaction tank is undergoing a dehydration reaction, the medium-temperature steam valve is closed, the high-temperature steam valve and the bypass valve are opened, and the water pump is started;

[0021] When the reaction tank is undergoing a hydration reaction, the medium-temperature steam valve is opened, the high-temperature steam valve and the bypass valve are closed, and the water pump is stopped.

[0022] The thermochemical heat storage water vapor circulation storage system and its operation method of the embodiments of the present disclosure can store the water vapor and most of the heat of the chemical heat storage system through the steam accumulator, realize recycling, and form a complete thermochemical heat storage system with the reaction tank. External heat exchange and steam supply devices are no longer required, and the system is greatly simplified and has a high storage efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a schematic structural diagram of a thermochemical water vapor storage system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solution of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0025] like Figure 1 As shown, a thermochemical hot water vapor cycle storage system 100 includes a steam cooler 110, a steam accumulator 120, a reaction tank 130, a steam compressor 140, and a water storage tank 150. The steam cooler 110 is located in saturated water in the steam accumulator 120, the inlet of the steam cooler 110 is connected to the steam outlet of the reaction tank 130, the outlet of the steam cooler 110 is connected to the inlet of the steam compressor 140, the outlet of the steam compressor 140 is connected to the first inlet of the steam accumulator 120, and the outlet of the water storage tank 150 is connected to the second inlet of the steam accumulator 120.

[0026] The outlet of the steam accumulator 120 is connected to the steam absorption port of the reaction tank 130. A medium-temperature steam valve 200 is provided between the outlet of the steam accumulator 120 and the steam absorption port of the reaction tank 130, a high-temperature steam valve 300 is provided between the steam discharge port of the reaction tank 130 and the inlet of the steam cooler 110, and a water pump 400 is provided between the outlet of the water storage tank 150 and the second inlet of the steam accumulator 120.

[0027] Specifically, Figure 1 As shown, the reaction tank 130 is used as a device for discharging and absorbing water vapor, and the steam has two inlet and outlet pipelines, which are controlled by the medium-temperature steam valve 200 and the high-temperature steam valve 300 respectively. The steam discharge outlet of the reaction tank 130 is connected to the inlet of the steam discharge pipeline, and the high-temperature steam valve 300 is connected in series to the steam discharge pipeline. The outlet of the steam discharge pipeline is connected to the inlet of the steam cooler 110 in the steam accumulator 120. Among them, the steam cooler 110 is located in the saturated water in the steam accumulator 120, that is, the steam cooler 110 is immersed below the saturated water level of the steam accumulator 120. The outlet of the steam cooler 110 is connected to the inlet of the steam compressor 140, and the outlet of the steam compressor 140 is connected to the first inlet of the steam accumulator 120. The first inlet is connected to the steam-water space of the steam accumulator 120. The outlet of the water storage tank 150 is connected to the second inlet of the steam accumulator 120. The second inlet is also connected to the steam-water space of the steam accumulator 120.

[0028] When the reaction tank 130 is undergoing a dehydration reaction, the medium-temperature steam valve 200 is closed, the high-temperature steam valve 300 is opened, and the water pump 400 is started. The high-temperature steam generated in the reaction enters the steam cooler 110 through the regulation of the high-temperature steam valve 300, and exchanges heat with the saturated water in the steam accumulator 120, cooling to a temperature slightly higher than its saturation temperature, and then enters the steam compressor 140, and after being pressurized, enters the steam-water space of the steam accumulator 120. At the same time, the water in the water storage tank 150 is pressurized by the water pump 400 and pumped into the steam-water space of the steam accumulator 120, so that the temperature, pressure and water level in the steam accumulator 120 continue to rise until the dehydration reaction is completed.

[0029] When the reaction tank 130 is undergoing a hydration reaction, the medium-temperature steam valve 200 is opened, the high-temperature steam valve 300 is closed, and the water pump 400 is stopped. The water vapor in the steam accumulator 120 enters the reaction tank 130, and the pressure is regulated by the medium-temperature steam valve 200. As the water vapor is discharged, the pressure in the steam accumulator 120 is continuously reduced, and the high-pressure saturated water is continuously flashed into water vapor. During the entire steam supply process, the temperature, pressure, and water level of the steam accumulator 120 are continuously reduced until the hydration reaction is completed.

[0030] The thermochemical heat storage water vapor circulation storage system of the embodiment of the present disclosure can convert the high-temperature water vapor generated by the endothermic decomposition of the reaction system into saturated water at a higher pressure and store it, supplying the saturated steam required for the heat release and hydration process of the reaction system. In other words, the water vapor and most of the heat of the chemical heat storage system can be stored through the steam accumulator for recycling, forming a complete thermochemical heat storage system with the reaction tank, no longer requiring external heat exchange and steam supply devices, and the system can be greatly simplified and has a high storage efficiency.

[0031] Furthermore, if Figure 1 As shown, the system 100 further includes a bypass pipeline 160. The inlet of the bypass pipeline 160 is connected to the pipeline between the high-temperature steam valve 300 and the inlet of the steam cooler 110, and the outlet of the bypass pipeline 160 is connected to the inlet of the water storage tank 150. The bypass pipeline 160 is serially connected with a bypass valve 170 and a heat-work conversion expansion device 180 in sequence from its inlet to its outlet.

[0032] Specifically, Figure 1 As shown, the steam discharge pipeline is also connected to a bypass pipeline 160, and the inlet of the bypass pipeline 160 is located between the high-temperature steam valve 300 and the inlet of the steam cooler 110. The bypass pipeline 160 is connected in series with a bypass valve 170 and a heat-work conversion expansion device 180, and the outlet of the bypass pipeline 160 is connected to the inlet of the water storage tank 150.

[0033] It is not difficult to understand that when the reaction tank 130 performs a dehydration reaction, the medium-temperature steam valve 200 is closed, the high-temperature steam valve 300 is opened, the bypass valve 170 is also opened, and the water pump 400 is started. The high-temperature water vapor generated in the reaction is regulated by the high-temperature steam valve 300 and is divided into two paths. The main path enters the steam cooler 110 and exchanges heat with the saturated water in the steam accumulator 120, cooling to a temperature slightly higher than its saturation temperature, and then enters the steam compressor 140, and enters the steam-water space of the steam accumulator 120 after being pressurized. In addition, there is another bypass pipeline 160 after the high-temperature steam valve 300 to transport steam, and the steam enters the heat-work conversion expansion device 180 through the bypass valve 170, and is discharged into the water storage tank 150 after expansion and work. The flow of the two steam paths is regulated by the bypass valve 170. At the same time, the water in the water storage tank 150 is pressurized by the water pump 400 and pumped into the steam-water space of the steam accumulator 120, so that the temperature, pressure and water level in the steam accumulator 120 continue to rise until the dehydration reaction is completed.

[0034] When the reaction tank 130 is undergoing hydration reaction, the medium temperature steam valve 200 is opened, the bypass valve 170 is closed, the high temperature steam valve 300 is closed, and the water pump 400 is stopped. The water vapor in the steam accumulator 120 enters the reaction tank 130, and the pressure is adjusted by the medium temperature steam valve 200. As the water vapor is discharged, the pressure in the steam accumulator 120 is continuously reduced, and the high pressure saturated water is continuously flashed into water vapor. During the entire steam supply process, the temperature, pressure, and water level of the steam accumulator 120 are continuously reduced until the hydration reaction is completed.

[0035] The system further includes a motor 190. The motor 190 is connected to the heat-to-work conversion expansion device 180 and the steam compressor 140, respectively, and the heat-to-work conversion expansion device 180, the motor 190 and the steam compressor 140 are coaxially arranged. The steam compressor 140, the motor 190 and the heat-to-work conversion expansion device 180 are coaxially arranged, so that the energy of the bypass steam can be fully recovered.

[0036] For similar Ca(OH) 2 / CaO+H 2 O and other steam-solid reversible reaction systems, the embodiments of the present disclosure can heat exchange and cool most of the high-temperature water vapor discharged from the reaction system, and then pressurize and inject it into the steam accumulator. At the same time, another part of the high-temperature water vapor is used to expand and do work, providing part of the power for the steam compressor, and fully utilizing and storing the thermal energy of the water vapor. The total mass of water vapor and more than 80% of the heat required by the reaction system can be stored and recycled, so that the chemical heat storage system has extremely high energy storage efficiency and heat storage density.

[0037] As a specific example, Figure 1As shown, the reaction tank 130 is a container and reactor for chemical heat storage solid medium, and the reaction water vapor pressure is generally 0.1MPa to 1MPa. For example, if the reaction temperature is required to be around 500°C, the pressure of the container is about 0.5MPa. The reaction tank 130 is filled with reaction materials, such as Ca(OH) 2 and CaO powder (granules or other forms) and water vapor, the reaction equation is Ca(OH) 2 <——>CaO+H 2 O.

[0038] During the heat storage process of the chemical heat storage system, the reaction process generates high-temperature water vapor, and most of the water vapor is discharged from the reaction tank through pipes and high-temperature steam valves to maintain the stability of the pressure in the reaction tank. The discharged high-temperature water vapor is cooled to a temperature slightly higher than its saturation temperature by the steam cooler, and then pressurized by the steam compressor before entering the steam accumulator. At the same time, the water pump pumps normal temperature water into the steam accumulator, and the water level, pressure and temperature of the steam accumulator gradually rise to complete the storage of water vapor and its heat. A small part of the high-temperature water vapor enters the heat-to-work conversion expansion device through the bypass valve to expand and do work, providing part of the power for the steam compressor, and then is discharged into the water storage tank for condensation.

[0039] During the heat release process of the chemical heat storage system, water vapor needs to be added to the reaction. The saturated water stored in the steam accumulator flashes and is supplied to the reaction tank through the medium-temperature steam valve, and the pressure of the reaction tank is kept stable. Since the pressure of the steam accumulator is higher than that of the reaction tank, the steam accumulator can continuously provide all the steam required for the reaction.

[0040] The thermochemical heat storage water vapor circulation storage system of the embodiment of the present disclosure stores the water vapor and most of the heat of the chemical heat storage system through a steam accumulator for recycling, and forms a complete thermochemical heat storage system with the reaction tank. External heat exchange and steam supply devices are no longer required, and the system is greatly simplified and has a high storage efficiency.

[0041] For example, Figure 1 As shown, a water supply valve 500 is further provided between the water pump 400 and the steam accumulator 120. The water in the water storage tank 150 can also be supplied to or stopped from the steam accumulator 120 by controlling the opening or closing of the water supply valve 500.

[0042] For example, Figure 1As shown, the outlet of the steam accumulator 120 is located at the top thereof, and the first inlet and the second inlet of the steam accumulator 120 are both located at the bottom thereof. Such a configuration facilitates the direct delivery of the steam in the steam accumulator 120 to the reaction tank 130. It is also convenient to receive the pressurized steam from the steam compressor 140 and the normal temperature water from the water storage tank 150, which are directly mixed in the steam accumulator 120 so that the temperature, pressure and water level in the steam accumulator 120 continue to rise. The system is simple as a whole and the working process is clear and concise.

[0043] For example, Figure 1 As shown, the outlet of the bypass pipe 160 is located at the top of the water storage tank 150, and the outlet of the water storage tank 150 is located at the bottom thereof. Such a configuration facilitates the water storage tank to directly condense the exhaust steam from the heat-work conversion expansion device 180 into water, and to fully discharge the condensed water to the steam accumulator 120, thereby avoiding wasting the condensed water.

[0044] For example, Figure 1 As shown, the heat-to-work conversion expansion device 180 is a steam turbine, and the steam cooler 110 is a tube bundle heat exchanger. The function of the steam turbine is to expand a portion of the energy of the high-temperature steam to do work and recover the energy of this portion of the steam. The tube bundle of the tube bundle heat exchanger is steam inside, and the inside and outside are isolated. Its function is to use the saturated water in the steam accumulator 120 to cool the high-temperature steam to a temperature slightly higher than its saturation temperature without condensation.

[0045] For example, Figure 1 As shown, the steam compressor 140 is configured as a centrifugal compressor or a positive displacement compressor. It can pressurize the cooled steam and press it into the steam accumulator 120. The power of the steam compressor 140 is provided by the motor 190 and the steam turbine, preferably in a coaxial arrangement.

[0046] For example, Figure 1 As shown, the water storage tank 150 is a container for water at normal temperature and pressure, which is used to collect steam from the steam turbine and provide sufficient water for the steam accumulator 120 through the water pump 400.

[0047] On the other hand, an embodiment of the present disclosure provides an operation method of a thermochemical hot water vapor circulation storage system, which adopts the system described above. The specific structure of the system can refer to the relevant records in the above text, and will not be described in detail here. The operation method includes: when the reaction tank performs a dehydration reaction, closing the medium-temperature steam valve, opening the high-temperature steam valve and starting the water pump. When the reaction tank performs a hydration reaction, opening the medium-temperature steam valve, closing the high-temperature steam valve and stopping the water pump.

[0048] Furthermore, when the system further includes a bypass pipeline, the operation method further includes: when the reaction tank performs a dehydration reaction, closing the medium-temperature steam valve, opening the high-temperature steam valve and the bypass valve, and starting the water pump. When the reaction tank performs a hydration reaction, opening the medium-temperature steam valve, closing the high-temperature steam valve and the bypass valve, and stopping the water pump.

[0049] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the embodiments of the present disclosure, but the embodiments of the present disclosure are not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the embodiments of the present disclosure, and these modifications and improvements are also considered to be within the protection scope of the embodiments of the present disclosure.

Claims

1. A thermochemical hot water vapor circulation storage system, characterized in that: The system includes a steam cooler, a steam accumulator, a reaction tank, a steam compressor and a water storage tank; The steam cooler is located in the saturated water in the steam accumulator, the inlet of the steam cooler is connected to the steam outlet of the reaction tank, the outlet of the steam cooler is connected to the inlet of the steam compressor, the outlet of the steam compressor is connected to the first inlet of the steam accumulator, and the outlet of the water storage tank is connected to the second inlet of the steam accumulator; The outlet of the steam accumulator is connected to the steam absorption port of the reaction tank; wherein a medium-temperature steam valve is arranged between the outlet of the steam accumulator and the steam absorption port of the reaction tank, a high-temperature steam valve is arranged between the steam discharge port of the reaction tank and the inlet of the steam cooler, and a water pump is arranged between the water storage tank outlet and the second inlet of the steam accumulator.

2. The thermochemical hot water vapor cycle storage system according to claim 1, characterized in that: The outlet of the steam accumulator is located at the top thereof, and the first inlet and the second inlet of the steam accumulator are both located at the bottom thereof.

3. The thermochemical hot water vapor cycle storage system according to claim 1, characterized in that: A water supply valve is also provided between the water pump and the steam accumulator.

4. The thermochemical hot water vapor cycle storage system according to any one of claims 1 to 3, characterized in that: The system also includes a bypass line; The inlet of the bypass pipeline is connected to the pipeline between the high-temperature steam valve and the inlet of the steam cooler, and the outlet of the bypass pipeline is connected to the inlet of the water tank; the bypass pipeline is serially connected with a bypass valve and a heat-to-work conversion expansion device in sequence from its inlet to its outlet.

5. The thermochemical hot water vapor cycle storage system according to claim 4, characterized in that: The outlet of the bypass pipeline is located at the top of the water storage tank, and the outlet of the water storage tank is located at the bottom thereof.

6. The thermochemical hot water vapor cycle storage system according to claim 4, characterized in that: The heat-to-work conversion expansion device is a steam turbine, and the steam cooler is a tube bundle heat exchanger.

7. The thermochemical hot water vapor cycle storage system according to claim 4, characterized in that: The system also includes a motor; The motor is connected to the heat-to-work conversion expansion device and the steam compressor, respectively, and the heat-to-work conversion expansion device, the motor and the steam compressor are coaxially arranged.

8. The thermochemical hot water vapor cycle storage system according to any one of claims 1 to 3, characterized in that: The steam compressor is configured as a centrifugal compressor or a positive displacement compressor.

9. A method for operating a thermochemical hot water vapor cycle storage system, characterized in that: Using the system according to any one of claims 1 to 8, the operating method comprises: When the reaction tank is undergoing dehydration reaction, close the medium-temperature steam valve, open the high-temperature steam valve and start the water pump; When the reaction tank is undergoing a hydration reaction, the medium-temperature steam valve is opened, the high-temperature steam valve is closed, and the water pump is stopped.

10. The operating method according to claim 9, characterized in that: When the system further includes a bypass pipeline, the operating method further includes: When the reaction tank is undergoing a dehydration reaction, the medium-temperature steam valve is closed, the high-temperature steam valve and the bypass valve are opened, and the water pump is started; When the reaction tank is undergoing a hydration reaction, the medium-temperature steam valve is opened, the high-temperature steam valve and the bypass valve are closed, and the water pump is stopped.

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