Pressure-holding Heat Storage Component with Water as Heat Transfer Medium, Its Control Method and Water Heat Storage and Release Component

Abstract

An embodiment of the present invention discloses a pressure-maintaining heat storage component using water as a heat exchange medium, its control method, and a water heat storage and release component. The pressure-maintaining heat storage component includes: a steam heating component, including a steam generation part for evaporating feed water to generate water vapor; a heat storage unit for storing high-temperature water and water vapor; a heat release and pressure-maintaining flow path, with an input end connected to the steam generation part and an output end connected to the heat storage unit; in the heat release stage, the water vapor output by the steam generation part can be input into the heat storage unit through the heat release and pressure-maintaining flow path, and the heat storage unit outputs high-temperature water. The volume of the water vapor input into the heat storage unit is equal to or greater than the volume of the high-temperature water output from the heat storage unit to keep the pressure of the heat storage unit stable within a preset pressure range during the heat release stage. The embodiment of the present invention can ensure the pressure stability of the heat storage unit during the heat release process, and has the characteristics of high heat storage efficiency, safety and stability, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage, and particularly to a pressure-maintaining heat storage component with water as a heat exchange medium, its control method, and a water heat storage and release component. Background Art

[0002] The gas-liquid two-phase carbon dioxide energy storage system mainly uses carbon dioxide as a circulating working medium. The specific structure of the carbon dioxide energy storage system can be understood by referring to the carbon dioxide energy storage devices / systems disclosed in Chinese Patent Publication Nos. CN112985143B, CN112985144B, CN112985145B, and CN114109549B. During the energy storage stage, the carbon dioxide working medium is heated and pressurized by a compressor. After the compressed high-temperature and high-pressure carbon dioxide is exchanged heat with the heat storage medium, the liquid carbon dioxide and the high-temperature heat storage medium are stored. During the energy release stage, the liquid carbon dioxide is heated by the high-temperature heat storage medium into a high-temperature and high-pressure gaseous working medium, which then drives a turbine to do work and generate electricity, completing the conversion of pressure energy and heat energy.

[0003] Common heat storage media include molten salt, heat transfer oil, and water, which are used to achieve the heat energy conversion of carbon dioxide during the energy storage and release stages. During use, molten salt is affected by the intermittent operation of the energy storage system, resulting in molten salt solidification, pipeline blockage, and production accidents. As a bulk product, heat transfer oil is significantly affected by international crude oil prices and varies significantly with the capacity and duration of the energy storage system. In particular, it accounts for a significant proportion in the investment cost of a long-duration energy storage system. At the same time, heat transfer oil is a flammable liquid, and once it leaks and comes into contact with air, it is prone to catching fire, posing a huge safety hazard during use. Replacing molten salt and heat transfer oil with high-pressure water can solve many problems during use, but conventional containers for storing high-pressure water use compressed air and nitrogen for pressure maintenance, resulting in a large waste of high-pressure air and nitrogen during use, which is extremely uneconomical. Summary of the Invention

[0004] Therefore, to solve the problem of waste in the pressure maintenance of high-pressure water during the heat storage process in the heat storage unit in the prior art, the embodiments of the present invention provide a pressure-maintaining heat storage component with water as a heat exchange medium, its control method, and a water heat storage and release component, which can ensure the pressure stability of high-pressure water in the heat storage unit during the heat release process, and have the characteristics of high heat storage efficiency, safety, and stability.

[0005] An embodiment of the present invention provides a pressure-maintaining heat storage component with water as the heat exchange medium, including: a steam heating component, the steam heating component includes a steam generation part, and the steam generation part is used to evaporate feed water to generate water vapor; a heat storage unit for storing high-temperature water and water vapor; a heat release and pressure-maintaining flow path, the input end of the heat release and pressure-maintaining flow path is connected to the steam generation part, and the output end of the heat release and pressure-maintaining flow path is connected to the heat storage unit; in the heat release stage, the water vapor output by the steam generation part can be input into the heat storage unit through the heat release and pressure-maintaining flow path, and the heat storage unit outputs the high-temperature water, and the volume of the water vapor input into the heat storage unit is equal to or greater than the volume of the high-temperature water output from the heat storage unit, so as to keep the pressure of the heat storage unit stable within a preset pressure range in the heat release stage.

[0006] In one embodiment, the steam generation part includes a steam generator and a steam distributor, the steam generator is used to generate water vapor; the steam distributor is used to distribute the water vapor generated by the steam generator and then output it to the heat storage unit; the input end of the heat release and pressure-maintaining flow path is connected to the steam distributor.

[0007] In one embodiment, a steam pressure reducing device is arranged on the heat release and pressure-maintaining flow path, and the steam pressure reducing device is used to reduce the pressure of the water vapor input from the steam heating component to the preset pressure range and then output it to the heat storage unit.

[0008] In one embodiment, the pressure-maintaining heat storage component with water as the heat exchange medium further includes a heat storage and pressure-maintaining flow path, the input end of the heat storage and pressure-maintaining flow path is connected to the heat storage unit, and the output end of the heat storage and pressure-maintaining flow path is connected to the steam generation part; in the heat storage stage, the heat storage unit inputs the high-temperature water, and the water vapor stored in the heat storage unit can be discharged to the steam generation part through the heat storage and pressure-maintaining flow path, and the volume of the high-temperature water input into the heat storage unit is equal to or greater than the volume of the water vapor discharged from the heat storage unit, so as to keep the pressure of the heat storage unit stable within the preset pressure range in the heat storage stage.

[0009] In one embodiment, a check valve is arranged on the heat storage and pressure-maintaining flow path, and the inlet end of the check valve is connected to the heat storage unit.

[0010] An embodiment of the present invention provides a water heat storage and release component, including the pressure-maintaining heat storage component with water as the heat exchange medium described in any one of the foregoing.

[0011] In one embodiment, the water storage and heat release assembly further includes an energy release heat exchanger and a return water pipeline; the energy release heat exchanger is configured to exchange heat and cool down the high-temperature water input by the heat storage unit and then output it during the heat release stage; the steam heating assembly further includes a water storage container for storing feed water; the input end of the return water pipeline is connected to the energy release heat exchanger, and the output end of the return water pipeline is connected to the water storage container; the return water pipeline is configured to transport the water cooled down by the energy release heat exchanger to the water storage container.

[0012] In one embodiment, a return water pressure reducing device is provided on the return water pipeline, and the return water pressure reducing device is configured to reduce the pressure of the water cooled down by the energy release heat exchanger and then output it to the water storage container.

[0013] In one embodiment, the water storage and heat release assembly further includes a water supply unit and an energy storage heat exchanger. The water supply unit is connected between the water storage container and the energy storage heat exchanger, and the water supply unit is configured to transport the feed water to the energy storage heat exchanger during the heat storage stage; the energy storage heat exchanger is connected to the heat storage unit, and the energy storage heat exchanger is configured to exchange heat and heat up the input feed water into high-temperature water and then output it to the heat storage unit during the heat storage stage.

[0014] An embodiment of the present invention further provides a control method for a pressure maintaining heat storage assembly with water as a heat exchange medium. Based on the pressure maintaining heat storage assembly described in any one of the foregoing, the control method includes: during the heat release stage, part of the steam generated by the steam generation part is transported to the heat storage unit through the heat release pressure maintaining flow path, and the heat storage unit outputs the high-temperature water. The volume of the steam flowing into the heat storage unit is equal to or greater than the volume of the high-temperature water flowing out of the heat storage unit, so as to keep the pressure in the heat storage unit stable within the preset pressure range during the heat release stage.

[0015] As can be seen from the above, the above embodiments of the present invention can achieve one or more of the following beneficial effects: by providing a heat release pressure maintaining flow path corresponding to the heat storage unit, the heat release pressure maintaining flow path is connected to the steam generation part of the steam heating assembly. During the heat release stage, the high-temperature water in the heat storage unit outputs energy, which will cause the water level in the heat storage unit to drop and the pressure to decrease. Water steam is supplemented into the heat storage unit through the heat release pressure maintaining flow path to balance the water pressure change in the heat storage unit caused by the output of the high-temperature water, prevent problems such as boiling and vaporization of the high-temperature water due to too low pressure in the heat storage unit, and maintain the stable operation of the heat storage unit during the heat release stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following will describe in detail the specific embodiments of the present invention in conjunction with the drawings.

[0017] Figure 1Schematic structural diagram of an embodiment of the pressure-maintaining heat storage component using water as the heat exchange medium provided by the present invention.

[0018] Figure 2 Schematic structural diagram of another embodiment of the pressure-maintaining heat storage component using water as the heat exchange medium provided by the present invention.

[0019] Figure 3 Schematic structural diagram of another embodiment of the pressure-maintaining heat storage component using water as the heat exchange medium provided by the present invention.

[0020] Figure 4 Schematic structural diagram of an embodiment of the water heat storage and release component provided by the present invention.

[0021] Figure 5 Schematic structural diagram of another specific embodiment of the water heat storage and release component provided by the present invention.

[0022] Figure 6 Schematic structural diagram of another specific embodiment of the water heat storage and release component provided by the present invention.

[0023]

Description of the reference numerals

[0024] 10: Steam heating component; 11: Steam generation part; 111: Steam generator; 112: Steam distributor; 12: Water storage container; 13: Water supply pipeline; 14: Booster pump; 22 Energy storage heat exchanger; 23: Heat storage unit; 24: Energy release heat exchanger; 26: Energy release circulation pump; 271: Energy storage isolation valve; 272: Energy release isolation valve; 28: Return water pipeline; 29: Return water pressure reducing device; 32: Heat storage pressure-maintaining flow path; 321: Check valve; 33: Heat release pressure-maintaining flow path; 33: Steam pressure reducing device; 333: Steam regulating valve; 40: Water supply unit; 41: First pipeline; 42: Second pipeline; 43: Feed water pump; 44: Feed water isolation valve; 45: Make-up water regulating valve; Dashed arrow: Schematic of the water vapor flow direction; Solid arrow: Schematic of the water flow direction. Detailed description of the specific embodiments

[0025] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings.

[0026] In order to enable those of ordinary skill in the art to better understand the technical solutions of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] It should be noted that the terms "first", "second", etc. in the description, claims and the above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0028] It should also be noted that the division of multiple embodiments in the present invention is only for the convenience of description and should not constitute a special limitation. The features in various embodiments can be combined and cross-referenced without contradiction.

[0029] As Figure 1 shown, the embodiment of the present invention provides a pressure-maintaining heat storage component with water as the medium (hereinafter simply referred to as the pressure-maintaining heat storage component), which can be applied to phase change energy storage systems such as carbon dioxide energy storage systems or energy storage systems such as compressed air energy storage systems. The pressure-maintaining heat storage component provided in this embodiment includes a steam heating component 10, a heat storage unit 23, and a heat release and pressure-maintaining flow path 33.

[0030] Among them, the steam heating component 10 is used to receive steam and output steam for use by a steam user 15 (see Figure 6 ). The steam heating component 10 includes a steam generation part 11. The steam generation part 11 is used to evaporate the input feed water to generate steam. The steam generated by the steam generation part 11 can be transported to the steam user 15 (see Figure 6 ) for use. The steam heating component 10 can be a steam heating system for civil or industrial use, with water as the heating medium and transported to the user in the form of pressurized steam. In some embodiments, when there is no external steam heating component 10 near the pressure-maintaining heat storage component with water as the medium, the steam heating component 10 can be rebuilt and the steam can be used for plant heating. The feed water of the steam heating component 10 can be the feed water input by an external structure or the feed water stored inside the steam heating component 10.

[0031] The heat storage unit 23 is used to store high-temperature water and steam. The heat storage unit 23 can output the stored high-temperature water during the heat release stage. The input end of the heat release and pressure maintaining flow path 33 is connected to the steam generating part 11, and the output end of the heat release and pressure maintaining flow path 33 is connected to the heat storage unit 23. During the heat release stage, the steam output by the steam heating assembly 10 can flow into the heat storage unit 23 through the heat release and pressure maintaining flow path 33. The heat storage unit 23 outputs the high-temperature water. The volume of the steam input into the heat storage unit 23 is equal to or greater than the volume of the high-temperature water output from the heat storage unit 23 to keep the pressure of the heat storage unit 23 stable within a preset pressure range during the heat release stage. Here, the high temperature of the high-temperature water is a relative relationship, indicating that the water stored in the heat storage unit 23 can be output for cooling to release heat. The water temperature of the high-temperature water stored in the heat storage unit 23 is, for example, 150 - 220 °C.

[0032] During the heat release stage, the high-temperature water in the heat storage unit 23 is output to release heat, resulting in a decrease in the water level and pressure in the heat storage unit 23. Through the setting of the heat release and pressure maintaining flow path 33, steam can be supplemented into the heat storage unit 23 during the heat release stage to balance the water pressure change in the heat storage unit 23 caused by the output of the high-temperature water, prevent problems such as boiling of the high-temperature water due to too low pressure in the heat storage unit 23, maintain the pressure balance of the heat storage unit 23 during the heat release stage, and further ensure the stable operation of the heat release process. And the pressure maintaining heat storage assembly provided in this embodiment is particularly suitable for a carbon dioxide gas-liquid two-phase energy storage system coupled with a thermal power plant. The steam generating part 11 can be a boiler of a thermal power plant, which can realize the rational utilization of resources. Compared with nitrogen or compressed air for pressure maintaining, the economic cost is lower.

[0033] In some embodiments, referring to Figure 2 , the steam generating part 11 includes a steam generator 111 and a steam distributor 112. The steam generator 111 is used to evaporate feed water to generate steam, and the steam distributor 112 is used to distribute the steam generated by the steam generator 111 and then output it to the heat storage unit 23, and can also be used to distribute the steam generated by the steam generator 111 and then output it to the steam user 15. The input end of the heat release and pressure maintaining flow path 33 is specifically connected to the steam distributor 112. The steam generated by the steam generator 111 can be respectively distributed to the steam user and the heat storage unit 23 through the steam distributor 112, so that the steam input into the heat release and pressure maintaining flow path 33 better meets the pressure and flow requirements of the heat storage unit 23.

[0034] In some embodiments, referring to Figure 2, a steam pressure reducing device 331 is provided on the heat release and pressure maintaining flow path 33. The steam pressure reducing device 331 is used to reduce the pressure of the water steam input by the steam heating component 10 to a preset pressure range and then output it to the heat storage unit. The steam pressure reducing device 331 can be, for example, a pressure reducing valve, which can rely on the energy of the water steam itself to automatically keep the outlet pressure stable. By setting the steam pressure reducing device 331, the pressure of the water steam input into the heat storage unit 23 can be ensured to be stable, so as to maintain the pressure stability in the heat storage unit 23.

[0035] In some embodiments, the steam pressure reducing device 331 also has a function of cooling, for example, which can cool the input water steam to a preset temperature and then output it to the heat storage unit 23. The preset temperature is, for example, the same as the temperature of the high-temperature water stored in the heat storage unit 23, so as to avoid pressure fluctuations caused by heat exchange between the high-temperature water stored in the heat storage unit 23 and the input water steam.

[0036] Among them, the steam pressure reducing device 331 can be, for example, a temperature reducing and pressure reducing valve to achieve the effects of reducing the steam temperature and controlling the outlet pressure at the same time.

[0037] Referring to Figure 3 , in some embodiments, the pressure maintaining and heat storage component further includes a heat storage and pressure maintaining flow path 32. The input end of the heat storage and pressure maintaining flow path 32 is connected to the heat storage unit 23, and the output end of the heat storage and pressure maintaining flow path 32 is connected to the steam generating part 11, specifically connected to the steam distributor 112. In the heat storage stage, the heat storage unit 23 inputs high-temperature water. The water steam stored in the heat storage unit 23 can be discharged to the steam generating part 11 through the heat storage and pressure maintaining flow path 32. The volume of the high-temperature water input into the heat storage unit 23 is equal to or greater than the volume of the water steam discharged from the heat storage unit 23, so as to keep the pressure in the heat storage unit 23 stable within a preset pressure range during the heat storage stage.

[0038] During the heat storage stage, as high-temperature water is gradually input into the heat storage unit 23, the water level in the heat storage unit 23 rises and the pressure increases. Therefore, in this embodiment, the steam in the heat storage unit 23 can be discharged through the heat storage pressure maintaining flow path 32 during the heat storage stage, preventing the pressure in the heat storage unit 23 from being too high and exceeding the pressure bearing limit of the equipment, ensuring safe and stable operation. In addition, the output end of the heat storage pressure maintaining flow path 32 is specifically connected to the steam generating part 11, and more specifically, the output end of the heat storage pressure maintaining flow path 32 is connected to the steam distributor 112. Through such a setting, the steam discharged from the heat storage pressure maintaining flow path 32 can be combined with the steam generated by the steam heating assembly 10 and then transported to the steam user 15 for use, realizing the efficient utilization of resources. And during the heat release stage, the steam output by the steam distributor 112 can be input into the heat storage unit 23 through the heat release pressure maintaining flow path 33. During the heat storage stage, the originally stored steam in the heat storage unit 23 is discharged to the steam distributor 112 of the steam heating assembly 10 through the heat storage pressure maintaining flow path 32. In this way, a closed cycle of the pressure maintaining working medium steam between the steam distributor 112 and the heat storage unit 23 can be realized during the heat storage stage and the heat release stage.

[0039] Specifically, referring to Figure 3 , in some embodiments, a check valve 321 is provided on the heat storage pressure maintaining flow path 32, and the inlet end of the check valve 321 is connected to the heat storage unit 23. During the heat storage stage, as the water level in the heat storage unit 23 rises, the check valve 321 gradually opens, so that the steam in the heat storage unit 23 is discharged from the heat storage pressure maintaining flow path 32, and the check valve 321 closes after the pressure in the heat storage unit 23 is stable (reaches the preset pressure range). Through the setting of the check valve 321, the steam can be automatically discharged when the water level in the heat storage unit 23 rises, and the discharge of steam automatically stops after the pressure in the heat storage unit 23 is stable.

[0040] In some embodiments, referring to Figure 3 , a steam discharge port is provided at the top of the heat storage unit 23, and the input end of the heat storage pressure maintaining flow path 32 is specifically connected to the steam discharge port. In this embodiment, the heat storage pressure maintaining flow path 32 is connected to the steam discharge port at the top of the heat storage unit 23, which can ensure that when the water level in the heat storage unit 23 rises or due to other reasons, the pressure in the heat storage unit 23 increases during the heat storage stage, the steam can be smoothly discharged from the heat storage pressure maintaining flow path 32 to ensure the pressure balance in the heat storage unit 23 and ensure safe operation.

[0041] An embodiment of the present invention further provides a water heat storage and release component, which includes the pressure-maintaining heat storage component using water as the heat exchange medium described in any one of the foregoing. It can be applied to phase change energy storage systems such as carbon dioxide energy storage systems or energy storage systems such as compressed air energy storage systems. It has the same effect as the foregoing pressure-maintaining heat storage component, and can supplement water vapor into the heat storage unit through the heat release and pressure-maintaining flow path to balance the water pressure change in the heat storage unit caused by the output of the high-temperature water, prevent problems such as boiling and vaporization of the high-temperature water due to too low pressure in the heat storage unit, and maintain the stable operation of the heat storage unit during the heat release stage to maintain the stable operation of the water heat storage and release component.

[0042] Refer to Figure 4 , in some embodiments, the water heat storage and release component further includes an energy release heat exchanger 24 and a return water pipeline 28. The energy release heat exchanger 24 is used to exchange heat and cool down the high-temperature water input from the heat storage unit 23 and then output it during the heat release stage. The steam heating component 10 further includes a water storage container 12, and the water storage container 12 is used to store feed water.

[0043] The input end of the return water pipeline 28 is connected to the energy release heat exchanger 24, and the output end of the return water pipeline 28 is connected to the water storage container 12. The return water pipeline 28 is used to convey the water cooled by the energy release heat exchanger 24 to the steam heating component 10 (specifically to the water storage container 12) during the heat release stage. So that the cooled water obtained during the heat release stage can return to the steam heating component 10 to be evaporated to generate steam for the steam user 15 (refer to Figure 6 ) for use, achieving the effect of efficiently utilizing resources and energy. And by providing the water to be heated and exchanged to the energy storage heat exchanger 22 through the water storage container 12, the cold storage container can be cancelled. During the heat storage stage, the water output from the water storage container 12 to the energy storage heat exchanger 22 is heated and stored in the heat storage unit 23. The high-temperature water stored in the heat storage unit 23 is output to the energy release heat exchanger 24 during the heat release stage to be cooled and then flows back to the water storage container 12 through the return water pipeline 28. In this way, the water storage container 12 replaces the cold storage container, realizing a closed-loop circulation of the feed water between the water storage container 12 and the heat storage unit 23 during the heat storage stage and the heat release stage.

[0044] Among them, the hot side channel of the energy release heat exchanger 24 is connected to the heat storage unit 23, and the cold side channel of the energy release heat exchanger 24 is connected to, for example, the energy release component of the carbon dioxide energy storage system, so as to release the heat stored in the heat storage unit 23 through the energy release heat exchanger 24 during the energy release process of liquid carbon dioxide expanding into gaseous carbon dioxide in the carbon dioxide energy storage system.

[0045] In some embodiments, a return water pressure reducing device 29 is further provided on the return water pipeline 28. The return water pressure reducing device 29 is used to reduce the pressure of the water cooled by the energy release heat exchanger 24 and then output it to the water storage container 12. The return water pressure reducing device 29 can be set as a pressure reducing valve, which can automatically keep the outlet pressure stable by relying on the energy of the water itself. By setting the return water pressure reducing device 29, it can be ensured that the water input into the water storage container 12 better meets the operating pressure requirements.

[0046] In some embodiments, the steam heating assembly 10 further includes a water supply pipeline 13, which is connected between the water storage container 12 and the steam generation part 11. The water supply pipeline 13 is used to convey the feed water in the water storage container 12 to the steam generation part 11. The water supply pipeline 13 is specifically connected between the water storage container 12 and the steam generator 111, and the steam generator 111 is used to evaporate the feed water provided by the water storage container 12 to generate water vapor.

[0047] In some embodiments, referring to Figure 4 , the steam generation part 11 is used to generate water vapor and output it to the steam user 15. The steam heating assembly 10 further includes a condensate recovery pipeline 16 connected between the steam user 15 and the water storage container 12. The condensate recovery pipeline 16 is used to convey the condensate generated after the water vapor is condensed by the steam user 15 to the water storage container 12. The water vapor generated by the steam generation part 11 is conveyed to the steam user 15 and then the condensate generated after being absorbed and condensed flows back to the water storage container 12, which can realize the water cycle of the steam heating assembly 10 and avoid waste of resources.

[0048] Figure 4 The connection structure of a specific embodiment of the steam heating assembly 10 in the water storage and heat release assembly is shown, where the steam heating assembly 10 specifically includes a water storage container 12, a booster pump 14, a steam generator 111, a steam distributor 112 and a steam user 15 that are connected in a closed loop in sequence. The steam generation part 11 includes the steam generator 111 and the steam distributor 112. The steam generator 111 is used to evaporate the feed water to generate water vapor, and the steam distributor 112 is used to distribute and output the water vapor. The steam distributor 112 distributes the water vapor according to the pressure and flow rate required by different steam users 15. The heating process of the steam heating assembly 10 is that the booster pump 14 conveys the water in the water storage container 12 to the steam generator 111, and the steam generator 111 evaporates the water to generate steam and then the steam is distributed to different steam users 15 by the steam distributor 112. After the steam is absorbed by the steam user 15, the steam condenses into condensate, realizing water resource recovery.

[0049] Referring to Figure 5 and Figure 6, the water storage and heat release component provided by the embodiment of the present invention further includes a water supply unit 40 and a heat storage heat exchanger 22. The water supply unit 40 is connected between the water storage container 12 and the heat storage heat exchanger 22, and the water supply unit 40 is used to convey the feed water in the water storage container 12 to the heat storage heat exchanger 22 during the heat storage stage. The heat storage heat exchanger 22 is connected to the heat storage unit 23, and the heat storage heat exchanger 22 is used to heat and raise the temperature of the input feed water to high-temperature water and then output it to the heat storage unit 23 during the heat storage stage. Among them, the cold-side channel of the heat storage heat exchanger 22 is connected to the heat storage unit 21, and the hot-side channel of the heat storage heat exchanger 22 is connected to the energy storage component of the carbon dioxide energy storage system, for example, so as to store part of the heat in the high-temperature water through the heat storage heat exchanger 22 during the energy storage process of compressing gaseous carbon dioxide into liquid carbon dioxide in the carbon dioxide energy storage system.

[0050] In some embodiments, the steam heating component 10 further includes a booster pump 14. For example, the booster pump is arranged on the water supply pipeline 13. The inlet end of the booster pump 14 is connected to the water storage container 12, and the outlet end of the booster pump 14 is connected to the steam generation part 11. Refer to Figure 5 , in some embodiments, the water supply unit 40 includes a first pipeline 41. The first pipeline 41 is connected between the outlet end of the booster pump 14 and the heat storage heat exchanger 22, and the first pipeline 41 is used to convey the feed water boosted by the booster pump 14 to the heat storage heat exchanger 22. For example, a feed water isolation valve 44 is arranged on the first pipeline 41. The feed water isolation valve 44 remains closed during the non-heat storage stage. During the heat storage stage, if the booster pump 14 operates, the feed water isolation valve 44 is opened, so that a part of the water discharged from the booster pump 14 is provided to the steam generator 111 to generate steam, and the other part is conveyed to the heat storage heat exchanger 22 for heat exchange and temperature rise. That is, the booster pump 14 can be reused as the boosting device of the water supply unit 40, which can jointly provide a preset pressure for the feed water conveyed to the steam generation part 11 and the heat storage heat exchanger 22, realizing the sharing of equipment and reducing the equipment cost.

[0051] In some embodiments, refer to Figure 6 , the water supply unit 40 includes a second pipeline 42 connected between the water storage container 12 and the heat storage heat exchanger 22. A feed water pump 43 is arranged on the second pipeline 42. The inlet end of the feed water pump 43 is connected to the water storage container 12, and the outlet end of the feed water pump 43 is connected to the heat storage heat exchanger 22. The feed water pump 43 is used to boost the feed water output from the water storage container 12 and then convey it to the heat storage heat exchanger 22. By setting the second pipeline 42 and the feed water pump 43, it can be designed according to the pressure required during the heat storage stage, so that the water pressure output to the heat storage heat exchanger 22 meets the operation requirements.

[0052] In some embodiments, the water supply unit 40 may separately provide the second pipeline 42 and the water supply pump 43. During the heat storage stage, the water is conveyed to the energy storage heat exchanger 22 through the second pipeline 42 under the pressure provided by the water supply pump 43. Alternatively, the first pipeline 41, the second pipeline 42, and the water supply pump 43 may be provided simultaneously. During the heat storage stage, if the booster pump 14 is operating normally, a part of the water discharged from the booster pump 14 is supplied to the steam generator 111 to generate steam, and the other part is conveyed to the energy storage heat exchanger 22 through the first pipeline 41 for heat exchange and temperature rise. During the heat storage stage, if the booster pump 14 is in a shutdown state, the water supply pump 43 is started to convey the feed water to the energy storage heat exchanger 22 through the second pipeline 42 for heat exchange and temperature rise to ensure normal operation.

[0053] In some embodiments, the water supply unit 40 further includes a make-up water regulating valve 45. For example, one ends of the first pipeline 41 and the second pipeline 42 close to the energy storage heat exchanger 22 are commonly connected to the first end of the make-up water regulating valve 45, and the second end of the make-up water regulating valve 45 is connected to the energy storage heat exchanger 22. The make-up water regulating valve 45 is, for example, a pressure reducing valve, which can automatically maintain a stable outlet pressure by relying on the energy of the water itself. When the outlet pressure of the booster pump 14 or the water supply pump 43 is relatively high, it can be adjusted to a suitable pressure through the make-up water regulating valve 45 and then output to the energy storage heat exchanger 22.

[0054] In the foregoing embodiments, when the steam heating assembly 10 further includes a condensate recovery pipeline 16, the condensate generated after the steam is condensed by heat exchange with the steam user 15 is recovered to the water storage container 12. During the energy storage stage, a part of the feed water in the water storage container 12 flows into the energy storage heat exchanger 22 through the water supply unit 40, is heated into high-temperature water through the energy storage heat exchanger 22 and then output to the heat storage unit 23. The steam in the heat storage unit 23 enters the steam heating assembly 10 through the heat storage pressure maintaining flow path 32, and finally the condensate is recovered to the water storage container 12 through the condensate recovery pipeline 16. Thus, under the combined action of the water supply unit 40 and the heat storage pressure maintaining flow path 32, while the heat storage unit 23 is maintained at a constant pressure during the heat storage stage, part of the feed water is output from the water storage container 12 to the steam generating part 11 to generate steam through the steam heating assembly 10, and finally the steam is condensed and flows back to the water storage container 12 through the condensate recovery pipeline 16. This is more resource-saving compared to maintaining pressure with nitrogen or compressed air and does not affect the normal heating function of the steam heating assembly 10.

[0055] As Figure 6As shown, in a specific embodiment of the present invention, the steam heating assembly 10 includes a water storage container 12, a booster pump 14, a steam generator 111, a steam distributor 112, and a steam user 15 that are sequentially connected in a closed loop. The water storage container 12 is connected to the energy storage heat exchanger 22 via the water supply unit 40 and then to the heat storage unit 23 via the energy storage heat exchanger 22, forming a heat storage pipeline of the water storage and heat release assembly. An energy storage isolation valve 271 is provided on the heat storage pipeline. The heat storage unit 23 is connected to the water storage container 12 via the energy release circulation pump 26 and the energy release heat exchanger 24, forming a heat release pipeline of the water storage and heat release assembly. An energy release isolation valve 272 (specifically provided on the return water pipeline 28) is provided on the heat release pipeline, and a return water pressure reducing device 29 is also provided. The input end of the heat storage pressure maintaining flow path 32 is connected to the steam discharge port at the top of the heat storage unit 23, and the output end is connected to the steam distributor 112. The output end of the heat release pressure maintaining flow path 33 is connected to the steam inlet on the heat storage unit 23. After the input end of the steam input flow path is connected to the output end of the heat storage pressure maintaining flow path 32, it is connected to the steam distributor 112. A check valve 321 is provided on the heat storage pressure maintaining flow path 32, and a steam pressure reducing device 331 and a steam regulating valve 333 are provided on the heat release pressure maintaining flow path 33.

[0056] In the steam heating assembly 10, the booster pump 14 transports the water in the water storage container 12 to the steam generator 111. The steam generator 111 evaporates the water to generate water steam, which is then distributed by the steam distributor 112 to different steam users 15. The water steam condenses into condensate after passing through the steam user 15 and is recycled into the water storage container 12 to achieve circulating steam heating.

[0057] Before the start of the heat storage stage and after the end of the heat release stage, water steam is stored in the heat storage unit 23.

[0058] In the heat storage stage, the energy storage isolation valve 271 is opened, and the energy release isolation valve 272 is closed. The feed water in the water storage container 12 is transported to the energy storage heat exchanger 22 via the first pipeline 41 or the second pipeline 42 of the water supply unit 40. The feed water is heated to high-temperature water after heat exchange and enters the heat storage unit 23. The water level in the heat storage unit 23 rises, and the check valve 321 gradually opens. The water steam in the heat storage unit 23 enters the steam distributor 112 through the heat storage pressure maintaining flow path 32 for redistribution to maintain the pressure stability in the heat storage unit 23. In the heat storage stage, the pressure stability of the heat storage unit 23 and the cold storage unit 21 can be maintained through the heat storage pressure maintaining flow path 32 to ensure high-efficiency heat storage and safe operation.

[0059] During the heat release stage, the energy storage isolation valve 271 is closed and the energy release isolation valve 272 is opened. The high-temperature water in the heat storage unit 23 is transported to the energy release heat exchanger 24 by the energy release circulation pump 26. After the high-temperature water is cooled by heat exchange and depressurized by the return water pressure reducing device 29, it is output to the water storage container 12. As the water level in the heat storage unit 23 drops, the steam regulating valve 333 opens, and part of the water steam output from the steam distributor 112 is transported through the heat release pressure maintaining flow path 33. After being depressurized and cooled to an appropriate pressure and temperature by the steam pressure reducing device 331, it enters the heat storage unit 23 to maintain the pressure and temperature in the heat storage unit 23 and prevent safety problems such as water boiling and vaporization caused by the drop in water level, ensuring the safe operation of the system. When the liquid level in the heat storage unit 23 is zero, the heat release stage ends.

[0060] During the above heat storage stage or heat release stage, the interaction of feed water or water steam between the water heat storage and release component and the steam heating component can be realized through the heat storage pressure maintaining flow path 32 or the heat release pressure maintaining flow path 33, so as to maintain the pressure stability of the heat storage unit 23, ensure the safe operation of the system, and reduce the waste of resources.

[0061] The embodiment of the present invention also provides a control method for a pressure maintaining heat storage component with water as the medium, based on the pressure maintaining heat storage component with water as the heat exchange medium in any of the foregoing embodiments. The control heat release method includes:

[0062] Step S1: During the heat release stage, the heat release pressure maintaining flow path 33 transports part of the water steam output from the steam heating component 10 to the heat storage unit 23. The heat storage unit 23 outputs high-temperature water, and the volume of the water steam flowing into the heat storage unit 23 is equal to or greater than the volume of the high-temperature water flowing out of the heat storage unit 23, keeping the pressure in the heat storage unit 23 stable within the preset pressure range during the heat release stage. It can balance the water pressure change in the heat storage unit 23 caused by the output of high-temperature water.

[0063] Specifically, during the heat release stage, as the high-temperature water in the heat storage unit 23 flows out and the water level drops, water steam can be supplemented into the heat storage unit 23 through the heat release pressure maintaining flow path 33 to maintain the pressure in the heat storage unit 23 within the preset pressure range. It can prevent safety problems caused by the boiling and vaporization of high-pressure water due to the drop in the water level in the heat storage unit 23.

[0064] Specifically, when the pressure maintaining heat storage component with water as the heat exchange medium further includes a heat storage pressure maintaining flow path 32, the control method further includes step S2: During the heat storage stage, high-temperature water is input into the heat storage unit 23, and the water steam in the heat storage unit 23 is discharged to the steam heating component 10 through the heat storage pressure maintaining flow path 32. The volume of the high-temperature water entering and leaving the heat storage unit 23 is equal to or greater than the volume of the water steam discharged from the heat storage unit 23, so as to keep the pressure in the heat storage unit 23 stable within the preset pressure range during the heat storage stage. It can balance the water pressure change in the heat storage unit 23 caused by the input of high-temperature water.

[0065] Specifically, in the heat storage stage, the input of high-temperature water causes the water level in the heat storage unit 23 to rise. At this time, the water vapor in the heat storage unit 23 can enter the steam heating component 10 through the heat storage pressure-holding flow path 32, thereby maintaining the pressure in the heat storage unit 23 within the preset pressure range. Therefore, the provision of the heat storage pressure-holding flow path 32 in this embodiment can maintain pressure balance in the heat storage stage, prevent the pressure from exceeding the pressure-bearing limit of the equipment, and ensure safe and stable operation.

[0066] Steps S1 and S2 in the above control method can also be based on a water heat storage and release component including the aforementioned heat storage component. That is, the present invention also provides a control method for a water heat storage and release component, including the aforementioned steps S1 and S2.

[0067] The pressure-holding heat storage component using water as the heat exchange medium and its control method, and the water heat storage and release component and its control method provided in the above embodiments of the present invention can supplement water vapor to the heat storage unit 23 in the heat release stage through the heat release pressure-holding flow path 33 to maintain the pressure stability in the heat storage unit 23. Through the heat storage pressure-holding flow path 32, the water vapor in the heat storage unit 23 can be discharged to the steam heating component 10 in the heat storage stage to maintain the pressure stability in the heat storage unit 23 in the heat release stage. The heat energy can be reasonably utilized, ensuring safe and stable operation and reducing waste of resources.

[0068] The above is only a preferred embodiment of the present invention, and it does not impose any form of limitation on the present invention. Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to obtain equivalent embodiments with equivalent changes within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A pressure-holding heat storage component with water as the heat exchange medium, characterized in that, Comprising: A steam heating component, the steam heating component includes a steam generating part for evaporating feed water to generate water vapor; A heat storage unit for storing high-temperature water and water vapor; A heat release and pressure maintaining flow path, the input end of the heat release and pressure maintaining flow path is connected to the steam generating part, and the output end of the heat release and pressure maintaining flow path is connected to the heat storage unit; A heat storage and pressure maintaining flow path, the input end of the heat storage and pressure maintaining flow path is connected to the heat storage unit, and the output end of the heat storage and pressure maintaining flow path is connected to the steam generating part; In the heat release stage, the water vapor output by the steam generating part can be input into the heat storage unit through the heat release and pressure maintaining flow path, and the heat storage unit outputs the high-temperature water. The volume of the water vapor input into the heat storage unit is equal to or greater than the volume of the high-temperature water output from the heat storage unit, so as to keep the pressure of the heat storage unit stable within a preset pressure range in the heat release stage; In the heat storage stage, the heat storage unit inputs the high-temperature water, and the water vapor stored in the heat storage unit can be discharged to the steam generating part through the heat storage and pressure maintaining flow path; the volume of the high-temperature water input into the heat storage unit is equal to or greater than the volume of the water vapor discharged from the heat storage unit, so as to keep the pressure of the heat storage unit stable within the preset pressure range in the heat storage stage.

2. The pressure-maintaining heat storage component with water as the heat exchange medium according to claim 1, characterized in that The steam generating part includes a steam generator and a steam distributor. The steam generator is used to generate water vapor; the steam distributor is used to distribute the water vapor generated by the steam generator and then output it to the heat storage unit; the input end of the heat release and pressure maintaining flow path is connected to the steam distributor.

3. The pressure-maintaining heat storage component with water as the heat exchange medium according to claim 1, wherein A steam pressure reducing device is arranged on the heat release and pressure maintaining flow path, and the steam pressure reducing device is used to reduce the pressure of the water vapor input from the steam heating component to the preset pressure range and then output it to the heat storage unit.

4. The pressure-maintaining heat storage component using water as a heat exchange medium according to claim 1, wherein A check valve is arranged on the heat storage and pressure maintaining flow path, and the inlet end of the check valve is connected to the heat storage unit.

5. A water storage heat release component, characterized in that, Including the pressure maintaining heat storage component using water as the heat exchange medium according to any one of claims 1 to 4.

6. The water storage and heat release component according to claim 5, wherein, It further includes an energy release heat exchanger and a return water pipeline; the energy release heat exchanger is used to exchange heat and cool down the high-temperature water input from the heat storage unit and then output it in the heat release stage; the steam heating component further includes a water storage container for storing feed water; the input end of the return water pipeline is connected to the energy release heat exchanger, and the output end of the return water pipeline is connected to the water storage container; the return water pipeline is used to transport the water cooled down by the energy release heat exchanger to the water storage container.

7. The water storage and heat release component according to claim 6, characterized in that, A return water pressure reducing device is arranged on the return water pipeline, and the return water pressure reducing device is used to reduce the pressure of the water cooled down by the energy release heat exchanger and then output it to the water storage container.

8. The water storage and heat release component according to any one of claims 6 to 7, characterized in that The water heat storage and release component further includes a water supply unit and an energy storage heat exchanger; The water supply unit is connected between the water storage container and the energy storage heat exchanger, and the water supply unit is used to transport the feed water to the energy storage heat exchanger in the heat storage stage; The energy storage heat exchanger is connected to the heat storage unit; the energy storage heat exchanger is used to exchange heat and heat up the input feed water into high-temperature water and then output it to the heat storage unit in the heat storage stage.

9. A control method for a pressure-maintaining heat storage component with water as a heat exchange medium, characterized in that, Based on the pressure-holding heat storage component described in any one of claims 1 to 4, the control method includes: In the heat release stage, the heat release pressure-holding flow path conveys part of the water vapor generated by the steam generation part to the heat storage unit, and the heat storage unit outputs the high-temperature water. The volume of the water vapor flowing into the heat storage unit is equal to or greater than the volume of the high-temperature water flowing out of the heat storage unit, so as to keep the pressure of the heat storage unit stable within the preset pressure range in the heat release stage; in the heat storage stage, the heat storage unit inputs the high-temperature water, and the water vapor stored in the heat storage unit can be discharged to the steam generation part through the heat storage pressure-holding flow path; the volume of the high-temperature water input into the heat storage unit is equal to or greater than the volume of the water vapor discharged from the heat storage unit, so as to keep the pressure of the heat storage unit stable within the preset pressure range in the heat storage stage.

Images