Energy storage and release device using high-pressure water as heat storage medium and control method thereof

Abstract

The application discloses an energy storage and release device with high-pressure water as a heat storage medium and a control method thereof. The energy storage and release device comprises a first outlet of a first storage tank, a first control valve, a first water pump, a first heat exchange channel of a first heat exchanger, a first inlet of a second storage tank, a first outlet of the second storage tank, a first heat exchange channel of a second heat exchanger, a first inlet of the first storage tank, a second outlet of the first storage tank, a second heat exchange channel of the second heat exchanger, a second inlet of the second storage tank, a second outlet of the second storage tank, a third control valve, a second water pump, a first heat exchange channel of a third heat exchanger and a second inlet of the first storage tank. The application uses high-pressure water as a heat storage medium, and the pressure in the heat storage tank is maintained stable by supplementing the same pressure gas in the heat exchange process, so that the technical problem of the pressure fluctuation in the heat storage tank caused by using water as the heat storage medium can be solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of energy storage and release devices, and particularly relates to an energy storage and release device with high-pressure water as a heat storage medium and a control method thereof. BACKGROUND

[0002] The application of energy storage technology has solved the disadvantages of new energy generation volatility and intermittency to a great extent, and has effectively solved the technical problem of peak load shifting, and has been widely applied in recent years.

[0003] At present, the commonly used heat storage medium of the energy storage system mainly includes water, molten salt and heat conducting oil. The above three kinds of heat storage media have certain disadvantages in actual application. When the intermittent heat storage, heat release and heat storage temperature grade are low, the molten salt will solidify, causing pipeline blockage, which is not conducive to the safe and stable operation of the energy storage system. The heat conducting oil is suitable for a wide temperature range and can realize intermittent heat storage and heat release, but the heat conducting oil is flammable, resulting in low safety of the energy storage system, and the application field is also limited. Water as a heat storage medium has the advantages of clean and environmentally friendly, low cost, easy to obtain, large specific heat capacity and the like, and has been paid more and more attention at present.

[0004] In the prior art, since the heat storage tank is usually a constant volume container, as the heat storage water flows out of the heat storage tank to release heat, the heat storage water in the heat storage tank gradually decreases, the water pressure gradually decreases, the liquid water flashes into gas, causing the pressure in the heat storage tank to fluctuate greatly, thereby affecting the heat storage effect and system safety of the energy storage system. SUMMARY

[0005] The purpose of the present application is to provide an energy storage and release device with high-pressure water as a heat storage medium and a control method thereof to solve at least one of the above technical problems. In the technical solution provided by the present application, high-pressure water is used as a heat storage medium, and the same pressure gas is supplemented to maintain the stable pressure in the heat storage tank during heat exchange, which can solve the technical problem of the large fluctuation of the pressure in the heat storage tank caused by using water as a heat storage medium.

[0006] To achieve the above purpose, the following technical solutions are adopted in the present application:

[0007] The first aspect of the present application provides an energy storage and release device with high-pressure water as a heat storage medium, which comprises a first storage tank, a first heat exchanger, a second storage tank, a second heat exchanger and a third heat exchanger.

[0008] The first outlet of the first storage tank is connected to the first inlet of the second storage tank through the first heat exchange channel of the first heat exchanger, and the first outlet of the second storage tank is connected to the first inlet of the first storage tank through the first heat exchange channel of the second heat exchanger.

[0009] The second outlet of the first storage tank is connected with the second inlet of the second storage tank through the second heat exchange channel of the second heat exchanger, and the second outlet of the second storage tank is connected with the second inlet of the first storage tank through the first heat exchange channel of the third heat exchanger;

[0010] The first storage tank is used for storing high-pressure low-temperature water to be heat exchanged and high-pressure low-temperature gas after heat exchange, and the second storage tank is used for storing high-pressure high-temperature water after heat exchange and high-pressure high-temperature gas to be heat exchanged; wherein the high-pressure low-temperature water, the high-pressure low-temperature gas, the high-pressure high-temperature water and the high-pressure high-temperature gas have the same pressure, and the pressure is greater than or equal to the saturation pressure of the outlet water temperature of the first heat exchange channel of the first heat exchanger; the gas is a gas that is insoluble in water and does not react with water;

[0011] When the energy storage and release device stores energy, the high-pressure low-temperature water in the first storage tank enters the second storage tank after being cooled by the first heat exchanger, and the high-pressure high-temperature gas in the second storage tank enters the first storage tank after being heated by the second heat exchanger;

[0012] When the energy storage and release device releases energy, the high-temperature high-pressure water in the second storage tank enters the first storage tank after being cooled by the third heat exchanger, and the high-pressure low-temperature gas in the first storage tank enters the second storage tank after being heated by the second heat exchanger.

[0013] The further improvement of the energy storage and release device is that the energy storage and release subsystem further comprises:

[0014] The energy storage and release subsystem comprises a first pipeline channel, a second pipeline channel and a heat storage tank; the first pipeline channel is connected with the second pipeline channel and the heat storage tank in sequence through the third heat exchange channel of the second heat exchanger; the first pipeline channel is provided with a second control valve, and the second pipeline channel is provided with a fourth control valve;

[0015] When the energy storage and release subsystem stores energy, the medium of the energy storage and release subsystem enters the second heat exchanger after being cooled by the first pipeline channel, and then enters the heat storage tank through the second pipeline channel;

[0016] When the energy storage and release subsystem releases energy, the medium in the heat storage tank enters the second heat exchanger after being heated by the second pipeline channel, and then flows out through the first pipeline channel.

[0017] The further improvement of the energy storage and release device is that the medium used by the energy storage and release subsystem is normal-pressure air, and the first pipeline channel is connected with the atmosphere.

[0018] The further improvement of the energy storage and release device is that the temperature of the high-pressure high-temperature gas to be heat exchanged stored in the second storage tank is less than or equal to 150℃, and the medium used by the energy storage and release subsystem is water with a preset pressure;

[0019] Wherein, the preset pressure is greater than or equal to the saturation pressure at 150℃.

[0020] The further improvement of the energy storage and release device is that it further comprises a third pipeline channel and a fourth pipeline channel.

[0021] The inlet of the first heat exchange channel of the first heat exchanger is connected with the outlet of the first heat exchange channel of the first heat exchanger through the third pipeline channel, the fourth heat exchange channel of the second heat exchanger and the fourth pipeline channel in sequence.

[0022] The fifth control valve is arranged on the third pipeline channel or the fourth pipeline channel.

[0023] The further improvement of the energy storage and release device is that the second storage tank is further provided with an electric heating device for increasing the temperature of the high-pressure high-temperature gas to be heat exchanged in the second storage tank when the temperature of the gas is lower than a preset threshold temperature.

[0024] The further improvement of the energy storage and release device is that the energy storage and release device is used for storing heat at a temperature below 374℃.

[0025] The further improvement of the energy storage and release device is that, in the process of energy storage and release, the relationship between the flow of water and the flow of gas as working medium is,

[0026]

[0027] In the formula, m in represents the mass of the inlet gas of the first storage tank or the mass of the inlet water of the second storage tank, ρ in represents the density of the inlet gas of the first storage tank or the density of the inlet water of the second storage tank, m out represents the mass of the outlet water of the first storage tank or the mass of the outlet gas of the second storage tank, ρ out represents the density of the outlet water of the first storage tank or the density of the outlet gas of the second storage tank.

[0028] The further improvement of the energy storage and release device is that, in the process of energy storage and release, the first storage tank and the second storage tank are both reserved with a preset margin for water sealing.

[0029] The control method of the energy storage and release device with high-pressure water as heat storage medium provided by the application is used for the energy storage and release device of the first aspect of the application, and comprises the following steps:

[0030] In the energy storage process, if the high-pressure low-temperature water to be heat-exchanged in the first storage tank is input into the first heat exchanger to absorb heat, and the high-pressure high-temperature water after heat exchange is stored in the second storage tank, then the high-pressure high-temperature gas to be heat-exchanged in the second storage tank is input into the second heat exchanger to release heat, and the high-pressure low-temperature gas after heat exchange is stored in the first storage tank; wherein the pressure of the high-pressure low-temperature water, the high-pressure low-temperature gas, the high-pressure high-temperature water and the high-pressure high-temperature gas is the same, and is greater than or equal to the saturation pressure of the outlet water temperature of the first heat exchange channel of the first heat exchanger.

[0031] In the energy release process, if the high-pressure high-temperature water after heat exchange in the second storage tank is input into the third heat exchanger to release heat, and the high-pressure low-temperature water after heat exchange is stored in the first storage tank, then the high-pressure low-temperature gas in the first storage tank is input into the second heat exchanger to absorb heat, and the high-pressure high-temperature gas after heat exchange is stored in the second storage tank.

[0032] Compared with the prior art, the present application has the following beneficial effects:

[0033] In the energy storage and release device provided by the present application, high-pressure water is used as the heat storage medium, the high-pressure water in the first storage tank is discharged to perform heat exchange, and the same pressure gas is supplemented to maintain the pressure stability in the first storage tank, and the high-pressure low-temperature gas in the second storage tank is discharged to perform heat exchange, and the same pressure water is supplemented to maintain the pressure stability in the second storage tank, thereby solving the technical problem of the pressure fluctuation in the heat storage tank (such as the first storage tank and the second storage tank) caused by using water as the heat storage medium; the heat storage effect and system safety of the energy storage system can be improved while achieving flexible heat storage and release, and the device has the advantages of high heat storage efficiency, flexible and stable operation, high safety and the like; the high-pressure gas which is insoluble in water and does not react with water is used as the pressure maintaining working medium, the water pressure change during the operation of the device is very small or even unchanged, and the stability of the device is greatly improved.

[0034] In the present application, the energy storage and release subsystem is arranged to absorb the heat of the high-pressure gas in the heat storage process and heat the high-pressure gas in the heat release process; the temperature of the high-pressure gas is controlled to be close to the temperature of the high-pressure water in the heat storage and release process, so that the heat exchange between the high-pressure water and the high-pressure gas is prevented, the heat loss is reduced, and the heat storage efficiency of the device is effectively improved.

[0035] The control method of the present application can store the excess heat when the external heat is abundant, and release the heat when the external heat is scarce, so as to realize the full utilization of energy; the heat storage time and the working medium flow can be controlled to control the stored heat, so as to realize the full utilization of energy flexibly. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to make the technical solution of the embodiments of the present application or the prior art clearer, the drawings needed in the embodiments or prior art description will be briefly introduced as follows; obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0037] Figure 1 is a structural schematic diagram of an energy storage and release device provided by an embodiment of the present application, which uses high-pressure water as a heat storage medium;

[0038] Figure 2 is Figure 1 In the provided embodiment, the structural schematic diagram of the heat storage part is shown.

[0039] Figure 3 is Figure 1 In the provided embodiment, the structural schematic diagram of the heat release part is shown.

[0040] Figure 4 is a structural schematic diagram of a heat storage part in another embodiment of the present application;

[0041] Figures 1 to 4 In the above-mentioned embodiment, 1, first storage tank; 2, first water pump; 3, first heat exchanger; 4, second storage tank; 5, second heat exchanger; 6, heat storage tank; 7, second water pump; 8, third heat exchanger; 9, first control valve; 10, second control valve; 11, third control valve; 12, fourth control valve; 13, fifth control valve. DETAILED DESCRIPTION

[0042] In order to make the technical solution of the embodiments of the present application, the technical solution in the embodiments of the present application will be described clearly and completely by combining the drawings in the embodiments of the present application as follows; obviously, the described embodiments are only some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the present application.

[0043] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, unless the context clearly indicates otherwise. It will be further understood that the use of relational terms such as first and second, and the like are used solely to distinguish one from another entity without necessarily implying a relationship or order between these entities. Moreover, the terms "comprises", "comprising", and "including" and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, product, or apparatus that comprises a list of elements is not necessarily limited to those elements but can include other elements not expressly listed or inherent to such process, method, system, product, or apparatus.

[0044] The application will be further described in details below with reference to the accompanying drawings:

[0045] The energy storage and release device with high-pressure water as heat storage medium provided by the embodiment of the application comprises a first storage tank 1, a first heat exchanger 3, a second storage tank 4, a second heat exchanger 5 and a third heat exchanger 8.

[0046] The first outlet of the first storage tank 1 is connected to the first inlet of the second storage tank 4 through the first heat exchange channel of the first heat exchanger 3, and the first outlet of the second storage tank 4 is connected to the first inlet of the first storage tank 1 through the first heat exchange channel of the second heat exchanger 5.

[0047] The second outlet of the first storage tank 1 is connected to the second inlet of the second storage tank 4 through the second heat exchange channel of the second heat exchanger 5, and the second outlet of the second storage tank 4 is connected to the second inlet of the first storage tank 1 through the first heat exchange channel of the third heat exchanger 8.

[0048] The first storage tank 1 is used for storing high-pressure low-temperature water to be heat exchanged and high-pressure low-temperature gas after heat exchange, and the second storage tank 4 is used for storing high-pressure high-temperature water after heat exchange and high-pressure high-temperature gas to be heat exchanged. The pressure of the high-pressure low-temperature water, the high-pressure low-temperature gas, the high-pressure high-temperature water and the high-pressure high-temperature gas is the same, and is greater than or equal to the saturation pressure of the outlet water temperature of the first heat exchange channel of the first heat exchanger 3. The gas is a gas that is not soluble in water and does not react with water.

[0049] The control method of the energy storage and release device with high-pressure water as heat storage medium provided by the embodiment of the application comprises the following steps:

[0050] When storing energy, if the high-pressure low-temperature water to be heat-exchanged in the first storage tank 1 is input into the first heat exchanger 3 to absorb heat, the high-pressure high-temperature water after heat exchange is stored in the second storage tank 4, then the high-pressure high-temperature gas to be heat-exchanged in the second storage tank 4 is input into the second heat exchanger 5 to release heat, and the high-pressure low-temperature gas after heat exchange is stored in the first storage tank 1; wherein the pressure of the high-pressure low-temperature water, the high-pressure low-temperature gas, the high-pressure high-temperature water and the high-pressure high-temperature gas is the same, and is greater than or equal to the saturation pressure at the outlet water temperature of the first heat exchange channel of the first heat exchanger 3.

[0051] When releasing energy, if the high-pressure high-temperature water after heat exchange in the second storage tank 4 is input into the third heat exchanger 8 to release heat, the high-pressure low-temperature water after heat exchange is stored in the first storage tank 1, then the high-pressure low-temperature gas in the first storage tank 1 is input into the second heat exchanger 5 to absorb heat, and the high-pressure high-temperature gas after heat exchange is stored in the second storage tank 4.

[0052] In the embodiment of the present application, when the energy storage and release device stores energy, the high-pressure low-temperature water in the first storage tank 1 is heated by the first heat exchanger 3 and then enters the second storage tank 4, and the high-pressure high-temperature gas in the second storage tank 4 is cooled by the second heat exchanger 5 and then enters the first storage tank 1; when the energy storage and release device releases energy, the high-temperature high-pressure water in the second storage tank 4 is cooled by the third heat exchanger 8 and then enters the first storage tank 1, and the high-pressure low-temperature gas in the first storage tank 1 is heated by the second heat exchanger 5 and then enters the second storage tank 4. Specifically, in the energy storage and release device provided by the embodiment of the present application, high-pressure water is used as the heat storage medium, and the first storage tank and the second storage tank are provided, the high-pressure water in the first storage tank is supplemented with gas of the same pressure during the process of flowing out to maintain the pressure in the first storage tank stable, and the high-pressure low-temperature gas in the second storage tank is supplemented with water of the same pressure during the process of flowing out to maintain the pressure in the second storage tank stable, thereby solving the technical problem of the pressure in the heat storage tank fluctuating greatly caused by using water as the heat storage medium; further, the high-pressure gas which is insoluble in water and does not react with water is used as the pressure maintaining working medium in the present application, which can ensure that the water pressure changes little or even does not change during the operation of the device, thereby greatly improving the stability of the device.

[0053] Please refer to Figures 1 to 3 The energy storage and release device provided by the embodiment of the present application uses high-pressure water as the heat storage medium, and comprises a heat storage part and a heat release part.

[0054] The heat storage part specifically comprises a first storage tank 1 (i.e. a low-temperature storage tank, used for storing high-pressure water to be heated, the pressure of the high-pressure water should be greater than or equal to the saturation pressure at the outlet water temperature of the first heat exchange channel of the first heat exchanger 3, the high-pressure water in the first storage tank 1 is kept in liquid state, and the stable operation of the energy storage and release device is ensured), a first water pump 2, the first heat exchanger 3, a second storage tank 4 (i.e. a high-temperature storage tank, used for storing high-pressure gas which is insoluble in water and does not react with water, the pressure of the high-pressure gas is the same as that of the high-pressure water) and the first heat exchanger 3; the first outlet of the first storage tank 1 is connected to the inlet of the first water pump 2 through a first control valve 9, the outlet of the first water pump 2 is connected to the inlet of the first heat exchange channel of the first heat exchanger 3, the outlet of the first heat exchange channel of the first heat exchanger 3 is connected to the first inlet of the second storage tank 4, the first outlet of the second storage tank 4 is connected to the inlet of the first heat exchange channel of the second heat exchanger 5, and the outlet of the first heat exchange channel of the second heat exchanger 5 is connected to the first inlet of the first storage tank 1; the above components constitute the heat storage part of the entire energy storage and release device, and a specific example is shown in FIG. 1. Figure 2

[0055] The heat release part comprises the first storage tank 1, the second storage tank 4, the first heat exchanger 3, a second water pump 7 and a third heat exchanger 8; the second outlet of the first storage tank 1 is connected to the inlet of the second heat exchange channel of the second heat exchanger 5, the outlet of the second heat exchange channel of the second heat exchanger 5 is connected to the second inlet of the second storage tank 4, the second outlet of the second storage tank 4 is connected to the inlet of the second water pump 7 through a third control valve 11, the outlet of the second water pump 7 is connected to the inlet of the first heat exchange channel of the third heat exchanger 8, and the outlet of the first heat exchange channel of the third heat exchanger 8 is connected to the second inlet of the first storage tank 1; the above components constitute the heat release part of the entire energy storage system, and a specific example is shown in FIG. 2. Figure 3

[0056] The first storage tank 1 is provided with low-temperature water at a certain pressure, the second storage tank 4 is provided with high-temperature gas at the same pressure as the low-temperature water, and the high-pressure water is used as a heat storage medium for heat storage; when the first storage tank 1 outputs high-pressure low-temperature water for heat absorption, the high-pressure high-temperature gas output from the second storage tank 4 is supplemented to maintain the pressure of the first storage tank 1 stable. Further explanation, the high-pressure high-temperature gas output from the second storage tank 4 is supplemented to the first storage tank 1 after being cooled by the second heat exchanger 5, so as to prevent the high-pressure water from exchanging heat with the high-pressure gas and generating heat loss, and effectively improve the heat storage efficiency of the device.

[0057] ​​In one of the embodiments of the present application, the energy storage and release subsystem further comprises: a first pipeline channel, a second pipeline channel and a heat storage tank 6 (exemplarily, the heat storage tank can be a normal pressure heat storage tank); the first pipeline channel is connected with the second pipeline channel and the heat storage tank 6 in sequence via the third heat exchange channel of the second heat exchanger 5; the first pipeline channel is provided with a second control valve 10, and the second pipeline channel is provided with a fourth control valve 12. When the energy storage and release subsystem stores energy, the medium of the energy storage and release subsystem enters the second heat exchanger 5 to absorb heat and then enters the heat storage tank 6 via the second pipeline channel; when the energy storage and release subsystem releases energy, the medium in the heat storage tank 6 enters the second heat exchanger 5 to release heat and then flows out via the first pipeline channel.

[0058] In one of the embodiments, the medium used by the energy storage and release subsystem is normal pressure air, and the first pipeline channel is connected with the atmosphere. The energy storage and release subsystem is a normal pressure air heat storage subsystem, in which the atmosphere is connected to the inlet of the third heat exchange channel of the second heat exchanger 5 via the second control valve 10, and the outlet of the third heat exchange channel of the second heat exchanger 5 is connected to the inlet of the normal pressure heat storage tank 6; the outlet of the normal pressure heat storage tank 6 (exemplarily, the outlet can be the same as the inlet of the normal pressure heat storage tank 6, that is, the outlet and the inlet are combined into one) is connected to the outlet of the third heat exchange channel of the second heat exchanger 5 via the fourth control valve 12, and the inlet of the third heat exchange channel of the second heat exchanger 5 is connected to the atmosphere. In the alternative scheme of the embodiment of the present application, when the temperature of the gas in the second storage tank 4 is less than or equal to 150℃, the working medium of the normal pressure air heat storage subsystem can be replaced by water with a certain pressure, which can greatly reduce the volume of the normal pressure heat storage tank 6; the pressure of the water in the normal pressure heat storage tank 6 should be greater than or equal to the saturation pressure of 150℃, so as to keep the water in the normal pressure heat storage tank 6 in liquid state.

[0059] In the embodiment of the present application, the normal pressure air heat storage subsystem is provided to absorb the heat of the high pressure gas during the heat storage process and heat the high pressure gas during the heat release process, so as to control the temperature of the high pressure gas to be close to the temperature of the high pressure water during the heat storage and release processes, prevent the heat exchange between the high pressure water and the high pressure gas and generate heat loss, and effectively improve the heat storage efficiency of the device.

[0060] Please refer to Figure 4In the embodiment of the present application, the third pipeline channel and the fourth pipeline channel are further included; the fifth control valve 13 is arranged on the third pipeline channel or the fourth pipeline channel; the inlet of the first heat exchange channel of the first heat exchanger 3 is connected to the outlet of the first heat exchange channel of the first heat exchanger 3 in sequence through the third pipeline channel, the fourth heat exchange channel of the second heat exchanger 5 and the fourth pipeline channel; during the heat storage process, the fifth control valve 13 is opened, and part of the high-pressure water output by the first water pump 2 enters the second heat exchanger 5 to exchange heat with the gas output by the second storage tank 4, and then flows into the outlet of the first heat exchange channel of the first heat exchanger 3 and enters the second storage tank 4 for storage. Figure 1 In the embodiment shown, the heat exchange medium of the second heat exchanger 5 is all air at normal temperature and pressure, and after the air at normal temperature and pressure exchanges heat with the high-temperature and high-pressure gas initially stored in the second storage tank 4 through the second heat exchanger 5, the air is all stored in the heat storage tank 6; in the improved device of the embodiment of the present application, part of the heat exchange medium flowing through the second heat exchanger 5 comes from the high-pressure and low-temperature water from the first storage tank 1 (part of the high-pressure and low-temperature water exchanges heat with the high-temperature and high-pressure gas initially stored in the second storage tank 4 through the second heat exchanger 5 and is stored in the second storage tank 4), and part of the heat exchange medium comes from air at normal temperature and pressure (part of the air at normal temperature and pressure exchanges heat with the high-temperature and high-pressure gas initially stored in the second storage tank 4 through the second heat exchanger 5 and is stored in the heat storage tank 6), which can reduce the amount of air required by the air storage subsystem at normal pressure (i.e., the amount of air that exchanges heat with all the high-temperature and high-pressure gas initially stored in the second storage tank 4), reduce the volume of the heat storage tank 6, and effectively reduce the cost of the energy storage and release device.

[0061] In the further preferred technical solution of the embodiment of the present application, the second storage tank 4 is further provided with an electric heating device for increasing the temperature of the high-pressure and high-temperature gas to be heat exchanged in the second storage tank 4 when the temperature of the gas is lower than a preset threshold temperature. Specifically, when the temperature of the gas in the tank is relatively low at the beginning of the heat storage process, the electric heating device is turned on to increase the temperature of the gas, so as to reduce the heat exchange when the high-pressure water after absorbing external heat enters the tank, thereby ensuring the stable operation of the device and effectively improving the heat storage efficiency of the device.

[0062] In the above technical solution provided by the embodiment of the present application, the high-pressure gas insoluble in water is used to stabilize the water pressure of the heat storage tank 6, which can realize flexible storage and release of heat while improving the heat storage effect of the energy storage system and the safety of the system, and has the advantages of high heat storage efficiency, flexible and stable operation, high safety, etc. Further specifically, the high-pressure water is used as the heat storage medium, which can remain in liquid state at any temperature to ensure the stability of the device; at the same time, water is non-toxic and non-flammable, which can effectively improve the safety of the device; the high-pressure gas insoluble in water is used as the pressure maintaining working medium in the present application, which can ensure that the water pressure changes little or even remains unchanged during the operation of the device, greatly improving the stability of the device.

[0063] The control method of the energy storage and release device with high-pressure water as the heat storage medium provided by the embodiment of the present application specifically comprises the following steps:

[0064] In the initial state, all the four control valves are closed; the first storage tank 1 is filled with low-temperature water with a certain pressure, and the second storage tank 4 is filled with high-temperature gas with the same pressure as the low-temperature water.

[0065] When there is abundant heat from the outside, the first control valve 9 and the second control valve 10 are opened, and the third control valve 11 and the fourth control valve 12 are closed, so that the heat storage part works; the low-temperature water with pressure in the first storage tank 1 is pressurized by the first water pump 2 (to overcome the resistance along the way) and then enters the first heat exchanger 3 to absorb heat from the outside, and the water that is heated by absorbing heat enters the second storage tank 4 for storage; the high-temperature and high-pressure gas initially stored in the second storage tank 4 enters the second heat exchanger 5 to release heat and be cooled, and the cooled gas enters the first storage tank 1, so as to prevent the high-pressure water in the first storage tank 1 from flowing out and causing the formation of a vacuum in the tank and thus leading to the fluctuation of the pressure in the tank; thus, the heat storage is completed.

[0066] When there is insufficient heat from the outside, the third control valve 11 and the fourth control valve 12 are opened, and the first control valve 9 and the second control valve 10 are closed, so that the heat release part works; the high-temperature and high-pressure water in the second storage tank 4 is pressurized by the second water pump 7 (to overcome the resistance along the way) and then enters the third heat exchanger 8 to release heat and be cooled, and the low-temperature and high-pressure water that is cooled enters the first storage tank 1 for storage; the low-temperature and high-pressure gas in the first storage tank 1 enters the second heat exchanger 5 to exchange heat and be heated, and the heated gas enters the second storage tank 4, so as to prevent the high-pressure water in the second storage tank 4 from flowing out and causing the formation of a vacuum in the tank and thus leading to the fluctuation of the pressure in the tank; thus, the heat release is completed.

[0067] In the embodiment of the present application, the normal-pressure air heat storage subsystem participates in the heat storage and release processes simultaneously; in the heat storage process, the air at normal temperature and pressure enters the second heat exchanger 5 to absorb heat and be heated, and the heated air enters the normal-pressure heat storage tank 6 for storage; in the heat release process, the high-temperature air in the normal-pressure heat storage tank 6 enters the second heat exchanger 5 to release heat, and the cooled air is discharged to the atmosphere.

[0068] The control method of the present application can store the excess heat when there is abundant heat from the outside and release the heat when there is insufficient heat from the outside, so as to realize the full utilization of energy. The present application can control the capacity by controlling the heat storage and release time and the working fluid flow, so as to flexibly realize the full utilization of energy.

[0069] In the specific example of the embodiment of the present application, the high-pressure gas in the second storage tank 4 is selected to be a gas that is difficult to dissolve in water, such as nitrogen, noble gas, etc., so as to ensure that the pressure of the water and the gas remains stable.

[0070] Preferably, in the embodiment of the present application, the first storage tank 1 and the second storage tank 4 should reserve a certain margin for water sealing. Whether it is a heat storage process or a heat release process, the tank must reserve a certain amount of water that can seal high-pressure gas.

[0071] In the embodiment of the present application, the relationship between the water and gas flow as working medium can be,

[0072] In the formula, m in represents the mass of the inlet gas of the first storage tank or the mass of the inlet water of the second storage tank, ρ in represents the density of the inlet gas of the first storage tank or the density of the inlet water of the second storage tank, m out represents the mass of the outlet water of the first storage tank or the mass of the outlet gas of the second storage tank, ρ out represents the density of the outlet water of the first storage tank or the density of the outlet gas of the second storage tank.

[0073] The above formula is applicable to any tank in any process, and the specific parameters should be determined according to the actual situation; for example, in the heat storage process, the relationship between the water and gas in the second storage tank is,

[0074] In the formula, m water represents the mass of the water entering the second storage tank, m gas represents the mass of the high-pressure gas stored in the second storage tank, ρ water_hot represents the density of the water after being heated and warmed up by the first heat exchanger, ρ gas_stor represents the density of the high-pressure gas stored in the second storage tank.

[0075] The exemplary application scenario of the technical solution in the embodiment of the present application can be coupled with a gas-liquid phase change carbon dioxide energy storage system; the first heat exchanger and the third heat exchanger can be replaced by the energy storage heat exchanger and the energy release heat exchanger of Chinese invention patent authorized publication numbers CN112985143B, CN112985144B and CN112985145B.

[0076] In the embodiment of the present application, the pressure of the pressurized water depends on the temperature corresponding to the external excess heat, and the pressure of the pressurized water should satisfy that the water remains in a liquid state after being heated and warmed up by the first heat exchanger; for example, when the temperature of the external excess heat is 200℃, the pressure of the pressurized water should be no less than 1555kPa; when the temperature of the external excess heat is 300℃, the pressure of the pressurized water should be no less than 8588kPa; in addition, the temperature of the external excess heat should be no more than 374℃.

[0077] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit it. Although the present application has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and any modification or equivalent replacement should be covered in the protection scope of the claims of the present application.

Claims

1. An energy storage and release device using high-pressure water as the heat storage medium, characterized in that, include: First storage tank (1), first heat exchanger (3), second storage tank (4), second heat exchanger (5) and third heat exchanger (8); The first outlet of the first storage tank (1) is connected to the first inlet of the second storage tank (4) through the first heat exchange channel of the first heat exchanger (3), and the first outlet of the second storage tank (4) is connected to the first inlet of the first storage tank (1) through the first heat exchange channel of the second heat exchanger (5). The second outlet of the first storage tank (1) is connected to the second inlet of the second storage tank (4) via the second heat exchange channel of the second heat exchanger (5), and the second outlet of the second storage tank (4) is connected to the second inlet of the first storage tank (1) via the first heat exchange channel of the third heat exchanger (8). Wherein, the first storage tank (1) is used to store the high-pressure low-temperature water to be heat exchanged and the high-pressure low-temperature gas after heat exchange, and the second storage tank (4) is used to store the high-pressure high-temperature water after heat exchange and the high-pressure high-temperature gas to be heat exchanged; wherein, the high-pressure low-temperature water, the high-pressure low-temperature gas, the high-pressure high-temperature water and the high-pressure high-temperature gas have the same pressure, and all are greater than or equal to the saturation pressure at the outlet water temperature of the first heat exchange channel of the first heat exchanger (3); the gas is a gas that is insoluble in water and does not react with water; When the energy storage and release device stores energy, the high-pressure low-temperature water in the first storage tank (1) absorbs heat through the first heat exchanger (3) and then enters the second storage tank (4). The high-pressure high-temperature gas in the second storage tank (4) releases heat through the second heat exchanger (5) and then enters the first storage tank. When the energy storage and release device releases energy, the high-temperature and high-pressure water in the second storage tank (4) releases heat through the third heat exchanger (8) and then enters the first storage tank (1). The high-pressure and low-temperature gas in the first storage tank (1) absorbs heat through the second heat exchanger (5) and then enters the second storage tank (4). It also includes: energy storage and release subsystems; The energy storage and release subsystem includes a first pipeline channel, a second pipeline channel, and a heat storage tank (6); the first pipeline channel is connected to the heat storage tank (6) in sequence via the third heat exchange channel of the second heat exchanger (5) and the second pipeline channel; the first pipeline channel is equipped with a second control valve (10), and the second pipeline channel is equipped with a fourth control valve (12). When the energy storage and energy release subsystem stores energy, the medium of the energy storage and energy release subsystem enters the second heat exchanger (5) through the first pipeline channel to absorb heat, and then enters the heat storage tank (6) through the second pipeline channel. When the energy storage and release subsystem releases energy, the medium in the heat storage tank (6) enters the second heat exchanger (5) through the second pipeline channel to release heat, and then flows out through the first pipeline channel.

2. The energy storage and release device using high-pressure water as the heat storage medium according to claim 1, characterized in that, The energy storage and release subsystem uses atmospheric pressure air as the medium, and the first pipeline channel is connected to the atmosphere.

3. The energy storage and release device using high-pressure water as the heat storage medium according to claim 1, characterized in that, The temperature of the high-pressure, high-temperature gas to be heat exchanged stored in the second storage tank (4) is less than or equal to 150°C, and the medium used in the energy storage and release subsystem is water with a preset pressure. The preset pressure is greater than or equal to the saturation pressure at a temperature of 150°C.

4. The energy storage and release device using high-pressure water as the heat storage medium according to claim 1, characterized in that, Also includes: The third and fourth pipeline channels; The inlet of the first heat exchange channel of the first heat exchanger (3) is connected to the outlet of the first heat exchange channel of the first heat exchanger (3) in sequence through the third pipeline channel, the fourth heat exchange channel of the second heat exchanger (5), and the fourth pipeline channel. A fifth control valve (13) is provided on the third or fourth pipeline channel.

5. The energy storage and release device using high-pressure water as the heat storage medium according to claim 1, characterized in that, The second storage tank (4) is also equipped with an electric heating device, which is used to raise the gas temperature when the temperature of the high-pressure high-temperature gas to be heat exchanged stored in the second storage tank (4) is lower than the preset threshold temperature.

6. The energy storage and release device using high-pressure water as the heat storage medium according to claim 1, characterized in that, The energy storage and release device is used to store heat at a temperature below 374°C.

7. An energy storage and release device using high-pressure water as the heat storage medium according to any one of claims 1 to 6, characterized in that, During energy storage and release, the relationship between the flow rates of water and gas, used as working fluids, is as follows: ； In the formula, m in This indicates the quality of the inlet gas in the first storage tank or the quality of the inlet water in the second storage tank. ρ in This indicates the inlet gas density of the first storage tank or the inlet water density of the second storage tank. m out This indicates the outlet water quality of the first storage tank or the outlet gas quality of the second storage tank. ρ out This indicates the outlet water density of the first storage tank or the outlet gas density of the second storage tank.

8. An energy storage and release device using high-pressure water as the heat storage medium according to any one of claims 1 to 6, characterized in that, During the energy storage and release process, both the first storage tank (1) and the second storage tank (4) have a pre-set margin for water sealing.

9. A control method for an energy storage and release device using high-pressure water as the heat storage medium, used in any one of claims 1 to 8, characterized in that, Includes the following steps: During energy storage, if the high-pressure low-temperature water to be heat-exchanged in the first storage tank (1) is input into the first heat exchanger (3) to absorb heat, and the high-pressure high-temperature water after heat exchange is stored in the second storage tank (4), then the high-pressure high-temperature gas to be heat-exchanged in the second storage tank (4) is input into the second heat exchanger (5) to release heat, and the high-pressure low-temperature gas after heat exchange is stored in the first storage tank (1); wherein, the pressure of the high-pressure low-temperature water, the high-pressure low-temperature gas, the high-pressure high-temperature water and the high-pressure high-temperature gas are the same, and all are greater than or equal to the saturation pressure at the outlet water temperature of the first heat exchange channel of the first heat exchanger (3); When releasing energy, if the high-pressure high-temperature water in the second storage tank (4) after heat exchange is input into the third heat exchanger (8) to release heat, and the high-pressure low-temperature water after heat exchange is stored in the first storage tank (1), then the high-pressure low-temperature gas in the first storage tank (1) is input into the second heat exchanger (5) to absorb heat, and the high-pressure high-temperature gas after heat exchange is stored in the second storage tank (4).

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