Heat storage system for synchronously storing sensible heat of heat pump and latent heat of phase change and operation method of heat storage system

Abstract

The invention relates to the technical field of heat storage, and discloses a heat storage system for synchronously storing sensible heat and phase change latent heat of a heat pump and an operation method of the heat storage system. In the system, a heat pump overheating section heat exchanger and a heat pump two-phase section heat exchanger are sequentially arranged corresponding to an organic working medium heat release loop of the heat pump and are used for producing high-temperature hot water and water vapor; a first water pump is arranged on the high-temperature hot water loop; a second water pump is arranged on the water vapor loop; the heat storage device comprises a plurality of heat storage modules, a plurality of three-way valves are arranged on the heat storage modules, the heat pump overheating section heat exchanger communicates with the three-way valves of the heat storage modules through a high-temperature hot water loop, and the heat pump two-phase section heat exchanger is connected with the three-way valves of the heat storage modules through a water vapor loop. The heat pump overheating section heat exchanger is connected with the high-temperature hot water buffer tank through a high-temperature hot water loop, and the heat pump two-phase section heat exchanger is connected with the water vapor buffer tank through a water vapor loop. Synchronous composite heat storage of the high-temperature heat pump system capable of generating water vapor can be achieved.

Description

Technical Field

[0001] The present application relates to the field of heat storage technology, and in particular to a heat storage system for synchronously storing sensible heat and latent heat of a heat pump and an operating method thereof. Background Art

[0002] Energy storage technology plays a key role in solving the problem of mismatch between energy supply and demand. Heat storage technology can not only be scaled up technically and economically, but also has the advantages of high energy density, long life, diverse utilization methods and high comprehensive thermal utilization efficiency.

[0003] For heat storage systems, there are sensible heat storage, phase change heat storage and thermochemical heat storage. Among them, sensible heat storage technology is mature and simple to operate. It is one of the most widely used heat storage methods. Low-cost sensible heat storage methods often use concrete, rock or pressurized water to store or release heat by raising or lowering the temperature of the material, but its heat storage density is low, thermal conductivity is poor, there are significant temperature fluctuations, and some also require pressurization; phase change heat storage has the advantages of high energy density and nearly constant temperature during the phase change process, but the latent heat phase change of solid-liquid phase change is extremely small compared to the heat stored by single-phase heat storage materials through large temperature differences. For example, the latent heat of common nitrate heat storage materials is only 100-120 J / g, and some mixed molten salts may be lower.

[0004] If the molten salt phase change material is first used to store latent heat, and then the sensible heat is used to store heat after the molten salt is completely melted, this coupled storage of latent and sensible heat greatly increases the energy density of molten salt thermal storage. This storage method of storing sensible heat first and then latent heat has been proposed in a patent, namely "Sensible Heat Storage and Latent Heat Storage Coupled Thermal Storage Steam Supply System and Operation Method" (CN 115854314A).

[0005] However, the above-mentioned patent cannot be used for heat pump heat storage, because the heat pump produces latent heat and sensible heat simultaneously, and the above-mentioned patent can only start storing sensible heat after the molten salt is completely melted, that is, after the latent heat storage is completed.

[0006] Therefore, the present application proposes a synchronous composite heat storage method for a high-temperature heat pump system producing water vapor, which can simultaneously store the latent heat of water vapor produced by the heat pump and the sensible heat (high-temperature hot water) of the heat pump. Summary of the Invention

[0007] The purpose of the present application is to provide a heat storage system that synchronously stores sensible heat and latent heat of a heat pump, so as to realize synchronous composite heat storage of a high-temperature heat pump system that produces water vapor.

[0008] In order to achieve the above purpose, the technical solutions adopted are as follows:

[0009] In a first aspect, the present application provides a heat storage system for simultaneously storing sensible heat and latent heat of a heat pump, comprising:

[0010] The heat exchanger in the superheating section of the heat pump corresponds to the heat release circuit of the organic working fluid of the heat pump and is used to produce high-temperature hot water;

[0011] The heat pump two-phase heat exchanger is set corresponding to the heat pump's organic working fluid heat release circuit and is used to produce water vapor;

[0012] A high-temperature hot water circuit, wherein a first water pump is provided on the high-temperature hot water circuit;

[0013] a water vapor circuit, wherein a second water pump is provided on the water vapor circuit;

[0014] The heat storage device includes a plurality of heat storage modules, each of which is provided with a plurality of three-way valves. The heat pump superheating section heat exchanger is connected to the three-way valve of each heat storage module through the high-temperature hot water circuit, and the heat pump two-phase section heat exchanger is connected to the three-way valve of each heat storage module through the water vapor circuit;

[0015] High-temperature hot water buffer tank, the heat pump superheating section heat exchanger is connected to the high-temperature hot water buffer tank through the high-temperature hot water circuit,

[0016] A water vapor buffer tank, wherein the heat pump two-phase heat exchanger is connected to the water vapor buffer tank through the water vapor loop.

[0017] Preferably, in the above-mentioned heat storage system for simultaneously storing sensible heat of the heat pump and latent heat of phase change, four three-way valves are provided on the heat storage module, namely a first three-way valve, a second three-way valve, a third three-way valve and a fourth three-way valve.

[0018] Preferably, in the above-mentioned heat storage system for synchronously storing sensible heat and latent heat of phase change of the heat pump, the high-temperature hot water circuit includes a first pipe and a second pipe, one end of the first pipe is connected to the first port of the heat pump superheating section heat exchanger, and the other end thereof is connected in sequence to the second three-way valve of each of the heat storage modules and then to the water inlet end of the high-temperature hot water buffer tank, one end of the second pipe is connected to the water outlet end of the high-temperature hot water buffer tank, and the other end thereof is connected in sequence to the third three-way valve of each of the heat storage modules and then to the second port of the heat pump superheating section heat exchanger.

[0019] Preferably, in the above-mentioned heat storage system for synchronously storing sensible heat and latent heat of phase change of the heat pump, the water vapor circuit includes a third pipe and a fourth pipe, one end of the third pipe is connected to the first port of the heat pump two-phase section heat exchanger, and the other end thereof is connected in sequence to the first three-way valve of each of the heat storage modules and then to the water inlet end of the water vapor buffer tank, one end of the fourth pipe is connected to the water outlet end of the water vapor buffer tank, and the other end thereof is connected in sequence to the fourth three-way valve of each of the heat storage modules and then to the second port of the heat pump two-phase section heat exchanger.

[0020] Preferably, in the above-mentioned heat storage system for simultaneously storing sensible heat and latent heat of the heat pump, a molten salt heat storage medium is provided in each of the heat storage modules, and the molten salt heat storage medium is nitrate, chloride or carbonate, and the nitrate is sodium nitrate, potassium nitrate, sodium nitrite and a mixture thereof.

[0021] Preferably, the above-mentioned heat storage system for synchronously storing sensible heat and latent heat of the heat pump further includes a controller, and the controller is signal-connected to the first water pump, the second water pump and several three-way valves provided on the heat storage module.

[0022] In a second aspect, the present application provides a method for operating a heat storage system for synchronously storing sensible heat and latent heat of a heat pump as described above, the method comprising:

[0023] Adjusting all three-way valves provided on each heat storage module to an initial state, in which the high-temperature hot water circuit and the water vapor circuit are disconnected from each heat storage module, and the heat pump superheating section heat exchanger and the heat pump two-phase section heat exchanger are connected to the high-temperature hot water buffer tank and the water vapor buffer tank respectively through the high-temperature hot water circuit and the water vapor circuit;

[0024] Adjusting the three-way valve of the first heat storage module so that the first heat storage module is connected to the heat pump two-phase heat exchanger through the water vapor circuit, and utilizing the water vapor generated by the heat pump two-phase heat exchanger to perform latent heat storage in the first heat storage module;

[0025] After the first heat storage module completes latent heat storage, the three-way valve of the first heat storage module is adjusted so that the first heat storage module is connected to the heat pump superheating section heat exchanger through the high-temperature hot water circuit, and the high-temperature hot water generated by the heat pump superheating section heat exchanger is used to perform sensible heat storage in the first heat storage module until the heat storage temperature of the heat storage module reaches the target temperature, and the three-way valve of the first heat storage module is reset. After the first heat storage module completes latent heat storage, the three-way valve of the first heat storage module is adjusted, and at the same time, the three-way valve of the second heat storage module is adjusted so that the second heat storage module is connected to the heat pump two-phase section heat exchanger through the water vapor circuit, and the water vapor generated by the heat pump two-phase section heat exchanger is used to perform latent heat storage in the second heat storage module;

[0026] According to the above steps, each heat storage module is controlled in sequence in a cycle until all heat storage modules have completed heat storage.

[0027] Preferably, in the above operating method, if the heat storage medium in the first heat storage module is completely dissolved, it is determined that the latent heat storage of the first heat storage module is completed.

[0028] The beneficial effects of this application are:

[0029] This application utilizes multiple heat storage modules to store heat, and through the coordination of pipelines and valves, it achieves the simultaneous storage of sensible heat and latent heat of high-temperature heat pumps. Compared with the single phase change heat storage or single phase heat storage form, it reduces the heat storage temperature difference and reduces the heat storage time. loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic structural diagram of a heat storage system for synchronously storing sensible heat and latent heat of a heat pump according to an embodiment of the present application is shown.

[0031] Figure 2 A flow chart of an operating method of a heat storage system for synchronously storing sensible heat and latent heat of a heat pump according to an embodiment of the present application is shown.

[0032] Figure 3 A partial flow chart of an operating method of a heat storage system for synchronously storing sensible heat of a heat pump and latent heat of phase change according to an embodiment of the present application is shown.

[0033] Reference numerals:

[0034] 101. Heat pump superheat section heat exchanger; 102. Heat pump two-phase section heat exchanger;

[0035] 201, high-temperature hot water circuit; 2011, first pipeline; 2012, second pipeline; 202, steam circuit; 2021, third pipeline; 2022, fourth pipeline;

[0036] 301, first heat storage module; 3011, first three-way valve of the first heat storage module; 3012, second three-way valve of the first heat storage module; 3013, third three-way valve of the first heat storage module; 3014, fourth three-way valve of the first heat storage module;

[0037] 302, the second heat storage module; 3021, the first three-way valve of the second heat storage module; 3022, the second three-way valve of the second heat storage module; 3023, the third three-way valve of the second heat storage module; 3024, the fourth three-way valve of the second heat storage module;

[0038] 30X, the second heat storage module; 30X1, the first three-way valve of the Xth heat storage module; 30X2, the second three-way valve of the Xth heat storage module; 30X3, the third three-way valve of the Xth heat storage module; 30X4, the fourth three-way valve of the Xth heat storage module;

[0039] 401, first water pump; 402, second water pump;

[0040] 5. Organic working fluid heat release circuit;

[0041] 601. High-temperature hot water buffer tank; 602. Steam buffer tank;

[0042] 701, high temperature hot water interface; 702, water steam interface. DETAILED DESCRIPTION

[0043] The following describes the embodiments of the present application through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other unless they conflict.

[0044] The specific implementation of the present application is further described in detail below with reference to the accompanying drawings and examples.

[0045] Example 1:

[0046] The present application provides a heat storage system for synchronously storing sensible heat and latent heat of a heat pump. Figure 1 As shown, the heat storage system for synchronously storing the sensible heat and latent heat of the heat pump includes a heat pump superheating section heat exchanger 101, a heat pump two-phase section heat exchanger 102, a high-temperature hot water circuit 201, a water vapor circuit 202, a heat reservoir, a high-temperature hot water buffer tank 601 and a water vapor buffer tank 602. The heat pump superheating section heat exchanger 101 and the heat pump two-phase section heat exchanger 102 are respectively arranged corresponding to the organic working fluid heat release circuit 5 of the heat pump to produce high-temperature hot water and water vapor; a first water pump 401 is arranged on the high-temperature hot water circuit 201, and a second water pump 402 is arranged on the water vapor circuit 202; the heat reservoir includes multiple heat storage modules, Figure 1The figure shows the first heat storage module 301, the second heat storage module 302 and the Xth heat storage module 30X. The heat storage module 302 is provided with several three-way valves. The heat pump superheating section heat exchanger 101 is connected to the three-way valves of each heat storage module through the high-temperature hot water circuit 201, and the heat pump two-phase section heat exchanger is connected to the three-way valves of each heat storage module through the water vapor circuit; the heat pump superheating section heat exchanger 101 is connected to the high-temperature hot water buffer tank 601 through the high-temperature hot water circuit 201, and the heat pump two-phase section heat exchanger 102 is connected to the water vapor buffer tank 602 through the water vapor circuit 202.

[0047] The heat pump starts, and its organic working fluid circulates in the organic working fluid heat release loop 5. The organic working fluid heat release loop 5 releases sensible heat from the superheating section and latent heat from the two-phase section through heat exchangers 101 and 102, respectively. This causes the heat pump's superheating section heat exchanger 101 and the heat pump's two-phase section heat exchanger 102 to produce high-temperature hot water and steam, respectively. The high-temperature hot water is at a higher temperature than the steam. A first water pump 401 drives the flow of high-temperature hot water in the high-temperature hot water loop 201. In the steam loop 202, the steam condenses, storing latent heat in the heat storage module. The condensed water then flows back. A second water pump 402 provides the power for this condensed water return. During heat storage, the steam in the steam loop 202 can first be used to store latent heat in the heat storage medium in the first heat storage module 301. After latent heat storage is complete, the three-way valve is adjusted to store latent heat in the second heat storage module 302. This process continues for X number of heat storage modules. At the same time, after the latent heat storage of the heat storage medium in the first heat storage module 301 is completed, sensible heat storage is also performed using the high-temperature hot water in the high-temperature hot water circuit 201. This process can be performed simultaneously with the latent heat storage in the second heat storage module 302, and the cycle continues until all heat storage modules have completed heat storage. The process of storing heat in each heat storage module using high-temperature hot water and water vapor utilizes a non-contact method, for example, through heat exchange piping within each heat storage module. Both the high-temperature hot water buffer tank 601 and the water vapor buffer tank 602 act as buffers. For example, excess high-temperature hot water enters the high-temperature hot water buffer tank 601 for storage, and excess steam enters the water vapor buffer tank 602 for storage. When the heat storage modules are switched or demand changes, the high-temperature hot water buffer tank 601 and the water vapor buffer tank 602 can provide or absorb the medium to stabilize the system pressure and flow.

[0048] In some embodiments, the heat storage module is provided with four three-way valves, namely a first three-way valve, a second three-way valve, a third three-way valve and a fourth three-way valve. Figure 1The four three-way valves of the first heat storage module 301 are the first three-way valve 3011, the second three-way valve 3012, the third three-way valve 3013, and the fourth three-way valve 3014 of the first heat storage module. The second three-way valve 3012 and the third three-way valve 3013 of the first heat storage module serve as the inlet and outlet of high-temperature hot water, while the first three-way valve 3011 and the fourth three-way valve 3014 of the first heat storage module serve as the inlet and outlet of water vapor. The same applies to the second heat storage module 302 and the Xth heat storage module 30X. The above notations are merely provided to pave the way for the subsequent operation method, so that those skilled in the art can fully understand the technical solutions proposed in this application.

[0049] In some embodiments, as Figure 1 As shown, the high-temperature hot water circuit 201 includes a first pipe 2011 and a second pipe 2012. One end of the first pipe 2011 is connected to the first port of the heat exchanger 101 of the superheating section of the heat pump, and the other end thereof is connected in sequence to the second three-way valve of each heat storage module and then to the water inlet end of the high-temperature hot water buffer tank 601. One end of the second pipe 2012 is connected to the water outlet end of the high-temperature hot water buffer tank 601, and the other end thereof is connected in sequence to the third three-way valve of each heat storage module and then to the second port of the heat exchanger 101 of the superheating section of the heat pump.

[0050] The first port of the heat pump superheating section heat exchanger 101 outputs high-temperature hot water, which can be transported to a heat storage module through the first pipe 2011. After heat exchange, the high-temperature hot water returns to the heat pump superheating section heat exchanger 101 through the second port of the heat pump superheating section heat exchanger 101 through the second pipe 2012 to be heated and output again from the first port of the heat pump superheating section heat exchanger 101, thereby forming a cycle.

[0051] In this embodiment, the second and third three-way valves of each heat storage module can be adjusted to control the flow direction of the liquid in the high-temperature hot water circuit 201, thereby performing sensible heat storage in each heat storage module. Specifically, for the first heat storage module 301, the second three-way valve 3012 and the third three-way valve 3013 of the first heat storage module are adjusted to connect the first heat storage module 301 with the heat exchanger 101 of the superheating section of the heat pump via the high-temperature hot water circuit 201. At this point, the high-temperature hot water output by the heat exchanger 101 of the superheating section of the heat pump can be used to perform sensible heat storage in the first heat storage module 301. The same applies to the second heat storage module 302 and the Xth heat storage module 30X. The second three-way valve 3022 and the third three-way valve 3023 of the second heat storage module are adjusted to connect the second heat storage module 302 to the heat pump superheating section heat exchanger 101 via the high-temperature hot water circuit 201. Sensible heat storage can now be performed in the second heat storage module 302 using the high-temperature hot water output from the heat pump superheating section heat exchanger 101. The second three-way valve 30X2 and the third three-way valve 30X3 of the Xth heat storage module are adjusted to connect the Xth heat storage module 30X to the heat pump superheating section heat exchanger 101 via the high-temperature hot water circuit 201. Sensible heat storage can now be performed in the Xth heat storage module 30X using the high-temperature hot water output from the heat pump superheating section heat exchanger 101.

[0052] In some embodiments, as Figure 1 As shown, the water vapor circuit 202 includes a third pipe 2021 and a fourth pipe 2022. One end of the third pipe 2021 is connected to the first port of the heat pump two-phase section heat exchanger 102, and the other end thereof is connected in sequence to the first three-way valve of each heat storage module and then to the water inlet end of the water vapor buffer tank 602. One end of the fourth pipe 2022 is connected to the water outlet end of the water vapor buffer tank 602, and the other end thereof is connected in sequence to the fourth three-way valve of each heat storage module and then to the second port of the heat pump two-phase section heat exchanger 102.

[0053] The first port of the heat pump two-phase heat exchanger 102 outputs water vapor, which is transmitted to the heat storage module through the third pipe 2021. After exchanging heat with the heat storage module, the water vapor loses heat and becomes condensed water, which is returned to the heat pump two-phase heat exchanger 102 through the fourth pipe 2022. The second water pump 402 can provide power for the reflux of condensed water.

[0054] In this embodiment, the flow direction of the medium (water vapor or condensed water) in the water vapor circuit 202 can be adjusted by adjusting the first and fourth three-way valves of each heat storage module to achieve latent heat storage in each heat storage module. Specifically, for the first heat storage module 301, the first three-way valve 3011 and the fourth three-way valve 3014 of the first heat storage module are adjusted to connect the first heat storage module 301 with the heat pump two-phase heat exchanger 102 through the water vapor circuit 202. At this time, the water vapor output from the water vapor circuit 202 can be used to store latent heat in the first heat storage module 301. The same applies to the second heat storage module 302 and the Xth heat storage module 30X. The first three-way valve 3021 and the fourth three-way valve 3024 of the second heat storage module are adjusted to connect the second heat storage module 302 to the heat pump two-phase heat exchanger 102 via the water vapor circuit 202. At this point, latent heat storage can be performed in the second heat storage module 302 using the water vapor output from the water vapor circuit 202. The first three-way valve 30X1 and the fourth three-way valve 30X4 of the Xth heat storage module are adjusted to connect the Xth heat storage module 30X to the heat pump two-phase heat exchanger 102 via the water vapor circuit 202. At this point, latent heat storage can be performed in the Xth heat storage module 30X using the water vapor output from the water vapor circuit 202.

[0055] In some embodiments, each thermal storage module is equipped with a molten salt thermal storage medium, typically a nitrate, such as sodium nitrate, potassium nitrate, sodium nitrite, and mixtures thereof, or a chloride salt or carbonate salt. Different salts are selected based on the thermal storage temperature. Since water vapor and high-temperature hot water are stored here, a low-melting-point nitrate mixture is selected, with a melting point range of 100-200°C.

[0056] In some embodiments, as Figure 1 As shown, the high-temperature hot water circuit 201 and the water steam circuit 202 are further connected to a high-temperature hot water interface 701 and a water steam interface 702 respectively. The high-temperature hot water interface 701 and the water steam interface 702 can be used to meet the daily use needs of high-temperature hot water and water steam in industry.

[0057] In some embodiments, a heat storage system for simultaneously storing sensible heat and latent heat from phase change in a heat pump further includes a controller, which is signal-connected to the first water pump 401, the second water pump 402, and a plurality of three-way valves (e.g., 3011, 3012, 3013, 3014, 3021, 3022, 3023, 3024, 30X1, 30X2, 30X3, and 30X4) provided on the heat storage module. A computer program can be configured in the controller to control the operation of the first water pump 401, the second water pump 402, and the plurality of three-way valves provided on the heat storage module based on a set program, thereby achieving automated simultaneous storage of sensible heat and latent heat from the high-temperature heat pump.

[0058] Example 2:

[0059] The present application provides an operating method of a heat storage system for synchronously storing sensible heat and latent heat of a heat pump as described in Example 1. The operating method can be implemented by controlling the corresponding electronic components connected to the controller 8 in the system, such as Figure 2 As shown, the operation method includes the following steps:

[0060] S10: Adjust all three-way valves provided on each heat storage module to an initial state. In the initial state, the high-temperature hot water circuit and the water vapor circuit are not connected to each heat storage module, and the heat pump superheating section heat exchanger and the heat pump two-phase section heat exchanger are connected to the high-temperature hot water buffer tank and the water vapor buffer tank through the high-temperature hot water circuit and the water vapor circuit, respectively.

[0061] Step S10 determines an initial state, in which the molten salt in each heat storage module is in solid state, and the switch states of all three-way valves are: the high-temperature hot water circuit and the water vapor circuit are not connected to each heat storage module, and the two circuits are only connected to their respective storage tanks.

[0062] S20: Regulate the three-way valve of the first heat storage module so that the first heat storage module is connected to the heat pump two-phase heat exchanger through the water vapor loop, and use the water vapor generated by the heat pump two-phase heat exchanger to store latent heat in the first heat storage module.

[0063] Taking the first heat storage module 301 as an example, the first valve three-way valve 3011 and the fourth valve three-way valve 3014 of the first heat storage module are opened to connect the water vapor circuit and the heat storage module 301. When the water vapor circuit 202 is connected to the first heat storage module 301, the water vapor does not pass through the subsequent circuit and is not connected to the water vapor buffer tank 602. At this time, the molten salt in the first heat storage module 301 begins to melt and store latent heat, and the water vapor releases latent heat and condenses into saturated liquid water. After the molten salt in the first heat storage module 301 is completely melted, the first valve three-way valve 3011 and the fourth valve three-way valve 3014 of the first heat storage module are turned to close the water vapor circuit and the first heat storage module 301. At this time, the first heat storage module 301 completes latent heat storage.

[0064] In some embodiments, the method for determining whether the molten salt in the first heat storage module 301 is completely melted can be: by configuring a temperature sensor in the heat storage module 301, sending a temperature signal to the controller according to the temperature sensor, and when the preset temperature is reached, it can be determined that the molten salt in the first heat storage module 301 is completely melted, and subsequent valve control operations can be performed at this time.

[0065] S30: After the first heat storage module completes latent heat storage, the three-way valve of the first heat storage module is adjusted so that the first heat storage module is connected to the heat exchanger of the superheating section of the heat pump through the high-temperature hot water circuit, and the high-temperature hot water generated by the heat exchanger of the superheating section of the heat pump is used to perform sensible heat storage in the first heat storage module until the heat storage temperature of the heat storage module reaches the target temperature, and the three-way valve of the first heat storage module is reset. After the first heat storage module completes latent heat storage, the three-way valve of the first heat storage module is adjusted, and at the same time, the three-way valve of the second heat storage module is adjusted so that the second heat storage module is connected to the two-phase heat exchanger of the heat pump through the water vapor circuit, and the water vapor generated by the two-phase heat exchanger of the heat pump is used to perform latent heat storage in the second heat storage module.

[0066] It should be noted that the target temperature is the set heat storage temperature and can be reasonably set according to the actual application scenario. This embodiment does not specifically limit the target temperature value. The target temperature is generally not higher than the maximum temperature of high-temperature hot water. The high-temperature hot water described in this article refers to high-temperature hot water in the fields of industrial production and thermal engineering, with a temperature range of 150-250°C and maintained in a liquid state at a pressure of 0.4-3.0 MPa.

[0067] Resetting the three-way valve of the first heat storage module refers to adjusting the three-way valve so that the first heat storage module is neither connected to the high-temperature hot water circuit nor to the water vapor circuit.

[0068] like Figure 3 FIG. 1 is a partial flow chart of a method for operating a heat storage system for synchronously storing heat pump sensible heat and phase change latent heat provided in an embodiment of the present application. Step S30 can be implemented by the following steps:

[0069] S310: Determine that latent heat storage in the first heat storage module is completed, and execute S320 and S330 simultaneously.

[0070] S320: Perform sensible heat storage on the first heat storage module.

[0071] S330: Perform latent heat storage in the second heat storage module.

[0072] Among them, the method of performing sensible heat storage on the first heat storage module in step S320 is to adjust the three-way valve of the first heat storage module so that the first heat storage module is connected to the heat exchanger of the superheating section of the heat pump through the high-temperature hot water circuit, and use the high-temperature hot water generated by the heat exchanger of the superheating section of the heat pump to perform sensible heat storage on the first heat storage module until the heat storage temperature of the heat storage module reaches the target temperature, and then reset the three-way valve of the first heat storage module.

[0073] In step S330, the method of performing latent heat storage in the second heat storage module is to adjust the three-way valve of the second heat storage module so that the second heat storage module is connected to the heat pump two-phase heat exchanger through the water vapor circuit, and the water vapor generated by the heat pump two-phase heat exchanger is used to perform latent heat storage in the second heat storage module.

[0074] Step S30 includes two operations that are run simultaneously, that is, the second heat storage module 302 performs latent heat storage while the first heat storage module 301 performs sensible heat storage. Figure 1 As shown, the control method for latent heat storage in the second heat storage module 302 is consistent with the control method of the first heat storage module 301, that is, the first valve three-way valve 3021 and the fourth valve three-way valve 3024 of the first heat storage module are opened to connect the water vapor circuit with the second heat storage module 302. When the water vapor circuit 202 is connected to the second heat storage module 302, the water vapor does not pass through the subsequent circuit and is not connected to the water vapor buffer tank 602. At this time, the molten salt in the second heat storage module 302 begins to melt and store latent heat, and the water vapor releases latent heat and condenses into saturated liquid water. After the molten salt in the second heat storage module 302 is completely melted, the second valve three-way valve 3021 and the fourth valve three-way valve 3024 of the second heat storage module are rotated to close the water vapor circuit and the second heat storage module 302. At this time, the first heat storage module 302 completes latent heat storage.

[0075] When the first heat storage module 301 is performing sensible heat storage, the second three-way valve 3012 and the third three-way valve 3013 of the first heat storage module are opened to connect the high-temperature hot water circuit 201 with the first heat storage module 301, and the sensible heat storage of the first heat storage module 301 is started. It should be noted that at this time, the sensible heat storage of the first heat storage module 301 and the latent heat storage of the second heat storage module 302 are carried out synchronously. When the high-temperature hot water passing through the second three-way valve 3012 and the third three-way valve 3013 of the first heat storage module is connected to the first heat storage module 301, the high-temperature hot water circuit 201 is connected to the first heat storage module 301. The water does not pass through the subsequent circuit. After the high-temperature hot water passes through the first heat storage module 301, the temperature of the melted salt in the first heat storage module 301 begins to rise, and the temperature of the hot water begins to decrease. When the temperature of the molten salt in the first heat storage module 301 is fully increased to the maximum temperature of the high-temperature hot water, the first heat storage module 301 completes heat storage. The second three-way valve 3012 and the third three-way valve 3013 of the first heat storage module are adjusted to disconnect the high-temperature hot water circuit 201 from the first heat storage module 301, thereby completing the sensible heat and latent heat storage of the first heat storage module 301.

[0076] S40: Control each heat storage module in sequence according to the above steps in a loop until all heat storage modules have completed heat storage.

[0077] According to the above process, several heat storage modules are arranged in a certain order, and the sensible heat of the current module and the latent heat of the next module are stored simultaneously. The purpose of this design is to solve the problem of the heat pump producing water vapor and high-temperature hot water at the same time.

[0078] The above implementation modes are only used to illustrate the present application and are not intended to limit the present application. Ordinary technicians in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present application. Therefore, all equivalent technical solutions also fall within the scope of the present application, and the scope of patent protection of the present application shall be defined by the claims.

Claims

1. A heat storage system for synchronously storing heat pump sensible heat and phase change latent heat, characterized in that: include: The heat exchanger in the superheating section of the heat pump corresponds to the heat release circuit of the organic working fluid of the heat pump and is used to produce high-temperature hot water; The heat pump two-phase heat exchanger is set corresponding to the heat pump's organic working fluid heat release circuit and is used to produce water vapor; A high-temperature hot water circuit, wherein a first water pump is provided on the high-temperature hot water circuit; a water vapor circuit, wherein a second water pump is provided on the water vapor circuit; The heat storage device includes a plurality of heat storage modules, each of which is provided with a plurality of three-way valves. The heat pump superheating section heat exchanger is connected to the three-way valve of each heat storage module through the high-temperature hot water circuit, and the heat pump two-phase section heat exchanger is connected to the three-way valve of each heat storage module through the water vapor circuit; High-temperature hot water buffer tank, the heat pump superheating section heat exchanger is connected to the high-temperature hot water buffer tank through the high-temperature hot water circuit, A water vapor buffer tank, wherein the heat pump two-phase heat exchanger is connected to the water vapor buffer tank through the water vapor loop.

2. The heat storage system for synchronously storing sensible heat and latent heat of a heat pump according to claim 1, characterized in that: The heat storage module is provided with four three-way valves, namely a first three-way valve, a second three-way valve, a third three-way valve and a fourth three-way valve.

3. The heat storage system for synchronously storing sensible heat and latent heat of a heat pump according to claim 2, characterized in that: The high-temperature hot water circuit includes a first pipe and a second pipe, one end of the first pipe is connected to the first port of the heat pump superheating section heat exchanger, and the other end thereof is connected in sequence to the second three-way valve of each of the heat storage modules and then to the water inlet end of the high-temperature hot water buffer tank; one end of the second pipe is connected to the water outlet end of the high-temperature hot water buffer tank, and the other end thereof is connected in sequence to the third three-way valve of each of the heat storage modules and then to the second port of the heat pump superheating section heat exchanger.

4. The heat storage system for synchronously storing sensible heat and latent heat of a heat pump according to claim 2, characterized in that: The water vapor circuit includes a third pipe and a fourth pipe, one end of the third pipe is connected to the first port of the heat pump two-phase section heat exchanger, and the other end thereof is connected in sequence to the first three-way valve of each of the heat storage modules and then to the water inlet end of the water vapor buffer tank; one end of the fourth pipe is connected to the water outlet end of the water vapor buffer tank, and the other end thereof is connected in sequence to the fourth three-way valve of each of the heat storage modules and then to the second port of the heat pump two-phase section heat exchanger.

5. The heat storage system for synchronously storing heat pump sensible heat and phase change latent heat according to claim 1, characterized in that: Each of the heat storage modules is provided with a molten salt heat storage medium, wherein the molten salt heat storage medium is nitrate, chloride or carbonate, and the nitrate is sodium nitrate, potassium nitrate, sodium nitrite and a mixture thereof.

6. The heat storage system for simultaneously storing sensible heat and latent heat of a heat pump according to any one of claims 1 to 5, characterized in that: It also includes a controller, which is signal-connected to the first water pump, the second water pump, and a plurality of three-way valves provided on the heat storage module.

7. A method for operating a heat storage system for simultaneously storing sensible heat and latent heat of a heat pump according to any one of claims 1 to 6, characterized in that: The operation method includes: Adjusting all three-way valves provided on each heat storage module to an initial state, in which the high-temperature hot water circuit and the water vapor circuit are disconnected from each heat storage module, and the heat pump superheating section heat exchanger and the heat pump two-phase section heat exchanger are connected to the high-temperature hot water buffer tank and the water vapor buffer tank respectively through the high-temperature hot water circuit and the water vapor circuit; Adjusting the three-way valve of the first heat storage module so that the first heat storage module is connected to the heat pump two-phase heat exchanger through the water vapor circuit, and utilizing the water vapor generated by the heat pump two-phase heat exchanger to perform latent heat storage in the first heat storage module; After the first heat storage module completes latent heat storage, the three-way valve of the first heat storage module is adjusted so that the first heat storage module is connected to the heat pump superheating section heat exchanger through the high-temperature hot water circuit, and the high-temperature hot water generated by the heat pump superheating section heat exchanger is used to perform sensible heat storage in the first heat storage module until the heat storage temperature of the heat storage module reaches the target temperature, and the three-way valve of the first heat storage module is reset. After the first heat storage module completes latent heat storage, the three-way valve of the first heat storage module is adjusted, and at the same time, the three-way valve of the second heat storage module is adjusted so that the second heat storage module is connected to the heat pump two-phase section heat exchanger through the water vapor circuit, and the water vapor generated by the heat pump two-phase section heat exchanger is used to perform latent heat storage in the second heat storage module; According to the above steps, each heat storage module is controlled in sequence in a cycle until all heat storage modules have completed heat storage.

8. The operating method according to claim 7, characterized in that: If the heat storage medium in the first heat storage module is completely dissolved, it is determined that the latent heat storage of the first heat storage module is completed.

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