A distributed single-tank heat storage power generation system and an operating method thereof

Abstract

The application discloses a kind of distributed single-tank heat storage power generation systems and operating methods, including double-temperature stage power generation system;Double-temperature stage power generation system includes heat storage tank, mixed desuperheater, ejector, high-temperature turbine generator, low-temperature turbine generator, high-temperature regenerator, main compressor, cooler, low-temperature regenerator, re-compressor;Wherein, heat storage tank further includes the tank body with heat storage material, first spiral tube bundle, second spiral tube bundle and electric heater;Electric heating is vertically arranged in heat storage tank, and first spiral tube bundle and second spiral tube bundle are vertically symmetrically arranged on the two sides of electric heater.The application realizes that high and low temperature turbine generator import temperature always remains constant when heat storage tank releases heat by high and low temperature stage working medium outlet cooperation cooling device, effectively solves the variable working condition problem caused by sliding temperature operation when single-tank heat storage tank drives power generation system, improves the stability of power generation system and the utilization efficiency of energy in system.

Description

Technical Field

[0001] This invention relates to the field of thermal energy storage technology, specifically to a distributed single-tank thermal energy storage power generation system and its operation method. Background Technology

[0002] Currently, most mainstream thermal energy storage power generation systems use molten salt as the thermal storage medium. Molten salt thermal energy storage power generation systems generally adopt the relatively mature dual-tank molten salt thermal energy storage system, which uses two large molten salt tanks to store high-temperature molten salt and low-temperature molten salt. At the same time, an external molten salt heat exchanger is used for heat storage and release. However, dual-tank molten salt thermal energy storage systems have obvious drawbacks such as large footprint, high construction and maintenance costs, and poor economic efficiency. Therefore, more and more scholars are turning their research focus to single-tank molten salt thermal energy storage systems.

[0003] Existing single-tank molten salt thermal energy storage systems typically employ thermocentric molten salt thermal energy storage technology. While this reduces fixed investment compared to dual-tank molten salt thermal energy storage systems, research has revealed that temperature stratification within a single thermocentric molten salt tank is difficult to maintain stably, resulting in uneven temperature distribution within the tank and affecting heat exchange efficiency and the stability of the heat transfer medium's outlet temperature. Furthermore, if non-thermocentric molten salt thermal energy storage technology is used, molten salt still needs to be transported to external pipelines and heat exchange equipment via molten salt pumps. As the heat release process proceeds, the temperature inside the molten salt tank decreases, causing a drop in the temperature of the heated working fluid in the power generation system. This leads to changes in the turbine's inlet temperature, resulting in off-design operating conditions and decreased efficiency of the rotating machinery and the power generation system. In other words, the power generation system operates in a temperature-slip condition, severely impacting the system's energy utilization and power generation efficiency.

[0004] Based on this, the present invention provides a distributed single-tank thermal energy storage power generation system and its operation method, which solves the problem of variable operating conditions caused by temperature sliding operation when using a single-tank molten salt thermal energy storage power generation system. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention provides a distributed single-tank thermal energy storage power generation system and its operation method, which solves the problem of variable operating conditions caused by temperature sliding operation during power generation in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] In a first aspect, a distributed single-tank thermal energy storage power generation system is provided, including a dual-temperature stage power generation system; the dual-temperature stage power generation system includes a thermal energy storage tank, a mixing desuperheater, an ejector, a high-temperature turbine generator, a low-temperature turbine generator, a high-temperature regenerator, a main compressor, and a cooler.

[0008] The thermal storage tank includes a working fluid outlet and a working fluid inlet. The working fluid outlet of the thermal storage tank is connected to the high-temperature working fluid inlet of the mixing desuperheater and the ejector working fluid inlet of the ejector, respectively. The cooling working fluid outlet of the mixing desuperheater is connected to the working fluid inlet of the high-temperature turbine generator. The mixing working fluid outlet of the ejector is connected to the working fluid inlet of the low-temperature turbine generator.

[0009] The working fluid outlets of the high-temperature turbine generator and the low-temperature turbine generator are both connected to the hot fluid inlet of the high-temperature regenerator. The cooler and the main compressor are connected in sequence between the hot fluid outlet and the cold fluid inlet of the high-temperature regenerator. The cold fluid outlet of the high-temperature regenerator is connected to the working fluid inlet of the heat storage tank.

[0010] Furthermore, the dual-temperature power generation system also includes a low-temperature regenerator and a recompressor; the hot fluid outlet of the high-temperature regenerator is connected to the hot fluid inlet of the low-temperature regenerator, and the hot fluid outlet of the low-temperature regenerator is divided into two paths: one path is connected to the inlet of the cooler, the outlet of the cooler is connected to the inlet of the main compressor, the outlet of the main compressor is connected to the cold fluid inlet of the low-temperature regenerator, and the cold fluid outlet of the low-temperature regenerator is connected to the cold fluid inlet of the high-temperature regenerator; the other path is connected to the inlet of the recompressor, and the outlet of the recompressor is connected to the cold fluid inlet of the high-temperature regenerator; the cold fluid outlet of the high-temperature regenerator is connected to the working fluid inlet of the thermal storage tank.

[0011] Furthermore, the cold fluid outlet of the cryogenic regenerator and the outlet of the recompressor are both connected to the cryogenic working fluid inlet of the mixing desuperheater; the hot fluid outlet of the cryogenic regenerator is connected to the ejected working fluid inlet of the ejector.

[0012] Furthermore, the heat storage tank also includes a tank body containing heat storage material, a first spiral tube bundle, a second spiral tube bundle, and an electric heater; the electric heater is vertically arranged inside the heat storage tank, and the first and second spiral tube bundles are vertically symmetrically arranged on both sides of the electric heater.

[0013] Furthermore, one end of the first helical tube bundle is provided with a first working fluid inlet side, and the other end is provided with a first working fluid outlet side; one end of the second helical tube bundle is provided with a second working fluid inlet side, and the other end is provided with a second working fluid outlet side.

[0014] The first working fluid inlet side and the first working fluid outlet side of the first solenoid bundle are arranged opposite to the second working fluid inlet side and the second working fluid outlet side of the second solenoid bundle, so that the working fluid in the first solenoid bundle and the second solenoid bundle flows in opposite directions in the vertical direction.

[0015] Both the first working fluid inlet side and the second working fluid inlet side are connected to the cold fluid outlet of the high-temperature regenerator; both the first working fluid outlet side and the second working fluid outlet side are connected to the high-temperature working fluid inlet of the mixing desuperheater and the ejector working fluid inlet of the ejector.

[0016] Furthermore, it also includes a valve assembly, which includes a first valve, a second valve, a third valve, and a fourth valve; the first valve is installed on the high-temperature working fluid inlet pipe of the mixing desuperheater, the second valve is installed on the ejector working fluid inlet pipe of the ejector, the third valve is installed on the pipe connecting the low-temperature working fluid inlet of the mixing desuperheater and the cold fluid outlet of the low-temperature regenerator, and the fourth valve is installed on the pipe connecting the ejected working fluid inlet of the ejector and the hot fluid outlet of the low-temperature regenerator.

[0017] Secondly, a method for operating a distributed single-tank thermal energy storage power generation system is provided, including thermal energy storage mode, high-temperature working fluid power generation mode and low-temperature working fluid power generation mode, and switching between the three modes is achieved by opening and closing valves in the valve group according to the temperature of the thermal energy storage material in the thermal energy storage tank.

[0018] The heat storage temperature zone of the heat storage tank is T. min —T max The temperature of the heat storage material inside the heat storage tank is T. tank The inlet temperature of the high-temperature turbine generator is T. H The inlet temperature of the cryogenic turbine generator is T. L Among them, T max >T H >T min ≥T L ;

[0019] When T tank <T min At this time, all valves are closed, and the power generation system switches to the aforementioned thermal storage mode;

[0020] When T tank >T H At this time, the first and third valves are opened, and the second and fourth valves are closed, and the power generation system switches to the high-temperature working fluid power generation mode.

[0021] When T tank ≤T H At this time, open the second and fourth valves, close the first and third valves, and the power generation system switches to cryogenic working fluid power generation mode;

[0022] When T tank =T min At that time, the cryogenic working fluid power generation mode is turned off.

[0023] Furthermore, when switching to thermal storage mode, the electric heater is turned on to heat the thermal storage material, and the thermal storage material is heated to T. max Then turn off the heat storage mode.

[0024] Furthermore, when switching to the high-temperature working fluid power generation mode, the working fluid at the outlet of the high-temperature working fluid tank enters the mixing desuperheater to be cooled to T. H Afterward, the working fluid enters the high-temperature turbine generator to expand and do work, generating electricity. The working fluid from the outlet of the high-temperature turbine generator enters the high-temperature regenerator and the low-temperature regenerator in sequence to release heat. After releasing heat, part of the working fluid enters the re-compressor to increase pressure, and the other part enters the cooler to cool before entering the main compressor to increase pressure. The working fluid from the outlet of the main compressor first enters the low-temperature regenerator to absorb heat and increase temperature, and then merges with the working fluid from the outlet of the re-compressor. Together, they enter the high-temperature regenerator and the heat storage tank to be heated, completing the high-temperature working fluid power generation cycle.

[0025] Furthermore, when switching to cryogenic working fluid power generation mode, the working fluid from the cryogenic working fluid outlet of the thermal storage tank enters the ejector and is cooled to T. L Afterward, the working fluid enters the cryogenic turbine generator to expand and do work, generating electricity. The working fluid at the outlet of the cryogenic turbine generator enters the high-temperature regenerator and the cryogenic regenerator in sequence to release heat. After releasing heat, part of the working fluid enters the recompressor to increase its pressure, and the other part enters the cooler to cool and then enters the main compressor to increase its pressure. The working fluid at the outlet of the main compressor first enters the cryogenic regenerator to absorb heat and increase its temperature, and then merges with the working fluid at the outlet of the recompressor. Together, they enter the high-temperature regenerator and the heat storage tank to be heated, completing the cryogenic stage working fluid power generation cycle.

[0026] The beneficial effects of the embodiments provided by the present invention include:

[0027] This invention provides a distributed single-tank thermal energy storage power generation system and its operation method. By using a cooling device in conjunction with the outlet of the high and low temperature working fluid, the inlet temperature of the high and low temperature turbine generator is kept constant when the thermal energy storage tank releases heat. This effectively solves the problem of variable operating conditions caused by temperature sliding operation when the single-tank thermal energy storage tank drives the power generation system, and improves the stability of the power generation system and the energy utilization efficiency of the system. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the system structure provided in an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of the integrated system structure provided in the embodiments of the present invention.

[0030] Figure 3 This is a schematic diagram of a high-temperature power generation system provided in an embodiment of the present invention;

[0031] Figure 4A schematic diagram of a cryogenic power generation system provided in an embodiment of the present invention.

[0032] Wherein: 1 is the heat storage tank, 2 is the first spiral tube bundle, 21 is the first working fluid inlet side, 22 is the first working fluid outlet side, 3 is the second spiral tube bundle, 31 is the second working fluid outlet side, 32 is the second working fluid inlet side, 4 is the electric heater, 5 is the mixing desuperheater, 6 is the high-temperature turbine generator, 7 is the ejector, 8 is the low-temperature turbine generator, 9 is the recompressor, 10 is the main compressor, 11 is the high-temperature regenerator, 12 is the low-temperature regenerator, 13 is the cooler, 141 is the first valve, 142 is the second valve, 143 is the third valve, and 144 is the fourth valve. Detailed Implementation

[0033] The features and exemplary embodiments of various aspects of the present invention will now be described in detail. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention.

[0034] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] Example 1

[0038] like Figure 1As shown, this embodiment provides a distributed single-tank thermal energy storage power generation system, including a dual-temperature stage power generation system;

[0039] In some embodiments, a dual-temperature stage power generation system is included; the dual-temperature stage power generation system includes a thermal storage tank 1, a mixing desuperheater 5, a high-temperature turbine generator 6, an ejector 7, a low-temperature turbine generator 8, a main compressor 10, a high-temperature regenerator 11, and a cooler 13; wherein, the thermal storage tank 1 includes a working fluid outlet and a working fluid inlet;

[0040] Specifically, the working fluid outlet of the heat storage tank 1 is connected to the high-temperature working fluid inlet of the mixing desuperheater 5, and the cooling working fluid outlet of the mixing desuperheater 5 is connected to the inlet of the high-temperature turbine generator 6, forming a high-temperature working fluid power generation system.

[0041] Specifically, the working fluid outlet of the thermal storage tank 1 is connected to the ejector working fluid inlet of the ejector 7, and the mixed working fluid outlet of the ejector 7 is connected to the inlet of the cryogenic turbine generator 8, forming a cryogenic working fluid power generation system.

[0042] Specifically, the hot fluid inlet of the high-temperature regenerator is connected to the outlet of the high-temperature turbine generator and the outlet of the low-temperature turbine generator, respectively. The hot fluid outlet of the high-temperature regenerator is connected to the inlet of the cooler. The outlet of the cooler is connected to the inlet of the main compressor. The outlet of the main compressor is connected to the cold fluid inlet of the high-temperature regenerator. The cold fluid outlet of the high-temperature regenerator is connected to the working fluid inlet of the heat storage tank, forming a working fluid heat release and pressurization system.

[0043] In some embodiments, the cooler 13 employs either water cooling or air cooling.

[0044] Example 2

[0045] This embodiment provides a distributed single-tank thermal energy storage power generation system, which differs from Embodiment 1 in that the dual-temperature stage power generation system also includes a low-temperature regenerator and a recompressor;

[0046] Specifically, the hot fluid outlet of the high-temperature regenerator 11 is connected to the hot fluid inlet of the low-temperature regenerator 12. The hot fluid outlet of the low-temperature regenerator 12 is divided into two paths: one path is connected to the inlet of the cooler 13, the outlet of the cooler 13 is connected to the inlet of the main compressor 10, the outlet of the main compressor 10 is connected to the cold fluid inlet of the low-temperature regenerator 12, and the cold fluid outlet of the low-temperature regenerator 12 is connected to the cold fluid inlet of the high-temperature regenerator 11; the other path is connected to the inlet of the recompressor 9, the outlet of the recompressor 9 is connected to the cold fluid inlet of the high-temperature regenerator 11; and the cold fluid outlet of the high-temperature regenerator 11 is connected to the working fluid inlet of the heat storage tank 1.

[0047] In some embodiments, the working fluid in a dual-temperature power generation system is supercritical carbon dioxide.

[0048] Example 3

[0049] This embodiment provides a distributed single-tank thermal energy storage power generation system, which differs from Embodiment 2 in that the cold fluid outlet of the low-temperature regenerator 12 and the outlet of the recompressor 9 are both connected to the low-temperature working fluid inlet of the mixing desuperheater 5; the hot fluid outlet of the low-temperature regenerator 12 is connected to the ejected working fluid inlet of the ejector 7.

[0050] In this embodiment, the low-temperature working fluid from the cold fluid outlet of the low-temperature regenerator 12 and the low-temperature working fluid from the outlet of the recompressor 9 are introduced into the mixing desuperheater 5 to cool the high-temperature working fluid from the outlet of the heat storage tank 1 in the mixing desuperheater 5; and the low-temperature working fluid from the hot fluid outlet of the low-temperature regenerator 12 is introduced into the ejector 7 to cool the low-temperature working fluid from the outlet of the heat storage tank 1 in the ejector 7.

[0051] Example 4

[0052] This embodiment provides a distributed single-tank thermal energy storage power generation system, which differs from Embodiment 3 in that the thermal energy storage tank 1 includes a tank body containing thermal energy storage material, a first spiral tube bundle 2, a second spiral tube bundle 3, and an electric heater 4; the electric heater is vertically arranged inside the thermal energy storage tank 1, and the first spiral tube bundle 2 and the second spiral tube bundle 3 are vertically symmetrically arranged on both sides of the electric heater 4.

[0053] Specifically, one end of the first spiral tube bundle 2 is provided with a first working medium inlet side 21, and the other end is provided with a first working medium outlet side 22; one end of the second spiral tube bundle 3 is provided with a second working medium inlet side 32, and the other end is provided with a second working medium outlet side 31.

[0054] The first working fluid inlet side 21 and the first working fluid outlet side 22 of the first solenoid bundle 2 are arranged opposite to the second working fluid inlet side 32 and the second working fluid outlet side 31 of the second solenoid bundle 3. By making the working fluid in the first solenoid bundle 2 and the second solenoid bundle 3 flow in opposite directions in the vertical direction, the temperature of the molten salt in the heat storage tank changes uniformly.

[0055] Specifically, the first working fluid inlet side 21 and the second working fluid inlet side 32 are both connected to the cold fluid outlet of the high-temperature regenerator; the first working fluid outlet side 22 and the second working fluid outlet side 32 are both connected to the high-temperature working fluid inlet of the mixing desuperheater and the ejector working fluid inlet of the ejector.

[0056] In some embodiments, the heat storage material may be either molten salt or heat transfer oil.

[0057] In this embodiment, the electric heater 4 and the heat exchange tube bundle are integrated into the heat storage tank 1 to achieve the functions of heat absorption, heat preservation and heat release in one unit. The electric heater 4 heats the heat storage material in the heat storage tank 1, and the heat transfer effect is used to heat the working fluid in the first spiral tube bundle 2 and the second spiral tube bundle 3.

[0058] Example 5

[0059] like Figure 2 As shown, this embodiment provides a distributed single-tank thermal energy storage power generation system. The difference between this system and embodiment 4 is that it also includes a valve group, which includes a first valve 141, a second valve 142, a third valve 143, and a fourth valve 144. The first valve 141 is installed on the high-temperature working fluid inlet pipe of the mixing desuperheater 5, the second valve 142 is installed on the ejector working fluid inlet pipe of the ejector 7, the third valve 143 is installed on the pipe connecting the low-temperature working fluid inlet of the mixing desuperheater 5 and the cold fluid outlet of the low-temperature regenerator 12, and the fourth valve 144 is installed on the pipe connecting the ejected working fluid inlet of the ejector 7 and the hot fluid outlet of the low-temperature regenerator 12.

[0060] In this embodiment, by controlling the valve group, the connecting pipelines between different devices can be connected into a loop or cut off to achieve the corresponding operating mode.

[0061] Example 6

[0062] Based on the distributed single-tank thermal power generation system provided in the above embodiments, this embodiment provides an operation method for the distributed single-tank thermal power generation system. The operation method includes thermal storage mode, high-temperature working fluid power generation mode and low-temperature working fluid power generation mode, and the switching between the three modes is achieved by opening and closing valves in the valve group according to the temperature of the thermal storage material in the thermal storage tank.

[0063] In some embodiments, the heat storage temperature zone of the heat storage tank 1 is T. min —T max The temperature of the heat storage material inside the heat storage tank 1 is T. tank The inlet temperature of the high-temperature turbine generator 6 is T. H The inlet temperature of the cryogenic turbine generator 8 is T. L Among them, T max >T H >T min ≥T L ;

[0064] Specifically, when T tank <T minWhen all valves are closed, the power generation system switches to the aforementioned thermal storage mode. The thermal storage material is heated by turning on the electric heater 4, and the working fluid in the first spiral tube bundle 2 and the second spiral tube bundle 3 is heated using the thermal storage material. When the thermal storage material reaches temperature T... max Then turn off the heat storage mode.

[0065] Specifically, such as Figure 3 As shown, when T tank >T H At this time, the first and third valves are opened, and the second and fourth valves are closed. The power generation system switches to the high-temperature working fluid power generation mode. The working fluid at the outlet of the high-temperature working fluid tank 1 enters the mixing desuperheater 5 to be cooled to the inlet temperature T of the high-temperature turbine generator 6. H Afterwards, the working fluid enters the high-temperature turbine generator 6 to expand and perform work, generating electricity. The working fluid from the outlet of the high-temperature turbine generator 6 sequentially enters the high-temperature regenerator 11 and the low-temperature regenerator 12 to release heat. Part of the released working fluid enters the recompressor 9 for pressurization, and the other part enters the cooler 13 for cooling before entering the main compressor 10 for pressurization. The working fluid from the outlet of the main compressor 10 first enters the low-temperature regenerator 12 to absorb heat and increase its temperature, and then merges with the working fluid from the outlet of the recompressor 9, entering the high-temperature regenerator 11 and the heat storage tank 1 together to be heated, completing the high-temperature stage working fluid power generation cycle. At the same time, part of the cooled working fluid is sent to the mixing desuperheater 5 through the third valve 143 to cool the high-temperature stage working fluid; as the discharge time increases, the temperature T of the heat storage material in the heat storage tank 1... tank As the temperature of the working fluid at the outlet of the thermal storage tank 1 decreases, the required low-temperature working fluid for the mixing desuperheater 5 also decreases. Therefore, the opening of the third valve should be reduced to maintain the inlet working fluid temperature T of the high-temperature turbine generator 6. H constant.

[0066] Specifically, such as Figure 4 As shown, when T tank ≤T H At this time, the second and fourth valves are opened, and the first and third valves are closed. The power generation system switches to cryogenic working fluid power generation mode. The working fluid at the outlet of the cryogenic working fluid tank 1 enters the ejector 7 and is cooled to the inlet temperature T of the cryogenic turbine generator 8. LAfterwards, the working fluid enters the cryogenic turbine generator 8 to expand and perform work, generating electricity. The working fluid from the outlet of the cryogenic turbine generator 8 sequentially enters the high-temperature regenerator 11 and the cryogenic regenerator 12 to release heat. Part of the released working fluid enters the recompressor 9 for pressurization, and the other part enters the cooler 13 for cooling before entering the main compressor 10 for pressurization. The working fluid from the outlet of the main compressor 10 first enters the cryogenic regenerator 12 to absorb heat and increase its temperature, and then merges with the working fluid from the outlet of the recompressor 9, entering the high-temperature regenerator 11 and the heat storage tank 1 together to be heated, completing the cryogenic stage working fluid power generation cycle. At the same time, part of the cooled working fluid is sent to the ejector 7 through the fourth valve 144 to cool the cryogenic stage working fluid; as the discharge time increases, the temperature T of the heat storage material in the heat storage tank 1 increases. tank As the temperature continues to decrease, the outlet working fluid temperature of thermal storage tank 1 also decreases, reducing the amount of cryogenic working fluid required by ejector 7. At this point, the opening of the fourth valve should be reduced to maintain the inlet working fluid temperature T of the cryogenic turbine generator 8. L constant.

[0067] Specifically, when T tank =T min At that time, the cryogenic working fluid power generation mode is turned off.

[0068] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0069] The distributed single-tank thermal energy storage power generation system and operation method provided in the above embodiments have the following advantages compared with existing thermal energy storage power generation systems:

[0070] 1. This invention employs a dual-temperature-stage power generation system in conjunction with a de-cooling device to ensure that the inlet temperature of the high- and low-temperature turbine generator remains constant during heat release from the thermal storage tank. This effectively solves the problem of variable operating conditions caused by temperature sliding operation when a single-tank thermal storage tank drives a power generation system, thereby improving system stability.

[0071] 2. This invention integrates an electric heater and a heat exchange tube bundle into a heat storage tank, realizing a single-tank heat storage system that integrates the heat absorption, heat preservation, and heat release functions of the heat storage material. This simplifies the layout of traditional power generation systems, reduces the footprint of power generation systems, and improves the energy storage density and economy of power generation systems.

[0072] 3. This invention improves the energy utilization efficiency of the power generation system by introducing the cooled working fluid after heat release from the outlet of the low-temperature regenerator and / or the recompressor into the cooling device, thereby increasing the temperature of the working fluid entering the heat storage tank or reducing cooling losses.

[0073] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A distributed single-tank thermal energy storage power generation system, characterized in that, It includes a dual-temperature stage power generation system; the dual-temperature stage power generation system includes a thermal storage tank, a mixing desuperheater, an ejector, a high-temperature turbine generator, a low-temperature turbine generator, a high-temperature regenerator, a main compressor, and a cooler; The thermal storage tank includes a working fluid outlet and a working fluid inlet. The working fluid outlet of the thermal storage tank is connected to the high-temperature working fluid inlet of the mixing desuperheater and the ejector working fluid inlet of the ejector, respectively. The cooling working fluid outlet of the mixing desuperheater is connected to the working fluid inlet of the high-temperature turbine generator. The mixing working fluid outlet of the ejector is connected to the working fluid inlet of the low-temperature turbine generator. The working fluid outlets of the high-temperature turbine generator and the low-temperature turbine generator are both connected to the hot fluid inlet of the high-temperature regenerator. The cooler and the main compressor are connected in sequence between the hot fluid outlet and the cold fluid inlet of the high-temperature regenerator. The cold fluid outlet of the high-temperature regenerator is connected to the working fluid inlet of the heat storage tank.

2. The system according to claim 1, characterized in that, The dual-temperature power generation system also includes a low-temperature regenerator and a recompressor; The hot fluid outlet of the high-temperature regenerator is connected to the hot fluid inlet of the low-temperature regenerator. The hot fluid outlet of the low-temperature regenerator is divided into two paths: one path is connected to the inlet of the cooler, the outlet of the cooler is connected to the inlet of the main compressor, the outlet of the main compressor is connected to the cold fluid inlet of the low-temperature regenerator, and the cold fluid outlet of the low-temperature regenerator is connected to the cold fluid inlet of the high-temperature regenerator; the other path is connected to the inlet of the recompressor, and the outlet of the recompressor is connected to the cold fluid inlet of the high-temperature regenerator. The cold fluid outlet of the high-temperature regenerator is connected to the working fluid inlet of the heat storage tank.

3. The system according to claim 2, characterized in that, The cold fluid outlet of the cryogenic regenerator and the outlet of the recompressor are both connected to the cryogenic working fluid inlet of the mixing desuperheater; the hot fluid outlet of the cryogenic regenerator is connected to the ejected working fluid inlet of the ejector.

4. The system according to claim 1, characterized in that, The heat storage tank also includes a tank body containing heat storage material, a first spiral tube bundle, a second spiral tube bundle, and an electric heater; the electric heater is vertically arranged inside the heat storage tank, and the first and second spiral tube bundles are vertically symmetrically arranged on both sides of the electric heater.

5. The system according to claim 4, characterized in that, The first helical tube bundle has a first working fluid inlet side at one end and a first working fluid outlet side at the other end; the second helical tube bundle has a second working fluid inlet side at one end and a second working fluid outlet side at the other end. The first working fluid inlet side and the first working fluid outlet side of the first helical tube bundle are arranged opposite to the second working fluid inlet side and the second working fluid outlet side of the second helical tube bundle, so that the working fluid in the first helical tube bundle and the second helical tube bundle flows in opposite directions in the vertical direction. Both the first working fluid inlet side and the second working fluid inlet side are connected to the cold fluid outlet of the high-temperature regenerator; both the first working fluid outlet side and the second working fluid outlet side are connected to the high-temperature working fluid inlet of the mixing desuperheater and the ejector working fluid inlet of the ejector.

6. The system according to claim 2, characterized in that, It also includes a valve assembly, which includes a first valve, a second valve, a third valve, and a fourth valve; the first valve is installed on the high-temperature working fluid inlet pipe of the mixing desuperheater, the second valve is installed on the ejector working fluid inlet pipe of the ejector, the third valve is installed on the pipe connecting the low-temperature working fluid inlet of the mixing desuperheater and the cold fluid outlet of the low-temperature regenerator, and the fourth valve is installed on the pipe connecting the ejected working fluid inlet of the ejector and the hot fluid outlet of the low-temperature regenerator.

7. An operation method for a distributed single-tank thermal energy storage power generation system as described in claim 6, characterized in that, It includes thermal storage mode, high-temperature working fluid power generation mode and low-temperature working fluid power generation mode, and switches between the three modes by opening and closing valves in the valve group according to the temperature of the thermal storage material in the thermal storage tank. The heat storage temperature zone of the heat storage tank is T min— T max , the temperature of the heat storage material in the heat storage tank is T tank , the inlet temperature of the high-temperature turbine generator is T H , and the inlet temperature of the low-temperature turbine generator is T L ; wherein, T max >T H >T min ≥T L ; When T tank <T min At this time, all valves are closed, and the power generation system switches to the aforementioned thermal storage mode; When T tank >T H At this time, the first and third valves are opened, and the second and fourth valves are closed, and the power generation system switches to the high-temperature working fluid power generation mode. When T tank ≤T H At this time, open the second and fourth valves, close the first and third valves, and the power generation system switches to cryogenic working fluid power generation mode; When T tank =T min At that time, the cryogenic working fluid power generation mode is turned off.

8. The operating method according to claim 7, characterized in that, When switching to thermal storage mode, the electric heater is turned on to heat the thermal storage material, and the material is heated to T. max Then turn off the heat storage mode.

9. The operating method according to claim 7, characterized in that, When switching to high-temperature working fluid power generation mode, the working fluid at the outlet of the high-temperature working fluid tank enters the mixing desuperheater to be cooled to T. H Afterward, the working fluid enters the high-temperature turbine generator to expand and do work, generating electricity. The working fluid from the outlet of the high-temperature turbine generator enters the high-temperature regenerator and the low-temperature regenerator in sequence to release heat. After releasing heat, part of the working fluid enters the re-compressor to increase pressure, and the other part enters the cooler to cool before entering the main compressor to increase pressure. The working fluid from the outlet of the main compressor first enters the low-temperature regenerator to absorb heat and increase temperature, and then merges with the working fluid from the outlet of the re-compressor. Together, they enter the high-temperature regenerator and the heat storage tank to be heated, completing the high-temperature working fluid power generation cycle.

10. The operating method according to claim 7, characterized in that, When switching to cryogenic working fluid power generation mode, the working fluid at the cryogenic working fluid outlet of the thermal storage tank enters the ejector and is cooled to T. L Afterward, the working fluid enters the cryogenic turbine generator to expand and do work, generating electricity. The working fluid at the outlet of the cryogenic turbine generator enters the high-temperature regenerator and the cryogenic regenerator in sequence to release heat. After releasing heat, part of the working fluid enters the recompressor to increase its pressure, and the other part enters the cooler to cool and then enters the main compressor to increase its pressure. The working fluid at the outlet of the main compressor first enters the cryogenic regenerator to absorb heat and increase its temperature, and then merges with the working fluid at the outlet of the recompressor. Together, they enter the high-temperature regenerator and the heat storage tank to be heated, completing the cryogenic stage working fluid power generation cycle.

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