Energy storage system and power generation system

Abstract

The utility model relates to the technical field of energy recovery, in particular to an energy storage system and a power generation system, the energy storage system comprises at least two energy storage tanks used for storing energy storage media, the at least two energy storage tanks comprise a first energy storage tank and a second energy storage tank, and the temperature of the first energy storage tank is smaller than or equal to that of the second energy storage tank; a first heat storage passage is arranged between an outlet of the first energy storage tank and an inlet of the second energy storage tank, and a first heat exchanger is arranged on the first heat storage passage; the energy storage system further comprises a waste heat recovery device, and a waste heat medium inlet of the waste heat recovery device is communicated with a waste heat medium outlet of the first heat exchanger. According to the energy storage system, low-grade waste heat is fully absorbed through the waste heat recovery device, so that the problems that the working range of an existing energy storage system is limited, the low-grade waste heat cannot be fully absorbed while high-grade electric energy is absorbed and medium-and-high-grade steam is output, and energy is wasted are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy recovery, in particular to an energy storage system and a power generation system. Background Art

[0002] Energy storage systems are often used to absorb high-grade electricity in power generation systems or low-grade waste heat in industrial systems. Energy storage systems generally use energy storage media to store and convert energy. Existing energy storage media include molten salts, various alloys, etc.

[0003] For different scenarios, it is usually necessary to select appropriate energy storage media in combination with production needs. Taking molten salt as an example, the working temperature of commonly used molten salts is relatively limited. The minimum working temperature of molten salts with higher limit working temperatures is also relatively high. If molten salts with higher limit working temperatures are used as energy storage media, high-grade surplus electricity can be absorbed and medium- and high-grade steam can be output. However, due to the high minimum working temperature of molten salts, industrial waste heat cannot be fully absorbed. If molten salts with lower limit working temperatures are used as energy storage media, although industrial waste heat can be fully absorbed, high-grade steam cannot be output. Utility Model Content

[0004] The embodiments of the utility model provide an energy storage system and a power generation system to solve the problem that the existing energy storage system has a limited working range and cannot fully absorb low-grade waste heat while absorbing high-grade electrical energy and outputting medium- and high-grade steam, thereby causing energy waste.

[0005] An embodiment of the utility model provides an energy storage system, which includes at least two energy storage tanks for storing energy storage medium, the at least two energy storage tanks include a first energy storage tank and a second energy storage tank, the temperature of the first energy storage tank is less than or equal to that of the second energy storage tank; a first heat storage passage is provided between the outlet of the first energy storage tank and the inlet of the second energy storage tank, and a first heat exchanger is provided on the first heat storage passage; the energy storage system also includes a waste heat recovery device, and the waste heat medium inlet of the waste heat recovery device is connected to the waste heat medium outlet of the first heat exchanger.

[0006] By adopting the above technical solution, after the waste heat medium exchanges heat with the energy storage medium in the first heat exchanger, the waste heat medium with reduced temperature enters the waste heat recovery device, and the remaining part of the usable heat in the waste heat medium is recovered by means of the waste heat recovery device. Compared with the existing energy storage system, this solution can fully absorb low-grade waste heat through the waste heat recovery device, thereby solving the problem that the existing energy storage system has a limited working range and cannot fully absorb low-grade waste heat while absorbing high-grade electricity and outputting medium- and high-grade steam, thereby causing energy waste.

[0007] Optionally, the waste heat recovery device includes a heat storage element, and a waste heat medium inlet of the heat storage element is connected to a waste heat medium outlet of the first heat exchanger.

[0008] By adopting the above technical solution, after the waste heat medium enters the heat storage component, the remaining part of itself can be stored in the heat storage component using waste heat, thereby fully absorbing low-grade waste heat to reduce energy waste.

[0009] Optionally, the waste heat recovery device further comprises a second heat exchanger, the heat exchange medium inlet of the second heat exchanger is connected to the heat exchange medium outlet of the heat storage element, and the heat exchange medium outlet of the second heat exchanger is connected to the heat exchange medium inlet of the heat storage element to form a circulation loop.

[0010] By adopting the above technical solution, a heat exchange circulation loop is formed between the second heat exchanger and the heat storage element. The heat exchange medium in the loop can exchange heat with the heat storage element, thereby transferring the heat stored in the heat storage element to the heat exchange medium. Then the heat exchange medium heats other low-temperature media in the second heat exchanger, thereby realizing waste heat utilization.

[0011] Optionally, a heat release passage is provided between the outlet of the second energy storage tank and the inlet of the first energy storage tank, a third heat exchanger is provided on the heat release passage, and a water supply inlet of the third heat exchanger is connected to a water supply outlet of the second heat exchanger.

[0012] By adopting the above technical solution, the heat exchange medium heats the feed water required for the heat release stage of the energy storage system in the second heat exchanger, thereby utilizing part of the waste heat remaining in the waste heat medium to heat the feed water, thereby improving the heat exchange efficiency of the energy storage system in the heat release stage.

[0013] Optionally, there are at least two heat storage components, and at least two of the heat storage components are arranged in parallel with each other, and the waste heat medium inlet of each heat storage component is connected to the waste heat medium outlet of the first heat exchanger, and the heat exchange medium outlet of each heat storage component is connected to the heat exchange medium inlet of the second heat exchanger, and the heat exchange medium inlet of each heat storage component is connected to the heat exchange medium outlet of the second heat exchanger.

[0014] By adopting the above technical solution, each heat storage element can form an independent heat exchange circulation loop with the second heat exchanger. When one heat storage element is releasing heat, the other heat storage elements can store heat at the same time, so that at least two heat storage elements can operate alternately with each other, thereby realizing the heat storage and heat release processes at the same time.

[0015] And expand the scope of application of energy storage systems.

[0016] Optionally, a regulating valve is provided at the waste heat medium inlet and / or the heat exchange medium inlet of each heat storage element, and the regulating valve is used to adjust the flow or on-off of the medium in the heat storage passage or heat release passage in the heat storage element to adjust the working mode of the heat storage element.

[0017] By adopting the above technical solution, the regulating valve is used to control the flow or on-off of the medium in the heat storage passage or the heat release passage in the heat storage element, so that each heat storage element can form a mutually independent heat exchange passage, thereby realizing the heat storage and heat release processes at the same time, thereby expanding the scope of application of the energy storage system.

[0018] Optionally, the waste heat recovery device also includes a first driving member, the inlet of the first driving member is connected to the heat exchange medium outlet of the second heat exchanger, the outlet of the first driving member is connected to the heat exchange medium inlet of each of the heat storage members, and the first driving member is used to drive the heat exchange medium to circulate.

[0019] By adopting the above technical solution, the first driving member provides power for the circulating flow of the heat exchange medium, thereby accelerating the flow of the heat exchange medium and further improving the heat exchange efficiency.

[0020] Optionally, the energy storage system further includes a first heater, which is disposed between the first heat exchanger and the second energy storage tank, and a heat storage medium outlet of the first heater is connected to an inlet of the second energy storage tank.

[0021] By adopting the above technical solution, the first heater can continue to heat the energy storage medium discharged from the first heat exchanger, thereby further absorbing energy, and storing the energy in the second energy storage tank to achieve energy recovery and storage.

[0022] Optionally, at least two of the energy storage tanks further include a third energy storage tank for storing energy storage medium, and the temperature of the third energy storage tank is between that of the first energy storage tank and the second energy storage tank; the third energy storage tank and the first heat exchanger are arranged in series on the first heat storage passage, and the inlet of the third energy storage tank is connected to the energy storage medium outlet of the first heat exchanger.

[0023] By adopting the above technical solution, the third energy storage tank is used to store energy storage medium whose temperature is between that of the first energy storage tank and the second energy storage tank, thereby expanding the application scope of the energy storage system.

[0024] Optionally, a second heat storage passage is further provided between the outlet of the first energy storage tank and the inlet of the second energy storage tank, the second heat storage passage is provided in parallel with the first heat storage passage, and the energy storage medium in the first heat storage passage and the energy storage medium in the second heat storage passage are pre-mixed before entering the first heater.

[0025] By adopting the above technical solution, the energy storage medium in the first heat storage passage is pre-mixed with the energy storage medium in the second heat storage passage, and the energy storage medium in the first heat storage passage is heated by the energy storage medium in the second heat storage passage, thereby reducing the energy consumption of the first heater.

[0026] Optionally, a third heat storage passage is further provided between the outlet of the first energy storage tank and the inlet of the second energy storage tank, the third heat storage passage is provided in parallel with the first heat storage passage, the first heater is provided on the first heat storage passage, and the energy storage medium inlet of the first heater is connected to the outlet of the third energy storage tank; the energy storage system further includes a second heater, and the second heater is provided on the third heat storage passage.

[0027] By adopting the above technical solution, heaters are respectively arranged on the first heat storage passage and the third heat storage passage, so as to accurately control the temperature of the energy storage medium in each heat storage passage, thereby improving the accuracy and stability of the temperature control of the energy storage system.

[0028] Optionally, there are at least two first heat storage pathways, and the at least two first heat storage pathways are arranged in parallel, and the first heat exchanger and the third energy storage tank are arranged in series on each of the first heat storage pathways.

[0029] By adopting the above technical solution, multiple first heat storage paths can respectively recover usable waste heat in waste heat media of different types or temperatures, thereby expanding the application scope of the energy storage system.

[0030] Optionally, at least one of the first heat storage passages is provided with at least two third energy storage tanks with different temperatures in series, the first heat exchanger is provided between the first energy storage tank and the third energy storage tank adjacent to the first energy storage tank, and the first heat exchanger is provided between two adjacent third energy storage tanks.

[0031] By adopting the above technical solution, multiple third energy storage tanks and first heat exchangers are arranged in series on a first heat storage path to recover the usable waste heat in waste heat media of multiple different temperatures, thereby realizing the step-by-step recovery and utilization of energy and expanding the scope of application of the energy storage system.

[0032] Optionally, the heater used in the energy storage system is an electric heater.

[0033] By adopting the above technical solution, the excess electric energy in each power system can be used to directly provide working energy for the heater to absorb high-quality surplus electricity, thereby realizing energy storage and reducing energy waste.

[0034] Optionally, the energy storage system further includes a photovoltaic power station and / or a wind power station, and the photovoltaic power station and / or the wind power station are electrically connected to the electric heater.

[0035] By adopting the above technical solution, the energy storage system is combined with a photovoltaic power station or a wind power station. The excess electric energy produced by the photovoltaic power station or the wind power station can be used to heat the energy storage medium, so that the excess electric energy produced by the photovoltaic power station or the wind power station can be converted into heat and stored in the energy storage medium, and then utilized in the heat release stage, thereby realizing energy recovery and utilization.

[0036] Optionally, the heater used in the energy storage system is a solar thermal collector; the solar thermal collector directly heats the energy storage medium; or the solar thermal collector indirectly heats the energy storage medium via a heat-conducting medium.

[0037] By adopting the above technical solution, the heater is set as a solar collector, and the energy storage medium is heated by solar energy, thereby absorbing solar energy to achieve energy recovery and utilization.

[0038] Optionally, there are at least two third heat exchangers, and at least two third heat exchangers are arranged in series in the heat release passage; the water supply inlet of the third heat exchanger close to the first energy storage tank is connected to the water supply outlet of the second heat exchanger.

[0039] By adopting the above technical solution, during the heat release stage of the energy storage system, the energy storage medium passes through each third heat exchanger in turn and heats the feed water, thereby realizing the cascade utilization of energy, improving the energy utilization efficiency, and reducing energy waste.

[0040] Optionally, the heat of the waste heat medium comes from industrial waste heat.

[0041] By adopting the above technical solution, in the industrial production process, industrial materials with usable waste heat are exchanged with energy storage media, and the usable waste heat is stored in the energy storage media and utilized, thereby realizing energy recovery and reducing energy waste.

[0042] Optionally, it also includes a synthetic ammonia system, and the waste heat medium is the synthesis gas generated by the synthetic ammonia system.

[0043] By adopting the above technical solution, the third energy storage tank and the waste heat recovery device are used to recover the usable waste heat in the synthesis gas generated in the field of synthetic ammonia, and it is utilized in the heat release stage of the energy storage system, thereby realizing energy recovery and reducing energy waste.

[0044] Optionally, at least one of the first energy storage tank, the second energy storage tank and the third energy storage tank is provided with a thermal insulation structure.

[0045] By adopting the above technical solution and providing a heat preservation structure on the energy storage tank, heat loss inside the energy storage tank can be reduced in a low temperature or cold environment, thereby reducing energy waste.

[0046] The utility model also provides a power generation system, which comprises a steam turbine generator set and the above energy storage system, wherein the superheated steam outputted by the energy storage system in the heat release stage drives the steam turbine generator set to generate electricity.

[0047] By adopting the above technical solution, the energy storage system heats the feed water into superheated steam during the heat release stage, and the superheated steam is supplied to the steam turbine generator set for power generation, thereby realizing heat recovery and utilization; when power systems such as photovoltaic power stations or wind power stations are combined with energy storage systems, the excess electric energy produced by the power system can be converted into heat and stored in the energy storage medium. At peak power consumption times, the energy storage medium heats the feed water into superheated steam to drive the steam turbine generator set to generate electricity, thereby playing a role in peak shaving and valley filling and system frequency modulation, providing flexibility for power supply.

[0048] Compared with the prior art, the present invention has at least the following advantages:

[0049] First, after the waste heat medium exchanges heat with the energy storage medium in the first heat exchanger, the waste heat medium with reduced temperature enters the waste heat recovery device, and the remaining usable heat in the waste heat medium is recovered by means of the waste heat recovery device. Compared with the existing energy storage system, this solution can fully absorb low-grade waste heat through the waste heat recovery device, thereby solving the problem that the existing energy storage system has a limited working range and cannot fully absorb low-grade waste heat while absorbing high-grade electricity and outputting medium- and high-grade steam, thereby causing energy waste.

[0050] Second, the heat exchange medium heats the feed water required for the heat release stage of the energy storage system in the second heat exchanger, so that the remaining part of the waste heat medium can use the waste heat to heat the feed water to improve the heat exchange efficiency of the energy storage system in the heat release stage.

[0051] Third, the waste heat recovery device includes at least two heat storage elements, each of which can form an independent heat exchange circulation loop with the second heat exchange element. When one of the heat storage elements is releasing heat, the other heat storage elements can store heat at the same time, so that at least two heat storage elements can operate alternately with each other, thereby realizing the heat storage and heat release processes at the same time, thereby expanding the scope of application of the energy storage system.

[0052] Fourth, industrial equipment usually needs to continue to operate after it is turned on, so industrial waste heat is usually generated continuously. The energy storage system in this case can fully absorb industrial waste heat through the third energy storage tank and the waste heat recovery device, and is not affected by the volatility of renewable energy. For example, the photovoltaic power station heats the energy storage medium through the heat storage path during the day. When the photovoltaic power station stops working at night, it cannot continuously store heat, but industrial waste heat is still continuously generated at night. Therefore, the third energy storage tank and the waste heat recovery device can be used to continuously absorb industrial waste heat, so that the heat storage and heat release processes can be carried out simultaneously, thereby broadening the applicability of the system.

[0053] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for describing the embodiments are briefly introduced below.

[0055] Figure 1 A schematic diagram of the operation of an energy storage system provided by an embodiment of the utility model;

[0056] Figure 2 A schematic diagram of another energy storage system provided in an embodiment of the utility model;

[0057] Figure 3 A schematic diagram of another energy storage system provided in an embodiment of the utility model;

[0058] Figure 4 A schematic diagram of another energy storage system provided in an embodiment of the utility model;

[0059] Figure 5 A schematic diagram of the operation of another energy storage system provided in an embodiment of the utility model. Description of the drawings:

[0061] 1. The first energy storage tank; 2. The third energy storage tank; 3. The second energy storage tank; 4. The first heat exchanger; 51. The first heater; 52. The second heater; 6. The waste heat recovery device; 61. The second heat exchanger; 62. The heat storage component; 63. The first driving component; 71. The feed water-molten salt heat exchanger; 72. The saturated steam-molten salt heat exchanger; 81. The first regulating valve; 82. The second regulating valve; 83. The third regulating valve; 84. The fourth regulating valve; 85. The fifth regulating valve; 86. The sixth regulating valve; 91. The first delivery pump; 92. The second delivery pump; 93. The third delivery pump. DETAILED DESCRIPTION

[0062] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can also be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0063] Reference Figure 1 and Figure 2The embodiment of the utility model provides an energy storage system, which can be applied to industrial heating, steam power generation, deep peak regulation of thermal power units, photovoltaic power generation and wind power generation, etc., and comprises at least two energy storage tanks for storing energy storage medium, and the at least two energy storage tanks comprise a first energy storage tank 1 and a second energy storage tank 3, and the temperature of the first energy storage tank 1 is less than or equal to that of the second energy storage tank 3; a first heat storage passage is provided between the outlet of the first energy storage tank 1 and the inlet of the second energy storage tank 3, and a first heat exchanger 4 is provided on the first heat storage passage; the energy storage system further comprises a waste heat recovery device 6, and the waste heat medium inlet of the waste heat recovery device 6 is connected to the waste heat medium outlet of the first heat exchanger 4.

[0064] Specifically, in the energy field, energy with strong work capacity is called high-grade energy, such as mechanical energy and electrical energy, which can be completely converted into work, and belong to high-grade energy; on the contrary, energy with weak work capacity is called low-grade energy, such as thermal energy, which can only be partially converted into work, and belongs to low-grade energy. In the field of waste heat recovery, high temperature means that the waste heat resource has high work capacity, that is, the so-called "high-grade waste heat resource", and low temperature means that the waste heat resource has weak work capacity, that is, the so-called "low-grade waste heat resource". Low-grade waste heat resources generally refer to waste heat energy with low concentration and low energy.

[0065] Molten salt is a commonly used energy storage medium in production. In order to clearly describe the technical solution of this application, the energy storage medium in the following text is molten salt. However, it should be understood that in addition to molten salt, heat transfer oil and other energy storage media that meet the working temperature requirements can be used as the energy storage medium in this utility model.

[0066] In addition, the waste heat medium in the embodiment of the present application can be any one of liquid, solid or gas, or a mixture of liquid, solid or gas. The embodiment of the present application does not limit the source of the waste heat medium, as long as it contains usable waste heat. In this embodiment, there can be two or three energy storage tanks, which are not limited in the embodiment of the present application, and those skilled in the art can flexibly set them according to actual needs.

[0067] In some embodiments, Figure 1 As shown, there are two energy storage tanks, namely the first energy storage tank 1 and the second energy storage tank 2, wherein each energy storage tank has an inlet and an outlet for energy storage medium to enter and exit. The first heat exchanger 4 has a waste heat medium inlet, a waste heat medium outlet, an energy storage medium inlet and an energy storage medium outlet, and the waste heat recovery device 6 has a waste heat medium outlet and a waste heat medium inlet.

[0068] When the energy storage system is storing heat, the molten salt in the first energy storage tank 1 enters the first heat exchanger 4, exchanges heat with the waste heat medium in the first heat exchanger 4, and is directly stored in the second energy storage tank 3; after the waste heat medium exchanges heat with the molten salt in the first heat exchanger 4, it is discharged from the first heat exchanger 4 and then enters the waste heat recovery device 6, which recovers the remaining part of the waste heat medium.

[0069] The final waste heat medium is discharged from the waste heat recovery device 6.

[0070] In other embodiments, Figure 2 As shown, there are three energy storage tanks, namely a first energy storage tank 1, a second energy storage tank 2, and a third energy storage tank 3, wherein each energy storage tank has an inlet and an outlet for energy storage medium to enter and exit, the first heat exchanger 4 has a waste heat medium inlet, a waste heat medium outlet, an energy storage medium inlet and an energy storage medium outlet, and the waste heat recovery device 6 has a waste heat medium outlet and a waste heat medium inlet.

[0071] When the energy storage system stores heat, Figure 2 In the process shown by the solid line, the molten salt in the first energy storage tank 1 is discharged in two ways, one of which directly enters the first heater 51, and the molten salt is heated by the first heater 51 and directly enters the second energy storage tank 3; the other molten salt enters the first heat exchanger 4, and after heat exchange with the waste heat medium in the first heat exchanger 4, it directly enters the third energy storage tank 2, and then the molten salt in the third energy storage tank 2 enters the first heater 51 and is heated, and finally stored in the second energy storage tank 3; the waste heat medium exchanges heat with the molten salt in the first heat exchanger 4, and then is discharged from the first heat exchanger 4, and then enters the waste heat recovery device 6, and the waste heat recovery device 6 recovers the remaining part of the waste heat medium. The waste heat medium is finally discharged from the waste heat recovery device 6. Among them, the first heater 51 can be an electric heater, so that electric energy can be used to provide energy for heating the molten salt.

[0072] When the energy storage system releases heat, execute Figure 2 In the process shown by the middle dotted line, the molten salt in the second energy storage tank 3 passes through the saturated steam-molten salt heat exchanger 72 and the feed water-molten salt heat exchanger 71 in turn, and the feed water is heated into superheated steam. The molten salt eventually flows back to the first energy storage tank 1, and the superheated steam is transported to the heat utilization site.

[0073] This embodiment uses the waste heat recovery device 6 to recover the remaining usable heat in the waste heat medium. Compared with the existing energy storage system, this solution can absorb high-grade electric energy and output medium-high grade steam through the second energy storage tank 3, and fully absorb low-grade waste heat through the third energy storage tank 2 and the waste heat recovery device 6, thereby solving the problem that the existing energy storage system has a limited working range and cannot fully absorb low-grade waste heat while absorbing high-grade electric energy and outputting medium-high grade steam, thereby causing energy waste.

[0074] It should be noted that, in actual operation, due to heat loss in the pipeline, insufficient available heat in the waste heat medium, and a decrease in the temperature of the energy storage medium pre-stored in the second energy storage tank 3, the temperature of the second energy storage tank 3 may be equal to the temperature of the first energy storage tank 1.

[0075] Optionally, in a specific embodiment, referring to Figure 3 The waste heat recovery device 6 includes a heat storage component 62 , and a waste heat medium inlet of the heat storage component 62 is connected to a waste heat medium outlet of the first heat exchanger 4 .

[0076] Specifically, the heat storage element 62 has a waste heat medium inlet, a waste heat medium outlet, a heat exchange medium inlet and a heat exchange medium outlet, and the heat storage element 62 can absorb heat and temporarily store it in itself. The waste heat medium inlet of the heat storage element 62 is connected to the waste heat medium outlet of the first heat exchanger 4.

[0077] In this embodiment, the waste heat medium takes the synthesis gas produced in the chemical industry as an example, but it should be understood that, in addition to synthesis gas, waste gas and waste liquid with usable waste heat generated in the industrial production process can all be used as the waste heat medium in the utility model, such as the high-temperature steam produced by power plants for power generation or the hot flue gas discharged by steel mills.

[0078] When the waste heat recovery device 6 is working, the temperature of the synthesis gas decreases after heat exchange with the molten salt in the first heat exchanger 4, and then the synthesis gas is passed into the heat storage component 62. The synthesis gas heats the heat storage component 62, thereby storing part of the residual heat in the synthesis gas in the heat storage component 62, and finally the synthesis gas is discharged from the heat storage component 62.

[0079] In this embodiment, the heat storage element 62 is used to store part of the residual heat in the residual heat medium, so as to fully absorb the low-grade residual heat and reduce energy waste. In addition, the residual heat in the residual heat medium is absorbed by temporary storage, so that the energy storage system can flexibly release heat according to demand, thereby broadening the application scope of the energy storage system.

[0080] Optionally, in a specific embodiment, referring to Figure 3 The waste heat recovery device 6 also includes a second heat exchanger 61, the heat exchange medium inlet of the second heat exchanger 61 is connected to the heat exchange medium outlet of the heat storage element 62, and the heat exchange medium outlet of the second heat exchanger 61 is connected to the heat exchange medium inlet of the heat storage element 62 to form a circulation loop.

[0081] Specifically, the second heat exchanger 61 has a heat exchange medium outlet and a heat exchange medium inlet, and the second heat exchanger 61 and the heat storage element 62 form a heat exchange circulation loop.

[0082] The heat exchange medium can be any one of liquid, solid or gas, or a mixture of liquid, solid or gas. The embodiment of the present application does not limit the type of heat exchange medium, as long as it can flow in the heat exchange cycle.

[0083] In this embodiment, a heat exchange circulation loop is formed between the second heat exchanger 61 and the heat storage element 62. The heat exchange medium in the loop can exchange heat with the heat storage element 62, thereby transferring the heat stored in the heat storage element 62 to the heat exchange medium. Then the heat exchange medium heats other low-temperature media in the second heat exchanger 61, thereby realizing waste heat utilization.

[0084] Optionally, in a specific embodiment, referring to Figure 3 A heat release passage is provided between the outlet of the second energy storage tank 3 and the inlet of the first energy storage tank 1 , and the heat release passage is provided with a third heat exchanger, and the water supply inlet of the third heat exchanger is connected to the water supply outlet of the second heat exchanger 61 .

[0085] Specifically, the third heat exchanger includes a saturated steam-molten salt heat exchanger 72 and a feed water-molten salt heat exchanger 71, which are connected in series on the heat release path. The feed water outlet of the second heat exchanger 61 is connected to the feed water inlet of the feed water-molten salt heat exchanger 71.

[0086] When the energy storage system releases heat, the heat exchange medium first exchanges heat with the heat storage element 62 , and then flows into the second heat exchanger 61 and exchanges heat with the feed water, thereby indirectly storing the heat in the waste heat medium in the feed water, and finally the heat exchange medium with reduced temperature flows back to the heat storage element 62 .

[0087] In this embodiment, the heat exchange medium heats the feed water required for the heat release stage of the energy storage system in the second heat exchanger 61, thereby utilizing the waste heat in the waste heat medium to heat the feed water to improve the heat exchange efficiency of the energy storage system in the heat release stage.

[0088] Optionally, in a specific embodiment, referring to Figure 3 There are at least two heat storage components 62, and at least two heat storage components 62 are arranged in parallel with each other. The waste heat medium inlet of each heat storage component 62 is connected to the waste heat medium outlet of the first heat exchanger 4, and the heat exchange medium outlet of each heat storage component 62 is connected to the heat exchange medium inlet of the second heat exchanger 61, and the heat exchange medium inlet of each heat storage component 62 is connected to the heat exchange medium outlet of the second heat exchanger 61.

[0089] Specifically, the number of heat storage elements 62 can be flexibly set according to actual needs, and the embodiment of the present application does not limit it. At least two heat storage elements 62 are set in parallel to achieve simultaneous heat storage and heat release.

[0090] In this embodiment, taking two heat storage components 62 as an example, the waste heat medium inlets of the two heat storage components 62 are connected to the waste heat medium outlet of the first heat exchanger 4, and the heat exchange medium outlets of the two heat storage components 62 are connected to the heat exchange medium inlet of the second heat exchanger 61, and a circulation loop for the flow of heat exchange medium can be formed between each heat storage component 62 and the second heat exchanger 61.

[0091] When the waste heat recovery device 6 is working, the first heat storage component 62 is connected to the first heat exchanger 4 and disconnected from the second heat exchanger 61. The heat storage component 62 exchanges heat with the waste heat medium, thereby storing the remaining heat in the waste heat medium in the heat storage component 62; the second heat storage component 62 is disconnected from the first heat exchanger 4 and connected to the second heat exchanger 61. The heat storage component 62 exchanges heat with the heat exchange medium, and then the heat exchange medium exchanges heat with the feed water to indirectly store the heat in the waste heat medium in the feed water. After the temperature of the second heat storage component 62 is lowered, the second heat storage component 62 is connected to the first heat exchanger 4 and disconnected from the second heat exchanger 61, and the first heat storage component 62 is disconnected from the first heat exchanger 4 and connected to the second heat exchanger 61, so that the two heat storage components 62 can operate alternately to simultaneously realize the heat storage and heat release processes.

[0092] In this embodiment, each heat storage element 62 can form an independent heat exchange circulation loop with the second heat exchanger 61. When one heat storage element 62 releases heat, the other heat storage elements 62 can store heat at the same time, so that at least two heat storage elements 62 can operate alternately with each other, thereby realizing the heat storage and heat release processes at the same time, thereby expanding the scope of application of the energy storage system.

[0093] Optionally, in a specific embodiment, referring to Figure 3 A regulating valve is provided at the waste heat medium inlet and / or the heat exchange medium inlet of the heat storage component 62, and the regulating valve is used to adjust the flow rate or on-off of the medium in the heat storage passage or the heat release passage in the heat storage component 62 to adjust the working mode of the heat storage component 62.

[0094] Specifically, when there are two heat storage elements 62, a first regulating valve 81 and a second regulating valve 82 may be respectively provided at the waste heat medium inlets of the two heat storage elements 62, or a third regulating valve 83 and a fourth regulating valve 84 may be respectively provided at the heat exchange medium inlets of the two heat storage elements 62.

[0095] In this embodiment, a regulating valve is used to control the flow rate and on-off of the medium in the flow path, so that the two heat storage components 62 can form independent heat exchange paths, so that the heat storage components 62 can freely switch between the two working modes of heat storage and heat release, and can also realize heat storage and heat release at the same time, thereby expanding the scope of application of the energy storage system.

[0096] Optionally, in a specific embodiment, referring to Figure 3The waste heat recovery device 6 also includes a first driving member 63, the inlet of the first driving member 63 is connected to the heat exchange medium outlet of the second heat exchanger 61, and the outlet of the first driving member 63 is connected to the heat exchange medium inlet of each of the heat storage members 62, and the first driving member 63 is used to drive the heat exchange medium to circulate.

[0097] Specifically, the first driving member 63 provides power for the circulation of the heat exchange medium to improve the heat storage and heat release efficiency of the waste heat recovery device 6 .

[0098] In addition, the specific type of the first driving member 63 can be selected according to the type of heat exchange medium. For example, when the heat exchange medium is gas, the first driving member 63 can be a circulating fan, and when the heat exchange medium is liquid, the first driving member 63 can be a circulating pump.

[0099] Optionally, in a specific embodiment, referring to Figure 2 and Figure 3 The energy storage system further includes a first heater 51 , which is disposed between the first heat exchanger 4 and the second energy storage tank 3 , and a heat storage medium outlet of the first heater 51 is connected to an inlet of the second energy storage tank 3 .

[0100] Specifically, the first heater 51 can continue to heat the energy storage medium discharged from the first heat exchanger 4, thereby further absorbing energy, and storing the energy in the second energy storage tank 3 to achieve energy recovery and storage.

[0101] Optionally, in a specific embodiment, referring to Figure 2 and Figure 3 At least two of the energy storage tanks further include a third energy storage tank 2 for storing energy storage medium, and the temperature of the third energy storage tank 2 is between the first energy storage tank 1 and the second energy storage tank 3; the third energy storage tank 2 and the first heat exchanger 4 are arranged in series on the first heat storage passage, and the inlet of the third energy storage tank 2 is connected to the energy storage medium outlet of the first heat exchanger 4.

[0102] Specifically, the third energy storage tank 2 is used to store energy storage medium whose temperature is between that of the first energy storage tank 1 and the second energy storage tank 3, thereby expanding the application scope of the energy storage system.

[0103] Optionally, in a specific embodiment, referring to Figure 2 and Figure 3 A second heat storage passage is also provided between the outlet of the first energy storage tank 1 and the inlet of the second energy storage tank 3. The second heat storage passage is provided in parallel with the first heat storage passage. The energy storage medium in the first heat storage passage and the energy storage medium in the second heat storage passage are pre-mixed before entering the first heater 4.

[0104] Specifically, Figure 2 This is a schematic diagram of the operation of an energy storage system provided in an embodiment of the present application; when the energy storage system stores heat, its operation process is as follows Figure 2 As shown by the solid line in , the molten salt in the first energy storage tank 1 is discharged in two ways, one of which directly enters the first heater 51, is directly heated in the first heater 51 and is stored in the second energy storage tank 3; the other molten salt first enters the first heat exchanger 4, and at the same time, the waste heat medium is passed into the first heat exchanger 3, the waste heat medium exchanges heat with the molten salt, heats the molten salt and stores it in the third energy storage tank 2, and then the molten salt in the third energy storage tank 2 is heated by the first heater 51 and stored in the third energy storage tank 2, and the waste heat medium with reduced temperature is discharged from the first heater 51 and enters the waste heat recovery device 6.

[0105] In this embodiment, the energy storage medium in the first heat storage passage is pre-mixed with the energy storage medium in the second heat storage passage, and the energy storage medium in the first heat storage passage is heated by the energy storage medium in the second heat storage passage, thereby reducing the energy consumption of the first heater 51.

[0106] Optionally, in a specific embodiment, referring to Figure 4 A third heat storage passage is provided between the outlet of the first energy storage tank 1 and the inlet of the second energy storage tank 3, the third heat storage passage is provided in parallel with the first heat storage passage, the first heater 51 is provided on the first heat storage passage, the energy storage medium inlet of the first heater 51 is connected to the outlet of the third energy storage tank 2; the energy storage system further includes a second heater 52, and the second heater 52 is provided on the third heat storage passage.

[0107] Specifically, Figure 4 This is a schematic diagram of another energy storage system provided in an embodiment of the present application; when the energy storage system stores heat, its operation process is as follows Figure 4 As shown by the solid line in , the molten salt in the first energy storage tank 1 is discharged in two ways, one of which directly enters the second heater 52, is heated in the second heater 52 and is stored in the second energy storage tank 3; the other molten salt first enters the first heat exchanger 4, and the waste heat medium is passed into the first heat exchanger 4, the waste heat medium exchanges heat with the molten salt, and the molten salt is heated and stored in the third energy storage tank 2, and then the molten salt in the third energy storage tank 2 is heated by the first heater 51 and stored in the second energy storage tank 3.

[0108] The waste heat medium with reduced temperature is output from the first heat exchanger 4 and enters the waste heat recovery device 6 . The waste heat recovery device 6 recovers the remaining part of the waste heat in the waste heat medium, and finally the waste heat medium is discharged from the waste heat recovery device 6 .

[0109] When the energy storage system releases heat, its operation process is as follows: Figure 4As shown by the middle dotted line, the molten salt in the second energy storage tank 3 passes through the saturated steam-molten salt heat exchanger 72 and the feed water-molten salt heat exchanger 71 in sequence, heating the feed water into superheated steam, and finally the superheated steam is discharged to the heat utilization site, while the molten salt flows back to the first energy storage tank 1.

[0110] In this embodiment, heaters are respectively provided on the first heat storage passage and the third heat storage passage, so as to accurately control the temperature of the energy storage medium in each heat storage passage, thereby improving the accuracy and stability of the temperature control of the energy storage system.

[0111] Optionally, in a specific embodiment, there are at least two first heat storage pathways, at least two of the first heat storage pathways are arranged in parallel, and each of the first heat storage pathways is provided with the first heat exchanger 4 and the third energy storage tank 2 in series.

[0112] Specifically, the number of first heat storage paths can be flexibly set according to the number of types of waste heat media at different temperatures; for example, when it is necessary to recover waste heat in two waste heat media at different temperatures, two first heat storage paths can be set, and the two first heat storage paths are arranged in parallel. A first heat exchanger 4 and a third energy storage tank 2 are arranged in series on each first heat storage path. The waste heat medium and the molten salt are exchanged with the help of the first heat exchanger 4, and the molten salt is heated and stored in the third energy storage tank 2 on the corresponding path. Then, the molten salt discharged from the third energy storage tank 2 is heated by the first heater 51 and stored in the second energy storage tank 3, thereby realizing the storage of usable waste heat.

[0113] In this embodiment, the plurality of first heat storage paths can respectively recover the usable waste heat in waste heat media of different types or temperatures, thereby expanding the application scope of the energy storage system.

[0114] Optionally, in a specific embodiment, at least one of the first heat storage passages is provided in series with at least two third energy storage tanks 2 with different temperatures, the first heat exchanger 4 is provided between the first energy storage tank 1 and the third energy storage tank 2 adjacent to the first energy storage tank 1, and the first heat exchanger 4 is provided between two adjacent third energy storage tanks 2.

[0115] Specifically, the number of third energy storage tanks 2 on each first heat storage path can be flexibly selected according to the number and types of waste heat media at different temperatures. The storage temperatures of the multiple third energy storage tanks 2 are different. The storage temperature of the third energy storage tank 2 adjacent to the first energy storage tank 1 is the lowest, and the storage temperature of the third energy storage tank 2 close to the second energy storage tank 3 is the highest. The storage temperatures of the remaining third energy storage tanks 2 increase one by one along the flow direction of the molten salt.

[0116] For example, when a first heat storage passage is used to recover industrial waste heat of two different temperatures, two third energy storage tanks 2 with different storage temperatures can be arranged on the first heat storage passage. The two third energy storage tanks 2 are arranged in series on the first heat storage passage. The storage temperature of the third energy storage tank 2 adjacent to the first energy storage tank 1 is lower, while the storage temperature of the second energy storage tank 2 close to the third energy storage tank 3 is higher. A first heat exchanger 4 is arranged between the first energy storage tank 1 and the third energy storage tank 2 adjacent to the first energy storage tank 1, and a first heat exchanger 4 is also arranged between the two third energy storage tanks 2.

[0117] During heat storage, the industrial waste heat with a lower temperature is passed into the first heat exchanger 4 close to the first energy storage tank 1, and the industrial waste heat with a higher temperature is passed into another first heat exchanger 4; the molten salt first passes through the first first heat exchanger 4, is heated in the first first heat exchanger 4 and stored in the third energy storage tank 2, and then the molten salt discharged from the third energy storage tank 2 is heated by the industrial waste heat with a higher temperature in the second first heat exchanger 4, and then is stored in the third energy storage tank 2 close to the second energy storage tank 3.

[0118] In the embodiment of the present application, a plurality of third energy storage tanks 2 and a first heat exchanger 4 are arranged in series on a first heat storage path to recover the usable waste heat in waste heat media of various temperatures, thereby realizing the step-by-step recovery and utilization of energy and expanding the scope of application of the energy storage system.

[0119] Optionally, in a specific embodiment, referring to Figure 2-Figure 4 The heater used in the energy storage system is an electric heater.

[0120] Specifically, at least one of the first heater 51 and the second heater 52 is set as an electric heater, so that the excess electric energy in each power system can be used to directly provide working energy for the first heater 51 or the second heater 52 to absorb high-quality surplus electricity.

[0121] Optionally, in a specific embodiment, the energy storage system further includes a photovoltaic power station and / or a wind power station, and the photovoltaic power station and / or the wind power station are electrically connected to the electric heater.

[0122] Specifically, when the first heater 51 is an electric heater, the first heater 51 can be provided with the electric energy required for operation by a photovoltaic power station or a wind power station, or by both the photovoltaic power station and the wind power station. When the second heater 52 is an electric heater, the second heater 52 can be provided with the electric energy required for operation by a photovoltaic power station or a wind power station, or by both the photovoltaic power station and the wind power station.

[0123] When the first heater 51 and the second heater 52 are both electric heaters, one of the heaters can be provided with the required electric energy for operation only by the photovoltaic power station, while the other heater can be provided with the required electric energy for operation only by the wind power station; in addition, at least one of the photovoltaic power station and the wind power station can also provide the required electric energy for operation of both heaters at the same time.

[0124] The embodiment of the present application combines a photovoltaic power station or a wind power station with an energy storage system, and uses the excess electricity produced by the photovoltaic power station or the wind power station to heat the molten salt to achieve energy storage and utilization, thereby

[0125] It can play the role of peak shaving and valley filling and system frequency regulation, providing flexibility for power supply.

[0126] In some embodiments, Figure 4 As shown, taking the combination of a photovoltaic power station and an energy storage system as an example, the first heater 51 and the second heater 52 are both electric heaters, and the photovoltaic power station provides the required electric energy for the first heater 51 and the second heater 52; during the daytime heat storage, the operation process of the energy storage system is as follows Figure 4 As shown by the solid line in , the molten salt is discharged in two ways, one of which is directly discharged to the second heater 52 to be heated and stored in the third energy storage tank 3; the other is discharged to the first heat exchanger 4 to be heated by the waste heat medium and stored in the third energy storage tank 2, and then the molten salt in the third energy storage tank 2 is heated by the first heater 51 and stored in the second energy storage tank 3. At the same time, the waste heat medium with reduced temperature enters the waste heat recovery device 6.

[0127] At night, when the photovoltaic power station stops working, the energy storage system executes Figure 4 In the heat release process shown by the middle dotted line, the waste heat recovery device 6 heats the feed water, and the molten salt in the second energy storage tank 3 passes through the saturated steam-molten salt heat exchanger 72 and the feed water-molten salt heat exchanger 71 in turn to heat the feed water into superheated steam, which is then sent to the steam turbine generator set to generate electricity, thereby providing electricity for other plant areas.

[0128] In addition, the wind power station can also be combined with the energy storage system, and the wind power station provides the required electric energy for the first heater 51 and the second heater 52; at this time, since the wind power station can also generate electricity at night, the heat storage process can also be performed at night, that is, the usable waste heat in the waste heat medium can be stored in the third energy storage tank 2 through the first heat exchanger 4, and then the molten salt is heated by the first heater 51 and stored in the second energy storage tank 3, thereby realizing energy storage.

[0129] In other embodiments, Figure 2 As shown, taking the combination of a photovoltaic power station and an energy storage system as an example, the first heater 51 is an electric heater, and the photovoltaic power station provides the required electric energy for the first heater 51; during the daytime heat storage, the operation process of the energy storage system is as follows Figure 2 As shown by the solid line in , the molten salt is discharged in two ways, one of which is directly discharged into the first heater 51 to be heated and stored in the second energy storage tank 3; the other is discharged into the first heat exchanger 4 to be heated by the waste heat medium and stored in the third energy storage tank 2. The molten salt in the third energy storage tank 2 is then mixed with the molten salt of the other way, and enters the first heater 51 together to be heated and stored in the second energy storage tank 3. At the same time, the waste heat medium with reduced temperature enters the waste heat recovery device 6.

[0130] At night, when the photovoltaic power station stops working, the energy storage system executes Figure 2 In the heat release process shown by the middle dotted line, the waste heat recovery device 6 heats the feed water, and the molten salt in the second energy storage tank 3 passes through the saturated steam-molten salt heat exchanger 72 and the feed water-molten salt heat exchanger 71 in turn to heat the feed water into superheated steam, which is then sent to the steam turbine generator set to generate electricity, thereby providing electricity for other plant areas.

[0131] In addition, when the output of new energy is insufficient or during the peak period of electricity consumption, the first heater 51 lacks power and cannot work, and the energy storage system can operate as follows: Figure 5 As shown in the solid line process, the molten salt in the first energy storage tank 1 is stored in the third energy storage tank 2 after heat exchange with the waste heat medium through the first heat exchanger 4. The waste heat medium after heat exchange enters the waste heat recovery device 6 to heat the feed water. Then the molten salt pre-stored in the second energy storage tank 3 enters the saturated steam-molten salt heat exchanger 72 and the feed water-molten salt heat exchanger 71 in sequence to heat the feed water into superheated steam, and the superheated steam is supplied to the steam turbine generator set for power generation.

[0132] This embodiment combines a photovoltaic power station or a wind power station with an energy storage system, and can convert the excess electricity generated by the photovoltaic power station during the day or the excess electricity generated by the wind power station into heat and store it in the third energy storage tank 2 and the second energy storage tank 3. At night or other times when electricity is used, the molten salt and water are exchanged to generate superheated steam to drive the turbine generator set to generate electricity, thereby achieving the effects of peak shaving and valley filling and system frequency modulation, and providing flexibility for power supply. In addition, in addition to using a photovoltaic power station or a wind power station to provide the heater with electricity for heating the molten salt, valley electricity from a thermal power station or other power systems can also be used to provide electricity for the heater.

[0133] Optionally, in a specific embodiment, the heater used in the energy storage system is a solar thermal collector; the solar thermal collector directly heats the energy storage medium; or, the solar thermal collector indirectly heats the energy storage medium via a heat-conducting medium.

[0134] Specifically, the first heater 51 is a solar collector, which can directly heat the molten salt. The solar collector can also be used to heat a heat-conducting medium such as thermal oil, and the molten salt is heated through the heat-conducting medium to absorb the low-grade energy produced by the solar collector, thereby realizing energy recovery and utilization.

[0135] In some embodiments, the second heater 52 is a solar thermal collector, which utilizes solar energy to heat the energy storage medium, thereby absorbing the solar energy to achieve energy recovery and utilization.

[0136] Optionally, in a specific embodiment, referring to Figure 2-Figure 4 There are at least two third heat exchangers, and at least two third heat exchangers are arranged in series in the heat release passage; the water supply inlet of the third heat exchanger close to the first energy storage tank 1 is connected to the water supply outlet of the second heat exchanger 61.

[0137] Specifically, there are two third heat exchangers, namely a feed water-molten salt heat exchanger 71 and a saturated steam-molten salt heat exchanger 72; wherein the feed water-molten salt heat exchanger 71 is arranged close to the first energy storage tank 1, and the saturated steam-molten salt heat exchanger 72 is arranged close to the second energy storage tank 3.

[0138] When releasing heat, the molten salt in the second energy storage tank 3 first enters the saturated steam-molten salt heat exchanger 72 to heat the saturated steam into superheated steam, and then the molten salt with reduced temperature enters the feed water-molten salt heat exchanger 71 to exchange heat with the feed water to heat the feed water into saturated steam.

[0139] In this embodiment, the two third heat exchangers are used to realize the cascade utilization of energy, thereby improving the energy utilization efficiency and reducing the energy waste.

[0140] Optionally, in a specific embodiment, referring to Figure 3 , the heat of the waste heat medium comes from industrial waste heat.

[0141] Specifically, the waste heat medium can be various substances containing usable waste heat generated in industry, and its specific state can be liquid, gaseous, solid, or a gas-liquid or solid-liquid mixture, which is not limited in the embodiments of the present application; in the industrial production process, industrial substances with usable waste heat are exchanged with molten salt, so that the usable waste heat is stored in the molten salt and utilized to reduce energy waste.

[0142] Optionally, in a specific embodiment, referring to Figure 3 , also includes a synthetic ammonia system, and the waste heat medium is the synthesis gas produced by the synthetic ammonia system.

[0143] Specifically, the low-grade industrial waste heat in this embodiment can come from the field of chemical synthesis ammonia. In the process of chemical synthesis ammonia, synthesis gas will be generated, and the synthesis gas will be passed into the first heat exchanger 4. The molten salt is heated by the synthesis gas and stored in the third energy storage tank 2, and the synthesis gas with reduced temperature is discharged to the waste heat recovery device 6 to heat the feed water. Finally, the synthesis gas is discharged from the energy storage system and returned to the chemical area.

[0144] In this embodiment, the usable waste heat in the synthesis gas is stored in the molten salt and used for subsequent power generation, thereby realizing energy recovery and reducing energy waste.

[0145] Optionally, in a specific embodiment, at least one of the first energy storage tank 1 , the third energy storage tank 2 and the second energy storage tank 3 is provided with a heat preservation structure.

[0146] Specifically, in low temperature or cold conditions, the energy storage tank will be exposed to the external environment for a long time, which will cause the heat inside the energy storage tank to be lost. Therefore, a thermal insulation structure can be set on the energy storage tank to reduce the heat loss inside the energy storage tank.

[0147] A thermal insulation structure may be provided on the outside of the energy storage tank or on the inside of the energy storage tank. To improve the thermal insulation effect, a thermal insulation structure may be provided on both the outside and the inside of the energy storage tank. For example, a thermal insulation structure similar to a heating pipe may be provided on the inner or outer wall of the energy storage tank, and a high-temperature thermal insulation medium may be passed into the heating pipe to reduce heat loss inside the energy storage tank. In addition, a thermal insulation structure similar to a thermal insulation layer may be coated on the inner or outer wall of the energy storage tank, or a heating wire may be provided on the inner or outer wall of the energy storage tank to reduce heat loss inside the energy storage tank.

[0148] In addition, the insulation medium in the insulation pipe can be one of the saturated steam, superheated steam or synthesis gas in the aforementioned embodiments, or a mixture of saturated steam, superheated steam or synthesis gas, wherein the synthesis gas can come from the synthetic ammonia section; the insulation medium containing usable waste heat is introduced into the insulation pipe, thereby reducing the heat loss inside the energy storage tank and realizing full utilization of the energy in the energy storage system.

[0149] Optionally, in a specific embodiment, referring to Figure 3 Among the first energy storage tank 1, the second energy storage tank 3 and the third energy storage tank 2, at least one of the energy storage tanks has a second driving member disposed at its outlet, and the second driving member is used to drive the energy storage medium to flow.

[0150] Specifically, the second driving member provides power for the circulation of the energy storage medium to improve the efficiency of heat storage and heat release of the energy storage device. The specific type of the second driving member can be selected according to the type of energy storage medium. For example, when the energy storage medium is gas, the second driving member can be a circulating fan, and when the energy storage medium is liquid, the second driving member can be a delivery pump.

[0151] In this embodiment, the energy storage medium takes molten salt as an example, and the second driving member is a delivery pump. A delivery pump may be provided at the outlet of each energy storage tank, or only at the outlet of one or two energy storage tanks, which is not limited in this embodiment.

[0152] In this embodiment, the on-off of the heat storage passage or the heat release passage and the flow rate of the molten salt can be controlled by the delivery pump, thereby controlling the working efficiency of the entire energy storage system.

[0153] like Figure 3 As shown, a first delivery pump 91, a second delivery pump 92 and a third delivery pump 93 may be respectively provided at the outlets of the first energy storage tank 1, the second energy storage tank 3 and the third energy storage tank 2, so as to improve the working efficiency of the energy storage system.

[0154] Optionally, in a specific embodiment, referring to Figure 3 The first heat storage passage and / or the second heat storage passage are provided with a regulating valve.

[0155] Specifically, a fifth regulating valve 85 may be provided in the first heat storage passage, and a sixth regulating valve 86 may be provided in the second heat storage passage. The two regulating valves may respectively control the on-off of the first heat storage passage or the second heat storage passage and the flow rate of the energy storage medium, thereby controlling the heat storage efficiency of the entire energy storage system.

[0156] The utility model also provides a power generation system, which comprises a steam turbine generator set and the above energy storage system, wherein the superheated steam outputted by the above energy storage system in the heat release stage drives the steam turbine generator set to generate electricity.

[0157] In this embodiment, the steam turbine generator set and the energy storage system are combined. At peak times of electricity consumption, the energy storage medium can be used to heat the feed water into superheated steam to drive the steam turbine generator set to generate electricity, thereby playing the role of peak shaving and valley filling and system frequency regulation, providing flexibility for power supply.

[0158] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0159] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0160] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. An energy storage system, characterized in that: At least two energy storage tanks are included for storing energy storage medium, wherein the at least two energy storage tanks include a first energy storage tank and a second energy storage tank, and the temperature of the first energy storage tank is less than or equal to that of the second energy storage tank; A first heat storage passage is provided between the outlet of the first energy storage tank and the inlet of the second energy storage tank, and a first heat exchanger is provided on the first heat storage passage; The energy storage system further includes a waste heat recovery device, wherein a waste heat medium inlet of the waste heat recovery device is connected to a waste heat medium outlet of the first heat exchanger.

2. The energy storage system according to claim 1, characterized in that: The waste heat recovery device includes a heat storage element, and a waste heat medium inlet of the heat storage element is connected to a waste heat medium outlet of the first heat exchanger.

3. The energy storage system according to claim 2, characterized in that: The waste heat recovery device also includes a second heat exchanger, the heat exchange medium inlet of the second heat exchanger is connected to the heat exchange medium outlet of the heat storage element, and the heat exchange medium outlet of the second heat exchanger is connected to the heat exchange medium inlet of the heat storage element to form a circulation loop.

4. The energy storage system according to claim 3, characterized in that: A heat release passage is provided between the outlet of the second energy storage tank and the inlet of the first energy storage tank, a third heat exchanger is provided on the heat release passage, and a water supply inlet of the third heat exchanger is connected to a water supply outlet of the second heat exchanger.

5. The energy storage system according to claim 4, characterized in that: There are at least two heat storage components, and at least two heat storage components are arranged in parallel with each other. The waste heat medium inlet of each heat storage component is connected to the waste heat medium outlet of the first heat exchanger, and the heat exchange medium outlet of each heat storage component is connected to the heat exchange medium inlet of the second heat exchanger. The heat exchange medium inlet of each heat storage component is connected to the heat exchange medium outlet of the second heat exchanger.

6. The energy storage system according to claim 5, characterized in that: A regulating valve is provided at the waste heat medium inlet and / or the heat exchange medium inlet of each heat storage element, and the regulating valve is used to adjust the flow or on-off of the medium in the heat storage passage or the heat release passage in the heat storage element to adjust the working mode of the heat storage element.

7. The energy storage system according to claim 6, characterized in that: The waste heat recovery device also includes a first driving member, the inlet of the first driving member is connected to the heat exchange medium outlet of the second heat exchanger, the outlet of the first driving member is connected to the heat exchange medium inlet of each of the heat storage members, and the first driving member is used to drive the heat exchange medium to circulate.

8. The energy storage system according to any one of claims 1 to 7, characterized in that: The energy storage system further includes a first heater, which is disposed between the first heat exchanger and the second energy storage tank, and a heat storage medium outlet of the first heater is communicated with an inlet of the second energy storage tank.

9. The energy storage system according to claim 8, characterized in that: At least two of the energy storage tanks further include a third energy storage tank for storing energy storage medium, and the temperature of the third energy storage tank is between the temperature of the first energy storage tank and the second energy storage tank; The third energy storage tank and the first heat exchanger are arranged in series on the first heat storage passage, and the inlet of the third energy storage tank is connected to the energy storage medium outlet of the first heat exchanger.

10. The energy storage system according to claim 9, characterized in that: A second heat storage passage is also provided between the outlet of the first energy storage tank and the inlet of the second energy storage tank. The second heat storage passage is provided in parallel with the first heat storage passage. The energy storage medium in the first heat storage passage and the energy storage medium in the second heat storage passage are pre-mixed before entering the first heater.

11. The energy storage system according to claim 9, characterized in that: A third heat storage passage is further provided between the outlet of the first energy storage tank and the inlet of the second energy storage tank, and the third heat storage passage is provided in parallel with the first heat storage passage; The first heater is disposed on the first heat storage passage, and the energy storage medium inlet of the first heater is connected to the outlet of the third energy storage tank; The energy storage system further includes a second heater, which is disposed on the third heat storage path.

12. The energy storage system according to claim 11, characterized in that: There are at least two first heat storage pathways, and the at least two first heat storage pathways are arranged in parallel. The first heat exchanger and the third energy storage tank are arranged in series on each of the first heat storage pathways.

13. The energy storage system according to claim 12, characterized in that: At least two third energy storage tanks with different temperatures are arranged in series on at least one of the first heat storage passages, the first heat exchanger is arranged between the first energy storage tank and the third energy storage tank adjacent to the first energy storage tank, and the first heat exchanger is arranged between two adjacent third energy storage tanks.

14. The energy storage system according to claim 1, characterized in that: The heater used in the energy storage system is an electric heater.

15. The energy storage system according to claim 14, characterized in that: The energy storage system further includes a photovoltaic power station and / or a wind power station, and the photovoltaic power station and / or the wind power station are electrically connected to the electric heater.

16. The energy storage system according to claim 1, characterized in that: The heater used in the energy storage system is a solar collector; The solar thermal collector directly heats the energy storage medium; or, The solar thermal collector indirectly heats the energy storage medium via a heat transfer medium.

17. The energy storage system according to any one of claims 4 to 7, characterized in that: There are at least two third heat exchangers, and at least two third heat exchangers are arranged in series on the heat release passage; The water supply inlet of the third heat exchanger close to the first energy storage tank is communicated with the water supply outlet of the second heat exchanger.

18. The energy storage system according to claim 8, characterized in that: The heat of the waste heat medium comes from industrial waste heat.

19. The energy storage system according to claim 18, characterized in that: It also includes a synthetic ammonia system, and the waste heat medium is the synthesis gas produced by the synthetic ammonia system.

20. The energy storage system according to claim 9, characterized in that: At least one of the first energy storage tank, the second energy storage tank and the third energy storage tank is provided with a heat preservation structure.

21. A power generation system, characterized in that: It comprises a steam turbine generator set and an energy storage system as described in any one of claims 1 to 20, wherein superheated steam outputted during the heat release phase of the energy storage system drives the steam turbine generator set to generate electricity.

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