Combined heat and power generation unit and operation method of combined heat and power generation unit

Abstract

The invention provides a combined heat and power generation unit and an operation method of the combined heat and power generation unit. The invention aims to solve the problem that the residual electricity of the existing unit is difficult to store, reserve heat energy for peak regulation of the unit, and simultaneously cooperate with the cooperation of each unit to ensure the stable operation of the unit, so that the compressor compresses low-temperature low-pressure air into high-temperature high-pressure air by using the residual electricity of the power generation unit, and the high-temperature high-pressure air exchanges heat with low-temperature fused salt through a fused salt heat exchanger of the heat storage unit for heat storage. The combined heat and power generation unit is provided with a power generation unit, a heat storage unit, a heat release unit and an industrial steam supply unit, the heat storage unit comprises a molten salt heat exchanger and further comprises a heat pump circulation unit, the heat pump circulation unit is connected with the heat storage unit, and the heat pump circulation unit comprises a compressor, an expansion machine, a first heat exchanger and a second heat exchanger; the compressor is connected with the fused salt heat exchanger which is connected with the first heat exchanger, the first heat exchanger is connected with the expansion machine, and the expansion machine is connected with the second heat exchanger which is connected with the compressor.

Description

Technical Field

[0001] This application relates to the field of power system technology, and in particular to a combined heat and power (CHP) unit and a method for operating a CHP unit. Background Technology

[0002] As the proportion of renewable energy power generation continues to increase, the power system's demand for flexible adjustment of thermal power units is becoming increasingly urgent. Thermal power units need to adapt to the peak and valley load fluctuations of the power grid, maintain stable operation within a wide load range, and meet the industrial steam supply demand.

[0003] Most existing thermal power units use molten salt heat exchange systems, such as Figure 1 As shown, during periods of low electricity demand, these thermal power units not only fail to efficiently convert excess electrical energy into thermal energy storage, but also operate at low loads. Consequently, parameters such as steam pressure and temperature decrease as output drops, making it difficult for the steam parameters entering industrial steam supply to meet industrial steam demand.

[0004] Therefore, a new type of unit is needed to achieve stable operation during off-peak electricity demand while meeting industrial steam supply needs.

[0005] Application content This application provides a combined heat and power (CHP) unit and a CHP unit operation method. The purpose is to set up a heat pump circulation unit so that during off-peak hours, the compressor uses the surplus electricity from the power generation unit to compress low-temperature, low-pressure air into high-temperature, high-pressure air. The air is then stored by exchanging heat with the low-temperature molten salt in the molten salt heat exchanger of the heat storage unit. This not only solves the problem of storing surplus electricity in existing units, but also provides thermal energy reserves for peak shaving of the unit. At the same time, it coordinates with various units to ensure wide-load operation and stable industrial steam supply.

[0006] To address the aforementioned technical problems, this application provides the following technical solutions: The first aspect of this application provides a combined heat and power (CHP) unit, the CHP unit having a power generation unit and a thermal storage unit, the thermal storage unit including a molten salt heat exchanger, and the CHP unit comprising: A heat pump circulation unit is connected to a heat storage unit. The heat pump circulation unit includes a compressor, an expander, a first heat exchanger, and a second heat exchanger. The heat pump circulation unit is used to convert surplus electricity from the power generation unit into heat energy for storage during off-peak electricity demand. The compressor's working fluid outlet is connected to the working fluid inlet of the molten salt heat exchanger, the molten salt heat exchanger's working fluid outlet is connected to the working fluid inlet of the first heat exchanger, the first heat exchanger's working fluid outlet is connected to the working fluid inlet of the expander, the expander's working fluid outlet is connected to the working fluid inlet of the second heat exchanger, and the second heat exchanger's working fluid outlet is connected to the compressor's working fluid inlet. The compressor is used to compress low-temperature, low-pressure air into high-temperature, high-pressure air using surplus electricity during off-peak hours. After entering the molten salt heat exchanger, the high-temperature, high-pressure air exchanges heat with the low-temperature molten salt from the heat storage unit to transfer heat to the low-temperature molten salt and form high-temperature molten salt. The high-temperature molten salt is then transported to the high-temperature molten salt tank of the heat storage unit for storage.

[0007] A second aspect of this application provides a method for operating a combined heat and power (CHP) unit. The method is applied to a CHP unit, which includes a power generation unit, a thermal storage unit, an industrial steam supply unit, and a heat pump cycle unit. Obtain power consumption status; When the power consumption is at its lowest point, the passage between the heat storage unit, the heat pump cycle unit, and the industrial steam supply unit is opened. The compressor in the heat pump cycle unit is started to use the surplus electricity to compress the low-temperature, low-pressure air into high-temperature, high-pressure air. The high-temperature, high-pressure air enters the molten salt heat exchanger in the heat storage unit to exchange heat with the low-temperature molten salt. The generated high-temperature molten salt is transported to the high-temperature molten salt tank in the heat storage unit for storage. The reheat steam is drawn into the generator unit by the ejector to generate intermediate pressure steam. The intermediate pressure steam is then discharged into the industrial steam supply unit after exchanging heat with low-temperature molten salt in the molten salt heat exchanger of the thermal storage unit.

[0008] A third aspect of this application provides a storage medium comprising a stored program, wherein, when the program is executed, it controls the device containing the storage medium to perform the aforementioned cogeneration unit operation method.

[0009] The fourth aspect of this application discloses an electronic device, the device comprising at least one processor, at least one memory connected to the processor, and a bus; wherein the processor and the memory communicate with each other via the bus; the processor is used to call program instructions in the memory to execute the aforementioned cogeneration unit operation method.

[0010] Compared to existing technologies, this application's combined heat and power (CHP) unit incorporates a heat pump cycle unit during off-peak electricity demand. Firstly, the compressor in the heat pump cycle unit utilizes surplus electricity to compress low-temperature, low-pressure air into high-temperature, high-pressure air. Then, the heat is transferred to low-temperature molten salt via a molten salt heat exchanger, forming high-temperature molten salt storage. This achieves efficient conversion and storage of surplus electricity into thermal energy, completely solving the problem of surplus electricity utilization in existing units. Secondly, the linkage between the first and second heat exchangers in the heat pump cycle and the industrial steam supply unit optimizes steam parameters through the heat exchange process, compensating for the insufficient steam parameters in existing units and ensuring that industrial steam demand is met. This solution not only achieves the conversion of surplus electrical energy but also ensures the stability of industrial steam supply, maintaining the stable operation of the CHP unit. Attached Figure Description

[0011] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of this application are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein: Figure 1 The diagram schematically illustrates a steam and power supply system for a thermal power unit in the prior art; Figure 2 A combined heat and power (CHP) unit is schematically shown. Figure 3 This schematically illustrates a method for operating a combined heat and power (CHP) unit.

[0012] Explanation of icon numbers: 1. Boiler; 2. High-pressure cylinder; 3. Medium-pressure cylinder; 4. Low-pressure cylinder; 5. Generator; 6. Condenser; 7. Condensate pump; 8. Low-pressure heater; 9. Deaerator; 10. Water pump; 11. High-pressure heater; 12. First valve; 13. Second valve; 14. Ejector; 15. Third valve; 16. Fourth valve; 17. First molten salt heat exchanger; 18. Second molten salt heat exchanger; 19. Molten salt heat exchanger; 20. High-temperature molten salt tank; 21. Low-temperature molten salt tank; 22. Fifth valve; 23. Low-temperature molten salt pump; 24. Sixth valve; 25. High-temperature molten salt pump; 26. Fourth molten salt heat exchanger; 27. Compressor; 28. First heat exchanger; 29. ​​Expander; 30. Second heat exchanger. Detailed Implementation

[0013] Exemplary embodiments of this application will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of this application are shown in the drawings, it should be understood that this application may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this application and to fully convey the scope of this application to those skilled in the art.

[0014] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains.

[0015] With the continuous increase in the proportion of renewable energy power generation, the demand for flexible regulation of thermal power units in the power system is becoming increasingly urgent. Thermal power units need to adapt to peak and valley load fluctuations in the power grid, maintain stable operation over a wide load range, and meet industrial steam supply needs. Most existing thermal power units use molten salt heat exchange systems, such as... Figure 1 As shown, during periods of low electricity demand, the excess electrical energy of this type of thermal power unit cannot be efficiently converted into thermal energy for storage. The unit's low-load operating efficiency drops significantly, and the reheat steam parameters are insufficient to meet industrial steam supply demands.

[0016] To address this, the applicant provides a combined heat and power (CHP) unit to solve the technical problems in the prior art. Specifically, the CHP unit includes a power generation unit, a heat storage unit, a heat release unit, and an industrial steam supply unit. The heat storage unit includes a molten salt heat exchanger and a heat pump circulation unit connected to the heat storage voltage. The heat pump circulation unit includes a compressor, an expander, a first heat exchanger, and a second heat exchanger. The heat pump circulation unit is used to convert surplus electricity from the power generation unit into heat energy for storage during off-peak hours and to use the stored heat energy for peak shaving of the unit. The compressor's working fluid outlet is connected to the working fluid inlet of the molten salt heat exchanger, the molten salt heat exchanger's working fluid outlet is connected to the working fluid inlet of the first heat exchanger, the first heat exchanger's working fluid outlet is connected to the working fluid inlet of the expander, the expander's working fluid outlet is connected to the working fluid inlet of the second heat exchanger, and the second heat exchanger's working fluid outlet is connected to the compressor's working fluid inlet. The compressor is used to compress low-temperature, low-pressure air into high-temperature, high-pressure air using surplus electricity during off-peak hours. After entering the molten salt heat exchanger, the high-temperature, high-pressure air exchanges heat with the low-temperature molten salt from the heat storage unit to transfer heat to the low-temperature molten salt and form high-temperature molten salt. The high-temperature molten salt is then transported to the high-temperature molten salt tank of the heat storage unit for storage.

[0017] The combined heat and power unit further includes: the heat pump circulation unit connected to the heat storage unit, the heat storage unit connected to the heat release unit, the heat storage unit connected to the industrial steam supply unit, the heat release unit connected to the industrial steam supply unit, the industrial steam supply unit connected to the power generation unit, and the power generation unit connected to the heat storage unit.

[0018] The power generation unit in a combined heat and power (CHP) unit includes a boiler, a steam turbine, a condenser, a low-pressure heater, a deaerator, and a high-pressure heater. The steam turbine unit includes a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder. It uses the steam generated in the boiler to do work and coaxially drives the generator to generate electricity. The condenser is used to cool the steam discharged from the low-pressure cylinder into condensate and input the condensate into the low-pressure heater; the low-pressure heater is used to heat the condensate in the low-pressure heater using steam drawn from the low-pressure cylinder; the deaerator is used to heat the feedwater from the low-pressure heater using steam drawn from the intermediate-pressure cylinder; the high-pressure heater is used to heat the feedwater from the deaerator outlet pump using steam drawn from the high-pressure cylinder.

[0019] The combined heat and power (CHP) units also include: The main steam transmission from the boiler outlet of the power generation unit has two paths, including a first path and a second path, comprising: The first path is for the main steam from the boiler outlet to enter the high-pressure cylinder of the turbine unit, and the steam thermal energy is converted into mechanical energy by the expansion and work process of the high-pressure cylinder to provide power for the generator to generate electricity. The second path is for the main steam from the boiler outlet to be transported to the ejector through the first valve. The reheat steam generated by the boiler is transported in three ways. The first way is to transport the reheat steam to the ejector through the second valve. The reheat steam is used as the ejector fluid of the ejector and works with the active fluid to generate intermediate pressure steam. The second way is to transport the reheat steam to the second molten salt heat exchanger of the heat storage unit through the third valve. The heat is transferred to the low temperature molten salt through the heat exchange process to achieve thermal energy storage. The third way is to transport the reheat steam directly into the intermediate pressure cylinder of the steam turbine to do work. The steam after doing work enters the low pressure cylinder to complete expansion and do work. The heat release unit has a fourth valve, which is located between the deaerator and the fourth molten salt heat exchanger.

[0020] The combined heat and power unit also includes: the heat storage unit includes a high-temperature molten salt tank, a low-temperature molten salt tank, a high-temperature molten salt pump, a low-temperature molten salt pump, a first molten salt heat exchanger, a second molten salt heat exchanger, a molten salt heat exchanger, and a fourth molten salt heat exchanger. The molten salt inlet of the high-temperature molten salt tank is connected to the first molten salt heat exchanger, the second molten salt heat exchanger, and the medium outlet of the molten salt heat exchanger. The molten salt outlet of the high-temperature molten salt tank is connected to the medium inlet of the fourth molten salt heat exchanger, forming a first molten salt circulation loop. The molten salt circulation loop is used to receive and store the high-temperature molten salt generated after heat exchange in the first molten salt heat exchanger, the second molten salt heat exchanger, and the molten salt heat exchanger, and to transport the high-temperature molten salt to the fourth molten salt heat exchanger when heat release is required. The molten salt outlet of the cryogenic molten salt tank is connected to the first molten salt heat exchanger, the second molten salt heat exchanger, and the medium inlet of the molten salt heat exchanger; the molten salt inlet of the cryogenic molten salt tank is connected to the medium outlet of the fourth molten salt heat exchanger, forming a second molten salt circulation loop. The second molten salt circulation loop is used to provide cryogenic molten salt to the first molten salt heat exchanger, the second molten salt heat exchanger, and the molten salt heat exchanger, and to receive cryogenic molten salt formed by the fourth molten salt heat exchanger after heat release and cooling. A sixth valve is provided between the high-temperature molten salt tank and the fourth molten salt heat exchanger, and a fifth valve is provided between the low-temperature molten salt tank and the junction of the conveying pipelines of the first molten salt heat exchanger, the second molten salt heat exchanger, and the molten salt heat exchanger. The fifth valve is used to control the opening and closing of the conveying path of high-temperature molten salt to the fourth molten salt heat exchanger and the conveying path of low-temperature molten salt to the first molten salt heat exchanger, the second molten salt heat exchanger, and the molten salt heat exchanger, respectively. The high-temperature molten salt pump is installed on the molten salt conveying pipeline between the high-temperature molten salt tank and the fourth molten salt heat exchanger, and is used to provide power for the flow of high-temperature molten salt from the high-temperature molten salt tank to the fourth molten salt heat exchanger. The cryogenic molten salt pump is installed on the molten salt delivery pipeline between the cryogenic molten salt tank and the first molten salt heat exchanger, the second molten salt heat exchanger, and the molten salt heat exchanger, and is used to provide power for the flow of cryogenic molten salt from the cryogenic molten salt tank to each molten salt heat exchanger.

[0021] Specifically, such as Figure 2 As shown, the combined heat and power unit not only has a power generation unit, a heat storage unit, a heat release unit, and an industrial steam supply unit, but also includes a molten salt heat exchanger 19 and a heat pump cycle unit. The heat pump cycle unit includes a compressor 27, an expander 19, a first heat exchanger 28, and a second heat exchanger 30. The heat pump cycle unit is used to convert surplus electricity into heat energy for storage during off-peak hours and to use the stored heat energy for peak shaving of the unit. The compressor 27 has its working fluid outlet connected to the working fluid inlet of the molten salt heat exchanger 19. The working fluid outlet of the molten salt heat exchanger 19 is connected to the working fluid inlet of the first heat exchanger 28. The working fluid outlet of the first heat exchanger 28 is connected to the working fluid inlet of the expander 29. The working fluid outlet of the expander 29 is connected to the working fluid inlet of the second heat exchanger 30. The working fluid outlet of the second heat exchanger 30 is connected to the working fluid inlet of the compressor 27. The compressor 27 is used to compress low-temperature, low-pressure air into high-temperature, high-pressure air using surplus electricity during off-peak hours. This high-temperature, high-pressure air enters the molten salt heat exchanger and exchanges heat with the low-temperature molten salt from the heat storage unit, transferring heat to the low-temperature molten salt and forming high-temperature molten salt. The high-temperature molten salt is then transported to the high-temperature molten salt tank of the heat storage unit for storage. The surplus electricity is the difference between the electricity generated by the generator set and the electricity generated during off-peak hours.

[0022] The combined heat and power unit further includes: the heat pump circulation unit connected to the heat storage unit, the heat storage unit connected to the heat release unit, the heat storage unit connected to the industrial steam supply unit, the heat release unit connected to the industrial steam supply unit, the industrial steam supply unit connected to the power generation unit, and the power generation unit connected to the heat storage unit.

[0023] The power generation unit in the cogeneration unit includes a boiler 1, a steam turbine unit, a condenser 6, a low-pressure heater 8, a deaerator 9, and a high-pressure heater 11.

[0024] The steam turbine unit includes a high-pressure cylinder 2, an intermediate-pressure cylinder 3, and a low-pressure cylinder 4. It uses the steam generated in the boiler 1 to do work and coaxially drives the generator to generate electricity.

[0025] The condenser 6 is used to cool the steam discharged from the low-pressure cylinder 4 into condensate and input the condensate into the low-pressure heater 8; the low-pressure heater 8 is used to heat the condensate in the low-pressure heater 8 using the steam drawn from the low-pressure cylinder 4; the deaerator 9 is used to heat the feedwater from the low-pressure heater 8 using the steam drawn from the intermediate-pressure cylinder; the high-pressure heater 11 is used to heat the feedwater from the deaerator outlet water pump using the steam drawn from the high-pressure cylinder 2.

[0026] The combined heat and power (CHP) units also include: The main steam transmission at the boiler 1 outlet of the power generation unit has two paths, including a first path and a second path, comprising: The first path is for the main steam from the boiler outlet to enter the high-pressure cylinder 2 of the turbine unit, and the expansion of the high-pressure cylinder 2 is used to convert the steam thermal energy into mechanical energy to provide power for the generator to generate electricity. The second path is for the main steam from the boiler outlet to be transported to the ejector 14 through the first valve 12.

[0027] The reheat steam generated by the boiler is transported in three ways. The first way is to transport the reheat steam to the ejector 14 via the second valve 13. The reheat steam is used as the ejector fluid of the ejector 14 and works together with the active fluid to generate intermediate pressure steam. The second way is to transport the reheat steam to the second molten salt heat exchanger 18 of the heat storage unit via the third valve 15. The heat is transferred to the low temperature molten salt through the heat exchange process to achieve thermal energy storage. The third way is to transport the reheat steam directly into the intermediate pressure cylinder 3 of the turbine unit to do work. The steam after doing work enters the low pressure cylinder 4 to complete expansion and do work.

[0028] The heat release unit has a fourth valve 16, which is located between the deaerator 9 and the fourth molten salt heat exchanger 26.

[0029] The combined heat and power unit also includes: the heat storage unit includes a high-temperature molten salt tank 20, a low-temperature molten salt tank 21, a high-temperature molten salt pump 25, a low-temperature molten salt pump 23, a first molten salt heat exchanger 17, a second molten salt heat exchanger 18, a molten salt heat exchanger 19, and a fourth molten salt heat exchanger 26. The molten salt inlet of the high-temperature molten salt tank 20 is connected to the medium outlet of the first molten salt heat exchanger 17, the second molten salt heat exchanger 18, and the molten salt heat exchanger 19. The molten salt outlet of the high-temperature molten salt tank 20 is connected to the medium inlet of the fourth molten salt heat exchanger 26, forming a first molten salt circulation loop. The molten salt circulation loop is used to receive and store the high-temperature molten salt generated after heat exchange in the first molten salt heat exchanger 17, the second molten salt heat exchanger 18, and the molten salt heat exchanger 19, and to transport the high-temperature molten salt to the fourth molten salt heat exchanger 26 when heat release is required.

[0030] The molten salt outlet of the low-temperature molten salt tank 21 is connected to the medium inlet of the first molten salt heat exchanger 17, the second molten salt heat exchanger 18, and the molten salt heat exchanger 19; the molten salt inlet of the low-temperature molten salt tank 21 is connected to the medium outlet of the fourth molten salt heat exchanger 26, forming a second molten salt circulation loop. The second molten salt circulation loop is used to provide low-temperature molten salt to the first molten salt heat exchanger 17, the second molten salt heat exchanger 18, and the molten salt heat exchanger 19, and to receive low-temperature molten salt formed by the cooling of the fourth molten salt heat exchanger 16 after heat release. A sixth valve 24 is provided between the high-temperature molten salt tank 20 and the fourth molten salt heat exchanger 26. A fifth valve 22 is provided between the low-temperature molten salt tank 21 and the junction of the conveying pipelines of the first molten salt heat exchanger 17, the second molten salt heat exchanger 18, and the molten salt heat exchanger 19. The fifth valve 22 is used to control the opening and closing of the conveying path of high-temperature molten salt to the fourth molten salt heat exchanger 26 and the conveying path of low-temperature molten salt to the first molten salt heat exchanger 17, the second molten salt heat exchanger 18, and the molten salt heat exchanger 19, respectively. The high-temperature molten salt pump 25 is installed on the molten salt conveying pipeline between the high-temperature molten salt tank 20 and the fourth molten salt heat exchanger 26, and is used to provide power for the flow of high-temperature molten salt from the high-temperature molten salt tank 20 to the fourth molten salt heat exchanger 26. The cryogenic molten salt pump 23 is installed on the molten salt conveying pipeline between the cryogenic molten salt tank 21 and the first molten salt heat exchanger 17, the second molten salt heat exchanger 18, and the molten salt heat exchanger 19, and is used to provide power for the flow of cryogenic molten salt from the cryogenic molten salt tank to each molten salt heat exchanger.

[0031] Furthermore, the applicant provides a detailed discussion of the aforementioned combined heat and power (CHP) units, as follows: Among them, the heat pump cycle unit is connected to the heat storage unit. Under low load, low temperature and low pressure air is electrically compressed by the compressor to form high temperature and high pressure air. After exchanging heat with molten salt, it enters the expander to do work. Finally, after exchanging heat with the environment, it returns to the compressor. The power generation unit includes a generator, and the high-pressure cylinder, medium-pressure cylinder, and low-pressure cylinder are located on the same main shaft as the generator to drive the generator to generate electricity. The heat storage unit is connected to the heat release unit, the heat pump cycle unit, and the industrial steam supply unit, and stores the heat of the high-grade steam of the unit and the heat generated by the heat pump cycle unit in a high-temperature molten salt tank respectively. The heat release unit is connected to the heat storage unit and the industrial steam supply unit to heat the deaerator feedwater. The deaerator feedwater is then discharged into the steam supply header after being heated by high-temperature molten salt.

[0032] The industrial steam supply system is connected to the boiler, turbine unit, and heat release unit. During the heat storage process, at medium to high loads, reheat steam is directly extracted for industrial steam supply, and the superheat of the industrial steam is stored in a high-temperature molten salt tank. When the load is extremely low, the reheat steam cannot meet the industrial steam supply requirements. Reheat steam is drawn from the main steam to obtain intermediate pressure steam, which then enters the molten salt heat exchanger to exchange heat with the molten salt before being discharged into the steam supply header for steam supply. At the same time, during the heat release process, the deaerator feedwater is heated by high-temperature molten salt and then discharged into the steam supply header to supply steam to industrial steam users.

[0033] Specifically, in this embodiment, the intermediate pressure steam of the turbine unit and the high-temperature and high-pressure air working fluid in the Carnot battery system are used as the heat source of the heat exchange system, so that the turbine unit and the power generation unit consume less high-grade energy of the thermal power generator unit, and the unit output can be reduced when needed, while meeting the peak demand of the unit.

[0034] Furthermore, the heat pump cycle unit includes: the working fluid outlet of the compressor 27 is connected to the working fluid inlet of the second molten salt heat exchanger 18, and the compressor 27 compresses low-temperature, low-pressure air electrically to form high-temperature, high-pressure air; the working fluid inlet of the expander 29 is connected to the working fluid outlet of the first heat exchanger 28, and the air after heat exchange enters the expander 29 to do work, and after exchanging heat with the environment through the second heat exchanger 30, it returns to the compressor 27.

[0035] Furthermore, the power generation unit includes: Boiler 1 burns coal to produce high-temperature, high-pressure main steam.

[0036] The steam turbine unit includes a high-pressure cylinder 2, an intermediate-pressure cylinder 3, and a low-pressure cylinder 4. It uses the steam generated in the boiler 1 to do work and coaxially drives the generator 5 to generate electricity.

[0037] Condenser 6 cools the exhaust steam from low-pressure cylinder 4 into condensate, which then enters low-pressure heater 8; Low-pressure heater 8, steam is drawn from the low-pressure cylinder 4 and enters the low-pressure heater 8 to heat the condensate; Steam is drawn from the medium-pressure cylinder 3 into the deaerator 9 to reheat the feedwater from the low-pressure heater 8; High-pressure heater 11, steam drawn from high-pressure cylinder 2 enters high-pressure heater 11 to heat feedwater from deaerator outlet water pump 10.

[0038] Furthermore, the power generation unit also includes: The main steam at the outlet of boiler 1 is divided into two paths. One path enters the high-pressure cylinder 2 to do work, and the other path enters the ejector 14 through the first valve 12 as the active fluid. Part of the reheat steam of boiler 1 enters the ejector 14 through the second valve 13 as the ejector fluid, part of the reheat steam enters the molten salt heat exchanger II through the third valve 15 to heat the molten salt, and another part of the reheat steam enters the intermediate-pressure cylinder 3 to do work and then enters the low-pressure cylinder 4 to do work. The exhaust steam from the low-pressure cylinder 4 enters the condenser 6 to be cooled into saturated water. After being pressurized by the water pump 7, it is heated by the low-pressure heater 8, the deaerator 9, and the high-pressure heater 11 and then returned to boiler 1.

[0039] Furthermore, the thermal storage unit includes: The high-temperature molten salt tank 20 is used to store high-temperature molten salt. The molten salt inlet of the high-temperature molten salt tank 20 is connected to the medium outlet of the first molten salt heat exchanger 17, the second molten salt heat exchanger 18 and the molten salt heat exchanger 9. The molten salt outlet of the high-temperature molten salt tank 22 is connected to the medium inlet of the fourth molten salt heat exchanger 26. The cryogenic molten salt tank 21 is used to store cryogenic molten salt. The molten salt outlet of the cryogenic molten salt tank 21 is connected to the medium inlet of the first molten salt heat exchanger 17, the second molten salt heat exchanger 18 and the molten salt heat exchanger 19. The molten salt inlet of the cryogenic molten salt tank 21 is connected to the medium outlet of the fourth molten salt heat exchanger 26. A sixth valve 24 is provided between the high-temperature molten salt tank 20 and the fourth molten salt heat exchanger 26; a fifth valve 22 is provided between the low-temperature molten salt tank 21 and the first molten salt heat exchanger 17, the second molten salt heat exchanger 18 and the molten salt heat exchanger 19. Furthermore, the thermal storage unit also includes: A high-temperature molten salt pump 25 is installed at the molten salt outlet end of the high-temperature molten salt tank 20; a low-temperature molten salt pump 23 is installed at the molten salt outlet end of the low-temperature molten salt tank 21. The high-temperature molten salt pump 25 and the low-temperature molten salt pump 23 promote the normal flow of molten salt, thereby ensuring the heat exchange effect.

[0040] Furthermore, the heat release unit includes: A fourth valve 16 is provided at the inlet section of the deaerator 9 and the fourth molten salt heat exchanger 26; The feedwater from deaerator 9 enters the fourth molten salt heat exchanger 26 via the fourth valve 16 to exchange heat with the high-temperature molten salt before being discharged into the steam supply header to supply steam to industrial steam users.

[0041] Furthermore, the industrial steam supply unit includes: A first valve 12 is installed between the ejector 14 and the main steam pipe; A second valve 13 is installed between the ejector 14 and the hot resteam pipeline; The ejector 14 uses part of the main steam as a high-pressure driving heat source to extract part of the hot reheat steam to obtain intermediate pressure steam. The intermediate pressure steam enters the first molten salt heat exchanger 17 for heat exchange, and after heat exchange, it is discharged into the steam supply header to supply steam to industrial steam users.

[0042] Specifically, a portion of the main steam enters the ejector 14 through the first valve 12 as the active fluid, and a portion of the hot resteam enters the ejector 14 through the second valve 13 as the ejector fluid.

[0043] Based on this, the aforementioned units, through multi-unit collaborative design and precise configuration of key components, have achieved multiple core technological effects: Firstly, the power support of the high-temperature molten salt pump 25 and the low-temperature molten salt pump 23 ensures efficient circulation of molten salt between heat exchangers and molten salt tanks, guaranteeing a stable and sufficient heat exchange process and avoiding energy storage efficiency degradation due to poor molten salt flow. Secondly, through deep coupling of the heat pump circulation unit and the Carnot battery system, surplus electricity at low loads is efficiently converted into high-temperature thermal energy storage. Simultaneously, the innovative design of using main steam to extract reheat steam to generate intermediate-pressure steam solves the pain point of insufficient reheat steam parameters at extremely low loads, ensuring stable industrial steam supply pressure and temperature (fluctuation < ±3%). Thirdly, the multi-path steam transmission and heater collaborative heat exchange mechanism of the power generation unit, combined with the precise control of the dual molten salt tanks and multiple valves in the thermal storage unit, achieves a THA range from -23% to 100%. Its wide-range flexible operation not only enhances the deep peak-shaving capability of thermal power units, but also releases stored heat energy to meet steam supply demand during peak electricity demand through dynamic adaptation of heat storage and release processes, avoiding mutual constraints between power generation and steam supply. The industrial steam supply system directly extracts reheat steam and stores superheat during medium and high loads, and supplements energy through molten salt heat exchange during extremely low loads, ensuring the quality of steam supply throughout the process. At the same time, it significantly reduces efficiency losses and equipment lifespan degradation during low-load operation of the units, ultimately achieving multiple goals of high-efficiency energy storage, flexible peak-shaving, and stable steam supply, perfectly adapting to the peak and valley load fluctuations of a high-proportion renewable energy grid.

[0044] Furthermore, this application also provides a method for operating a combined heat and power unit, specifically as follows: Figure 3 As shown: Step 301: Obtain power consumption status.

[0045] In this embodiment, the method for obtaining the power consumption status is a method of determining the power consumption status by linking dispatch instructions with load thresholds.

[0046] Based on the peak-shaving instructions issued by the power grid dispatch platform, and combined with the real-time load threshold of the power grid, the power consumption status is determined. First, the unit data receiving module receives the power consumption period identifiers (such as "valley thermal storage" and "peak peak" instructions) and corresponding load adjustment requirements issued by the dispatch center in real time through the dedicated power grid dispatch link. Second, it synchronously collects the real-time load rate data of the power grid and compares it with the load threshold range preset by the project. When the dispatch instruction is "valley thermal storage" and the power grid load rate is less than the first preset load, it is determined to be a low-valley power consumption. When the dispatch instruction has no special requirements and the power grid load rate is within the range determined by the first preset load and the second preset load, it is determined to be normal power consumption. When the dispatch instruction is "peak peak" or the power grid load rate is greater than the second preset load, it is determined to be a peak power consumption. Simultaneously, a secondary verification is performed by combining the basic demand data of industrial steam supply (such as minimum steam supply). If a sudden increase in industrial steam supply demand requires the unit to maintain a high output, the judgment result can be fine-tuned (such as delaying the switching to off-peak mode), ensuring that the power consumption status judgment not only meets the grid dispatch requirements but also adapts to the actual operating conditions of the unit. Through the above steps, the traditional single judgment mode that relies solely on grid load is broken. Dynamic and accurate identification of power consumption status is achieved through multi-dimensional data coupling, avoiding misjudgments caused by fluctuations in new energy output or changes in industrial steam supply demand. At the same time, it provides advance notice for the coordinated operation of various units of the unit (heat pump, thermal storage, steam supply), ensuring the timeliness and accuracy of the unit's response to grid peak-shaving demand, and solving the problem of energy storage and steam supply imbalance caused by the lag in status judgment in existing technologies.

[0047] Step 302: When the power consumption status is at a low power consumption period, the passage between the heat storage unit, the heat pump circulation unit, and the industrial steam supply unit is opened. The compressor in the heat pump circulation unit is started to use the surplus electricity to compress the low-temperature, low-pressure air into high-temperature, high-pressure air. The high-temperature, high-pressure air enters the molten salt heat exchanger in the heat storage unit to exchange heat with the low-temperature molten salt. The generated high-temperature molten salt is transported to the high-temperature molten salt tank in the heat storage unit for storage.

[0048] When it is determined that it is a low electricity consumption period, the unit control system triggers the following linkage actions: First, connect the heat storage unit and the heat pump cycle unit, open the fifth valve at the outlet of the low-temperature molten salt tank and the low-temperature molten salt pump, and transport the low-temperature molten salt to the molten salt heat exchanger; Second, start the compressor of the heat pump cycle unit, and use the surplus electric energy of the power generation unit and the abandoned electricity from the power grid to compress the low-temperature and low-pressure air in the environment to a high-temperature and high-pressure state; Subsequently, the high-temperature and high-pressure air is introduced into the molten salt heat exchanger to exchange heat with the low-temperature molten salt. After the air releases heat, its temperature drops, and the low-temperature molten salt absorbs heat and rises in temperature to form high-temperature molten salt; Finally, the high-temperature molten salt is transported to the high-temperature molten salt tank for sealed storage through the molten salt pipeline, and at the same time, the redundant passages between the heat pump cycle unit and other units are closed to ensure no heat loss. In this step, the heat pump cycle of the Carnot battery is deeply coupled with molten salt heat storage to achieve the efficient conversion of surplus electricity into high-grade heat energy, solving the problems of inefficient storage of surplus electricity and low operating efficiency at low loads in the prior art; at the same time, the sealed storage of high-temperature molten salt avoids heat energy loss, reserves a stable heat source for peak shaving during subsequent high electricity consumption periods, enables the unit to maintain a high energy utilization efficiency under low load conditions, and reduces the attenuation of equipment life caused by frequent peak shaving.

[0049] Step 302: Use the ejector of the power generation unit to extract and reheat steam to generate intermediate pressure steam. After the intermediate pressure steam exchanges heat with the low-temperature molten salt in the molten salt heat exchanger of the heat storage unit, it is discharged into the industrial steam supply unit.

[0050] While step 302 is being executed, to ensure industrial steam supply demand, the unit control system starts the linkage between the power generation unit and the industrial steam supply unit: First, connect the passage between the power generation unit and the ejector, open the first valve of the boiler main steam pipeline and the second valve of the reheated steam pipeline, and make the main steam (as the driving fluid and the reheated steam as the ejecting fluid) enter the ejector together; Second, through the Venturi effect of the ejector, mix the two kinds of steam and adjust them to intermediate pressure steam that meets the industrial steam supply parameters; Subsequently, the intermediate pressure steam is introduced into the first molten salt heat exchanger of the heat storage unit to exchange heat with the low-temperature molten salt for the second time. After the steam releases heat, its temperature is maintained at a level that meets the industrial steam temperature requirements, and the low-temperature molten salt further absorbs heat and rises in temperature to become high-temperature molten salt; Finally, the heat-exchanged steam is transported to industrial users through the steam supply header pipe, and at the same time, the high-temperature molten salt generated by the secondary heat exchange is transported to the high-temperature molten salt tank for storage. The ejector technology creatively solves the problem of insufficient reheated steam parameters during low electricity consumption periods, realizes the parameter matching and efficient utilization of the main steam and the reheated steam, and ensures the stability of the pressure and temperature of the industrial steam supply (the fluctuation range < ±3%); at the same time, the waste heat of the steam is used to heat the molten salt for the second time, achieving the dual goals of "steam supply + energy storage", avoiding the drawback of sacrificing the peak shaving ability of the unit to ensure steam supply in the prior art, enabling the unit to meet the industrial steam supply demand during low electricity consumption periods and complete energy storage at the same time, and improving the overall operation flexibility. [[ID=?]] [[ID=?]]

[0051] Furthermore, when the power consumption is at its peak, after connecting the heat exchange path between the heat storage unit and the heat release unit and closing the linkage path between the heat storage unit and the heat pump circulation unit, the high-temperature molten salt pump in the heat storage unit is started. The high-temperature molten salt stored in the high-temperature molten salt tank is transported to the fourth molten salt heat exchanger associated with the heat release unit by the high-temperature molten salt pump. The fourth molten salt heat exchanger is then used to exchange heat with the deaerator feedwater of the power generation unit. After the deaerator feedwater reaches the preset steam supply parameters after heat exchange, it is discharged into the industrial steam supply unit.

[0052] Specifically, when the unit control system determines that it is peak electricity demand, it first connects the heat exchange path between the thermal storage unit and the heat release unit through valve linkage control: the sixth valve at the outlet of the high-temperature molten salt tank is opened, and the fifth, first, second, and third valves and redundant passages connecting the thermal storage unit and the heat pump circulation unit are closed to cut off the heat pump circulation and avoid energy loss; then the high-temperature molten salt pump in the thermal storage unit is started to deliver the high-temperature molten salt stored in the high-temperature molten salt tank to the associated heat release unit at a preset flow rate (adjusted according to industrial steam supply demand). The fourth molten salt heat exchanger is connected; simultaneously, the passage between the deaerator and the fourth molten salt heat exchanger is opened, and the fourth valve is opened to allow the feedwater from the deaerator outlet to enter the fourth molten salt heat exchanger for countercurrent heat exchange with the high-temperature molten salt; the flow ratio of molten salt to feedwater is adjusted in real time through the temperature monitoring module to ensure that the feedwater reaches the preset steam supply parameters (temperature 360-380℃, pressure 1.2-1.5MPa) after heat exchange, and finally the qualified high-temperature feedwater is discharged into the industrial steam supply unit through the steam supply header to meet the steam demand of industrial users during peak electricity consumption. It is evident that the above methods utilize high-temperature molten salt stored during off-peak electricity demand as a heat source, replacing the traditional steam extraction method. This avoids power generation losses caused by extracting steam from the power generation unit during peak electricity demand, achieving dynamic decoupling between power generation and steam supply. The high-efficiency heat exchange between the high-temperature molten salt and the deaerator feedwater (heat exchange efficiency exceeding 90%) ensures stable industrial steam supply parameters (fluctuation < ±3%), solving the problem of steam pressure fluctuations during peak demand in existing technologies. Simultaneously, the released heat energy directly serves the steam supply demand without the need for secondary energy conversion, improving energy utilization efficiency. This helps the unit meet industrial steam supply needs while ensuring full-load peak operation of the power generation unit, enhancing the grid's ability to cope with peak loads.

[0053] Furthermore, when the power consumption is normal, the connection valve between the thermal storage unit and the industrial steam supply unit is switched, allowing the industrial steam supply unit to directly draw reheat steam from the power generation unit; the molten salt heat exchanger passage in the thermal storage unit, used to absorb the superheat of the steam, is opened, so that the reheat steam transfers its superheat to the low-temperature molten salt in the thermal storage unit during the steam supply process; after the low-temperature molten salt absorbs heat and transforms into high-temperature molten salt, it is transported to the high-temperature molten salt tank for storage through the transport pipeline of the thermal storage unit, completing the thermal energy reserve, and at the same time controlling the turbine unit of the power generation unit to maintain operation within the rated load range, and ensuring the stability of the thermal cycle of the power generation unit through the coordinated heat exchange of the low-pressure heater, deaerator, and high-pressure heater.

[0054] Specifically, when normal power consumption is detected, the unit control system first switches valves: closing the pathways between the thermal storage unit and the heat pump circulation unit and the heat release unit, and opening the connection valves between the thermal storage unit and the industrial steam supply unit (opening the third and fifth valves, and closing the first, second, fourth, and sixth valves), allowing the industrial steam supply unit to directly extract reheat steam (temperature 540-560℃, pressure 3.5-4.0MPa) before the inlet of the intermediate pressure cylinder in the power generation unit; simultaneously, the second molten salt heat exchanger in the thermal storage unit is opened. The system initiates the process of starting the cryogenic molten salt pump to transport the cryogenic molten salt in the cryogenic molten salt tank to the second molten salt heat exchanger. During the reheat steam delivery to industrial users, it first enters the second molten salt heat exchanger, transferring its superheat (the portion exceeding the industrial steam supply temperature) to the cryogenic molten salt. Once the steam temperature drops to (meeting industrial steam supply parameters), it is delivered to users through the steam supply header. The cryogenic molten salt, having absorbed heat, heats up to form high-temperature molten salt, which is then transported through pipelines to the high-temperature molten salt tank for storage. Simultaneously, the system controls the turbine generator unit to operate at 80%-100% of its rated load, ensuring stable feedwater temperature and maintaining a balanced power generation thermal cycle through coordinated heat exchange via low-pressure heaters, deaerators, and high-pressure heaters according to preset parameters. In this scenario, without the need for additional electricity consumption or sacrifice of power generation output, the superheat of reheated steam achieves the dual goals of "steam supply + energy storage," thereby improving the overall energy utilization rate. The reheated steam releases heat before being supplied, ensuring stable industrial steam supply parameters (temperature fluctuation < ±2%) and resolving the steam quality issues caused by the superheat of steam in traditional direct steam supply. The power generation unit maintains rated load operation, avoiding low-load efficiency losses, while ensuring stable thermal circulation through coordinated heat exchange with heaters. This balances grid power supply needs with industrial steam supply reliability, achieving economical and stable unit operation.

[0055] Furthermore, the applicant of this application provides specific methodological examples, to... Figure 2 Taking a combined heat and power (CHP) unit as an example, the details are as follows: During normal power supply: The third valve 15 and the fifth valve 22 are opened, while the first valve 12, the second valve 13, the fourth valve 16, and the sixth valve 24 are closed. Reheat steam is extracted and used as industrial steam, supplied to industrial users. Simultaneously, the superheat of the industrial steam is stored in the high-temperature molten salt tank 20 through the second molten salt heat exchanger 18. Specifically, during high-load operation of the unit, reheat steam is extracted and used as industrial steam, and the superheat of the industrial steam is stored in the high-temperature molten salt tank through the second molten salt heat exchanger 18.

[0056] During periods of low electricity demand: First valve 12, second valve 13, third valve 15, and fifth valve 22 are opened, while fourth valve 16 and sixth valve 24 are closed. Since reheat steam cannot meet industrial steam demand, in addition to extracting reheat steam for industrial supply, intermediate pressure steam is generated by drawing reheat steam from the main steam source. This intermediate pressure steam enters the first molten salt heat exchanger 17 to heat the low-temperature molten salt and is stored in the high-temperature molten salt tank 20. The heated steam is then discharged into the main steam supply pipe. Simultaneously, excess electrical energy is used to drive the compressor 27. The high-temperature, high-pressure air, electrically compressed by the compressor 27, enters the molten salt heat exchanger 19 to exchange heat with the low-temperature molten salt. Subsequently, after the expander 29 performs work, it exchanges heat with the environment in the second heat exchanger 30, ultimately forming low-temperature, low-pressure air that re-enters the compressor 27, completing one cycle.

[0057] Specifically, when the unit is operating at low load, the first, second, third, and fifth valves are opened, and the cryogenic molten salt pump is started, allowing the cryogenic molten salt to enter the first, second, and third molten salt heat exchangers for heat exchange. The intermediate pressure steam and reheat steam heat the cryogenic molten salt in the first and second molten salt heat exchangers, respectively. The steam after heat release is discharged into the steam supply header to supply steam to industrial steam users. The electric motor, powered by the generator and the surplus of renewable energy, drives the compressor. The compressor compresses the cryogenic, low-pressure air into high-temperature, high-pressure air, which then enters the molten salt heat exchanger to heat the cryogenic molten salt. The cooled circulating working fluid exchanges heat with the environment after being worked by the expander, and finally enters the compressor again for compression, completing one cycle. The heated cryogenic molten salt is stored in a high-temperature molten salt tank. Utilizing the molten salt for heat storage reduces the unit's output, stores the high-grade energy of the steam, and broadens the unit's operating load range.

[0058] During peak electricity consumption: open the fourth valve 16 and the sixth valve 24, close the first valve 12, the second valve 13, the third valve 15 and the fifth valve 22, use high-temperature molten salt to heat the deaerator feedwater, and after exchanging heat with high-temperature molten salt in the fourth molten salt heat exchanger 26, it enters the steam supply header as industrial steam.

[0059] Specifically, the fourth and sixth valves are activated, and the high-temperature molten salt pump is started. The high-temperature molten salt heats the deaerator feedwater in the molten salt heat exchanger. After passing through the molten salt heat exchanger, the deaerator feedwater is used as industrial steam and enters the steam supply header. By utilizing the heat storage capacity of the molten salt, the unit's power generation is increased, meeting industrial steam demand while achieving peak power output.

[0060] In summary, this application achieves multi-dimensional technological breakthroughs by deeply coupling the Carnot battery system with the thermal power unit's thermal system, with the core being the synergistic storage of extracted steam thermal energy and heat pump cycle thermal energy, thus comprehensively solving the operational pain points of existing thermal power units.

[0061] In terms of wide-range load regulation, traditional thermal power units are limited by their thermodynamic cycle characteristics and can only operate stably within a narrow load range. At low loads, they are prone to problems such as efficiency decline and parameter fluctuations. This application breaks through this limitation by employing a dual-path energy regulation system of "steam extraction and thermal storage + heat pump cycle thermal storage": During normal electricity consumption, the unit operates in the medium-to-high load range, extracting reheat steam to meet industrial steam supply needs while simultaneously recovering steam superheat through a molten salt heat exchanger and converting it into thermal energy for storage. This avoids energy waste and reserves energy for subsequent load regulation. During off-peak electricity consumption, on the one hand, the main steam system extracts reheat steam to generate intermediate-pressure steam adapted to the steam supply parameters, achieving simultaneous steam supply and thermal storage in conjunction with molten salt heat exchange. On the other hand, the heat pump cycle unit is activated to convert excess electrical energy into high-temperature thermal energy stored in the molten salt tank. This dual thermal storage path significantly reduces the actual power generation output requirement of the unit, enabling it to stably reduce to zero output or even achieve "negative output" operation (i.e., net energy absorption through the energy storage system). During peak electricity consumption, the thermal energy stored in the molten salt is released to supplement the unit's energy and support full-load operation. This design allows thermal power units to achieve full-range coverage from full load to deep low load, achieving the goal of wide-range flexible operation.

[0062] Regarding the improvement of deep peak-shaving capabilities, this application addresses the pain points of poor energy storage-unit matching and low surplus power utilization in traditional peak-shaving technologies. Traditional peak-shaving methods either rely on electric boilers to consume surplus power, which is inefficient, or rely on steam accumulators, which have limited capacity. In contrast, this application combines the heat pump cycle of Carnot batteries with molten salt thermal energy storage to efficiently convert surplus power and the heat energy generated by steam extraction into stable molten salt thermal energy storage. The energy storage system is deeply adapted to the unit's thermal cycle, eliminating energy conversion losses and storage degradation issues. During peak-shaving, precise valve control of each unit enables coordinated response of thermal energy storage, heat release, and steam supply, avoiding lifespan degradation caused by frequent equipment start-ups and shutdowns. This significantly improves the flexibility and reliability of unit peak-shaving, allowing thermal power units to better adapt to load fluctuations in grids with a high proportion of renewable energy, thus supporting the stable operation of the grid.

[0063] In balancing peak demand and industrial steam supply security, this application breaks through the traditional technical dilemma of "mutual exclusion between steam supply and power generation." Traditional units often need to reduce industrial steam supply if they need to generate full load during peak periods; conversely, ensuring steam supply reduces power generation output, making it difficult to meet peak demand simultaneously. This application, however, achieves synergy between the two through energy dispatching via molten salt thermal storage: during peak electricity demand, there is no need to extract steam for power generation; instead, the previously stored high-temperature molten salt heats the deaerator feedwater, directly meeting industrial steam demand and allowing the unit to generate full load to achieve peak targets. During normal and off-peak electricity demand, parameter control through molten salt heat exchange ensures stable industrial steam pressure and temperature, preventing fluctuations in steam supply parameters from affecting user production. This design allows the unit to improve peak shaving and peak capacity while consistently ensuring reliable industrial steam supply, achieving multiple goals of "no loss of steam supply during peak shaving and no energy shortage during peak periods," providing key technical support for the efficient operation of thermal power units in new power systems.

[0064] Furthermore, embodiments of this application also provide a storage medium, the storage medium including a stored program, wherein, when the program is executed, it controls the device where the storage medium is located to perform the above-mentioned... Figure 3 A method for operating a combined heat and power (CHP) unit.

[0065] Furthermore, embodiments of this application also provide an electronic device, the electronic device including a storage medium; and one or more processors, the storage medium being coupled to the processors, the processors being configured to execute program instructions stored in the storage medium; the program instructions, when executed, perform as described above. Figure 3 The above describes a method for operating a combined heat and power (CHP) unit.

[0066] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0067] It is understood that the relevant features in the above methods and apparatus can be referenced interchangeably. Furthermore, the terms "first," "second," etc., in the above embodiments are used to distinguish between embodiments and do not represent the superiority or inferiority of any particular embodiment.

[0068] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0069] The algorithms and displays provided herein are not inherently related to any particular computer, virtual system, or other device. Various general-purpose systems can also be used in conjunction with the teachings herein. Based on the above description, the required structure for constructing such systems is obvious. Furthermore, this application is not directed to any particular programming language. It should be understood that the content of this application described herein can be implemented using various programming languages, and the above description of specific languages ​​is for the purpose of disclosing the best mode of implementation of this application. Additionally, the memory may include non-persistent memory in computer-readable media, random access memory (RAM), and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory may include at least one memory chip.

[0070] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0071] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0072] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0073] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0074] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0075] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0076] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0077] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A combined heat and power (CHP) unit, comprising a power generation unit and a thermal storage unit, wherein the thermal storage unit includes a molten salt heat exchanger, characterized in that, The combined heat and power unit includes: A heat pump circulation unit is connected to a heat storage unit. The heat pump circulation unit includes a compressor, an expander, a first heat exchanger, and a second heat exchanger. The heat pump circulation unit is used to convert surplus electricity from the power generation unit into heat energy for storage during off-peak electricity demand. The compressor's working fluid outlet is connected to the working fluid inlet of the molten salt heat exchanger, the molten salt heat exchanger's working fluid outlet is connected to the working fluid inlet of the first heat exchanger, the first heat exchanger's working fluid outlet is connected to the working fluid inlet of the expander, the expander's working fluid outlet is connected to the working fluid inlet of the second heat exchanger, and the second heat exchanger's working fluid outlet is connected to the compressor's working fluid inlet. The compressor is used to compress low-temperature, low-pressure air into high-temperature, high-pressure air using surplus electricity during off-peak hours. After entering the molten salt heat exchanger, the high-temperature, high-pressure air exchanges heat with the low-temperature molten salt from the heat storage unit to transfer heat to the low-temperature molten salt and form high-temperature molten salt. The high-temperature molten salt is then transported to the high-temperature molten salt tank of the heat storage unit for storage.

2. The cogeneration unit according to claim 1, wherein the cogeneration unit comprises a heat release unit and an industrial steam supply unit, characterized in that, The combined heat and power unit includes: The heat pump circulation unit is connected to the heat storage unit, the heat storage unit is connected to the heat release unit, the heat storage unit is connected to the industrial steam supply unit, the heat release unit is connected to the industrial steam supply unit, the industrial steam supply unit is connected to the power generation unit, and the power generation unit is connected to the heat storage unit.

3. The cogeneration unit according to claim 2, characterized in that, The combined heat and power unit includes: The power generation unit includes a boiler, a steam turbine, a condenser, a low-pressure heater, a deaerator, and a high-pressure heater. The steam turbine unit includes a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder. It uses the steam generated in the boiler to do work and coaxially drives the generator to generate electricity. The condenser is used to cool the steam discharged from the low-pressure cylinder into condensate and input the condensate into the low-pressure heater; the low-pressure heater is used to heat the condensate in the low-pressure heater using steam drawn from the low-pressure cylinder; the deaerator is used to heat the feedwater from the low-pressure heater using steam drawn from the intermediate-pressure cylinder; the high-pressure heater is used to heat the feedwater from the deaerator outlet pump using steam drawn from the high-pressure cylinder.

4. The combined heat and power unit according to claim 3, characterized in that, The main steam transmission from the boiler outlet of the power generation unit has two paths, namely a first path and a second path. The combined heat and power unit includes: The first path is for the main steam from the boiler outlet to enter the high-pressure cylinder of the turbine unit, and the steam thermal energy is converted into mechanical energy by the expansion and work process of the high-pressure cylinder to provide power for the generator to generate electricity. The second path is for the main steam from the boiler outlet to be transported to the ejector through the first valve. The reheat steam generated by the boiler is transported in three ways. The first way is to transport the reheat steam to the ejector through the second valve. The reheat steam is used as the ejector fluid of the ejector and works with the active fluid to generate intermediate pressure steam. The second way is to transport the reheat steam to the second molten salt heat exchanger of the heat storage unit through the third valve. The heat is transferred to the low temperature molten salt through the heat exchange process to achieve thermal energy storage. The third way is to transport the reheat steam directly into the intermediate pressure cylinder of the steam turbine to do work. The steam after doing work enters the low pressure cylinder to complete expansion and do work. The heat release unit has a fourth valve, which is located between the deaerator and the fourth molten salt heat exchanger.

5. The cogeneration unit according to claim 4, characterized in that, The combined heat and power unit includes: The thermal storage unit includes a high-temperature molten salt tank, a low-temperature molten salt tank, a high-temperature molten salt pump, a low-temperature molten salt pump, a first molten salt heat exchanger, a second molten salt heat exchanger, a molten salt heat exchanger, and a fourth molten salt heat exchanger; The molten salt inlet of the high-temperature molten salt tank is connected to the first molten salt heat exchanger, the second molten salt heat exchanger, and the medium outlet of the molten salt heat exchanger. The molten salt outlet of the high-temperature molten salt tank is connected to the medium inlet of the fourth molten salt heat exchanger, forming a first molten salt circulation loop. The molten salt circulation loop is used to receive and store the high-temperature molten salt generated after heat exchange in the first molten salt heat exchanger, the second molten salt heat exchanger, and the molten salt heat exchanger, and to transport the high-temperature molten salt to the fourth molten salt heat exchanger when heat release is required. The molten salt outlet of the cryogenic molten salt tank is connected to the first molten salt heat exchanger, the second molten salt heat exchanger, and the medium inlet of the molten salt heat exchanger; the molten salt inlet of the cryogenic molten salt tank is connected to the medium outlet of the fourth molten salt heat exchanger, forming a second molten salt circulation loop. The second molten salt circulation loop is used to provide cryogenic molten salt to the first molten salt heat exchanger, the second molten salt heat exchanger, and the molten salt heat exchanger, and to receive cryogenic molten salt formed by the fourth molten salt heat exchanger after heat release and cooling. A sixth valve is provided between the high-temperature molten salt tank and the fourth molten salt heat exchanger, and a fifth valve is provided between the low-temperature molten salt tank and the junction of the conveying pipelines of the first molten salt heat exchanger, the second molten salt heat exchanger, and the molten salt heat exchanger. The fifth valve is used to control the opening and closing of the conveying path of high-temperature molten salt to the fourth molten salt heat exchanger and the conveying path of low-temperature molten salt to the first molten salt heat exchanger, the second molten salt heat exchanger, and the molten salt heat exchanger, respectively. The high-temperature molten salt pump is installed on the molten salt conveying pipeline between the high-temperature molten salt tank and the fourth molten salt heat exchanger, and is used to provide power for the flow of high-temperature molten salt from the high-temperature molten salt tank to the fourth molten salt heat exchanger. The cryogenic molten salt pump is installed on the molten salt delivery pipeline between the cryogenic molten salt tank and the first molten salt heat exchanger, the second molten salt heat exchanger, and the molten salt heat exchanger, and is used to provide power for the flow of cryogenic molten salt from the cryogenic molten salt tank to each molten salt heat exchanger.

6. A method for operating a combined heat and power (CHP) unit, characterized in that, The method is applied to the cogeneration unit according to claim 5, wherein the cogeneration unit comprises a power generation unit, a thermal storage unit, an industrial steam supply unit, and a heat pump cycle unit, including: Obtain power consumption status; When the power consumption is at its lowest point, the passage between the heat storage unit, the heat pump cycle unit, and the industrial steam supply unit is opened. The compressor in the heat pump cycle unit is started to use the surplus electricity to compress the low-temperature, low-pressure air into high-temperature, high-pressure air. The high-temperature, high-pressure air enters the molten salt heat exchanger in the heat storage unit to exchange heat with the low-temperature molten salt. The generated high-temperature molten salt is transported to the high-temperature molten salt tank in the heat storage unit for storage. The reheat steam is drawn into the generator unit by the ejector to generate intermediate pressure steam. The intermediate pressure steam is then discharged into the industrial steam supply unit after exchanging heat with low-temperature molten salt in the molten salt heat exchanger of the thermal storage unit.

7. The method according to claim 6, wherein the combined heat and power unit has a heat release unit, characterized in that, include: When the power consumption is at its peak, after connecting the heat exchange path between the heat storage unit and the heat release unit and closing the linkage path between the heat storage unit and the heat pump circulation unit, the high-temperature molten salt pump in the heat storage unit is started. The high-temperature molten salt stored in the high-temperature molten salt tank is transported to the fourth molten salt heat exchanger associated with the heat release unit by the high-temperature molten salt pump. The fourth molten salt heat exchanger is then used to exchange heat with the deaerator feedwater of the power generation unit. After the deaerator feedwater reaches the preset steam supply parameters after heat exchange, it is discharged into the industrial steam supply unit.

8. The method according to claim 6, characterized in that, include: When the power consumption status is normal, switch the connection valve between the thermal storage unit and the industrial steam supply unit so that the industrial steam supply unit can directly extract reheat steam from the power generation unit. The molten salt heat exchanger passage in the thermal storage unit, which is used to absorb the superheat of steam, is opened so that the reheated steam can transfer its superheat to the low-temperature molten salt in the thermal storage unit during the steam supply process. After the low-temperature molten salt absorbs heat and transforms into high-temperature molten salt, it is transported to a high-temperature molten salt tank for storage through the transmission pipeline of the heat storage unit, thus completing the thermal energy reserve. At the same time, the turbine unit of the power generation unit is controlled to maintain operation within the rated load range. Through the coordinated heat exchange of the low-pressure heater, deaerator, and high-pressure heater, the thermal cycle of the power generation unit is ensured to be stable.

9. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the storage medium to perform a cogeneration unit operation method as described in any one of claims 6-8.

10. An electronic device, characterized in that, The device includes at least one processor, at least one memory connected to the processor, and a bus; wherein the processor and the memory communicate with each other through the bus; the processor is used to call program instructions in the memory to execute a cogeneration unit operation method according to any one of claims 6-8.

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