High-temperature heat pump coupling back pressure unit combined heat supply system

Abstract

The invention relates to a high-temperature heat pump coupling back pressure unit combined heat supply system which comprises a back pressure machine, a heat storage medium circulation loop, a high-temperature medium circulation loop, a low-temperature medium circulation loop and a low-temperature deoxygenated water heat exchange main path, the low-temperature deoxygenated water heat exchange main path is connected with the low-temperature medium circulation loop through a low-temperature heat exchanger, and the low-temperature deoxygenated water heat exchange main path is connected with the high-temperature medium circulation loop through a high-temperature heat exchanger. The exhaust steam of the back pressure machine exchanges heat with the low-temperature medium; the high-temperature medium circulation loop and the low-temperature medium circulation loop are connected through a regenerative heat exchanger, so that a high-temperature medium exchanges heat with a low-temperature medium; the heat storage medium circulation loop is connected with the high-temperature medium circulation loop through a high-temperature heat exchanger, so that the high-temperature medium exchanges heat with the heat storage medium; and the heat storage medium circulation loop is connected with the low-temperature deoxygenated water heat exchange main path through a heat exchanger group, so that the low-temperature deoxygenated water exchanges heat with the heat storage medium. In this way, new energy green electricity can be consumed, and green carbon reduction of the unit is achieved; and self-produced coal power can be consumed, and thermoelectric decoupling of the unit is achieved.

Description

Technical Field

[0001] This disclosure relates to the field of steam turbine power generation technology, and more specifically, to a high-temperature heat pump coupled back-pressure unit combined heating system. Background Technology

[0002] As the country increases its requirements for the peak-shaving capacity of thermal power units, these units need to operate efficiently and across a wide load range to enable more renewable energy to be fed into the grid or to absorb some of it. Compared to condensing units, which are relatively flexible in operation, extraction back-pressure units are limited by the stability of steam parameters and pressures from industrial users, making it difficult to achieve thermal-electric decoupling. In some industrial parks, the demand for steam supply during the day is much higher than at night, resulting in high daytime top heat load pressure for back-pressure units and low nighttime heat load, causing operational difficulties or even shutdowns. Low loads lead to a surge in coal consumption, and frequent day-night peak-shaving will cause frequent start-ups and shutdowns of back-pressure units, affecting their lifespan. Summary of the Invention

[0003] The purpose of this disclosure is to provide a high-temperature heat pump coupled with a back-pressure unit for combined heating, so as to at least partially solve the problems existing in the related art.

[0004] To achieve the above objectives, this disclosure provides a high-temperature heat pump coupled with a back-pressure turbine combined heating system, including a back-pressure turbine and a high-temperature heat pump system. The high-temperature heat pump system includes a heat storage medium circulation loop, a high-temperature medium circulation loop, a low-temperature medium circulation loop, and a low-temperature deoxygenated water heat exchange main line. The low-temperature deoxygenated water heat exchange main line is connected to the low-temperature medium circulation loop via a low-temperature heat exchanger, allowing the exhaust steam from the back-pressure turbine to exchange heat with the low-temperature medium. The high-temperature medium circulation loop is connected to the low-temperature medium circulation loop via a regenerative heat exchanger, allowing the high-temperature medium to exchange heat with the low-temperature medium. The heat storage medium circulation loop is connected to the high-temperature medium circulation loop via a high-temperature heat exchanger, allowing the high-temperature medium to exchange heat with the heat storage medium. The heat storage medium circulation loop is connected to the low-temperature deoxygenated water heat exchange main line via a heat exchanger assembly, allowing the low-temperature deoxygenated water to exchange heat with the heat storage medium. The back pressure unit is installed on the deoxygenated water heat exchange branch. The back pressure unit and the high-temperature medium circulation loop are used to heat the low-temperature medium. The high-temperature medium circulation loop is used to heat the heat storage medium. The heat storage medium circulation loop is used to heat the deoxygenated water in the deoxygenated water heat exchange branch. The heated deoxygenated water is used to supply heat to the outside.

[0005] Optionally, the high-temperature medium circulation loop includes the regenerating heat exchanger, the high-temperature heat exchanger, and the compressor connected in sequence, and the low-temperature medium circulation loop includes the low-temperature heat exchanger, the regenerating heat exchanger, and the expander connected in sequence, with the output end of the expander connected to the compressor. The expander is used to cool and depressurize the low-temperature medium, and the compressor is used to heat and depressurize the high-temperature medium.

[0006] Optionally, the heat storage medium circulation loop includes a low-temperature heat storage tank, the high-temperature heat exchanger, the high-temperature heat storage tank, and the heat exchanger group connected in sequence.

[0007] Optionally, the low-temperature deoxygenated water heat exchange main circuit includes the back pressure machine, the low-temperature heat exchanger, the low-pressure deaerator, the second feed water pump, the heat exchanger group, and the steam supply pipe connected in sequence, and the back pressure machine is connected to the steam supply pipe.

[0008] Optionally, the heat exchanger assembly includes a superheater, an evaporator, and a preheater.

[0009] Optionally, in the heat storage medium circulation loop, the superheater is arranged adjacent to the downstream of the high-temperature heat storage tank, and the preheater is arranged adjacent to the upstream of the low-temperature heat storage tank.

[0010] Optionally, in the low-temperature deoxygenated water heat exchange main circuit, the preheater is arranged adjacent to the downstream of the low-pressure deaerator, and the superheater is arranged adjacent to the upstream of the steam supply pipe.

[0011] Optionally, the high-temperature heat pump coupled back pressure unit combined heating system further includes a power supply branch, which includes the steam turbine generator, transformer, disconnecting switch, frequency converter, drive motor and expander connected in sequence.

[0012] Optionally, the low-pressure deaerator is also connected to a first feedwater pump.

[0013] Optionally, in the low-temperature deoxygenated water heat exchange main circuit, two parallel heating branches are provided between the heat exchanger group and the steam supply pipe. The steam supply pipe includes a low-pressure steam supply pipe and a high-pressure steam supply pipe, which are respectively provided on the two heating branches.

[0014] Through the above technical solution, this combined heating system optimizes the day and night heating and power supply needs of the back-pressure turbine unit. The high-temperature heat pump system absorbs green electricity and converts it into steam, coupling it with the back-pressure turbine unit for peak external heating. This enables the absorption of green electricity for heating, increases electricity value through the heat pump, improves the operational flexibility of the back-pressure turbine unit, and better adapts to fluctuations in external heat load. When the external heat load demand is low at night, the high-temperature heat pump system absorbs the heat from the exhaust steam of the back-pressure turbine, storing the nighttime heat. During the day, when the peak heat load of the back-pressure turbine unit is insufficient, the stored heat is released, enhancing the unit's peak heat load capacity. The high-temperature heat pump configuration allows for its own thermoelectric decoupling, and simultaneously absorbs surplus green electricity from the grid based on the grid's green electricity surplus, reducing carbon emissions per unit of power generation / heat supply.

[0015] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a high-temperature heat pump coupled back-pressure unit combined heating system provided in an exemplary embodiment of this disclosure; Figure 2 This is a schematic diagram of the operation of a high-temperature heat pump coupled back pressure unit combined heating system provided in an exemplary embodiment of this disclosure at night; Figure 3 This is a schematic diagram of the operation of a high-temperature heat pump coupled back pressure unit combined heating system provided in an exemplary embodiment of this disclosure during the daytime.

[0017] Explanation of reference numerals in the attached figures 1-Back pressure compressor; 2-Heat storage medium circulation loop; 21-Low-temperature heat storage tank; 22-High-temperature heat storage tank; 3-High-temperature medium circulation loop; 31-Compressor; 4-Low-temperature medium circulation loop; 41-Expander; 5-Low-temperature deoxygenated water heat exchange main circuit; 51-Deaerator; 511-First feed water pump; 512-Second feed water pump; 52-Low-pressure steam supply pipe; 53-High-pressure steam supply pipe; 501-Heating branch circuit; 500-Desuperheater and pressure reducer; 6-Power supply branch circuit; 61-Steam turbine generator; 62-Transformer; 63-Disconnecting switch; 64-Variable frequency drive; 65-Drive motor; 7-Gearbox; 10-Low-temperature heat exchanger; 20-Regenerative heat exchanger; 30-High-temperature heat exchanger; 40-Heat exchanger group; 401-Superheater; 402-Evaporator; 403-Preheater Detailed Implementation The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0018] The terms "first," "second," etc., used in this disclosure are for distinguishing one element from another and do not indicate any order or importance. In this disclosure, when the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0019] Reference Figures 1 to 3 This disclosure provides a high-temperature heat pump coupled with a back-pressure turbine combined heating system. This system includes a back-pressure turbine 1 and a high-temperature heat pump system. The high-temperature heat pump system includes a heat storage medium circulation loop 2, a high-temperature medium circulation loop 3, a low-temperature medium circulation loop 4, and a low-temperature deoxygenated water heat exchange main circuit 5. Specifically, the back-pressure turbine can adopt parameters such as medium pressure, high pressure, ultra-high pressure, subcritical, or supercritical. The back-pressure turbine can be a pure back-pressure turbine or an extraction back-pressure turbine. The low-temperature deoxygenated water heat exchange main circuit 5 is connected to the low-temperature medium circulation loop 4 via a low-temperature heat exchanger 10, allowing the exhaust steam from the back-pressure turbine 1 to exchange heat with the low-temperature medium. Here, the high-temperature heat pump heat source can be the exhaust steam from the back-pressure turbine, the extraction steam from the back-pressure turbine, or a mixture of exhaust and extraction steam. The system consists of a steam-heated medium circulation loop 3 and a low-temperature medium circulation loop 4 connected by a regenerative heat exchanger 20 to exchange heat between the high-temperature and low-temperature media. A heat storage medium circulation loop 2 and a high-temperature medium circulation loop 3 are connected by a high-temperature heat exchanger 30 to exchange heat between the high-temperature medium and the heat storage medium. The heat storage medium circulation loop 2 and the low-temperature deoxygenated water heat exchange main circuit 5 are connected by a heat exchanger group 40 to exchange heat between the low-temperature deoxygenated water and the heat storage medium. A back pressure unit 1 is installed on the deoxygenated water heat exchange branch circuit 5. The back pressure unit 1 and the high-temperature medium circulation loop 3 are used to heat the low-temperature medium, the high-temperature medium circulation loop 3 is used to heat the heat storage medium, and the heat storage medium circulation loop 2 is used to heat the deoxygenated water in the deoxygenated water heat exchange branch circuit 5. The heated deoxygenated water is then used for external heat supply. Liquid heat storage and heat exchange media can be flexibly selected according to the temperature requirements of the external heat supply parameters, enabling economies of scale. Specifically, the circulating medium of a high-temperature heat pump can be air, nitrogen, argon, or other gases; the minimum pressure of the high-temperature heat pump system can be slightly positive or positive; the heat storage medium can be molten salt, heat transfer oil, silicate, or other flowable heat storage media; the heat exchanger can be a tubular, plate, hairpin, or printed circuit board type heat exchanger; if multiple heat exchangers are used in the same stage, they can be connected in series, in parallel, or in a series-parallel combination. This technology can be applied to the retrofitting of existing back-pressure units as well as to the construction of new back-pressure units.

[0020] Through the above technical solution, when the power grid requires appropriate peak shaving from the back-pressure turbine, the excess power of the back-pressure turbine is used to drive the high-temperature heat pump system. During the day, when the back-pressure turbine supplies steam to the outside, and the heat load is at its peak, the steam from the heat exchanger assembly of the high-temperature heat pump system is led to the steam supply pipe and combined with the extracted or exhausted steam from the back-pressure turbine before being supplied to the outside. At night, when the back-pressure turbine supplies steam to the outside and the heat load is low, thermoelectric decoupling is difficult. To maintain the stable operation of the back-pressure turbine, the high-temperature heat pump system is put into operation. The high-temperature heat pump system is powered by the generator of the back-pressure turbine or by green electricity from the grid. The exhaust steam from the back-pressure turbine serves as the cold-end heat source of the high-temperature heat pump. The heat generated by the high-temperature heat pump is stored in the high-temperature heat storage tank in the heat storage medium circulation loop, thus achieving thermoelectric decoupling and ensuring the stability of the external steam supply.

[0021] This combined heating system optimizes the day and night heating and power supply needs of the back-pressure turbine unit. The high-temperature heat pump system absorbs green electricity, converts it into steam, and couples it with the back-pressure turbine unit for peak external heating. This enables the absorption of green electricity for heating, increases power output through the heat pump, enhances the operational flexibility of the back-pressure turbine unit, and better adapts to fluctuations in external heat load. When external heat load demand is low at night, the high-temperature heat pump system absorbs heat from the exhaust steam of the back-pressure turbine, storing this nighttime heat. During the day, when the peak heat load of the back-pressure turbine unit is insufficient, the stored heat is released, enhancing the unit's peak heat load capacity. The high-temperature heat pump configuration allows for its own thermoelectric decoupling, while simultaneously absorbing surplus green electricity from the grid, reducing carbon emissions per unit of power generation / heat supply.

[0022] Among them, reference Figure 1The high-temperature medium circulation loop 3 may include a regenerating heat exchanger 20, a high-temperature heat exchanger 30, and a compressor 31 connected in sequence. The low-temperature medium circulation loop 4 may include a low-temperature heat exchanger 10, a regenerating heat exchanger 20, and an expander 41 connected in sequence. The output end of the expander 41 is connected to the compressor 31. Specifically, the expander 41 and the compressor 31 are connected by a gearbox 7. The expander 41 is used to cool and depressurize the low-temperature medium, and the compressor 31 is used to heat and depressurize the high-temperature medium. Specifically, the compressor 31 may be single-stage or multi-stage, integrated or split-type; the compressor 31 and the expander 41 may be coaxial or split-shaft arranged. The circulating medium of the high-temperature heat pump system can be dehumidified (water, steam) air or other inert gases. The circulating medium first enters the compressor 31, where it is compressed to increase its pressure and temperature. The high-temperature, high-pressure medium then enters the high-temperature heat exchanger 30 and exchanges surface heat with the low-temperature heat storage tank 21 from the heat storage medium circulation loop 2 after pressure increase, thus cooling the heat storage medium. The cooled high-temperature circulating medium then enters the regenerative heat exchanger 20 to exchange heat with the low-pressure, low-temperature circulating medium at the outlet of the expander 41. After heat exchange, the high-pressure, high-temperature circulating medium is cooled; the high-pressure, low-temperature circulating medium enters the expander 41, expands and does work, and its temperature decreases and its pressure drops to around 1 atmosphere. The shaft power output by the expander 41 is used to drive the compressor 31; the low-temperature, low-pressure circulating medium sequentially exchanges heat with the exhaust steam from the back compressor 1 in the low-temperature heat exchanger 10, and then exchanges heat with the regenerating heat exchanger 20, and its temperature rises, completing one cycle and converting electrical energy into heat energy. At the same time, part of the heat from the exhaust steam of the back compressor is recovered to the high-temperature heat storage tank 22 in the heat storage medium circulation loop 2, realizing the value-added of electrical energy.

[0023] Among them, reference Figure 1 The heat storage medium circulation loop 2 may include a low-temperature heat storage tank 21, a high-temperature heat exchanger 30, a high-temperature heat storage tank 22, and a heat exchanger group 40 connected in sequence. The heat storage medium in the low-temperature heat storage tank 21 exchanges heat with the high-temperature medium in the high-temperature heat exchanger 30 and the high-temperature medium circulation loop 3. The heated heat storage medium enters the high-temperature heat storage tank 22 to store heat.

[0024] Among them, reference Figure 1The low-temperature deoxygenated water heat exchange main circuit 5 may include a back pressure compressor 1, a low-temperature heat exchanger 10, a low-pressure deaerator 51, a second feed water pump 512, a heat exchanger group 40, and a steam supply pipe connected in sequence. The back pressure compressor 1 is connected to the steam supply pipe. The exhaust steam from the back pressure compressor 1 enters the low-temperature heat exchanger 10 to exchange heat with the low-temperature medium in the low-temperature medium circulation loop 4. After releasing heat, the exhaust steam from the back pressure compressor 1 drains into the low-pressure deaerator 51. The water in the low-pressure deaerator 51 is pressurized by the second feed water pump 512 and then passes through the heat exchanger group 40 to be heated to superheated steam for external heating. The heat exchanger group 40 exchanges heat with the heat storage medium in the high-temperature heat storage tank 22, which has been pressurized by the high-temperature medium pump. After flowing through the heat exchanger group 40, the high-temperature heat storage medium becomes a low-temperature heat storage medium and returns to the low-temperature heat storage tank 21. At this point, the heat release stage is completed.

[0025] Specifically, the heat exchanger assembly 40 may include a superheater 401, an evaporator 402, and a preheater 403. When the back-pressure unit supplies industrial steam, the deaerated brine from the power plant is heated sequentially through the preheater 403, evaporator 402, and superheater 401 to achieve the process from water to superheated steam; the heat storage medium is pressurized and then cooled step by step through the superheater 401, evaporator 402, and preheater 403 before flowing back to the low-temperature heat storage tank 21.

[0026] Furthermore, referring to Figure 1 In the heat storage medium circulation loop 2, the superheater 401 can be arranged adjacent to the downstream of the high-temperature heat storage tank 22, and the preheater 403 can be arranged adjacent to the upstream of the low-temperature heat storage tank 21. The high-temperature heat storage medium in the high-temperature heat storage tank 22 flows sequentially through the superheater 401, the evaporator 402, and the preheater 403 before becoming a low-temperature heat storage medium and returning to the low-temperature heat storage tank 21.

[0027] Furthermore, referring to Figure 1 In the low-temperature deoxygenated water heat exchange main circuit 5, the preheater 403 can be arranged adjacent to the downstream of the low-pressure deaerator 51, and the superheater 401 can be arranged adjacent to the upstream of the steam supply pipe. The water in the low-pressure deaerator 51 is heated to superheated steam after passing through the heat exchanger preheater 403, evaporator 402, and superheater 401 in sequence. In the preheater 403, the high-pressure demineralized (oxygenated) water is heated from subcooled water to saturated water, and then flows to the evaporator 402. In the evaporator 402, the saturated water absorbs heat at constant pressure to saturated steam. The saturated steam in the evaporator 402 is heated to the required steam temperature in the superheater 401 and then supplied to the outside of the steam supply header.

[0028] As an exemplary embodiment of this disclosure, reference is made to Figure 1The high-temperature heat pump coupled back-pressure unit combined heating system may also include a power supply branch 6, which may include a steam turbine generator 61, a transformer 62, a disconnecting switch 63, a frequency converter 64, a drive motor 65, and an expander 41 connected in sequence. When the power grid needs the back-pressure unit to absorb some of the renewable energy green electricity, the generator outlet voltage is regulated by adding an independent transformer at the generator outlet or by using a plant service transformer, and the power supply to the high-temperature heat pump system and the load speed regulation are realized through the disconnecting switch 63 and the frequency converter 64.

[0029] Specifically, refer to Figure 1 The low-pressure deaerator 51 can also be connected to a first feedwater pump 511. The exhaust steam and water from the back pressure unit 1 after heat release are discharged into the low-pressure deaerator 51, pressurized by the first feedwater pump 511, absorbed heat in the low-pressure heater, and then circulated in the main thermal system.

[0030] In some embodiments, refer to Figure 1 In the low-temperature deoxygenated water heat exchange main circuit 5, two parallel heating branches 501 can be provided between the heat exchanger group 40 and the steam supply pipe. The steam supply pipe can include a low-pressure steam supply pipe 52 and a high-pressure steam supply pipe 53, which are respectively set on the two heating branches 501. During the day, when the back pressure unit supplies steam to the outside, when the heat load is at its peak, the steam at the outlet of the superheater 401 in the high-temperature heat pump system is divided into two paths. One path is led to the high-pressure steam supply pipe 53, which is then combined with the steam extracted by the back pressure unit and supplied to the outside. The other path goes through the desuperheater and pressure reducer 500 to the low-pressure steam supply pipe 52, which is then combined with the exhaust steam from the back pressure unit and supplied to the outside. The operation of the desuperheater and pressure reducer 500 is determined based on the external high and low pressure steam demand.

[0031] The working process of this high-temperature heat pump coupled with a back-pressure unit combined heating system is as follows: At night, as Figure 2As shown, the thermal storage coupled back-pressure turbine achieves thermoelectric decoupling. When the high-temperature heat pump system stores heat, the isolating switch 63 is closed, and the transformer 62 at the outlet of the steam turbine generator 61 adjusts the voltage and sends it to the frequency converter 64 to drive the drive motor 65 to rotate the entire shaft system. The low-temperature circulating medium at the outlet of the expander 41 absorbs heat from the exhaust steam of the back-pressure turbine in the low-temperature heat exchanger 10. After absorbing heat, the circulating medium enters the regenerating heat exchanger 20. The exhaust steam from the back-pressure turbine, after releasing heat, drains into the low-pressure deaerator 51. After being pressurized by the first feedwater pump 511, it absorbs heat in the low-pressure heater and then circulates in the main thermal system. In heat exchanger 20, the high-temperature heat pump system achieves heat exchange between high- and low-temperature circulating media. The high-pressure low-temperature circulating media rotates and does work in the expander 41, while the high-temperature low-pressure media enters the compressor 31 and is compressed into a high-temperature high-pressure circulating media. After exiting the compressor 31, the high-temperature media enters the high-temperature heat exchanger 30 to exchange heat with the heat storage medium on a surface. After heat exchange, the high-temperature media enters the regenerative heat exchanger 20 for further heat exchange and cooling. The heat storage medium enters the high-temperature heat exchanger 30 from the low-temperature heat storage tank 21 via the low-temperature medium pump to absorb heat. After absorbing heat, the heat storage medium enters the high-temperature heat storage tank 22, thus completing the heat storage stage.

[0032] During the day, such as Figure 3 As shown, the exothermic coupling back pressure turbine achieves peak heating. When the high-temperature heat pump system releases heat, the water in the low-pressure deaerator 51 is pressurized by the second feed water pump 512 and then sequentially passes through the preheater 403, evaporator 402, and superheater 401 to be heated to superheated steam for external heating. In the preheater 403, the high-pressure demineralized (oxygenated) water is heated from subcooled water to saturated water, and then flows to the evaporator 402. In the evaporator 402, the saturated water absorbs heat at constant pressure to become saturated steam. The saturated steam in 402 is heated to the required steam temperature in the superheater 401 and then supplied to the outside of the medium and low pressure steam header. The heat exchanger superheater 401, evaporator 402, preheater 403 and high temperature heat storage tank 22 are pressurized by the high temperature medium pump and exchange heat. The high temperature heat storage medium flows through the superheater 401, evaporator 402 and preheater 403 in sequence and becomes low temperature heat storage medium and returns to the low temperature heat storage tank 21. At this time, the heat release stage is completed.

[0033] According to calculations, if the back pressure heating parameters are 0.45MPa, 175℃, 100t / h, 330 days of operation per year for the back pressure unit, 6 hours / day of peak high-temperature heat pump heating, and COP of 1.35, the annual heating supply will be 198,000 tons, consuming 114 million kWh of green electricity. Based on a coal consumption of 300g / kWh for power generation, the annual coal saving will be 35,000 tons.

[0034] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0035] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0036] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A high-temperature heat pump coupled with a back-pressure unit for combined heating, characterized in that, The system includes a back-pressure compressor and a high-temperature heat pump system. The high-temperature heat pump system comprises a heat storage medium circulation loop, a high-temperature medium circulation loop, a low-temperature medium circulation loop, and a low-temperature deoxygenated water heat exchange main line. The low-temperature deoxygenated water heat exchange main line is connected to the low-temperature medium circulation loop via a low-temperature heat exchanger, allowing the exhaust steam from the back-pressure compressor to exchange heat with the low-temperature medium. The high-temperature medium circulation loop is connected to the low-temperature medium circulation loop via a regenerative heat exchanger, allowing the high-temperature medium to exchange heat with the low-temperature medium. The heat storage medium circulation loop is connected to the high-temperature medium circulation loop via a high-temperature heat exchanger, allowing the high-temperature medium to exchange heat with the heat storage medium. The heat storage medium circulation loop is connected to the low-temperature deoxygenated water heat exchange main line via a heat exchanger assembly, allowing the low-temperature deoxygenated water to exchange heat with the heat storage medium. The back pressure unit is installed on the deoxygenated water heat exchange branch. The back pressure unit and the high-temperature medium circulation loop are used to heat the low-temperature medium. The high-temperature medium circulation loop is used to heat the heat storage medium. The heat storage medium circulation loop is used to heat the deoxygenated water in the deoxygenated water heat exchange branch. The heated deoxygenated water is used to supply heat to the outside.

2. The high-temperature heat pump coupled back-pressure unit combined heating system according to claim 1, characterized in that, The high-temperature medium circulation loop includes the regenerating heat exchanger, the high-temperature heat exchanger, and the compressor connected in sequence. The low-temperature medium circulation loop includes the low-temperature heat exchanger, the regenerating heat exchanger, and the expander connected in sequence. The output end of the expander is connected to the compressor. The expander is used to cool and depressurize the low-temperature medium, and the compressor is used to heat and depressurize the high-temperature medium.

3. The high-temperature heat pump coupled back-pressure unit combined heating system according to claim 1 or 2, characterized in that, The heat storage medium circulation loop includes a low-temperature heat storage tank, a high-temperature heat exchanger, a high-temperature heat storage tank, and a heat exchanger group connected in sequence.

4. The high-temperature heat pump coupled back-pressure unit combined heating system according to claim 3, characterized in that, The low-temperature deoxygenated water heat exchange main circuit includes the back pressure machine, the low-temperature heat exchanger, the low-pressure deaerator, the second feed water pump, the heat exchanger group, and the steam supply pipe connected in sequence, and the back pressure machine is connected to the steam supply pipe.

5. The high-temperature heat pump coupled back-pressure unit combined heating system according to claim 4, characterized in that, The heat exchanger assembly includes a superheater, an evaporator, and a preheater.

6. The high-temperature heat pump coupled back-pressure unit combined heating system according to claim 5, characterized in that, In the heat storage medium circulation loop, the superheater is arranged adjacent to the downstream of the high-temperature heat storage tank, and the preheater is arranged adjacent to the upstream of the low-temperature heat storage tank.

7. The high-temperature heat pump coupled back-pressure unit combined heating system according to claim 5, characterized in that, In the low-temperature deoxygenated water heat exchange main circuit, the preheater is arranged adjacent to the downstream of the low-pressure deaerator, and the superheater is arranged adjacent to the upstream of the steam supply pipe.

8. The high-temperature heat pump coupled back-pressure unit combined heating system according to claim 2, characterized in that, The high-temperature heat pump coupled back pressure unit combined heating system also includes a power supply branch, which includes the steam turbine generator, transformer, disconnecting switch, frequency converter, drive motor and expander connected in sequence.

9. The high-temperature heat pump coupled back-pressure unit combined heating system according to claim 1, characterized in that, The low-pressure deaerator is also connected to a first water supply pump.

10. The high-temperature heat pump coupled back-pressure unit combined heating system according to claim 1, characterized in that, In the low-temperature deoxygenated water heat exchange main circuit, two parallel heating branches are provided between the heat exchanger group and the steam supply pipe. The steam supply pipe includes a low-pressure steam supply pipe and a high-pressure steam supply pipe, which are respectively provided on the two heating branches.

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