Novel medium-high temperature coupling heat pump unit and operation method

Abstract

This invention discloses a novel medium-high temperature coupled heat pump unit and its operation method. The semi-efficiency heating absorption heat pump cycle subsystem is coupled to a low-grade heat energy deep recovery and upgrading utilization subsystem via a high-pressure condenser-generator. This subsystem is also coupled to a heterogeneous energy flow reconstruction and coupling utilization subsystem via a condenser-evaporator and an evaporator-condenser. Primary return water sequentially enters the low-pressure absorber and high-pressure absorber, is heated to 90°C, and then enters the primary heating network. The refrigerant vapor outlet of the low-pressure generator, the refrigerant inlet and outlet of the condenser-evaporator, the refrigerant water pump inlet and outlet, and the refrigerant inlet and outlet of the evaporator-condenser are sequentially connected to the refrigerant inlet of the high-pressure absorber. The refrigerant vapor outlet of the high-pressure condenser-generator is connected to the refrigerant vapor inlet of the low-pressure absorber. This invention reduces irreversible thermal losses through multi-mass energy flow optimization reconstruction and coupling utilization, achieving efficient utilization of low-grade heat energy and producing 90°C medium-high temperature hot water.

Description

Technical Field

[0001] This invention belongs to the field of water source heat pump technology, specifically a novel medium- and high-temperature coupled heat pump unit and its operation method. Background Technology

[0002] Multi-energy coupled, large-temperature-difference, low-temperature district heating is a core technological path for promoting the low-carbon energy transformation of urban buildings in northern China. The efficient development and utilization of low-temperature waste heat resources, geothermal resources, solar energy, and other new energy sources are important technical measures for achieving multi-energy coupled, large-temperature-difference, low-temperature heating. Heating-type absorption heat pumps, because they can utilize medium- and low-grade heat sources to produce higher-temperature heat energy, are widely used in industrial waste heat recovery and urban heating in northern China.

[0003] Conventional single-stage absorption heat pumps require a high chemical potential driving force for their generation and absorption processes, typically necessitating medium- to high-grade thermal energy as the driving heat source. When faced with low-grade industrial waste heat or shallow geothermal energy (15℃~45℃), traditional absorption heat pumps cannot operate, leading to a waste of low-grade energy. If a pure compression heat pump is used to achieve a large temperature range increase, it will result in an excessively high high / low pressure ratio in the single-unit compressor, severely degrading unit performance. This high pressure ratio not only causes a precipitous drop in compressor volumetric efficiency but also leads to severely overheated exhaust temperatures, resulting in carbonization and coking of the refrigerant oil, causing mechanical failures and shortening equipment lifespan.

[0004] Traditional medium- and high-temperature absorption heat pump cycles require medium- and high-grade heat energy as the driving heat source, and the unit's heating coefficient is relatively small; traditional single-effect heating absorption heat pumps require low-temperature cold sources, resulting in a low heating coefficient and low utilization efficiency of low-grade heat energy. Summary of the Invention

[0005] To address the problems existing in the background technology, this invention provides a novel medium-high temperature coupled heat pump unit. It integrates a low-pressure-ratio electric vapor compression heat pump cycle system into a heat-driven absorption heat pump cycle, and couples the two in an orderly manner through refrigerant and water pipelines. This achieves thermodynamic process reconstruction and multi-mass energy flow coupling for enhanced efficiency, fully leveraging the advantages of both heat pump cycles and the thermophysical properties of the working fluid. This improves the coefficient of performance (COP) of the heat pump cycle, significantly reduces the power consumption of the compressor, and provides technical support for the deep development and utilization of low-temperature waste heat, geothermal, and solar energy resources. The technical solution includes: a heat source water supply pipeline, a heat source return water pipeline, a low-grade heat energy deep recovery and upgrading utilization subsystem, a half-efficiency heating absorption heat pump cycle subsystem, a heterogeneous energy flow reconstruction and coupling utilization subsystem, a primary return water pipeline, and a primary water supply pipeline. Among them, the half-efficiency heating absorption heat pump cycle subsystem is coupled with the low-grade heat energy deep recovery and upgrading utilization subsystem through a high-pressure condenser-generator, and the half-efficiency heating absorption heat pump cycle subsystem is coupled with the heterogeneous energy flow reconstruction and coupling utilization subsystem through a condenser-evaporator and an evaporator-condenser.

[0006] The semi-efficiency heating absorption heat pump cycle subsystem includes: a low-pressure generator, a refrigerant pump, a high-pressure absorber, a high-temperature solution heat exchanger, a low-pressure absorber, and a low-temperature solution heat exchanger. The primary return water sequentially enters the low-pressure absorber and the high-pressure absorber, is heated to 90°C, and then enters the primary heating network as primary supply water. The heat source supply water pipeline, the driving heat source water inlet of the low-pressure generator, the driving heat source water outlet of the low-pressure generator, and the heat source return water pipeline are connected in sequence.

[0007] The dilute solution outlet of the low-pressure absorber is connected to the dilute solution inlet of the low-pressure generator via the dilute solution side of the low-temperature solution heat exchanger. The dilute solution outlet of the high-pressure absorber is connected to the dilute solution inlet of the high-pressure condenser-generator via the dilute solution side of the high-temperature solution heat exchanger. The refrigerant vapor outlet of the low-pressure generator is connected to the refrigerant vapor inlet of the condenser-evaporator. The refrigerant water outlet of the condenser-evaporator is connected to the refrigerant water pump inlet. The refrigerant water pump outlet is connected to the refrigerant water inlet of the evaporator-condenser. The refrigerant vapor outlet of the evaporator-condenser is connected to the refrigerant vapor inlet of the high-pressure absorber. The refrigerant vapor outlet of the high-pressure condenser-generator is connected to the refrigerant vapor inlet of the low-pressure absorber.

[0008] The concentrated solution outlet of the low-pressure generator is connected to the concentrated solution inlet of the low-pressure absorber via the concentrated solution side of the low-temperature solution heat exchanger. The refrigerant water flowing out of the low-pressure generator at 37°C sequentially enters the condenser-evaporator, refrigerant pump, and evaporator-condenser for heat exchange, reaching 66°C before entering the high-pressure absorber to release heat and condense into a liquid state. It mixes with the concentrated solution from the high-pressure condenser-generator to form a dilute solution. The refrigerant vapor flowing out of the high-pressure condenser-generator is at 59°C. The concentrated solution outlet of the high-pressure condenser-generator is connected to the concentrated solution inlet of the high-pressure absorber via the concentrated solution side of the high-temperature solution heat exchanger.

[0009] In the low-grade heat energy deep recovery and upgrading utilization subsystem, the working fluid outlet of the evaporator, the working fluid inlet on the low-temperature side of the regenerator A, the low-temperature side outlet of the regenerator A, and the working fluid inlet of the compressor A are connected. The working fluid outlet of the compressor A, the working fluid inlet of the high-pressure condenser-generator, the working fluid outlet of the high-pressure condenser-generator, the working fluid inlet on the high-temperature side of the regenerator A, the working fluid outlet on the high-temperature side of the regenerator A, the throttle valve A, and the working fluid inlet of the evaporator are connected in sequence to form a loop.

[0010] In the heterogeneous energy flow reconstruction and coupling utilization subsystem, the working fluid outlet of the condenser-evaporator is sequentially connected to the working fluid inlet on the low temperature side of the regenerator B, the working fluid outlet on the low temperature side of the regenerator B, the working fluid inlet and outlet of the compressor B, the working fluid inlet of the evaporator-condenser, the working fluid outlet of the evaporator-condenser is sequentially connected to the working fluid inlet on the high temperature side of the regenerator B, the working fluid outlet on the high temperature side of the regenerator B, and the working fluid inlet of the throttle valve B and the condenser-evaporator to form a loop.

[0011] The working fluid of the semi-efficiency heating absorption heat pump cycle subsystem is lithium bromide solution; the working fluid of the heterogeneous energy flow reconstruction and coupling utilization subsystem is carbon dioxide or R410A; and the working fluid of the low-grade heat energy deep recovery and upgrading utilization subsystem is carbon dioxide or R410A.

[0012] The semi-efficiency heating absorption heat pump cycle subsystem recovers condensation heat that would otherwise be released into the environment by coupling a high-pressure condenser-generator with a low-grade heat energy deep recovery and upgrading utilization subsystem, and by coupling the semi-efficiency heating absorption heat pump cycle subsystem with a condenser-evaporator, an evaporator-condenser, and a heterogeneous energy flow reconstruction and coupling utilization subsystem. Simultaneously, the condensation heat is upgraded by consuming electrical energy in the low-grade heat energy deep recovery and upgrading utilization subsystem and the heterogeneous energy flow reconstruction and coupling utilization subsystem, and is directly used to drive the working fluid water vaporization of the evaporator-condenser. This is suitable for heating heat pump cycles that use low-grade heat energy to achieve high-temperature hot water production in large temperature difference heat exchange production.

[0013] The low-pressure generator's drive heat source water outlet is connected to the heat source return water pipeline via the low-temperature heat source water side of the evaporator.

[0014] The heat source supply water and the heat source return water are respectively low-temperature waste heat supply water at 45℃ and low-temperature waste heat return water at 30℃.

[0015] A three-way valve VS1, a valve V2, and a three-way valve VS3 are sequentially installed between the low-pressure generator driving heat source water outlet and the evaporator driving heat source water inlet. A three-way valve VS4, a valve V3, and a three-way valve VS2 are sequentially installed between the evaporator low-temperature heat source outlet and the heat source return water pipeline. The third path of the three-way valve VS1 and the third path of the three-way valve VS2 are connected by the valve V1. The third path of the three-way valve VS3 is connected to the shallow geothermal water supply pipeline through the valve V4. The third path of the three-way valve VS4 is connected to the shallow geothermal return water pipeline through the valve V5.

[0016] The heat source supply water and heat source return water are low-temperature waste heat supply water at 45℃ and low-temperature waste heat return water at 35℃, respectively; the temperatures of shallow geothermal supply water and shallow geothermal return water are 15℃ and 10℃, respectively.

[0017] The primary return water pipeline is connected in sequence to the cold side of the double-effect absorption heat pump, the cold side of the heat source water-to-water heat exchanger, and the primary return water pipeline of the heat source station; the primary supply water pipeline is connected in sequence to the cold side of the steam-to-water heat exchanger and the primary supply water pipeline of the heat source station.

[0018] The hot side of the heat source water-to-water heat exchanger is connected to the third low-temperature waste heat supply and return water pipeline; the hot side of the double-effect absorption heat pump is connected to the second low-temperature waste heat supply and return water pipeline; and the high-temperature side of the steam-to-water heat exchanger is connected to the power plant's low-pressure extraction steam supply and return pipeline.

[0019] The primary water supply from the heat source station, at 130°C, is cooled to 10°C in a high-temperature coupled heat pump with a large temperature difference at the primary energy station. It then returns to the heat source station as primary return water via the primary heating network, where it is reheated, and the cycle continues. The secondary water supply from the primary energy station, at 90°C, first enters the low-temperature, large-temperature-difference heat exchanger at the secondary energy station via the secondary heating network, where it is cooled to 25°C. It then returns to the primary energy station as secondary return water via the secondary heating network, where it is reheated, and the cycle continues. In the secondary energy station, the tertiary return water, at 35°C, is heated to 45°C by a low-temperature, large-temperature-difference heat exchanger, and then distributed to heat users as tertiary supply water.

[0020] The large temperature difference medium-high temperature coupled heat pump unit includes: a high-temperature water-to-water heat exchanger, a low-temperature water-to-water heat exchanger, a primary water supply pipeline, a primary water return pipeline, a secondary water supply pipeline, a secondary water return pipeline, a first high-pressure generator, a condenser A, a throttling device A, a condenser B, a throttling device B, a first evaporator, a first absorber, a first solution heat exchanger, a first low-pressure generator, a low-temperature water-to-water heat exchanger, and a high-temperature water-to-water heat exchanger; the absorption heat pump is orderly coupled with the high-temperature water-to-water heat exchanger and the low-temperature water-to-water heat exchanger through the primary water pipeline and the secondary water pipeline, so as to realize heat flow reconstruction and orderly cascade efficient utilization of energy;

[0021] The dilute solution outlet of the first absorber is connected to the dilute solution inlet of the first solution heat exchanger. The dilute solution outlet of the first solution heat exchanger is connected to the dilute solution inlets of the first low-pressure generator and the first high-pressure generator, respectively. The concentrated solution outlets of the first high-pressure generator and the first low-pressure generator are connected to the concentrated solution inlet of the first solution heat exchanger. The concentrated solution outlet of the first solution heat exchanger is connected to the concentrated solution inlet of the first absorber. The refrigerant vapor outlet of the first high-pressure generator is connected to the refrigerant vapor inlet of condenser A. The refrigerant water outlet of condenser A is connected to the refrigerant water inlet of condenser B through throttling device A. The refrigerant vapor outlet of the first low-pressure generator is connected to the refrigerant water inlet of condenser B. The refrigerant water outlet of condenser B is connected to the refrigerant water inlet of the first evaporator through throttling device B. The refrigerant vapor outlet of the first evaporator is connected to the refrigerant vapor inlet of the first absorber.

[0022] The primary water supply pipeline is connected to the primary water inlet of the first high-pressure generator; the primary water outlet of the first high-pressure generator is connected to the primary water inlet of the first low-pressure generator; the primary water outlet of the first low-pressure generator is connected to the primary water inlet of the high-temperature water-to-water heat exchanger; the primary water outlet of the high-temperature water-to-water heat exchanger is connected to the primary water inlet of the low-temperature water-to-water heat exchanger; the primary water outlet of the low-temperature water-to-water heat exchanger is connected to the primary water inlet of the first evaporator; and the primary water outlet of the first evaporator is connected to the primary return water. The secondary return water pipeline is connected to the secondary water inlet of the low-temperature water-to-water heat exchanger; the secondary water outlet of the low-temperature water-to-water heat exchanger is connected to the secondary water inlet of the first absorber; the secondary water outlet of the first absorber is connected to the secondary water inlet of condenser B; the secondary water outlet of condenser B is connected to the secondary water inlet of condenser A; the secondary water outlet of condenser A is connected to the secondary water inlet of the high-temperature water-to-water heat exchanger; and the secondary water outlet of the high-temperature water-to-water heat exchanger is connected to the secondary water supply pipeline.

[0023] A novel operating method for a medium- and high-temperature coupled heat pump unit is also provided, the technical solutions of which include: single heat source operation mode and multi-heat source coordinated operation mode;

[0024] The single heat source operation mode is as follows: In the semi-efficiency heating absorption heat pump cycle subsystem, the mixed solution of working fluid A and working fluid B is heated by low-temperature waste heat water supplied by a 45℃ driving heat source in the low-pressure generator, generating some working fluid B vapor. The working fluid B vapor enters the condenser-evaporator through the refrigerant channel. After condensing and releasing heat in the condenser-evaporator with a condensation temperature of 12℃, working fluid B is pressurized by the refrigerant pump and enters the evaporator-condenser. After absorbing heat and evaporating in the evaporator-condenser with an evaporation temperature of 66℃, it enters the high-pressure absorber through the refrigerant channel. At the same time, the mixed solution of working fluid A and working fluid B undergoes a temperature change at 59℃ in the high-pressure condenser-generator. After being heated to a certain temperature, some working fluid B vapor is generated. The working fluid B vapor enters the low-pressure absorber through the refrigerant channel. The remaining concentrated solution in the low-pressure generator enters the low-pressure absorber after heat exchange in the low-temperature solution heat exchanger. It absorbs the refrigerant vapor generated from the high-pressure condenser-generator and becomes a dilute solution. After heat exchange in the low-temperature solution heat exchanger, it enters the low-pressure generator to complete the low-pressure solution cycle. The remaining concentrated solution in the high-pressure condenser-generator enters the high-pressure absorber after heat exchange in the high-temperature solution heat exchanger. It absorbs the refrigerant vapor from the evaporator and becomes a dilute solution. After heat exchange in the high-temperature solution heat exchanger, it enters the high-pressure condenser-generator to complete the high-pressure solution cycle. In the low-grade heat energy deep recovery and upgrading utilization subsystem, low-temperature waste heat circulating water from the low-pressure generator outlet enters the evaporator as a low-temperature heat source and is further cooled to 30°C in the evaporator before being discharged. The working fluid C first absorbs heat at an evaporation temperature of 28°C and becomes working fluid C vapor. Then, it enters compressor A through regenerator A and is pressurized therein. Next, it enters the high-pressure condenser-generator and is condensed at a condensation temperature of 63°C. Finally, it passes through regenerator A and throttling valve A sequentially before entering the evaporator, thus completing a single working fluid C cycle. In the heterogeneous energy flow reconstruction and coupling utilization subsystem, the working fluid D first absorbs heat at an evaporation temperature of 10°C in the condenser-evaporator and evaporates into working fluid D vapor. Next, it enters compressor B through regenerator B, is pressurized in compressor B, and then enters the evaporator-condenser. Then, the working fluid D vapor is condensed at a condensation temperature of 68°C in the evaporator-condenser. Finally, it passes through regenerator B and throttling valve B sequentially before entering the condenser-evaporator, thus completing a single working fluid D cycle.

[0025] The multi-heat source coordinated operation mode is as follows: 45℃ low-temperature waste heat supply water enters the hot side of the low-pressure generator to drive the absorption heat pump to run and discharge 35℃ low-temperature waste heat return water. 15℃ shallow geothermal supply water enters the hot side of the evaporator to release heat and then discharges 10℃ shallow geothermal return water through the pipeline. At the same time, shallow geothermal and low-temperature waste heat are utilized.

[0026] In the semi-efficiency heating absorption heat pump cycle subsystem, the mixed solution of working fluid A and working fluid B is heated by low-temperature waste heat water supplied by a 45°C driving heat source in the low-pressure generator, generating some working fluid B vapor. The working fluid B vapor enters the condenser-evaporator through the refrigerant channel. After condensing and releasing heat in the condenser-evaporator at a condensation temperature of 12°C, working fluid B is pressurized by the refrigerant pump and enters the evaporator-condenser. After absorbing heat and evaporating in the evaporator-condenser at an evaporation temperature of 66°C, it enters the high-pressure absorber through the refrigerant channel. Simultaneously, the mixed solution of working fluid A and working fluid B is heated at a generation temperature of 59°C in the high-pressure condenser-generator. Afterwards, some working fluid B vapor is generated, which enters the low-pressure absorber through the refrigerant channel. The remaining concentrated solution in the low-pressure generator enters the low-pressure absorber after heat exchange in the low-temperature solution heat exchanger, where it absorbs the refrigerant vapor generated from the high-pressure condenser-generator and becomes a dilute solution. After heat exchange in the low-temperature solution heat exchanger, it enters the low-pressure generator to complete the low-pressure solution cycle. The remaining concentrated solution in the high-pressure condenser-generator enters the high-pressure absorber after heat exchange in the high-temperature solution heat exchanger, where it absorbs the refrigerant vapor from the evaporator and becomes a dilute solution. After heat exchange in the high-temperature solution heat exchanger, it enters the high-pressure condenser-generator to complete the high-pressure solution cycle. In the low-grade heat energy deep recovery and upgrading utilization subsystem, shallow geothermal water, as a low-temperature heat source, enters the evaporator to release heat and cool down to 10°C before being discharged. The working fluid C first absorbs heat at an evaporation temperature of 8°C, becoming working fluid C vapor. Then, it enters compressor A through regenerator A and is pressurized therein. Next, it enters the high-pressure condenser-generator and is condensed at a condensation temperature of 63°C. Finally, it passes through regenerator A and throttling valve A sequentially before entering the evaporator, thus completing a single working fluid C cycle. In the heterogeneous energy flow reconstruction and coupling utilization subsystem, the working fluid D first absorbs heat at an evaporation temperature of 10°C in the condenser-evaporator and evaporates into working fluid D vapor. Next, it enters compressor B through regenerator B, is pressurized in compressor B, and then enters the evaporator-condenser. The working fluid D vapor is then condensed at a condensation temperature of 68°C in the evaporator-condenser. Finally, it passes through regenerator B and throttling valve B sequentially before entering the condenser-evaporator, thus completing a single working fluid D cycle.

[0027] Working medium A is lithium bromide, working medium B is water; working medium C is carbon dioxide or R410A; working medium D is carbon dioxide or R410A.

[0028] The beneficial effects of this invention are as follows:

[0029] 1. This invention breaks through the theoretical limit of traditional absorption heat pumps requiring high-temperature drive to produce medium- and high-temperature hot water. It utilizes ultra-low grade heat energy to drive a coupled heat pump to produce medium- and high-temperature hot water at 90°C. By introducing a cascade design of a low-pressure generator and a high-pressure generator, it achieves efficient and in-depth utilization of ultra-low grade heat energy, thereby expanding the boundaries of industrial energy conservation and consumption reduction and geothermal resource utilization.

[0030] 2. This invention replaces the reliance of traditional absorption systems on external cooling towers and external high-temperature heat sources. It utilizes an independently operating compression cycle to achieve energy flow reconstruction and synergistic utilization within the system. Specifically, it couples the condenser and evaporator in the heterogeneous energy flow reconstruction and coupling with the evaporator and condenser in the half-efficiency heating absorption heat pump cycle subsystem, respectively. This allows for the precise recovery of condensation heat that would otherwise be released into the environment by the condenser-evaporator on the absorption heat pump side. Furthermore, it upgrades the system by consuming a small amount of electrical energy through the compression heat pump cycle, directly using this energy to drive the vaporization of the working fluid water in the evaporator-condenser on the absorption heat pump side.

[0031] 3. This invention couples the condenser with the high-pressure generator in the semi-efficiency heating absorption heat pump cycle subsystem to form a "high-pressure condenser-generator". Through an independent compression cycle, a small amount of electrical energy is consumed to deeply recover and upgrade the heat energy of the low-temperature heat source water. In the "semi-efficiency heating absorption heat pump cycle", the 40°C primary heat network return water flows through the low-pressure absorber and the high-pressure absorber in sequence and is heated to 90°C in stages, achieving ultra-large temperature difference heating.

[0032] 4. In semi-efficiency heating absorption heat pumps, directly attempting to produce high-temperature return water using existing technology and then heating the 40°C primary network return water with a high-temperature solution would result in significant losses. This invention heats the primary network water in two stages, from low to high temperature. First, the 40°C primary network circulating water is preheated in a low-pressure absorber, significantly reducing irreversible losses. Then, the high-grade heat generated by the strong chemical absorption potential of high-concentration lithium bromide under high pressure is used to heat the preheated primary network circulating water to the target temperature of 90°C.

[0033] In the low-pressure generator, the inlet temperature of the dilute solution is 42℃ and the outlet temperature of the concentrated solution is 37℃. In the low-pressure absorber, the inlet temperature of the concentrated solution is 45℃ and the outlet temperature of the dilute solution is 50℃. This allows the low-pressure absorber to better absorb the refrigerant vapor from the high-pressure condenser-generator at 59℃, thus efficiently preheating the primary circulating water.

[0034] In the high-pressure generator, the inlet temperature of the dilute solution is 64℃ and the outlet temperature of the concentrated solution is 59℃. The 89℃ high-pressure concentrated solution absorbs high-pressure refrigerant vapor in the high-pressure absorber and becomes a 94℃ dilute solution, which leaves the high-pressure absorber to heat the preheated primary heating network circulating water to the target temperature of 90℃. The high-pressure generator makes full use of the extremely strong chemical absorption potential of high-concentration lithium bromide under high pressure to perform secondary heating of the primary network water.

[0035] 5. When applied to a multi-energy coupled ultra-large temperature difference centralized heating system, this invention realizes multi-energy coupling and efficient utilization. It also achieves ultra-large temperature difference transmission between the primary and secondary heating networks by connecting the high-temperature coupled heat pump unit with the large temperature difference in the primary energy station with the low-temperature heat exchanger unit with the large temperature difference in the secondary energy station, thereby improving the low-temperature heat energy conversion and transfer performance and transmission efficiency. Attached Figure Description

[0036] Figure 1 This is a schematic flowchart of Embodiment 1 of a novel medium-high temperature coupled heat pump unit and its operation method according to the present invention.

[0037] Figure 2 This is a flowchart illustrating Embodiment 2 of the present invention.

[0038] Figure 3 This is a schematic diagram of the process of the high-temperature coupled heat pump unit with large temperature difference in Embodiment 2 of the present invention. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to the accompanying drawings.

[0040] like Figure 1 The embodiment 1 of the present invention shown includes: a heat source supply and return water pipeline (heat source supply water and heat source return water), a low-grade heat energy deep recovery and upgrading utilization subsystem, a semi-efficiency heating absorption heat pump cycle subsystem, a heterogeneous energy flow reconstruction and coupling utilization subsystem, and a primary heating network supply and return water pipeline (primary return water and primary supply water). The semi-efficiency heating absorption heat pump cycle subsystem, the heterogeneous energy flow reconstruction and coupling utilization subsystem, and the low-grade heat energy deep recovery and upgrading utilization subsystem are coupled. Through multi-mass energy flow optimization reconstruction and coupling efficiency enhancement utilization, the irreversible losses of the system are reduced and the energy efficiency of producing medium and high temperature hot water is improved, realizing the efficient utilization of low-temperature heat energy and producing medium and high temperature hot water at 90°C.

[0041] The novel medium-high temperature coupled heat pump unit in Example 1 mainly includes: a half-efficiency heating absorption heat pump cycle subsystem, a low-grade heat energy deep recovery and upgrading utilization subsystem, and a heterogeneous energy flow reconstruction and coupling utilization subsystem. The working fluid pair of the half-efficiency heating absorption heat pump cycle subsystem is lithium bromide solution (lithium bromide is the absorbent as working fluid A, and water is the refrigerant as working fluid B); the working fluid C (refrigerant) of the low-grade heat energy deep recovery and upgrading utilization subsystem is carbon dioxide or R410A; and the working fluid D (refrigerant) of the heterogeneous energy flow reconstruction and coupling utilization subsystem is carbon dioxide or R410A. Depending on the application scenario, the compressor type can be a reciprocating, centrifugal, or screw compressor. The semi-efficiency heating absorption heat pump cycle subsystem is coupled with the low-grade heat energy deep recovery and upgrading utilization subsystem through the high-pressure condenser-generator. The semi-efficiency heating absorption heat pump cycle subsystem is coupled with the condenser-evaporator, evaporator-condenser, and heterogeneous energy flow reconstruction and coupling utilization subsystem. Through the coupling of the three subsystems (semi-efficiency heating absorption heat pump cycle subsystem, low-grade heat energy deep recovery and upgrading utilization subsystem, and heterogeneous energy flow reconstruction and coupling utilization subsystem), the condensation heat that would otherwise be emitted into the environment is recovered. At the same time, in two subsystems (low-grade heat energy deep recovery and upgrading utilization subsystem and heterogeneous energy flow reconstruction and coupling utilization subsystem), a small amount of electrical energy is consumed to upgrade and utilize the condensation heat, which is directly used to drive the working fluid (lithium bromide solution) water vaporization of the evaporator-condenser. This is suitable for scenarios where low-grade heat energy is upgraded and utilized to efficiently produce medium and high-temperature hot water. This invention provides technical support and core equipment for the development of multi-energy coupled large temperature difference low-carbon heating, and promotes the clean and low-carbon transformation of urban heating in northern China.

[0042] The condenser of the semi-efficient heating absorption heat pump cycle subsystem is coupled with the evaporator in the heterogeneous energy flow reconstruction and coupling utilization subsystem to form a "condenser-evaporator". The evaporator of the semi-efficient heating absorption heat pump cycle subsystem is coupled with the condenser in the heterogeneous energy flow reconstruction and coupling utilization subsystem to form an "evaporator-condenser". The high-pressure generator of the semi-efficient heating absorption heat pump cycle subsystem is coupled with the condenser in the low-grade heat energy deep recovery and upgrading utilization subsystem to form a "high-pressure condenser-generator". Specifically, the semi-efficient heating absorption heat pump cycle subsystem is coupled with the low-grade heat energy deep recovery and upgrading utilization subsystem through the high-pressure condenser-generator. The high-pressure condenser-generator is used in the semi-efficient heating absorption heat pump cycle subsystem. In the absorption heat pump cycle subsystem, the high-pressure generator acts as the high-pressure condenser-generator; simultaneously, it acts as the condenser in the low-grade heat energy deep recovery and upgrading utilization subsystem; the half-efficiency heating absorption heat pump cycle subsystem is coupled with the heterogeneous energy flow reconstruction and coupling utilization subsystem through the condenser-evaporator, evaporator-condenser, and the heterogeneous energy flow reconstruction and coupling utilization subsystem; the condenser-evaporator acts as the condenser in the half-efficiency heating absorption heat pump cycle subsystem, and simultaneously, it acts as the evaporator in the heterogeneous energy flow reconstruction and coupling utilization subsystem; the evaporator-condenser acts as the evaporator in the half-efficiency heating absorption heat pump cycle subsystem, and simultaneously, it acts as the condenser in the heterogeneous energy flow reconstruction and coupling utilization subsystem.

[0043] In the semi-efficiency heating absorption heat pump cycle subsystem, the heat source supply water pipeline, the low-pressure generator, and the heat source return water pipeline are connected sequentially. The dilute solution outlet of the low-pressure absorber is connected to the dilute solution inlet of the low-pressure generator via the dilute solution side of the low-temperature solution heat exchanger, and the concentrated solution outlet of the low-pressure generator is connected to the concentrated solution inlet of the low-pressure absorber via the concentrated solution side of the low-temperature solution heat exchanger. The dilute solution outlet of the high-pressure absorber is connected to the dilute solution inlet of the high-pressure condenser-generator via the dilute solution side of the high-temperature solution heat exchanger, and the concentrated solution outlet of the high-pressure condenser-generator is connected to the concentrated solution inlet of the high-pressure absorber via the concentrated solution side of the high-temperature solution heat exchanger. The refrigerant vapor outlet of the low-pressure generator is connected to the refrigerant vapor inlet of the condenser-evaporator. The refrigerant water outlet of the condenser-evaporator is connected to the refrigerant water pump inlet, the refrigerant water pump outlet is connected to the refrigerant water inlet of the evaporator-condenser, the refrigerant vapor outlet of the evaporator-condenser is connected to the refrigerant vapor inlet of the high-pressure absorber, and the refrigerant vapor outlet of the high-pressure condenser-generator is connected to the refrigerant vapor inlet of the low-pressure absorber. The primary return water pipeline is connected to the primary water inlet of the low-pressure absorber, the primary water outlet of the low-pressure absorber is connected to the primary water inlet of the high-pressure absorber, and the primary water outlet of the high-pressure absorber is connected to the primary water supply pipeline. The primary return water is heated sequentially through the low-pressure absorber and the high-pressure absorber before leaving through the primary water supply. The primary water supply temperature is 90℃. The low-temperature waste heat supply water is connected to the low-pressure generator drive heat source water inlet.

[0044] In the low-grade heat energy deep recovery and upgrading subsystem, the working fluid outlet of the evaporator, the low-temperature working fluid inlet of the regenerator A, the low-temperature working fluid outlet of the regenerator A, and the working fluid inlet of the compressor A are connected. The working fluid outlet of the compressor A, the working fluid inlet of the high-pressure condenser-generator, the working fluid outlet of the high-pressure condenser-generator, the high-temperature working fluid inlet of the regenerator A, the high-temperature working fluid outlet of the regenerator A, the throttle valve A, and the working fluid inlet of the evaporator are connected in sequence to form a cycle.

[0045] In the heterogeneous energy flow reconstruction and coupling utilization subsystem, the working fluid outlet of the condenser-evaporator is sequentially connected to the working fluid inlet on the low temperature side of the regenerator B, the working fluid outlet on the low temperature side of the regenerator B, the working fluid inlet and outlet of the compressor B, the working fluid inlet of the evaporator-condenser, the working fluid outlet of the evaporator-condenser is sequentially connected to the working fluid inlet on the high temperature side of the regenerator B, the working fluid outlet on the high temperature side of the regenerator B, and the working fluid inlet of the throttle valve B and the condenser-evaporator to form a loop.

[0046] The novel medium-high temperature coupled heat pump unit and operation method in this embodiment can be applied to single heat source scenarios or multi-heat source scenarios based on the energy resource conditions of actual projects; the heat source supply and return water pipelines include single heat source connection methods and multi-heat source connection methods, and the operation methods include single heat source operation mode and multi-heat source collaborative operation mode;

[0047] When the heat source supply and return water pipeline is applied to a single heat source scenario, an evaporator is installed between the low-pressure generator and the heat source return water pipeline. The heat source water outlet of the low-pressure generator is connected to the heat source return water pipeline through the low-temperature heat source water side of the evaporator. The heat source supply water and the heat source return water are respectively low-temperature waste heat supply water (45℃) and low-temperature waste heat return water (30℃).

[0048] In single-heat-source operation, within the semi-efficiency heating absorption heat pump cycle subsystem, the mixed solution of working fluid A and working fluid B is heated in the low-pressure generator by low-temperature waste heat water supplied by a 45°C driving heat source, generating partial working fluid B vapor. This working fluid B vapor enters the condenser-evaporator through the refrigerant channel. Working fluid B condenses and releases heat in the condenser-evaporator at a condensation temperature of 12°C, and then, after being pressurized by the refrigerant pump, enters the evaporator-condenser. In the evaporator-condenser at an evaporation temperature of 66°C, it absorbs heat and evaporates before entering the high-pressure absorber through the refrigerant channel. Simultaneously, in the high-pressure condenser-generator, the mixed solution of working fluid A and working fluid B undergoes a temperature increase of 59°C. After being heated, a portion of the working fluid B vapor is generated. The working fluid B vapor enters the low-pressure absorber through the refrigerant channel. The remaining concentrated solution in the low-pressure generator enters the low-pressure absorber after heat exchange in the low-temperature solution heat exchanger. It absorbs the refrigerant vapor generated from the high-pressure condenser-generator and becomes a dilute solution. After heat exchange in the low-temperature solution heat exchanger, it enters the low-pressure generator to complete the low-pressure solution cycle. The remaining concentrated solution in the high-pressure condenser-generator enters the high-pressure absorber after heat exchange in the high-temperature solution heat exchanger. It absorbs the refrigerant vapor from the evaporator and becomes a dilute solution. After heat exchange in the high-temperature solution heat exchanger, it enters the high-pressure condenser-generator to complete the high-pressure solution cycle.

[0049] In the low-grade heat energy deep recovery and upgrading subsystem, low-temperature waste heat circulating water from the low-pressure generator outlet enters the evaporator as a low-temperature heat source and is further cooled to 30°C in the evaporator before being discharged. The working fluid C first absorbs heat at an evaporation temperature of 28°C and becomes working fluid C vapor; then, it enters compressor A through regenerator A and is pressurized therein; next, it enters the high-pressure condenser-generator and is condensed at a condensation temperature of 63°C; finally, it passes sequentially through regenerator A and throttling valve A before entering the evaporator, thus completing a single working fluid C cycle.

[0050] In the heterogeneous energy flow reconstruction and coupling utilization subsystem, the working fluid D first absorbs heat and evaporates into working fluid D vapor at an evaporation temperature of 10°C in the condenser-evaporator; then, it enters the compressor B through the regenerator B, is pressurized in the compressor B, and enters the evaporator-condenser; then, the working fluid D vapor is condensed at a condensation temperature of 68°C in the evaporator-condenser; finally, it enters the condenser-evaporator after passing through the regenerator B and the throttling valve B in sequence, thus completing a single working fluid D cycle.

[0051] When the heat source supply and return water pipeline is applied to a multi-heat source collaborative operation scenario, based on the single heat source scenario, a three-way valve VS1, a valve V2, and a three-way valve VS3 are sequentially installed between the low-pressure generator driving heat source water outlet and the evaporator driving heat source water side inlet. A three-way valve VS4, a valve V3, and a three-way valve VS2 are sequentially installed between the evaporator hot side outlet and the heat source return water. The third path of the three-way valve VS1 and the third path of the three-way valve VS2 are connected through valve V1. The third path of the three-way valve VS3 is connected to the shallow geothermal water supply through valve V4. The third path of the three-way valve VS4 is connected through valve V5.

[0052] The heat source supply water and heat source return water are respectively low-temperature waste heat supply water (45℃) and low-temperature waste heat return water (35℃); shallow geothermal supply water and shallow geothermal return water are also a type of heat source supply and return water, with temperatures of 15℃ and 10℃ respectively.

[0053] When applied to multi-heat source scenarios, valves V2 and V3 are closed, while valves V1, V4, and V5 are open. The low-pressure generator drives the heat source water outlet to connect to the low-temperature waste heat return water pipeline via tee VS1, valve V1, and tee VS2. The shallow geothermal water supply pipeline is connected to the evaporator low-temperature heat source water inlet via the third path of valve V4 and tee VS3. The evaporator low-temperature heat source water outlet is connected to the shallow geothermal return water pipeline via tee VS4 and valve V5. The third path of tee VS1 is connected to valve V2, tee VS3, and the evaporator low-temperature heat source water inlet. The evaporator low-temperature heat source water outlet is connected to tee VS4, valve V3, tee VS2, and the heat source return water pipeline (low-temperature waste heat return water).

[0054] Low-temperature waste heat water at 45℃ enters the hot side of the low-pressure generator to drive the absorption heat pump. After that, the low-temperature waste heat return water at 35℃ is discharged through valve V1. The shallow geothermal water at 15℃ enters the hot side of the evaporator through valve V4 to release heat. After that, the shallow geothermal return water at 10℃ is discharged through valve V5. At the same time, shallow geothermal heat and low-temperature waste heat are utilized.

[0055] In multi-heat source operation, within the semi-efficiency heating absorption heat pump cycle subsystem, the mixed solution of working fluid A and working fluid B is heated in the low-pressure generator by low-temperature waste heat water supplied by a 45°C driving heat source, generating partial working fluid B vapor. This working fluid B vapor enters the condenser-evaporator through the refrigerant channel. After condensing and releasing heat in the condenser-evaporator at a condensation temperature of 12°C, working fluid B is pressurized by the refrigerant pump and enters the evaporator-condenser. In the evaporator-condenser at an evaporation temperature of 66°C, it absorbs heat and evaporates before entering the high-pressure absorber through the refrigerant channel. Simultaneously, in the high-pressure condenser-generator, the mixed solution of working fluid A and working fluid B undergoes a temperature increase of 59°C. After being heated, a portion of the working fluid B vapor is generated. The working fluid B vapor enters the low-pressure absorber through the refrigerant channel. The remaining concentrated solution in the low-pressure generator enters the low-pressure absorber after heat exchange in the low-temperature solution heat exchanger. It absorbs the refrigerant vapor generated from the high-pressure condenser-generator and becomes a dilute solution. After heat exchange in the low-temperature solution heat exchanger, it enters the low-pressure generator to complete the low-pressure solution cycle. The remaining concentrated solution in the high-pressure condenser-generator enters the high-pressure absorber after heat exchange in the high-temperature solution heat exchanger. It absorbs the refrigerant vapor from the evaporator and becomes a dilute solution. After heat exchange in the high-temperature solution heat exchanger, it enters the high-pressure condenser-generator to complete the high-pressure solution cycle.

[0056] In the low-grade heat energy deep recovery and upgrading subsystem, shallow geothermal water, as a low-temperature heat source, enters the evaporator to release heat and cool down to 10°C before being discharged. The working fluid C first absorbs heat at an evaporation temperature of 8°C and becomes working fluid C vapor. Then, it enters the compressor A through the regenerator A and is pressurized therein. Next, it enters the high-pressure condenser-generator and is condensed at a condensation temperature of 63°C. Finally, it passes through the regenerator A and the throttling valve A in sequence and enters the evaporator, thus completing a single working fluid C cycle.

[0057] In the heterogeneous energy flow reconstruction and coupling utilization subsystem, the working fluid D first absorbs heat and evaporates into working fluid D vapor at an evaporation temperature of 10°C in the condenser-evaporator; then, it enters the compressor B through the regenerator B, is pressurized in the compressor B, and enters the evaporator-condenser; then, the working fluid D vapor is condensed at a condensation temperature of 68°C in the evaporator-condenser; finally, it enters the condenser-evaporator after passing through the regenerator B and the throttling valve B in sequence, thus completing a single working fluid D cycle.

[0058] When the multi-heat source connection mode is switched to a single heat source scenario, the single heat source is 45℃ low-temperature waste heat. At this time, valves V1, V4, and V5 are closed, while valves V2 and V3 are opened. The low-temperature waste heat supply water enters the low-pressure generator to drive the absorption heat pump. After that, it enters the evaporator through valve V2 to release heat and then exits through valve V3 as low-temperature waste heat return water. The return water passes through the low-pressure absorber and the high-pressure absorber in sequence and is heated twice before leaving through the primary water supply. The temperature of the primary water supply is 90℃.

[0059] The operating conditions and single heat source connection method are consistent; specifically, in the semi-efficiency heating absorption heat pump cycle subsystem, the mixed solution of working fluid A and working fluid B is heated by low-temperature waste heat water supplied by a 45℃ driving heat source in the low-pressure generator, generating some working fluid B vapor. The working fluid B vapor enters the condenser-evaporator through the refrigerant channel. After condensing and releasing heat in the condenser-evaporator with a condensation temperature of 12℃, working fluid B is pressurized by the refrigerant pump and enters the evaporator-condenser. After absorbing heat and evaporating in the evaporator-condenser with an evaporation temperature of 66℃, it enters the high-pressure absorber through the refrigerant channel; at the same time, the mixed solution of working fluid A and working fluid B in the high-pressure condenser-generator is heated by 5℃. After being heated to a temperature of 9°C, a portion of the working fluid B vapor is generated. The working fluid B vapor enters the low-pressure absorber through the refrigerant channel. The remaining concentrated solution in the low-pressure generator enters the low-pressure absorber after heat exchange in the low-temperature solution heat exchanger. It absorbs the refrigerant vapor generated from the high-pressure condenser-generator and becomes a dilute solution. After heat exchange in the low-temperature solution heat exchanger, it enters the low-pressure generator to complete the low-pressure solution cycle. The remaining concentrated solution in the high-pressure condenser-generator enters the high-pressure absorber after heat exchange in the high-temperature solution heat exchanger. It absorbs the refrigerant vapor from the evaporator and becomes a dilute solution. After heat exchange in the high-temperature solution heat exchanger, it enters the high-pressure condenser-generator to complete the high-pressure solution cycle.

[0060] In the low-grade heat energy deep recovery and upgrading subsystem, low-temperature waste heat circulating water from the low-pressure generator outlet enters the evaporator as a low-temperature heat source and is further cooled to 30°C in the evaporator before being discharged. The working fluid C first absorbs heat at an evaporation temperature of 28°C and becomes working fluid C vapor; then, it enters compressor A through regenerator A and is pressurized therein; next, it enters the high-pressure condenser-generator and is condensed at a condensation temperature of 63°C; finally, it passes sequentially through regenerator A and throttling valve A before entering the evaporator, thus completing a single working fluid C cycle.

[0061] In the heterogeneous energy flow reconstruction and coupling utilization subsystem, the working fluid D first absorbs heat and evaporates into working fluid D vapor at an evaporation temperature of 10°C in the condenser-evaporator; then, it enters the compressor B through the regenerator B, is pressurized in the compressor B, and enters the evaporator-condenser; then, the working fluid D vapor is condensed at a condensation temperature of 68°C in the evaporator-condenser; finally, it enters the condenser-evaporator after passing through the regenerator B and the throttling valve B in sequence, thus completing a single working fluid D cycle.

[0062] like Figure 2The illustrated embodiment 2 of the present invention is a multi-energy coupled ultra-large temperature difference centralized heating system based on embodiment 1, comprising: a heat source station, a primary energy station, a secondary energy station, a heat source water pipeline, a primary water pipeline, a secondary water pipeline, and a tertiary water pipeline. Primary supply water at 130°C flows out of the heat source station and is cooled to 10°C in a high-temperature coupled heat pump with a large temperature difference at the primary energy station. It then returns as primary return water through the primary heating network pipeline to the heat source station, where it is reheated, and this cycle repeats. Secondary supply water at 90°C flows out of the primary energy station and first enters the low-temperature type large temperature difference heat exchanger unit at the secondary energy station through the secondary heating network, where it is cooled to 25°C. It then returns as secondary return water through the secondary heating network to the primary energy station, where it is reheated, and this cycle repeats. In the secondary energy station, tertiary return water at 35°C is heated to 45°C by the low-temperature type large temperature difference heat exchanger unit and then distributed to heat users as tertiary supply water.

[0063] The heat source station includes: a heat source water-to-water heat exchanger, a double-effect absorption heat pump, a medium-high temperature coupled heat pump, and a steam-to-water heat exchanger; the primary return water pipeline of the medium-high temperature coupled heat pump is sequentially connected to the cold side of the double-effect absorption heat pump, the cold side of the heat source water-to-water heat exchanger, and the primary main return water pipeline of the heat source station; the primary supply water pipeline of the medium-high temperature coupled heat pump is sequentially connected to the cold side of the steam-to-water heat exchanger and the primary main supply water pipeline of the heat source station; the hot side of the heat source water-to-water heat exchanger is connected to the third low-temperature waste heat supply and return water pipeline. The circuits are connected. The hot side of the double-effect absorption heat pump is connected to the second low-temperature waste heat supply and return water pipeline, and the hot side of the steam-water heat exchanger is connected to the power plant's low-pressure extraction steam supply and return pipeline. The primary water return pipeline first passes through the cold side of the heat source water-water heat exchanger for heat exchange and temperature increase, then enters the double-effect absorption heat pump for further temperature increase, then enters the medium-high temperature coupled heat pump for further temperature increase, and finally enters the cold side of the steam-water heat exchanger for a temperature increase to 130°C, before entering the large temperature difference medium-high temperature coupled heat pump through the primary main water supply pipeline.

[0064] In this embodiment, the primary energy station is a high-temperature coupled heat pump unit with a large temperature difference, and the secondary energy station is a low-temperature large temperature difference heat exchanger unit. The low-temperature large temperature difference heat exchanger unit is formed by coupling a semi-efficiency absorption heat pump with a water-to-water heat exchanger. The secondary and tertiary heating network pipelines are coupled in an orderly manner through the low-temperature large temperature difference heat exchanger unit to achieve heat flow reconstruction optimization and deep utilization of coupling, thereby reducing the return water temperature of the low secondary heating network to 25°C. The number of primary energy stations is one or multiple stations connected in parallel, and the number of secondary energy stations is one or multiple stations connected in parallel.

[0065] Example 2 realizes multi-energy coupling and efficiency enhancement, and achieves ultra-large temperature difference transmission between the primary and secondary heat networks by using a high-temperature coupled heat pump unit with a large temperature difference in the primary energy station and a low-temperature heat exchanger unit with a large temperature difference in the secondary energy station, thereby improving the performance of low-temperature heat energy conversion and transfer, as well as the transmission efficiency.

[0066] In Example 2, as Figure 3 As shown, the large temperature difference medium-high temperature coupled heat pump unit used reduces irreversible system losses and improves the energy efficiency of producing medium-high temperature hot water through multi-mass energy flow optimization reconstruction and coupling efficiency enhancement; the working fluid pair of the absorption heat pump cycle is lithium bromide solution; the large temperature difference medium-high temperature coupled heat pump cools the primary heating network circulating water from 130℃ to 10℃, while simultaneously heating the secondary heating network circulating water from 25℃ to 90℃ in stages;

[0067] The large temperature difference medium-high temperature coupled heat pump unit includes: an absorption heat pump, a high-temperature water-to-water heat exchanger, and a low-temperature water-to-water heat exchanger. The working fluid of the absorption heat pump is lithium bromide solution. The absorption heat pump includes: a primary water supply pipeline, a primary return water pipeline, a secondary water supply pipeline, a secondary return water pipeline, a first high-pressure generator, condenser A, a throttling device A, a condenser B, a throttling device B, a first evaporator, a first absorber, a first solution heat exchanger, a first low-pressure generator, a low-temperature water-to-water heat exchanger, and a high-temperature water-to-water heat exchanger. The absorption heat pump is coupled in an orderly manner with the high-temperature water-to-water heat exchanger and the low-temperature water-to-water heat exchanger through the primary water pipeline and the secondary water pipeline to form a large temperature difference medium-high temperature coupled heat pump unit.

[0068] In the absorption heat pump cycle system, the dilute solution outlet of the first absorber is connected to the dilute solution inlet of the first solution heat exchanger. The dilute solution outlet of the first solution heat exchanger is connected to the dilute solution inlets of the first low-pressure generator and the first high-pressure generator, respectively. The concentrated solution outlets of the first high-pressure generator and the first low-pressure generator are connected to the concentrated solution inlet of the first solution heat exchanger. The concentrated solution outlet of the first solution heat exchanger is connected to the concentrated solution inlet of the first absorber. The refrigerant vapor outlet of the first high-pressure generator is connected to the refrigerant vapor inlet of condenser A. The refrigerant water outlet of condenser A is connected to the refrigerant water inlet of condenser B through throttling device A. The refrigerant vapor outlet of the first low-pressure generator is connected to the refrigerant water inlet of condenser B. The refrigerant water outlet of condenser B is connected to the refrigerant water inlet of the first evaporator through throttling device B. The refrigerant vapor outlet of the first evaporator is connected to the refrigerant vapor inlet of the first absorber.

[0069] The primary water supply pipeline is connected to the primary water inlet of the first high-pressure generator; the primary water outlet of the first high-pressure generator is connected to the primary water inlet of the first low-pressure generator; the primary water outlet of the first low-pressure generator is connected to the primary water inlet of the high-temperature water-to-water heat exchanger; the primary water outlet of the high-temperature water-to-water heat exchanger is connected to the primary water inlet of the low-temperature water-to-water heat exchanger; the primary water outlet of the low-temperature water-to-water heat exchanger is connected to the primary water inlet of the first evaporator; and the primary water outlet of the first evaporator is connected to the primary return water. The secondary return water pipeline is connected to the secondary water inlet of the low-temperature water-to-water heat exchanger; the secondary water outlet of the low-temperature water-to-water heat exchanger is connected to the secondary water inlet of the first absorber; the secondary water outlet of the first absorber is connected to the secondary water inlet of condenser B; the secondary water outlet of condenser B is connected to the secondary water inlet of condenser A; the secondary water outlet of condenser A is connected to the secondary water inlet of the high-temperature water-to-water heat exchanger; and the secondary water outlet of the high-temperature water-to-water heat exchanger is connected to the secondary water supply pipeline.

[0070] In an absorption heat pump cycle, the mixed solution of working fluid A and working fluid B is heated by a primary water supply at 130°C in the first high-pressure generator, resulting in the separation of some working fluid B vapor. The remaining concentrated solution is then heated by the first solution heat exchanger and enters the first absorber. The working fluid B vapor enters the condenser A through the refrigerant pipeline. In condenser A, working fluid B condenses and releases heat at a condensation temperature of 75°C. After passing through the throttling device A, it enters the condenser B. Simultaneously, in the first low-pressure generator, the mixed solution of working fluid A and working fluid B is heated by the primary water supply, resulting in the separation of some working fluid B vapor. The remaining concentrated solution is also heated by the first solution heat exchanger and enters the first absorber. The working fluid B vapor... The refrigerant enters condenser B through a refrigerant pipe, where it releases heat and condenses into a liquid state at a condensing temperature of 45°C. The condensed working fluid B then enters the first evaporator through a throttling device B. In the first evaporator, it absorbs heat from the primary water supply at an evaporation temperature of 8°C and then enters the first absorber. In the first absorber, it mixes with the concentrated solutions from the first high-pressure generator and the first low-pressure generator to form a dilute solution. After heat exchange in the first solution heat exchanger, it returns to the first low-pressure generator and the first high-pressure generator to complete the cycle. In the low-temperature water-to-water heat exchanger, the secondary return water exchanges heat with the primary water supply for the first time, and in the high-temperature water-to-water heat exchanger, the secondary return water exchanges heat with the primary water supply again to raise its temperature.

Claims

1. A novel medium-high temperature coupled heat pump unit, characterized in that, include: The system includes a heat source supply water pipeline, a heat source return water pipeline, a low-grade heat energy deep recovery and upgrading utilization subsystem, a half-efficiency heating absorption heat pump cycle subsystem, a heterogeneous energy flow reconstruction and coupling utilization subsystem, a primary return water pipeline, and a primary supply water pipeline. Among them, the half-efficiency heating absorption heat pump cycle subsystem is coupled with the low-grade heat energy deep recovery and upgrading utilization subsystem through a high-pressure condenser-generator, and the half-efficiency heating absorption heat pump cycle subsystem is coupled with the heterogeneous energy flow reconstruction and coupling utilization subsystem through a condenser-evaporator and an evaporator-condenser. The semi-efficiency heating absorption heat pump cycle subsystem includes: a low-pressure generator, a refrigerant pump, a high-pressure absorber, a high-temperature solution heat exchanger, a low-pressure absorber, and a low-temperature solution heat exchanger. The primary return water sequentially enters the low-pressure absorber and the high-pressure absorber, is heated to 90°C, and then enters the primary heating network as primary supply water. The heat source supply water pipeline, the driving heat source water inlet of the low-pressure generator, the driving heat source water outlet of the low-pressure generator, and the heat source return water pipeline are connected in sequence. The dilute solution outlet of the low-pressure absorber is connected to the dilute solution inlet of the low-pressure generator via the dilute solution side of the low-temperature solution heat exchanger. The dilute solution outlet of the high-pressure absorber is connected to the dilute solution inlet of the high-pressure condenser-generator via the dilute solution side of the high-temperature solution heat exchanger. The refrigerant vapor outlet of the low-pressure generator is connected to the refrigerant vapor inlet of the condenser-evaporator. The refrigerant water outlet of the condenser-evaporator is connected to the refrigerant water pump inlet. The refrigerant water pump outlet is connected to the refrigerant water inlet of the evaporator-condenser. The refrigerant vapor outlet of the evaporator-condenser is connected to the refrigerant vapor inlet of the high-pressure absorber. The refrigerant vapor outlet of the high-pressure condenser-generator is connected to the refrigerant vapor inlet of the low-pressure absorber. The concentrated solution outlet of the low-pressure generator is connected to the concentrated solution inlet of the low-pressure absorber via the concentrated solution side of the low-temperature solution heat exchanger. The refrigerant water flowing out of the low-pressure generator at 37°C sequentially enters the condenser-evaporator, refrigerant pump, and evaporator-condenser for heat exchange, reaching 66°C before entering the high-pressure absorber to release heat and condense into a liquid state. It mixes with the concentrated solution from the high-pressure condenser-generator to form a dilute solution. The refrigerant vapor flowing out of the high-pressure condenser-generator is at 59°C. The concentrated solution outlet of the high-pressure condenser-generator is connected to the concentrated solution inlet of the high-pressure absorber via the concentrated solution side of the high-temperature solution heat exchanger. In the low-grade heat energy deep recovery and upgrading utilization subsystem, the working fluid outlet of the evaporator, the low-temperature side working fluid inlet of the regenerator A, the low-temperature side working fluid outlet of the regenerator A, and the working fluid inlet of the compressor A are connected. The working fluid outlet of the compressor A, the working fluid inlet of the high-pressure condenser-generator, the working fluid outlet of the high-pressure condenser-generator, the high-temperature side working fluid inlet of the regenerator A, the high-temperature side working fluid outlet of the regenerator A, the throttle valve A, and the working fluid inlet of the evaporator are connected in sequence to form a loop. In the heterogeneous energy flow reconstruction and coupling utilization subsystem, the working fluid outlet of the condenser-evaporator is sequentially connected to the working fluid inlet on the low temperature side of the regenerator B, the working fluid outlet on the low temperature side of the regenerator B, the working fluid inlet and outlet of the compressor B, the working fluid inlet of the evaporator-condenser, the working fluid outlet of the evaporator-condenser is sequentially connected to the working fluid inlet on the high temperature side of the regenerator B, the working fluid outlet on the high temperature side of the regenerator B, and the working fluid inlet of the throttle valve B and the condenser-evaporator to form a loop.

2. The novel medium-high temperature coupled heat pump unit according to claim 1, characterized in that, The working fluid of the semi-efficiency heating absorption heat pump cycle subsystem is lithium bromide solution; the working fluid of the heterogeneous energy flow reconstruction and coupling utilization subsystem is R1234ze(E); and the working fluid of the low-grade heat energy deep recovery and upgrading utilization subsystem is carbon dioxide or R410A.

3. The novel medium-high temperature coupled heat pump unit according to claim 1, characterized in that, The semi-efficiency heating absorption heat pump cycle subsystem recovers condensation heat that would otherwise be released into the environment by coupling a high-pressure condenser-generator with a low-grade heat energy deep recovery and upgrading utilization subsystem, and by coupling the semi-efficiency heating absorption heat pump cycle subsystem with a condenser-evaporator, an evaporator-condenser, and a heterogeneous energy flow reconstruction and coupling utilization subsystem. At the same time, the condensation heat is upgraded by consuming electrical energy in the low-grade heat energy deep recovery and upgrading utilization subsystem and the heterogeneous energy flow reconstruction and coupling utilization subsystem, and is directly used to drive the working fluid water vaporization of the evaporator-condenser. This is suitable for heating heat pump cycles that use low-grade heat energy to achieve high-temperature hot water production in large temperature difference heat exchange production. The semi-efficiency heating absorption heat pump cycle subsystem is coupled with the low-grade heat energy deep recovery and upgrading utilization subsystem through a high-pressure condenser-generator as follows: The high-pressure condenser-generator serves as a condenser in the low-grade heat energy deep recovery and upgrading subsystem. The semi-efficiency heating absorption heat pump cycle subsystem is coupled to the heterogeneous energy flow reconstruction and coupling utilization subsystem through the condenser-evaporator, evaporator-condenser, and the heterogeneous energy flow reconstruction and coupling utilization subsystem as follows: The condenser-evaporator functions as a condenser in the half-efficiency heating absorption heat pump cycle subsystem, and also as an evaporator in the heterogeneous energy flow reconstruction and coupling utilization subsystem. The evaporator-condenser functions as an evaporator in the semi-efficiency heating absorption heat pump cycle subsystem, and also as a condenser in the heterogeneous energy flow reconstruction and coupling utilization subsystem.

4. The novel medium-high temperature coupled heat pump unit according to claim 2, characterized in that, The low-pressure generator's drive heat source water outlet is connected to the heat source return water pipeline via the low-temperature heat source water side of the evaporator.

5. The novel medium-high temperature coupled heat pump unit according to claim 4, characterized in that, The heat source supply water and the heat source return water are respectively low-temperature waste heat supply water at 45℃ and low-temperature waste heat return water at 30℃.

6. The novel medium-high temperature coupled heat pump unit according to claim 4, characterized in that, A three-way valve VS1, a valve V2, and a three-way valve VS3 are sequentially installed between the low-pressure generator driving heat source water outlet and the evaporator driving heat source water inlet. A three-way valve VS4, a valve V3, and a three-way valve VS2 are sequentially installed between the evaporator low-temperature heat source outlet and the heat source return water pipeline. The third path of the three-way valve VS1 and the third path of the three-way valve VS2 are connected by the valve V1. The third path of the three-way valve VS3 is connected to the shallow geothermal water supply pipeline through the valve V4. The third path of the three-way valve VS4 is connected to the shallow geothermal return water pipeline through the valve V5. The heat source supply water and heat source return water are low-temperature waste heat supply water at 45℃ and low-temperature waste heat return water at 35℃, respectively; the temperatures of shallow geothermal supply water and shallow geothermal return water are 15℃ and 10℃, respectively.

7. The novel medium-high temperature coupled heat pump unit according to any one of claims 1 to 6, characterized in that, The primary return water pipeline is connected in sequence to the cold side of the double-effect absorption heat pump, the cold side of the heat source water-to-water heat exchanger, and the primary return water pipeline of the heat source station; the primary supply water pipeline is connected in sequence to the cold side of the steam-to-water heat exchanger and the primary supply water pipeline of the heat source station. The hot side of the heat source water-to-water heat exchanger is connected to the third low-temperature waste heat supply and return water pipeline; the hot side of the double-effect absorption heat pump is connected to the second low-temperature waste heat supply and return water pipeline; and the high-temperature side of the steam-to-water heat exchanger is connected to the power plant's low-pressure extraction steam supply and return pipeline. The primary water supply from the heat source station, at 130°C, is cooled to 10°C in a high-temperature coupled heat pump with a large temperature difference at the primary energy station. It then returns to the heat source station as primary return water via the primary heating network, where it is reheated, and the cycle continues. The secondary water supply from the primary energy station, at 90°C, first enters the low-temperature, large-temperature-difference heat exchanger at the secondary energy station via the secondary heating network, where it is cooled to 25°C. It then returns to the primary energy station as secondary return water via the secondary heating network, where it is reheated, and the cycle continues. In the secondary energy station, the tertiary return water, at 35°C, is heated to 45°C by a low-temperature, large-temperature-difference heat exchanger, and then distributed to heat users as tertiary supply water.

8. The novel medium-high temperature coupled heat pump unit according to claim 7, characterized in that, The large temperature difference medium-high temperature coupled heat pump unit includes: a high-temperature water-to-water heat exchanger, a low-temperature water-to-water heat exchanger, a primary water supply pipeline, a primary water return pipeline, a secondary water supply pipeline, a secondary water return pipeline, a first high-pressure generator, a condenser A, a throttling device A, a condenser B, a throttling device B, a first evaporator, a first absorber, a first solution heat exchanger, a first low-pressure generator, a low-temperature water-to-water heat exchanger, and a high-temperature water-to-water heat exchanger; the absorption heat pump is orderly coupled with the high-temperature water-to-water heat exchanger and the low-temperature water-to-water heat exchanger through the primary water pipeline and the secondary water pipeline, so as to realize heat flow reconstruction and orderly cascade efficient utilization of energy; The dilute solution outlet of the first absorber is connected to the dilute solution inlet of the first solution heat exchanger. The dilute solution outlet of the first solution heat exchanger is connected to the dilute solution inlets of the first low-pressure generator and the first high-pressure generator, respectively. The concentrated solution outlets of the first high-pressure generator and the first low-pressure generator are connected to the concentrated solution inlet of the first solution heat exchanger. The concentrated solution outlet of the first solution heat exchanger is connected to the concentrated solution inlet of the first absorber. The refrigerant vapor outlet of the first high-pressure generator is connected to the refrigerant vapor inlet of condenser A. The refrigerant water outlet of condenser A is connected to the refrigerant water inlet of condenser B through throttling device A. The refrigerant vapor outlet of the first low-pressure generator is connected to the refrigerant water inlet of condenser B. The refrigerant water outlet of condenser B is connected to the refrigerant water inlet of the first evaporator through throttling device B. The refrigerant vapor outlet of the first evaporator is connected to the refrigerant vapor inlet of the first absorber. The primary water supply pipeline is connected to the primary water inlet of the first high-pressure generator; the primary water outlet of the first high-pressure generator is connected to the primary water inlet of the first low-pressure generator; the primary water outlet of the first low-pressure generator is connected to the primary water inlet of the high-temperature water-to-water heat exchanger; the primary water outlet of the high-temperature water-to-water heat exchanger is connected to the primary water inlet of the low-temperature water-to-water heat exchanger; the primary water outlet of the low-temperature water-to-water heat exchanger is connected to the primary water inlet of the first evaporator; and the primary water outlet of the first evaporator is connected to the primary return water. The secondary return water pipeline is connected to the secondary water inlet of the low-temperature water-to-water heat exchanger; the secondary water outlet of the low-temperature water-to-water heat exchanger is connected to the secondary water inlet of the first absorber; the secondary water outlet of the first absorber is connected to the secondary water inlet of condenser B; the secondary water outlet of condenser B is connected to the secondary water inlet of condenser A; the secondary water outlet of condenser A is connected to the secondary water inlet of the high-temperature water-to-water heat exchanger; and the secondary water outlet of the high-temperature water-to-water heat exchanger is connected to the secondary water supply pipeline.

9. A method for operating a novel medium-high temperature coupled heat pump unit as described in claim 1, characterized in that, include: Single heat source operation mode and multi-heat source coordinated operation mode; The single heat source operation mode is as follows: In the semi-efficiency heating type absorption heat pump cycle subsystem, the mixed solution of working fluid A and working fluid B is heated by the low-temperature waste heat supply water of the 45℃ driving heat source in the low-pressure generator, and a portion of working fluid B vapor is generated. The working fluid B vapor enters the condenser-evaporator through the refrigerant channel. After the working fluid B condenses and releases heat in the condenser-evaporator with a condensation temperature of 12℃, it is pressurized by the refrigerant pump and enters the evaporator-condenser. After absorbing heat and evaporating in the evaporator-condenser with an evaporation temperature of 66℃, it enters the high-pressure absorber through the refrigerant channel. At the same time, in the high-pressure condenser-generator, the mixed solution of working fluid A and working fluid B is heated at a generation temperature of 59℃, and a portion of working fluid B vapor is generated. The working fluid B vapor enters the low-pressure absorber through the refrigerant channel. The remaining concentrated solution in the low-pressure generator enters the low-pressure absorber after heat exchange in the low-temperature solution heat exchanger. There, it absorbs refrigerant vapor from the high-pressure condenser-generator, becoming a dilute solution. After heat exchange in the low-temperature solution heat exchanger, it re-enters the low-pressure generator to complete the low-pressure solution cycle. Similarly, the remaining concentrated solution in the high-pressure condenser-generator enters the high-pressure absorber after heat exchange in the high-temperature solution heat exchanger. There, it absorbs refrigerant vapor from the evaporator, becoming a dilute solution. After heat exchange in the high-temperature solution heat exchanger, it re-enters the high-pressure condenser-generator to complete the high-pressure solution cycle. In the low-grade heat energy deep recovery and upgrading subsystem, the low-temperature waste heat circulating water from the low-pressure generator outlet enters the evaporator as a low-temperature heat source and further releases heat and cools to 30°C before being discharged. The working fluid C first absorbs heat at an evaporation temperature of 28°C, becoming working fluid C vapor. Then, it enters the compressor A through the regenerator A and is pressurized therein. Secondly, it enters the high-pressure condenser-generator and is condensed at a condensing temperature of 63°C; finally, it passes through the regenerator A and the throttling valve A in sequence and enters the evaporator to complete a single working fluid C cycle; in the heterogeneous energy flow reconstruction and coupling utilization subsystem, the working fluid D first absorbs heat and evaporates into working fluid D vapor at an evaporation temperature of 10°C in the condenser-evaporator; secondly, it enters the compressor B through the regenerator B, is pressurized in the compressor B, and then enters the evaporator-condenser; then, the working fluid D vapor is condensed at a condensing temperature of 68°C in the evaporator-condenser; finally, it passes through the regenerator B and the throttling valve B in sequence and enters the condenser-evaporator to complete a single working fluid D cycle; The multi-heat source operation mode is as follows: 45℃ low-temperature waste heat supply water enters the hot side of the low-pressure generator to drive the absorption heat pump to run and discharge 35℃ low-temperature waste heat return water. 15℃ shallow geothermal supply water enters the hot side of the evaporator to release heat and then discharges 10℃ shallow geothermal return water through the pipeline. At the same time, shallow geothermal and low-temperature waste heat are utilized. In the semi-efficiency heating absorption heat pump cycle subsystem, the mixed solution of working fluid A and working fluid B is heated by low-temperature waste heat water supplied by a 45°C driving heat source in the low-pressure generator, generating some working fluid B vapor. The working fluid B vapor enters the condenser-evaporator through the refrigerant channel. After condensing and releasing heat in the condenser-evaporator at a condensation temperature of 12°C, working fluid B is pressurized by the refrigerant pump and enters the evaporator-condenser. After absorbing heat and evaporating in the evaporator-condenser at an evaporation temperature of 66°C, it enters the high-pressure absorber through the refrigerant channel. At the same time, in the high-pressure condenser-generator, the mixed solution of working fluid A and working fluid B is heated at a generation temperature of 59°C, generating some working fluid B vapor. The working fluid B vapor enters the low-pressure absorber through the refrigerant channel. The remaining concentrated solution in the low-pressure generator enters the low-pressure absorber after heat exchange in the low-temperature solution heat exchanger. There, it absorbs refrigerant vapor from the high-pressure condenser-generator, becoming a dilute solution. After heat exchange in the low-temperature solution heat exchanger, it re-enters the low-pressure generator to complete the low-pressure solution cycle. Similarly, the remaining concentrated solution in the high-pressure condenser-generator enters the high-pressure absorber after heat exchange in the high-temperature solution heat exchanger. There, it absorbs refrigerant vapor from the evaporator, becoming a dilute solution. After heat exchange in the high-temperature solution heat exchanger, it re-enters the high-pressure condenser-generator to complete the high-pressure solution cycle. In the low-grade heat energy deep recovery and upgrading subsystem, shallow geothermal water, as a low-temperature heat source, enters the evaporator to release heat and cool to 10°C before being discharged. The working fluid C first absorbs heat at an evaporation temperature of 8°C, becoming working fluid C vapor. Then, it enters the compressor A through the regenerator A and is pressurized therein. Secondly, it enters the high-pressure condenser-generator and is condensed at a condensing temperature of 63°C. Finally, it passes through the regenerator A and the throttling valve A in sequence and enters the evaporator, thus completing a single working fluid C cycle. In the heterogeneous energy flow reconstruction and coupling utilization subsystem, the working fluid D first absorbs heat and evaporates into working fluid D vapor at an evaporation temperature of 10°C in the condenser-evaporator. Next, it enters the compressor B through the regenerator B, is pressurized in the compressor B, and then enters the evaporator-condenser. Then, the working fluid D vapor is condensed at a condensation temperature of 68°C in the evaporator-condenser. Finally, it passes through the regenerator B and the throttling valve B in sequence and enters the condenser-evaporator, completing a single working fluid D cycle.

10. The operating method of the novel medium-high temperature coupled heat pump unit according to claim 9, characterized in that, Working medium A is lithium bromide, working medium B is water; working medium C is carbon dioxide or R410A; working medium D is R1234ze(E).

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