A heat source heat pump system for large temperature difference and long distance heating

Abstract

The present invention discloses a heat source heat pump system for large temperature difference and long distance heating, which belongs to the field of waste heat recovery and utilization, including an organic Rankine cycle device, a vapor compression heat pump, an intermediate heat exchanger, a primary heat network flow path, a medium-temperature heat source flow path and a power device; the organic Rankine cycle device uses the medium-grade heat of the medium-temperature heat source to drive the vapor compression heat pump to operate, and uses the waste heat to heat the water from the primary heat network; the power device supplements the driving force of the vapor compression heat pump; the intermediate heat exchanger uses the medium-grade heat of the medium-temperature heat source to directly heat the water from the primary heat network; the vapor compression heat pump absorbs the medium-grade heat of the medium-temperature heat source to generate high-grade heat to heat the water from the primary heat network to a specified temperature. The heat source heat pump system of the present invention effectively improves the waste heat recovery conversion rate, avoids the problem of unstable performance of the absorption heat pump, and is more suitable for large temperature difference and long distance heating.

Description

Technical Field

[0001] The invention belongs to the field of waste heat recovery and utilization, and specifically relates to a heat source heat pump system for long-distance heating with a large temperature difference. Background Art

[0002] The regional centralized heating system consists of factories, heat networks (primary heat network, secondary heat network), heat source stations and users. The factory and the heat source station are connected to the primary heat network, and the heat source station and the user are connected to the secondary heat network. The factory supplies the high-temperature fluid in the primary heat network to the heat source station for heat exchange, and the low-temperature fluid returns to the factory after cooling. There is a surplus of medium-temperature waste heat in the industrial field. If the low temperature is directly heated and returned to the high temperature, the gradient utilization of heat cannot be achieved. The patent application with the publication number CN114251709A proposes a heat source station solution consisting of an absorption heat pump and a heat exchanger, which uses the second type of absorption heat pump technology to recover the medium-temperature waste heat in the industrial field to produce steam or high-temperature hot water. However, the absorption heat pump of this method is in a negative pressure environment and is prone to air leakage and non-condensable gas, which causes the deterioration of the performance of the absorption heat pump. At the same time, due to the constant phase change temperature of the refrigerant in the condenser and evaporator in the absorption heat pump, the heat exchange temperature difference is poor in uniformity during the heat exchange process, and the heat exchange efficiency is low. The heat source station solution still needs to be further optimized. Summary of the invention

[0003] The purpose of the present invention is to address the problems in the above-mentioned prior art and provide a heat source heat pump system for long-distance heating with large temperature differences, which can improve the waste heat recovery conversion rate, avoid the unstable performance of the absorption heat pump, and at the same time improve the unevenness of the heat exchange temperature difference and increase the heat exchange efficiency.

[0004] In order to achieve the above object, the present invention has the following technical solutions:

[0005] A heat source heat pump system for long-distance heating with a large temperature difference comprises an organic Rankine cycle device, a vapor compression heat pump, an intermediate heat exchanger, a primary heating network flow path, a medium-temperature heat source flow path and a power device; the organic Rankine cycle device utilizes the medium-grade heat of the medium-temperature heat source to drive the vapor compression heat pump to operate, and utilizes the waste heat to heat the water from the primary heating network; the power device supplements the driving force of the vapor compression heat pump; the intermediate heat exchanger utilizes the medium-grade heat of the medium-temperature heat source to directly heat the water from the primary heating network; the vapor compression heat pump absorbs the medium-grade heat of the medium-temperature heat source to generate high-grade heat to heat the water from the primary heating network to a specified temperature.

[0006] As a preferred solution, the organic Rankine cycle device includes an expander, a condensing heat exchanger, a working fluid pump, an evaporating heat exchanger connected in sequence through pipelines, and an ORC working fluid flowing in the pipelines; the vapor compression heat pump includes a compressor, a condenser, an expansion valve, an evaporator, and a heat pump working fluid flowing in the pipelines; the medium-temperature heat source water supply is divided into three paths connected in parallel through the evaporating heat exchanger, the intermediate heat exchanger, and the evaporator to release heat, and the organic Rankine cycle device absorbs heat from the medium-temperature heat source water supply to generate superheated gas The ORC working fluid in the exhausted state enters the expander to perform work, providing power for the compressor of the vapor compression heat pump, and at the same time, the water from the primary heating network absorbs the waste heat of the ORC working fluid in the exhausted state; the water from the primary heating network exchanges heat with the medium-temperature heat source water supply in the intermediate heat exchanger to increase the temperature; the vapor compression heat pump absorbs the medium-grade heat of the medium-temperature heat source water supply to generate high-grade heat to heat the water from the primary heating network to a specified temperature; the water from the primary heating network passes through the condensing heat exchanger, the heat exchanger, and the condenser in sequence, absorbing heat in the temperature range from low to high until it reaches the specified temperature.

[0007] As a preferred solution, the power device is connected between the expander and the compressor, and the power device includes a motor, a first clutch, a second clutch and a transmission; the organic Rankine cycle device also includes an expander output shaft, and the vapor compression heat pump also includes a compressor drive shaft, the expander output shaft is connected to the expander, and the compressor drive shaft is connected to the compressor; the expander output shaft is connected to the compressor drive shaft through the transmission and the first clutch, and the motor is connected to the compressor drive shaft through the second clutch, the first clutch and the second clutch are both connected or disconnected from the compressor drive shaft, and the expander and the motor transmit power to the compressor simultaneously or individually.

[0008] As a preferred solution, a three-way valve capable of bypassing the condensing heat exchanger is provided in the primary heat network flow path, so that the water from the primary heat network does not pass through the organic Rankine cycle device but only passes through the intermediate heat exchanger and the condenser in sequence; a valve is provided in the medium-temperature heat source flow path, and the valve is used to control whether the medium-temperature heat source water supply passes through the evaporative heat exchanger.

[0009] As a preferred solution, when the water supply temperature of the medium-temperature heat source is greater than 75°C, the first clutch connects the expander output shaft and the compressor drive shaft, and the second clutch disconnects the motor and the compressor drive shaft, the motor does not start, and the compressor is completely driven by the expander;

[0010] When the water supply temperature of the medium-temperature heat source is between 65°C and 75°C, the first clutch and the second clutch are connected to the expander output shaft, the motor and the compressor drive shaft respectively, the motor is started, and the compressor is driven by the expander and the motor;

[0011] When the water supply temperature of the primary heating network is lower than 65℃, the first clutch disconnects the expander output shaft and the compressor drive shaft, the second clutch connects the motor and the compressor drive shaft, the motor starts, the compressor is completely driven by the motor, the three-way valve bypasses the condensing heat exchanger, and the valve prohibits the medium-temperature heat source water supply from passing through the evaporating heat exchanger.

[0012] As a preferred solution, a regenerative heat exchanger is provided inside the organic Rankine cycle device, and the regenerative heat exchanger is provided between the pipelines connecting the expander and the evaporative heat exchanger and the pipelines connecting the condensing heat exchanger and the working fluid pump; a regenerative heat exchanger is provided inside the vapor compression heat pump, and the regenerative heat exchanger is provided between the pipelines connecting the compressor and the condenser and the pipelines connecting the expansion valve and the evaporator.

[0013] As a preferred solution, the ORC working fluid and the heat pump working fluid are both non-azeotropic mixed working fluids; the bubble point temperature range of the ORC working fluid at standard pressure is 225K~300K, and the dew point temperature range is 235K~310K; the bubble point temperature range of the heat pump working fluid at standard pressure is 245K~320K, and the dew point temperature range is 265K~340K.

[0014] As a preferred solution, the expander has a built-in double cylinder, which is composed of a first expander with a larger cylinder volume and a second expander with a smaller cylinder volume. The condensing heat exchanger is composed of a first condensing heat exchanger and a second condensing heat exchanger. The water from the primary heat network passes through the first condensing heat exchanger and the second condensing heat exchanger in sequence. The ORC working fluid in the first condensing heat exchanger and the second condensing heat exchanger comes from the first expander and the second expander respectively, and is pumped by the first working fluid pump and the second working fluid pump respectively. The average temperature and pressure of the ORC working fluid inside the first condensing heat exchanger are lower than those of the second condensing heat exchanger.

[0015] As a preferred solution, the compressor has a built-in dual cylinder, consisting of a first compressor with a lower exhaust pressure and a second compressor with a higher exhaust pressure. The condenser consists of a first condenser and a second condenser. The water from the primary heat network passes through the first condenser and the second condenser in turn. The heat pump working fluid in the first condenser and the second condenser comes from the first compressor and the second compressor respectively. The average temperature and pressure of the heat pump working fluid in the first condenser are lower than those in the second condenser.

[0016] As a preferred solution, the primary heat network water outlet is provided with an auxiliary heating device. When the organic Rankine cycle device and the vapor compression heat pump are not sufficient to heat the primary heat network water to a specified temperature, the auxiliary heating device uses high-grade heat for supplementary heating.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] The combination of an organic Rankine cycle device and a vapor compression heat pump is adopted to avoid the problem of the absorption heat pump in the prior art that the performance of the absorption heat pump is easily deteriorated due to the internal negative pressure environment. At the same time, due to the constant phase change temperature of the refrigerant in the condenser and the evaporator in the absorption heat pump, the heat exchange temperature difference uniformity is poor during the heat exchange process, and the heat exchange efficiency is low. The organic Rankine cycle device in the heat source heat pump system of the present invention uses the medium-grade heat of the medium-temperature heat source water supply to drive the vapor compression heat pump to operate, and uses the waste heat to heat the water from the primary heating network. The power device supplements the driving force of the compressor in the heat pump, and the intermediate heat exchanger uses the medium-grade heat of the medium-temperature heat source water supply to directly heat the water from the primary heating network. The vapor compression heat pump absorbs the medium-grade heat of the medium-temperature heat source water supply to generate high-grade heat to heat the water from the primary heating network to a specified temperature, which effectively improves the waste heat recovery conversion rate, avoids the problem of unstable performance of the absorption heat pump, and is more suitable for large temperature difference and long-distance heating.

[0019] Furthermore, the ORC working fluid in the organic Rankine cycle device of the present invention and the heat pump working fluid in the vapor compression heat pump are all non-azeotropic mixed working fluids, which can reduce the non-uniformity of the heat exchange temperature difference between the evaporation heat exchanger and the evaporator, the condensation heat exchanger and the condenser and the primary heat network water supply and the secondary heat network water. All the heat exchangers in the heat source heat pump system of the present invention are arranged in a countercurrent heat exchange flow, which improves the non-uniformity of the heat exchange temperature difference and enhances the heat exchange efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 A schematic diagram of the structure of a heat source heat pump system for large temperature difference and long distance heating according to the first embodiment of the present invention;

[0022] Figure 2 A temperature-heat exchange diagram of internal heat exchange in a heat source heat pump system for large temperature difference and long distance heating according to the first embodiment of the present invention;

[0023] Figure 3 A schematic diagram of the structure of a heat source heat pump system for large temperature difference and long distance heating according to a second embodiment of the present invention;

[0024] Figure 4 A temperature-heat exchange diagram of internal heat exchange in a heat source heat pump system for large temperature difference and long distance heating according to the second embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, ordinary technicians in this field can also obtain other embodiments without making creative work.

[0026] Figure 1 , Figure 2 Describes an embodiment of the present invention, such as Figure 1 As shown, the heat source heat pump system for large temperature difference and long distance heating of the present invention comprises an organic Rankine cycle device, a vapor compression heat pump, an intermediate heat exchanger 300, a primary heat network flow path 400, a medium temperature heat source flow path 500, a power device and an auxiliary heating device 700, wherein the organic Rankine cycle device comprises an expander 101, a condensing heat exchanger 102, a working fluid pump 103, an evaporating heat exchanger 104, an ORC working fluid flowing in the pipeline, a heat recovery heat exchanger 105 located between the expander 101, the evaporating heat exchanger 104 and the condensing heat exchanger 102, the working fluid pump 103, and a heat recovery heat exchanger 105 connected to the expander 101. The expander output shaft 107 is connected; the vapor compression heat pump includes a compressor 201, a condenser 202, an expansion valve 203, and an evaporator 204 which are connected in sequence through pipelines, a heat pump working fluid flowing in the pipeline, a regenerator 205 located between the compressor 201, the condenser 202 and the expansion valve 203, the evaporator 204, and a compressor drive shaft 207 connected to the compressor 201; a three-way valve 401 is provided in the primary heat network flow path 400, and a valve 501 is provided in the medium-temperature heat source flow path 500; the power unit 600 includes a motor 601, a first clutch 611, a second clutch 612, and a transmission 621.

[0027] In the primary heat network flow path 400, the primary heat network water from the user passes through the condensing heat exchanger 102, the heat exchanger 300, and the condenser 202 in sequence, absorbing heat in the temperature range from low to high until the specified temperature is reached; in the medium-temperature heat source flow path 500, the medium-temperature heat source water supply is divided into three parallel routes through the evaporative heat exchanger 104, the intermediate heat exchanger 300 and the evaporator 204 to release heat.

[0028] In the organic Rankine cycle device 100, the ORC working medium absorbs heat from the evaporative heat exchanger 104, and the temperature rises to the superheated gas state, and then enters the expander 101 to expand and do work. The expander 101 transmits power to the compressor 201 through the expander output shaft 107, the transmission 621, the first clutch 611, and the compressor drive shaft 207. The exhaust steam ORC working medium that has done work flows through the regenerative heat exchanger 105 to exchange heat with the liquid ORC working medium. The exhaust steam ORC working medium releases heat and cools down, while the liquid ORC working medium absorbs heat and heats up. The cooled exhaust steam ORC working medium flows through the condensing heat exchanger 102 to exchange heat with the water from the primary heating network, and the exhaust steam ORC working medium is condensed into liquid ORC working medium. The liquid ORC working medium is driven and pressurized by the working medium pump 103, flows through the regenerative heat exchanger 105, absorbs heat and heats up, and then enters the evaporative heat exchanger 104. This process is repeated.

[0029] In a vapor compression heat pump, the heat pump working fluid absorbs heat from the evaporator 204, and the temperature rises and the phase changes into a gaseous state or a gas-liquid two-phase heat pump working fluid; then it flows through the regenerator 205 to exchange heat with the liquid heat pump working fluid, and the gaseous state or the gas-liquid two-phase heat pump working fluid absorbs heat and rises in temperature to become a superheated gaseous heat pump working fluid, and the liquid heat pump working fluid releases heat and cools down to become a supercooled liquid heat pump working fluid; after the superheated gaseous heat pump working fluid enters the compressor 201, it is pressurized and heated to become a high-temperature and high-pressure heat pump working fluid; the high-temperature and high-pressure heat pump working fluid flows through the condenser 202 to exchange heat with the water from the primary heating network, and the high-temperature and high-pressure heat pump working fluid releases heat and condenses into a liquid heat pump working fluid; the liquid heat pump working fluid flows through the regenerator 205 and is supercooled before entering the evaporator 204, and this process is repeated.

[0030] When the water supply temperature of the medium-temperature heat source is greater than 75°C, the first clutch 611 connects the expander output shaft 107 and the compressor drive shaft 207, and the second clutch 612 disconnects the motor 601 and the compressor drive shaft 207, the motor 601 does not start, and the compressor 201 is completely driven by the expander 101;

[0031] When the medium-temperature heat source water supply temperature is between 65°C and 75°C, the first clutch 611 and the second clutch 612 are connected to the expander output shaft 107, the motor 601 and the compressor drive shaft 207 respectively, the motor 601 is started, and the compressor 201 is driven by the expander 101 and the motor 601;

[0032] When the water supply temperature of the primary heating network is lower than 65°C, the motor 601 starts, the first clutch 611 disconnects the expander output shaft 107 and the compressor drive shaft 207, the second clutch 612 connects the motor 601 and the compressor drive shaft 207, the compressor 201 is completely driven by the motor 601, the three-way valve 401 bypasses the condensing heat exchanger 102, and the valve 501 prohibits the medium-temperature heat source water supply from passing through the evaporating heat exchanger 104.

[0033] When the organic Rankine cycle device and the vapor compression heat pump are not sufficient to heat the water from the primary heating network to a specified temperature, the auxiliary heating device 700 uses high-grade heat for further heating.

[0034] The ORC working fluid and heat pump working fluid in the heat source heat pump system of the present invention are both non-azeotropic mixed working fluids to reduce the non-uniformity of the heat exchange temperature difference in the heat exchanger. All heat exchangers in the system are arranged in a countercurrent heat exchange flow to enhance the heat exchange efficiency.

[0035] like Figure 2 As shown, the temperature-heat exchange rate diagram illustrates the heat exchange conditions inside the heat source heat pump system of the present invention. It can be seen that after adopting the flow arrangement of non-azeotropic mixed working fluid and countercurrent heat exchange, the heat exchange curve forms a plurality of approximate "parallelograms", while the heat exchange curve of the heat source station system based on absorption heat pump is a "triangle" in the phase change heat exchange curve in the evaporator and condenser, and the phase change temperature on the working fluid side remains unchanged, and the heat exchange temperature difference is uneven. The heat exchange temperature difference uniformity of the heat source heat pump system of the present invention is better than that of the heat source station system based on absorption heat pump.

[0036] The temperature change of the water from the primary heat network through the heat exchanger is significantly greater than that of the water supplied by the medium-temperature heat source. Therefore, the non-azeotropic mixed working fluid cannot simultaneously match the heat exchange temperature difference on both sides. If a working fluid with a larger temperature glide is selected, the excessive condensation temperature glide will affect the operating efficiency of the ORC and heat pump system. Therefore, the heat exchanger on the primary heat network side with a large temperature change can be partitioned for heat exchange to match the heat exchange temperature difference, that is, embodiment 2.

[0037] Figure 3 , Figure 4 Another embodiment of the present invention is described as follows: Figure 3 As shown, the heat source heat pump system for large temperature difference and long distance heating of the present invention is consistent with the first embodiment except for the expander 101, the condensing heat exchanger 102, the working fluid pump 103 and its pipeline connection, the compressor 201, the condenser 202 and its pipeline connection.

[0038] The expander 101 has dual cylinders built in, which can be regarded as a first expander 101-1 with a larger cylinder volume and a second expander 101-2 with a smaller cylinder volume. The condensing heat exchanger 102 is divided into two parts. The water from the primary heat network passes through the first condensing heat exchanger 102-1 and the second condensing heat exchanger 102-2 in turn. The ORC working fluid therein comes from the first expander 101-1 and the second expander 101-2, and is pumped by the first working fluid pump 103-1 and the second working fluid pump 103-2, respectively. The average temperature and pressure of the ORC working fluid inside the first condensing heat exchanger 102-1 are lower than those of the second condensing heat exchanger 102-2.

[0039] The compressor 201 has two cylinders built in, which can be regarded as a first compressor 201-1 with lower exhaust pressure and a second compressor 201-2 with higher exhaust pressure. The condenser 202 is divided into two parts. The water from the primary heat network passes through the first condenser 202-1 and the second condenser 202-2 in turn. The heat pump working fluid therein comes from the first compressor 201-1 and the second compressor 201-2 respectively. The average temperature and pressure of the heat pump working fluid inside the first condenser 202-1 are lower than those of the second condenser 202-2.

[0040] like Figure 4 As shown, due to the partitioning of the heat exchanger, the working fluid flow rate in each evaporating heat exchanger 104 and evaporator 204 is greater than the flow rate in the corresponding condensing heat exchanger 102 and condenser 202. Therefore, the slope of the evaporating side in the temperature-heat exchange diagram is smaller than the slope of the condensing side. Compared with Example 1, the heat exchange temperature difference can achieve higher uniformity, thereby improving the heat exchange efficiency.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and substitutions, and these modifications and substitutions will also fall within the scope of protection covered by the claims.

Claims

1. A heat source heat pump system for large temperature difference and long distance heating, characterized in that: The invention comprises an organic Rankine cycle device, a steam compression heat pump, an intermediate heat exchanger (300), a primary heat network flow path (400), a medium-temperature heat source flow path (500), and a power device; the organic Rankine cycle device utilizes the medium-grade heat of the water supplied by the medium-temperature heat source to drive the steam compression heat pump to operate, and utilizes the waste heat to heat the water supplied by the primary heat network; the power device supplements the driving force of the steam compression heat pump; the intermediate heat exchanger (300) utilizes the medium-grade heat of the water supplied by the medium-temperature heat source to directly heat the water supplied by the primary heat network; the steam compression heat pump absorbs the medium-grade heat of the water supplied by the medium-temperature heat source to generate high-grade heat to heat the water supplied by the primary heat network to a specified temperature; The organic Rankine cycle device comprises an expander (101), a condensing heat exchanger (102), a working fluid pump (103), an evaporating heat exchanger (104) connected in sequence through a pipeline, and an ORC working fluid flowing in the pipeline; the vapor compression heat pump comprises a compressor (201), a condenser (202), an expansion valve (203), an evaporator (204) connected in sequence through a pipeline, and a heat pump working fluid flowing in the pipeline; the medium-temperature heat source water supply is divided into three paths connected in parallel through an evaporating heat exchanger (104), an intermediate heat exchanger (300), and an evaporator (204) to release heat, and the organic Rankine cycle device absorbs heat from the medium-temperature heat source water supply The amount of ORC working fluid in a superheated gas state is generated, and the ORC working fluid enters the expander (101) to perform work, thereby providing power for the compressor (201) of the vapor compression heat pump. At the same time, the primary heat network water absorbs the waste heat of the ORC working fluid in a steam-deficient state; the primary heat network water exchanges heat with the medium-temperature heat source water supply in the intermediate heat exchanger (300) to increase the temperature; the vapor compression heat pump absorbs the medium-grade heat of the medium-temperature heat source water supply to generate high-grade heat to heat the primary heat network water to a specified temperature; the primary heat network water passes through the condensing heat exchanger (102), the heat exchanger (300), and the condenser (202) in sequence, and absorbs heat in the temperature range from low to high until the specified temperature is reached; The power device is connected between the expander (101) and the compressor (201), and comprises a motor (601), a first clutch (611), a second clutch (612) and a transmission (621); the organic Rankine cycle device further comprises an expander output shaft (107), and the vapor compression heat pump (200) further comprises a compressor drive shaft (207); the expander output shaft (107) is connected to the expander (101), and the compressor drive shaft (207) is connected to the compressor (201); the expander output shaft (107) is connected to the compressor drive shaft (207) through the transmission (621) and the first clutch (611), the motor (601) is connected to the compressor drive shaft (207) through the second clutch (612), the first clutch (611) and the second clutch (612) are both connected to or disconnected from the compressor drive shaft (207), and the expander (101) and the motor (601) transmit power to the compressor (201) simultaneously or individually.

2. The heat source heat pump system for large temperature difference and long distance heating according to claim 1, characterized in that: The primary heat network flow path (400) is provided with a three-way valve (401) capable of bypassing the condensing heat exchanger (102), so that the water from the primary heat network does not pass through the organic Rankine cycle device but only passes through the intermediate heat exchanger (300) and the condenser (202) in sequence; the medium-temperature heat source flow path (500) is provided with a valve (501), and the valve (501) is used to control whether the water supplied by the medium-temperature heat source passes through the evaporating heat exchanger (104).

3. The heat source heat pump system for large temperature difference and long distance heating according to claim 2 is characterized in that: When the water supply temperature of the medium-temperature heat source is greater than 75° C., the first clutch (611) connects the expander output shaft (107) and the compressor drive shaft (207), and the second clutch (612) disconnects the motor (601) and the compressor drive shaft (207), the motor (601) does not start, and the compressor (201) is completely driven by the expander (101); When the water supply temperature of the medium-temperature heat source is between 65° C. and 75° C., the first clutch (611) and the second clutch (612) are respectively connected to the expander output shaft (107), the motor (601) and the compressor drive shaft (207), the motor (601) is started, and the compressor (201) is driven by the expander (101) and the motor (601); When the water supply temperature of the primary heating network is lower than 65° C., the first clutch (611) disconnects the expander output shaft (107) and the compressor drive shaft (207), the second clutch (612) connects the motor (601) and the compressor drive shaft (207), the motor (601) starts, the compressor (201) is completely driven by the motor (601), the three-way valve (401) bypasses the condensing heat exchanger (102), and the valve (501) prohibits the medium-temperature heat source from supplying water through the evaporating heat exchanger (104).

4. The heat source heat pump system for large temperature difference and long distance heating according to claim 1, characterized in that: A regenerative heat exchanger (105) is provided inside the organic Rankine cycle device (100), and the regenerative heat exchanger (105) is provided between the pipelines connecting the expander (101) and the evaporating heat exchanger (104) and the pipelines connecting the condensing heat exchanger (102) and the working fluid pump (103); a regenerative heat exchanger (205) is provided inside the vapor compression heat pump, and the regenerative heat exchanger (205) is provided between the pipelines connecting the compressor (201) and the condenser (202) and the pipelines connecting the expansion valve (203) and the evaporator (204).

5. The heat source heat pump system for large temperature difference and long distance heating according to claim 1, characterized in that: The ORC working fluid and the heat pump working fluid are both non-azeotropic mixed working fluids; the bubble point temperature range of the ORC working fluid at standard pressure is 225K~300K, and the dew point temperature range is 235K~310K; the bubble point temperature range of the heat pump working fluid at standard pressure is 245K~320K, and the dew point temperature range is 265K~340K.

6. The heat source heat pump system for large temperature difference and long distance heating according to claim 1, characterized in that: The expander (101) has a built-in double cylinder, which is composed of a first expander (101-1) with a larger cylinder volume and a second expander (101-2) with a smaller cylinder volume. The condensing heat exchanger (102) is composed of a first condensing heat exchanger (102-1) and a second condensing heat exchanger (102-2). The water from the primary heat network passes through the first condensing heat exchanger (102-1) and the second condensing heat exchanger (102-2) in sequence. The ORC working fluid in the first condensing heat exchanger (102-1) and the second condensing heat exchanger (102-2) comes from the first expander (101-1) and the second expander (101-2) respectively, and is pumped by a first working fluid pump (103-1) and a second working fluid pump (103-2) respectively. The average temperature and pressure of the ORC working fluid in the first condensing heat exchanger (102-1) are lower than those in the second condensing heat exchanger (102-2).

7. The heat source heat pump system for large temperature difference and long distance heating according to claim 1, characterized in that: The compressor (201) has two built-in cylinders, and is composed of a first compressor (201-1) with a lower exhaust pressure and a second compressor (201-2) with a higher exhaust pressure. The condenser (202) is composed of a first condenser (202-1) and a second condenser (202-2). The water from the primary heat network passes through the first condenser (202-1) and the second condenser (202-2) in sequence. The heat pump working fluid in the first condenser (202-1) and the second condenser (202-2) comes from the first compressor (201-1) and the second compressor (201-2) respectively. The average temperature and pressure of the heat pump working fluid in the first condenser (202-1) are lower than those in the second condenser (202-2).

8. The heat source heat pump system for large temperature difference and long distance heating according to claim 1, characterized in that: The primary heating network water outlet is provided with an auxiliary heating device (700). When the organic Rankine cycle device and the vapor compression heat pump are insufficient to heat the primary heating network water to a specified temperature, the auxiliary heating device (700) uses high-grade heat for supplementary heating.

Images