A high-temperature heat pump system with a preheater and a cascade evaporator gradient heat extraction mode

Abstract

This invention discloses a high-temperature heat pump system with a series evaporator and a cascaded heat extraction mode, belonging to the technical field of compression heat pumps. It includes a condenser and a first preheater, as well as a jet evaporation module and a compression buffer module. To address the problems of poor heat exchange on the condenser side and low ejector entrainment efficiency, and to achieve interstage liquid spray cooling, this invention uses a series evaporator mode on the evaporator side, enabling cascaded utilization of evaporation temperature. A preheater is installed at the condenser outlet, forming a staged heating structure optimization, which is beneficial to improving the system's heat exchange efficiency and thermodynamic matching. Simultaneously, the mainstream refrigerant entering the ejector is cooled, further enhancing the ejector's entrainment capability and achieving a good intermediate cooling effect; or, by further adding a preheater, the heating temperature range can be expanded, improving system performance.

Description

Technical Field

[0001] This invention relates to the technical field of compression heat pumps, and more particularly to a high-temperature heat pump system with a series evaporator cascade heat extraction mode and a preheater. Background Technology

[0002] Currently, compression heat pump systems are widely used in building heating, industrial waste heat recovery, and other fields. The core heat exchange process involves releasing heat from the high-pressure refrigerant to the water side via a condenser to produce hot water. To improve system efficiency and hot water output quality, some heat pump systems incorporate a dual-evaporator structure. By operating two evaporators in series with an intermediate liquid injection cooling device, the discharge temperature in the middle section of the compressor is effectively reduced, improving system operational stability.

[0003] Regarding the aforementioned technologies, it has been found that in existing "dual evaporator series + ejector intermediate liquid spray cooling" systems, the high-pressure liquid refrigerant at the condenser outlet is usually not further heat-treated, resulting in incomplete condensation heat recovery and limited potential for improving system energy efficiency. On the other hand, as a key component of intermediate liquid spray cooling, if the subcooling of the mainstream high-pressure liquid refrigerant in the ejector is insufficient, it will be difficult to obtain a sufficient expansion enthalpy difference within the nozzle, leading to reduced driving capability, poor ejection effect, and further impacting mixing efficiency and intermediate cooling capacity.

[0004] In summary, to achieve the cascade utilization of condensation heat, improve refrigerant subcooling, enhance ejector performance, and optimize hot water heating curves, it is urgent to propose a heat pump system solution with a reasonable structure, optimized heat exchange path, and higher energy efficiency, so as to further break through the thermal limitations of existing systems and improve overall performance. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing a high-temperature heat pump system with a series evaporator cascade heat extraction mode and a preheater. This system aims to solve the problems of poor heat exchange effect on the condenser side and low ejector induction efficiency, while simultaneously achieving interstage liquid spray cooling.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0007] A high-temperature heat pump system with a series evaporator cascade heat extraction mode and a preheater includes a condenser and a first preheater, and also includes a jet evaporation module and a compression buffer module;

[0008] The jet evaporation module includes at least one gas-liquid separation tank and at least two sets of jet evaporation units. Each jet evaporation unit includes an ejector and an evaporator. At least one set of jet evaporation units is connected in series with a gas-liquid separation tank. The gas-liquid separation tank is placed between the ejector and the evaporator. Both sides of the gas-liquid separation tank are connected to at least one evaporator. Adjacent sets of jet evaporation units are connected in parallel with each other, and the evaporators of adjacent sets of jet evaporation units are connected to each other.

[0009] The compression buffer module includes at least one set of compression buffer units. Each set of compression buffer units includes a compressor and an injection buffer tank. Adjacent sets of compression buffer units are connected in series with each other through a compressor and an injection buffer tank.

[0010] The condenser is connected to the first preheater, the first preheater is connected to the jet evaporation module, the jet evaporation module is connected to the compression buffer module, and the compression buffer module is connected to the condenser.

[0011] Furthermore, the jet evaporation module includes a first evaporator, a second evaporator, a first ejector, a second ejector, and a gas-liquid separator;

[0012] The compression buffer module includes a first compressor, a first injection buffer tank, a second compressor, and a second injection buffer tank;

[0013] The hot water outlet of the condenser is connected to a third condensing-side hot water pipe, the hot water inlet of the condenser is connected to a second condensing-side hot water pipe, the hot water outlet of the first preheater is connected to the second condensing-side hot water pipe, and the hot water inlet of the first preheater is connected to the first condensing-side hot water pipe.

[0014] The refrigerant outlet of the condenser is connected to a refrigerant condensing pipe. The inlet of the first preheater is connected to the refrigerant condensing pipe. The outlet of the first preheater is connected to a second mainstream pipe. The second mainstream pipe is connected to the mainstream inlet of the second ejector. The mixing outlet of the second ejector is connected to a second mixing pipe. The second mixing pipe is connected to the inlet of the second ejector buffer tank. The outlet of the second ejector buffer tank is connected to a third refrigerant gaseous pipe. The third refrigerant gaseous pipe is connected to the inlet of the second compressor. The outlet of the second compressor is connected to a fourth refrigerant gaseous pipe. The fourth refrigerant gaseous pipe is connected to the refrigerant inlet of the condenser.

[0015] The outlet end of the second injection buffer tank is connected to the first mainstream pipeline, which is connected to the mainstream inlet end of the first injector. The mixing outlet end of the first injector is connected to the first mixing pipeline, which is connected to the inlet end of the first injection buffer tank. The outlet end of the first injection buffer tank is connected to the first refrigerant gas pipeline, which is connected to the inlet end of the first compressor. The outlet end of the first compressor is connected to the second refrigerant gas pipeline, which is connected to the inlet end of the second injection buffer tank.

[0016] The heat source water inlet of the first evaporator is connected to the first evaporation side hot water pipe, the heat source water outlet of the first evaporator is connected to the second evaporation side hot water pipe, the second evaporation side hot water pipe is connected to the heat source water inlet of the second evaporator, and the heat source water outlet of the second evaporator is connected to the third evaporation side hot water pipe.

[0017] The refrigerant outlet of the first evaporator is connected to a second jet pipe, which is connected to the jet inlet of the second ejector. The outlet of the gas-liquid separator is connected to a first jet pipe, which is connected to the jet inlet of the first ejector. The inlet of the gas-liquid separator is connected to a second refrigerant gas-liquid two-phase pipe, which is connected to the refrigerant outlet of the second evaporator.

[0018] The outlet of the gas-liquid separator is connected to the refrigerant inlet of the first evaporator, and the outlet of the first injection buffer tank is connected to the refrigerant inlet of the second evaporator.

[0019] Furthermore, the first spray buffer tank is provided with a first baffle, which is positioned above the inlet of the first mixing pipeline, and the second spray buffer tank is provided with a second baffle, which is positioned above the inlet of the second mixing pipeline.

[0020] Furthermore, a first expansion valve is provided between the outlet end of the first injection buffer tank and the refrigerant inlet end of the second evaporator. The inlet end of the first expansion valve is connected to a first refrigerant liquid pipeline, which is connected to the outlet end of the first injection buffer tank. The outlet end of the first expansion valve is connected to a first refrigerant gas-liquid two-phase pipeline, which is connected to the refrigerant inlet end of the second evaporator.

[0021] Furthermore, a second expansion valve is provided between the outlet end of the gas-liquid separator and the refrigerant inlet end of the first evaporator. The inlet end of the second expansion valve is connected to a second refrigerant liquid pipeline, which is connected to the outlet end of the gas-liquid separator. The outlet end of the second expansion valve is connected to a third refrigerant gas-liquid two-phase pipeline, which is connected to the refrigerant inlet end of the first evaporator.

[0022] Furthermore, including a second preheater, the jet evaporation module includes a first evaporator, a second evaporator, a first ejector, a second ejector, and a gas-liquid separator;

[0023] The compression buffer module includes a first compressor, a second compressor, a first injection buffer tank, and a second injection buffer tank;

[0024] The hot water inlet of the second preheater is connected to the fourth condenser-side hot water pipe, the hot water outlet of the second preheater is connected to the fifth condenser-side hot water pipe, the fifth condenser-side hot water pipe is connected to the hot water inlet of the first preheater, the hot water outlet of the first preheater is connected to the second condenser-side hot water pipe, the second condenser-side hot water pipe is connected to the hot water inlet of the condenser, and the hot water outlet of the condenser is connected to the second condenser-side hot water pipe.

[0025] The refrigerant outlet of the condenser is connected to a refrigerant condensing pipe, which is connected to the inlet of the first preheater. The outlet of the first preheater is connected to a second main flow pipe, which is connected to the main flow inlet of the second ejector. The mixing outlet of the second ejector is connected to a second mixing pipe, which is connected to the inlet of the second ejector buffer tank. The outlet of the second ejector buffer tank is connected to a third refrigerant gaseous pipe, which is connected to the inlet of the second compressor. The outlet of the second compressor is connected to a fourth refrigerant gaseous pipe, which is connected to the refrigerant inlet of the condenser.

[0026] The outlet of the second preheater is connected to a fourth mainstream pipeline, which is connected to the mainstream inlet of the first ejector. The mixing outlet of the first ejector is connected to a first mixing pipeline, which is connected to the inlet of the first injection buffer tank. The outlet of the first injection buffer tank is connected to a first refrigerant gaseous pipeline, which is connected to the inlet of the first compressor. The outlet of the first compressor is connected to a second refrigerant gaseous pipeline, which is connected to the inlet of the second injection buffer tank. The outlet of the second injection buffer tank is connected to a third mainstream pipeline, which is connected to the inlet of the second preheater.

[0027] The heat source water inlet of the first evaporator is connected to the first evaporation side hot water pipe, the heat source water outlet of the first evaporator is connected to the second evaporation side hot water pipe, the second evaporation side hot water pipe is connected to the heat source water inlet of the second evaporator, and the heat source water outlet of the second evaporator is connected to the third evaporation side hot water pipe.

[0028] The refrigerant outlet of the first evaporator is connected to a second jet pipe, which is connected to the jet inlet of the second ejector. The outlet of the gas-liquid separator is connected to a first jet pipe, which is connected to the jet inlet of the first ejector. The inlet of the gas-liquid separator is connected to a second refrigerant gas-liquid two-phase pipe, which is connected to the refrigerant outlet of the second evaporator.

[0029] The outlet of the gas-liquid separator is connected to the refrigerant inlet of the first evaporator, and the outlet of the first injection buffer tank is connected to the refrigerant inlet of the second evaporator.

[0030] Furthermore, the first spray buffer tank is provided with a first baffle, which is positioned above the inlet of the first mixing pipeline.

[0031] Furthermore, the second spray buffer tank is provided with a second baffle, which is positioned above the inlet of the second mixing pipeline.

[0032] Furthermore, a first expansion valve is provided between the outlet end of the first injection buffer tank and the refrigerant inlet end of the second evaporator. The inlet end of the first expansion valve is connected to a first refrigerant liquid pipeline, which is connected to the outlet end of the first injection buffer tank. The outlet end of the first expansion valve is connected to a first refrigerant gas-liquid two-phase pipeline, which is connected to the refrigerant inlet end of the second evaporator.

[0033] Furthermore, a second expansion valve is provided between the outlet end of the gas-liquid separator and the refrigerant inlet end of the first evaporator. The inlet end of the second expansion valve is connected to a second refrigerant liquid pipeline, which is connected to the outlet end of the gas-liquid separator. The outlet end of the second expansion valve is connected to a third refrigerant gas-liquid two-phase pipeline, which is connected to the refrigerant inlet end of the first evaporator.

[0034] In summary, compared with the prior art, the beneficial effects of the above technical solution are:

[0035] 1. By adding a preheater, this application reduces the initial enthalpy of the mainstream refrigerant entering the ejector, converting more enthalpy difference into kinetic energy, increasing the injection speed, enhancing the ejection capability, and promoting momentum exchange between the mainstream and the ejector flow, thereby improving the overall efficiency of the ejector.

[0036] 2. When the ejector of this application is used for intermediate liquid injection cooling, its inlet stream is gaseous refrigerant from the evaporator outlet, while the main stream is liquid refrigerant. The subcooled main stream is injected more thoroughly, absorbing more heat from the superheated steam, thereby enhancing the intermediate cooling effect, reducing the intermediate section and exhaust temperature of the compressor, alleviating the compressor's thermal load, and extending the equipment's lifespan.

[0037] 3. This application introduces the hot water medium on the condenser side sequentially into the subcooler and condenser, forming a flow structure of inlet water → preheating → main heating. This allows the heat in the high-temperature section to be mainly released by the condenser, while the heat in the low-temperature section is recovered through the preheater. This thermodynamic matching method can significantly improve the heat transfer driving force, reduce the end temperature difference, improve the overall heat exchange efficiency on the condenser side, maximize the recovery of residual sensible heat at the condenser outlet, and avoid energy waste.

[0038] 4. This application further expands the range of hot water uplift on the condenser side by setting up a two-stage preheater, optimizes the system structure, and improves heat exchange performance. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of a first embodiment of a high-temperature heat pump system with a series evaporator and a cascade heat extraction mode with a preheater according to the present invention.

[0040] Figure 2 This is a schematic diagram of a second embodiment of a high-temperature heat pump system with a series evaporator and a preheater for cascade heat extraction according to the present invention.

[0041] Explanation of reference numerals in the attached figures:

[0042] 1. Condenser; 2. First preheater; 3. Second evaporator; 4. First evaporator; 5. Second preheater; 6. First compressor; 7. Second compressor; 8. First injection buffer tank; 9. Second injection buffer tank; 10. Gas-liquid separator; 11. First expansion valve; 12. Second expansion valve; 13. First ejector; 14. Second ejector; 15. First baffle; 16. Second baffle;

[0043] 31. First condenser-side hot water pipe; 32. Second condenser-side hot water pipe; 33. Third condenser-side hot water pipe; 34. Fourth condenser-side hot water pipe; 35. Fifth condenser-side hot water pipe; 41. First evaporator-side hot water pipe; 42. Second evaporator-side hot water pipe; 43. Third evaporator-side hot water pipe; 51. First refrigerant gaseous pipe; 52. Second refrigerant gaseous pipe; 53. Third refrigerant gaseous pipe; 54. Fourth refrigerant gaseous pipe; 55. ... 61. Refrigerant condensation line; 62. First refrigerant liquid line; 63. First refrigerant gas-liquid two-phase line; 64. Second refrigerant liquid line; 65. Third refrigerant gas-liquid two-phase line; 71. First mainstream line; 72. Second mainstream line; 73. Third mainstream line; 74. Fourth mainstream line; 75. First ejector line; 76. Second ejector line; 81. First mixing line; 82. Second mixing line. Detailed Implementation

[0044] The principles and features of the present invention are described below with reference to all the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0045] This invention discloses a high-temperature heat pump system with a series evaporator cascade heat extraction mode and a preheater.

[0046] Example 1

[0047] Reference Figure 1As shown, a high-temperature heat pump system with a series evaporator cascade heat extraction mode and a preheater includes a condenser 1, a first preheater 2, a first evaporator 4, a second evaporator 3, a first compressor 6, a second compressor 7, a first injection buffer tank 8, a second injection buffer tank 9, a gas-liquid separator 10, a first ejector 13, and a second ejector 14.

[0048] The hot water outlet of condenser 1 is connected to a third condensing side hot water pipe 33, the hot water inlet of condenser 1 is connected to a second condensing side hot water pipe 32, the hot water outlet of the first preheater 2 is connected to the second condensing side hot water pipe 32, and the hot water inlet of the first preheater 2 is connected to a first condensing side hot water pipe 31.

[0049] The refrigerant outlet of condenser 1 is connected to a refrigerant condensing pipe 55. The inlet of the first preheater 2 is connected to the refrigerant condensing pipe 55. The outlet of the first preheater 2 is connected to a second mainstream pipe 72. The second mainstream pipe 72 is connected to the mainstream inlet of the second ejector 14. The mixing outlet of the second ejector 14 is connected to a second mixing pipe 82. The second mixing pipe 82 is connected to the inlet of the second injection buffer tank 9. The outlet of the second injection buffer tank 9 is connected to a third refrigerant gaseous pipe 53. The third refrigerant gaseous pipe 53 is connected to the inlet of the second compressor 7. The outlet of the second compressor 7 is connected to a fourth refrigerant gaseous pipe 54. The fourth refrigerant gaseous pipe 54 is connected to the refrigerant inlet of condenser 1.

[0050] The second injection buffer tank 9 is equipped with a second baffle 16, which is positioned above the inlet of the second mixing pipeline 82.

[0051] The outlet end of the second injection buffer tank 9 is connected to the first mainstream pipeline 71, which is connected to the mainstream inlet end of the first injector 13. The mixing outlet end of the first injector 13 is connected to the first mixing pipeline 81, which is connected to the inlet end of the first injection buffer tank 8. The outlet end of the first injection buffer tank 8 is connected to the first refrigerant gas pipeline 51, which is connected to the inlet end of the first compressor 6. The outlet end of the first compressor 6 is connected to the second refrigerant gas pipeline 52, which is connected to the inlet end of the second injection buffer tank 9.

[0052] The first spray buffer tank 8 is provided with a first baffle 15, which is positioned above the inlet of the first mixing pipeline 81.

[0053] The first evaporator 4 is connected to the first evaporation side hot water pipe 41 at the heat source water inlet end, and to the second evaporation side hot water pipe 42 at the heat source water outlet end. The second evaporation side hot water pipe 42 is connected to the heat source water inlet end of the second evaporator 3, and to the third evaporation side hot water pipe 43 at the heat source water outlet end of the second evaporator 3.

[0054] The refrigerant outlet of the first evaporator 4 is connected to a second jet pipe 76, which is connected to the jet inlet of the second ejector 14. The outlet of the gas-liquid separator 10 is connected to a first jet pipe 75, which is connected to the jet inlet of the first ejector 13. The inlet of the gas-liquid separator 10 is connected to a second refrigerant gas-liquid two-phase pipe 63, which is connected to the refrigerant outlet of the second evaporator 3.

[0055] The outlet end of the gas-liquid separator 10 is connected to the refrigerant inlet end of the first evaporator 4, and the outlet end of the first injection buffer tank 8 is connected to the refrigerant inlet end of the second evaporator 3.

[0056] A first expansion valve 11 is provided between the outlet end of the first injection buffer tank 8 and the refrigerant inlet end of the second evaporator 3. The inlet end of the first expansion valve 11 is connected to a first refrigerant liquid pipeline 61, which is connected to the outlet end of the first injection buffer tank 8. The outlet end of the first expansion valve 11 is connected to a first refrigerant gas-liquid two-phase pipeline 62, which is connected to the refrigerant inlet end of the second evaporator 3.

[0057] A second expansion valve 12 is provided between the outlet end of the gas-liquid separator 10 and the refrigerant inlet end of the first evaporator 4. The inlet end of the second expansion valve 12 is connected to a second refrigerant liquid pipeline 64, which is connected to the outlet end of the gas-liquid separator 10. The outlet end of the second expansion valve 12 is connected to a third refrigerant gas-liquid two-phase pipeline 65, which is connected to the refrigerant inlet end of the first evaporator 4.

[0058] The specific plan is as follows:

[0059] This invention provides a high-temperature heat pump system with a series evaporator cascade heat extraction mode and a preheater, including a condenser 1, a first preheater 2, a first evaporator 4, a second evaporator 3, a first compressor 6, a second compressor 7, a first injection buffer tank 8, a second injection buffer tank 9, a gas-liquid separator 10, a first expansion valve 11, a second expansion valve 12, a first ejector 13, a second ejector 14, a first baffle 15, a second baffle 16, a first condensing-side hot water pipe 31, a second condensing-side hot water pipe 32, a third condensing-side hot water pipe 33, a first evaporating-side hot water pipe 41, and a second evaporating-side hot water pipe 42. Water pipe 42, third evaporator side hot water pipe 43, first refrigerant gaseous pipe 51, second refrigerant gaseous pipe 52, third refrigerant gaseous pipe 53, fourth refrigerant gaseous pipe 54, refrigerant condenser pipe 55, first refrigerant liquid pipe 61, first refrigerant gas-liquid two-phase pipe 62, second refrigerant gas-liquid two-phase pipe 63, second refrigerant liquid pipe 64, third refrigerant gas-liquid two-phase pipe 65, first main flow pipe 71, second main flow pipe 72, first ejector flow pipe 75, second ejector flow pipe 76, first mixing pipe 81, second mixing pipe 82.

[0060] The outlet end of the first condensing side hot water pipe 31 is connected to the hot water inlet end of the first preheater 2, the hot water outlet end of the first preheater 2 is connected to the inlet end of the second condensing side hot water pipe 32, the outlet end of the second condensing side hot water pipe 32 is connected to the hot water inlet end of the condenser 1, and the hot water outlet end of the condenser 1 is connected to the inlet end of the third condensing side hot water pipe 33.

[0061] The outlet end of the first evaporation side hot water pipe 41 is connected to the heat source water inlet end of the first evaporator 4, the heat source water outlet end of the first evaporator 4 is connected to the inlet end of the second evaporation side hot water pipe 42, the outlet end of the second evaporation side hot water pipe 42 is connected to the heat source water inlet end of the second evaporator 3, and the heat source water outlet end of the second evaporator 3 is connected to the inlet end of the third evaporation side hot water pipe 43.

[0062] The refrigerant outlet of condenser 1 is connected to the inlet of refrigerant condensing pipe 55. The outlet of refrigerant condensing pipe 55 is connected to the inlet of first preheater 2. The outlet of first preheater 2 is connected to the inlet of second main pipe 72. The outlet of second main pipe 72 is connected to the main inlet of second ejector 14. The refrigerant outlet of first evaporator 4 is connected to the inlet of second ejector pipe 76. The mixing outlet of second ejector 14 is connected to the inlet of second mixing pipe 82. The outlet of second mixing pipe 82 is connected to the upper left inlet of second injection buffer tank 9. Second baffle 16 is installed on the upper side of the outlet of second mixing pipe 82 in second injection buffer tank 9.

[0063] The lower left outlet of the second injection buffer tank 9 is connected to the inlet of the first mainstream pipeline 71. The outlet of the first mainstream pipeline 71 is connected to the mainstream inlet of the first injector 13. The top outlet of the gas-liquid separator 10 is connected to the inlet of the first jet pipeline 75. The outlet of the first jet pipeline 75 is connected to the jet inlet of the first injector 13. The mixed flow outlet of the first injector 13 is connected to the inlet of the first mixed pipeline 81. The outlet of the first mixed pipeline 81 is connected to the left inlet of the first injection buffer tank 8. The first baffle 15 is installed on the upper side of the outlet of the first mixed pipeline 81 in the first injection buffer tank 8.

[0064] The right-side outlet of the first injection buffer tank 8 is connected to the inlet of the first refrigerant liquid pipeline 61. The outlet of the first refrigerant liquid pipeline 61 is connected to the inlet of the first expansion valve 11. The outlet of the first expansion valve 11 is connected to the inlet of the first refrigerant gas-liquid two-phase pipeline 62. The outlet of the first refrigerant gas-liquid two-phase pipeline 62 is connected to the refrigerant inlet of the second evaporator 3. The refrigerant outlet of the second evaporator 3 is connected to the inlet of the second refrigerant gas-liquid two-phase pipeline 63. The outlet end of the second refrigerant gas-liquid two-phase pipeline 63 is connected to the right inlet end of the gas-liquid separator 10, the left outlet end of the gas-liquid separator 10 is connected to the inlet end of the second refrigerant liquid pipeline 64, the outlet end of the second refrigerant liquid pipeline 64 is connected to the inlet end of the second expansion valve 12, the outlet end of the second expansion valve 12 is connected to the inlet end of the third refrigerant gas-liquid two-phase pipeline 65, and the outlet end of the third refrigerant gas-liquid two-phase pipeline 65 is connected to the refrigerant inlet end of the first evaporator 4.

[0065] The top outlet of the first injection buffer tank 8 is connected to the inlet of the first refrigerant gaseous pipeline 51. The outlet of the first refrigerant gaseous pipeline 51 is connected to the inlet of the first compressor 6. The outlet of the first compressor 6 is connected to the inlet of the second refrigerant gaseous pipeline 52. The outlet of the second refrigerant gaseous pipeline 52 is connected to the right inlet of the second injection buffer tank 9. The top outlet of the second injection buffer tank 9 is connected to the inlet of the third refrigerant gaseous pipeline 53. The outlet of the third refrigerant gaseous pipeline 53 is connected to the inlet of the second compressor 7. The outlet of the second compressor 7 is connected to the inlet of the fourth refrigerant gaseous pipeline 54. The outlet of the fourth refrigerant gaseous pipeline 54 is connected to the refrigerant inlet of the condenser 1.

[0066] Compared with existing technologies, the beneficial effects of the above technical solution are:

[0067] This application reduces the initial enthalpy of the mainstream refrigerant entering the ejector by adding a preheater, allowing more enthalpy difference to be converted into kinetic energy, increasing the injection speed, enhancing the ejection capability, and promoting momentum exchange between the mainstream and the ejector flow, thereby improving the overall efficiency of the ejector.

[0068] When the ejector of this application is used for intermediate liquid injection cooling, its inlet stream is gaseous refrigerant from the evaporator outlet, while the main stream is liquid refrigerant. The subcooled main stream is injected more thoroughly, absorbing more heat from the superheated vapor, thereby enhancing the intermediate cooling effect, reducing the intermediate section and exhaust temperature of the compressor, alleviating the compressor's thermal load, and extending the equipment's lifespan.

[0069] This application introduces the hot water medium on the condensing side sequentially into the subcooler and condenser 1, forming a flow structure of inlet water → preheating → main heating. This allows the heat in the high-temperature section to be mainly released by condenser 1, while the heat in the low-temperature section is recovered through the preheater. This thermodynamic matching method can significantly improve the heat transfer driving force, reduce the end temperature difference, improve the overall heat exchange efficiency on the condensing side, maximize the recovery of residual sensible heat at the outlet of condenser 1, and avoid energy waste.

[0070] This application further expands the range of hot water uplift on the condenser side by setting up a two-stage preheater, optimizes the system structure, and improves heat exchange performance.

[0071] The implementation principle of Example 1 is as follows:

[0072] After the refrigerant releases heat in the condenser 1 and its temperature decreases, it continues to enter the first preheater 2 for subcooling. Then, it becomes a high-speed, low-pressure fluid through the main nozzle of the second ejector 14, drawing out the gaseous refrigerant from the outlet of the first evaporator 4. The two are mixed in the second ejector 14 and then diffused before being injected into the second injection buffer tank 9, further reducing the temperature of the refrigerant from the first compressor 6. The condensed liquid refrigerant serves as the main working fluid in the first ejector 13, drawing out the gaseous refrigerant separated from the gas-liquid separator 10. The two fluids are mixed in the first ejector 13 and then diffused before being injected into the first injection buffer tank 8. The liquid refrigerant enters the second evaporator 3 after being throttled and depressurized by the first expansion valve 11. After absorbing heat, it enters the gas-liquid separator 10. A portion of the gaseous refrigerant is drawn into the mixing chamber by the first ejector 13 to complete the cycle, while the other portion continues to enter the second expansion valve 12 for secondary throttling and depressurization, and then enters the first evaporator 4, serving as the ejector fluid to enter the second ejector 14 to complete the cycle.

[0073] The gaseous refrigerant from the first ejector 13 enters the first compressor 6 for primary compression. The compressed gaseous refrigerant then enters the second ejector buffer tank 9, where it undergoes heat exchange with the two-phase mixed refrigerant and its temperature decreases. It then enters the second compressor 7 for secondary compression. The compressed gaseous water enters the condenser 1 to release latent heat, thereby heating the condenser pipes.

[0074] Overall, this design achieves two effects: First, by adding a preheater, the initial enthalpy of the mainstream refrigerant entering the ejector is reduced, increasing the injection velocity and enhancing the ejection capability. The subcooled mainstream refrigerant is injected more thoroughly, absorbing more heat from the superheated vapor, thus strengthening the intercooling effect, reducing the temperature of the compressor's intermediate section and exhaust, alleviating the compressor's thermal load, and extending equipment life. Second, this thermodynamic matching method significantly improves the heat transfer driving force, reduces the end temperature difference, and increases the overall heat exchange efficiency on the condenser side.

[0075] This invention promotes momentum exchange between the main stream and the ejector stream, improving the overall efficiency of the ejector. Simultaneously, it maximizes the recovery of residual sensible heat at the condenser 1 outlet, avoiding energy waste. The overall system performance coefficient is significantly superior to traditional single-ejector utilization technologies.

[0076] Example 2

[0077] Reference Figure 2 As shown, the difference between this embodiment and Embodiment 1 is that it has two preheaters.

[0078] A high-temperature heat pump system with a series evaporator cascade heat extraction mode and a preheater includes a condenser 1, a first preheater 2, a second preheater 5, a first evaporator 4, a second evaporator 3, a first compressor 6, a second compressor 7, a first injection buffer tank 8, a second injection buffer tank 9, a gas-liquid separator 10, a first ejector 13, and a second ejector 14.

[0079] The hot water inlet of the second preheater 5 is connected to the fourth condenser-side hot water pipe 34, and the hot water outlet of the second preheater 5 is connected to the fifth condenser-side hot water pipe 35. The fifth condenser-side hot water pipe 35 is connected to the hot water inlet of the first preheater 2. The hot water outlet of the first preheater 2 is connected to the second condenser-side hot water pipe 32. The second condenser-side hot water pipe 32 is connected to the hot water inlet of the condenser 1, and the hot water outlet of the condenser 1 is connected to the second condenser-side hot water pipe 32.

[0080] The refrigerant outlet of condenser 1 is connected to a refrigerant condensing pipe 55, which is connected to the inlet of the first preheater 2. The outlet of the first preheater 2 is connected to a second mainstream pipe 72, which is connected to the mainstream inlet of the second ejector 14. The mixing outlet of the second ejector 14 is connected to a second mixing pipe 82, which is connected to the inlet of the second injection buffer tank 9. The outlet of the second injection buffer tank 9 is connected to a third refrigerant gaseous pipe 53, which is connected to the inlet of the second compressor 7. The outlet of the second compressor 7 is connected to a fourth refrigerant gaseous pipe 54, which is connected to the refrigerant inlet of condenser 1.

[0081] The second injection buffer tank 9 is equipped with a second baffle 16, which is positioned above the inlet of the second mixing pipeline 82.

[0082] The outlet end of the second preheater 5 is connected to the fourth mainstream pipeline 74, which is connected to the mainstream inlet end of the first ejector 13. The mixing flow outlet end of the first ejector 13 is connected to the first mixing pipeline 81, which is connected to the inlet end of the first injection buffer tank 8. The outlet end of the first injection buffer tank 8 is connected to the first refrigerant gaseous pipeline 51, which is connected to the inlet end of the first compressor 6. The outlet end of the first compressor 6 is connected to the second refrigerant gaseous pipeline 52, which is connected to the inlet end of the second injection buffer tank 9. The outlet end of the second injection buffer tank 9 is connected to the third mainstream pipeline 73, which is connected to the inlet end of the second preheater 5.

[0083] The first spray buffer tank 8 is provided with a first baffle 15, which is positioned above the inlet of the first mixing pipeline 81.

[0084] The first evaporator 4 is connected to the first evaporation side hot water pipe 41 at the heat source water inlet end, and to the second evaporation side hot water pipe 42 at the heat source water outlet end. The second evaporation side hot water pipe 42 is connected to the heat source water inlet end of the second evaporator 3, and to the third evaporation side hot water pipe 43 at the heat source water outlet end of the second evaporator 3.

[0085] The refrigerant outlet of the first evaporator 4 is connected to a second jet pipe 76, which is connected to the jet inlet of the second ejector 14. The outlet of the gas-liquid separator 10 is connected to a first jet pipe 75, which is connected to the jet inlet of the first ejector 13. The inlet of the gas-liquid separator 10 is connected to a second refrigerant gas-liquid two-phase pipe 63, which is connected to the refrigerant outlet of the second evaporator 3.

[0086] The outlet end of the gas-liquid separator 10 is connected to the refrigerant inlet end of the first evaporator 4, and the outlet end of the first injection buffer tank 8 is connected to the refrigerant inlet end of the second evaporator 3.

[0087] A first expansion valve 11 is provided between the outlet end of the first injection buffer tank 8 and the refrigerant inlet end of the second evaporator 3. The inlet end of the first expansion valve 11 is connected to a first refrigerant liquid pipeline 61, which is connected to the outlet end of the first injection buffer tank 8. The outlet end of the first expansion valve 11 is connected to a first refrigerant gas-liquid two-phase pipeline 62, which is connected to the refrigerant inlet end of the second evaporator 3.

[0088] A second expansion valve 12 is provided between the outlet end of the gas-liquid separator 10 and the refrigerant inlet end of the first evaporator 4. The inlet end of the second expansion valve 12 is connected to a second refrigerant liquid pipeline 64, which is connected to the outlet end of the gas-liquid separator 10. The outlet end of the second expansion valve 12 is connected to a third refrigerant gas-liquid two-phase pipeline 65, which is connected to the refrigerant inlet end of the first evaporator 4.

[0089] The specific plan is as follows:

[0090] This invention provides a high-temperature heat pump system with a series evaporator cascade heat extraction mode and preheaters, including a condenser 1, a first preheater 2, a second preheater 5, a first evaporator 4, a second evaporator 3, a first compressor 6, a second compressor 7, a first injection buffer tank 8, a second injection buffer tank 9, a gas-liquid separator 10, a first expansion valve 11, a second expansion valve 12, a first ejector 13, a second ejector 14, a first baffle 15, a second baffle 16, a second condensing-side hot water pipe 32, a third condensing-side hot water pipe 33, a fourth condensing-side hot water pipe 34, a fifth condensing-side hot water pipe 35, a first evaporating-side hot water pipe 41, and a second evaporating-side hot water pipe 42. Second evaporator side hot water pipe 42, third evaporator side hot water pipe 43, first refrigerant gaseous pipe 51, second refrigerant gaseous pipe 52, third refrigerant gaseous pipe 53, fourth refrigerant gaseous pipe 54, refrigerant condenser pipe 55, first refrigerant liquid pipe 61, first refrigerant gas-liquid two-phase pipe 62, second refrigerant gas-liquid two-phase pipe 63, second refrigerant liquid pipe 64, third refrigerant gas-liquid two-phase pipe 65, second main flow pipe 72, third main flow pipe 73, fourth main flow pipe 74, first ejector pipe 75, second ejector pipe 76, first mixing pipe 81, second mixing pipe 82.

[0091] The outlet end of the fourth condensing side hot water pipe 34 is connected to the hot water inlet end of the second preheater 5. The hot water outlet end of the second preheater 5 is connected to the inlet end of the fifth condensing side hot water pipe 35. The outlet end of the fifth condensing side hot water pipe 35 is connected to the hot water inlet end of the first preheater 2. The hot water outlet end of the first preheater 2 is connected to the inlet end of the second condensing side hot water pipe 32. The outlet end of the second condensing side hot water pipe 32 is connected to the hot water inlet end of the condenser 1. The hot water outlet end of the condenser 1 is connected to the inlet end of the third condensing side hot water pipe 33.

[0092] The outlet end of the first evaporation side hot water pipe 41 is connected to the heat source water inlet end of the first evaporator 4, the heat source water outlet end of the first evaporator 4 is connected to the inlet end of the second evaporation side hot water pipe 42, the outlet end of the second evaporation side hot water pipe 42 is connected to the heat source water inlet end of the second evaporator 3, and the heat source water outlet end of the second evaporator 3 is connected to the inlet end of the third evaporation side hot water pipe 43.

[0093] The refrigerant outlet of condenser 1 is connected to the inlet of refrigerant condensing pipe 55. The outlet of refrigerant condensing pipe 55 is connected to the inlet of first preheater 2. The outlet of first preheater 2 is connected to the inlet of second main pipe 72. The outlet of second main pipe 72 is connected to the main inlet of second ejector 14. The refrigerant outlet of first evaporator 4 is connected to the inlet of second ejector pipe 76. The mixing outlet of second ejector 14 is connected to the inlet of second mixing pipe 82. The outlet of second mixing pipe 82 is connected to the upper left inlet of second injection buffer tank 9. Second baffle 16 is installed on the upper side of the outlet of second mixing pipe 82 in second injection buffer tank 9.

[0094] The lower left outlet of the second injection buffer tank 9 is connected to the inlet of the third main flow pipeline 73. The outlet of the third main flow pipeline 73 is connected to the refrigerant inlet of the second preheater 5. The refrigerant outlet of the second preheater 5 is connected to the inlet of the fourth main flow pipeline 74. The outlet of the fourth main flow pipeline 74 is connected to the jet inlet of the first injector 13. The mixing outlet of the first injector 13 is connected to the inlet of the first mixing pipeline 81. The outlet of the first mixing pipeline 81 is connected to the left inlet of the first injection buffer tank 8. The first baffle 15 is installed on the upper side of the outlet of the first mixing pipeline 81 in the first injection buffer tank 8.

[0095] The right-side outlet of the first injection buffer tank 8 is connected to the inlet of the first refrigerant liquid pipeline 61. The outlet of the first refrigerant liquid pipeline 61 is connected to the inlet of the first expansion valve 11. The outlet of the first expansion valve 11 is connected to the inlet of the first refrigerant gas-liquid two-phase pipeline 62. The outlet of the first refrigerant gas-liquid two-phase pipeline 62 is connected to the refrigerant inlet of the second evaporator 3. The refrigerant outlet of the second evaporator 3 is connected to the inlet of the second refrigerant gas-liquid two-phase pipeline 63. The outlet end of the second refrigerant gas-liquid two-phase pipeline 63 is connected to the right inlet end of the gas-liquid separator 10, the left outlet end of the gas-liquid separator 10 is connected to the inlet end of the second refrigerant liquid pipeline 64, the outlet end of the second refrigerant liquid pipeline 64 is connected to the inlet end of the second expansion valve 12, the outlet end of the second expansion valve 12 is connected to the inlet end of the third refrigerant gas-liquid two-phase pipeline 65, and the outlet end of the third refrigerant gas-liquid two-phase pipeline 65 is connected to the refrigerant inlet end of the first evaporator 4.

[0096] The top outlet of the first injection buffer tank 8 is connected to the inlet of the first refrigerant gaseous pipeline 51. The outlet of the first refrigerant gaseous pipeline 51 is connected to the inlet of the first compressor 6. The outlet of the first compressor 6 is connected to the inlet of the second refrigerant gaseous pipeline 52. The outlet of the second refrigerant gaseous pipeline 52 is connected to the right inlet of the second injection buffer tank 9. The top outlet of the second injection buffer tank 9 is connected to the inlet of the third refrigerant gaseous pipeline 53. The outlet of the third refrigerant gaseous pipeline 53 is connected to the inlet of the second compressor 7. The outlet of the second compressor 7 is connected to the inlet of the fourth refrigerant gaseous pipeline 54. The outlet of the fourth refrigerant gaseous pipeline 54 is connected to the refrigerant inlet of the condenser 1.

[0097] Compared with existing technologies, the beneficial effects of the above technical solution are:

[0098] This application reduces the initial enthalpy of the mainstream refrigerant entering the ejector by adding a preheater, allowing more enthalpy difference to be converted into kinetic energy, increasing the injection speed, enhancing the ejection capability, and promoting momentum exchange between the mainstream and the ejector flow, thereby improving the overall efficiency of the ejector.

[0099] When the ejector of this application is used for intermediate liquid injection cooling, its inlet stream is gaseous refrigerant from the evaporator outlet, while the main stream is liquid refrigerant. The subcooled main stream is injected more thoroughly, absorbing more heat from the superheated vapor, thereby enhancing the intermediate cooling effect, reducing the intermediate section and exhaust temperature of the compressor, alleviating the compressor's thermal load, and extending the equipment's lifespan.

[0100] This application introduces the hot water medium on the condensing side sequentially into the subcooler and condenser 1, forming a flow structure of inlet water → preheating → main heating. This allows the heat in the high-temperature section to be mainly released by condenser 1, while the heat in the low-temperature section is recovered through the preheater. This thermodynamic matching method can significantly improve the heat transfer driving force, reduce the end temperature difference, improve the overall heat exchange efficiency on the condensing side, maximize the recovery of residual sensible heat at the outlet of condenser 1, and avoid energy waste.

[0101] This application further expands the range of hot water uplift on the condenser side by setting up a two-stage preheater, optimizes the system structure, and improves heat exchange performance.

[0102] The implementation principle of Example 2 is as follows:

[0103] After the refrigerant releases heat in the condenser 1 and its temperature decreases, it continues to enter the first preheater 2 for subcooling. Then, it passes through the main nozzle of the second ejector 14 and becomes a high-speed, low-pressure fluid, which entrains the gaseous refrigerant at the outlet of the first evaporator 4. The two are mixed in the second ejector 14 and then diffused before being injected into the second injection buffer tank 9, further reducing the temperature of the refrigerant from the first compressor 6. The condensed liquid refrigerant enters the second preheater 5 for further subcooling, and then becomes the mainstream working fluid in the first ejector 13, entraining the gaseous refrigerant separated from the gas-liquid separator 10. The two fluids are mixed in the first ejector 13 and then diffused before being injected into the first injection buffer tank 8. The liquid refrigerant enters the second evaporator 3 after being throttled and depressurized by the first expansion valve 11. After absorbing heat, it enters the gas-liquid separator 10. Part of the gaseous refrigerant is entrained by the first ejector 13 into the mixing chamber to complete the cycle, while the other part continues to enter the second expansion valve 12 for secondary throttling and depressurization, and then enters the first evaporator 4, where it becomes the entrained fluid and enters the second ejector 14 to complete the cycle.

[0104] The gaseous refrigerant from the first ejector 13 enters the first compressor 6 for primary compression. The compressed gaseous refrigerant then enters the second ejector buffer tank 9, where it undergoes heat exchange with the two-phase mixed refrigerant and its temperature decreases. It then enters the second compressor 7 for secondary compression. The compressed gaseous water enters the condenser 1 to release latent heat, thereby heating the condenser pipes.

[0105] Overall, this system achieves two effects: First, it sequentially introduces the hot water medium on the condenser side into the subcooler and condenser 1, forming a flow structure of inlet water → preheating → main heating. This ensures that heat in the high-temperature section is primarily released by condenser 1, while heat in the low-temperature section is recovered through the preheater. Second, by increasing the number of preheaters, the temperature range of the hot water on the condenser side is further expanded from the original 60℃~100℃ to 40℃~100℃, optimizing the system structure and improving heat exchange performance. Third, replacing the expansion valve with an ejector reduces the refrigerant temperature and pressure at the condenser outlet, minimizing usable energy loss, increasing the compressor inlet pressure, and enhancing system energy efficiency.

[0106] Overall, moderate subcooling of liquid refrigerant not only helps to enhance heating potential but also improves ejector ignition conditions, further enhancing system stability and heat exchange efficiency.

[0107] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-temperature heat pump system with a series evaporator cascade heat extraction mode and a preheater, comprising a condenser (1) and a first preheater (2), characterized in that: It also includes a jet evaporation module and a compression buffer module; The jet evaporation module includes a gas-liquid separator (10) and at least two sets of jet evaporation units. Each jet evaporation unit includes an ejector and an evaporator. At least one set of jet evaporation units is connected in series with the gas-liquid separator (10). The gas-liquid separator (10) is placed between the ejector and the evaporator. Adjacent sets of jet evaporation units are connected in parallel with each other, and the evaporators of adjacent sets of jet evaporation units are connected to each other. The compression buffer module includes at least one set of compression buffer units. Each set of compression buffer units includes a compressor and an injection buffer tank. Adjacent sets of compression buffer units are connected in series with each other through a compressor and an injection buffer tank. The condenser (1) is connected to the first preheater (2), the first preheater (2) is connected to the jet evaporation module, the jet evaporation module is connected to the compression buffer module, and the compression buffer module is connected to the condenser (1). The jet evaporation module includes a first evaporator (4), a second evaporator (3), a first ejector (13), a second ejector (14), and a gas-liquid separator (10); The compression buffer module includes a first compressor (6), a first injection buffer tank (8), a second compressor (7), and a second injection buffer tank (9); The hot water outlet of the condenser (1) is connected to the third condensing side hot water pipe (33), the hot water inlet of the condenser (1) is connected to the second condensing side hot water pipe (32), the hot water outlet of the first preheater (2) is connected to the second condensing side hot water pipe (32), and the hot water inlet of the first preheater (2) is connected to the first condensing side hot water pipe (31). The refrigerant outlet of the condenser (1) is connected to a refrigerant condensing pipe (55), the inlet of the first preheater (2) is connected to the refrigerant condensing pipe (55), the outlet of the first preheater (2) is connected to a second mainstream pipe (72), the second mainstream pipe (72) is connected to the mainstream inlet of the second ejector (14), the mixing outlet of the second ejector (14) is connected to a second mixing pipe (82), the second mixing pipe (82) is connected to the inlet of the second injection buffer tank (9), the outlet of the second injection buffer tank (9) is connected to a third refrigerant gaseous pipe (53), the third refrigerant gaseous pipe (53) is connected to the inlet of the second compressor (7), the outlet of the second compressor (7) is connected to a fourth refrigerant gaseous pipe (54), and the fourth refrigerant gaseous pipe (54) is connected to the refrigerant inlet of the condenser (1). The outlet end of the second injection buffer tank (9) is connected to the first mainstream pipeline (71), the first mainstream pipeline (71) is connected to the mainstream inlet end of the first injector (13), the mixing flow outlet end of the first injector (13) is connected to the first mixing pipeline (81), the first mixing pipeline (81) is connected to the inlet end of the first injection buffer tank (8), the gas outlet end of the first injection buffer tank (8) is connected to the first refrigerant gas pipeline (51), the first refrigerant gas pipeline (51) is connected to the inlet end of the first compressor (6), the outlet end of the first compressor (6) is connected to the second refrigerant gas pipeline (52), the second refrigerant gas pipeline (52) is connected to the inlet end of the second injection buffer tank (9); The first evaporator (4) is connected to the first evaporation side hot water pipe (41) at the heat source water inlet end, and the first evaporator (4) is connected to the second evaporation side hot water pipe (42) at the heat source water outlet end. The second evaporation side hot water pipe (42) is connected to the heat source water inlet end of the second evaporator (3), and the second evaporator (3) is connected to the third evaporation side hot water pipe (43) at the heat source water outlet end. The refrigerant outlet of the first evaporator (4) is connected to a second jet pipe (76), which is connected to the jet inlet of the second ejector (14). The outlet of the gas-liquid separator (10) is connected to a first jet pipe (75), which is connected to the jet inlet of the first ejector (13). The inlet of the gas-liquid separator (10) is connected to a second refrigerant gas-liquid two-phase pipe (63), which is connected to the refrigerant outlet of the second evaporator (3). The outlet end of the gas-liquid separator (10) is connected to the refrigerant inlet end of the first evaporator (4), and the outlet end of the first injection buffer tank (8) is connected to the refrigerant inlet end of the second evaporator (3).

2. A high-temperature heat pump system with a preheater and a series evaporator cascade heat extraction mode according to claim 1, characterized in that: The first spray buffer tank (8) is provided with a first baffle (15), which is positioned above the inlet of the first mixing pipeline (81). The second spray buffer tank (9) is provided with a second baffle (16), which is positioned above the inlet of the second mixing pipeline (82).

3. A high-temperature heat pump system with a preheater and a series evaporator cascade heat extraction mode according to claim 1, characterized in that: A first expansion valve (11) is provided between the outlet end of the first injection buffer tank (8) and the refrigerant inlet end of the second evaporator (3). The inlet end of the first expansion valve (11) is connected to a first refrigerant liquid pipeline (61). The first refrigerant liquid pipeline (61) is connected to the outlet end of the first injection buffer tank (8). The outlet end of the first expansion valve (11) is connected to a first refrigerant gas-liquid two-phase pipeline (62). The first refrigerant gas-liquid two-phase pipeline (62) is connected to the refrigerant inlet end of the second evaporator (3).

4. A high-temperature heat pump system with a preheater and a series evaporator cascade heat extraction mode according to claim 1, characterized in that: A second expansion valve (12) is provided between the outlet end of the gas-liquid separator (10) and the refrigerant inlet end of the first evaporator (4). The inlet end of the second expansion valve (12) is connected to a second refrigerant liquid pipeline (64). The second refrigerant liquid pipeline (64) is connected to the outlet end of the gas-liquid separator (10). The outlet end of the second expansion valve (12) is connected to a third refrigerant gas-liquid two-phase pipeline (65). The third refrigerant gas-liquid two-phase pipeline (65) is connected to the refrigerant inlet end of the first evaporator (4).

5. A high-temperature heat pump system with a series evaporator cascade heat extraction mode and a preheater, comprising a condenser (1) and a first preheater (2), characterized in that: It also includes a jet evaporation module and a compression buffer module; The jet evaporation module includes a gas-liquid separator (10) and at least two sets of jet evaporation units. Each jet evaporation unit includes an ejector and an evaporator. At least one set of jet evaporation units is connected in series with the gas-liquid separator (10). The gas-liquid separator (10) is placed between the ejector and the evaporator. Adjacent sets of jet evaporation units are connected in parallel with each other, and the evaporators of adjacent sets of jet evaporation units are connected to each other. The compression buffer module includes at least one set of compression buffer units. Each set of compression buffer units includes a compressor and an injection buffer tank. Adjacent sets of compression buffer units are connected in series with each other through a compressor and an injection buffer tank. The condenser (1) is connected to the first preheater (2), the first preheater (2) is connected to the jet evaporation module, the jet evaporation module is connected to the compression buffer module, and the compression buffer module is connected to the condenser (1). The jet evaporation module includes a second preheater (5), a first evaporator (4), a second evaporator (3), a first jet (13), a second jet (14), and a gas-liquid separator (10). The compression buffer module includes a first compressor (6), a second compressor (7), a first injection buffer tank (8), and a second injection buffer tank (9); The hot water inlet of the second preheater (5) is connected to the fourth condensing side hot water pipe (34), the hot water outlet of the second preheater (5) is connected to the fifth condensing side hot water pipe (35), the fifth condensing side hot water pipe (35) is connected to the hot water inlet of the first preheater (2), the hot water outlet of the first preheater (2) is connected to the second condensing side hot water pipe (32), the second condensing side hot water pipe (32) is connected to the hot water inlet of the condenser (1), and the hot water outlet of the condenser (1) is connected to the second condensing side hot water pipe (32). The refrigerant outlet of the condenser (1) is connected to a refrigerant condensing pipe (55), which is connected to the inlet of the first preheater (2). The outlet of the first preheater (2) is connected to a second main pipe (72), which is connected to the main inlet of the second ejector (14). The mixing outlet of the second ejector (14) is connected to a second mixing pipe (82), which is connected to the inlet of the second injection buffer tank (9). The outlet of the second injection buffer tank (9) is connected to a third refrigerant gaseous pipe (53), which is connected to the inlet of the second compressor (7). The outlet of the second compressor (7) is connected to a fourth refrigerant gaseous pipe (54), which is connected to the refrigerant inlet of the condenser (1). The outlet end of the second preheater (5) is connected to the fourth mainstream pipeline (74), the fourth mainstream pipeline (74) is connected to the mainstream inlet end of the first injector (13), the mixing flow outlet end of the first injector (13) is connected to the first mixing pipeline (81), the first mixing pipeline (81) is connected to the inlet end of the first injection buffer tank (8), the outlet end of the first injection buffer tank (8) is connected to the first refrigerant gas pipeline (51), the first refrigerant gas pipeline (51) is connected to the inlet end of the first compressor (6), the outlet end of the first compressor (6) is connected to the second refrigerant gas pipeline (52), the second refrigerant gas pipeline (52) is connected to the inlet end of the second injection buffer tank (9), the outlet end of the second injection buffer tank (9) is connected to the third mainstream pipeline (73), the third mainstream pipeline (73) is connected to the inlet end of the second preheater (5); The first evaporator (4) is connected to the first evaporation side hot water pipe (41) at the heat source water inlet end, and the first evaporator (4) is connected to the second evaporation side hot water pipe (42) at the heat source water outlet end. The second evaporation side hot water pipe (42) is connected to the heat source water inlet end of the second evaporator (3), and the second evaporator (3) is connected to the third evaporation side hot water pipe (43) at the heat source water outlet end. The refrigerant outlet of the first evaporator (4) is connected to a second jet pipe (76), which is connected to the jet inlet of the second ejector (14). The outlet of the gas-liquid separator (10) is connected to a first jet pipe (75), which is connected to the jet inlet of the first ejector (13). The inlet of the gas-liquid separator (10) is connected to a second refrigerant gas-liquid two-phase pipe (63), which is connected to the refrigerant outlet of the second evaporator (3). The outlet end of the gas-liquid separator (10) is connected to the refrigerant inlet end of the first evaporator (4), and the outlet end of the first injection buffer tank (8) is connected to the refrigerant inlet end of the second evaporator (3).

6. A high-temperature heat pump system with a preheater and a series evaporator cascade heat extraction mode according to claim 5, characterized in that: The first spray buffer tank (8) is provided with a first baffle (15), which is positioned above the inlet of the first mixing pipeline (81).

7. A high-temperature heat pump system with a preheater and a series evaporator cascade heat extraction mode according to claim 5, characterized in that: The second spray buffer tank (9) is provided with a second baffle (16), which is positioned above the inlet of the second mixing pipeline (82).

8. A high-temperature heat pump system with a preheater and a series evaporator cascade heat extraction mode according to claim 5, characterized in that: A first expansion valve (11) is provided between the outlet end of the first injection buffer tank (8) and the refrigerant inlet end of the second evaporator (3). The inlet end of the first expansion valve (11) is connected to a first refrigerant liquid pipeline (61). The first refrigerant liquid pipeline (61) is connected to the outlet end of the first injection buffer tank (8). The outlet end of the first expansion valve (11) is connected to a first refrigerant gas-liquid two-phase pipeline (62). The first refrigerant gas-liquid two-phase pipeline (62) is connected to the refrigerant inlet end of the second evaporator (3).

9. A high-temperature heat pump system with a preheater and a series evaporator cascade heat extraction mode according to claim 5, characterized in that: A second expansion valve (12) is provided between the outlet end of the gas-liquid separator (10) and the refrigerant inlet end of the first evaporator (4). The inlet end of the second expansion valve (12) is connected to a second refrigerant liquid pipeline (64). The second refrigerant liquid pipeline (64) is connected to the outlet end of the gas-liquid separator (10). The outlet end of the second expansion valve (12) is connected to a third refrigerant gas-liquid two-phase pipeline (65). The third refrigerant gas-liquid two-phase pipeline (65) is connected to the refrigerant inlet end of the first evaporator (4).

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