A dual-source dual-flash mixed working fluid compression high-temperature heat pump system

Abstract

The present invention discloses a dual-source dual-flash mixed working fluid compression high-temperature heat pump system, which belongs to the technical field of high-temperature heat pump systems. The present invention realizes the recovery of dual-source heat energy by using dual-source mixed working fluids and dual-temperature evaporators in the system, utilizes dual compressors for multi-stage compression, and arranges dual flash evaporators and evaporative condensers to perform diversion expansion flash evaporation and heat recovery on the mixed working fluids, thereby realizing the separation of high-boiling point working fluids and low-boiling point working fluids and the air replenishment and enthalpy increase process of the compressor, reducing the energy loss in the compression and expansion processes, adopting a preheater and a first condenser in the heat production circuit, realizing two-stage heat exchange for heat production, reducing the heat loss of large temperature difference heat exchange, and finally effectively realizing the dual-source heat energy recovery and improving the heating energy efficiency of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature heat pump systems, and in particular to a dual-source dual-flash mixed working fluid compression high-temperature heat pump system. Background Art

[0002] As a green and sustainable energy technology, high temperature heat pump can realize the recycling and reuse of heat energy and has been widely recognized. In terms of heat energy utilization, high temperature heat pump system can recycle a large amount of waste heat energy generated in the marine industry and improve the quality of heat energy to make it into high temperature heat energy required for production, thereby improving the energy utilization efficiency of marine industrial production.

[0003] However, the traditional single-source high-temperature heat pump system can only recycle heat energy within a small temperature range, resulting in a limited amount of heat energy to be recycled. In the process of producing high-temperature heat, the high-pressure ratio compression and expansion process of the traditional single-source single-stage compression high-temperature heat pump will result in a large energy loss.

[0004] Based on the above content, a dual-source dual-flash mixed working fluid compression high-temperature heat pump system is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a dual-source dual-flash mixed working fluid compression high-temperature heat pump system to solve the problems in the above-mentioned background technology.

[0006] To achieve the above-mentioned objectives, the present invention provides a dual-source dual-flash mixed working fluid compression high-temperature heat pump system, comprising a low-temperature evaporator, a high-temperature evaporator, a first condenser and a preheater, wherein the low-temperature evaporator and the high-temperature evaporator are both connected to the first condenser, the first condenser is respectively connected to the evaporative condenser and the primary expansion flash unit, the outlet end of the evaporative condenser is connected to the secondary expansion flash unit, the secondary expansion flash unit is respectively connected to the high-temperature evaporator and the preheater, and the preheater is connected to the low-temperature evaporator.

[0007] Preferably, the low-temperature evaporator comprises a hot-end tube side and a cold-end shell side, the hot-end tube side is provided with a hot-end inlet and a hot-end outlet, and the cold-end shell side is provided with a cold-end inlet and a cold-end outlet; the high-temperature evaporator, the first condenser, the evaporative condenser, and the preheater have the same structural arrangement as the low-temperature evaporator.

[0008] Preferably, the hot end inlet of the low-temperature evaporator is connected to the low-temperature heat source recovery end, and the hot end outlet of the low-temperature evaporator is connected to the low-temperature heat source discharge end; the low-temperature heat source recovery end, the cold end shell side of the low-temperature evaporator and the low-temperature heat source discharge end are connected in sequence to form a low-temperature heat source heat energy recovery loop;

[0009] The hot end inlet of the high-temperature evaporator is connected to the high-temperature heat source recovery end, the hot end outlet of the high-temperature evaporator is connected to the high-temperature heat source discharge end, the high-temperature heat source recovery end, the hot end pipe of the high-temperature evaporator and the high-temperature heat source discharge end are connected in sequence to form a high-temperature heat source heat energy recovery loop.

[0010] Preferably, a first compressor and a second compressor are also provided on the connection route between the low-temperature evaporator and the first condenser, the first compressor is provided with a compression inlet, a compression outlet and an air supply port, and the second compressor has the same structural setting as the first compressor.

[0011] Preferably, the cold end outlet of the low-temperature evaporator is connected to the compression inlet of the first compressor, the cold end outlet of the high-temperature evaporator is connected to the air supply port of the first compressor, the compression outlet of the first compressor is connected to the compression inlet of the second compressor, and the compression outlet of the second compressor is connected to the hot end inlet of the first condenser.

[0012] Preferably, the primary expansion flash unit includes a first expansion valve and a first flash evaporator, the secondary expansion flash unit includes a second expansion valve and a second flash evaporator, a flash inlet, an upper outlet and a lower outlet are respectively provided on the tank cavity of the first flash evaporator, and the second flash evaporator has the same structural setting as the first flash evaporator.

[0013] Preferably, the first condenser is connected to the hot end inlet of the evaporative condenser and the first expansion valve respectively through a three-way diverter valve, the first expansion valve is connected to the flash inlet of the first flash evaporator, the upper outlet of the first flash evaporator is connected to the hot end inlet of the evaporative condenser, the lower outlet of the first flash evaporator is connected to the cold end inlet of the evaporative condenser, the cold end outlet of the evaporative condenser is connected to the air supply port of the second compressor, and the hot end outlet of the evaporative condenser is connected to the second expansion valve.

[0014] Preferably, the second expansion valve is connected to the flash inlet of the second flash evaporator, and the lower outlet of the second flash evaporator is connected to the cold end inlet of the high-temperature evaporator through a fourth expansion valve; the upper outlet of the second flash evaporator is connected to the hot end inlet of the preheater, and the hot end outlet of the preheater is connected to the cold end inlet of the low-temperature evaporator through a third expansion valve.

[0015] Preferably, the cold end inlet of the preheater is connected to the heat production inlet, the cold end outlet of the preheater is connected to the cold end inlet of the first condenser, and the cold end outlet of the first condenser is connected to the heat production outlet;

[0016] The heat production inlet, the cold shell side of the preheater, the cold shell side of the first condenser and the heat production outlet are connected in sequence to form a heat production loop.

[0017] Therefore, the present invention discloses a dual-source dual-flash mixed working fluid compression high-temperature heat pump system, which realizes the recovery of dual heat source heat energy by using dual-source mixed working fluid and dual-temperature evaporator in the system, utilizes dual compressors for multi-stage compression, and sets dual flash evaporators and evaporative condensers to perform diversion expansion flash evaporation and heat recovery on the mixed working fluid, thereby realizing the separation of high-boiling point working fluid and low-boiling point working fluid and the air replenishment and enthalpy increase process of the compressor, reducing the energy loss in the compression and expansion process, adopting preheater and the first condenser in the heat production circuit, realizing two-stage heat exchange of heat production, reducing the heat loss of large temperature difference heat exchange, and finally effectively realizing dual-source heat energy recovery and improving the heating energy efficiency of the system.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of an overall circuit of an embodiment of the present invention;

[0020] Figure 2 It is a structural schematic diagram of a low-temperature evaporator according to an embodiment of the present invention;

[0021] Figure 3 is a structural schematic diagram of a first flash evaporator according to an embodiment of the present invention;

[0022] Figure 4 is a structural schematic diagram of a first compressor according to an embodiment of the present invention;

[0023] Figure 5 It is the state node of each stage in the system of the present invention;

[0024] Reference numerals:

[0025] 1. Low-temperature heat source recovery end; 2. Low-temperature heat source discharge end; 3. Low-temperature evaporator; 31. Hot end pipe side; 32. Hot end inlet; 33. Hot end outlet; 34. Cold end shell side; 35. Cold end inlet; 36. Cold end outlet; 4. High-temperature heat source recovery end; 5. High-temperature heat source discharge end; 6. High-temperature evaporator; 7. First compressor; 71. Compression inlet; 72. Compression outlet; 73. Air supply port; 8. Second compressor; 9. Heat production outlet; 10. First condenser; 11. Three-way diverter valve; 12. First expansion valve; 13. Evaporative condenser; 14. First flash evaporator; 1401. Flash inlet; 1402. Upper outlet; 1403. Lower outlet; 15. Second expansion valve; 16. Second flash evaporator; 17. Preheater; 18. Heat production inlet; 19. Third expansion valve; 20. Fourth expansion valve. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings 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.

[0028] Example

[0029] like Figure 1-Figure 4 As shown, the present invention provides a dual-source dual-flash mixed working medium compression high-temperature heat pump system, including a low-temperature evaporator 3, a high-temperature evaporator 6, a first condenser 10 and a preheater 17. The low-temperature evaporator 3 and the high-temperature evaporator 6 are connected to the first condenser 10. The first condenser 10 is respectively connected to the evaporative condenser 13 and the primary expansion flash unit. The outlet end of the evaporative condenser 13 is connected to the secondary expansion flash unit. The secondary expansion flash unit is respectively connected to the high-temperature evaporator 6 and the preheater 17. The preheater 17 is connected to the low-temperature evaporator. The primary expansion flash unit includes a first expansion valve 12 and a first flash evaporator 14. The secondary expansion flash unit includes a second expansion valve 15 and a second flash evaporator 16. The tank cavity of the first flash evaporator 14 is respectively provided with a flash inlet 1401, an upper outlet 1402 and a lower outlet 1403. The second flash evaporator 16 has the same structural arrangement as the first flash evaporator 14.

[0030] Among them, the low-temperature evaporator 3, the high-temperature evaporator 6, the first condenser 10, the evaporative condenser 13, and the preheater 17 have the same structural settings, all of which include a hot end tube side 31 and a cold end shell side 34. The hot end tube side 31 is provided with a hot end inlet 32 ​​and a hot end outlet 33, and the hot end tube side 31, the hot end inlet 32 ​​and the hot end outlet 33 constitute the hot end. The cold end shell side 34 is provided with a cold end inlet 35 and a cold end outlet 36, and the cold end shell side 34, the cold end inlet 35 and the cold end outlet 36 constitute the cold end.

[0031] The hot end inlet of the low-temperature evaporator 3 is connected to the low-temperature heat source recovery end 1, and the hot end outlet of the low-temperature evaporator 3 is connected to the low-temperature heat source discharge end 2. The low-boiling-point working fluid in the low-temperature evaporator 3 absorbs heat to realize the heat energy recovery of the low-temperature heat source; the low-temperature heat source recovery end 1, the cold end shell side of the low-temperature evaporator 3 and the low-temperature heat source discharge end 2 are connected in sequence to form a low-temperature heat source heat energy recovery loop; the low-temperature heat source releases heat to the low-boiling-point working fluid in the cold end shell side of the low-temperature evaporator 3 through the hot end tube side of the low-temperature evaporator 3. After the heat release is completed, the low-temperature heat source is discharged to the low-temperature heat source discharge end 2 through the cold end outlet of the low-temperature evaporator 3, completing the low-temperature heat source heat energy recovery loop.

[0032] The hot end inlet of the high temperature evaporator 6 is connected to the high temperature heat source recovery end 4, and the hot end outlet of the high temperature evaporator 6 is connected to the high temperature heat source discharge end 5. The high boiling point working fluid absorbs the heat energy of the high temperature heat source in the high temperature evaporator 6. The high temperature heat source recovery end 4, the hot end pipe side of the high temperature evaporator 6 and the high temperature heat source discharge end 5 are connected in sequence to form a high temperature heat source heat energy recovery loop. The high temperature heat source releases heat to the high boiling point working fluid in the cold end shell side of the high temperature evaporator 6 through the hot end pipe side of the high temperature evaporator 6. After the heat release is completed, the high temperature heat source is discharged to the high temperature heat source discharge end 5 through the cold end outlet of the high temperature evaporator 6, completing the high temperature heat source heat energy recovery loop, thereby forming a low temperature heat source heat energy recovery loop and a high temperature heat source heat energy recovery loop. L1 and L2 are used as state nodes of the low temperature heat source, and L3 and L4 are used as state nodes of the low temperature heat source. Figure 5 shown.

[0033] A first compressor 7 and a second compressor 8 are also provided on the connection route between the low-temperature evaporator 3 and the first condenser 10 . The first compressor 7 is provided with a compression inlet 71 , a compression outlet 72 and an air supply port 73 . The second compressor 8 has the same structural setting as the first compressor 7 .

[0034] The cold end outlet of the low temperature evaporator 3 is connected to the compression inlet of the first compressor 7, the cold end outlet of the high temperature evaporator 6 is connected to the air supply port of the first compressor 7, the high boiling point working fluid and the low boiling point working fluid are mixed in the first compressor 7 for the first stage compression, the compression outlet of the first compressor 7 is connected to the compression inlet of the second compressor 8, and the compression outlet of the second compressor 8 is connected to the hot end inlet of the first condenser 10 for the second stage heat exchange of heat production. The mixed working fluid after two-stage compression passes through the hot end tube side of the first condenser 10 to the heat production in the cold end shell side of the first condenser 10 for the second stage heat exchange.

[0035] The hot end outlet of the first condenser 10 is connected to the inlet of the three-way diverter valve 11, the second outlet of the three-way diverter valve 11 is connected to the first expansion valve 12, the first expansion valve 12 is connected to the flash inlet of the first flash evaporator 14, and the diversion expansion flash is completed. The upper outlet of the first flash evaporator 14 merges with the first outlet of the three-way diverter valve 11 and is connected to the hot end inlet of the evaporative condenser 13. The gaseous low-boiling-point working medium in the first flash evaporator 14 and the mixed working medium in the first outlet of the three-way diverter valve 11 are mixed and enter the evaporative condenser 13 to complete condensation and heat release. The lower outlet of the first flash evaporator 14 is connected to the cold end inlet of the evaporative condenser 13, and the cold end outlet of the evaporative condenser 13 is connected to the air supply port of the second compressor 8. The liquid high-boiling-point working medium in the first flash evaporator 14 flows into the evaporative condenser 13 to absorb heat and evaporate into the second compressor 8 to complete the second stage compression of air supply, and the hot end outlet of the evaporative condenser 13 is connected to the second expansion valve 15. The second expansion valve 15 is connected to the flash inlet of the second flash evaporator 16 to complete the second flash expansion; the lower outlet of the second flash evaporator 16 is connected to the cold end inlet of the high-temperature evaporator 6 through the fourth expansion valve 20 to complete the high-temperature heat energy recovery heating process; the upper outlet of the second flash evaporator 16 is connected to the hot end inlet of the preheater 17, and the gaseous low-boiling-point working fluid flows into the preheater 17 through the upper outlet of the second flash evaporator 16 to complete the first stage of heat exchange for heat production; the hot end outlet of the preheater 17 is connected to the cold end inlet of the low-temperature evaporator 3 through the third expansion valve 19 to complete the low-temperature heat energy recovery heating process.

[0036] The double flash heating compression circulation loop of the present invention has double flash evaporators, double compressors, evaporative condensers and preheaters. The low boiling point working fluid absorbs heat energy from the low temperature heat source in the low temperature evaporator and then enters the first compressor 7. The high boiling point working fluid absorbs heat energy from the high temperature heat source in the high temperature evaporator 6 and enters the second compressor 8 from the air supply port of the second compressor 8. The two working fluids are mixed in the first compressor 7 for the first stage compression. Due to the higher temperature and lower compression ratio of the high boiling point working fluid, the energy consumption and liquid hammer risk of the first compressor 7 are reduced. After the first stage of compression, the working medium enters the second compressor 8. The working medium discharged from the second compressor 8 releases heat in the first condenser 10 and is then diverted at the three-way diverter valve 11. A portion of the mixed working medium is expanded and flashed with the first flash evaporator 14 through the first expansion valve 12. The gaseous low-boiling-point working medium flows out from the upper outlet of the first flash evaporator 14 and mixes with another portion of the mixed working medium to enter the evaporative condenser 13. The liquid high-boiling-point working medium flows from the lower outlet of the first flash evaporator 14 into the evaporative condenser 13 to absorb heat and become gaseous and enter the second compressor 8, completing the air replenishment, thereby reducing the second compressor 8. Energy consumption and liquid hammer risk; the mixed working fluid at the hot end of the evaporator condenser 13 releases heat and enters the second flash evaporator 16 through the second expansion valve 15 for a second expansion flash evaporation, and the gaseous low-boiling-point working fluid flows out from the upper outlet and enters the preheater 17 for the first stage heat exchange of the heat product. After the heat exchange, it returns to the low-temperature evaporator 3 through the third expansion valve 19 to complete the heat energy recovery and heating of the low-temperature heat source. The liquid high-boiling-point working fluid flows out from the lower outlet of the second flash evaporator 16 and returns to the high-temperature evaporator 6 through the fourth expansion valve 20 to complete the heat energy recovery and heating of the high-temperature heat source, forming a double flash heating compression cycle.

[0037] like Figure 5 As shown, L1 and L2 are used as the state nodes of the waste heat source, and R1 to R16 are used as the state nodes of the heating medium in the high-temperature heat pump system. Compared with ordinary high-temperature heat pumps, the system uses dual-source mixed medium and dual-temperature evaporator to realize the recovery of dual-source heat energy, uses dual compressors for multi-stage compression, and sets dual flash evaporators and evaporative condensers 13 to perform diversion expansion flash evaporation and heat recovery on the mixed medium, realizing the separation of high-boiling point medium and low-boiling point medium and the air replenishment and enthalpy increase process of the compressor, reducing the energy loss in the compression and expansion process, and finally effectively realizing the dual-source heat recovery and improving the heating energy efficiency of the system.

[0038] The cold end inlet of the preheater 17 is connected to the heat production inlet 18, the cold end outlet of the preheater 17 is connected to the cold end inlet of the first condenser 10, and the cold end outlet of the first condenser 10 is connected to the heat production outlet 9; the heat production inlet 18, the cold shell side of the preheater 17, the cold shell side of the first condenser 10 and the heat production outlet 9 are connected in sequence to form a heat production circuit. The heat production inlet 18 is connected to the cold end shell side of the preheater 17 through the cold end inlet of the preheater 17, and is connected to the cold end inlet of the first condenser 10 through the cold end outlet of the preheater 17, completing the connection of the first stage of heat exchange. The cold end shell side of the first condenser 10 is connected to the heat production outlet 9 through the cold end outlet, completing the connection of the second stage of heat exchange, thereby forming a heat production circuit. Q1 to Q3 are used as the state nodes of water in the steam production circuit, such as Figure 5 Compared with ordinary high-temperature heat pump systems, the preheater and condenser are used in the heat production circuit to achieve two-stage heat exchange for heat production and reduce heat loss in large temperature difference heat exchange.

[0039] Therefore, the present invention discloses a dual-source dual-flash mixed working fluid compression high-temperature heat pump system, which realizes the recovery of dual heat source heat energy by using dual-source mixed working fluid and dual-temperature evaporator in the system, utilizes dual compressors for multi-stage compression, and sets dual flash evaporators and evaporative condensers to perform diversion expansion flash evaporation and heat recovery on the mixed working fluid, thereby realizing the separation of high-boiling point working fluid and low-boiling point working fluid and the air replenishment and enthalpy increase process of the compressor, reducing the energy loss in the compression and expansion process, adopting preheater and the first condenser in the heat production circuit, realizing two-stage heat exchange of heat production, reducing the heat loss of large temperature difference heat exchange, and finally effectively realizing dual-source heat energy recovery and improving the heating energy efficiency of the system.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A dual-source dual-flash mixed working fluid compression high-temperature heat pump system, characterized in that: It includes a low-temperature evaporator, a high-temperature evaporator, a first condenser and a preheater, the low-temperature evaporator and the high-temperature evaporator are both connected to the first condenser, the first condenser is respectively connected to the evaporative condenser and the primary expansion flash evaporation unit, the outlet end of the evaporative condenser is connected to the secondary expansion flash evaporation unit, the secondary expansion flash evaporation unit is respectively connected to the high-temperature evaporator and the preheater, and the preheater is connected to the low-temperature evaporator; the low-temperature evaporator includes a hot end tube side and a cold end shell side, the hot end tube side is provided with a hot end inlet and a hot end outlet, and the cold end shell side is provided with a cold end inlet and a cold end outlet; the high-temperature evaporator, the first condenser, the evaporative condenser, the preheater and the low-temperature evaporator have the same structural settings; the hot end inlet of the low-temperature evaporator is connected to the low-temperature heat source recovery end, and the hot end outlet of the low-temperature evaporator is connected to the low-temperature heat source discharge end; the low-temperature heat source recovery end, the cold end shell side of the low-temperature evaporator and the low-temperature heat source discharge end are sequentially connected to form a low-temperature heat source heat energy recovery loop; A first compressor and a second compressor are also provided on the connection route between the low-temperature evaporator and the first condenser; the first compressor is provided with a compression inlet, a compression outlet and an air supply port, and the second compressor has the same structural arrangement as the first compressor; The hot end inlet of the high temperature evaporator is connected to the high temperature heat source recovery end, the hot end outlet of the high temperature evaporator is connected to the high temperature heat source discharge end, the high temperature heat source recovery end, the hot end pipe of the high temperature evaporator and the high temperature heat source discharge end are connected in sequence to form a high temperature heat source heat energy recovery loop; The cold end outlet of the low temperature evaporator is connected to the compression inlet of the first compressor, the cold end outlet of the high temperature evaporator is connected to the air supply port of the first compressor, the compression outlet of the first compressor is connected to the compression inlet of the second compressor, and the compression outlet of the second compressor is connected to the hot end inlet of the first condenser; The primary expansion flash unit comprises a first expansion valve and a first flash evaporator, the secondary expansion flash unit comprises a second expansion valve and a second flash evaporator, a flash inlet, an upper outlet and a lower outlet are respectively arranged on the tank cavity of the first flash evaporator, and the second flash evaporator has the same structural arrangement as the first flash evaporator; The first condenser is connected to the hot end inlet of the evaporative condenser and the first expansion valve respectively through a three-way diverter valve, the first expansion valve is connected to the flash inlet of the first flash evaporator, the upper outlet of the first flash evaporator is connected to the hot end inlet of the evaporative condenser, the lower outlet of the first flash evaporator is connected to the cold end inlet of the evaporative condenser, the cold end outlet of the evaporative condenser is connected to the air supply port of the second compressor, and the hot end outlet of the evaporative condenser is connected to the second expansion valve; the second expansion valve is connected to the flash inlet of the second flash evaporator, and the lower outlet of the second flash evaporator is connected to the cold end inlet of the high-temperature evaporator through the fourth expansion valve; the upper outlet of the second flash evaporator is connected to the hot end inlet of the preheater, and the hot end outlet of the preheater is connected to the cold end inlet of the low-temperature evaporator through the third expansion valve.

2. A dual-source dual-flash mixed working fluid compression high-temperature heat pump system according to claim 1, characterized in that: The cold end inlet of the preheater is connected to the heat production inlet, the cold end outlet of the preheater is connected to the cold end inlet of the first condenser, and the cold end outlet of the first condenser is connected to the heat production outlet; The heat production inlet, the cold shell side of the preheater, the cold shell side of the first condenser and the heat production outlet are connected in sequence to form a heat production loop.

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