A two-stage flash evaporation multi-stage heat recovery compression high-temperature heat pump system

Abstract

The present invention discloses a two-stage flash multi-stage heat recovery compression high-temperature heat pump system, which belongs to the technical field of high-temperature heat pump systems. The present invention uses dual compressors to perform multi-stage compression in the system heating compression circulation loop, and uses dual flash heat regenerators to recover heat and replenish air for the dual compressors, thereby reducing the energy consumption and liquid hammer risk of the compressors. In the expansion process, split heat recovery and multiple heat exchangers are used to perform graded heat exchange expansion to reduce losses in the expansion process. Multiple heat exchangers are used in the heat production loop to achieve graded heat exchange of heat production and reduce heat exchange losses. The graded expansion and graded heat exchange methods enable the heat pump system to be regulated according to the amount of waste heat recovery and heat production demand, thereby effectively improving the system heating capacity and heating energy efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature heat pump systems, and in particular to a two-stage flash evaporation and multi-stage heat recovery compression high-temperature heat pump system. Background Art

[0002] As a green energy technology, heat pumps can improve the quality of thermal energy and are widely valued. In terms of marine energy reuse, high-temperature heat pump systems can recover a large amount of medium and low temperature waste heat generated in the marine industry, and combine the recovered medium and low temperature heat energy with electricity to produce the high temperature heat energy required by the marine industry, greatly improving the energy utilization rate of the marine industry and saving costs.

[0003] However, ordinary high-temperature heat pump systems cannot perform real-time regulation according to the actual waste heat recovery amount and heat production demand during waste heat recovery and reuse. The high-pressure ratio compression and expansion process will cause compressor liquid hammer and a large amount of energy loss. In addition, during the heat production process, the heat transfer process across large temperature conditions reduces the heat exchange efficiency of the condenser.

[0004] Based on this, a two-stage flash evaporation and multi-stage heat recovery compression high-temperature heat pump system is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a two-stage flash evaporation multi-stage heat recovery compression high-temperature heat pump system to solve the problems existing in the background technology.

[0006] To achieve the above-mentioned objectives, the present invention provides a two-stage flash multi-stage heat recovery compression high-temperature heat pump system, comprising an evaporator, a first heat recovery unit, a second heat recovery unit and a condenser, wherein the evaporator is connected to the first heat recovery unit, the first heat recovery unit and the second heat recovery unit are connected via a first compressor, the second heat recovery unit is connected to the condenser via a second compressor, and the condenser is connected to the first heat recovery unit via a first-stage flash heat recovery unit and a second-stage flash heat recovery unit in sequence.

[0007] Preferably, the primary flash heat recovery unit comprises a first flash heat recovery device and a first heat exchanger, the first flash heat recovery device comprises a flash shell side and a flash tube side, the flash shell side is provided with a shell side inlet and a shell side outlet, and the flash tube side is provided with a tube side inlet and a tube side outlet;

[0008] The secondary flash heat regeneration unit comprises a second flash heat regenerator and a second heat exchanger, and the second flash heat regenerator has the same structural configuration as the first flash heat regenerator.

[0009] Preferably, the evaporator is composed of a cold end shell side and a hot end tube side, the cold end shell side is provided with a cold end inlet and a cold end outlet, and the hot end tube side is provided with a hot end inlet and a hot end outlet; the first heat exchanger, the second heat exchanger, the condenser, the first regenerator, and the second regenerator have the same structural arrangement.

[0010] Preferably, the first compressor and the second compressor are both provided with an air inlet, an air outlet and an air supply outlet.

[0011] Preferably, the hot end inlet of the evaporator is connected to the waste heat recovery end, and the hot end outlet of the evaporator is connected to the waste heat discharge end.

[0012] Preferably, the cold end outlet of the evaporator is connected to the cold end inlet of the first heat regenerator, the cold end outlet of the first heat regenerator is connected to the air inlet of the first compressor, the air outlet of the first compressor is connected to the hot end inlet of the second heat regenerator, the hot end outlet of the second heat regenerator is connected to the air inlet of the second compressor, and the exhaust port of the second compressor is connected to the hot end inlet of the condenser.

[0013] Preferably, the hot end outlet of the condenser is connected to the first three-way diverter valve, one end of the first three-way diverter valve is connected to the tube side inlet of the first flash regenerator, the other end of the first three-way diverter valve is connected to the first expansion valve and the shell side inlet of the first flash regenerator in sequence, the shell side outlet of the first flash regenerator is connected to the air supply port of the second compressor, the tube side outlet of the first flash regenerator is connected to the hot end inlet of the second heat exchanger, and the hot end outlet of the second heat exchanger is connected to the second three-way diverter valve.

[0014] Preferably, one end of the second three-way diverter valve is connected to the cold end inlet of the second regenerator, the cold end outlet of the second regenerator is connected to the tube side inlet of the second flash regenerator, the tube side outlet of the second flash regenerator is connected to the hot end inlet of the second heat exchanger, and the hot end outlet of the second heat exchanger is connected to the hot end inlet of the first regenerator.

[0015] Preferably, one end of the second three-way diverter valve is connected to the shell side inlet of the second flash regenerator through the second expansion valve, and the shell side outlet of the second flash regenerator is connected to the air supply port of the first compressor; the tube side outlet of the second flash regenerator is connected to the hot end inlet of the second heat exchanger, the hot end outlet of the second heat exchanger is connected to the hot end inlet of the first regenerator, and the hot end outlet of the first regenerator is connected to the cold end inlet of the evaporator through the third expansion valve.

[0016] Preferably, the cold end inlet of the second heat exchanger is connected to the heat production inlet, the cold end outlet of the second heat exchanger is connected to the cold end inlet of the first heat exchanger, the cold end outlet of the first heat exchanger is connected to the cold end inlet of the condenser, and the cold end outlet of the condenser is connected to the heat production outlet.

[0017] Therefore, the present invention provides a two-stage flash multi-stage heat recovery compression high-temperature heat pump system. By using dual compressors for multi-stage compression in the system's heating compression circulation loop, a dual flash heat regenerator is used to recover heat and replenish air to the dual compressors, thereby reducing the energy consumption and liquid hammer risk of the compressors. During the expansion process, split heat recovery and multiple heat exchangers are used to perform graded heat exchange expansion, thereby reducing losses in the expansion process. Multiple heat exchangers are used in the heat production loop to achieve graded heat exchange of heat production, thereby reducing heat exchange losses. The graded expansion and graded heat exchange methods enable the heat pump system to be regulated according to the amount of waste heat recovered and the heat production demand, thereby effectively improving the system's heating capacity and heating energy efficiency.

[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 It is a schematic diagram of the overall system structure of an embodiment of the present invention;

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

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

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

[0023] Figure 5 A state node diagram of each stage of the system of an embodiment of the present invention;

[0024] Reference numerals:

[0025] 1. Waste heat recovery end; 2. Evaporator; 21. Cold end shell side; 22. Cold end inlet; 23. Cold end outlet; 24. Hot end pipe side; 25. Hot end inlet; 26. Hot end outlet; 3. First regenerator; 4. First compressor; 41. Air inlet; 42. Exhaust outlet; 43. Air supply outlet; 5. Second regenerator; 6. Second compressor; 7. Heat production outlet; 8. Condenser; 9. First three-way diverter valve; 10. First expansion Expansion valve; 11, first flash regenerator; 111, flash shell side; 112, shell side inlet; 113, shell side outlet; 114, flash tube side; 115, tube side inlet; 116, tube side outlet; 12, first heat exchanger; 13, second three-way diverter valve; 14, second expansion valve; 15, second flash regenerator; 16, second heat exchanger; 17, heat production inlet; 18, third expansion valve; 19, waste heat discharge end. 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 two-stage flash multi-stage heat recovery compression high-temperature heat pump system, including an evaporator 2, a first heat regenerator 3, a second heat regenerator 5 and a condenser 8, the evaporator 2 is connected to the first heat regenerator 3, the first heat regenerator 3 and the second heat regenerator 5 are connected through a first compressor 4, the second heat regenerator 5 is connected to the condenser 8 through a second compressor 6, and the condenser 8 is connected to the first heat regenerator 3 through a primary flash heat recovery unit and a secondary flash heat recovery unit in sequence. The first-stage flash heat recovery unit includes a first flash heat recovery device 11 and a first heat exchanger 12. The first flash heat recovery device 11 includes a flash shell side 111 and a flash tube side 114. The flash shell side 111 is provided with a shell side inlet 112 and a shell side outlet 113. The flash tube side 114 is provided with a tube side inlet 115 and a tube side outlet 116. The second-stage flash heat recovery unit includes a second flash heat recovery device 15 and a second heat exchanger 16. The second flash heat recovery device 15 has the same structural arrangement as the first flash heat recovery device 11.

[0030] The evaporator 2 is composed of a cold end shell side 21 and a hot end tube side 24. A cold end inlet 22 and a cold end outlet 23 are arranged on the cold end shell side 21, and a hot end inlet 25 and a hot end outlet 26 are arranged on the hot end tube side 24. The first heat exchanger 12, the second heat exchanger 16, the condenser 8, the first regenerator 3, and the second regenerator 5 have the same structural arrangement.

[0031] The first compressor 4 and the second compressor 6 are both provided with an air inlet 41 , an air outlet 42 and an air supply port 43 .

[0032] The hot end inlet of the evaporator 2 is connected to the waste heat recovery end 1, and the hot end outlet of the evaporator 2 is connected to the waste heat discharge end 19, forming a waste heat source recovery loop. The waste heat releases heat to the working fluid in the evaporator 2 to achieve waste heat energy recovery.

[0033] The cold end outlet of the evaporator 2 is connected to the cold end inlet of the first regenerator 3, and the cold end outlet of the first regenerator 3 is connected to the air inlet of the first compressor 4, so as to realize the first heat recovery and the first stage compression of the heating working medium in the heating compression cycle. The air outlet of the first compressor 4 is connected to the hot end inlet of the second regenerator 5, and the hot end outlet of the second regenerator 5 is connected to the air inlet of the second compressor 6, so as to realize the second heat recovery process and the second stage compression of the working medium, and the exhaust port of the second compressor 6 is connected to the hot end inlet of the condenser 8, so as to realize the final heat exchange of the heat product.

[0034] The hot end outlet of the condenser 8 is connected to the first three-way diverter valve 9, and the connection realizes the first diversion of the working medium. One end of the first three-way diverter valve 9 is connected to the tube side inlet of the first flash regenerator 11, and the unexpanded working medium enters the first flash regenerator 11; the other end of the first three-way diverter valve 9 is connected to the first expansion valve 10 and the shell side inlet of the first flash regenerator 11 in sequence, and the expanded working medium enters the first flash regenerator 11. The shell side outlet of the first flash regenerator 11 is connected to the air supply port of the second compressor 6, realizing the first diversion of the working medium, flash reheating and air supply. The unexpanded working medium enters the hot end inlet of the first flash regenerator 11 and releases heat to the working medium in the flash shell through the flash tube side, and is discharged from the tube side outlet after the heat release process is completed. After the working medium in the flash shell side absorbs heat, it is connected to the air supply port of the second compressor 6 through the tube side outlet to realize the compressor air supply process.

[0035] The tube outlet of the first flash regenerator 11 is connected to the hot end inlet of the second heat exchanger 16 to achieve the second stage of heat exchange for the heat product. The hot end outlet of the second heat exchanger 16 is connected to the second three-way diverter valve 13.

[0036] One end of the second three-way diverter valve 13 is connected to the cold end inlet of the second regenerator 5, and the cold end outlet of the second regenerator 5 is connected to the tube side inlet of the second flash regenerator 15 to perform a working medium heat recovery and heat absorption process; the tube side outlet of the second flash regenerator 15 is connected to the hot end inlet of the second heat exchanger 16 to achieve a first stage heat exchange for heat production; the hot end outlet of the second heat exchanger 16 is connected to the hot end inlet of the first regenerator 3 to perform a working medium heat release process.

[0037] One end of the second three-way diverter valve 13 is connected to the shell side inlet of the second flash regenerator 15 through the second expansion valve 14, so as to realize the second diversion flash regenerator gas replenishment of the working medium; the shell side outlet of the second flash regenerator 15 is connected to the gas replenishment port of the first compressor 4; the tube side outlet of the second flash regenerator 15 is connected to the hot end inlet of the second heat exchanger 16, the hot end outlet of the second heat exchanger 16 is connected to the hot end inlet of the first regenerator 3, and the hot end outlet of the first regenerator 3 is connected to the cold end inlet of the evaporator 2 through the third expansion valve 18, so as to carry out the final pressure reduction cycle of the working medium, thereby forming a heating compression circulation loop of a double flash multi-stage compression high temperature heat pump system.

[0038] The heating compression circulation loop has a double flash regenerator and a double compressor. The working fluid absorbs the medium and low temperature heat energy of the waste heat in the evaporator 2, and absorbs the excess heat of the circulating working fluid through the first regenerator 3 for heat recovery and flows to the first compressor 4. The working fluid is mixed with the working fluid of higher temperature and pressure provided by the second flash regenerator 15 in the first compressor 4 and then compressed in the first stage. After the working fluid releases part of the heat to the circulating working fluid through the second regenerator 5, it is mixed with the working fluid of higher temperature and pressure provided by the first flash regenerator 11 and then compressed in the second compressor 6 to further increase the temperature and pressure. After the high-temperature and high-pressure working fluid flows out of the second compressor 6, it exchanges heat with the heat product in the condenser 8. After releasing the heat, the working fluid flows through the first three-way diverter valve 9 for diversion. A part of the working fluid expands through the first expansion valve 10 to form a gas-liquid two-phase state and enters the cold end of the first flash regenerator 11, and the temperature and pressure are reduced. The other part of the working fluid directly enters the hot end of the first flash regenerator 11 to release heat to the cold end. The gaseous working medium that absorbs heat in the cold end of the first flash regenerator 11 is recompressed through the air supply port of the second compressor 6. Due to the higher temperature and pressure, the gaseous working medium is mixed with the inlet of the second compressor 6, which reduces the energy consumption and liquid hammer risk of the high pressure ratio compression of the second compressor 6. The working medium at the hot end of the first flash regenerator 11 flows through the first heat exchanger 12 to the heat product for the second stage of heat exchange, and then is diverted for the second time through the second three-way diverter valve 13. A part of the working medium flows into the hot end of the second flash regenerator 15 after absorbing heat through the second regenerator 5. The other part of the working medium expands through the second expansion valve 14 and then flows into the cold end of the second flash regenerator 15 after the temperature and pressure are reduced. The gaseous working medium that absorbs heat in the cold end of the second flash regenerator 15 replenishes the first compressor 4, reducing the compression energy consumption and liquid hammer risk of the first compressor 4. The working medium at the hot end of the second flash regenerator 15 flows out of the second flash regenerator 15 and performs the first stage of heat exchange with the heat product in the second heat exchanger 16. After further releasing heat in the first regenerator 3, the working fluid is cooled and depressurized by the third expansion valve 18 and enters the evaporator 2 to complete the heating compression cycle. L1 and L2 are used as the state nodes of the waste heat source, and R1 to R18 are used as the state nodes of the heating working fluid in the high-temperature heat pump system. Figure 5 As shown, compared with ordinary high-temperature heat pumps, this system uses dual compressors for multi-stage compression in the system's heating compression cycle loop, and uses double flash regenerators to recover heat and replenish air for the dual compressors, thereby reducing the energy consumption of the compressors and the risk of liquid hammer. During the expansion process, split heat recovery and multiple heat exchangers are used to perform staged heat exchange expansion, thereby reducing losses during the expansion process.

[0039] The cold end inlet of the second heat exchanger 16 is connected to the heat production inlet 17 for heat production supplementation, and the first heat absorption is completed in the first heat exchanger 12. The cold end outlet of the second heat exchanger 16 is connected to the cold end inlet of the first heat exchanger 12 to complete the connection of the first stage of heat exchange, and the second heat absorption is performed in the second heat exchanger 16; the cold end outlet of the first heat exchanger 12 is connected to the cold end inlet of the condenser 8 to complete the connection of the second stage of heat exchange, and the final heat exchange is completed in the condenser 8; the cold end outlet of the condenser 8 is connected to the heat production outlet to complete the connection of the third stage of heat exchange, and the heat production is discharged from the heat production outlet 7, thereby forming a heat production loop. Figure 5 As shown, Q1 to Q4 are used as the state nodes of water in the steam production circuit, and multiple heat exchangers are used in the heat production circuit to realize staged heat exchange of heat production, reduce heat exchange loss, and realize the ability of the heat pump system to be regulated according to the waste heat recovery amount and heat production demand in the form of staged expansion and staged heat exchange, ultimately effectively improving the system heating capacity and heating energy efficiency.

[0040] Therefore, the present invention provides a two-stage flash multi-stage heat recovery compression high-temperature heat pump system. By using dual compressors for multi-stage compression in the system's heating compression circulation loop, a dual flash heat regenerator is used to recover heat and replenish air to the dual compressors, thereby reducing the energy consumption and liquid hammer risk of the compressors. During the expansion process, split heat recovery and multiple heat exchangers are used to perform graded heat exchange expansion to reduce losses in the expansion process. Multiple heat exchangers are used in the heat production loop to achieve graded heat exchange of heat production and reduce heat exchange losses. The graded expansion and graded heat exchange methods enable the heat pump system to be regulated according to the amount of waste heat recovered and the heat production demand, thereby effectively improving the system's heating capacity and heating energy efficiency.

[0041] 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 two-stage flash evaporation multi-stage heat recovery compression high-temperature heat pump system, characterized in that: The invention comprises an evaporator, a first regenerator, a second regenerator and a condenser, wherein the evaporator is in communication with the first regenerator, the first regenerator and the second regenerator are connected via a first compressor, the second regenerator is connected to the condenser via a second compressor, and the condenser is connected to the first regenerator via a primary flash regenerator unit and a secondary flash regenerator unit in sequence; The primary flash regenerator unit comprises a first flash regenerator and a first heat exchanger, the first flash regenerator comprises a flash shell side and a flash tube side, the flash shell side is provided with a shell side inlet and a shell side outlet, the flash tube side is provided with a tube side inlet and a tube side outlet; The secondary flash heat recovery unit comprises a second flash heat regenerator and a second heat exchanger, and the second flash heat regenerator has the same structure as the first flash heat regenerator; The hot end outlet of the condenser is connected to the first three-way diverter valve, one end of the first three-way diverter valve is connected to the tube side inlet of the first flash regenerator, the other end of the first three-way diverter valve is connected to the first expansion valve and the shell side inlet of the first flash regenerator in sequence, the shell side outlet of the first flash regenerator is connected to the air supply port of the second compressor, the tube side outlet of the first flash regenerator is connected to the hot end inlet of the second heat exchanger, and the hot end outlet of the second heat exchanger is communicated with the second three-way diverter valve; one end of the second three-way diverter valve is connected to the cold end inlet of the second regenerator, the cold end outlet of the second regenerator is connected to the tube side inlet of the second flash regenerator, the tube side outlet of the second flash regenerator is connected to the hot end inlet of the second heat exchanger, and the hot end outlet of the second heat exchanger is connected to the hot end inlet of the first regenerator; One end of the second three-way diverter valve is connected to the shell side inlet of the second flash regenerator through the second expansion valve, and the shell side outlet of the second flash regenerator is connected to the air supply port of the first compressor; the tube side outlet of the second flash regenerator is connected to the hot end inlet of the second heat exchanger, the hot end outlet of the second heat exchanger is connected to the hot end inlet of the first regenerator, and the hot end outlet of the first regenerator is connected to the cold end inlet of the evaporator through the third expansion valve; The cold end inlet of the second heat exchanger is connected to the heat production inlet, the cold end outlet of the second heat exchanger is connected to the cold end inlet of the first heat exchanger, the cold end outlet of the first heat exchanger is connected to the cold end inlet of the condenser, and the cold end outlet of the condenser is connected to the heat production outlet.

2. A two-stage flash evaporation multi-stage heat recovery compression high-temperature heat pump system according to claim 1, characterized in that: The evaporator is composed of a cold end shell side and a hot end tube side. The cold end shell side is provided with a cold end inlet and a cold end outlet, and the hot end tube side is provided with a hot end inlet and a hot end outlet. The first heat exchanger, the second heat exchanger, the condenser, the first regenerator, and the second regenerator have the same structural arrangement.

3. A two-stage flash evaporation multi-stage heat recovery compression high-temperature heat pump system according to claim 2, characterized in that: The first compressor and the second compressor are both provided with an air inlet, an air outlet and an air supply outlet.

4. A two-stage flash evaporation multi-stage heat recovery compression high-temperature heat pump system according to claim 3, characterized in that: The hot end inlet of the evaporator is connected to the waste heat recovery end, and the hot end outlet of the evaporator is connected to the waste heat discharge end.

5. A two-stage flash evaporation multi-stage heat recovery compression high-temperature heat pump system according to claim 4, characterized in that: The cold end outlet of the evaporator is connected to the cold end inlet of the first reheater, the cold end outlet of the first reheater is connected to the air inlet of the first compressor, the air outlet of the first compressor is connected to the hot end inlet of the second reheater, the hot end outlet of the second reheater is connected to the air inlet of the second compressor, and the exhaust port of the second compressor is connected to the hot end inlet of the condenser.

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