An adjustable multi-stage heat exchange jet type mixed working fluid high-temperature heat pump system

Abstract

This invention relates to an adjustable multi-stage heat exchange jet-type mixed-works high-temperature heat pump system, belonging to the technical field of high-temperature heat pump systems. The mixed-works high-temperature heat pump system includes a mixed-works heat pump circulation loop and a gas-liquid jet-type water supply loop. The mixed-works heat pump circulation loop includes two compressors (low-pressure and high-pressure), a working fluid side for four condensers connected in series by two gas-liquid separators, a working fluid side for three evaporators, and two two-phase ejectors. The working fluid is a mixture of cis-1,3,3,3-tetrafluoropropylene and isopentane. The gas-liquid jet-type water supply loop includes gas-liquid ejectors, a water pump, and a water side for the three condensers. The mixed-works heat pump circulation loop and the gas-liquid jet-type water supply loop are coupled together. This invention utilizes two gas-liquid separators to form a four-stage condensation heat exchange, effectively improving energy utilization efficiency and reducing irreversible losses in the condensation process by at least 5%; by using two two-phase ejectors to pressurize and form three different pressure levels in the evaporators, irreversible losses in the evaporation process are reduced by at least 55%.

Description

Technical Field

[0001] This invention relates to the field of high-temperature heat pump system technology, specifically a mixed working fluid high-temperature heat pump system that combines gas-liquid separation and regulation technology, ejector pressurization technology, and multi-stage heat exchange. Background Technology

[0002] With the continuous rise in global energy demand, human dependence on fossil fuels has led to the serious challenge of global warming. The industrial sector, as a major energy consumer, accounts for 37% of global energy consumption. During industrial production, a large amount of heat is emitted as waste heat, which is particularly evident in oil processing, power plant cooling systems, mine drainage, and electroplating plants.

[0003] The emergence of high-temperature heat pump technology offers a solution to this problem. This technology, consuming minimal electrical energy, efficiently converts common low-grade heat sources found in production and daily life, such as wastewater, industrial waste cooling water, and natural water bodies, into higher-temperature heat energy. This heat energy can then be used for building heating or in various industrial processes, achieving efficient energy utilization. Therefore, this technology has enormous development potential and is expected to play a significant role in global energy transition and environmental protection.

[0004] Existing heat pump cycles mostly use pure working fluids. The isothermal characteristics of these working fluids during phase change lead to poor temperature matching between them and the variable-temperature heat source / cold source. This mismatch increases irreversible heat transfer losses during the cycle, thus reducing the heat pump's energy efficiency. Therefore, improving temperature matching in the heat transfer process and reducing irreversible heat transfer losses are key to improving heat pump energy efficiency. Using non-azeotropic mixed working fluids can improve the overall performance and flexibility of the system. Non-azeotropic mixed working fluids are mixtures composed of two or more pure working fluids with different boiling points (hereinafter collectively referred to as components). The advantages of non-azeotropic mixed working fluids can be summarized as follows: the variable-temperature phase change characteristics of non-azeotropic mixed working fluids, also known as temperature glide characteristics, can improve the temperature matching between the heat absorption and release processes and the heat / cold source in the heat pump cycle, reducing heat transfer losses and thus improving the system's energy efficiency. A drying and dehumidification method based on a non-azeotropic mixed working fluid heat pump system utilizes the advantages of this system. By precisely controlling the gas-liquid separation, heat exchange, and air circulation of the high-boiling-point and low-boiling-point working fluids, it achieves highly efficient and energy-saving drying and deep dehumidification. This method not only improves the energy utilization efficiency of the heat pump system but also meets the drying needs at different stages through flexible temperature and humidity control, demonstrating the application potential of non-azeotropic mixed working fluids in heat pump technology. However, the inventors have found that the potential of current non-azeotropic mixed working fluid heat pump systems is affected by the characteristics of the heat source and cold source. Once the heat pump cycle structure and working fluid are designed and determined, the system can only be passively adjusted to adapt to fluctuations in external operating conditions. Temperature matching during the heat exchange process is prone to deviation, resulting in limited performance improvement of the heat pump system. Therefore, the tendency for temperature matching to deviate under varying operating conditions limits the performance improvement of high-temperature heat pumps. Solving this problem could promote the rapid development of high-temperature heat pump technology.

[0005] Another method to improve temperature matching in the heat exchange process is to employ multi-stage heat exchange. Multi-stage heat exchange refers to dividing the heat exchange process into multiple stages in a heat pump system, each with its specific temperature and pressure conditions. This method can reduce heat loss caused by excessive temperature differences, thereby improving system performance. The core of a multi-stage condensing heat pump system for producing high-temperature hot water lies in its multi-stage heat exchange design, including a main working fluid circulation loop and working fluid branch loops. The main working fluid circulation loop sequentially includes an evaporator, compressor, vortex tube refrigerator, first heat exchanger, second heat exchanger, third heat exchanger, and expansion valve. The outlet of the vortex tube refrigerator is divided into two parts; a portion of the working fluid passes through the working fluid branch loops to the second and third heat exchangers, and then merges with the working fluid in the main circulation loop, achieving effective heat exchange. This multi-stage heat exchange design not only improves heat exchange efficiency but also produces high-temperature hot water up to boiling point, meeting the demand for high-temperature hot water in industries and other fields. However, the system has the following problems: its cold water heating process is a linear temperature change process, and its working fluid heat exchange process is an isothermal process. Therefore, the temperature curves of the working fluid and cold water are poorly matched, the irreversible heat exchange loss is large, and the improvement of the system's energy efficiency is limited. Summary of the Invention

[0006] To improve the energy efficiency of a mixed-working-refrigerant high-temperature heat pump system, enhance temperature matching during heat exchange, and reduce heat loss, this invention provides an adjustable multi-stage heat exchange jet mixed-working-refrigerant high-temperature heat pump system.

[0007] The mixed working fluid high-temperature heat pump system of the present invention includes: a mixed working fluid heat pump circulation loop and a gas-liquid jet water supply loop, wherein the two loops of the system are coupled to each other.

[0008] The mixed working fluid heat pump cycle includes a low-pressure stage compressor 1, a high-pressure stage compressor 11, the working fluid side of the first condenser 2, the working fluid side of the second condenser 3, the working fluid side of the third condenser 12, the working fluid side of the fourth condenser 13, the working fluid side of the first evaporator 6, the working fluid side of the second evaporator 8, the working fluid side of the third evaporator 10, a first gas-liquid separator 4, a second gas-liquid separator 14, a first two-phase ejector 7, and a second two-phase ejector 9.

[0009] The exhaust port of the low-pressure stage compressor 1 is connected to the working fluid inlet of the first condenser 2 and the suction port of the high-pressure stage compressor 11 via a three-way pipe.

[0010] The working fluid side outlet of the first condenser 2 is connected to the inlet of the first gas-liquid separator 4, the liquid outlet of the first gas-liquid separator 4 is connected to the working fluid inlet of the first two-phase ejector 7, and the gas outlet of the first gas-liquid separator 4 is connected to the working fluid side inlet of the second condenser 3.

[0011] The exhaust port of the high-pressure stage compressor 11 is connected to the working fluid side inlet of the third condenser 12, the working fluid side outlet of the third condenser 12 is connected to the inlet of the second gas-liquid separator 14, the liquid outlet of the second gas-liquid separator 14 is connected to the working fluid inlet of the second two-phase ejector 9, the gas outlet of the second gas-liquid separator 14 is connected to the working fluid side inlet of the fourth condenser 13, and the working fluid side outlet of the fourth condenser 13 is connected to the working fluid side outlet of the second condenser 3 and the inlet of the first throttle valve 5 respectively through a three-way pipe.

[0012] The outlet of the first throttle valve 5 is connected to the working fluid side inlet of the first evaporator 6, the working fluid side outlet of the first evaporator 6 is connected to the ejector fluid inlet of the first two-phase ejector 7, the outlet of the first two-phase ejector 7 is connected to the working fluid side inlet of the second evaporator 8, the working fluid side outlet of the second evaporator 8 is connected to the ejector fluid inlet of the second two-phase ejector 9, the outlet of the second two-phase ejector 9 is connected to the working fluid side inlet of the third evaporator 10, and the working fluid side outlet of the third evaporator 10 is connected to the suction port of the low-pressure stage compressor 1.

[0013] The gas-liquid jet water supply circuit includes a gas-liquid jet injector 16, a water pump 17, a water side of the first condenser 2, a water side of the second condenser 3, a water side of the third condenser 12, and a water side of the fourth condenser 13.

[0014] The ejector fluid inlet of the gas-liquid ejector 16 and the inlet of the water pump 17 are respectively connected to the two ports of the water inlet tee pipe; the outlet of the water pump 17 is connected to the working fluid inlet of the gas-liquid ejector 16 through the water side of the second condenser 3 and the water side of the first condenser 2 connected in series in sequence; the outlet of the gas-liquid ejector 16 is connected to the water side of the fourth condenser 13 and the water side of the third condenser 12 connected in series in sequence; the outlet of the water side of the third condenser 12 is the high-temperature steam outlet.

[0015] The working fluid inlet of the first two-phase ejector 7 and the working fluid inlet of the second two-phase ejector 9 are both high-pressure liquid working fluids, and the ejector fluid inlet of the first two-phase ejector 7 and the ejector fluid inlet of the second two-phase ejector 9 are both low-pressure gaseous working fluids; the working fluid inlet of the gas-liquid ejector 16 is a high-pressure gaseous working fluid, and the ejector fluid inlet of the gas-liquid ejector 16 is a low-pressure liquid working fluid.

[0016] During operation, the third port of the inlet tee is connected to the water supply pipe;

[0017] The other side of the first evaporator 6, the other side of the second evaporator 8, and the other side of the third evaporator 10, which are connected in series, are connected in series with the circulation pipe of the waste heat circulating water to be utilized; the working fluid side of the first evaporator 6, the working fluid side of the second evaporator 8, and the working fluid side of the third evaporator 10 achieve heat exchange with the circulation pipe of the waste heat circulating water to be utilized.

[0018] Further technical solutions are as follows:

[0019] The working fluid in the heat pump circulation loop is an environmentally friendly binary non-azeotropic mixture, prepared by uniformly mixing 40% by mass of cis-1,3,3,3-tetrafluoropropylene and 60% by mass of isopentane; the critical temperature of the environmentally friendly binary non-azeotropic mixture is 148.9°C. o C. The ozone depletion index is 0, the global warming potential is less than 10, and the temperature glide is 8.75°C per atmosphere. o C, the temperature glide at 2000 kPa is 6.58. o C, with a temperature glide of 4.3 at 3000 kPa. o C.

[0020] The water pump 17 is a booster pump.

[0021] The piping of the mixed working fluid high-temperature heat pump system is all insulated.

[0022] The beneficial technical effects of this invention are reflected in the following aspects:

[0023] The proposed adjustable multi-stage heat exchange jet-type high-temperature heat pump system uses a non-azeotropic mixed working fluid as the circulating working fluid, and combines two-stage compression, gas-liquid separation regulation, and ejector-enhanced stepped pressurization evaporation, which has the following advantages:

[0024] 1. The gas-liquid separator of this invention utilizes the different boiling points of the components in a non-azeotropic working fluid mixture to adjust the composition and alter the working fluid's properties. Simultaneously, it forms multi-stage condensation, increasing the temperature glide of the overall condensation process. See also... Figure 1 In the low-temperature condensation process, after the mixed working fluid is partially condensed in the first condenser 2, it enters the first gas-liquid separator 4 for gas-liquid separation and discharge of the liquid working fluid, thus adjusting the working fluid composition in the second condenser 3 and changing the temperature glide of the working fluid in the second condenser 3. Simultaneously, the temperature glide in the low-temperature condensation process is the superposition of the temperature glide of the working fluid in the first condenser 2 and the second condenser 3. Similarly, in the high-temperature condensation process, after the mixed working fluid is partially condensed, it passes through the second gas-liquid separator 14 for gas-liquid separation and discharge of the liquid working fluid, adjusting the working fluid composition in the fourth condenser 13 and changing the temperature glide of the working fluid in the fourth condenser 13. The temperature glide in the high-temperature condensation process is the superposition of the temperature glide of the working fluid in the third condenser 12 and the fourth condenser 33. Therefore, as... Figure 2 As shown, the temperature slip of the overall condensation process of the mixed working fluid high-temperature heat pump system is composed of the temperature slip of the working fluid in four sections of the first condenser 2, the second condenser 3, the third condenser 12 and the fourth condenser 13. The temperature curve of the working fluid is more closely matched with the temperature curve of the water supply, which greatly improves the temperature matching, reduces the irreversible loss of the condensation process by at least 5%, and effectively improves the energy utilization efficiency.

[0025] 2. Evaporation is achieved by pressurizing the evaporator using a two-phase ejector, resulting in three different pressure levels. See also... Figure 1 The working fluid, after being heated on the working fluid side of the first evaporator 6, enters the first two-phase ejector 7 for mixing, increasing the evaporation pressure and reducing the temperature difference between the working fluid and the waste heat circulating water. Then, the working fluid enters the second evaporator 8, is heated on the working fluid side, and enters the second two-phase ejector 9 for mixing, again increasing the evaporation pressure and further reducing the temperature difference between the working fluid and the waste heat circulating water. Figure 2 As shown, the overall evaporation process temperature curve of the mixed working fluid high-temperature heat pump system is sawtooth-shaped, and the temperature curve of the working fluid is more closely matched with the temperature curve of the waste heat circulating water, which effectively improves the temperature matching of the evaporation process and can reduce irreversible losses in the evaporation process by at least 55%.

[0026] 3. The water supply system uses a gas-liquid ejector 16 for mixing and pressurization, reducing pump power consumption. See also Figure 1In the gas-liquid jet water supply system, high-temperature water vapor from the water-side outlet of the second condenser 2 ejects low-pressure water. The gas-liquid ejector 16 utilizes the latent heat released by the condensation of high-temperature water vapor to convert it into pressure energy, which can increase the outlet pressure of the gas-liquid ejector without consuming mechanical work, making the outlet pressure more than twice the inlet pressure. At the same time, the three-way pipe diverts part of the water supply, reducing the water flow through the water pump 17, further reducing the power consumption of the water pump. Therefore, combining the gas-liquid ejector 16 with the water supply system can reduce the energy consumption of the water supply system and reduce pump power consumption by at least 91%. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the adjustable multi-stage heat exchange jet-type mixed working fluid high-temperature heat pump system of the present invention.

[0028] Figure 2 Temperature-heat load diagram for the heat exchange process of an adjustable multi-stage heat exchange jet-type mixed working fluid high-temperature heat pump system.

[0029] Figure 3 This is a schematic diagram of a two-phase injector.

[0030] Figure 4 This is a diagram showing the pressure variation along the flow direction inside a two-phase injector.

[0031] Figure 5 This is a schematic diagram of a gas-liquid ejector.

[0032] Figure 6 This is a diagram showing the pressure variation along the flow direction inside the gas-liquid ejector.

[0033] Figure 7 This is a temperature-heat load diagram for a multi-stage condensation process.

[0034] Figure 8 This is a temperature-heat load diagram for a multi-stage evaporation process.

[0035] Figure 9 This is a pressure-enthalpy diagram for a jet-type water supply system.

[0036] The numbers in the diagram above are: Low-pressure stage compressor 1, High-pressure stage compressor 11, First condenser 2, Second condenser 3, Third condenser 12, Fourth condenser 13, First evaporator 6, Second evaporator 8, Third evaporator 10, First gas-liquid separator 4, Second gas-liquid separator 14, First throttle valve 5, Second throttle valve 15, First two-phase ejector 7, Second two-phase ejector 9, Third gas-liquid ejector 16, Water pump 17. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0038] See Figure 1 An adjustable multi-stage heat exchange jet type mixed working fluid high-temperature heat pump system includes a mixed working fluid heat pump circulation loop and a gas-liquid jet type water supply loop.

[0039] The mixed working fluid heat pump cycle loop includes a low-pressure stage compressor 1, a high-pressure stage compressor 11, the working fluid side of the first condenser 2, the working fluid side of the second condenser 3, the working fluid side of the third condenser 12, the working fluid side of the fourth condenser 13, the working fluid side of the first evaporator 6, the working fluid side of the second evaporator 8, the working fluid side of the third evaporator 10, a first gas-liquid separator 4, a second gas-liquid separator 14, a first two-phase ejector 7, and a second two-phase ejector 9.

[0040] The exhaust port of the low-pressure stage compressor 1 is connected to the working fluid inlet of the first condenser 2 and the suction port of the high-pressure stage compressor 11 via a three-way pipe.

[0041] The working fluid side outlet of the first condenser 2 is connected to the inlet of the first gas-liquid separator 4, the liquid outlet of the first gas-liquid separator 4 is connected to the working fluid inlet of the first two-phase ejector 7, and the gas outlet of the first gas-liquid separator 4 is connected to the working fluid side inlet of the second condenser 3.

[0042] The exhaust port of the high-pressure stage compressor 11 is connected to the working fluid side inlet of the third condenser 12. The working fluid side outlet of the third condenser 12 is connected to the inlet of the second gas-liquid separator 14. The liquid outlet of the second gas-liquid separator 14 is connected to the working fluid inlet of the second two-phase ejector 9. The gas outlet of the second gas-liquid separator 14 is connected to the working fluid side inlet of the fourth condenser 13. The working fluid side outlet of the fourth condenser 13 is connected to the working fluid side outlet of the second condenser 3 and the inlet of the first throttle valve 5 respectively through a three-way pipe.

[0043] The outlet of the first throttle valve 5 is connected to the working fluid side inlet of the first evaporator 6. The working fluid side outlet of the first evaporator 6 is connected to the ejector fluid inlet of the first two-phase ejector 7. The outlet of the first two-phase ejector 7 is connected to the working fluid side inlet of the second evaporator 8. The working fluid side outlet of the second evaporator 8 is connected to the ejector fluid inlet of the second two-phase ejector 9. The outlet of the second two-phase ejector 9 is connected to the working fluid side inlet of the third evaporator 10. The working fluid side outlet of the third evaporator 10 is connected to the suction port of the low-pressure stage compressor 1.

[0044] The gas-liquid jet water supply circuit includes a gas-liquid jet injector 16, a water pump 17, the water side of the first condenser 2, the water side of the second condenser 3, the water side of the third condenser 12, and the water side of the fourth condenser 13. The water pump 17 is a booster pump.

[0045] The ejector fluid inlet of the gas-liquid ejector 16 and the inlet of the water pump 17 are respectively connected to the two ports of the water inlet tee; the outlet of the water pump 17 is connected to the working fluid inlet of the gas-liquid ejector 16 through the water side of the second condenser 3 and the water side of the first condenser 2 connected in series in sequence; the outlet of the gas-liquid ejector 16 is connected to the water side of the fourth condenser 13 and the water side of the third condenser 12 connected in series in sequence; the outlet of the water side of the third condenser 12 is the high-temperature steam outlet.

[0046] The working fluid inlet of the first two-phase ejector 7 and the working fluid inlet of the second two-phase ejector 9 are both high-pressure liquid working fluids, and the ejector fluid inlet of the first two-phase ejector 7 and the ejector fluid inlet of the second two-phase ejector 9 are both low-pressure gaseous working fluids; the working fluid inlet of the gas-liquid ejector 16 is a high-pressure gaseous working fluid, and the ejector fluid inlet of the gas-liquid ejector 16 is a low-pressure liquid working fluid.

[0047] During operation, the third port of the inlet tee is connected to the water supply pipe. The other side of the first evaporator 6, the other side of the second evaporator 8, and the other side of the third evaporator 10, which are connected in series, are connected in series with the circulation pipe for the waste heat circulating water.

[0048] The working fluid in the mixed-working-fluid heat pump circulation loop is an environmentally friendly binary non-azeotropic mixture, prepared by uniformly mixing 40% by mass of cis-1,3,3,3-tetrafluoropropylene and 60% by mass of isopentane; the critical temperature of the environmentally friendly binary non-azeotropic mixture is 148.9°C. o C. The ozone depletion index is 0, the global warming potential is less than 10, and the temperature glide is 8.75°C per atmosphere. o C, the temperature glide at 2000 kPa is 6.58. o C, with a temperature glide of 4.3 at 3000 kPa. o C.

[0049] All piping in the mixed working fluid high-temperature heat pump system is insulated.

[0050] The working principle of a high-temperature heat pump system with mixed working fluids is explained below:

[0051] During operation, the working fluid in the mixed working fluid heat pump circulation loop enters the low-pressure stage compressor 1 and is pressurized into medium-pressure superheated gas, which then enters two branches. Part of the medium-pressure superheated gas enters the first condenser 2 for partial condensation, becoming a two-phase state. The medium-pressure two-phase working fluid then enters the first gas-liquid separator 4 for gas-liquid separation. After separation, the high-boiling-point medium-pressure saturated liquid enters the working fluid inlet of the first two-phase ejector 7, while the low-boiling-point medium-pressure saturated gas enters the second condenser 3 for complete condensation into a liquid state. The other part of the medium-pressure superheated gas is further pressurized into high-pressure superheated gas in the high-pressure stage compressor 11 and then enters the third condenser 12 for partial condensation, becoming a two-phase state. The high-pressure two-phase working fluid enters the second gas-liquid separator 14 for gas-liquid separation. After separation, the high-boiling-point high-pressure saturated liquid enters the working fluid inlet of the second two-phase ejector 9, while the low-boiling-point high-pressure saturated gas enters the working fluid inlet of the second two-phase ejector 9. The gas enters the fourth condenser 13 and is completely condensed into a liquid state. The high-pressure liquid working fluid is depressurized by the second throttling valve 15 to become a two-phase fluid and mixes with the medium-pressure liquid working fluid at the outlet of the second condenser 3. Then, it is depressurized by the first throttling valve 5 and enters the first evaporator 6 to absorb heat and become a saturated gas state. It enters the ejector fluid inlet of the first two-phase ejector 7 and mixes with the saturated liquid working fluid at the working fluid inlet of the first two-phase ejector 7 to increase its pressure. It enters the second evaporator 8 through the outlet of the first two-phase ejector 7 to absorb heat and become a saturated gas state. It enters the ejector fluid inlet of the second two-phase ejector 9 and mixes with the saturated liquid working fluid at the working fluid inlet of the second two-phase ejector 9 to increase its pressure. It enters the third evaporator 10 through the outlet of the second two-phase ejector 9 to absorb heat and become a saturated gas state. Finally, it returns to the inlet of the low-pressure stage compressor 1 to complete the cycle.

[0052] In the gas-liquid jet water supply circuit, the water coming in from the water supply pipe is divided into two branches. One part of the low-pressure water is pressurized by the water pump 17 and enters the water side of the second condenser 3 and the water side of the first condenser 2 in sequence to absorb heat and become medium-pressure water vapor. It then enters the gas-liquid jet 16 through the working fluid inlet. The other part of the low-pressure water directly enters the gas-liquid jet 16 through the ejector fluid inlet. After being mixed and pressurized into a high-pressure fluid in the gas-liquid jet 16, it enters the fourth condenser 13 and the third condenser 12 in sequence to absorb heat and become high-pressure water vapor.

[0053] See Figure 3 The two-phase injector consists of a nozzle, a mixing chamber, and a diffusion chamber; the nozzle is a tapering type. See also... Figure 4 The working fluid inlet of the two-phase ejector is a high-pressure liquid working fluid, and the ejector fluid inlet is a low-pressure gaseous working fluid. The outlet pressure of the two-phase ejector is between the pressure of the working fluid inlet and the pressure of the ejector fluid inlet.

[0054] See Figure 5 The gas-liquid injector consists of a nozzle, a mixing chamber, and a diffusion chamber; the nozzle is a tapered-divergent type. (See also...) Figure 6The working fluid inlet is a high-pressure gaseous working fluid, and the ejector fluid inlet is a low-pressure liquid working fluid. After the two fluids mix, a condensation shock wave is formed at the end of the mixing chamber, causing a sudden pressure jump, which makes the outlet pressure of the gas-liquid ejector higher than the pressure at the working fluid inlet.

[0055] Taking the heating process of water at 101.325 kPa and 60°C to steam at 400 kPa and 150°C as an example, the working process of a high-temperature heat pump system with mixed working fluid is explained:

[0056] In the mixed working fluid heat pump circulation loop, the mixed working fluid, composed of cis-1,3,3,3-tetrafluoropropylene and isopentane with a mass ratio of 0.4:0.6, is pressurized to 1568.98 kPa by the low-pressure compressor 1 and then enters two branches. A portion of the gas enters the first condenser 2 for isobaric condensation and heat release, with the dryness set to 0.5. The working fluid partially condenses into a two-phase state and enters the first gas-liquid separator 4 for gas-liquid separation. In the first gas-liquid separator 4, the high-boiling-point liquid component of the two-phase working fluid has a higher density than the low-boiling-point gas component. At this point, the high-boiling-point liquid component (mass ratio 0.32:0.68) naturally settles to the lower layer, while the low-boiling-point gas component (mass ratio 0.48:0.52) floats on the upper layer. The high-boiling-point liquid component discharged from the first gas-liquid separator 4 enters the working fluid inlet of the first two-phase ejector 7, while the low-boiling-point gas component enters the second condenser 3 for isobaric condensation and heat release, completely condensing into a liquid state. Another portion of the working fluid is pressurized to a high-temperature, high-pressure gas of 2712.13 kPa by the high-pressure stage compressor 11, and then enters the third condenser 12 for isobaric condensation and heat release. The dryness is adjusted to 0.2. After the working fluid partially condenses into a two-phase state, it enters the second gas-liquid separator 14 for gas-liquid separation. In the second gas-liquid separator 14, the high-boiling-point liquid component of the two-phase working fluid has a higher density than the low-boiling-point gas component. The high-boiling-point liquid component with a mass ratio of 0.38:0.62 settles to the lower layer, while the low-boiling-point gas component with a mass ratio of 0.48:0.52 floats to the upper layer. The high-boiling-point liquid component discharged from the second gas-liquid separator 14 enters the working fluid inlet of the second two-phase ejector 9, while the low-boiling-point gas component enters the fourth condenser 13 for isobaric condensation and heat release. After completely condensing into a liquid state, it is depressurized to 1568.98 kPa through the second throttling valve 15, mixing with the working fluid from the inlet and outlet of the second condenser 3. After mixing, the working fluid is depressurized to 112 kPa through the first throttling valve 5. It then undergoes isobaric evaporation and heat absorption in the first evaporator 6, becoming gaseous. Next, it enters the working fluid inlet of the first two-phase ejector 7, where it mixes with the ejector fluid and is pressurized to 130.26 kPa. It then enters the second evaporator 8, where it undergoes isobaric evaporation and heat absorption again, becoming gaseous. The working fluid then enters the working fluid inlet of the second two-phase ejector 9, where it mixes with the ejector fluid and is pressurized to 187.66 kPa. Simultaneously, the mass ratio of the mixed working fluid is restored to 0.4:0.6. The pressurized working fluid then enters the third evaporator 10, where it undergoes isobaric evaporation and heat absorption again, becoming gaseous. Finally, it returns to the inlet of the low-pressure stage compressor 1, completing the entire cycle.

[0057] Depend on Figure 7As can be seen, the dashed line represents the water supply temperature curve of the gas-liquid jet water supply system, the dashed line represents the working fluid temperature curve of the unadjusted condensation process, and the dashed line represents the working fluid temperature curve of the adjusted condensation process. The area enclosed by the temperature curves of the circulating working fluid and water can represent irreversible losses. After adjustment, the final working fluid side outlet temperature of the second condenser 3 is 114.61℃, compared with the unadjusted medium-pressure condensation process working fluid side outlet temperature of 117.72℃, the overall temperature slip increased by 3.11℃, and the irreversible loss of the medium-pressure condensation process decreased by 2.79%; the working fluid side outlet temperature of the fourth condenser 3 is 146.18℃, compared with the unadjusted high-pressure condensation process working fluid side outlet temperature of 149.9℃, the overall temperature slip increased by 3.72℃, the irreversible loss of the condensation process decreased by 8.25%, and the overall irreversible loss of the condensation process decreased by 5%.

[0058] Depend on Figure 8 As can be seen, the dotted line represents the temperature curve of the waste heat circulating water, the dashed line represents the temperature curve of the working fluid in the unregulated evaporation process, and the dashed line represents the temperature curve of the working fluid in the regulated evaporation process. The area enclosed by the temperature curves of the circulating working fluid and the waste heat circulating water can characterize irreversible losses. For the evaporation process, the pressure of the first evaporator 6 is 112 kPa, and the outlet temperature is 20.49 kPa. o C, temperature glide is 1.36 o C; The pressure of the second evaporator 8 is 130.26 kPa, and the outlet temperature is 26.51℃. o C, temperature glide is 0.82 o C; The pressure of the third evaporator 10 is 187.66 kPa, and the outlet temperature is 53.07℃. o C, temperature glide is 15.24 o C, forming a three-segment sawtooth-shaped heat exchange temperature curve, compared to the unregulated evaporator working fluid side outlet (pressure 112 kPa, temperature 35.49°C). o C, temperature glide is 16.36 o C), the irreversible losses during the evaporation process were reduced by 55.06%.

[0059] Depend on Figure 9 As can be seen, the dashed line represents the saturation lines of the gas and liquid phases of water; the dashed line represents the pressure-enthalpy change of conventional water pump pressurization; the solid line represents the pressure-enthalpy change of the gas-liquid jet water supply system; and the dotted line illustrates the mixing process of the gas-liquid ejector. The inlet temperature of the conventional water pump pressurization system is 60°C. o C, with a pressure of 101.325 kPa, is pressurized to 400 kPa by a water pump and then subjected to isobaric evaporation, absorbing 150 kPa of heat. o For example, to produce 1000 kg of steam, the pump power consumption is 405.01 kW. In a gas-liquid jet water supply system, the water inlet temperature is 60°C. oC, with a pressure of 101.325 kPa, the water supply is divided into two branches via a three-way pipe, with a flow ratio of 1:1. One portion of the water supply is pressurized to 150 kPa by a water pump and enters the water side of the second condenser 3 and the first condenser 2 for isobaric heat absorption to saturate water vapor, before entering the working fluid inlet of the gas-liquid ejector 16. The other portion of the water supply directly enters the ejector fluid inlet of the gas-liquid ejector 16. The fluids from both branches mix in the gas-liquid ejector 16 to form a high-pressure fluid of 400 kPa, which then sequentially enters the fourth condenser 13 and the third condenser 12 to absorb heat to 150 kPa. o C. Water vapor. In the process of pressurizing and delivering water by the gas-liquid ejector, the pressure of the water pump is reduced by 250 kPa, and the water supply flow rate through the water pump is reduced by 50%. Taking the production of 1000 kg of water vapor as an example, the pump power consumption of the jet-type water supply system is only 33 kW, which can save 91.85% of the power consumption compared with the conventional pumping process.

[0060] Those skilled in the art will readily understand that the above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An adjustable multi-stage heat exchange jet type mixed working fluid high-temperature heat pump system, characterized in that: include: Mixed working fluid heat pump circulation loop and gas-liquid jet water supply loop; The mixed working fluid heat pump circulation loop includes a low-pressure stage compressor (1), a high-pressure stage compressor (11), the working fluid side of the first condenser (2), the working fluid side of the second condenser (3), the working fluid side of the third condenser (12), the working fluid side of the fourth condenser (13), the working fluid side of the first evaporator (6), the working fluid side of the second evaporator (8), the working fluid side of the third evaporator (10), the first gas-liquid separator (4), the second gas-liquid separator (14), the first two-phase ejector (7), and the second two-phase ejector (9). The exhaust port of the low-pressure stage compressor (1) is connected to the working fluid inlet of the first condenser (2) and the suction port of the high-pressure stage compressor (11) respectively through a three-way pipe; The working fluid side outlet of the first condenser (2) is connected to the inlet of the first gas-liquid separator (4), the liquid outlet of the first gas-liquid separator (4) is connected to the working fluid inlet of the first two-phase ejector (7), and the gas outlet of the first gas-liquid separator (4) is connected to the working fluid side inlet of the second condenser (3). The exhaust port of the high-pressure stage compressor (11) is connected to the working fluid side inlet of the third condenser (12), the working fluid side outlet of the third condenser (12) is connected to the inlet of the second gas-liquid separator (14), the liquid outlet of the second gas-liquid separator (14) is connected to the working fluid inlet of the second two-phase ejector (9), the gas outlet of the second gas-liquid separator (14) is connected to the working fluid side inlet of the fourth condenser (13), and the working fluid side outlet of the fourth condenser (13) is connected to the working fluid side outlet of the second condenser (3) and the inlet of the first throttle valve (5) respectively through a three-way pipe; The outlet of the first throttle valve (5) is connected to the working fluid side inlet of the first evaporator (6), the working fluid side outlet of the first evaporator (6) is connected to the ejector fluid inlet of the first two-phase ejector (7), the outlet of the first two-phase ejector (7) is connected to the working fluid side inlet of the second evaporator (8), the working fluid side outlet of the second evaporator (8) is connected to the ejector fluid inlet of the second two-phase ejector (9), the outlet of the second two-phase ejector (9) is connected to the working fluid side inlet of the third evaporator (10), and the working fluid side outlet of the third evaporator (10) is connected to the suction port of the low-pressure stage compressor (1). The gas-liquid jet water supply circuit includes a gas-liquid jet injector (16), a water pump (17), the water side of the first condenser (2), the water side of the second condenser (3), the water side of the third condenser (12), and the water side of the fourth condenser (13). The ejector fluid inlet of the gas-liquid ejector (16) and the inlet of the water pump (17) are respectively connected to the two ports of the water inlet tee; the outlet of the water pump (17) is connected to the working fluid inlet of the gas-liquid ejector (16) through the water side of the second condenser (3) and the water side of the first condenser (2) in series; the outlet of the gas-liquid ejector (16) is connected to the water side of the fourth condenser (13) and the water side of the third condenser (12) in series; the outlet of the water side of the third condenser (12) is the high temperature steam outlet. The working fluid inlet of the first two-phase ejector (7) and the working fluid inlet of the second two-phase ejector (9) are both high-pressure liquid working fluids, and the ejector fluid inlet of the first two-phase ejector (7) and the ejector fluid inlet of the second two-phase ejector (9) are both low-pressure gaseous working fluids; the working fluid inlet of the gas-liquid ejector (16) is a high-pressure gaseous working fluid, and the ejector fluid inlet of the gas-liquid ejector (16) is a low-pressure liquid working fluid; During operation, the third port of the inlet tee is connected to the water supply pipe; The other side of the first evaporator (6), the other side of the second evaporator (8), and the other side of the third evaporator (10) are connected in series with the circulation pipe of the waste heat circulating water to be utilized; the working fluid side of the first evaporator (6), the working fluid side of the second evaporator (8), and the working fluid side of the third evaporator (10) exchange heat with the circulation pipe of the waste heat circulating water to be utilized.

2. The adjustable multi-stage heat exchange jet type mixed working fluid high-temperature heat pump system according to claim 1, characterized in that: The working fluid in the heat pump circulation loop is an environmentally friendly binary non-azeotropic mixture, prepared by uniformly mixing 40% by mass of cis-1,3,3,3-tetrafluoropropylene and 60% by mass of isopentane; the critical temperature of the environmentally friendly binary non-azeotropic mixture is 148.9°C. o C. The ozone depletion index is 0, the global warming potential is less than 10, and the temperature glide is 8.75°C per atmosphere. o C, the temperature glide at 2000 kPa is 6.

58. o C, with a temperature glide of 4.3 at 3000 kPa. o C.

3. The adjustable multi-stage heat exchange jet type mixed working fluid high-temperature heat pump system according to claim 1, characterized in that: The water pump (17) is a booster pump.

4. The adjustable multi-stage heat exchange jet type mixed working fluid high-temperature heat pump system according to claim 1, characterized in that: The piping of the mixed working fluid high-temperature heat pump system is all insulated.

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