A cryogenic step-by-step production unit and process based on ejector condensation and enhanced heat absorption

Abstract

The application discloses a deep cooling step-by-step production unit and process based on ejector condensation and enhanced heat absorption in the technical field of absorption refrigeration, which comprises a generation assembly, an evaporation absorption assembly, an ejector assembly and a condenser; the evaporation absorption assembly comprises a medium-pressure evaporator, a low-pressure evaporator, a medium-pressure absorber and a low-pressure absorber; the generation assembly uses a heat source to produce a cold source, the medium-pressure evaporator uses part of the cold source produced by the generation assembly to preliminarily cool the heat carrier, and the low-pressure evaporator uses the remaining cold source discharged by the medium-pressure evaporator to cool the heat carrier again; the condenser produces cold energy to be used as the cold source of the medium-pressure absorber and the low-pressure absorber; the absorption refrigeration unit is optimally designed, step-by-step refrigeration is used to replace single-stage refrigeration, the problem that the cost is excessively high due to excessively large equipment in single-stage refrigeration is solved, and the use of the unit in deep cooling production scenes is further expanded.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of absorption refrigeration, in particular to a deep cooling step-by-step production unit and process based on ejector condensation and enhanced heat absorption. BACKGROUND

[0002] The absorption refrigeration unit is driven by low-grade waste heat to use thermal working medium to carry out refrigeration through phase change of the working medium (such as ammonia); specifically, low-grade waste heat is used to heat in the generator, and the mixed solution (rich solution) rich in refrigerant with a certain concentration transported from the absorber by the solution pump is used to make most of the low-boiling-point refrigerant in the rich solution desorb to become high-pressure gaseous refrigerant entering the condenser to be cooled into high-pressure liquid refrigerant by circulating water, and the high-pressure liquid refrigerant is reduced in pressure by the expansion valve to become low-pressure liquid refrigerant, and the low-pressure liquid refrigerant enters the evaporator to vaporize into low-pressure gaseous refrigerant by absorbing heat of the medium (cooling medium) to be cooled, and the low-pressure gaseous refrigerant enters the absorber; the remaining high-pressure lean solution in the generator is reduced in pressure by the pressure reducing valve to become low-pressure lean solution, and enters the absorber to mix and absorb the low-pressure gaseous refrigerant from the evaporator to restore to the original concentration to become normal-temperature rich solution, and the normal-temperature rich solution is sent into the generator by the solution pump to continue the circulation work after being increased in pressure; the circulating water is first used to cool the solution in the absorber, and then used to cool the condenser.

[0003] The refrigeration gradient of the above refrigeration unit is single-stage, and when deep cooling is produced, the heat exchange area required by the single unit is large, resulting in a large equipment volume, which causes great difficulty in manufacturing, processing, transportation and hoisting of the unit, and thus the cost of putting the unit into operation is high, which limits the use of the unit in the deep cooling scene.

[0004] The circulating water is used as the cold source of the absorber, and the temperature and heat absorption efficiency of the circulating water directly affect the refrigeration efficiency of the unit, and the heat absorption of the circulating water belongs to sensible heat temperature rise without phase change, so the heat absorption efficiency is limited; the circulating water temperature is affected by the wet-bulb temperature, and in summer, the wet-bulb temperature is high, so the limiting temperature of the circulating water cooled by the air cooling tower is limited, and thus the circulating water temperature is high, and the high circulating water temperature will cause the unit to have low efficiency when producing deep cooling. SUMMARY

[0005] The present application provides a deep cooling step-by-step production unit and process based on ejector condensation and enhanced heat absorption, which solves the problems existing in the prior art absorption refrigeration unit.

[0006] The present application achieves the above-mentioned purpose by the following technical scheme: a deep cooling step-by-step production unit and process based on ejector condensation and enhanced heat absorption, comprising: a generator assembly, an evaporation and absorption assembly, an ejector assembly and a condenser.

[0007] The evaporation-absorption assembly comprises a medium-pressure evaporator, a low-pressure evaporator, a medium-pressure absorber and a low-pressure absorber.

[0008] The generating assembly generates cold source by using heat source, the medium-pressure evaporator preliminarily cools the carrier refrigerant by using part of the cold source generated by the generating assembly, and the low-pressure evaporator further cools the carrier refrigerant by using the remaining cold source discharged by the medium-pressure evaporator.

[0009] The condenser generates cold energy to be used as the cold source of the medium-pressure absorber and the low-pressure absorber, and the ejector assembly uses the cold source after being used by the medium-pressure absorber to eject the cold source after being used by the low-pressure absorber, and uses the gaseous refrigerant generated by the generating assembly to eject into the condenser for generating cold energy.

[0010] Preferably, the generating assembly comprises a high-pressure generator and a sub-high-pressure generator.

[0011] The high-pressure generator heats the sub-rich liquid delivered by the sub-high-pressure generator by using heat source, so that the sub-rich liquid forms lean liquid and gaseous refrigerant, the sub-high-pressure generator heats the rich liquid by using the gaseous refrigerant generated by the high-pressure generator as heat source, so that the rich liquid forms sub-rich liquid and gaseous refrigerant, the gaseous refrigerant generated by the sub-high-pressure generator is used as the ejecting source of the ejector assembly, and the gaseous refrigerant generated by the high-pressure generator is used as the cold source of the medium-pressure evaporator and the low-pressure evaporator after being heated by the sub-high-pressure generator.

[0012] Preferably, the generating assembly further comprises a booster, which is used to boost the sub-rich liquid inputted by the sub-high-pressure generator into the high-pressure generator.

[0013] Preferably, the ejector assembly comprises a first ejector and a second ejector, the second ejector uses the cold source after being used by the medium-pressure absorber to eject the cold source after being used by the low-pressure absorber, and the first ejector uses the gaseous refrigerant generated by the sub-high-pressure generator to eject the cold source after being used by the second ejector.

[0014] Preferably, the evaporation-absorption assembly further comprises a first solution pump and a second expansion valve.

[0015] The deep cooling step-by-step generating set further comprises a second solution pump, a first expansion valve, a third expansion valve and a pressure reducer, the second solution pump is used to boost the rich liquid inputted by the medium-pressure absorber into the sub-high-pressure generator, the first expansion valve is used to reduce the pressure of the cold source inputted by the sub-high-pressure generator into the medium-pressure evaporator, the third expansion valve is used to reduce the pressure of the cold source inputted by the condenser into the low-pressure absorber, and the pressure reducer is used to reduce the pressure of the lean liquid inputted by the high-pressure generator into the low-pressure absorber.

[0016] Preferably, the booster and the pressure reducer are both vane turbine boosters, and the two vane turbine boosters are linked through a transmission shaft.

[0017] Preferably, a composite generator is used instead of the high-pressure generator and the sub-high-pressure generator, and a composite evaporation absorber is used instead of the medium-pressure evaporator, the low-pressure evaporator, the medium-pressure absorber and the low-pressure absorber, both of which are fixed tube sheet heat exchangers with a main structure composed of a head, a tube box cylinder section, a tube sheet, heat exchange tubes and a shell, the composite generator is divided into a high-pressure generation cavity and a sub-high-pressure generation cavity, and the composite evaporation absorber is divided into a low-pressure evaporation cavity, a low-pressure absorption cavity, a medium-pressure absorption cavity and a medium-pressure evaporation cavity.

[0018] Preferably, the high-pressure generation cavity and the sub-high-pressure generation cavity are separated by a first partition plate, and the low-pressure evaporation cavity, the low-pressure absorption cavity, the medium-pressure absorption cavity and the medium-pressure evaporation cavity are separated by a second partition plate.

[0019] Preferably, a deep cooling step-by-step production process based on ejector condensation and enhanced heat absorption uses the above-mentioned deep cooling step-by-step production unit based on ejector condensation and enhanced heat absorption, including the following steps:

[0020] The high-pressure generation cavity uses a heat source to heat the sub-rich liquid delivered by the sub-high-pressure generation cavity to produce gaseous refrigerant, the sub-high-pressure generation cavity uses the gaseous refrigerant produced by the high-pressure generation cavity as a heat source to heat the rich liquid, so that the rich liquid forms sub-rich liquid and gaseous refrigerant, and the gaseous refrigerant produced by the high-pressure generation cavity is used as a cold source to first enter the medium-pressure evaporation cavity to preliminarily cool the carrier refrigerant therein, and the remaining cold source enters the low-pressure evaporation cavity to further cool the carrier refrigerant introduced by the medium-pressure evaporation cavity;

[0021] The condenser produces cold energy to be used as a cold source for the medium-pressure absorption cavity and the low-pressure absorption cavity, the second ejector uses the cold source after being used in the medium-pressure absorption cavity to eject the cold source after being used in the low-pressure absorption cavity, and the first ejector uses the gaseous refrigerant produced by the sub-high-pressure generation cavity to eject the cold source after being used in the second ejector and enters the condenser to produce cold energy;

[0022] A deep cooling step-by-step production process based on ejector condensation and enhanced heat absorption also uses the above-mentioned deep cooling step-by-step production unit based on ejector condensation and enhanced heat absorption, including the following steps:

[0023] The high-pressure generator uses a heat source to heat the sub-rich liquid delivered by the sub-high-pressure generator to produce gaseous refrigerant, the sub-high-pressure generator uses the gaseous refrigerant produced by the high-pressure generator as a heat source to heat the rich liquid, so that the rich liquid forms sub-rich liquid and gaseous refrigerant, and the gaseous refrigerant produced by the high-pressure generator is used as a cold source to first enter the medium-pressure evaporator to preliminarily cool the carrier refrigerant therein, and the remaining cold source enters the low-pressure evaporator to further cool the carrier refrigerant introduced by the medium-pressure evaporator;

[0024] The condenser produces cold energy, which is used as the cold source of the medium-pressure absorber and the low-pressure absorber respectively, the second ejector uses the cold source after the medium-pressure absorber to eject the cold source after the low-pressure absorber, the first ejector uses the gaseous refrigerant produced by the sub-high-pressure generator to eject the used cold source in the second ejector, and enters the condenser to produce cold energy.

[0025] The present application has the advantages of:

[0026] 1. The absorption refrigeration unit is optimally designed, and the single-stage refrigeration is replaced by the step-by-step refrigeration, so that the problem of high cost caused by oversized equipment in single-stage refrigeration is solved, and the use of the unit in deep cooling scene is further expanded.

[0027] 2. The medium-pressure liquid refrigerant condensed in the condenser is used as the cold source of the medium-pressure absorber and the low-pressure absorber, which replaces the circulating water. The heat absorption in the absorber tube produces flow boiling and phase change, greatly improves the efficiency of heat transfer, and the medium-pressure liquid refrigerant is self-produced by the unit, the temperature is stable, and the influence of high temperature in summer is very small. The low-temperature liquid refrigerant can maintain high operating efficiency when the unit produces deep cooling.

[0028] 3. The step-by-step ejection by the two ejectors can improve the absorption efficiency of the medium-pressure absorber and the low-pressure absorber, and further improve the refrigeration efficiency of the unit.

[0029] 4. The impeller turbine supercharger is used to replace the solution pump and the pressure reducing valve respectively, the pressure of the high-pressure lean liquid is used to supercharge the sub-high-pressure rich liquid, the energy loss of the original throttling is converted into the pressure energy of the high-pressure lean liquid, the internal energy of the unit is deeply utilized, and the COP of the unit is improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is a structure schematic diagram of the deep cooling step-by-step production unit of the present application.

[0031] Figure 2 It is a connection structure schematic diagram of the composite generator and the composite evaporation absorber in the deep cooling step-by-step production unit of the present application.

[0032] Figure 3 It is a connection structure schematic diagram of the composite generator and the composite evaporation absorber of the present application.

[0033] Figure 4 It is a connection structure schematic diagram of the composite generator and the composite evaporation absorber of the present application. Figure 3 It is a schematic diagram of the present application.

[0034] Figure 5 It is a connection structure schematic diagram of the supercharger and the pressure reducer of the present application.

[0035] In the figure: 1, high-pressure generator; 2, sub-high-pressure generator; 3, first ejector; 4, second solution pump; 5, first expansion valve; 6, condenser; 7, booster; 8, medium-pressure evaporator; 9, low-pressure evaporator; 10, medium-pressure absorber; 11, low-pressure absorber; 12, first solution pump; 13, second expansion valve; 14, third expansion valve; 15, second ejector; 16, pressure reducer; 17, compound generator; 171, high-pressure generation cavity; 172, sub-high-pressure generation cavity; 173, first partition; 18, compound evaporative absorber; 181, low-pressure evaporation cavity; 182, low-pressure absorption cavity; 183, medium-pressure absorption cavity; 184, medium-pressure evaporation cavity; 185, second partition; 19, transmission shaft. DETAILED DESCRIPTION

[0036] The following detailed description of the application is made with reference to the accompanying drawings, it is necessary to point out here that the following detailed description is only used to further illustrate the application, and cannot be understood as limiting the scope of protection of the application, and those skilled in the art can make some non-essential improvements and adjustments to the application according to the above application content.

[0037] Example 1

[0038] Please refer to Figure 1 , a deep cooling step-by-step production unit based on ejector condensation and enhanced heat absorption, comprising: a generation assembly, an evaporation and absorption assembly, an ejector assembly and a condenser 6; the evaporation and absorption assembly comprises a medium-pressure evaporator 8, a low-pressure evaporator 9, a medium-pressure absorber 10 and a low-pressure absorber 11.

[0039] It should be noted that the generation assembly uses a heat source to produce a cold source, the medium-pressure evaporator 8 uses part of the cold source produced by the generation assembly to preliminarily cool the heat carrier, the low-pressure evaporator 9 uses the remaining cold source discharged by the medium-pressure evaporator 8 to cool the heat carrier again, thereby realizing the gradual cooling of the heat carrier; the condenser 6 produces cold energy to be used as the cold source of the medium-pressure absorber 10 and the low-pressure absorber 11, and the ejector assembly uses the cold source used by the medium-pressure absorber 10 to eject the cold source used by the low-pressure absorber 11 and uses gaseous refrigerant produced by the generation assembly to be injected into the condenser 6 for producing cold energy.

[0040] In this embodiment, as a further optimized scheme, please refer to Figure 1 , the generation assembly comprises a high-pressure generator 1 and a sub-high-pressure generator 2; the ejector assembly comprises a first ejector 3 and a second ejector 15; the evaporation and absorption assembly further comprises a first solution pump 12 and a second expansion valve 13; the deep cooling step-by-step production unit further comprises a second solution pump 4, a first expansion valve 5, a third expansion valve 14 and a pressure reducer 16;

[0041] The high-pressure generator 1 is communicated with the secondary high-pressure generator 2 through the booster 7, the high-pressure gaseous refrigerant outlet of the high-pressure generator 1 is communicated with the high-pressure gaseous refrigerant inlet of the secondary high-pressure generator 2, and the high-pressure lean liquid outlet of the high-pressure generator 1 is communicated with the low-pressure lean liquid inlet of the low-pressure absorber 11 through the pressure reducer 16; the secondary high-pressure generator 2 is communicated with the medium-pressure absorber 10 through the second solution pump 4, the high-pressure liquid refrigerant outlet of the secondary high-pressure generator 2 is communicated with the medium-pressure liquid refrigerant inlet of the medium-pressure evaporator 8 through the first expansion valve 5, the secondary high-pressure gaseous refrigerant outlet of the secondary high-pressure generator 2 is communicated with the first ejector 3; the outlet of the first ejector 3 is communicated with the medium-pressure gaseous refrigerant inlet of the condenser 6, the medium-pressure liquid refrigerant outlet of the condenser 6 is divided into two paths, one path is communicated with the low-pressure liquid refrigerant inlet of the low-pressure absorber 11 through the third expansion valve 14, and the other path is communicated with the medium-pressure liquid refrigerant inlet of the medium-pressure absorber 10; the medium-pressure liquid refrigerant outlet of the medium-pressure evaporator 8 is communicated with the low-pressure liquid refrigerant inlet of the low-pressure evaporator 9 through the second expansion valve 13, the medium-pressure gaseous refrigerant outlet of the medium-pressure evaporator 8 is communicated with the medium-pressure gaseous refrigerant inlet of the medium-pressure absorber 10, and the medium-pressure liquid refrigerant outlet of the medium-pressure evaporator 8 is communicated with the medium-pressure liquid refrigerant inlet of the medium-pressure absorber 10; the low-pressure gaseous refrigerant outlet of the low-pressure evaporator 9 is communicated with the low-pressure gaseous refrigerant inlet of the low-pressure absorber 11; the low-pressure lean liquid outlet of the low-pressure absorber 11 is communicated with the medium-pressure lean liquid inlet of the medium-pressure absorber 10 through the first solution pump 12; the medium-pressure gaseous refrigerant outlet of the medium-pressure absorber 10 and the low-pressure gaseous refrigerant outlet of the low-pressure absorber 11 are both communicated with the inlet of the second ejector 15, and the outlet of the second ejector 15 is communicated with the inlet of the first ejector 3.

[0042] It should be noted that the deep cooling step-by-step production process based on ejector condensation and enhanced heat absorption comprises the following steps:

[0043] The heat source heats the high-pressure lean liquid transported from the secondary high-pressure generator 2 by the booster 7 in the high-pressure generator 1, so that most of the low-boiling-point refrigerants in the high-pressure lean liquid are desorbed to become high-pressure gaseous refrigerants; the high-pressure gaseous refrigerants enter the secondary high-pressure generator 2 as a heat source, heat the secondary high-pressure rich liquid transported from the medium-pressure absorber 10 by the second solution pump 4, so that part of the low-boiling-point refrigerants in the secondary high-pressure rich liquid are desorbed to become secondary high-pressure gaseous refrigerants, and the secondary high-pressure gaseous refrigerants enter the first ejector 3 as an injection source;

[0044] The high-pressure gaseous refrigerant entering the sub-high pressure generator 2 is condensed into high-pressure liquid refrigerant by heat absorption, and then is depressurized into medium-pressure liquid refrigerant by the first expansion valve 5; the medium-pressure liquid refrigerant enters the medium-pressure evaporator 8, a part of which is gasified into medium-pressure gaseous refrigerant by absorbing the heat of the carrier coolant as the cold source of primary refrigeration, and then enters the medium-pressure absorber 10; the remaining medium-pressure liquid refrigerant is depressurized into low-pressure liquid refrigerant by the second expansion valve 13, enters the low-pressure evaporator 9 as the cold source of deep refrigeration, and is gasified into low-pressure gaseous refrigerant by absorbing the heat of the carrier coolant from the medium-pressure evaporator 8, and then enters the low-pressure absorber 11; in this process, the carrier coolant is gradually cooled, thereby completing the deep cooling process;

[0045] The sub-high-pressure gaseous refrigerant enters the first ejector 3, and is gasified into medium-pressure gaseous refrigerant by ejecting the sub-medium-pressure gaseous refrigerant from the second ejector 15; the medium-pressure gaseous refrigerant enters the condenser 6, and is cooled into medium-pressure liquid refrigerant by circulating water, and the medium-pressure liquid refrigerant is divided into two paths, one of which enters the medium-pressure absorber 10 as the cold source of the absorption process of the medium-pressure absorber 10, and the other of which is depressurized into low-pressure liquid refrigerant by the third expansion valve 14, and then enters the low-pressure absorber 11 as the cold source of the absorption process of the low-pressure absorber 11;

[0046] The remaining high-pressure lean liquid from the high-pressure generator 1 is depressurized into low-pressure lean liquid by the pressure reducer 16, and then enters the low-pressure absorber 11, and is mixed with the low-pressure gaseous refrigerant from the low-pressure evaporator 9 as the cold source of refrigeration for the carrier coolant to become low-pressure sub-rich liquid; the heat released in the absorption process is absorbed by the low-pressure liquid refrigerant (the cold source discharged from the condenser 6) entering the low-pressure absorber 11, and the low-pressure liquid refrigerant is gasified into low-pressure gaseous refrigerant, which is then ejected into the second ejector 15; the low-pressure sub-rich liquid is pressurized into medium-pressure sub-rich liquid by the first solution pump 12, and then enters the medium-pressure absorber 10, and is mixed with the medium-pressure gaseous refrigerant from the medium-pressure evaporator 8 as the cold source of refrigeration for the carrier coolant to become medium-pressure rich liquid; the heat released in the absorption process is absorbed by the medium-pressure liquid refrigerant (the cold source discharged from the condenser 6) entering the medium-pressure absorber 10, and the medium-pressure liquid refrigerant is gasified into medium-pressure gaseous refrigerant;

[0047] The medium-pressure gaseous refrigerant enters the second ejector 15 as the ejecting source, and is gasified into sub-medium-pressure gaseous refrigerant by ejecting the low-pressure gaseous refrigerant from the low-pressure absorber 11, and then is re-ejected into the first ejector 3 by the sub-high-pressure gaseous refrigerant from the sub-high pressure generator 2 to become medium-pressure gaseous refrigerant, which enters the condenser 6, is cooled into medium-pressure liquid refrigerant by circulating water, and continues the subsequent circulation;

[0048] The medium pressure rich solution formed in the medium pressure absorber 10 is pressurized to a sub-high pressure rich solution by the second solution pump 4, and the sub-high pressure rich solution enters the sub-high pressure generator 2 to continue the following cycle.

[0049] In this embodiment, as a further optimized scheme, please refer to Figure 1 and Figure 5 , the booster 7 can be a solution pump, and the pressure reducer 16 can be a pressure reducing valve; the booster 7 and the pressure reducer 16 can also be both impeller turbo boosters (including a shell and an impeller arranged inside the shell), and the two impellers are linked through a transmission shaft 19; the high pressure lean solution discharged from the high pressure generator 1 enters one impeller turbo booster to drive the impeller in the impeller turbo booster to rotate (in this process, the high pressure lean solution is reduced in pressure), and the transmission shaft 19 is driven to make the impeller in the other impeller turbo booster rotate to pressurize the sub-high pressure lean solution discharged from the sub-high pressure generator 2; the pressure of the high pressure lean solution is used to pressurize the sub-high pressure lean solution, thereby realizing deep utilization of energy inside the unit.

[0050] Embodiment 2

[0051] As a further optimized scheme of embodiment 1, please refer to Figure 2 , Figure 3 and Figure 4 , the composite generator 17 is used instead of the high pressure generator 1 and the sub-high pressure generator 2, and the composite evaporation absorber 18 is used instead of the medium pressure evaporator 8, the low pressure evaporator 9, the medium pressure absorber 10 and the low pressure absorber 11; the composite generator 17 and the composite evaporation absorber 18 are both fixed tube sheet heat exchangers whose main structures are composed of a head, a tube box cylinder section, a tube sheet, heat exchange tubes and a shell; the left and right heads and the tube box cylinder section are respectively welded and fixed on the left and right tube sheets; the shell is welded and fixed between the left and right tube sheets; and the heat exchange tubes are welded and fixed on the left and right tube sheets.

[0052] Among them, the first partition plate 173 is arranged in the inner cavity of the composite generator 17, the first partition plate 173 is in the form of a straight line, the first partition plate 173 is coated with an insulating layer outside, and the first partition plate 173 is used to divide the inner cavity of the composite generator 17 into a high pressure generation cavity 171 and a sub-high pressure generation cavity 172; the sub-high pressure generation cavity 172 is located above the high pressure generation cavity 171.

[0053] The shell of the low-pressure generating cavity 172 is provided with a spray assembly (including a spray pipe and a spray head), and the shell of the low-pressure generating cavity 172 is provided with a low-pressure rich-liquid inlet, a low-pressure gaseous refrigerant outlet and a low-pressure secondary rich-liquid outlet. The low-pressure rich-liquid inlet is communicated with the spray pipe and the second solution pump 4 through a pipeline. The low-pressure gaseous refrigerant outlet is communicated with the inlet of the first ejector 3 through a pipeline. The low-pressure secondary rich-liquid outlet is communicated with the inlet of the booster 7 through a pipeline. The left and right tube boxes of the low-pressure generating cavity 172 are respectively provided with a high-pressure gaseous refrigerant inlet and a high-pressure liquid refrigerant outlet. The high-pressure liquid refrigerant outlet is communicated with the first expansion valve 5 through a pipeline;

[0054] The shell of the high-pressure generating cavity 171 is provided with a spray assembly (including a spray pipe and a spray head), and the shell of the high-pressure generating cavity 171 is provided with a high-pressure secondary rich-liquid inlet, a high-pressure gaseous refrigerant outlet and a high-pressure lean-liquid outlet. The high-pressure secondary rich-liquid inlet is communicated with the spray pipe and the outlet of the booster 7 through a pipeline. The high-pressure gaseous refrigerant outlet is communicated with the high-pressure gaseous refrigerant inlet on the left tube box of the low-pressure generating cavity 172 through a pipeline. The high-pressure lean-liquid outlet is communicated with the inlet of the pressure reducer 16 through a pipeline. The left and right tube boxes of the high-pressure generating cavity 171 are respectively provided with a heat source inlet and outlet.

[0055] The inner cavity of the composite evaporation absorber 18 is provided with a second partition plate 185. The second partition plate 185 is in a cross shape, and an insulating layer is coated outside the second partition plate 185. The second partition plate 185 is used to divide the inner cavity of the composite evaporation absorber 18 into a low-pressure evaporation cavity 181, a low-pressure absorption cavity 182, a medium-pressure absorption cavity 183 and a medium-pressure evaporation cavity 184.

[0056] The shell of the low-pressure evaporation cavity 181 is provided with a spray assembly (including a spray pipe and a spray head), and the shell of the low-pressure evaporation cavity 181 is provided with a low-pressure liquid refrigerant inlet. The low-pressure liquid refrigerant inlet is communicated with the spray pipe and the second expansion valve 13 through a pipeline. The left and right tube boxes of the low-pressure evaporation cavity 181 are respectively provided with a coolant outlet and an inlet.

[0057] The shell of the low-pressure absorption cavity 182 is provided with a spray assembly (including a spray pipe and a spray head), and the shell of the low-pressure absorption cavity 182 is provided with a low-pressure lean-liquid inlet and a low-pressure secondary rich-liquid outlet. The low-pressure lean-liquid inlet is communicated with the spray pipe and the pressure reducer 16 through a pipeline. The low-pressure secondary rich-liquid outlet is communicated with the first solution pump 12 through a pipeline. The left and right tube boxes of the low-pressure absorption cavity 182 are respectively provided with a low-pressure liquid refrigerant inlet and a low-pressure gaseous refrigerant outlet. The low-pressure liquid refrigerant inlet is communicated with the third expansion valve 14 through a pipeline. The low-pressure gaseous refrigerant outlet is communicated with the inlet of the second ejector 15 through a pipeline.

[0058] A spray assembly (including a spray pipe and a spray head) is arranged in the shell of the medium-pressure absorption cavity 183. A medium-pressure sub-rich liquid inlet and a medium-pressure rich liquid outlet are arranged on the shell of the medium-pressure absorption cavity 183. The medium-pressure sub-rich liquid inlet is communicated with the spray pipe and the first solution pump 12 through a pipeline. The medium-pressure rich liquid outlet is communicated with the second solution pump 4 through a pipeline. The left and right tube boxes of the medium-pressure absorption cavity 183 are respectively provided with a medium-pressure liquid refrigerant inlet and a medium-pressure gaseous refrigerant outlet. The medium-pressure liquid refrigerant inlet is communicated with the condenser 6 through a pipeline. The medium-pressure gaseous refrigerant outlet is communicated with the inlet of the second ejector 15 through a pipeline.

[0059] A spray assembly (including a spray pipe and a spray head) is arranged in the shell of the medium-pressure absorption cavity 183. A medium-pressure sub-rich liquid inlet and a medium-pressure rich liquid outlet are arranged on the shell of the medium-pressure absorption cavity 183. The medium-pressure sub-rich liquid inlet is communicated with the spray pipe and the first solution pump 12 through a pipeline. The medium-pressure rich liquid outlet is communicated with the second solution pump 4 through a pipeline. The left and right tube boxes of the medium-pressure absorption cavity 183 are respectively provided with a medium-pressure liquid refrigerant inlet and a medium-pressure gaseous refrigerant outlet. The medium-pressure liquid refrigerant inlet is communicated with the condenser 6 through a pipeline. The medium-pressure gaseous refrigerant outlet is communicated with the inlet of the second ejector 15 through a pipeline.

[0060] An opening is formed on the second partition plate 185 in the shell of the low-pressure absorption cavity 181. A liquid blocking plate is arranged in the opening. The inner cavity of the shell of the low-pressure absorption cavity 181 is communicated with the inner cavity of the shell of the low-pressure absorption cavity 182 through the opening. A through hole is formed on the second partition plate 185 in the shell of the medium-pressure absorption cavity 184. A liquid blocking plate is arranged in the through hole. The inner cavity of the shell of the medium-pressure absorption cavity 184 is communicated with the inner cavity of the shell of the medium-pressure absorption cavity 183 through the through hole.

[0061] In this embodiment, as a further optimized scheme, please refer to Figure 3 and Figure 4 The composite evaporative absorber 18 is installed above the composite generator 17 through a support plate.

[0062] A deep cooling step-by-step production process based on ejector condensation and enhanced heat absorption includes the following steps:

[0063] The heat source heats the high-pressure sub-rich liquid transported from the sub-high-pressure generation cavity 172 by the booster 7 in the shell side of the high-pressure generation cavity 171, so that most of the low-boiling-point refrigerant in the high-pressure sub-rich liquid is desorbed to become high-pressure gaseous refrigerant. The high-pressure gaseous refrigerant, as the heat source of the sub-high-pressure generation cavity 172, enters the tube side of the sub-high-pressure generation cavity 172 to heat the sub-high-pressure rich liquid transported from the medium-pressure absorption cavity 183 by the second solution pump 4 in the shell side, so that part of the low-boiling-point refrigerant in the sub-high-pressure rich liquid is desorbed to become sub-high-pressure gaseous refrigerant, which enters the first ejector 3 as an injection source;

[0064] The high-pressure gaseous refrigerant is condensed into high-pressure liquid refrigerant by the secondary high-pressure generating cavity 172, and then is decompressed into medium-pressure liquid refrigerant by the first expansion valve 5, and enters into the shell side of the medium-pressure evaporation cavity 184. A part of the medium-pressure liquid refrigerant is gasified into medium-pressure gaseous refrigerant by absorbing the heat of the heat carrier entering into the tube side of the medium-pressure evaporation cavity 184, and then enters into the shell side of the medium-pressure absorption cavity 183. The remaining medium-pressure liquid refrigerant is decompressed into low-pressure liquid refrigerant by the second expansion valve 13, and enters into the shell side of the low-pressure evaporation cavity 181. The heat carrier is cooled gradually, and thus the deep cooling process is completed.

[0065] The secondary high-pressure gaseous refrigerant enters into the first ejector 3, and then is decompressed into medium-pressure gaseous refrigerant by ejecting the secondary medium-pressure gaseous refrigerant from the second ejector 15. The medium-pressure gaseous refrigerant enters into the condenser 6, and is cooled into medium-pressure liquid refrigerant by circulating water. The medium-pressure liquid refrigerant is divided into two paths. One path enters into the tube side of the medium-pressure absorption cavity 183, and is used as the cold source of the medium-pressure absorption cavity 183. The other path is decompressed into low-pressure liquid refrigerant by the third expansion valve 14, and enters into the tube side of the low-pressure absorption cavity 182, and is used as the cold source of the low-pressure absorption cavity 182.

[0066] The remaining high-pressure lean liquid in the shell side of the high-pressure generating cavity 171 is decompressed into low-pressure lean liquid by the decompressor 16, and enters into the shell side of the low-pressure absorption cavity 182. The low-pressure gaseous refrigerant in the shell side of the low-pressure evaporation cavity 181 is mixed and absorbed by the low-pressure lean liquid, and becomes low-pressure lean-rich liquid. The heat released in the absorption process is absorbed by the low-pressure liquid refrigerant (cold source) in the tube side of the low-pressure absorption cavity 182, and the low-pressure liquid refrigerant is gasified into low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant is injected into the second ejector 15. The low-pressure lean-rich liquid is pressurized into medium-pressure lean-rich liquid by the first solution pump 12, and then enters into the shell side of the medium-pressure absorption cavity 183. The medium-pressure gaseous refrigerant in the shell side of the medium-pressure evaporation cavity 184 is mixed and absorbed by the medium-pressure lean-rich liquid, and becomes medium-pressure rich liquid. The heat released in the absorption process is absorbed by the medium-pressure liquid refrigerant (cold source) in the tube side of the medium-pressure absorption cavity 183, and the medium-pressure liquid refrigerant is gasified into medium-pressure gaseous refrigerant.

[0067] The medium-pressure gaseous refrigerant enters into the second ejector 15, and is used as the injection source to inject the low-pressure gaseous refrigerant from the low-pressure absorption cavity 182. The medium-pressure gaseous refrigerant is decompressed into secondary medium-pressure gaseous refrigerant by the secondary high-pressure gaseous refrigerant from the secondary high-pressure generating cavity 172, and then is injected into the first ejector 3 to become medium-pressure gaseous refrigerant. The medium-pressure gaseous refrigerant enters into the condenser 6, and is cooled into medium-pressure liquid refrigerant by circulating water. The medium-pressure liquid refrigerant continues the following cycle.

[0068] The medium pressure rich solution formed in the shell side of the medium pressure absorption cavity 183 is pressurized to a sub-high pressure rich solution by the second solution pump 4, and the sub-high pressure rich solution enters the shell side of the sub-high pressure generating cavity 171 to continue the following cycle.

[0069] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as limiting the scope of the patent of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the protection scope of the present application.

Claims

1. A deep cooling cascade production unit based on ejector condensation and enhanced heat absorption, characterized in that, Comprise: a generating assembly, an evaporation-absorption assembly, an ejector assembly and a condenser (6); the evaporation-absorption assembly comprises a medium-pressure evaporator (8), a low-pressure evaporator (9), a medium-pressure absorber (10) and a low-pressure absorber (11); the generating assembly uses a heat source to produce a cold source, the medium-pressure evaporator (8) uses part of the cold source produced by the generating assembly to preliminarily cool the carrier refrigerant, and the low-pressure evaporator (9) uses the remaining cold source discharged by the medium-pressure evaporator (8) to cool the carrier refrigerant again; the condenser (6) produces cold energy to be used as the cold source of the medium-pressure absorber (10) and the low-pressure absorber (11), and the ejector assembly uses the cold source after the medium-pressure absorber (10) to eject the cold source after the low-pressure absorber (11) and uses the gaseous refrigerant produced by the generating assembly to be injected into the condenser (6) to produce cold energy.

2. The deep cooling cascade production unit based on ejector condensation and enhanced heat absorption of claim 1, characterized in that, The generating assembly comprises a high-pressure generator (1) and a sub-high-pressure generator (2); the high-pressure generator (1) uses a heat source to heat the sub-rich liquid delivered by the sub-high-pressure generator (2) to make the sub-rich liquid form lean liquid and gaseous refrigerant, the sub-high-pressure generator (2) uses the gaseous refrigerant produced by the high-pressure generator (1) as a heat source to heat the rich liquid to make the rich liquid form sub-rich liquid and gaseous refrigerant, the gaseous refrigerant produced by the sub-high-pressure generator (2) is used as the injection source of the ejector assembly, and the gaseous refrigerant produced by the high-pressure generator (1) is used as the cold source of the medium-pressure evaporator (8) and the low-pressure evaporator (9) after being heated by the sub-high-pressure generator (2).

3. The deep cooling cascade production unit based on ejector condensation and enhanced heat absorption of claim 2, characterized in that, The generating assembly further comprises a booster (7) for boosting the sub-rich liquid inputted by the high-pressure generator (1) into the sub-high-pressure generator (2).

4. The deep cooling cascade generation unit based on ejector condensation and enhanced heat absorption of claim 2, characterized in that, The ejector assembly comprises a first ejector (3) and a second ejector (15), the second ejector (15) uses the cold source after the medium-pressure absorber (10) to eject the cold source after the low-pressure absorber (11), and the first ejector (3) uses the gaseous refrigerant produced by the sub-high-pressure generator (2) to eject the used cold source in the second ejector (15).

5. The deep cooling cascade production unit based on ejector condensation and enhanced heat absorption of claim 3, characterized in that, The evaporation-absorption assembly further comprises a first solution pump (12) and a second expansion valve (13); The deep cooling step-by-step production unit further comprises a second solution pump (4), a first expansion valve (5), a third expansion valve (14) and a pressure reducer (16), the second solution pump (4) is used to boost the rich liquid inputted by the medium-pressure absorber (10) into the sub-high-pressure generator (2), the first expansion valve (5) is used to reduce the pressure of the cold source inputted by the sub-high-pressure generator (2) into the medium-pressure evaporator (8), the third expansion valve (14) is used to reduce the pressure of the cold source inputted by the condenser (6) into the low-pressure absorber (11), and the pressure reducer (16) is used to reduce the pressure of the lean liquid inputted by the low-pressure absorber (11) into the high-pressure generator (1).

6. The deep cooling cascade production unit based on ejector condensation and enhanced heat absorption of claim 5, characterized in that, Both the booster (7) and the pressure reducer (16) are impeller turbine boosters, and the two impeller turbine boosters are linked through a transmission shaft (19).

7. The deep cooling cascade generation unit based on ejector condensation and enhanced heat absorption of claim 2, characterized in that, Use composite generator (17) instead of high pressure generator (1) and sub high pressure generator (2), use composite evaporation absorber (18) instead of medium pressure evaporator (8), low pressure evaporator (9), medium pressure absorber (10) and low pressure absorber (11), the composite generator (17) and composite evaporation absorber (18) are all fixed tube sheet heat exchanger, which is composed of head, tube box cylinder section, tube sheet, heat exchange tube and shell, the composite generator (17) is divided into high pressure generation cavity (171) and sub high pressure generation cavity (172), the composite evaporation absorber (18) is divided into low pressure evaporation cavity (181), low pressure absorption cavity (182), medium pressure absorption cavity (183) and medium pressure evaporation cavity (184).

8. The deep cooling cascade generation unit based on ejector condensation and enhanced heat absorption of claim 7, characterized in that, The high pressure generation cavity (171) and the sub high pressure generation cavity (172) are separated by the first partition (173), and the low pressure evaporation cavity (181), the low pressure absorption cavity (182), the medium pressure absorption cavity (183) and the medium pressure evaporation cavity (184) are separated by the second partition (185).

9. A deep cooling step-by-step production process based on ejector condensation and enhanced heat absorption, using a deep cooling step-by-step production unit based on ejector condensation and enhanced heat absorption according to claim 4, characterized in that: The steps include: The high pressure generator (1) heats the sub rich liquid delivered by the sub high pressure generator (2) using a heat source to produce gaseous refrigerant, the sub high pressure generator (2) uses the gaseous refrigerant produced by the high pressure generator (1) as a heat source to heat the rich liquid to form sub rich liquid and gaseous refrigerant, the gaseous refrigerant produced by the high pressure generator (1) is first introduced into the medium pressure evaporator (8) after being cooled by the sub high pressure generator (2) to preliminarily cool the carrier refrigerant, and the remaining cold source is introduced into the low pressure evaporator (9) to further cool the carrier refrigerant introduced by the medium pressure evaporator (8); The condenser (6) produces cold energy to be used as the cold source of the medium pressure absorber (10) and the low pressure absorber (11), the second ejector (15) uses the cold source after being used by the medium pressure absorber (10) to eject the cold source after being used by the low pressure absorber (11), and the first ejector (3) uses the gaseous refrigerant produced by the sub high pressure generator (2) to eject the cold source after being used by the second ejector (15) and introduce it into the condenser (6) to produce cold energy.

10. A deep cooling step-by-step production process based on ejector condensation and enhanced heat absorption, using a deep cooling step-by-step production unit based on ejector condensation and enhanced heat absorption according to any one of claims 7-8, characterized in that: The steps include: The high pressure generation cavity (171) heats the sub rich liquid delivered by the sub high pressure generation cavity (172) using a heat source to produce gaseous refrigerant, the sub high pressure generation cavity (172) uses the gaseous refrigerant produced by the high pressure generation cavity (171) as a heat source to heat the rich liquid to form sub rich liquid and gaseous refrigerant, the gaseous refrigerant produced by the high pressure generation cavity (171) is first introduced into the medium pressure evaporation cavity (184) after being cooled by the sub high pressure generation cavity (172) to preliminarily cool the carrier refrigerant, and the remaining cold source is introduced into the low pressure evaporation cavity (181) to further cool the carrier refrigerant introduced by the medium pressure evaporation cavity (184); The condenser (6) produces cold energy, which is used as the cold source of the medium-pressure absorption cavity (183) and the low-pressure absorption cavity (182) respectively. The second ejector (15) uses the cold energy after the medium-pressure absorption cavity (183) to eject the cold energy after the low-pressure absorption cavity (182). The first ejector (3) uses the gaseous refrigerant produced by the sub-high-pressure generation cavity (171) to eject the cold energy after the second ejector (15), and enters the condenser (6) to produce cold energy.

Images