An energy-efficient and high-performance refrigeration unit and process for preventing cavitation of steam condensate pumps.

Abstract

This invention discloses an energy-efficient refrigeration unit and process for preventing cavitation in a vapor condensate pump, comprising: a high-pressure generator, a medium-pressure generator, a high-pressure evaporator, a vapor condensate pump, a hybrid power generation compressor, and refrigeration components. This application utilizes a high-pressure evaporator to absorb the heat from the saturated vapor condensate flowing from the high-pressure generator using high-pressure liquid refrigerant, transforming the saturated vapor condensate into a subcooled vapor condensate. This prevents cavitation when the condensate enters the vapor condensate pump, replacing the previous method of increasing the height difference between the generator and the vapor condensate pump. This reduces the cost of the unit's piping and also reduces the cost of ultra-high-altitude transportation. Furthermore, the heat contained in the saturated vapor condensate is converted into the pressure energy of the high-pressure gaseous refrigerant, which drives the hybrid power generation compressor to operate, converting it into electrical energy and the pressure energy of the low-pressure gaseous refrigerant. The electrical energy powers the solution pump, achieving deep utilization of the unit's internal energy and improving the unit's COP.

Description

Technical Field

[0001] This invention relates to the field of refrigeration, and specifically to an energy-efficient refrigeration unit and process for preventing cavitation of steam condensate pumps. Background Technology

[0002] Absorption chillers utilize low-grade waste heat to drive a thermodynamic working fluid, and achieve refrigeration through the phase change of the working fluid (such as ammonia). The main equipment includes a generator, condenser, evaporator, absorber, solution pump, etc.

[0003] When the waste heat of the above-mentioned refrigeration units is in the form of steam, it is condensed into vapor liquid by the generator after heat absorption. The vapor liquid is mostly in a saturated state. The saturated vapor liquid is pressurized by the vapor liquid pump and sent to the owner's vapor liquid main. The saturated vapor liquid entering the vapor liquid pump can easily cause cavitation in the vapor liquid pump. The conventional approach is to increase the height difference between the generator and the vapor liquid pump to increase the effective net positive margin. However, this will increase the overall height of the unit, increase the cost of the unit's piping, and also increase the cost of ultra-high transportation. In addition, the circulating water, as the cold source of the absorber, directly affects the unit's refrigeration efficiency due to its temperature and heat absorption efficiency. Moreover, the heat absorbed is sensible heat temperature rise without phase change, so the heat absorption efficiency is limited. Furthermore, the circulating water temperature is affected by the wet-bulb temperature. In summer, due to the high wet-bulb temperature, the limit temperature of the cooling circulating water of the air-cooled tower is limited, resulting in a higher circulating water temperature. A higher circulating water temperature will cause the unit to be inefficient. Summary of the Invention

[0004] The purpose of this invention is to provide an energy-saving and efficient refrigeration unit and process for preventing cavitation of steam condensate pumps, which solves the problem of cavitation in existing refrigeration units.

[0005] The present invention achieves the above objectives through the following technical solution: an energy-saving and high-efficiency refrigeration unit for preventing cavitation of steam condensate pumps, comprising: a high-pressure generator, a medium-pressure generator, a high-pressure evaporator, a steam condensate pump, a composite power generator compressor, and refrigeration components;

[0006] The high-pressure generator uses the heat of steam to produce high-pressure gaseous refrigerant. The medium-pressure generator absorbs the heat of the high-pressure gaseous refrigerant produced by the high-pressure generator and liquefies it into high-pressure liquid refrigerant. The high-pressure evaporator uses the high-pressure liquid refrigerant discharged from the medium-pressure generator to absorb the heat of the steam after the high-pressure generator has been used and vaporizes it to drive the composite power compressor to generate electricity. The refrigeration component uses the heat absorbed by the medium-pressure generator to produce cooling capacity.

[0007] Preferably, the refrigeration assembly includes a second ejector, a condenser, an evaporator, a first ejector, an absorber, and a flash tank;

[0008] The condenser is used to supply liquid refrigerant to the evaporator and absorber respectively. The flash tank is used to flash the lean liquid discharged from the high-pressure generator to vaporize the refrigerant in the lean liquid. The first ejector uses the gaseous refrigerant discharged from the combined generator compressor as the ejector source to introduce the gaseous refrigerant in the evaporator into the absorber. The combined generator compressor is also used to pressurize the gaseous refrigerant discharged from the absorber and flash tank to serve as the ejector source for the second ejector, guiding the gaseous refrigerant discharged from the medium-pressure generator into the condenser.

[0009] Preferably, the refrigeration assembly further includes an expansion valve and a first solution pump. The expansion valve is used to reduce the pressure of the liquid refrigerant discharged from the condenser, and the first solution pump is used to pressurize the rich liquid in the absorber and input it into the medium-pressure generator.

[0010] Preferably, the energy-efficient refrigeration unit further includes a second solution pump, which is used to pressurize the rich solution from the medium-pressure generator and input it into the high-pressure generator.

[0011] Preferably, the composite power compressor includes an impeller turbine assembly, an impeller turbine power generation assembly, and an impeller turbine compression assembly connected to the output shaft of the impeller turbine assembly.

[0012] Preferably, Unit B is used to replace the high-pressure generator and the medium-pressure generator, and Unit A is used to replace the high-pressure evaporator, condenser, evaporator and absorber. Both Unit B and Unit A are fixed tube sheet heat exchangers whose main structure consists of end caps, tube box sections, tube sheets, heat exchange tubes and shell. The inner cavity of Unit B is divided into a medium-pressure generating cavity and a high-pressure generating cavity, and the inner cavity of Unit A is divided into a condensing cavity, a high-pressure evaporating cavity, an absorption cavity and an evaporating cavity.

[0013] Preferably, the medium-pressure generating chamber and the high-pressure generating chamber are separated by a first partition, and the condensing chamber, the high-pressure evaporating chamber, the absorption chamber and the evaporating chamber are separated by a second partition.

[0014] Preferably, unit A is located above unit B, and the inner cavities of the medium-pressure generating chamber, high-pressure generating chamber, high-pressure evaporating chamber, absorption chamber, and evaporating chamber are all equipped with spray components.

[0015] Preferably, an energy-efficient refrigeration process for preventing cavitation in steam condensate pumps, utilizing the aforementioned energy-efficient refrigeration unit for preventing cavitation in steam condensate pumps, includes the following steps:

[0016] Steam heats the high-pressure secondary rich liquid in the high-pressure generating chamber to produce high-pressure gaseous refrigerant. The high-pressure gaseous refrigerant enters the medium-pressure generating chamber as a heat source, absorbs heat and liquefies into high-pressure liquid refrigerant, which then enters the high-pressure evaporating chamber.

[0017] After the steam is heated and condensed into saturated steam condensate in the high-pressure generating chamber, it enters the high-pressure evaporating chamber to heat the high-pressure liquid refrigerant, causing it to vaporize into high-pressure gaseous refrigerant. The steam itself is cooled into subcooled steam condensate and enters the steam condensate pump.

[0018] High-pressure gaseous refrigerant enters the composite generator compressor to drive its generator, and the refrigeration components use the heat absorbed by the medium-pressure generating chamber to produce cooling capacity.

[0019] An energy-efficient refrigeration process for preventing cavitation in steam condensate pumps, utilizing the aforementioned energy-efficient refrigeration unit for preventing cavitation in steam condensate pumps, includes the following steps:

[0020] Steam heats the high-pressure secondary rich liquid in the high-pressure generator to produce high-pressure gaseous refrigerant. The high-pressure gaseous refrigerant enters the medium-pressure generator as a heat source, absorbs heat and liquefies into high-pressure liquid refrigerant, which then enters the high-pressure evaporator.

[0021] After the steam is heated and condensed into saturated steam condensate in the high-pressure generator, it enters the high-pressure evaporator to heat the high-pressure liquid refrigerant, causing it to vaporize into high-pressure gaseous refrigerant. The steam itself is cooled into subcooled steam condensate and enters the steam condensate pump.

[0022] High-pressure gaseous refrigerant enters the composite generator compressor to drive its generator, and the refrigeration components use the heat absorbed by the medium-pressure generator to produce cooling capacity.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. By using a high-pressure evaporator to absorb the heat of the saturated vapor condensate flowing from the high-pressure generator with high-pressure liquid refrigerant, the saturated vapor condensate is transformed into a subcooled vapor condensate. This prevents cavitation when the condensate enters the vapor condensate pump, replacing the original method of increasing the height difference between the generator and the vapor condensate pump. This reduces the cost of unit piping and ultra-high-voltage transportation. Furthermore, the heat contained in the saturated vapor condensate is converted into the pressure energy of the high-pressure gaseous refrigerant, which is used to drive the composite generator compressor to work, converting it into electrical energy and the pressure energy of the low-pressure gaseous refrigerant. The electrical energy powers the solution pump, enabling deep utilization of the unit's internal energy and improving the unit's COP.

[0025] 2. The sub-high pressure liquid refrigerant condensed in the condenser is depressurized to low pressure liquid refrigerant through the expansion valve, and one of the channels is used as the cold source for the absorber, replacing the circulating water. It absorbs heat in the absorber tubes, generates flow and boiling, and undergoes a phase change, which greatly improves its heat transfer efficiency, thereby improving the efficiency of the unit. Moreover, as a liquid refrigerant produced by the unit itself, its temperature is stable and it is minimally affected by the high temperature in summer.

[0026] 3. By replacing the original pressure reducing valve with a flash tank, the high-pressure lean liquid flowing from the high-pressure generator is flash-evaporated and depressurized, resulting in a lower concentration of refrigerant in the lean liquid before it enters the absorber, thus improving absorption efficiency. The low-pressure gaseous refrigerant flash-evaporated combines with the low-pressure gaseous refrigerant that has absorbed heat and vaporized in the absorber, and is then compressed into high-pressure gaseous refrigerant by a composite generator compressor. This high-pressure gaseous refrigerant is then ejected from the medium-pressure generator by a second ejector, and finally converted into a sub-high-pressure gaseous refrigerant that enters the condenser. This increases the condensing temperature of the condenser, reduces the condenser's requirement for low circulating water temperature, and thus improves condensing efficiency.

[0027] 4. The medium-pressure exhaust gas from the combined generator compressor is ejected by the first ejector to the low-pressure gaseous refrigerant that has absorbed heat and vaporized in the evaporator, and is converted into a secondary medium-pressure gaseous refrigerant that enters the absorber, thereby improving the absorption efficiency of the absorber and thus improving the cooling efficiency of the unit. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the energy-saving and high-efficiency refrigeration unit of the present invention;

[0029] Figure 2 This is a schematic diagram showing the connection between unit A and unit B of the present invention;

[0030] Figure 3 This is a schematic cross-sectional view of the connection between unit A and unit B of the present invention;

[0031] Figure 4 For the present invention Figure 3 Schematic diagram of EE direction;

[0032] Figure 5 This is a schematic diagram of the composite power generation compressor structure of the present invention.

[0033] In the diagram: 1. High-pressure generator; 2. Second solution pump; 3. Medium-pressure generator; 4. High-pressure evaporator; 5. Steam condensate pump; 6. Combined power generation compressor; 601. Impeller turbine assembly; 602. Impeller turbine power generation assembly; 603. Impeller turbine compression assembly; 7. Second ejector; 8. Condenser; 9. Expansion valve; 10. Evaporator; 11. First ejector; 12. Absorber; 13. First solution pump; 14. Flash tank; 15. Unit B; 151. Medium-pressure generating chamber; 152. High-pressure generating chamber; 153. First baffle; 16. Unit A; 161. Condensation chamber; 162. High-pressure evaporation chamber; 163. Absorption chamber; 164. Evaporation chamber; 165. Second baffle. Detailed Implementation

[0034] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0035] Example 1

[0036] Please see Figure 1 An energy-saving and high-efficiency refrigeration unit with anti-cavitation properties for steam condensate pumps includes: a high-pressure generator 1, a second solution pump 2, a medium-pressure generator 3, a high-pressure evaporator 4, a steam condensate pump 5, a composite generator compressor 6, and refrigeration components.

[0037] The refrigeration components include a second ejector 7, a condenser 8, an expansion valve 9, an evaporator 10, a first ejector 11, an absorber 12, a first solution pump 13, and a flash tank 14.

[0038] The rich liquid inlet of high-pressure generator 1 is connected to the rich liquid outlet of medium-pressure generator 3 via the second solution pump 2. The high-pressure gaseous refrigerant outlet of high-pressure generator 1 is connected to the heat source inlet of medium-pressure generator 3. The heat source outlet of high-pressure generator 1 is connected to high-pressure evaporator 4. The high-pressure lean liquid outlet of high-pressure generator 1 is connected to flash tank 14. The heat source outlet of medium-pressure generator 3 is connected to high-pressure evaporator 4. The rich liquid inlet of medium-pressure generator 3 is connected to the rich liquid outlet of absorber 12 via the first solution pump 13. The medium-pressure gaseous refrigerant outlet of medium-pressure generator 3 is connected to the second ejector 7. The vapor condensate outlet of high-pressure evaporator 4 is connected to vapor condensate pump 5. The high-pressure gaseous refrigerant outlet of high-pressure evaporator 4 is connected to combined power generation compressor 6. The medium-pressure exhaust gas outlet of combined power generation compressor 6 is connected to the first ejector 11. The gaseous refrigerant inlet of the composite power compressor 6 is connected to the gaseous refrigerant outlet of the flash tank 14 and the cooling medium outlet (gaseous refrigerant outlet) of the absorber 12. The gaseous refrigerant outlet of the composite power compressor 6 is connected to the second ejector 7. The outlet of the second ejector 7 is connected to the gaseous refrigerant inlet of the condenser 8. The liquid refrigerant outlet of the condenser 8 is connected to the expansion valve 9. The expansion valve 9 has two outlets: one outlet is connected to the liquid refrigerant inlet of the evaporator 10, and the other outlet is connected to the cooling medium inlet (liquid refrigerant inlet) of the absorber 12. The gaseous refrigerant outlet of the evaporator 10 is connected to the first ejector 11. The outlet of the first ejector 11 is connected to the gaseous refrigerant inlet of the absorber 12. The lean liquid outlet of the flash tank 14 is connected to the lean liquid inlet of the absorber 12.

[0039] Please see Figure 5The composite power generation compressor 6 includes an impeller turbine assembly 601 and an impeller turbine power generation assembly 602 and an impeller turbine compression assembly 603 (composed of a housing and an impeller inside the housing) connected to the output shaft of the impeller turbine assembly 601. The inlet of the impeller turbine assembly 601 is connected to the high-pressure gaseous refrigerant outlet of the high-pressure evaporator 4, and the outlet of the impeller turbine assembly 601 is connected to the first ejector 11. The inlet of the impeller turbine compression assembly 603 is connected to the gaseous refrigerant outlet of the flash tank 14 and the cooling medium outlet of the absorber 12, and the outlet of the impeller turbine compression assembly 603 is connected to the second ejector 7. The high-pressure gaseous refrigerant discharged from the high-pressure evaporator 4 enters the impeller turbine assembly 601, driving it to rotate, thereby causing the impeller turbine power generation assembly 602 to rotate and generate electricity, and the impeller turbine compression assembly 603 to rotate and compress the gas.

[0040] An energy-efficient refrigeration process for preventing cavitation in steam condensate pumps includes the following steps:

[0041] Steam heats the high-pressure secondary rich liquid delivered from the medium-pressure generator 3 by the second solution pump 2 in the high-pressure generator 1, causing most of the low-boiling-point refrigerant in the high-pressure secondary rich liquid to desorb and become high-pressure gaseous refrigerant. The high-pressure gaseous refrigerant enters the medium-pressure generator 3 as a heat source to heat the medium-pressure rich liquid delivered from the absorber 12 by the first solution pump 13, causing some of the low-boiling-point refrigerant in the medium-pressure rich liquid to desorb and become medium-pressure gaseous refrigerant. The medium-pressure gaseous refrigerant is then ejected into the second ejector 7.

[0042] Steam is absorbed and condensed into saturated steam condensate in high-pressure generator 1. The saturated steam condensate enters high-pressure evaporator 4. High-pressure gaseous refrigerant in medium-pressure generator 3 is absorbed and condensed into high-pressure liquid refrigerant, which then enters high-pressure evaporator 4. It absorbs heat from the saturated steam condensate and vaporizes into high-pressure gaseous refrigerant. The high-pressure gaseous refrigerant enters compound generator compressor 6, which drives it to work and becomes medium-pressure exhaust gas. The medium-pressure exhaust gas serves as an ejector source and enters the first ejector 11. The saturated steam condensate is absorbed and cooled into subcooled steam condensate in high-pressure evaporator 4, and then enters steam condensate pump 5 to be pressurized and sent to the owner's steam condensate main pipe.

[0043] The high-pressure lean liquid remaining after the generation process in the high-pressure generator 1 enters the flash tank 14, where low-pressure gaseous refrigerant is flashed out and then becomes low-pressure lean liquid, which enters the absorber 12. The low-pressure gaseous refrigerant flowing out of the flash tank 14 enters the combined generator compressor 6 and is compressed into high-pressure gaseous refrigerant. The high-pressure gaseous refrigerant acts as an ejector source and enters the second ejector 7 to eject the medium-pressure gaseous refrigerant flowing out of the medium-pressure generator 3. It then becomes sub-high-pressure gaseous refrigerant and enters the condenser 8 where it is condensed into sub-high-pressure liquid refrigerant by circulating water.

[0044] The high-pressure liquid refrigerant is reduced to low-pressure liquid refrigerant by expansion valve 9. The low-pressure liquid refrigerant is divided into two streams: one stream acts as the cold source in absorber 12 during the absorption process, entering absorber 12; the other stream enters evaporator 10, absorbing heat from the refrigerant and becoming low-pressure gaseous refrigerant. This gaseous refrigerant is then ejected from the medium-pressure exhaust gas flowing from the combined generator compressor 6 into the first ejector 11, becoming secondary medium-pressure gaseous refrigerant. This secondary medium-pressure gaseous refrigerant then enters absorber 1... In step 2, the low-pressure lean liquid flowing out of flash tank 14 is mixed and absorbed to become low-pressure rich liquid. The heat released during the absorption process is absorbed by the cold source (low-pressure liquid refrigerant) entering the absorber 12. The cold source (low-pressure liquid refrigerant) absorbs heat and vaporizes into low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant merges with the low-pressure gaseous refrigerant flashed out of flash tank 14 and enters the composite power compressor 6 to be compressed into high-pressure gaseous refrigerant, which enters the second ejector 7 as an ejector source to continue the subsequent cycle.

[0045] The low-pressure rich solution formed in absorber 12 is pressurized into medium-pressure rich solution by first solution pump 13, and the medium-pressure rich solution enters medium-pressure generator 3 to continue the subsequent cycle.

[0046] It should be noted that the high-pressure gaseous refrigerant flowing out of the high-pressure evaporator 4 enters the composite power compressor 6. After driving it to work, it generates electricity to power the first solution pump 13 and the second solution pump 2, and compresses the low-pressure gaseous refrigerant into high-pressure gaseous refrigerant.

[0047] Example 2

[0048] As a further optimization of Example 1, please refer to Figure 2 , Figure 3 and Figure 4 Unit B15 is used to replace high-pressure generator 1 and medium-pressure generator 3, and unit A16 is used to replace high-pressure evaporator 4, condenser 8, evaporator 10 and absorber 12. Both units B15 and A16 are fixed tube sheet heat exchangers whose main structure consists of end caps, tube box sections, tube sheets, heat exchange tubes and shell. Unit B15 is provided with a first partition 153, which is used to divide the inner cavity of unit B15 into a medium-pressure generating chamber 151 and a high-pressure generating chamber 152. Unit A16 is provided with a second partition 165, which is used to divide the inner cavity of unit A16 into a condensing chamber 161, a high-pressure evaporating chamber 162, an absorption chamber 163 and an evaporating chamber 164. Both the first partition 153 and the second partition 165 are coated with an insulation layer.

[0049] The condenser 161 has a sub-high pressure gaseous refrigerant inlet and a sub-high pressure liquid refrigerant outlet on its shell. The sub-high pressure gaseous refrigerant inlet is connected to the outlet of the second ejector 7 through a pipe, and the sub-high pressure liquid refrigerant outlet is connected to the expansion valve 9 through a pipe. The left and right pipe boxes of the condenser 161 are respectively equipped with circulating water inlet and outlet.

[0050] The shell of the high-pressure evaporation chamber 162 is equipped with a spray assembly (including spray pipes and nozzles). The shell of the high-pressure evaporation chamber 162 is equipped with a high-pressure liquid refrigerant inlet and a high-pressure gaseous refrigerant outlet. The high-pressure liquid refrigerant inlet is connected to the spray pipe and the tube side of the medium-pressure generating chamber 151 through a pipe. The high-pressure gaseous refrigerant outlet is connected to the composite generator compressor 6 through a pipe. The left and right tube boxes of the high-pressure evaporation chamber 162 are respectively equipped with a saturated steam condensate inlet and a subcooled steam condensate outlet. The subcooled steam condensate outlet is connected to the steam condensate pump 5 through a pipe.

[0051] The absorption chamber 163 is equipped with a spray assembly (including a spray pipe and a nozzle) inside its shell. The absorption chamber 163 is equipped with a low-pressure lean liquid inlet, a secondary medium-pressure gaseous refrigerant inlet, and a low-pressure rich liquid outlet. The low-pressure lean liquid inlet is connected to the spray pipe and the flash tank 14 through a pipe. The secondary medium-pressure gaseous refrigerant inlet is connected to the outlet of the first ejector 11 through a pipe. The low-pressure rich liquid outlet is connected to the inlet of the first solution pump 13 through a pipe. The left and right pipe boxes of the absorption chamber 163 are respectively equipped with a low-pressure liquid refrigerant inlet and a low-pressure gaseous refrigerant outlet. The low-pressure liquid refrigerant inlet is connected to the expansion valve 9 through a pipe. The low-pressure gaseous refrigerant outlet is connected to the composite generator compressor 6 through a pipe.

[0052] The evaporator chamber 164 is equipped with a spray assembly (including a spray pipe and a nozzle) inside its shell. The evaporator chamber 164 is equipped with a low-pressure liquid refrigerant inlet and a low-pressure gaseous refrigerant outlet. The low-pressure liquid refrigerant inlet is connected to the spray pipe and expansion valve 9 through a pipe, and the low-pressure gaseous refrigerant outlet is connected to the first ejector 11 through a pipe. The left and right pipe boxes of the evaporator chamber 164 are respectively equipped with a refrigerant inlet and outlet.

[0053] The shell of the medium-pressure generating chamber 151 is equipped with a spray assembly (including a spray pipe and a nozzle). The shell of the medium-pressure generating chamber 151 is equipped with a medium-pressure rich liquid inlet, a medium-pressure gaseous refrigerant outlet and a medium-pressure secondary rich liquid outlet. The medium-pressure rich liquid inlet is connected to the spray pipe and the outlet of the first solution pump 13 through a pipe. The medium-pressure gaseous refrigerant outlet is connected to the inlet of the second ejector 7 through a pipe. The medium-pressure secondary rich liquid outlet is connected to the inlet of the second solution pump 2 through a pipe. The left and right pipe boxes of the medium-pressure generating chamber 151 are respectively equipped with a high-pressure gaseous refrigerant inlet and a high-pressure liquid refrigerant outlet. The high-pressure liquid refrigerant outlet is connected to the shell side of the high-pressure evaporating chamber 162 through a pipe.

[0054] The high-pressure generating chamber 152 is equipped with a spray assembly (including a spray pipe and a nozzle) inside its shell. The high-pressure generating chamber 152 is equipped with a high-pressure sub-rich liquid inlet, a high-pressure gaseous refrigerant outlet, and a high-pressure lean liquid outlet. The high-pressure sub-rich liquid inlet is connected to the spray pipe and the outlet of the second solution pump 2 through a pipe. The high-pressure gaseous refrigerant outlet is connected to the high-pressure gaseous refrigerant inlet on the left tube box of the medium-pressure generating chamber 151 through a pipe. The high-pressure lean liquid outlet is connected to the flash tank 14 through a pipe. The left and right tube boxes of the high-pressure generating chamber 152 are respectively equipped with a saturated vapor condensate outlet and a steam inlet. The saturated vapor condensate outlet is connected to the saturated vapor condensate inlet on the left tube box of the high-pressure evaporating chamber 162 through a pipe.

[0055] In this embodiment, as a further optimization, please refer to... Figure 3 and Figure 4 Unit A16 is located above unit B15; the medium-pressure generating chamber 151 is located above the high-pressure generating chamber 152; the condensing chamber 161, the high-pressure evaporating chamber 162, the absorption chamber 163 and the evaporating chamber 164 are located in the first, second, third and fourth quadrants, respectively.

[0056] An energy-efficient refrigeration process for preventing cavitation in steam condensate pumps includes the following steps:

[0057] Steam heats the high-pressure secondary rich liquid delivered from the shell side of the medium-pressure generating chamber 151 by the second solution pump 2 in the shell side of the high-pressure generating chamber 152, causing most of the low-boiling-point refrigerant in the high-pressure secondary rich liquid to desorb and become high-pressure gaseous refrigerant. The high-pressure gaseous refrigerant enters the tube side of the medium-pressure generating chamber 151 as a heat source to heat the medium-pressure rich liquid delivered from the shell side of the absorption chamber 163 by the first solution pump 13, causing some of the low-boiling-point refrigerant in the medium-pressure rich liquid to desorb and become medium-pressure gaseous refrigerant, which is then ejected into the second ejector 7.

[0058] After absorbing heat and condensing into saturated vapor condensate in the tube side of the high-pressure generating chamber 152, the steam enters the tube side of the high-pressure evaporating chamber 162. The high-pressure gaseous refrigerant entering the tube side of the medium-pressure generating chamber 151 is absorbed heat and condensed into high-pressure liquid refrigerant, which then enters the shell side of the high-pressure evaporating chamber 162. It absorbs heat from the saturated vapor condensate entering the tube side and vaporizes into high-pressure gaseous refrigerant. The high-pressure gaseous refrigerant enters the impeller turbine assembly of the composite generator compressor 6, drives it to work, and becomes medium-pressure exhaust gas. The medium-pressure exhaust gas serves as an ejector source and enters the first ejector 11. The saturated vapor condensate is absorbed heat and cooled into subcooled vapor condensate in the tube side of the high-pressure evaporating chamber 162, and then enters the vapor condensate pump 5 to be pressurized and sent to the owner's vapor condensate main pipe.

[0059] The high-pressure lean liquid remaining in the shell side of the high-pressure generating chamber 152 after the generation process enters the flash tank 14, where low-pressure gaseous refrigerant is flashed out. After becoming low-pressure lean liquid, it enters the shell side of the absorption chamber 163. The low-pressure gaseous refrigerant flowing out of the flash tank 14 enters the impeller turbine compression assembly of the composite generator compressor 6 and is compressed into high-pressure gaseous refrigerant. The high-pressure gaseous refrigerant acts as an ejector source and enters the second ejector 7 to eject the medium-pressure gaseous refrigerant flowing out of the shell side of the medium-pressure generating chamber 151. It then becomes a sub-high-pressure gaseous refrigerant and enters the shell side of the condensing chamber 161 where it is condensed into a sub-high-pressure liquid refrigerant by circulating water.

[0060] The high-pressure liquid refrigerant is reduced to low-pressure liquid refrigerant by expansion valve 9. The low-pressure liquid refrigerant is divided into two streams: one stream acts as the cold source during the absorption process in absorption chamber 163, entering the tube side of absorption chamber 163; the other stream enters the shell side of evaporator chamber 164, absorbing heat from the refrigerant and becoming low-pressure gaseous refrigerant. This gaseous refrigerant is then ejected by the medium-pressure exhaust gas flowing from the composite generator compressor 6 into the first ejector 11, becoming secondary medium-pressure gaseous refrigerant. This secondary medium-pressure gaseous refrigerant then enters absorption chamber 163. In the shell side, it mixes and absorbs with the low-pressure lean liquid flowing out of flash tank 14, becoming low-pressure rich liquid; the heat released during the absorption process is absorbed by the cold source (low-pressure liquid refrigerant) in the tube side of the absorption chamber 163, and the cold source (low-pressure liquid refrigerant) absorbs heat and vaporizes into low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant merges with the low-pressure gaseous refrigerant flashed out of flash tank 14 and enters the impeller turbine compression assembly of the composite power compressor 6, where it is compressed into high-pressure gaseous refrigerant, which enters the second ejector 7 as an ejector source to continue the subsequent cycle;

[0061] The low-pressure rich solution formed in the shell side of the absorption chamber 163 is pressurized into a medium-pressure rich solution by the first solution pump 13. The medium-pressure rich solution enters the shell side of the medium-pressure generating chamber 151 and continues the subsequent cycle.

[0062] It should be noted that integrating the high-pressure evaporator 4, condenser 8, evaporator 10, and absorber 12 into one unit, namely unit A16, and integrating the high-pressure generator 1 and medium-pressure generator 3 into one unit, namely unit B15, can reduce the cost of equipment and piping, greatly reduce the unit's footprint, and facilitate skid-mounted installation of the unit.

[0063] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. An energy-efficient refrigeration unit with anti-cavitation properties for steam condensate pumps, characterized in that, include: High-pressure generator (1), medium-pressure generator (3), high-pressure evaporator (4), steam condensate pump (5), combined power generation compressor (6), and refrigeration components; The high-pressure generator (1) uses the heat of steam to produce high-pressure gaseous refrigerant. The medium-pressure generator (3) is used to absorb the heat of the high-pressure gaseous refrigerant produced by the high-pressure generator (1) and liquefy it into high-pressure liquid refrigerant. The high-pressure evaporator (4) uses the high-pressure liquid refrigerant discharged from the medium-pressure generator (3) to absorb the heat of the steam after the high-pressure generator (1) is used and vaporize it to drive the composite power compressor (6) to generate electricity. The refrigeration component is used to produce cooling capacity using the heat absorbed by the medium-pressure generator (3). The refrigeration assembly includes a second ejector (7), a condenser (8), an evaporator (10), a first ejector (11), an absorber (12), and a flash tank (14). The condenser (8) is used to supply liquid refrigerant to the evaporator (10) and the absorber (12) respectively. The flash tank (14) is used to flash the lean liquid discharged from the high-pressure generator (1) so that the refrigerant in the lean liquid is vaporized. The first ejector (11) uses the gaseous refrigerant discharged from the composite power compressor (6) as the ejector source to introduce the gaseous refrigerant in the evaporator (10) into the absorber (12). The composite power compressor (6) is also used to pressurize the gaseous refrigerant discharged from the absorber (12) and the flash tank (14) as the ejector source of the second ejector (7) to guide the gaseous refrigerant discharged from the medium-pressure generator (3) into the condenser (8). The steam condensate outlet of the high-pressure evaporator (4) is connected to the steam condensate pump (5).

2. The energy-saving and high-efficiency refrigeration unit for preventing steam condensate pump cavitation according to claim 1, characterized in that, The refrigeration assembly also includes an expansion valve (9) and a first solution pump (13). The expansion valve (9) is used to reduce the pressure of the liquid refrigerant discharged from the condenser (8), and the first solution pump (13) is used to pressurize the rich liquid in the absorber (12) and input it into the medium-pressure generator (3).

3. The energy-saving and high-efficiency refrigeration unit for preventing steam condensate pump cavitation according to claim 1, characterized in that, The energy-efficient refrigeration unit also includes a second solution pump (2), which is used to pressurize the rich liquid from the medium-pressure generator (3) and input it into the high-pressure generator (1).

4. The energy-saving and high-efficiency refrigeration unit for preventing steam condensate pump cavitation according to claim 1, characterized in that, The composite power compressor (6) includes an impeller turbine assembly (601) and an impeller turbine power generation assembly (602) and an impeller turbine compression assembly (603) connected to the output shaft of the impeller turbine assembly (601).

5. The energy-saving and high-efficiency refrigeration unit for preventing steam condensate pump cavitation according to claim 1, characterized in that, Unit B (15) is used to replace the high-pressure generator (1) and the medium-pressure generator (3), and Unit A (16) is used to replace the high-pressure evaporator (4), condenser (8), evaporator (10) and absorber (12). Both Unit B (15) and Unit A (16) are fixed tube sheet heat exchangers whose main structure consists of end caps, tube box sections, tube sheets, heat exchange tubes and shells. The inner cavity of Unit B (15) is divided into a medium-pressure generating chamber (151) and a high-pressure generating chamber (152). The inner cavity of Unit A (16) is divided into a condensing chamber (161), a high-pressure evaporating chamber (162), an absorption chamber (163) and an evaporating chamber (164).

6. The energy-saving and high-efficiency refrigeration unit for preventing steam condensate pump cavitation according to claim 5, characterized in that, The medium-pressure generating chamber (151) and the high-pressure generating chamber (152) are separated by a first partition (153), and the condensing chamber (161), the high-pressure evaporating chamber (162), the absorption chamber (163) and the evaporating chamber (164) are separated by a second partition (165).

7. The energy-saving and high-efficiency refrigeration unit for preventing steam condensate pump cavitation according to claim 5, characterized in that, The unit A (16) is located above the unit B (15), and the inner cavities of the medium pressure generating chamber (151), high pressure generating chamber (152), high pressure evaporation chamber (162), absorption chamber (163) and evaporation chamber (164) are all equipped with spray components.

8. An energy-efficient refrigeration process for preventing cavitation in steam condensate pumps, utilizing an energy-efficient refrigeration unit for preventing cavitation in steam condensate pumps as described in any one of claims 1-4, characterized in that... Includes the following steps: Steam heats the high-pressure secondary rich liquid in the high-pressure generator (1) to produce high-pressure gaseous refrigerant. The high-pressure gaseous refrigerant enters the medium-pressure generator (3) as a heat source, absorbs heat and liquefies into high-pressure liquid refrigerant, which then enters the high-pressure evaporator (4). After the steam is heated and condensed into saturated steam condensate in the high-pressure generator (1), it enters the high-pressure evaporator (4) to heat the high-pressure liquid refrigerant and vaporize it into high-pressure gaseous refrigerant. The steam itself is cooled into subcooled steam condensate and enters the steam condensate pump (5). High-pressure gaseous refrigerant enters the composite generator compressor (6) to drive its generator, and the refrigeration component uses the heat absorbed by the medium-pressure generator (3) to generate cooling capacity.

9. An energy-efficient refrigeration process for preventing cavitation in steam condensate pumps, utilizing an energy-efficient refrigeration unit for preventing cavitation in steam condensate pumps as described in any one of claims 5-7, characterized in that... Includes the following steps: Steam heats the high-pressure secondary rich liquid in the high-pressure generating chamber (152) to produce high-pressure gaseous refrigerant. The high-pressure gaseous refrigerant enters the medium-pressure generating chamber (151) as a heat source, absorbs heat and liquefies into high-pressure liquid refrigerant, which then enters the high-pressure evaporating chamber (162). After the steam is heated and condensed into saturated steam condensate in the high-pressure generating chamber (152), it enters the high-pressure evaporating chamber (162) to heat the high-pressure liquid refrigerant and vaporize it into high-pressure gaseous refrigerant. The steam itself is cooled into subcooled steam condensate and enters the steam condensate pump (5). High-pressure gaseous refrigerant enters the composite generator compressor (6) to drive its generator, and the refrigeration component uses the heat absorbed by the medium-pressure generating chamber (151) to generate cooling capacity.

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