CN109341120B

CN109341120B - Flooded refrigerating system

Info

Publication number: CN109341120B
Application number: CN201811356740.3A
Authority: CN
Inventors: 王恒; 张进; 施磊; 施贤彪; 汪洪文
Original assignee: Suzhou Limat Energy Equipment Co ltd
Current assignee: Suzhou Limat Energy Equipment Co ltd
Priority date: 2018-11-15
Filing date: 2018-11-15
Publication date: 2024-03-01
Anticipated expiration: 2038-11-15
Also published as: CN109341120A

Abstract

The invention discloses a flooded refrigeration system, which comprises a compressor, a condenser, an expansion valve and an evaporator which are sequentially communicated through a first pipeline, wherein the evaporator is a flooded evaporator, and comprises a first shell for storing refrigerant, a plurality of first oil return ports arranged on the first shell, and a plurality of heat exchange pipes arranged in the first shell, wherein at least one heat exchange pipe is exposed above the liquid level of the refrigerant. According to the flooded refrigeration system, at least one heat exchange tube is exposed above the liquid level of the refrigerant, so that the refrigerant can be completely located in the heat exchange area, and the damage to a compressor caused by sampling a large amount of freon liquid at an oil return port is avoided; the arrangement of the plurality of oil return ports avoids the condition of oil return operation cutoff under the condition of equipment swinging.

Description

Flooded refrigerating system

Technical Field

The invention relates to a refrigerating system, in particular to a flooded refrigerating system.

Background

The refrigerating system consists of refrigerant and four parts, i.e. compressor, condenser, expansion valve and evaporator. The evaporator generally includes a dry evaporator and a flooded evaporator.

In the marine industry, the evaporator is generally a dry evaporator, and the lubricating oil entrained in the heat exchange tube is flushed back to the compressor through evaporation of the refrigerant in the heat exchange tube and the flow rate of the gasified expansion volume increase. However, the refrigerating capacity of the dry evaporator directly corresponds to the circulating capacity of the system refrigerant, and when the refrigerating capacity is relatively large, the circulating capacity of the refrigerant is correspondingly increased; meanwhile, in a large system, the system can adjust working conditions to generate higher superheat degree, so that the application of the dry evaporator in a refrigerating system with larger cold capacity is limited.

For the flooded evaporator, an oil return port of the flooded evaporator is usually arranged at a fixed position of an oil-rich layer of the evaporator, and in the running process of a ship, the swing of the ship can enable oil return operation to stop or the oil return port to sample a large amount of freon liquid, and the freon liquid enters a compressor through an injection valve to damage mechanical equipment. Therefore, under the condition that the equipment swings, oil return operation is difficult to be carried out through the fixed oil return port, and the service life of the compressor is influenced.

Disclosure of Invention

The invention aims to provide a flooded refrigeration system, which adopts a flooded evaporator, and can normally return oil under the condition that equipment swings; meanwhile, in the circulation process of the refrigerant, the refrigerant entering the air suction port of the compressor can be ensured to be in a gaseous state, so that the phenomenon of liquid impact is avoided, and the operation safety of the compressor is ensured.

In order to achieve the above purpose, the invention adopts the following technical scheme:

the utility model provides a flooded refrigerating system, includes compressor, condenser, expansion valve and the evaporimeter that communicates in proper order through first pipeline, the evaporimeter is flooded evaporimeter, and it includes the first casing that is used for depositing the refrigerant, set up in a plurality of first oil return openings on the first casing, locate a plurality of heat exchange tubes that are used for letting in and out the heat source in the first casing, wherein at least one heat exchange tube expose to the liquid level top of refrigerant, flooded refrigerating system still includes the regenerator, the regenerator through the second pipeline with first oil return opening with the compressor is linked together.

Preferably, the first oil return ports include three first upper oil return ports arranged on the first shell and flush with the refrigerant liquid level, first lower oil return ports arranged on the bottom of the first shell, and first middle oil return ports arranged between the first upper oil return ports and the first lower oil return ports.

Preferably, the flooded refrigeration system further comprises a first oil return pipe communicated with the first oil return port and a first regulating valve arranged on the first oil return pipe, and the first oil return pipe is communicated with the second pipeline.

Preferably, the flooded refrigeration system further comprises a liquid collecting pipe communicated with the flooded evaporator, a second oil return port arranged at the bottom of the liquid collecting pipe, a second oil return pipe communicated with the second oil return port, and a second regulating valve arranged on the second oil return pipe, wherein the second oil return pipe is communicated with the second pipeline.

Still preferably, the flooded refrigeration system further comprises a third pipeline communicated between the liquid collecting pipe and the flooded evaporator, and a first stop valve arranged on the third pipeline, and a liquid level switch and a liquid level transmitter are arranged on the liquid collecting pipe.

Preferably, the condenser comprises a second shell and a condensing tube arranged in the second shell, two ends of the condensing tube are respectively communicated with a cold source inlet and a cold source outlet, the heat regenerator and the condenser are arranged in the same shell, the heat regenerator comprises a heat regenerating tube penetrating through the second shell, and the heat regenerating tube is communicated with the second pipeline.

Preferably, the flooded refrigeration system further comprises a second stop valve, a first filter and a first electromagnetic valve which are sequentially arranged on the first pipeline along the direction away from the condenser and close to the flooded evaporator, and the expansion valve is arranged between the first electromagnetic valve and the flooded evaporator.

Preferably, the flooded refrigeration system further comprises a third stop valve, a second filter, a second electromagnetic valve and a first liquid viewing mirror which are sequentially arranged on the second pipeline along the direction away from the flooded evaporator and close to the regenerator.

Preferably, the flooded refrigeration system further comprises a second liquid viewing mirror, a third regulating valve and a fourth stop valve which are sequentially arranged on the second pipeline along the direction away from the heat regenerator and close to the compressor.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages: according to the flooded refrigeration system, at least one heat exchange tube is exposed above the liquid level of the refrigerant, so that the refrigerant can be fully positioned in the heat exchange area, the refrigerant and the oil are mixed together due to continuous boiling, and the damage to a compressor caused by sampling a large amount of freon liquid at an oil return port is avoided; meanwhile, the arrangement of the plurality of oil return ports avoids the condition of oil return operation cutoff under the condition of equipment swinging; and at least one heat exchange tube exposed above the liquid level of the refrigerant can be used as a superheating section to superheat the evaporated refrigerant steam, so that the refrigerant sucked into the air suction port of the compressor is ensured to be in a gaseous state, the phenomenon of liquid impact is avoided, and the operation safety of the compressor is ensured.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Wherein: 1. a first pipeline; 2. a compressor; 3. a condenser; 31. a second housing; 32. a cold source inlet; 33. a cold source outlet; 4. an expansion valve; 5. a flooded evaporator; 51. a first housing; 52. a first oil return port; 521. a first upper oil return port; 522. a first lower oil return port; 523. a first middle oil return port; 53. a first oil return pipe; 54. a first regulating valve; 6. a regenerator; 61. a heat return pipe; 7. a second pipeline; 8. a liquid collecting pipe; 81. a second oil return port; 82. a second oil return pipe; 83. a second regulating valve; 9. a third pipeline; 10. a first stop valve; 11. a liquid level switch; 12. a liquid level transmitter; 13. a second shut-off valve; 14. A first filter; 15. a first electromagnetic valve; 16. a third stop valve; 17. a second filter; 18. a second electromagnetic valve; 19. a first liquid viewing mirror; 20. a second liquid viewing mirror; 21. a third regulating valve; 22. a fourth shut-off valve; 23. a heat source inlet; 24. and a heat source outlet.

Detailed Description

The technical scheme of the invention is further described below with reference to the accompanying drawings.

Referring to fig. 1, a flooded refrigeration system includes a compressor 2, a condenser 3, an expansion valve 4 and an evaporator which are sequentially communicated through a first pipeline 1, wherein the evaporator is a flooded evaporator 5, and includes a first shell 51 for storing a refrigerant, a plurality of first oil return ports 52 formed on the first shell 51, and a plurality of heat exchange pipes (not shown in the figure) arranged in the first shell 51 and used for introducing a heat source and discharging the heat source, at least one of the heat exchange pipes is exposed above the liquid level of the refrigerant, and the flooded refrigeration system further includes a regenerator 6, and the regenerator 6 is communicated with the first oil return ports 52 and the compressor 2 through a second pipeline 7. Here, the compressor 2 is a screw compressor, and is driven by a motor. The expansion valve 4 is an electronic expansion valve. The heat exchange tube communicates with the heat source inlet 23 and the heat source outlet 24.

Here, by exposing at least one heat exchange tube above the liquid level of the refrigerant so that the refrigerant can be located entirely within the heat exchange zone, the refrigerant and oil are mixed together by continuous boiling, avoiding the first oil return port 52 sampling a large amount of freon liquid to damage the compressor 2; meanwhile, the arrangement of the plurality of first oil return ports 52 avoids the condition of oil return operation cutoff under the condition of equipment swinging; and at least one heat exchange tube exposed above the liquid level of the refrigerant can be used as a superheating section to superheat the evaporated refrigerant steam, so that the refrigerant sucked into the air suction port of the compressor 2 is ensured to be in a gaseous state, the phenomenon of liquid impact is avoided, and the operation safety of the compressor 2 is ensured. Here, the heat exchange tube is arranged at 1/3-1/2 of the first housing 51, and a 1/2-2/3 gas phase space is left at the upper part.

In the present embodiment, the first oil return ports 52 have three, including a first upper oil return port 521 provided at the position where the first casing 51 is flush with the refrigerant liquid surface, a first lower oil return port 522 provided at the bottom of the first casing 51, and a first middle oil return port 523 provided between the first upper oil return port 521 and the first lower oil return port 522. The flooded refrigeration system further comprises a first oil return pipe 53 communicated with the first oil return port 52 and a first regulating valve 54 arranged on the first oil return pipe 53, and the first oil return pipe 53 is communicated with the second pipeline 7. The flooded refrigerating system further comprises a liquid collecting pipe 8 communicated with the flooded evaporator 5, a second oil return port 81 formed in the bottom of the liquid collecting pipe 8, a second oil return pipe 82 communicated with the second oil return port 81, and a second regulating valve 83 arranged on the second oil return pipe 82, wherein the second oil return pipe 82 is communicated with the second pipeline 7. Because the liquid collecting pipe 8 does not participate in heat exchange, the pipe is relatively calm, and an oil return port is arranged below the pipe. The flooded refrigeration system further comprises a third pipeline 9 communicated between the liquid collecting pipe 8 and the flooded evaporator 5, and a first stop valve 10 arranged on the third pipeline 9, wherein a liquid level switch 11 and a liquid level transmitter 12 are arranged on the liquid collecting pipe 8.

By setting the first regulating valve 54 and the second regulating valve 83, the flow rates of the first oil return port 52 and the second oil return port 81 can be regulated to a reasonable state

In this embodiment, the condenser 3 includes a second housing 31, and a condensation tube (not shown in the figure) disposed in the second housing 31, two ends of the condensation tube are respectively connected to the cold source inlet 32 and the cold source outlet 33, the regenerator 6 and the condenser 3 are disposed in the same housing, and the regenerator includes a regenerator tube 61 penetrating through the second housing 31, and the regenerator tube 61 is connected to the second pipeline 7. The low-temperature low-pressure refrigerant in the heat recovery tube 61 exchanges heat with the medium-temperature high-pressure refrigerant outside the tube and is gasified by arranging the heat regenerator 6 and the condenser 3 with the shell, and the medium-temperature high-pressure refrigerant liquid outside the tube is used as a low-grade heat source to heat the mixture of the refrigerant liquid and the lubricating oil in the tube, so that the energy recycling is realized. Here, the refrigerant liquid in the second casing 31 is evaporated and absorbed at the bottom by the refrigerant in the heat recovery pipe 61, and supercooling is realized, thereby reducing the flash quantity after the expansion valve 4, compensating the refrigerant participating in circulation in the oil return operation, compensating the work done by the refrigerant participating in circulation compressed by the compressor 2 in the oil return operation, and improving the effective circulation quantity. Meanwhile, the heat regenerator 6 and the condenser 3 are arranged in the same shell, so that the whole system is compact in structure, low in cost and convenient to popularize.

In this embodiment, the flooded refrigeration system further includes a second stop valve 13, a first filter 14, and a first solenoid valve 15 sequentially disposed on the first pipeline 1 along a direction away from the condenser 3 and toward the flooded evaporator 5, and the expansion valve 4 is disposed between the first solenoid valve 15 and the flooded evaporator 5. The flooded refrigeration system further comprises a third stop valve 16, a second filter 17, a second electromagnetic valve 18 and a first liquid viewing mirror 19 which are sequentially arranged on the second pipeline 7 along the direction away from the flooded evaporator 5 and towards the regenerator 6. The flooded refrigeration system further comprises a second liquid-viewing mirror 20, a third regulating valve 21 and a fourth stop valve 22 which are sequentially arranged on the second pipeline 7 along the direction away from the regenerator 6 and towards the compressor 2.

Here, the second stop valve 13, the third stop valve 16 and the fourth stop valve 22 are used as maintenance partitions, the first filter 14 and the second filter 17 are used for filtering impurities, the first electromagnetic valve 15 and the second electromagnetic valve 18 are used for automatically controlling through electric control, and the requirements of oil return time and oil return interval corresponding to different systems and different working conditions of the system are met through controlling the valve body switch. The second liquid mirror 20 is used for observing whether the refrigerant is completely liquefied and whether oil returns to the compressor, and the third regulating valve 21 is used for regulating the back pressure.

The working procedure of this embodiment is specifically described below: when the working is started, the compressor 2 outputs high-temperature and high-pressure refrigerant gas, the high-temperature and high-pressure refrigerant gas enters the condenser 3 and is condensed into medium-temperature and high-pressure refrigerant liquid in the heat exchange process with the cold source, then the medium-temperature and high-pressure refrigerant liquid is changed into low-temperature and low-pressure refrigerant liquid through the action of the expansion valve 4, then the low-temperature and low-pressure refrigerant liquid enters the flooded evaporator 5 and continuously absorbs heat and evaporates in the heat exchange process with the heat source, the evaporated refrigerant vapor returns to the compressor 2 to complete the cycle, and the refrigeration is realized in the cycle. Meanwhile, in the process of refrigeration cycle, the mixture of low-temperature low-pressure refrigerant liquid and lubricating oil in the flooded evaporator 5 flows out of the flooded evaporator 5 and enters the heat return pipe 61 through the first oil return port 52 and the second oil return port 81 under the action of gravity, the refrigerant is heated and gasified in the heat return pipe 61 by medium-temperature high-pressure refrigerant liquid in the shell of the external condenser 3, the volume of the refrigerant in the heat return pipe 61 expands after being gasified, and the lubricating oil mixed in the refrigerant vapor is flushed into the air suction port of the compressor 2 by the refrigerant vapor to realize oil return operation.

The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and to implement the same, but are not intended to limit the scope of the present invention, and all equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of the present invention.

Claims

1. The utility model provides a flooded refrigerating system, includes compressor (2), condenser (3), expansion valve (4) and the evaporimeter that communicate in proper order through first pipeline (1), its characterized in that: the evaporator is a flooded evaporator (5) and comprises a first shell (51) for storing a refrigerant, a plurality of first oil return ports (52) formed in the first shell (51) and a plurality of heat exchange pipes which are arranged in the first shell (51) and are used for leading in and out a heat source, wherein at least one heat exchange pipe is exposed above the liquid level of the refrigerant, the flooded refrigeration system further comprises a heat regenerator (6), and the heat regenerator (6) is communicated with the first oil return ports (52) and the compressor (2) through a second pipeline (7);

the three first oil return ports (52) comprise a first upper oil return port (521) arranged on the first shell (51) and flush with the refrigerant liquid level, a first lower oil return port (522) arranged at the bottom of the first shell (51) and a first middle oil return port (523) arranged between the first upper oil return port (521) and the first lower oil return port (522);

the condenser (3) comprises a second shell (31) and a condensing tube arranged in the second shell (31), two ends of the condensing tube are respectively communicated with a cold source inlet (32) and a cold source outlet (33), the heat regenerator (6) and the condenser (3) are arranged with the shell, the heat regenerator comprises a heat return tube (61) penetrating through the second shell (31), and the heat return tube (61) is communicated with the second pipeline (7).

2. A flooded refrigeration system as in claim 1 wherein: the flooded refrigerating system further comprises a first oil return pipe (53) communicated with the first oil return opening (52), and a first regulating valve (54) arranged on the first oil return pipe (53), and the first oil return pipe (53) is communicated with the second pipeline (7).

3. A flooded refrigeration system as in claim 1 wherein: the flooded refrigerating system further comprises a liquid collecting pipe (8) communicated with the flooded evaporator (5), a second oil return port (81) formed in the bottom of the liquid collecting pipe (8), a second oil return pipe (82) communicated with the second oil return port (81), and a second regulating valve (83) arranged on the second oil return pipe (82), wherein the second oil return pipe (82) is communicated with the second pipeline (7).

4. A flooded refrigeration system as claimed in claim 3, wherein: the liquid filling type refrigerating system further comprises a third pipeline (9) communicated between the liquid collecting pipe (8) and the liquid filling type evaporator (5), and a first stop valve (10) arranged on the third pipeline (9), wherein a liquid level switch (11) and a liquid level transmitter (12) are arranged on the liquid collecting pipe (8).

5. A flooded refrigeration system as in claim 1 wherein: the flooded refrigeration system further comprises a second stop valve (13), a first filter (14) and a first electromagnetic valve (15) which are sequentially arranged on the first pipeline (1) along the direction away from the condenser (3) and close to the flooded evaporator (5), and the expansion valve (4) is arranged between the first electromagnetic valve (15) and the flooded evaporator (5).

6. A flooded refrigeration system as in claim 1 wherein: the flooded refrigerating system further comprises a third stop valve (16), a second filter (17), a second electromagnetic valve (18) and a first liquid viewing mirror (19) which are sequentially arranged on the second pipeline (7) along the direction away from the flooded evaporator (5) and close to the heat regenerator (6).

7. A flooded refrigeration system as in claim 1 wherein: the flooded refrigerating system further comprises a second liquid-viewing mirror (20), a third regulating valve (21) and a fourth stop valve (22) which are sequentially arranged on the second pipeline (7) along the direction away from the heat regenerator (6) and close to the compressor (2).