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CN-122015307-A - Refrigerating system, air supplementing method of refrigerating system and stop control method

CN122015307ACN 122015307 ACN122015307 ACN 122015307ACN-122015307-A

Abstract

The invention provides a refrigerating system, an air supplementing method of the refrigerating system and a stopping control method, wherein the refrigerating system comprises a compressor, an oil separator, a condenser, a liquid accumulator, an economizer, a main liquid accumulator and an evaporator, wherein the compressor is provided with a first-stage air suction port, a middle air supplementing port and an air exhaust port, a liquid supply pipeline is formed from the main liquid accumulator to the evaporator, the air suction pipeline is led out from the evaporator to the first-stage air suction port of the compressor, an inter-cooling pipeline is led out from the economizer to the middle air supplementing port of the compressor, a first detection unit for detecting the liquid supply amount in the main liquid accumulator is arranged at the main liquid accumulator, a flash bypass pipeline is arranged between the main liquid accumulator and the compressor, a flash bypass electromagnetic valve and a flash bypass expansion valve are arranged on the flash bypass pipeline, when the liquid storage amount in the main liquid accumulator is lower than a set value, the flash bypass electromagnetic valve is started, the flash bypass expansion valve starts to work, and when the liquid storage amount in the main liquid accumulator reaches the set value, the flash bypass electromagnetic valve is closed, and the flash bypass expansion valve stops working.

Inventors

  • LIU JIE
  • Tao Liuqian
  • YU SUSU
  • CAO DEYUN
  • WANG YONG

Assignees

  • 四方科技集团股份有限公司

Dates

Publication Date
20260512
Application Date
20260302

Claims (10)

  1. 1. A refrigeration system, characterized by: The device comprises a compressor (1), an oil separator (2), a condenser (3), a liquid reservoir (4), an economizer (5), a main liquid collector (7) and an evaporator (11) which are sequentially connected, wherein the compressor (1) is provided with a primary air suction port, an intermediate air supplementing port and an air exhaust port, a liquid supply pipeline (101) is formed from the main liquid collector (7) to the evaporator (11), an air suction pipeline (102) is led out of the evaporator (11) and connected to the primary air suction port of the compressor (1), and an intermediate air supplementing port is led out of the economizer (5) and connected to the compressor (1); A first detection unit (8) for detecting the liquid supply amount in the main liquid collector (7) is arranged at the position of the main liquid collector (7), a flash bypass pipeline (105) is arranged between the main liquid collector (7) and a primary air suction port of the compressor (1), a flash bypass electromagnetic valve (12) and a flash bypass expansion valve (13) are arranged on the flash bypass pipeline (105), when the first detection unit (8) detects that the liquid supply amount of the main liquid collector (7) is lower than a set value, the flash bypass electromagnetic valve (12) is controlled to be opened, the flash bypass expansion valve (13) starts to work, and when the first detection unit (8) detects that the liquid supply amount in the main liquid collector (7) reaches the set value, the flash bypass electromagnetic valve (12) is controlled to be closed, and the flash bypass expansion valve (13) stops working.
  2. 2. A refrigeration system as set forth in claim 1 wherein: an intercooler bypass pipeline (106) is arranged between an intercooler gas outlet of the economizer (5) and a primary air suction port of the compressor (1), and an intercooler bypass electromagnetic valve (14) is arranged on the intercooler bypass pipeline (106).
  3. 3. A refrigeration system as set forth in claim 2 wherein: An intermediate liquid storage unit is arranged between the main liquid collector (7) and the evaporator (11), the intermediate liquid storage unit comprises a high-level liquid collector (16) and a second detection unit (17) for detecting liquid supply amount of the high-level liquid collector (16), the high-level liquid collector (16) is close to the evaporator (11), a first main path cut-off electromagnetic valve (15) is arranged between the high-level liquid collector (16) and the main liquid collector (7), and a second main path cut-off electromagnetic valve (18) is arranged between the high-level liquid collector (16) and the evaporator (11).
  4. 4. A refrigeration system as set forth in claim 3 wherein: a main-way electromagnetic valve (9) and a main-way expansion valve (10) are arranged between the main-way liquid collector (7) and the evaporator (11), and the intermediate liquid storage unit is arranged between the main-way electromagnetic valve (9) and the main-way expansion valve (10).
  5. 5. The refrigeration system of claim 4, wherein: A pressure detection unit (20) is arranged on a suction pipeline (102) connecting the evaporator (11) and the compressor (1), and the pressure detection unit (20) is used for detecting the pressure at a primary air suction port of the compressor (1).
  6. 6. The refrigeration system of claim 4, wherein: The high-level liquid collector (16) is further provided with a third detection unit (19), the second detection unit (17) is used for detecting the high liquid level liquid supply amount of the high-level liquid collector (16), and the third detection unit (19) is used for detecting the low liquid level liquid supply amount of the high-level liquid collector (16).
  7. 7. A method for supplementing air to a refrigeration system, characterized by comprising the following steps based on the refrigeration system according to any one of claims 4 to 6: S1, opening the intercooling bypass electromagnetic valve (14) to supplement the refrigerant gas of the economizer (5) into a primary air suction port of the compressor (1); S2, when the first detection unit (8) detects that the liquid supply amount of the refrigerant in the main liquid collector (7) is lower than a set liquid supply value, the flash bypass electromagnetic valve (12) is opened, and flash gas in the liquid supply pipeline (101) is throttled, depressurized and supplemented to a first-stage air suction port of the compressor (1); S3, when the first detection unit (8) detects that the liquid supply amount of the refrigerant in the main liquid collector (7) reaches a set liquid supply value, the flash bypass electromagnetic valve (12) and the intercooling bypass electromagnetic valve (14) are closed.
  8. 8. A method for supplementing air to a refrigeration system according to claim 7, Step S0 is further provided before step S1, and step S0 is: The refrigerating system is started, the first main path cut-off electromagnetic valve (15) and the second main path cut-off electromagnetic valve (18) are opened, the refrigerant in the high-order liquid collector (16) flows into the liquid supply pipeline (101) and the evaporator (11), and after the starting condition of the compressor (1) is met, the compressor (1) is started.
  9. 9. A method for supplementing air to a refrigeration system according to claim 8, The starting condition of the compressor (1) in the step S0 is that the third detection unit (19) detects that the liquid level in the high-level liquid collector (16) reaches a low liquid level, or the pressure detection unit (20) detects that the pressure at the primary air suction port of the compressor (1) reaches a starting set value.
  10. 10. A stop control method of a refrigeration system according to claim 4, characterized in that the method is based on the refrigeration system as follows: When the refrigerating system is stopped, the second main path cut-off electromagnetic valve (18) is closed, and when the second detection unit (17) detects that the refrigerant in the high-order liquid collector (16) reaches the set liquid supply amount, the first main path cut-off electromagnetic valve (15) is closed, and the compressor (1) is closed.

Description

Refrigerating system, air supplementing method of refrigerating system and stop control method Technical Field The invention relates to the technical field of refrigeration systems, in particular to a refrigeration system, an air supplementing method and a stopping control method of the refrigeration system. Background In refrigeration systems, because of the constraints of the installation site, the quick-freezing equipment may be located higher than the refrigeration unit skid (typically consisting of a compressor, oil separator, condenser, accumulator, economizer, accumulator, and connecting piping), and the refrigeration piping is long. After shutdown, refrigerant liquid can fall back to the reservoir of refrigeration unit sled piece because of gravity effect, when equipment was turned on again, because refrigeration unit sled piece had the difference in height and refrigeration pipeline is longer with the evaporimeter, and the refrigerant can't get into the evaporimeter fast, leads to suction pressure to be too low, causes refrigeration unit warning shut down, and the evaporimeter can't normal operating cooling. The compressor runs for a long time under the condition of low suction pressure, so that the exhaust temperature is easy to rise suddenly, the energy efficiency is easy to drop, and lubricating oil is carbonized and coked when serious, and the compressor bearing is worn and damaged. In order to rapidly raise the suction pressure, a path of gas is usually led out from the exhaust pipeline, and is depressurized through the expansion valve and then is connected into the suction pipeline of the compressor, so that the suction pressure is rapidly supplemented. However, the high-temperature and high-pressure gas in the exhaust pipeline is depressurized and then enters the compressor for compression, so that adverse phenomena such as overhigh exhaust temperature and overheating of the compressor are easily caused, and particularly for a single-machine two-stage compressor, after the gas is compressed by the two-stage compressor, the stability of the whole refrigerating system can be influenced due to overhigh exhaust temperature. In addition, in a direct expansion refrigeration system, a large amount of flash gas is easily generated after the refrigerant liquid is throttled and depressurized by an expansion valve. The flash gas enters the evaporator to reduce the heat exchange efficiency of the refrigerant liquid, and the liquid supply pipeline is long, the trend is complex, the bending is more, the height difference exists, and new flash gas is easy to form in the reflux process, so that the refrigerating capacity of the system is reduced, and the energy consumption is increased. Therefore, in such a refrigerating system in which the quick-freezing equipment is higher than the position of the skid block of the refrigerating unit due to the limitation of the installation site, a refrigerating system capable of quickly supplementing pressure when the equipment is started needs to be designed. Disclosure of Invention The invention aims to provide a refrigeration system, an air supplementing method and a stopping control method of the refrigeration system, so as to solve the problems. The technical scheme adopted by the invention is as follows: The refrigerating system comprises a compressor, an oil separator, a condenser, a liquid accumulator, an economizer, a main liquid collector and an evaporator which are sequentially connected, wherein the compressor is provided with a first-stage air suction port, an intermediate air supplementing port and an air exhaust port, a liquid supply pipeline is formed from the main liquid collector to the evaporator, an air suction pipeline is led out from the evaporator and connected to the first-stage air suction port of the compressor, and an intermediate air supplementing port is led out from the economizer and connected to the compressor; The liquid storage device comprises a main path liquid collector, a first detection unit, a flash bypass electromagnetic valve, a flash bypass expansion valve and a first detection unit, wherein the first detection unit is used for detecting liquid supply amount in the main path liquid collector, the flash bypass pipeline is arranged between the main path liquid collector and a first-stage air suction port of a compressor, the flash bypass electromagnetic valve and the flash bypass expansion valve are arranged on the flash bypass pipeline, when the first detection unit detects that the liquid supply amount of the main path liquid collector is lower than a set value, the flash bypass electromagnetic valve is controlled to be opened, the flash bypass expansion valve starts to work, and when the first detection unit detects that the liquid supply amount in the main path liquid collector reaches the set value, the flash bypass electromagnetic valve is controlled to be closed, and the flash bypass expansion valve stops working. As a fur