Refrigeration system for increasing the amount of low-temperature refrigeration

Abstract

The utility model discloses a kind of refrigeration systems for increasing low-temperature refrigeration capacity, belong to refrigeration technical field.The system includes the refrigeration main circuit of compressor, condenser, evaporator etc..Its innovation is to add a heat recovery loop, the liquid side of the heat recovery unit is connected in series between condenser and liquid storage tank, and the gas side is connected in series between evaporator and gas-liquid separator through electric ball valve one and electric ball valve two connected in parallel with it.By controlling the opening and closing of two electric ball valves, the system can intelligently switch operating modes: under ultra-low temperature operating conditions of-30℃ and below, the heat recovery unit is enabled to supercool liquid refrigerant and increase gas return superheat, thereby significantly increasing refrigeration capacity and energy efficiency;Under higher temperature operating conditions, the heat recovery unit is bypassed to reduce resistance.The utility model also includes auxiliary branches such as intercooling and liquid injection, and replaces the vulnerable solenoid valve with an electric ball valve, which collectively achieves the comprehensive benefits of improving low-temperature refrigeration performance, enhancing system reliability and reducing operating noise.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration technology, specifically to a refrigeration system that increases the low-temperature cooling capacity. Background Technology

[0002] In the field of industrial refrigeration, especially in applications requiring ultra-low temperature environments of -30°C and below, traditional refrigeration systems face two major challenges: First, at such low evaporation temperatures, the system's cooling capacity and coefficient of performance (COP) decrease significantly, leading to increased energy consumption and poor cooling performance. Second, to control complex refrigeration circuits, liquid injection cooling, and hot gas bypass, multiple solenoid valves are required in the system. These solenoid valves need to be opened and closed frequently, and long-term operation not only easily generates noise, but their internal electromagnetic coils and moving iron cores are also prone to damage due to fatigue and wear, affecting the stability and service life of the entire system.

[0003] Therefore, there is an urgent need in this field for a refrigeration system solution that can effectively improve cryogenic cooling capacity, enhance the reliability of key valve components, and reduce operating noise. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a refrigeration system that increases the cooling capacity at low temperatures. Through structural optimization, this system can significantly improve the cooling capacity and energy efficiency under ultra-low temperature conditions, while also being more stable in operation, quieter, and with a longer lifespan.

[0005] Therefore, this utility model proposes a refrigeration system to increase low-temperature cooling capacity, including a compressor, an oil-gas separator, a condenser, a liquid receiver, a dryer filter, a refrigeration expansion valve, and an evaporator. The compressor, condenser, and evaporator are connected sequentially through pipelines to form a refrigeration main circuit. It also includes a regenerative circuit, which includes a regenerator, an electric ball valve one, and an electric ball valve two; the refrigerant liquid flow channel of the regenerator is connected in series in the pipeline between the outlet of the condenser and the inlet of the liquid storage tank; the refrigerant gas flow channel of the regenerator is connected in series in the pipeline between the outlet of the evaporator and the inlet of the gas-liquid separator. The first electric ball valve is connected in series with the gas flow channel of the regenerator; the second electric ball valve is connected in parallel with the gas flow channel of the regenerator, forming a bypass flow path that allows the refrigerant gas to bypass the regenerator.

[0006] Furthermore, the system also includes an intercooling branch, which includes an intercooler, an intercooling expansion valve, and an intercooling solenoid valve; the main channel of the intercooler is connected in series in the main refrigeration circuit between the dryer filter and the refrigeration expansion valve.

[0007] Furthermore, the inlet end of the intercooler branch is connected to the pipeline on the outlet side of the dryer filter, and after passing through the intercooler solenoid valve and the intercooler expansion valve in sequence, it is connected to the inlet of the heat exchange channel of the intercooler. The outlet of the heat exchange channel of the intercooler is connected to the intermediate gas injection port of the compressor through a pipeline.

[0008] Furthermore, the system also includes a liquid spraying branch, which includes a liquid spraying solenoid valve and a liquid spraying expansion valve connected in sequence.

[0009] Furthermore, the inlet end of the spray branch is connected to the liquid pipe on the outlet side of the liquid storage tank, and the outlet end is connected to the suction pipe of the compressor or the compressor housing.

[0010] Furthermore, the system also includes a refrigeration bypass, which comprises a bypass solenoid valve and a capillary tube connected in series.

[0011] Furthermore, the refrigeration bypass is connected in parallel between the high-pressure pipeline on the outlet side of the oil-gas separator and the low-pressure pipeline on the inlet side of the refrigeration expansion valve.

[0012] Furthermore, the system also includes a pressure control branch, which includes a low-pressure indicator, a high / low pressure control indicator, and a high-pressure indicator, used to monitor and control the operating pressure of the system.

[0013] Furthermore, in the system, at least the refrigeration solenoid valve used to control the on / off state of the regenerative circuit is an electric ball valve.

[0014] The refrigeration system for increasing low-temperature cooling capacity provided by this utility model has the following beneficial effects.

[0015] 1. By adding a regenerator, the cold energy of the system return gas is used to subcool the high-pressure liquid refrigerant under ultra-low temperature conditions, which significantly increases the unit cooling capacity after throttling. At the same time, the superheat of the return gas is improved, making the compressor work more efficiently, thereby improving the overall cooling capacity and energy efficiency of the system at -30℃ and below.

[0016] 2. Replace the easily damaged solenoid valves in key parts of the system with electric ball valves. By utilizing the characteristics of electric ball valves, such as low flow resistance, high opening and closing torque, and low wear, the valve operation noise is greatly reduced, the failure caused by frequent opening and closing is reduced, and the service life of the core valve components of the system is extended.

[0017] 3. Through the coordinated control of electric ball valves one and two, the system can intelligently switch whether to enable the regeneration function according to actual needs (such as setting the temperature above or below -20℃). While ensuring ultra-low temperature performance, it avoids unnecessary pressure loss caused by the regenerator under normal operating conditions, so that the system always remains in the high-efficiency operating range.

[0018] 4. By combining the intercooling branch, the liquid injection branch, and the pressure control branch, a multi-level protection and energy efficiency improvement mechanism is formed, ensuring the stability and safety of the system under wide temperature range and high load conditions.

[0019] In addition to the purposes, features, and advantages described above, this application has other purposes, features, and advantages. A further detailed description of this application will be provided below with reference to the figures. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the refrigeration system for increasing low-temperature cooling capacity according to this utility model; Explanation of reference numerals in the attached diagram: 1. Compressor; 2. Outlet shock absorber pipe; 3. Oil-gas separator; 4. Condenser; 5. Liquid receiver; 6. Dryer filter; 7. Refrigeration solenoid valve; 8. Refrigeration expansion valve; 9. Bypass solenoid valve; 10. Capillary tube; 11. Evaporator; 12. Electric ball valve one; 13. Liquid injection solenoid valve; 14. Liquid injection expansion valve; 15. Gas-liquid separator; 16. Return shock absorber pipe; 17. Low pressure indicator; 18. High and low pressure control; 19. High pressure indicator; 20. Electric ball valve two; 21. Intercooler solenoid valve; 22. Sight glass; 23. Intercooler expansion valve; 24. Intercooler; 25. Intercooler shock absorber pipe; 26. Regenerator. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] like Figure 1 As shown, the refrigeration system for increasing low-temperature cooling capacity of this utility model includes: a refrigeration circuit, a regenerative circuit, a liquid injection branch, a refrigeration bypass, a pressure control branch, and an intercooling branch. The refrigeration circuit is the basic circulation path of the system. The refrigerant is discharged from the compressor 1 and passes sequentially through the outlet shock absorber 2, oil-gas separator 3, shell and tube condenser 4, liquid side passage of regenerator 26, liquid receiver 5, dryer filter 6, main passage of intercooler 24, refrigeration solenoid valve 7, refrigeration expansion valve 8, evaporator 11, and then enters the selection channel of the regenerator circuit. Finally, it returns to the compressor 1 through gas-liquid separator 15 and return gas shock absorber 16 to complete the cycle.

[0023] The regenerative circuit is one of the core innovations of this invention. It consists of a regenerator 26, an electric ball valve 12, and an electric ball valve 20. The liquid side of the regenerator 26 is connected in series between the shell-and-tube condenser 4 and the liquid storage tank 5 for subcooling the high-pressure liquid. Its gas side is connected in series between the outlet of the evaporator 11 and the inlet of the gas-liquid separator 15. The electric ball valve 12 is connected in series with this gas side channel, while the electric ball valve 20 is directly connected in parallel to both ends of the gas side of the regenerator 26, forming a bypass pipeline.

[0024] When the system set temperature is -30℃ or below (requiring increased low-temperature cooling capacity), the control system will open electric ball valve 12 and simultaneously close electric ball valve 20. The low-temperature, low-pressure refrigerant return gas from the evaporator 11 will flow entirely through the gas-side passage of the regenerator 26. Inside the regenerator 26, this cold return gas exchanges heat with the relatively high-temperature liquid refrigerant flowing from the shell-and-tube condenser 4, which is heading towards the liquid receiver 5. As a result, the liquid refrigerant is significantly subcooled, thereby improving its cooling efficiency in the evaporator; while the return gas is heated, increasing its superheat, which is beneficial for the safe and efficient operation of the compressor 1.

[0025] When the system set temperature is above -20℃ (normal low-temperature operation), the control system will close electric ball valve 12 and simultaneously open electric ball valve 20. At this time, the return gas will bypass the regenerator 26 and directly enter the gas-liquid separator 15 through the bypass path formed by electric ball valve 20. This avoids increasing unnecessary flow resistance under conditions where extremely high cooling capacity is not required, ensuring system efficiency.

[0026] The intercooler branch is used to further improve system energy efficiency. A portion of high-pressure liquid refrigerant is drawn from the dryer filter 6 and flows sequentially through the intercooler solenoid valve 21, sight glass 22, and intercooler expansion valve 23 for throttling. It then enters the heat exchange side of the intercooler 24 to evaporate and absorb heat, absorbing the heat of the liquid refrigerant flowing through the main channel of the intercooler 24, thus deeply subcooling it. The evaporated medium-pressure gas returns to the intermediate gas injection port of the compressor 1 through the intercooler vibration damping pipe 25.

[0027] The liquid injection branch is used for cooling protection of compressor 1. When the discharge temperature of compressor 1 is detected to be too high, the liquid injection solenoid valve 13 opens, and the liquid refrigerant drawn from the liquid storage tank 5 is throttled by the liquid injection expansion valve 14 and directly injected into the suction pipe or casing of compressor 1 to quickly reduce its operating temperature.

[0028] The refrigeration bypass consists of a bypass solenoid valve 9 and a capillary tube 10 connected in series and in parallel between the high-pressure side (after the oil-gas separator 3) and the low-pressure side (before the evaporator 11) of the system. When the system is unloaded, shut down, or defrosting, the bypass solenoid valve 9 opens, and through the throttling effect of the capillary tube 10, it balances the high and low pressure difference of the system, assists in energy regulation, and protects the compressor.

[0029] The pressure control branch displays the system pressure in real time through the low pressure indicator 17 and the high pressure indicator 19, and the high and low pressure controller 18 automatically cuts off the circuit to protect the system when the pressure exceeds the safe range.

[0030] This invention, through the optimized combination of the above structures, especially the innovative application of the regenerative circuit and the electric ball valve, successfully achieves multiple objectives: improving cryogenic cooling capacity, enhancing system reliability, and reducing operating noise.

[0031] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A refrigeration system for increasing low-temperature cooling capacity, characterized in that, include: The system includes a compressor (1), an oil-gas separator (3), a condenser (4), a liquid receiver (5), a dryer filter (6), a refrigeration expansion valve (8), and an evaporator (11). The compressor (1), condenser (4), and evaporator (11) are connected in sequence through pipelines to form the main refrigeration circuit. It also includes a regenerative circuit, which includes a regenerator (26), an electric ball valve one (12), and an electric ball valve two (20); the refrigerant liquid flow channel of the regenerator (26) is connected in series in the pipeline between the outlet of the condenser (4) and the inlet of the liquid storage tank (5); the refrigerant gas flow channel of the regenerator (26) is connected in series in the pipeline between the outlet of the evaporator (11) and the inlet of the gas-liquid separator (15); The electric ball valve one (12) is connected in series with the gas flow channel of the regenerator (26); the electric ball valve two (20) is connected in parallel with the gas flow channel of the regenerator (26), forming a bypass flow path that allows the refrigerant gas to bypass the regenerator (26).

2. The refrigeration system for increasing low-temperature cooling capacity according to claim 1, characterized in that, The system also includes an intercooler branch, which includes an intercooler (24), an intercooler expansion valve (23), and an intercooler solenoid valve (21); the main channel of the intercooler (24) is connected in series in the main refrigeration circuit between the dryer filter (6) and the refrigeration expansion valve (8).

3. The refrigeration system for increasing low-temperature cooling capacity according to claim 2, characterized in that, The inlet end of the intercooling branch is connected to the pipeline on the outlet side of the dryer filter (6), and after passing through the intercooling solenoid valve (21) and the intercooling expansion valve (23) in sequence, it is connected to the heat exchange channel inlet of the intercooler (24). The heat exchange channel outlet of the intercooler (24) is connected to the intermediate gas supply port of the compressor (1) through a pipeline.

4. The refrigeration system for increasing low-temperature cooling capacity according to claim 1, characterized in that, The system also includes a liquid spraying branch, which includes a liquid spraying solenoid valve (13) and a liquid spraying expansion valve (14) connected in sequence.

5. The refrigeration system for increasing low-temperature cooling capacity according to claim 4, characterized in that, The inlet end of the spray branch is connected to the liquid pipe on the outlet side of the liquid storage tank (5), and the outlet end is connected to the suction pipe of the compressor (1) or the compressor housing.

6. The refrigeration system for increasing low-temperature cooling capacity according to claim 1, characterized in that, The system also includes a refrigeration bypass, which includes a bypass solenoid valve (9) and a capillary tube (10) connected in series.

7. The refrigeration system for increasing low-temperature cooling capacity according to claim 6, characterized in that, The refrigeration bypass is connected in parallel between the high-pressure pipeline on the outlet side of the oil-gas separator (3) and the low-pressure pipeline on the inlet side of the refrigeration expansion valve (8).

8. The refrigeration system for increasing low-temperature cooling capacity according to claim 1, characterized in that, The system also includes a pressure control branch, which includes a low-pressure indicator (17), a high and low pressure control (18), and a high-pressure indicator (19) for monitoring and controlling the operating pressure of the system.

9. The refrigeration system for increasing cryogenic cooling capacity according to any one of claims 1 to 8, characterized in that, In the system, at least the refrigeration solenoid valve (7) used to control the on / off state of the regenerative circuit is an electric ball valve.

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