Liquid backflushing prevention structure for refrigerating system
By combining components such as low-temperature compressors and medium-temperature evaporators with control valves, the system prevents liquid backflow when the refrigeration system stops, thus solving the refrigerant liquid backflow problem and achieving cost and space savings as well as system safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- PANASONIC APPLIANCES REFRIGERATION SYST DALIAN CO LTD
- Filing Date
- 2025-03-05
- Publication Date
- 2026-05-19
AI Technical Summary
When the refrigeration system is shut down, the refrigerant liquid can easily flow back into the unit's liquid receiver. Traditional methods of increasing the volume of the liquid receiver lead to wasted cost and space.
It adopts a combination design of components such as low temperature compressor, medium temperature evaporator, air cooler, parallel heat exchanger, flash tank and anti-liquid backflow pipeline, and controls liquid flow through liquid supply check valve and bypass shut-off valve to prevent liquid backflow.
It effectively prevents refrigerant backflow, saves manufacturing costs and space, and ensures safe system operation.
Smart Images
Figure CN224261999U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of liquid supply pipeline technology for refrigeration systems, and in particular to a structure for preventing liquid backflow in refrigeration systems. Background Technology
[0002] With the booming development of the frozen and refrigerated industry, the number of cold storage facilities and supermarkets is growing rapidly. From large-scale logistics cold storage warehouses to fresh food supermarket refrigerated display cases in neighborhoods, their operating scenarios are becoming increasingly complex and diverse.
[0003] On the one hand, site selection is often constrained by factors such as urban planning, rental costs, and transportation convenience. This makes it difficult for many cold storage facilities and supermarkets to guarantee ideal terrain conditions during construction, with the terminal site frequently being higher than the refrigeration unit. On the other hand, the working principle of the refrigeration system dictates that at the moment of shutdown, the refrigerant gas-liquid balance is disrupted, and under the influence of gravity, a large amount of liquid refrigerant can easily flow back into the unit's liquid receiver. The traditional solution is simply to increase the volume of the liquid receiver, which significantly increases the cost of the receiver itself and the land area required.
[0004] Therefore, this utility model patent proposes a structural design for preventing liquid backflow in a refrigeration system. Utility Model Content
[0005] This invention provides a structure for preventing liquid backflow in a refrigeration system, which solves the problem of a large amount of refrigerant liquid backflowing into the unit's liquid receiver.
[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0007] A structure for preventing liquid backflow in a refrigeration system includes a cryogenic compressor and a medium-temperature evaporator. The cryogenic compressor and the medium-temperature evaporator are connected to the suction end of the medium-temperature compressor via pipes. The discharge end of the medium-temperature compressor is connected to the inlet end of an air cooler. The liquid outlet end of the air cooler is connected to a parallel heat exchanger. The parallel heat exchanger is connected to the liquid inlet end of a flash tank. The liquid outlet end of the flash tank is connected to the medium-temperature evaporator and the cryogenic evaporator via anti-liquid backflow pipes.
[0008] Furthermore, the liquid outlet end of the flash tank is connected to the liquid inlet manifold of the anti-liquid backflow pipe via a pipeline, and the liquid inlet manifold is connected to the liquid outlet manifold via a first pipeline, and a liquid supply check valve is respectively installed on the first pipeline.
[0009] Furthermore, the anti-liquid backflow pipeline is also provided with a return drainage pipeline, the two ends of which are respectively connected to the liquid inlet manifold and the liquid outlet manifold, and a bypass shut-off valve is provided on the return drainage pipeline.
[0010] Furthermore, the parallel heat exchanger is connected to the liquid inlet of the flash tank via a second pipe, and a regulating valve is installed on the second pipe; the gas outlet of the flash tank is connected to the gas inlet of the parallel heat exchanger, the gas outlet of the parallel heat exchanger is connected to the suction end of the parallel compressor, and the exhaust end of the parallel compressor is connected to the oil separator.
[0011] Furthermore, the oil separator is installed on the pipeline connecting the medium-temperature compressor and the air cooler.
[0012] Furthermore, the liquid outlet manifold is connected to a medium-temperature evaporator and a low-temperature evaporator via pipes, wherein a low-temperature regenerator is installed on the pipe connected to the low-temperature evaporator.
[0013] Furthermore, the inlet end of the low-temperature regenerator is connected to the liquid outlet end of the manifold, the outlet end of the low-temperature regenerator is connected to the inlet end of the low-temperature evaporator, and the outlet end of the low-temperature evaporator is connected to the suction end of the low-temperature compressor via the low-temperature regenerator.
[0014] The beneficial effects of this utility model are as follows:
[0015] This invention prevents refrigerant backflow during shutdown and saves on manufacturing and space costs associated with increasing container size. It also ensures the safe operation of the entire system. Attached Figure Description
[0016] To more clearly illustrate the embodiments of this utility model or the technical solutions of the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the structure of this utility model.
[0018] Explanation of icon numbers:
[0019] 1. Medium-temperature compressor; 2. Parallel compressor; 3. Oil separator; 4. Air cooler; 5. Parallel heat exchanger; 6. Flash tank; 7. Liquid backflow prevention pipeline; 71. Liquid supply check valve; 8. Medium-temperature evaporator; 9. Low-temperature regenerator; 10. Low-temperature evaporator; 11. Low-temperature compressor; 12. Regulating valve. Detailed Implementation
[0020] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.
[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this utility model or its application or use. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0022] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this utility model.
[0023] This utility model provides a technical solution: a structure for preventing liquid backflow in a refrigeration system, such as... Figure 1 As shown, it includes a medium-temperature compressor 1, a parallel compressor 2, an oil separator 3, an air cooler 4, a parallel heat exchanger 5, a flash tank 6, a backflow prevention pipeline 7, a medium-temperature evaporator 8, a low-temperature regenerator 9, a low-temperature evaporator 10, a low-temperature compressor 11, and a regulating valve 12.
[0024] The low-temperature compressor 11 and the medium-temperature evaporator 8 are connected to the suction end of the medium-temperature compressor 1 through pipes. The discharge end of the medium-temperature compressor 1 is connected to the inlet end of the air cooler 4. The liquid outlet end of the air cooler 4 is connected to the parallel heat exchanger 5. The parallel heat exchanger 5 is connected to the liquid inlet end of the flash tank 6 through a second pipe. A regulating valve 12 is installed on the second pipe. The liquid outlet end of the flash tank 6 is connected to the liquid inlet manifold of the anti-liquid backflow pipeline 7 through a pipe. The liquid inlet manifold is connected to the liquid outlet manifold through a first pipe. A liquid supply check valve 71 is installed on several first pipes. A return pipeline is also installed in the anti-liquid backflow pipeline 7. The two ends of the return pipeline are connected to the liquid inlet manifold and the liquid outlet manifold, respectively. A bypass shut-off valve is installed on the return pipeline.
[0025] The outlet of the flash tank 6 is connected to the inlet of the parallel heat exchanger 5. The outlet of the parallel heat exchanger 5 is connected to the oil separator 3 via the parallel compressor 2. The oil separator 3 is installed on the pipeline connecting the medium-temperature compressor 1 and the air cooler 4.
[0026] The liquid outlet manifold is connected to the medium-temperature evaporator 8 and the low-temperature evaporator 10 via pipes. A low-temperature regenerator 9 is installed on the pipe connected to the low-temperature evaporator 10. The liquid inlet of the low-temperature regenerator 9 is connected to the liquid outlet manifold, and the liquid outlet of the low-temperature regenerator 9 is connected to the liquid inlet of the low-temperature evaporator 10. The gas outlet of the low-temperature evaporator 10 is connected to the suction end of the low-temperature compressor 11 via the low-temperature regenerator 9.
[0027] The work process is as follows:
[0028] First, the low-temperature compressor 11 draws in the low-temperature refrigerant and compresses it into refrigerant gas. This gas mixes with the refrigerant gas evaporated in the medium-temperature evaporator 8 and enters the suction end of the medium-temperature compressor 1. The medium-temperature compressor 1 then compresses this gas into a high-temperature, high-pressure refrigerant gas. This high-temperature, high-pressure refrigerant gas then passes through the gas cooler 4 to become a low-temperature, high-pressure refrigerant gas. Finally, this low-temperature, high-pressure refrigerant gas passes through the parallel heat exchanger 5 and the regulating valve 12, becoming a low-temperature, medium-pressure liquid refrigerant, which then enters the flash tank 6. The liquid refrigerant in the flash tank 6 enters the liquid inlet manifold of the anti-backflow pipeline 7 and then passes through the liquid supply check valve 71 into the liquid outlet manifold. The liquid outlet manifold supplies the liquid refrigerant to both the medium-temperature evaporator 8 and the low-temperature evaporator 10. The refrigerant gas evaporated in the low-temperature evaporator returns to the suction end of the low-temperature compressor 11 via the low-temperature regenerator 9. The flash gas in the flash tank 6 passes through the parallel heat exchanger 5 and returns to the suction end of the parallel compressor 2. The parallel compressor 2 then compresses this gas into a high-temperature, high-pressure gas, which enters the oil separator 3, thus completing the entire refrigeration process.
[0029] When the evaporator stops working, the liquid refrigerant remaining in the evaporator will backflow into the flash tank 6 due to gravity, posing a significant risk to the system. However, the liquid backflow check valve 71 prevents this backflow. Conversely, if liquid refrigerant needs to be manually discharged back into the flash tank 6 for maintenance of the terminal evaporator, the bypass shut-off valve 72 in the backflow prevention line can be opened to recover the liquid refrigerant into the flash tank.
[0030] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and inventive concept of the present utility model, should be included within the protection scope of the present utility model.
Claims
1. A structure for preventing liquid backflow in a refrigeration system, characterized in that, It includes a low-temperature compressor (11) and a medium-temperature evaporator (8). The low-temperature compressor (11) and the medium-temperature evaporator (8) are connected to the suction end of the medium-temperature compressor (1) through pipes. The discharge end of the medium-temperature compressor (1) is connected to the inlet end of the air cooler (4). The liquid outlet end of the air cooler (4) is connected to the parallel heat exchanger (5). The parallel heat exchanger (5) is connected to the liquid inlet end of the flash tank (6). The liquid outlet end of the flash tank (6) is connected to the medium-temperature evaporator (8) and the low-temperature evaporator (10) respectively through a backflow prevention pipeline (7).
2. The structure for preventing liquid backflow in a refrigeration system according to claim 1, characterized in that, The outlet end of the flash tank (6) is connected to the liquid inlet manifold of the anti-liquid backflow pipeline (7) through a pipe. The liquid inlet manifold is connected to the liquid outlet manifold through a first pipe. A liquid supply check valve (71) is provided on the first pipe.
3. The structure for preventing liquid backflow in a refrigeration system according to claim 2, characterized in that, The anti-liquid backflow pipeline (7) is also provided with a return pipeline, the two ends of which are respectively connected to the liquid inlet manifold and the liquid outlet manifold, and a bypass shut-off valve is provided on the return pipeline.
4. The structure for preventing liquid backflow in a refrigeration system according to claim 1, characterized in that, The parallel heat exchanger (5) and the flash tank (6) are connected by a second pipe, and a regulating valve (12) is provided on the second pipe; the outlet of the flash tank (6) is connected to the inlet of the parallel heat exchanger (5), the outlet of the parallel heat exchanger (5) is connected to the suction end of the parallel compressor (2), and the exhaust end of the parallel compressor (2) is connected to the oil separator (3).
5. The structure for preventing liquid backflow in a refrigeration system according to claim 4, characterized in that, The oil separator (3) is installed on the pipeline connecting the medium-temperature compressor (1) and the air cooler (4).
6. The structure for preventing liquid backflow in a refrigeration system according to claim 2, characterized in that, The liquid outlet manifold is connected to the medium-temperature evaporator (8) and the low-temperature evaporator (10) respectively via pipes, wherein a low-temperature regenerator (9) is installed on the pipe connected to the low-temperature evaporator (10).
7. The structure for preventing liquid backflow in a refrigeration system according to claim 6, characterized in that, The inlet end of the low-temperature regenerator (9) is connected to the liquid outlet end manifold, the outlet end of the low-temperature regenerator (9) is connected to the inlet end of the low-temperature evaporator (10), and the outlet end of the low-temperature evaporator (10) is connected to the suction end of the low-temperature compressor (11) through the low-temperature regenerator (9).