Control system for preventing return air of refrigeration compressor from carrying liquid

Abstract

The utility model discloses a control system for preventing return air of a refrigeration compressor from carrying liquid, which comprises a unit, a plurality of compressors are arranged on the unit, one side of the unit is communicated with a return air collecting pipe, and a liquid level meter is arranged on the return air collecting pipe. The other side of the unit is communicated with an air cooler, and the air cooler is communicated with a return air collecting pipe; effective stock of a liquid refrigerant in a return air collecting pipe can be visually sensed through a liquid level meter additionally arranged on the return air collecting pipe of the refrigeration equipment, and the compressor is controlled through an equipment master control program to avoid the problems that 1, the tail end load fluctuation is large, the system reaction lags behind, 2, the expansion valve reaction lags behind after a system shutdown instruction is given, 3, an evaporator frosts, and 4, the system operation lags behind. And therefore, the situation that the compressor and the whole refrigerating system work unstably is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of refrigeration, in particular to a control system for preventing return air from carrying liquid in a refrigeration compressor. Background Art

[0002] One of the prerequisites for ensuring the stable operation of the refrigeration compressor is to ensure that the refrigeration compressor has a reasonable suction or exhaust superheat, and the premise for ensuring a reasonable superheat is that the return air of the refrigeration compressor cannot work with liquid. At present, the refrigeration unit of the cold storage project generally adopts a parallel design of refrigeration compressors, and the terminal evaporator is designed in multiple groups. For example, in the following cases: 1. The terminal load fluctuates greatly and the system response lags 2. After the system shutdown command is issued, the expansion valve reacts lags 3. The evaporator is frosted and the defrost is not timely, etc., the refrigerant liquid that has not been completely evaporated will gather along the system return air pipe to the return air manifold of the refrigeration unit. With the increase in the amount of liquid refrigerant accumulated in the return air manifold, the refrigeration compressor is in a liquid-carrying working state, and the liquid-carrying working has a serious impact on the stability of the refrigeration unit and the entire refrigeration system. If the amount of liquid refrigeration in the return air manifold can be intuitively perceived, the degree of damage to the system caused by liquid compression can be alleviated through system control.

[0003] Therefore, a control system is proposed to prevent return air from carrying liquid in the refrigeration compressor. Summary of the invention

[0004] The utility model aims to provide a control system for preventing return air from carrying liquid in a refrigeration compressor, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the utility model provides the following technical solutions: a control system for preventing return air from carrying liquid from a refrigeration compressor, comprising a unit, a plurality of compressors being installed on the unit, a return air manifold being connected to one side of the unit, and a liquid level meter being installed on the return air manifold;

[0006] The other side of the unit is connected to a cooling fan, and the cooling fan is connected to the return air header.

[0007] Preferably, the unit is connected to the return air header via a first return air pipe.

[0008] Preferably, the unit is connected to the air cooler via a liquid supply pipe.

[0009] Preferably, the air cooler is connected to the return air header via a second return air pipe.

[0010] Preferably, the liquid level meter is used to detect the liquid content inside the return air manifold and feed it back to the main control.

[0011] Preferably, the unit controls the opening and closing of the compressor and the air cooler.

[0012] Compared with the prior art, the beneficial effects of the utility model are as follows: by installing a liquid level meter on the return air manifold of the refrigeration equipment, the effective stock of liquid refrigerant in the return air manifold can be intuitively sensed, and the compressor can be controlled by the equipment master control program to avoid the return air carrying liquid caused by situations such as 1. large fluctuations in terminal load and delayed system response 2. delayed response of the expansion valve after the system shutdown command is issued 3. frosting on the evaporator and failure to defrost in time, thereby avoiding unstable operation of the compressor and the entire refrigeration system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a system schematic diagram of the utility model.

[0014] In the figure: 1. unit; 2. compressor; 3. air cooler; 4. return air header; 5. liquid level meter; 6. first return air pipe; 7. liquid supply pipe; 8. second return air pipe. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Example

[0016] See also Figure 1 The utility model provides a technical solution: a control system for preventing return air from carrying liquid from a refrigeration compressor, comprising a unit 1, a plurality of compressors 2 are installed on the unit 1, a return air manifold 4 is connected to one side of the unit 1, and a liquid level meter 5 is installed on the return air manifold 4;

[0017] The other side of the unit 1 is connected to a cooling fan 3 , and the cooling fan 3 is connected to a return air header 4 .

[0018] like Figure 1 As shown: the unit 1 is connected to the return air manifold 4 through the first return air pipe 6, the unit 1 is connected to the air cooler 3 through the liquid supply pipe 7, and the air cooler 3 is connected to the return air manifold 4 through the second return air pipe 8; through the above settings, multiple devices are connected through pipelines to facilitate overall operation.

[0019] like Figure 1 As shown: the liquid level meter 5 is used to detect the liquid content inside the return air manifold 4 and feed it back to the main control, and the unit 1 controls the opening and closing of the compressor 2 and the air cooler 3; through the above settings, when the liquid level meter 5 detects that the liquid level is high, the unit 1 only turns on the compressor 2, and when the liquid level meter 5 detects that the liquid level drops to a certain level, the air cooler 3 is turned on.

[0020] Working principle: The effective amount of liquid refrigerant in the return air manifold 4 can be intuitively sensed by the liquid level meter 5 installed on the return air manifold 4 of the refrigeration equipment. There are three levels of liquid level display on the liquid level meter 5: low level, medium level, and high level. When the system receives the startup command, the equipment master control program controller will collect the actual liquid level on the current liquid level meter 5. If the current liquid level is at a high level, the refrigeration equipment will not be started, and an alarm signal will be sent to the equipment management personnel in the form of a short message to perform drainage. After the drainage is completed manually, the control program alarm signal disappears, and the program executes the startup program. The system detects the liquid level in real time. During the operation of the system, if the liquid level is high due to 1. large fluctuations in the terminal load and delayed system response 2. delayed response of the expansion valve after the system shutdown command is issued 3. frosting on the evaporator and failure to defrost in time, the current liquid level is at a high level. At this time, the control program executes an alarm fault shutdown process; if the liquid level is at a medium level, the program inspects the warehouse temperature of each cold room, and through temperature comparison, it specifically shuts down the liquid supply of some cold air fans. When closing the liquid supply solenoid valves one by one, the control program monitors the system pressure and temperature. The pressure and temperature must be stable and meet the set requirements before shutting down another cold air fan. Through this solution of stopping the liquid supply of some cold air fans, the liquid refrigerant in the return air manifold 4 can be further vaporized through the refrigeration compressor. When the liquid level of the liquid level gauge 5 reaches a low level, the system re-scans the warehouse temperature of each cold room, and opens the cold air fans one by one in a targeted manner according to the warehouse temperature.

[0021] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A control system for preventing return air from carrying liquid from a refrigeration compressor, comprising a unit (1), characterized in that: The unit (1) is equipped with a plurality of compressors (2); one side of the unit (1) is connected to a return air header (4); and a liquid level meter (5) is installed on the return air header (4); The other side of the unit (1) is connected to a cooling fan (3), and the cooling fan (3) is connected to a return air header (4).

2. A control system for preventing return air from carrying liquid from a refrigeration compressor according to claim 1, characterized in that: The unit (1) is connected to the return air header (4) via a first return air pipe (6).

3. A control system for preventing return air from carrying liquid from a refrigeration compressor according to claim 1, characterized in that: The unit (1) is connected to the cooling fan (3) via a liquid supply pipe (7).

4. A control system for preventing return air from carrying liquid from a refrigeration compressor according to claim 1, characterized in that: The air cooler (3) and the air return header (4) are connected via a second air return pipe (8).

5. A control system for preventing return air from carrying liquid from a refrigeration compressor according to claim 1, characterized in that: The liquid level meter (5) is used to detect the liquid content inside the return air header (4) and feed it back to the main control.

6. A control system for preventing return air from carrying liquid from a refrigeration compressor according to claim 1, characterized in that: The unit (1) controls the opening and closing of the compressor (2) and the cooling fan (3).

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