Defrosting device for parallel units

Abstract

The defrosting device comprises a machine frame, screw compressors are installed on the top of the machine frame at equal intervals, the output ends of the screw compressors are communicated with a buffer pipe, the output end of the buffer pipe is communicated with a liquid storage tank, a condenser is arranged on one side of the liquid storage tank, and the condenser is connected with the screw compressors. The input end and the output end of the condenser are both communicated with first pressure regulating valves, the first pressure regulating valve located at the input end of the condenser is communicated with a liquid storage tank, and the first pressure regulating valve located at the output end of the condenser is communicated with a connecting pipe. The utility model relates to the technical field of parallel unit refrigeration equipment, and solves the problems that in the prior art, the defrosting efficiency is low when electric heating pipes arranged in an air cooler are used for heating fins, the defrosting electric heating pipes are large in power and high in energy consumption, and if the quality of the heating pipes is poor or the heating pipes are used for a long time, the heating pipes are easy to burn out and even cause fire disasters. And serious potential safety hazards exist.

Description

Technical Field

[0001] The utility model relates to the technical field of parallel unit refrigeration equipment, in particular to a defrosting device for parallel units. Background Technique

[0002] A parallel unit refers to connecting two or more refrigeration compressors together to jointly bear the load and share the work. This configuration can improve the total capacity and efficiency of the system, make the system more stable and reliable, have a common evaporation pressure and condensation pressure, can automatically adjust the energy according to the load of the system, realize the uniform wear of the compressors, improve the working efficiency of the system and the service life of the equipment, and save energy. Due to long-term operation and the influence of the external environment, the surface of the evaporator of the parallel unit refrigeration equipment is prone to frosting, which affects the heat exchange efficiency. In the prior art, the fin is heated by the electric heating tubes arranged in the air cooler, and the defrosting efficiency is low, and the power of the defrosting electric heating tubes is very large, resulting in high energy consumption. If the quality of the heating tubes is not good or after long-term use, they are easily burned out or even cause a fire, posing a serious safety hazard. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the utility model provides a defrosting device for parallel units, which solves the problems in the prior art that the fin is heated by the electric heating tubes arranged in the air cooler, the defrosting efficiency is low, the power of the defrosting electric heating tubes is very large, resulting in high energy consumption, and if the quality of the heating tubes is not good or after long-term use, they are easily burned out or even cause a fire, posing a serious safety hazard.

[0004] To achieve the above object, the utility model is realized through the following technical solutions: A defrosting device for a parallel unit, including a frame. The top of the frame is equidistantly installed with screw compressors. The output end of the screw compressor is connected to a buffer pipe. The output end of the buffer pipe is connected to a liquid storage tank. One side of the liquid storage tank is provided with a condenser. The input end and the output end of the condenser are both connected to a first pressure regulating valve. The first pressure regulating valve located at the input end of the condenser is connected to the liquid storage tank. The first pressure regulating valve located at the output end of the condenser is connected to a connecting pipe. The end of the connecting pipe away from the condenser is connected to an evaporator. An expansion valve is installed at the end of the connecting pipe close to the evaporator. A gas transfer pump is installed on the top of the frame. The input end and the output end of the gas transfer pump are both connected to a transfer pipe. The transfer pipe located at the output end of the gas transfer pump is connected to the end of the connecting pipe close to the evaporator. The transfer pipe located at the input end of the gas transfer pump is connected to the output end of the evaporator. First solenoid valves are installed on the outer walls of both transfer pipes. A pressure regulating valve is installed on the transfer pipe located at the output end of the gas transfer pump. The output end of the evaporator is connected to a second solenoid valve. The end of the second solenoid valve away from the evaporator is connected to the input end of the screw compressor. A controller is installed on one side of the frame. The screw compressor, the gas transfer pump, the first solenoid valve and the second solenoid valve are all electrically connected to the controller.

[0005] Preferably, oil separators are connected to the sides of the buffer pipe and the liquid storage tank close to each other. The output end of the liquid storage tank is connected to a drying filter. The output end of the drying filter is connected to the first pressure regulating valve. The end of the second solenoid valve away from the evaporator is connected to a return air filter. The side of the return air filter away from the second solenoid valve is connected to a gas-liquid separator. The gas-liquid separator is respectively connected to the input ends of the screw compressor and the gas transfer pump.

[0006] Preferably, second pressure regulating valves are installed at the output ends of the gas-liquid separator and are connected to the screw compressor.

[0007] Preferably, pressure transmitters are installed on the tops of the liquid storage tank and the gas-liquid separator and are electrically connected to the controller.

[0008] Preferably, temperature sensors are installed on one side of the condenser and the evaporator and are electrically connected to the controller.

[0009] The present utility model provides a defrosting device for a parallel unit, which has the following beneficial effects: The defrosting device for the parallel unit, through a frame, a connecting pipe, an evaporator, a first pressure regulating valve, a gas delivery pump, a delivery pipe, a first solenoid valve, a pressure regulating valve and a controller, sets the defrosting time interval through the controller. When the defrosting time is reached, the controller automatically shuts down the screw compressor and stops the heat exchange cycle of the medium. The relatively high-temperature gaseous medium is re-input into the evaporator through the gas delivery pump, which can increase the temperature of the heat exchange pipes of the evaporator. After a certain period of circulation, the frost condensed on the surface of the heat exchange pipes can be melted, enabling the device to perform automatic defrosting operations at fixed time intervals. By recycling the waste heat discharged from the evaporator, energy loss can be reduced. By increasing the temperature of the heat exchange pipes and melting the frost inside, larger frost blocks can be separated more quickly, which helps to improve the efficiency and safety of the defrosting operation of the refrigeration equipment.

[0010] Through the cooperation among a liquid storage tank, an evaporator, an oil separator, a suction gas filter, a gas-liquid separator, a dryer filter and a buffer pipe, by separating oil from the high-pressure medium input to the condenser, drying and filtering it, and filtering and separating gas and liquid from the high-temperature medium output from the evaporator, the medium can be in a clean, dry and stable state in the system, thereby ensuring the efficient and stable operation of the entire refrigeration system, further avoiding a large accumulation of frost at a certain place in the evaporator, improving the defrosting efficiency, and ensuring the smooth progress of the defrosting operation, so that the refrigeration equipment can avoid generating a large accumulation of frost. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic structural diagram of the present utility model;

[0012] Figure 2 is Figure 1 a partial enlarged view of area A in

[0013] Figure 3 is Figure 1 a partial enlarged view of area B in

[0014] In the figure: 1, frame; 2, screw compressor; 3, condenser; 4, liquid storage tank; 5, connecting pipe; 6, evaporator; 7, first pressure regulating valve; 8, gas delivery pump; 9, delivery pipe; 10, first solenoid valve; 11, pressure regulating valve; 12, second solenoid valve; 13, controller; 14, oil separator; 15, suction gas filter; 16, gas-liquid separator; 17, dryer filter; 18, buffer pipe; 19, second pressure regulating valve; 20, pressure transmitter; 21, temperature sensor; 22, expansion valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0016] In the prior art, the electric heating tubes arranged in the air cooler are used to heat the fins, the defrosting efficiency is low, and the power of the defrosting electric heating tubes is very large, resulting in high energy consumption. If the quality of the heating tubes is not good or after long-term use, they are easily burned out or even cause a fire, posing serious safety hazards.

[0017] In view of this, the present invention provides a defrosting device for a parallel unit, which includes a frame, a connecting pipe, an evaporator, a first pressure regulating valve, a gas delivery pump, a delivery pipe, a first solenoid valve, a pressure regulating valve and a controller. The controller sets the defrosting time interval. When the defrosting time is reached, the controller automatically shuts down the screw compressor to stop the heat exchange cycle of the medium. The gas delivery pump re-injects the relatively high-temperature gaseous medium into the evaporator to increase the temperature of the heat exchange tubes of the evaporator. After a certain period of circulation, the frost condensed on the surface of the heat exchange tubes is melted, realizing the automatic defrosting operation of the equipment. By recycling the waste heat discharged from the evaporator, the energy loss is reduced. By increasing the temperature of the heat exchange tubes, the frost melts inside, enabling larger frost blocks to be separated more quickly and improving the safety of the defrosting operation of the equipment.

[0018] Those skilled in the art connect all the electrical components in this case to their adapted power supplies through wires, and should select appropriate controllers and encoders according to the actual situation to meet the control requirements. For the specific connection and control sequence, reference should be made to the working principle below, and the electrical connection should be completed according to the sequential working order among the electrical components. The detailed connection means are well-known techniques in the art. The following mainly introduces the working principle and process, and no further description of the electrical control will be given.

[0019] From Figures 1-3It can be seen that the defrosting device for a parallel unit includes a frame 1. Screw compressors 2 are equidistantly installed at the top of the frame 1. The output end of the screw compressor 2 is connected to a buffer pipe 18. The output end of the buffer pipe 18 is connected to a liquid storage tank 4. A condenser 3 is arranged on one side of the liquid storage tank 4. The input end and the output end of the condenser 3 are both connected to a first pressure regulating valve 7. The first pressure regulating valve 7 located at the input end of the condenser 3 is connected to the liquid storage tank 4. The first pressure regulating valve 7 located at the output end of the condenser 3 is connected to a connecting pipe 5. The end of the connecting pipe 5 away from the condenser 3 is connected to an evaporator 6. An expansion valve 22 is installed at the end of the connecting pipe 5 close to the evaporator 6. The expansion valve 22 controls the valve flow through the superheat change at the end of the evaporator, so as to ensure that the outlet of the evaporator 6 is completely gaseous refrigerant, prevent insufficient utilization of the area of the evaporator 6 and knocking phenomenon, and maintain the stable operation of the refrigeration system. A gas transfer pump 8 is installed at the top of the frame 1. The input end and the output end of the gas transfer pump 8 are both connected to a transfer pipe 9. The transfer pipe 9 located at the output end of the gas transfer pump 8 is connected to the end of the connecting pipe 5 close to the evaporator 6. The transfer pipe 9 located at the input end of the gas transfer pump 8 is connected to the output end of the evaporator 6. First solenoid valves 10 are installed on the outer walls of both transfer pipes 9. A pressure regulating valve 11 is installed on the transfer pipe 9 located at the output end of the gas transfer pump 8. The output end of the evaporator 6 is connected to a second solenoid valve 12. The second solenoid valve 12 is used to control the opening and closing of the pipeline at the output end of the evaporator 6. The end of the second solenoid valve 12 away from the evaporator 6 is connected to the input end of the screw compressor 2. A controller 13 is installed on one side of the frame 1. The screw compressor 2, the gas transfer pump 8, the first solenoid valves 10 and the second solenoid valve 12 are all electrically connected to the controller 13;

[0020] In the specific implementation process, it is particularly worth noting that the frame 1 is used to install and fix the components of the parallel unit. The screw compressor 2 is used to compress the medium. Through the cooperation among the screw compressor 2, the condenser 3, the liquid storage tank 4, the connecting pipe 5 and the evaporator 6, they are all the main components of the parallel unit. The pressurized medium is transported to the liquid storage tank 4 by the screw compressor 2, and the high-pressure gas is transported to the condenser 3 through the liquid storage tank 4 to cool and liquefy the medium, and the heat generated by liquefaction is conducted to the external environment. The liquefied medium is transported to the evaporator 6 through the connecting pipe 5 and is converted from liquid to gas in the evaporator 6, absorbing the heat in the environment during the conversion process. The converted gaseous medium is re-sucked into the screw compressor 2 for compression, thus completely realizing the refrigeration cycle. Through the cooperation among the screw compressor 2, the liquid storage tank 4 and the buffer pipe 18, the high-pressure gas output by the screw compressor 2 is collected through the buffer pipe 18. The high-pressure gas generated by the screw compressor 2 directly impacts the liquid storage tank 4, thereby extending the service life of the equipment. And through the volume effect of the liquid storage tank 4, the high-pressure gas is preliminarily stabilized and stored to prevent the liquid medium generated by compression from entering the condenser 3. Moreover, the first pressure regulating valve 7 is used to adjust the medium pressure input and output by the condenser 3 to ensure the heat exchange efficiency of the condenser 3. The expansion valve 22 controls the valve flow through the superheat change at the end of the evaporator, thereby ensuring that the outlet of the evaporator 6 is completely gaseous refrigerant, preventing insufficient utilization of the evaporator 6 area and knocking phenomenon, and maintaining the stable operation of the refrigeration system. The second solenoid valve 12 is used to control the opening and closing of the pipeline at the output end of the evaporator 6. Through the cooperation among the connecting pipe 5, the evaporator 6, the first pressure regulating valve 7, the gas delivery pump 8, the delivery pipe 9, the first solenoid valve 10, the pressure regulating valve 11 and the controller 13, the defrosting time interval is set by the controller 13. When the defrosting time is reached, the controller 13 automatically shuts down the screw compressor 2, stops the heat exchange cycle of the medium, and opens the first solenoid valve 10 and the gas delivery pump 8 to re-transport the relatively high-temperature gaseous medium discharged from the evaporator 6 to the inside of the evaporator 6. The heat is conducted to the evaporator 6 through the high-temperature gaseous medium, melting the frost on the surface of the evaporator 6 from the inside. And after the set time, the refrigeration cycle of the refrigeration equipment is automatically restored. Through the frame 1, the connecting pipe 5, the evaporator 6, the first pressure regulating valve 7, the gas delivery pump 8, the delivery pipe 9, the first solenoid valve 10, the pressure regulating valve 11 and the controller 13, the defrosting time interval is set by the controller 13. When the defrosting time is reached, the controller 13 automatically shuts down the screw compressor 2, stops the heat exchange cycle of the medium, and re-inputs the relatively high-temperature gaseous medium into the evaporator 6 through the gas delivery pump 8 to increase the temperature of the heat exchange pipes of the evaporator 6. After a certain period of circulation, the frost condensed on the surface of the heat exchange pipes melts, realizing the automatic defrosting operation of the equipment. By recycling and utilizing the waste heat discharged from the evaporator 6, the energy loss is reduced. By increasing the temperature of the heat exchange pipes, the frost melts from the inside.Enable larger frost blocks to be separated more quickly and improve the safety of the defrosting operation of the equipment. The specific models of the screw compressor 2, the first pressure regulating valve 7, the gas transfer pump 8, the first solenoid valve 10, the second solenoid valve 12, and the controller 13 are not limited, as long as they meet the usage requirements;

[0021] It can be understood that the number of screw compressors 2 can be two or more. They are connected to the pipeline system in the same connection manner, and the operating quantity can be adjusted according to actual needs. The refrigerating capacity can be flexibly adjusted according to the load change, making the refrigeration system operate more stably and efficiently.

[0022] Furthermore, oil separators 14 are connected to both sides of the buffer pipe 18 and the liquid storage tank 4 that are close to each other. The output end of the liquid storage tank 4 is connected to a drying filter 17, and the output end of the drying filter 17 is connected to the first pressure regulating valve 7. The end of the second solenoid valve 12 away from the evaporator 6 is connected to a suction filter 15, and the side of the suction filter 15 away from the second solenoid valve 12 is connected to a gas-liquid separator 16. The gas-liquid separator 16 is respectively connected to the input ends of the screw compressor 2 and the gas transfer pump 8;

[0023] In the specific implementation process, it is particularly worth noting that through the cooperation among the liquid storage tank 4, the oil separator 14, the drying filter 17, and the buffer pipe 18, the oil in the high-pressure medium output by the screw compressor 2 is separated by the oil separator 14, and then the separated high-pressure medium is dried by the drying filter 17 to remove the moisture and impurities therein, ensuring the purity and dryness of the high-pressure medium. Through the cooperation among the evaporator 6, the suction filter 15, and the gas-liquid separator 16, the high-temperature gaseous medium output by the evaporator 6 is filtered and separated into gas and liquid to remove the moisture and liquid therein. Through the cooperation among the liquid storage tank 4, the evaporator 6, the oil separator 14, the suction filter 15, the gas-liquid separator 16, the drying filter 17, and the buffer pipe 18, by separating the oil, drying and filtering the high-pressure medium input to the condenser 3, and filtering and separating the gas-liquid of the high-temperature medium output by the evaporator 6, the medium is made to be in a clean, dry and stable state in the system, thereby ensuring the efficient and stable operation of the entire refrigeration system, avoiding a large amount of accumulated frosting at a certain place of the evaporator 6, and further improving the defrosting efficiency and ensuring the smooth progress of the defrosting operation process;

[0024] Furthermore, second pressure regulating valves 19 are installed at the output ends of the gas-liquid separators 16, and the second pressure regulating valves 19 are connected to the screw compressors 2;

[0025] In the specific implementation process, it is particularly worth noting that through the cooperation among the screw compressor 2, the gas-liquid separator 16, and the second pressure regulating valve 19, by controlling the second pressure regulating valve 19, the pipeline at the input end of the screw compressor 2 can be opened and closed, and the input pressure of the screw compressor 2 can be adjusted, enabling the parallel unit to adjust the operating state of the equipment according to the usage requirements. During the defrosting operation, by closing the second pressure regulating valve 19, the parallel unit can be switched from the refrigeration cycle mode to the defrosting mode, improving the convenience of the defrosting operation;

[0026] Furthermore, pressure transmitters 20 are installed at the tops of both the liquid storage tank 4 and the gas-liquid separator 16, and the pressure transmitters 20 are electrically connected to the controller 13;

[0027] In the specific implementation process, it is particularly worth noting that through the cooperation among the liquid storage tank 4, the gas-liquid separator 16, and the pressure transmitter 20, the pressures in the liquid storage tank 4 and the gas-liquid separator 16 are measured, facilitating the parallel unit to monitor the operating state of the equipment. The specific model of the pressure transmitter 20 is not limited, as long as it meets the usage requirements;

[0028] Furthermore, temperature sensors 21 are installed on one side of both the condenser 3 and the evaporator 6, and the temperature sensors 21 are electrically connected to the controller 13;

[0029] In the specific implementation process, it is particularly worth noting that the temperature sensor 21 is used to measure the temperature of the medium transported to the condenser 3 and the evaporator 6, and transmit the temperature signal to the controller 13 in real time, facilitating the controller 13 to judge the defrosting progress according to the temperature change of the medium in the evaporator 6. The specific model of the temperature sensor 21 is not limited, as long as it meets the usage requirements.

[0030] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation. An element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0031] In the present utility model, unless otherwise clearly stipulated and defined, terms such as "installation", "setting", "connection", "fixation", "swivel connection", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. Unless otherwise clearly defined, for those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0032] Although the embodiments of the present utility model have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A defrosting device for a parallel unit, comprising a frame (1), characterized in that: Screw compressors (2) are equidistantly mounted on the top of the frame (1); the output end of the screw compressor (2) is connected to a buffer tube (18); the output end of the buffer tube (18) is connected to a liquid storage tank (4); a condenser (3) is arranged on one side of the liquid storage tank (4); the input end and the output end of the condenser (3) are both connected to a first pressure regulating valve (7); the first pressure regulating valve (7) located at the input end of the condenser (3) is connected to the liquid storage tank (4); the first pressure regulating valve (7) located at the output end of the condenser (3) is connected to a connecting pipe (5); the end of the connecting pipe (5) away from the condenser (3) is connected to an evaporator (6); the end of the connecting pipe (5) close to the evaporator (6) is mounted with an expansion valve (22); a gas delivery pump (8) is mounted on the top of the frame (1); the input end and the output end of the gas delivery pump (8) are both connected to A delivery pipe (9) is provided, wherein the delivery pipe (9) located at the output end of the gas delivery pump (8) is connected to an end of the connecting pipe (5) close to the evaporator (6), and the delivery pipe (9) located at the input end of the gas delivery pump (8) is connected to the output end of the evaporator (6). A first solenoid valve (10) is installed on the outer wall of each of the two delivery pipes (9). A pressure regulating valve (11) is installed on the delivery pipe (9) located at the output end of the gas delivery pump (8). The output end of the evaporator (6) is connected to a second solenoid valve (12), and an end of the second solenoid valve (12) away from the evaporator (6) is connected to the input end of the screw compressor (2). A controller (13) is installed on one side of the frame (1), and the screw compressor (2), the gas delivery pump (8), the first solenoid valve (10) and the second solenoid valve (12) are all electrically connected to the controller (13).

2. The defrosting device for a parallel unit according to claim 1, characterized in that: The buffer pipe (18) and the liquid storage tank (4) are both connected to an oil separator (14) on the side close to each other; the output end of the liquid storage tank (4) is connected to a drying filter (17); the output end of the drying filter (17) is connected to a first pressure regulating valve (7); the end of the second solenoid valve (12) away from the evaporator (6) is connected to a return air filter (15); the side of the return air filter (15) away from the second solenoid valve (12) is connected to a gas-liquid separator (16); the gas-liquid separator (16) is respectively connected to the input ends of the screw compressor (2) and the gas delivery pump (8).

3. The defrosting device for a parallel unit according to claim 2, characterized in that: A second pressure regulating valve (19) is installed at the output end of the gas-liquid separator (16), and the second pressure regulating valve (19) is connected to the screw compressor (2).

4. The defrosting device for a parallel unit according to claim 2, characterized in that: A pressure transmitter (20) is installed on the top of the liquid storage tank (4) and the gas-liquid separator (16), and the pressure transmitter (20) is electrically connected to the controller (13).

5. The defrosting device for a parallel unit according to claim 1, characterized in that: A temperature sensor (21) is installed on one side of the condenser (3) and the evaporator (6), and the temperature sensor (21) is electrically connected to the controller (13).

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