CN216347286U

CN216347286U - Hot liquid defrosting system

Info

Publication number: CN216347286U
Application number: CN202122816173.9U
Authority: CN
Inventors: 杨建国; 周成君; 康建慧; 王全江; 谢伟波; 张继龙; 赵辉; 张伟; 曾献廷; 李军赠; 晁海英
Original assignee: Beijing Jingkelun Refrigeration Equipment Co ltd
Current assignee: Beijing Jingkelun Refrigeration Equipment Co ltd
Priority date: 2021-11-17
Filing date: 2021-11-17
Publication date: 2022-04-19
Anticipated expiration: 2031-11-17

Abstract

The utility model relates to a hot liquid defrosting system which comprises a compressor, a first reversing valve, a condenser, a liquid storage device, a low-pressure circulating barrel and a second reversing valve, wherein the compressor, the first reversing valve, the condenser, the liquid storage device, the low-pressure circulating barrel and the second reversing valve are sequentially communicated through a pipeline; the low-pressure circulating barrel is connected to the circulating pump, the circulating pump is connected to the gas-liquid mixer, the gas-liquid mixer is connected to the evaporator, the evaporator is connected to the low-pressure circulating barrel, and an air inlet port of the gas-liquid mixer is connected with the second reversing valve. The beneficial effects are as follows: only increase a gas-liquid mixer, the system switching-over of refrigeration cycle and defrosting circulation is realized to rethread switching-over valve, just can realize defrosting, uses the gas-liquid two-phase mixed conveyer, makes steam and low pressure circulation bucket liquid mix to send to each terminal evaporimeter heat transfer defrosting after the medium temperature liquid, and this process need not to switch through complicated valve member, and whole process is simple reliable, and is little to the impact of system's pipeline or valve, and is safe high-efficient.

Description

Hot liquid defrosting system

Technical Field

The utility model relates to the field of refrigeration, in particular to a hot liquid defrosting system.

Background

At present, a refrigeration house refrigerating system mostly adopts a large temperature difference cooling mode, the temperature difference between the evaporation temperature and the temperature of the refrigeration house is 10-15 ℃, the operation causes that a tail end evaporator is high in frosting speed, and frequent defrosting operation is needed. Therefore, the defrosting system of the tail end evaporator under the low-temperature working condition, the corresponding method and the control logic are always a big difficulty in the refrigeration industry. The traditional defrosting mode comprises three modes of electric defrosting, hot water spraying defrosting and hot air defrosting, and under the technical idea of safety and energy conservation, the hot air defrosting mode is increasingly applied with high-efficiency defrosting effect. In practical engineering application, in order to ensure safe and efficient operation of hot gas defrosting, the hot gas defrosting mode comprises a three-pipe defrosting mode and a four-pipe defrosting mode, but the two modes all need to be provided with a hot gas inlet pipeline, a defrosting return liquid pipeline and a plurality of control valves separately, and the two modes have the defects of excessive valves, complex control, multiple welded junctions, high failure rate and difficult obstacle removal and maintenance. The steam is that 70 ~ 120 ℃ of steam directly gets into the evaporimeter during the steam defrosting, because gaseous specific heat capacity is little, when the pipe diameter is confirmed, just needs very high gas velocity of flow to satisfy the required heat of defrosting, when defrosting flow control procedure operation is improper, high-pressure high-speed gas can press remaining liquid and strike pipeline or valve fast, causes the pipeline to rock, and sound is unusual, and the serious person takes place the pipeline even and reveals, the case damages, and liquid explodes or the liquid hits the phenomenon and takes place. Moreover, frequent thermal defrosting in the warehouse can cause the leakage of the welded junction of the valve body, repeated thermal expansion and cold contraction can seriously damage the close contact degree of the pipeline and the fins, and the efficiency of the air cooler is reduced, and a series of adverse effects such as large temperature fluctuation in the warehouse and the like are caused.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects of the prior art and provide a hot liquid defrosting system and a defrosting method which have simple system pipelines and simple control and greatly reduce the using number of valve elements.

The utility model provides a hot liquid defrosting system, which adopts the technical scheme that:

a hot liquid defrosting system comprises a compressor, a first reversing valve, a condenser, a liquid storage device, a low-pressure circulating barrel and a second reversing valve which are sequentially communicated through a pipeline; the low-pressure circulating barrel is connected to the circulating pump, the circulating pump is connected to the gas-liquid mixer, the gas-liquid mixer is connected to the evaporator, the evaporator is connected to the low-pressure circulating barrel, and an air inlet port of the gas-liquid mixer is connected with the second reversing valve.

Preferably, the first reversing valve is a four-way reversing valve.

Preferably, the second direction valve is a three-way direction valve.

Preferably, a relief valve and an electronic expansion valve are arranged in parallel on a pipeline between the condenser and the liquid reservoir.

Preferably, a solenoid valve is provided between the accumulator and the low pressure circulation tub.

Preferably, the evaporator is a ceiling fan.

Preferably, the evaporator is a heat exchange bank-pipe.

Preferably, the gas-liquid mixer comprises a liquid refrigerant inlet, a gas refrigerant inlet and a gas-liquid outlet.

Preferably, the condenser is a flash evaporation condenser and comprises a shell, a negative pressure fan and a heat exchange unit, wherein the negative pressure fan is arranged at the top of the shell and used for forming negative pressure in the shell; the heat exchange units are arranged in the shell in a stacked mode and comprise water atomizers, multiple rows of coil pipes for circulating refrigerants and fins for fixing the multiple rows of coil pipes, the multiple rows of coil pipes and the fins are fixed through a fixing frame, and the refrigerants flow in from an inlet end and are discharged from an outlet end; multiple rows of coil pipes of the multiple heat exchange units are connected in series or in parallel; the water atomizer is connected with a water source and is used for atomizing water.

The implementation of the utility model comprises the following technical effects:

according to the hot defrosting system, only one gas-liquid mixer is added, and system reversing of refrigeration cycle and defrosting cycle is realized through the reversing valve, so that defrosting can be realized, a gas-liquid two-phase mixing conveyor is used, hot gas and low-pressure circulation barrel liquid are mixed into medium-temperature liquid (10-30 ℃) and then sent to each tail end evaporator for heat exchange and defrosting, complex valves are not needed for switching in the process, and the whole process is simple, reliable, safe and efficient. Compared with the existing three-pipe defrosting mode and the four-pipe defrosting mode, the novel three-pipe defrosting device has the advantages that control valves are not required to be added, the control is simple, the obstacle removal and the maintenance are easy, and the failure rate is low. The hot defrosting mode of gas-liquid mixing is adopted, the advantage of large specific heat capacity of liquid is utilized, the defrosting temperature difference is small, the damage of the close contact degree between the pipeline and the fins, which is damaged by expansion with heat and contraction with cold, is reduced, and the fluctuation of the temperature in the warehouse can be reduced. The defrosting mode of the utility model has small impact on a system pipeline or a valve, does not generate liquid explosion or liquid impact, and has safe system use and long service life.

Drawings

Fig. 1 is a schematic view of a connection system of a thermal defrosting system in a cooling mode according to an embodiment of the present invention.

Fig. 2 is a schematic view of a connection system of a thermal defrosting system in a defrosting mode according to an embodiment of the present invention.

Fig. 3 is a schematic diagram of a flash condenser structure.

In the figure: 1. a compressor; 2. a first direction changing valve; 3. a condenser; 30. a housing; 31. a negative pressure fan; 32. A heat exchange unit; 33. a water atomizer; 4. an overflow valve; 5. an electronic expansion valve; 6. a reservoir; 7. an electromagnetic valve; 8. a low pressure recycle bin; 9. a circulation pump; 10. a gas-liquid mixer; 11. an evaporator; 12. and a second direction changing valve.

Detailed Description

The present invention will be described in detail below with reference to embodiments and drawings, it being noted that the described embodiments are only intended to facilitate the understanding of the present invention, and do not limit it in any way.

Referring to fig. 1 and 2, the thermal defrosting system provided by the present embodiment includes a compressor 1, a first direction valve 2, a condenser 3, an accumulator 6, a low-pressure circulation tank 8, and a second direction valve 12, which are sequentially communicated with each other through a pipeline; the low-pressure circulation barrel 8 is connected to a circulation pump 9, the circulation pump 9 is connected to a gas-liquid mixer 10, the gas-liquid mixer 10 is connected to an evaporator 11, the evaporator 11 is connected to the low-pressure circulation barrel 8, and an air inlet port of the gas-liquid mixer 10 is connected to a second reversing valve 12.

Referring to fig. 1, in a cooling mode, the exhaust end of the compressor 1 is communicated with the condenser 3 through the first reversing valve 2, the condenser 3 condenses a high-temperature refrigerant into a liquid, the liquid refrigerant flows into the liquid reservoir 6 through the overflow valve 4, the liquid refrigerant in the liquid reservoir 6 flows into the low-pressure circulation barrel 8 through the electromagnetic valve 7, the liquid refrigerant in the low-pressure circulation barrel 8 flows through the evaporator 11 through the circulation pump 9 and the gas-liquid mixer 10, the refrigerant returns to the low-pressure circulation barrel 8 after evaporation and refrigeration, and the refrigerant gas in the low-pressure circulation barrel 8 returns to the suction end of the compressor 1 through the second reversing valve 12 and the first reversing valve 2, so as to form a cooling cycle. In the cooling mode, the connection between the gas-liquid mixer 10 and the second reversing valve 12 is not conducted, that is, the gas-liquid mixer 10 does not intake air, and only functions to circulate the liquid refrigerant.

Referring to fig. 2, in a defrosting mode, the exhaust end of the compressor 1 is communicated with the gas-liquid mixer 10 through the first reversing valve 2 and the second reversing valve 12, the circulating pump 9 mixes refrigerant liquid and high-temperature gas generated at the exhaust end of the compressor 1 into medium-temperature liquid (10-30 ℃) in the gas-liquid mixer 10, and then the medium-temperature liquid is sent to each terminal evaporator 11 for heat exchange and defrosting, a low-temperature refrigeration medium after defrosting returns to the low-pressure circulating barrel 8, and then enters the condenser 3 for heat exchange through the electromagnetic valve 7, the liquid reservoir 6 and the electronic expansion valve 5 in sequence, and then enters the air inlet end of the compressor 1 through the first reversing valve 2, so that a defrosting cycle is formed.

Specifically, the first direction valve 2 is a four-way direction valve, and performs direction change when the refrigeration cycle is switched to the defrosting cycle. The second direction valve 12 is a three-way direction valve, and realizes direction change when the refrigeration cycle is switched to the defrosting cycle. A relief valve 4 and an electronic expansion valve 5 are arranged in parallel on a pipeline between the condenser 3 and the liquid storage 6, and the relief valve 4 is used for guiding the refrigerant liquid condensed by the condenser 3 into the liquid storage 6 under the set pressure condition. In the refrigeration circulation mode, the electronic expansion valve 5 can be opened or closed, but in the defrosting circulation mode, the electronic expansion valve 5 is opened to ensure defrosting circulation. The overflow valve 4 can only realize one-way circulation, has the function of pressure regulation, can keep the pressure in the system in a proper range all the time, and ensures the high-efficiency operation of the system. The electronic expansion valve 5 has the functions of throttling and reducing pressure. An electromagnetic valve 7 is arranged between the liquid reservoir 6 and the low-pressure circulating barrel 8 and is used for controlling the circulation between the liquid reservoir 6 and the low-pressure circulating barrel 8. The evaporator 11 is a ceiling fan or a heat exchange bank-pipe. Referring to fig. 2, the gas-liquid mixer 10 includes a liquid refrigerant inlet, a gas refrigerant inlet, and a gas-liquid outlet, and the high-pressure gas and the low-temperature liquid are quickly mixed under the pressure to obtain a gas-liquid mixture at a corresponding temperature, so that the gas-liquid preparation efficiency can be improved, the preparation device can be simplified, the space can be saved, the investment can be greatly reduced, and the operation cost and the maintenance cost can be saved.

According to the hot defrosting system, only one gas-liquid mixer 10 is added, and system reversing of refrigeration cycle and defrosting cycle is realized through a reversing valve, defrosting can be realized, a gas-liquid two-phase mixing conveyor is used, hot gas and low-pressure circulation barrel 8 liquid are mixed into medium-temperature liquid (10-30 ℃) and then sent to each tail end evaporator 11 for heat exchange and defrosting, complex valves are not needed for switching in the process, and the whole process is simple, reliable, safe and efficient. Compared with the existing three-pipe defrosting mode and the four-pipe defrosting mode, the device does not need to increase excessive control valve pieces, is simple to control, is easy to remove obstacles and maintain, and has low failure rate. The hot defrosting mode of gas-liquid mixing is adopted, the advantage of large specific heat capacity of liquid is utilized, the defrosting temperature difference is small, the damage of the close contact degree between the pipeline and the fins, which is damaged by expansion with heat and contraction with cold, is reduced, and the fluctuation of the temperature in the warehouse can be reduced. The defrosting mode of the utility model has small impact on a system pipeline or a valve, does not generate liquid explosion or liquid impact, and has safe system use and long service life.

As an example, referring to fig. 3, the condenser 3 is a flash condenser, and includes a housing 30, a negative pressure fan 31 and a heat exchange unit 32, the negative pressure fan 31 being disposed at the top of the housing 30 for forming a negative pressure in the housing 30; the heat exchange units 32 are arranged in the shell 30 in a stacked mode, each heat exchange unit 32 comprises a water atomizer 33, a plurality of rows of coil pipes for circulating a refrigerant and fins for fixing the plurality of rows of coil pipes, the plurality of rows of coil pipes and the fins are fixed through a fixing frame, and the refrigerant flows in from an inlet end and is discharged from an outlet end; the multiple rows of coils of the multiple heat exchange units 32 are connected in series or in parallel; the water atomizer 33 is connected to a water source for atomizing water. Atomized water is diffused in the inner cavity of the shell 30, and under the action of negative pressure, the liquid micro-particles and the refrigerant in the rows of coil pipes are extracted out of the shell 30 by the negative pressure fan 31 after completing radiation heat exchange. When refrigerating, the water micelles in the cavity absorb the radiant heat of the refrigerant circulating in the rows of coil pipes, the water micelles are gradually decomposed into small micelles to take away the heat, and the refrigerant is condensed and liquefied. The water micelles are dynamically and continuously decomposed into small water micelles to take away heat. The water vapor after heat exchange is not circulated and recovered and is directly discharged into the atmosphere, and the heat is mainly converted into internal energy in the water micelle decomposition process, so that the discharged water vapor has low temperature and cannot generate a heat island effect. The mode of assembling a plurality of heat exchange units 32 in a stacked manner is convenient to install and maintain, and when a certain heat exchange unit 32 is damaged, the damaged maintenance sheet can be detached for maintenance or replacement. Compared with the existing air-cooled heat exchanger, the flash evaporation condenser exchanges heat in the shell 30, almost does not enter air, and when the external temperature and the humidity are high, the heat exchange effect cannot be influenced by the temperature and the humidity of external natural wind. When defrosting, the condenser plays a role in heating.

The hot defrosting method of the embodiment comprises the following steps: connecting the discharge end of the compressor 1 to the gas refrigerant inlet of the gas-liquid mixer 10 by controlling the first and second

direction changing valves

2 and 12; the circulating pump 9 completes gas-liquid mixing of refrigerant liquid in the low-pressure circulating barrel 8 and high-temperature gas generated at the exhaust end of the compressor 1 in the gas-liquid mixer 10 to form medium-temperature liquid, then the medium is sent to each end evaporator 11 for heat exchange and defrosting, low-temperature refrigeration medium after defrosting returns to the low-pressure circulating barrel 8, then enters the condenser 3 for heat exchange through the electromagnetic valve 7, the liquid storage 6 and the electronic expansion valve 5 in sequence, and the refrigerant enters the air inlet end of the compressor 1 through the first reversing valve 2 to form defrosting circulation.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A hot liquid defrosting system comprises a compressor, a first reversing valve, a condenser, a liquid storage device, a low-pressure circulating barrel and a second reversing valve which are sequentially communicated through a pipeline; the method is characterized in that: the low-pressure circulating barrel is connected to a circulating pump, the circulating pump is connected to a gas-liquid mixer, the gas-liquid mixer is connected to an evaporator, the evaporator is connected to the low-pressure circulating barrel, and an air inlet port of the gas-liquid mixer is connected with a second reversing valve.

2. A system for hot defrosting according to claim 1 characterized in that: the first reversing valve is a four-way reversing valve.

3. A system for hot defrosting according to claim 1 characterized in that: the second reversing valve is a three-way reversing valve.

4. A system for hot defrosting according to claim 1 characterized in that: an overflow valve and an electronic expansion valve are arranged in parallel on a pipeline between the condenser and the liquid storage device.

5. A system for hot defrosting according to claim 1 characterized in that: an electromagnetic valve is arranged between the liquid storage device and the low-pressure circulating barrel.

6. A system for hot defrosting according to claim 1 characterized in that: the evaporator is a ceiling fan.

7. A system for hot defrosting according to claim 1 characterized in that: the evaporator is a heat exchange calandria.

8. A system for hot defrosting according to claim 1 characterized in that: the gas-liquid mixer includes a liquid refrigerant inlet, a gas refrigerant inlet, and a gas-liquid outlet.

9. A system for thermal defrosting according to any one of claims 1 to 8 characterized in that: the condenser is a flash evaporation condenser and comprises a shell, a negative pressure fan and a heat exchange unit, wherein the negative pressure fan is arranged at the top of the shell and used for forming negative pressure in the shell; the heat exchange units are arranged in the shell in a stacked mode and comprise water atomizers, multiple rows of coil pipes for circulating refrigerants and fins for fixing the multiple rows of coil pipes, the multiple rows of coil pipes and the fins are fixed through a fixing frame, and the refrigerants flow in from an inlet end and are discharged from an outlet end; multiple rows of coil pipes of the multiple heat exchange units are connected in series or in parallel; the water atomizer is connected with a water source and is used for atomizing water.