KR20120022203A - Defrosting system using air cooling refrigerant evaporator and condenser - Google Patents

Abstract

Defrosting system using an air-cooled refrigerant evaporative condenser according to the present invention, the compressor for compressing the refrigerant to a gas state of high temperature and high pressure; A condenser for performing heat exchange between the refrigerant introduced from the compressor and an external heat source; An expansion valve for adiabatic expansion of the liquid refrigerant introduced from the condenser and converting the liquid refrigerant into a refrigerant in a mixed state of a liquid phase and a gaseous phase at low temperature and low pressure; And an evaporator for converting the low temperature low pressure refrigerant introduced from the expansion valve into a low pressure gas state by exchanging heat with an external heat source and introducing the same into the compressor. The condenser includes two heat exchangers arranged in parallel to provide one cooling. An air-cooled evaporative condenser arranged to perform heat exchange with an external air heat source by a fan, wherein the refrigerant flowing into the evaporator from the compressor and passing through the air-cooled evaporative condenser flows into the evaporator; A first solenoid valve and a first expansion valve are sequentially disposed in one of the refrigerant passages from an upstream side to a downstream side in the flow direction of the refrigerant, and a second solenoid valve is disposed in the remaining refrigerant passages. The refrigerant passage through which the refrigerant discharged from the evaporator flows includes two refrigerant passages, each of which is divided into one refrigerant passage. The medium flow passage has a third solenoid valve and is connected to the inlet side of the compressor, and the remaining refrigerant flow passage is connected to the air-cooled evaporative condenser through a fourth solenoid valve and a second expansion valve, and through the second expansion valve. The refrigerant introduced into the air-cooled evaporative condenser is introduced into the compressor through a refrigerant passage having a fifth solenoid valve.

Description

Defrosting system using air cooling refrigerant evaporator and condenser

The present invention relates to a refrigeration cycle apparatus.

Recently, due to the rapid rise in energy prices, energy-saving technologies in the field of cold heat have been rapidly developed, and among them, various energy-saving systems are being developed for defrosting systems.

Generally, when air is cooled to less than saturated air, moisture in the air is removed. In the refrigeration cycle it is dehumidified in the form of water above 0 ° C and in the form of frost below 0 ° C with respect to the defrost of the evaporator. If the temperature is above 0 ℃, dehumidification is in the form of water droplets, but cooling performance is not deteriorated. In the form of frost, dew condensation occurs in the cooling pipe, which becomes a thermal resistance, which lowers the heat transfer performance.

Although there are many defrosting methods, typical natural defrosting (stopping operation) is a method of defrosting with air in a refrigerator up to about 2 ° C, and electric heater defrosting is a method of defrosting with an electric heater. Used. However, most of them use electric heater defrost or water spray defrost.

There is a problem in that required energy is excessively consumed in the defrosting system of the refrigeration cycle. In addition, since the energy used for the defrost is wasted energy, it is necessary to complete the defrost in the shortest possible time, and it is necessary to suppress the temperature rise in the warehouse due to the defrost. As such, in the field of defrosting systems in refrigeration cycles, there is an urgent need to develop a technology for improving cooling performance and saving energy by removing frost from an evaporator in a short time.

SUMMARY OF THE INVENTION An object of the present invention is to provide a defrosting system which has a simple structure and remarkably improved defrosting efficiency by improving the defrosting system of a refrigeration cycle.

In order to achieve the above object, a defrosting system of a refrigeration cycle according to the present invention, the compressor for compressing the refrigerant to a gas state of high temperature and high pressure;

A condenser for performing heat exchange between the refrigerant introduced from the compressor and an external heat source;

An expansion valve for adiabatic expansion of the liquid refrigerant introduced from the condenser and converting the liquid refrigerant into a refrigerant in a mixed state of a liquid phase and a gaseous phase at low temperature and low pressure; And

In the refrigeration system comprising a; evaporator for converting the low-temperature low-pressure refrigerant introduced from the expansion valve with an external heat source to convert into a low-pressure gas state to enter the compressor

The condenser comprises an air-cooled evaporative condenser arranged so that two heat exchangers are arranged in parallel so that heat exchange with an external air heat source is performed by one cooling fan.

Refrigerant flow path into which the refrigerant flowing from the compressor and passing through the air-cooled evaporative condenser flows into the evaporator includes two refrigerant flow paths, one of which flows from the upstream side to the downstream side in the flow direction of the refrigerant flow path. The first solenoid valve and the first expansion valve are sequentially disposed, and the second solenoid valve is disposed in the remaining refrigerant flow path.

The refrigerant passage through which the refrigerant discharged from the evaporator flows includes two refrigerant passages, one of which has a third solenoid valve and is connected to the inlet side of the compressor, and the other refrigerant passage is the fourth refrigerant passage. It is connected to the air-cooled evaporative condenser through the solenoid valve and the second expansion valve, the refrigerant flowing into the air-cooled evaporative condenser through the second expansion valve is introduced into the compressor through a refrigerant flow passage having a fifth solenoid valve It is characterized by.

The air-cooled evaporative condenser is a heat exchanger, and the heat exchange with the low-temperature low-pressure refrigerant flowing into the air-cooled evaporative condenser from the second expansion valve and the high-temperature and high-pressure refrigerant gas discharged from the compressor as well as heat exchange with the external air heat source. desirable.

An oil separator is provided in the refrigerant passage through which the refrigerant discharged from the compressor flows into the air-cooled evaporative condenser.

Preferably, a liquid separator is provided in the refrigerant passage through which the refrigerant discharged from the evaporator flows into the compressor.

The defrosting system according to the present invention does not need a separate heater to remove frost generated in the evaporator, and the heat exchange occurs between the high temperature and high pressure refrigerant gas and the low temperature low pressure refrigerant in the air-cooled evaporative condenser, so that the air-cooled heat exchange and the double heat exchange Since the temperature and pressure of the refrigerant flowing into the compressor can be stably maintained, the defrosting effect and the stable system performance can be realized.

1 is a block diagram of a defrost system of a refrigeration cycle according to the present invention.
2 is a view showing the flow of the refrigerant in the normal operating state of the refrigeration cycle shown in FIG.
3 is a view showing the flow of the refrigerant in the operating state of the defrost system of the refrigeration cycle shown in FIG.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a defrosting system of a refrigeration cycle according to the present invention. 2 is a view showing the flow of the refrigerant in the normal operating state of the refrigeration cycle shown in FIG. 3 is a view showing the flow of the refrigerant in the operating state of the defrost system of the refrigeration cycle shown in FIG.

1 to 3, a defrost system (hereinafter referred to as “defrost system”) using an air cooled refrigerant evaporative condenser according to a preferred embodiment of the present invention is a typical refrigeration cycle system. The defrosting system conventionally does not require the installation of an additional heater for defrosting and is a method of implementing defrosting using a refrigerant.

The defrost system comprises a compressor 10, an air cooled evaporative condenser 20, an expansion valve 30, and an evaporator 40.

The compressor 10 is a device for compressing a refrigerant in a low temperature low pressure gas state into a high temperature high pressure gas state. Since the detailed structure of the compressor 10 is well known, a detailed description thereof will be omitted.

The air-cooled evaporative condenser 20 allows heat exchange between the hot refrigerant gas introduced from the compressor 10 and an external heat source. The air-cooled evaporative condenser 20 increases the temperature of the external heat source by transferring heat from the high temperature and high pressure refrigerant generated from the compressor 10 to the external heat source. The external heat source can be air. The air-cooled evaporative condenser 20 has a structure in which two heat exchangers are arranged in parallel. The air-cooled evaporative condenser 20 is arranged so that two heat exchangers exchange heat with an external air heat source by one cooling fan. In the air-cooled evaporative condenser 20, heat exchange also occurs between the low temperature low pressure refrigerant flowing along the refrigerant passages L7 and L8 described later and the high temperature and high pressure refrigerant discharged from the compressor 10.

The compressor 10 and the air-cooled evaporative condenser 20 are connected by a refrigerant passage L1. An oil separator 50 is provided on the refrigerant passage L1. The oil separator 50 is an apparatus for separating oil components contained in the high temperature and high pressure refrigerant gas discharged to the compressor 10 and recovering the oil components to the compressor 10.

The first expansion valve 30 converts the refrigerant into a low-temperature and low-pressure wetted vapor state, that is, a mixed state of the liquid phase and the gas phase by introducing adiabatic expansion of the liquid refrigerant from the air-cooled evaporative condenser 20. Since the first expansion valve 30 may employ an expansion valve having a known structure, detailed description thereof will be omitted.

The evaporator 40 is a low-temperature gas phase by heat-exchanging the refrigerant introduced from the first expansion valve 30 with an external heat source. The external heat source may be a medium such as water or air.

The air-cooled evaporative condenser 20 and the evaporator 40 are connected by refrigerant passages L2, L3, and L4. The refrigerant passages L2, L3, and L4 are refrigerant passages through which the refrigerant flowing from the compressor 10 and passing through the air-cooled evaporative condenser 20 flows into the evaporator 40. The refrigerant passage L2 is connected to two branched refrigerant passages L3 and L4. The branched refrigerant passages L3 and L4 are combined into one refrigerant passage before being connected to the evaporator 40. One of the two refrigerant passages L3 and L4 is provided with a first solenoid valve 22 and a first expansion valve 30. The first solenoid valve 22 and the first expansion valve 30 are disposed sequentially from the upstream side to the downstream side in the flow direction of the refrigerant. The second solenoid valve 25 is disposed in the remaining refrigerant passage L4 among the two refrigerant passages L3 and L4. The first solenoid valve 22, the second solenoid valve 25, and the third solenoid valve 42, the fourth solenoid valve 45, and the fifth solenoid valve 47, which will be described later, are all adopted by a valve having the same structure. Can be. The upper solenoid valves 22, 25, 52, and 45 may interrupt the flow of refrigerant passing through the valve automatically or manually as necessary.

The refrigerant discharged from the evaporator 40 flows into the compressor 10. The refrigerant passage flowing into the compressor 10 from the evaporator 40 includes two branched refrigerant passages L5 and L6. One refrigerant passage L5 of the two refrigerant passages L5 and L6 is directly connected to an inlet side of the compressor 10. The third solenoid valve 42 is provided on the refrigerant passage L5. The liquid separator 60 is provided on the refrigerant passage L5. The liquid separator 60 separates the liquid refrigerant contained in the refrigerant discharged from the evaporator 40 and sends the refrigerant to the compressor 10. The remaining refrigerant passage L6 of the two refrigerant passages L5 and L6 includes a fourth solenoid valve 45 and a second expansion valve 35 sequentially. The refrigerant discharged from the evaporator 40 may be introduced into the air-cooled evaporative condenser 20 through the fourth solenoid valve 45 and the second expansion valve 35. The refrigerant introduced into the air-cooled evaporative condenser 20 through the second expansion valve 35 exchanges heat with the refrigerant gas of the high temperature and high pressure discharged from the compressor 10. In addition, the air-cooled evaporative condenser 20 is a heat exchange between the refrigerant and the external air heat source. The refrigerant passing through the second expansion valve 35 is introduced into the air-cooled evaporative condenser 20 through the refrigerant passage L7 and is heat-exchanged, and then connected to the refrigerant passage L5 through the refrigerant passage L8. Flows into the compressor (10). The refrigerant passage L8 is provided with a fifth solenoid valve 47.

As described above, the air-cooled evaporative condenser 20 is a heat exchanger, and together with heat exchange with an external air heat source, the refrigerant gas discharged from the compressor 10 and the air-cooled refrigerant from the second expansion valve 35. Heat exchange occurs with the low temperature low pressure refrigerant introduced into the evaporative condenser 20. The heat exchange occurring in the air cooled evaporative condenser 20 is of two types. That is, one type of latent heat generated while the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 10 is changed into a liquid state by heat exchange with an external air heat source. In addition, the low-temperature, low-pressure liquid phase gas-phase mixed refrigerant introduced from the second expansion valve 35 exchanges heat with an air heat source, thereby changing heat into a gaseous refrigerant. In this case, latent heat also occurs in heat exchange. On the other hand, the other type of heat exchange is a phase change between the refrigerant in the high temperature state flowing from the compressor 10 toward the evaporator 40 and the refrigerant in the low temperature state flowing from the second expansion valve 35 to the compressor 10. Heat exchange between sensible heat that does not involve As described above, in the air-cooled evaporative condenser 20, heat exchange efficiency in the form of latent heat and sensible heat is simultaneously generated to improve heat exchange efficiency and to stabilize the temperature and pressure of the refrigerant flowing into the compressor 10. I can keep it.

Hereinafter, the operation of the present invention will be described in detail along the flow of the refrigerant in the air-cooled evaporative condenser 20 in the refrigeration cycle having the defrost system having such a configuration.

First, a normal driving state will be described with reference to FIG. 2. In the normal operating state, no frost occurs in the evaporator 40, so there is no need for defrosting.

In FIG. 2, the second solenoid valve 25 and the fourth solenoid valve 45 are closed. Therefore, the refrigerant is compressed in the compressor 10 and flows to the oil separator 50 along the refrigerant passage L1 in a gas state of high temperature and high pressure. The oil separator 50 separates oil introduced into the refrigerant and recovers the oil to the compressor 10. The refrigerant passing through the oil separator 50 is introduced into the air-cooled evaporative condenser 20 along the refrigerant passage L1. The air-cooled evaporative condenser 20 performs heat exchange with an external air heat source. The refrigerant discharged from the air-cooled evaporative condenser 20 is in a liquid low temperature state. The refrigerant discharged from the air-cooled evaporative condenser 20 is introduced into the first expansion valve 30 through the first solenoid valve 22 along the refrigerant passages L2 and L3. In the first expansion valve 30, the refrigerant is adiabaticly expanded and converted into a mixed state of a low temperature liquid phase and a gaseous phase. The refrigerant discharged from the first expansion valve 30 flows into the evaporator 40. In the evaporator 40, the refrigerant is supplied with heat from an external heat source to change to a low temperature gas state. The refrigerant discharged from the evaporator 40 is introduced into the compressor 10 through the liquid separator 60 through the third solenoid valve 42 along the refrigerant flow path L5. It is a normal refrigeration cycle that this process is performed repeatedly.

However, as repeated refrigeration cycles are performed or when the temperature outside the evaporator is low, frost occurs on the surface of the evaporator 40. In such a case, the defrost system must be activated. Hereinafter, the flow of the refrigerant in the state in which the defrost system is operated will be described.

3 is a view showing the flow of the refrigerant in the defrost system is operating.

In the configuration diagram shown in FIG. 3, the first solenoid valve 22 and the third solenoid valve 42 are closed. The second solenoid valve 25, the fourth solenoid valve 45, and the fifth solenoid valve 47, which are the remaining solenoid valves, are open.

Therefore, the refrigerant is compressed in the compressor 10 and flows to the oil separator 50 along the refrigerant passage L1 in a gas state of high temperature and high pressure. The oil separator 50 separates oil introduced into the refrigerant and recovers the oil to the compressor 10. The refrigerant passing through the oil separator 50 is introduced into the air-cooled evaporative condenser 20 along the refrigerant passage L1. The air-cooled evaporative condenser 20 performs heat exchange with an external air heat source. The refrigerant discharged from the air-cooled evaporative condenser 20 is in a liquid low temperature state. The refrigerant discharged from the air-cooled evaporative condenser 20 is introduced into the evaporator 40 through the second solenoid valve 25 along the refrigerant passages L2 and L4. In the evaporator 40, the coolant is transferred to the outside to reduce the temperature of the coolant. In other words, the evaporator 40 acts similar to the condenser in the cycle in which the defrost system is operated. Therefore, the high temperature refrigerant introduced into the evaporator 40 is lowered in temperature while performing a defrosting operation by transferring heat to frost generated outside the evaporator 40. In the cycle in which the defrosting system operates as described above, after the heat exchange is performed in the air-cooled evaporative condenser 20, the relatively high-temperature refrigerant is bypassed so as not to pass through the first expansion valve 30 to be introduced into the evaporator 40. Effective defrosting can be performed.

After the defrosting operation is performed in the evaporator 40, the refrigerant having a lower temperature is introduced into the second expansion valve 35 through the fourth solenoid valve 45 along the refrigerant passage L6. While passing through the second expansion valve 35, the refrigerant is adiabaticly expanded to change into a mixed state of the liquid phase and the gaseous phase. The refrigerant passing through the second expansion valve 35 is introduced into the air-cooled evaporative condenser 20 through the refrigerant passage L7. In the air-cooled evaporative condenser 20, the refrigerant introduced from the second expansion valve 35 is changed into a gas state while undergoing heat exchange with the refrigerant gas of high temperature and high pressure introduced from the compressor 10. In this process, the refrigerant introduced from the second expansion valve 35 may receive heat from an external air heat source. The refrigerant flowing from the air-cooled evaporating compressor 10 toward the compressor 10 is connected to the refrigerant passage L5 connected to the compressor 10 through the fifth solenoid valve 47 along the refrigerant passage L8. Flow. Therefore, since the latent heat and sensible heat may contribute to the refrigerant flowing from the second expansion valve 35 to the compressor 10, the temperature and pressure of the refrigerant gas flowing into the compressor 10 may be stably maintained. It works. This process is performed repeatedly, a refrigeration cycle with the defrost system in operation.

As described above, the refrigerating cycle according to the present invention has an effect of effectively defrosting by the action of the air-cooled evaporative condenser 20 as well as maintaining a constant temperature and pressure of the refrigerant flowing into the compressor 10. .

As described above, the defrosting system according to the present invention does not need a separate heater to remove frost generated in the evaporator. In the air-cooled evaporative condenser, the high-temperature high-pressure refrigerant gas and the low-temperature low-pressure refrigerant heat exchange occurs, thereby overlapping the air-cooled heat exchange. Since the heat exchange is carried out, it is possible to stably maintain the temperature and pressure of the refrigerant flowing into the compressor, thereby achieving an excellent defrosting effect and stable system performance.

That is, the defrosting system according to the present invention can use the latent heat of condensation, thereby shortening the defrosting time and saving power consumption. The defrost system sends a high temperature refrigerant gas (60 ℃ ~ 80 ℃) or a high temperature liquid refrigerant (40 ℃ ~ 50 ℃) to the evaporator using the sensible heat and latent heat to liquefy the high pressure mixed refrigerant gas in the refrigerant evaporative condenser and low pressure mixed refrigerant After degassing and expanding the gas, it is exchanged with air to maintain high pressure gas temperature and pressure so that defrost energy is consumed at 50 ~ 60% of the energy required for cooling, saving 40% ~ 50% of defrost energy. The defrosting system can ensure a sufficient amount of refrigerant circulation and is very stable.

While the present invention has been described with reference to the preferred embodiments, it is to be understood that the invention is not to be limited by the example, and various changes and modifications may be made without departing from the spirit and scope of the invention.

10: compressor 20: condenser combined with air cooling evaporation
22: first solenoid valve 25: second solenoid valve
30: first expansion valve 35: second expansion valve
40: evaporator 42: third solenoid valve
45: fourth solenoid valve 47: fifth solenoid valve
50: oil separator 60: liquid separator
L1 ~ L8: refrigerant flow path

Claims (3)

A compressor for compressing the refrigerant into a gaseous state of high temperature and high pressure;
A condenser for performing heat exchange between the refrigerant introduced from the compressor and an external heat source;
An expansion valve for adiabatic expansion of the liquid refrigerant introduced from the condenser and converting the liquid refrigerant into a refrigerant in a mixed state of a liquid phase and a gaseous phase at low temperature and low pressure; And
In the refrigeration system comprising a; evaporator for converting the low-temperature low-pressure refrigerant introduced from the expansion valve with an external heat source to convert into a low-pressure gas state to enter the compressor
The condenser comprises an air-cooled evaporative condenser arranged so that two heat exchangers are arranged in parallel so that heat exchange with an external air heat source is performed by one cooling fan.
Refrigerant flow path into which the refrigerant flowing from the compressor and passing through the air-cooled evaporative condenser flows into the evaporator includes two refrigerant flow paths, one of which flows from the upstream side to the downstream side in the flow direction of the refrigerant flow path. The first solenoid valve and the first expansion valve are sequentially disposed, and the second solenoid valve is disposed in the remaining refrigerant flow path.
The refrigerant passage through which the refrigerant discharged from the evaporator flows includes two refrigerant passages, one of which has a third solenoid valve and is connected to the inlet side of the compressor, and the other refrigerant passage is the fourth refrigerant passage. It is connected to the air-cooled evaporative condenser through the solenoid valve and the second expansion valve, and the refrigerant introduced into the air-cooled evaporative condenser through the second expansion valve is introduced into the compressor through a refrigerant passage provided with a fifth solenoid valve. A defrost system using an air cooled refrigerant evaporative condenser. The method of claim 1,
The air-cooled evaporative condenser is a heat exchanger that exchanges heat with an external air heat source, and a high-temperature high-pressure refrigerant gas discharged from the compressor and a low-temperature low-pressure refrigerant introduced into the air-cooled evaporative condenser from the second expansion valve. A defrost system using an air cooled refrigerant evaporative condenser. The method according to claim 1 or 2,
An oil separator is provided in the refrigerant passage through which the refrigerant discharged from the compressor flows into the air-cooled evaporative condenser.
A defrost system using an air-cooled evaporative condenser, characterized in that a liquid separator is provided in the refrigerant passage through which the refrigerant discharged from the evaporator flows into the compressor.

Images