KR20200126589A - Cooling System with Self-Controlling of condensing Temperature - Google Patents

Abstract

The present invention calculates the condensation pressure that can be kept at the lowest according to the outside temperature around the condenser, and controls the condensation pressure control means by changing the target condensation pressure through this, thereby maintaining the condensation temperature of the refrigeration system at the lowest possible temperature. It relates to a refrigeration system capable of autonomous control of condensation temperature, which improves the efficiency of the compressor and increases the capacity of the system while reducing
A compressor (10) for adiabatic compression of the refrigerant into a high-temperature, high-pressure gas; A condenser (20) for liquefying the compressed refrigerant by radiating heat through heat exchange with ambient air under a certain pressure; An expansion valve 30 for lowering the pressure by adiabatic expansion of the high temperature and high pressure liquid refrigerant using the throttling action; In a refrigeration system comprising an evaporator 40 that absorbs heat from the surroundings by evaporating the low-pressure liquid refrigerant by endothermic heat exchange with the surrounding air, wherein the refrigerant high pressure senses the pressure of the refrigerant discharged from the evaporator 40 A sensor 51; An outside temperature sensor 52 provided on one side of the condenser 20 to sense the temperature of the outside air; A condensation temperature controller 50 to which the refrigerant high pressure sensor 51 and the outside temperature sensor 52 are connected to set a target condensation temperature according to the high pressure and outside temperature of the refrigerant to control the condensation temperature of the condenser 20; It characterized in that it comprises a; condensing pressure control means 55 for adjusting the condenser 20 or the outlet temperature of the refrigerant so that the condensing pressure is changed in response to the set target condensation temperature.

Description

Refrigeration system with self-controlling of condensing temperature {Cooling System with Self-Controlling of condensing Temperature}

The present invention relates to a refrigeration system capable of autonomously controlling the condensation temperature, and more particularly, to control the condensation pressure control means by calculating the lowest condensation pressure that can be maintained according to the outdoor temperature around the condenser and changing the target condensation pressure through it. The present invention relates to a refrigeration system capable of autonomous control of condensation temperature, thereby improving the efficiency of a compressor and increasing the capacity of a system while reducing power consumption by maintaining the condensation temperature of the refrigeration system at the lowest possible temperature.

In general, a refrigeration system used for air conditioners is an air conditioning device used to properly maintain the indoor temperature through a cooling cycle using the phase change of the refrigerant through temperature and pressure changes. It is widely used throughout.

As shown in FIG. 1, such a conventional refrigeration system includes a compressor for adiabatic compression of a refrigerant into a high-temperature, high-pressure gas, a condenser for liquefying the compressed refrigerant through heat exchange with ambient air under a certain pressure, and a throttling action. An expansion valve that reduces pressure by adiabatic expansion of a high-temperature and high-pressure liquid refrigerant and an evaporator that absorbs heat from the surrounding by evaporating the low-pressure liquid refrigerant through endothermic heat exchange with the surrounding air. Since the condenser is condensed and liquefied while releasing heat from the refrigerant, the performance of the condenser affects the performance of the entire refrigeration system.

On the other hand, since the air-cooled condenser is installed in a form exposed to the outside, it is affected by the temperature of the outside air. That is, when the outside air temperature increases, the condensation temperature increases, so that the capacity of the condenser decreases, and when the outside air temperature decreases, the condensation temperature decreases, thereby improving the capacity of the condenser. According to a related study, it is known that the efficiency of the refrigeration system increases by approximately 2-3% each time the condensation temperature is lowered by 1°C in an air-cooled condenser. Accordingly, the lower the condensation temperature is, the more advantageous it is, but if the condensation temperature is too low, the pressure difference in the expansion valve decreases, resulting in a decrease in the expansion capacity, thereby reducing the efficiency of the refrigeration system. Therefore, it is necessary to adjust to maintain an appropriate condensing pressure according to the outside temperature.

However, the outside temperature is not always kept constant, and changes according to the season or time. In particular, in Korea, there are regions where the temperature difference between summer and winter is more than 50℃ due to the large annual temperature difference, and even during a day, the temperature difference between the outside air is 5℃ or more. This annual or hourly temperature difference acts as a factor that greatly affects the performance of the condenser.

In general, as a method of controlling the condensation temperature in a refrigeration system, a method of controlling the condensation pressure through the condensing pressure control means according to the pressure difference between the set high pressure and the actual high pressure after setting the high pressure value of the refrigeration system in advance is widely used. .

However, the condensation temperature control method described above has the disadvantage that the condensation temperature cannot be adjusted by actively changing the condensing pressure by reflecting the outside temperature that fluctuates hourly or seasonally because the condensation temperature is controlled based on the deviation from the preset high pressure value. have.

Meanwhile, as a result of researching the prior art related to the present invention, the following patent documents were searched.

Patent Document 1 provides a water-cooled condenser that performs heat exchange between fluids while water flows through another flow path adjacent to the refrigerant pipe on a refrigerant pipe positioned between a compressor and an air-cooled condenser, and in the water flow path of the water-cooled condenser The inlet pipe and the outlet pipe are connected so that water is automatically supplied and discharged in the direction opposite to the flow direction of the refrigerant, and water supply can be automatically opened and closed according to the outside temperature, refrigerant pressure, and condensation load on the inlet side of the inlet pipe. Consisting of installing an automatic quantity control valve, or installing an evaporative condenser between the compressor and the air-cooled condenser, but placing the evaporative condenser on the air outlet side of the air-cooled condenser so that moisture is evaporated by the air forced in by the condenser fan. While condensing the refrigerant through the latent heat of evaporation, it can be operated selectively according to changes in outside temperature and refrigerant pressure or condensation load, thereby improving condensation efficiency and coping with rapid outside temperature changes, and reducing power consumption. In addition, it discloses a condensation system of a refrigerator that enables a compact condenser to be implemented.

Patent Document 2 allows the capacity of the refrigeration system to be adjusted by controlling the initial expansion pressure in a cryogenic refrigeration system to which a constant-speed compressor is applied to adjust the amount of refrigerant in the secondary and tertiary condensed refrigerants. A cryogenic refrigeration system capable of capacity control by medium pressure control is disclosed, so that the amount and expansion pressure are linearly controlled to control the evaporation amount of the secondary refrigerant, so that a constant operation can be performed without interruption of the refrigerator.

Patent Document 1: KR10-2003-0087822 A Patent Document 2: KR10-1820683 B1

The present invention was conceived to solve the problems of the prior art, and the condensation pressure that can be kept at the lowest according to the outside air temperature around the condenser is calculated and the target condensation pressure is changed through this to control the condensation pressure control means. The purpose of this is to provide a refrigeration system capable of autonomous control of condensation temperature so as to improve the efficiency of the compressor and increase the capacity of the system while reducing power consumption by maintaining the condensation temperature of the system at the lowest possible temperature.

A refrigeration system capable of autonomously controlling a condensation temperature of the present invention for achieving the above object includes: a compressor for adiabatic compression of a refrigerant into a high temperature and high pressure gas; A condenser for liquefying the compressed refrigerant by radiating heat through heat exchange with ambient air under a predetermined pressure; An expansion valve for reducing a pressure by adiabatic expansion of a high-temperature and high-pressure liquid refrigerant using a throttling action; A refrigeration system comprising: an evaporator for absorbing heat from the surroundings by evaporating the liquid refrigerant of low pressure by heat exchange with the surrounding air by heat exchange, comprising: a refrigerant high pressure sensor for sensing the pressure of the refrigerant discharged from the evaporator; An outside temperature sensor provided on one side of the condenser to sense a temperature of outside air; A condensation temperature controller connected to the refrigerant high pressure sensor and the outside temperature sensor to set a target condensation temperature according to the high pressure and outside temperature of the refrigerant to control the condensation temperature of the condenser; It characterized in that it further comprises a; condensing pressure control means for adjusting the condenser or refrigerant outlet temperature so that the condensation pressure is changed in response to the set target condensation temperature.

In addition, the condensing pressure control means is a method of controlling the number of revolutions of the condenser fan provided in the condenser, a method of controlling the number of operations of the condenser divided into a multistage structure, and opening and closing the cover when a cover is installed that blocks the condenser and the outside. It is characterized in that the condensing pressure of the condenser is controlled using any one of the methods.

In addition, the condensing pressure control means controls the condensing pressure of the condenser by injecting a low temperature liquid or gaseous refrigerant to the discharge side of the compressor to lower the refrigerant discharge temperature of the compressor.

In addition, the condensation temperature controller is characterized in that it calculates the initial target condensation temperature by using the type of refrigerant and the control deviation of the condensation pressure as input values.

In addition, a compression capacity control means for controlling the capacity of the compressor, an opening degree control means for automatically controlling the superheat degree of the expansion valve, an air volume control means of the evaporator, and any one of a heat transfer area control means of the evaporator. It is characterized by that.

The refrigeration system capable of autonomously controlling the condensation temperature of the present invention calculates the condensation pressure that can be kept at the lowest according to the high pressure of the refrigerant discharged from the compressor and the outside air temperature around the condenser, and changes the target condensation pressure through this to control the condensation pressure. Since the condensation pressure control means allows the condensation temperature of the refrigeration system to be maintained at the lowest possible temperature, power consumption for driving the compressor is reduced, the efficiency of the compressor is improved, and the capacity of the system is increased.

In addition, since the condensing pressure and condensing temperature are in a proportional relationship, when the outside temperature is low, the compression ratio is lowered by controlling the condenser components so that the condensing pressure is lowered, thereby reducing the load and power consumption of the compressor, and improving the efficiency. .

1 is a block diagram schematically showing a general refrigeration system.
2 is a schematic diagram showing a refrigeration system capable of autonomous control of condensation temperature according to the present invention.
Figure 3 is a reference diagram for explaining the control method of the condensing pressure control means according to the present invention.

Hereinafter, a refrigeration system capable of autonomous condensation temperature control of the present invention will be described with reference to the accompanying drawings.

For explaining a preferred embodiment of the present invention, FIG. 2 is a schematic diagram of a refrigeration system capable of autonomously controlling condensation temperature according to the present invention, and FIG. 3 is a diagram illustrating a control method of a condensation pressure adjusting means according to the present invention. This is a reference diagram for

A refrigeration system capable of autonomously controlling a condensation temperature according to the present invention includes a compressor 10 for adiabatic compression of a refrigerant into a gas having a high temperature and high pressure, as shown in FIGS. 2 and 3; A condenser 20 for liquefying the compressed refrigerant by radiating heat through heat exchange with ambient air under a certain pressure; An expansion valve 30 for lowering the pressure by adiabatic expansion of the high temperature and high pressure liquid refrigerant using a throttling action; An evaporator 40 for absorbing heat from the surrounding by evaporating the low-pressure liquid refrigerant through endothermic heat exchange with the surrounding air; A refrigerant high pressure sensor 51 for sensing the pressure of the refrigerant discharged from the evaporator 40; An outside temperature sensor 52 provided on one side of the condenser 20 to sense the temperature of the outside air; A condensation temperature controller 50 to which the refrigerant high pressure sensor 51 and the outside temperature sensor 52 are connected to set a target condensation temperature according to the high pressure and outside temperature of the refrigerant to control the condensation temperature of the condenser 20; Condensing pressure control means 55 for adjusting the condenser 20 or the outlet temperature of the refrigerant so that the condensation pressure is changed in response to the set target condensation temperature.

At this time, the condensing pressure adjusting means 55 may control the condensing pressure by controlling the devices constituting the condenser 20, as shown in FIG. 3. Specifically, when controlling the number of rotations of the condenser fan provided in the condenser 20, controlling the number of operations of the condenser 20 divided into a multistage structure, or when a cover blocking the condenser 20 and the outside is installed, the cover is removed. The condensation pressure of the condenser 20 is controlled through a method such as opening and closing. In addition, the condensing pressure control means 55 may adjust the condensation pressure of the condenser 20 in a manner that injects a low-temperature liquid refrigerant or gaseous refrigerant to the discharge side of the compressor 10 to lower the refrigerant discharge temperature of the compressor 10. have.

In addition, the condensation temperature controller 50 calculates the initial target condensation temperature by using the type of refrigerant and the control deviation of the condensation pressure as input values. That is, the initial target condensation temperature is calculated through the control deviation of the type of refrigerant and the condensation pressure to determine the initial condensing pressure, and the high pressure of the refrigerant discharged from the compressor 10 in the refrigeration system operated according to this initial condensing pressure. It is to recalculate the target condensation temperature by sensing each and outside air temperature.

On the other hand, the performance of the compressor is improved according to the condensation temperature control, thereby affecting the balance between the compressor and the evaporator, so that the evaporator TD, which means the difference between the evaporation temperature of the refrigerant in the evaporator 40 and the temperature inside the chamber, may be changed. . That is, as the performance of the compressor improves, the capacity of the evaporator decreases compared to the performance of the compressor, and the evaporator TD increases. As described above, when the evaporator TD increases, the amount of landing of the evaporator increases and the relative humidity of the air decreases. Therefore, measures such as reducing the capacity of the compressor are required. Therefore, the capacity of the compressor 10 is reduced by using the compression capacity control means for controlling the capacity of the compressor 10, or the degree of superheat is reduced by using the opening degree control means for automatically controlling the superheat degree of the expansion valve 30. It is desirable to adjust. In addition, the air volume of the evaporator 40 may be adjusted using the air volume control means, or the heat transfer area of the evaporator 40 may be increased by using the heat transfer area control means.

Although described and illustrated in connection with the embodiments for illustrating the technical idea of the present invention, the present invention is not limited to the configuration and operation as described above, and the scope of the technical idea described in the description and claims of the invention It will be appreciated by those skilled in the art that many changes and modifications may be made to the present invention without departing. Accordingly, all such appropriate changes and modifications and equivalents should be considered to be within the scope of the present invention.

10...compressor
20... condenser
30... expansion valve
40... evaporator
50...condensing temperature controller
51...Refrigerant high pressure sensor
52...Outdoor temperature sensor
55...Condensing pressure control means

Claims (5)

A compressor (10) for adiabatic compression of the refrigerant into a high-temperature, high-pressure gas;
A condenser (20) for liquefying the compressed refrigerant by radiating heat through heat exchange with ambient air under a certain pressure;
An expansion valve 30 for lowering the pressure by adiabatic expansion of the high temperature and high pressure liquid refrigerant using the throttling action;
In a refrigeration system comprising: an evaporator 40 for absorbing heat from the surroundings by evaporating the liquid refrigerant of low pressure through endothermic heat exchange with the surrounding air,
A refrigerant high pressure sensor 51 for sensing the pressure of the refrigerant discharged from the evaporator 40;
An outside temperature sensor 52 provided on one side of the condenser 20 to sense the temperature of the outside air;
A condensation temperature controller 50 to which the refrigerant high pressure sensor 51 and the outside temperature sensor 52 are connected to set a target condensation temperature according to the high pressure and outside temperature of the refrigerant to control the condensation temperature of the condenser 20;
A refrigeration system capable of autonomously controlling condensation temperature, characterized in that it further comprises a condenser (20) or condensation pressure control means (55) for adjusting the outlet temperature of the refrigerant to change the condensation pressure in response to the set target condensation temperature. The method according to claim 1,
Condensation pressure control means 55,
A method of controlling the number of revolutions of the condenser fan provided in the condenser 20,
A method of controlling the number of operations of the condenser 20 divided into a multistage structure,
A method of opening and closing the cover when a cover blocking the condenser 20 and the outside is installed
A refrigeration system capable of autonomous control of condensation temperature, characterized in that the condensing pressure of the condenser 20 is controlled using any one of the methods. The method according to claim 1,
Condensation pressure control means 55,
Autonomous control of condensation temperature is possible, characterized in that the condensation pressure of the condenser 20 is controlled in a manner that lowers the refrigerant discharge temperature of the compressor 10 by injecting a low temperature liquid or gaseous refrigerant to the discharge side of the compressor 10. Refrigeration system. The method according to claim 1,
Condensation temperature controller 50,
A refrigeration system capable of autonomous control of condensation temperature, characterized in that the initial target condensation temperature is calculated by using the type of refrigerant and the control deviation of the condensation pressure as input values. The method according to any one of claims 1 to 4,
Compression capacity control means for controlling the capacity of the compressor 10,
Opening degree control means for automatically controlling the superheat degree of the expansion valve 30,
Air volume control means of the evaporator 40 and
Control means for heat transfer area of evaporator 40
Refrigeration system capable of autonomous control of condensation temperature, characterized in that it further comprises any one of.

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