KR20090003813A - Cryogenic composite refrigeration unit and its control method - Google Patents

Abstract

The present invention relates to an ultra-low temperature complex refrigeration system and a control method by combining the direct cooling method with the indirect cooling method to shorten the return time of the set temperature in the freezer and reduce the power consumption. According to an embodiment, the internal warehouse 100 In the refrigeration system of), the first compressor (12), the first condenser (14), the first expansion valve (16), the first evaporator (18) disposed in the freezing chamber (102) of the freezer (100) Direct cooling unit 10 provided; Cooling endothermic and cooled in the second compressor 22, the second condenser 24, the second expansion valve 26, the second evaporator 28 and the second evaporator 28 disposed in the freezer compartment 102 An indirect cooling unit (20) having a cold air fan (29) for delivering air to the freezing compartment; A temperature sensor 202 installed in the freezing compartment 102; It characterized in that it comprises a control unit 200 for controlling the operation of the first compressor 12, the second compressor 22 and the solenoid valve 15 according to the temperature change detected by the temperature sensor 202.

Description

Cryogenic composite refrigeration system and its control method

The following drawings, which are attached in this specification, illustrate preferred embodiments of the present invention, and together with the detailed description of the present invention, serve to further understand the technical spirit of the present invention. It should not be construed as limited to.

1 is a schematic configuration diagram of a cryogenic composite refrigeration system according to the present invention.

Figure 2 is a flow chart of the operation of the first and second compressors applied to the cryogenic composite refrigeration system according to the present invention.

Figure 3 is a flow chart of the operation of the solenoid valve applied to the cryogenic composite refrigeration system according to the present invention.

Figure 4 is an operation diagram according to the temperature control of the first and second compressors applied to the cryogenic composite refrigeration system according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: Direct Cooling Unit

15: Expansion valve

12,22: first and second compressor

14,24: 1st, 2nd condenser

16, 26: 1st, 2nd expansion valve

18,28: 1st, 2nd evaporator

20: indirect cooling unit

200: control unit

202: temperature sensor

The present invention relates to an ultra low temperature complex refrigeration system and a control method thereof, and more particularly, to an ultra low temperature complex refrigeration system and control method in which a direct cooling method is combined with an indirect cooling method to shorten the return time of a set temperature in a freezer warehouse and reduce power consumption. It is about.

In general, the temperature of the freezer warehouse is rapidly increased because the door must be opened during the entry and export time of the display goods. In particular, in the case of cryogenic freezers that implement freezers below minus 50 degrees, changes in the cooling temperature will degrade the quality of the display goods.

Therefore, in the case of freezing and storing the fish sashimi such as tuna freshness is important, even if the freezing temperature rises it should be dropped to the cooling temperature set in a short time to prevent changes in the meat quality of the frozen product.

Conventionally, a refrigeration system for implementing a cryogenic freezing warehouse used either a direct cooling method or an indirect cooling method. Here, the direct cooling method is a method of cooling the freezer compartment by using an endotherm of the evaporator, and the indirect cooling method is a method of cooling by cooling the cooled cold air.

However, when using these direct and indirect cooling methods individually, there are the following problems.

In the case of the direct cooling method, there is a problem that it takes a long time to return to the set temperature, and in the case of the indirect cooling method, there is a problem of causing dry phenomenon of the display goods.

For this reason, when using the direct and indirect cooling method individually, the freezing temperature is increased due to the inflow of outside air at the time of import and export of goods in the freezer warehouse, the freshness of the display goods is reduced and the quality of meat cannot be prevented.

Therefore, the present invention was created in view of the above-mentioned circumstances, and combined with the direct cooling method and the indirect cooling method to shorten the return time of the set temperature in the freezer warehouse so that there is no change in freshness or meat quality of the display goods. It is an object of the present invention to provide a cryogenic complex refrigeration system and a control method thereof, which can greatly reduce power consumption.

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

1 is a schematic view of implementing a refrigeration system of the inner warehouse 100 according to the present invention.

As illustrated in FIG. 1, the freezer warehouse 100 includes a direct cooling unit 10 and an indirect cooling unit 20.

The direct cooling unit 10 includes a first compressor 12, a first condenser 14, a first expansion valve 16, a first evaporator 18 disposed in the freezing chamber 102 of the freezer warehouse 100 and The solenoid valve 15 is provided between the said 1st condenser 14 and the said 1st expansion valve 16, and opens and closes a refrigerant flow path.

At this time, the first compressor 12, the first condenser 14, the first expansion valve 16, the solenoid valve 15 and the first evaporator 18 are sequentially connected in series.

In order to control the solenoid valve 15, an inlet side of the first compressor 12 is provided with a pressure sensor 11 for measuring a refrigerant pressure.

At this time, the first evaporator 18 is composed of a plurality of unit evaporators 18A, 18B, 18C are interconnected in parallel. In the conceptual diagram, three unit evaporators are configured, but the present invention is not limited to this number and can be increased or decreased.

Therefore, the refrigerant circulating in the cooling pipe of the direct cooling unit 10 flows into the first compressor 12 while simultaneously flowing in parallel rows of unit evaporators 18A, 18B, and 18C branched from the expansion valve 16. Therefore, the first evaporator 18 can implement a fast cycle of the refrigerant to reduce the endothermic resistance.

The indirect cooling unit 20 includes a second compressor 22, a second condenser 24, a second expansion valve 26, a second evaporator 28 disposed in the freezer compartment 102, and the second evaporator ( And a cooling air fan 29 for discharging the cooling air cooled by the endothermic to the freezing compartment 102, and the freezing fan 29 is electrically connected to the control unit 200 and driven and controlled.

Therefore, the cold air fan 29 supplies the cold air cooled by the second evaporator 28 into the freezing compartment 102.

The freezing chamber 102 is provided with a temperature sensor 202 for detecting the cooling temperature in the freezing chamber 102.

The controller 200 controls the first compressor 12, the second compressor 22, and the solenoid valve 15 according to the temperature change detected by the temperature sensor 202 and the pressure detected by the pressure sensor 11. It is to control the operation.

Therefore, the control unit 200 receives the electrical signals detected from the pressure sensor 11 and the temperature sensor 202, and compares them with the set temperature and the set pressure to determine the first compressor 12, the solenoid valve 15, The operation of the two compressors 22 and the blower fan 29 is controlled.

The operation and control method of the cryogenic composite refrigeration system configured as described above will be described with reference to FIGS. 2 and 3.

First, driving temperatures T1 and T2 of the first compressor 12 and the second compressor 22 are set (S10).

Next, the temperature T of the freezing compartment 102 in the freezer warehouse 100 is detected by the temperature sensor 202 (S11).

Subsequently, the controller 200 determines the detected temperature T detected by the temperature sensor 202 with the driving temperatures T1 and T2, respectively, to determine the first and second compressors 12 and 22. Controlling the drive.

At this time, when the first compressor 12 is driven, the refrigerant supplied to the direct cooling unit 10 is condensed in the first condenser 14 and then decompressed through the solenoid valve 15 through the first expansion valve 16. The first evaporator 18 evaporates while absorbing heat from the freezing chamber air. At this time, the pressure sensor 11 detects the refrigerant pressure P at the inlet side flowing into the first compressor 12.

On the other hand, when the second compressor 12 is driven, the refrigerant supplied to the indirect cooling unit 20 is condensed in the second condenser 24, the pressure is reduced through the second expansion valve 16, the second evaporator 28 Endothermic evaporation in the cold air generates cold air, and cold air is blown into the freezing chamber 102 by the blowing fan 29.

At this time, when it is determined that the driving temperature T2 of the second compressor 22 is lower than the detection temperature T (S12), both the first compressor 12 and the second compressor 22 are driven (S13).

This condition occurs when bringing in or taking out the display into the freezer.

If the driving temperature T2 of the second compressor 22 is equal to the detection temperature T or the detection temperature T is smaller than the driving temperature T2 of the second compressor 22, If it is determined that the drive temperature (T1) is greater than (S14), the first compressor 12 is driven and at the same time the second compressor 22 is stopped (S15).

In addition, when it is determined that the driving temperature T1 of the first compressor 12 is equal to the detection temperature T (S16), all of the first and second compressors 12 and 22 are stopped (S17).

On the other hand, the control unit 200 controls the opening and closing of the solenoid valve 15 by determining the detected pressure P detected by the pressure sensor 11 compared with the set pressure PO.

)보다 높을 경우, 전자밸브(15)가 오프(off)되어 닫아지고, 냉매압력(P)이 설정압력(

) 보다 작거나 동일할 경우 온(on)되어 정상적으로 열려진다.That is, as shown in FIG. 3, the refrigerant pressure P detected by the pressure sensor 11 is the set pressure (

Is higher than), the solenoid valve 15 is turned off and closed, and the refrigerant pressure P

If it is less than or equal to), it will be on and open normally.

<Example>

)를 영하60℃로 설정하였다.In the present embodiment, the drive temperature T1 of the first compressor 12 is set to minus 58 degrees Celsius, the drive temperature T2 of the second compressor 22 is set to minus 57 degrees Celsius, and is set in the freezer compartment 102. Temperature(

) Was set at minus 60 ° C.

In this state, when the temperature detected by the temperature sensor 202 rises to minus 57 ° C., the first compressor 12 and the second compressor 22 are driven simultaneously by the drive signals C1 and C2 of the controller 200. Both the first evaporator 18 and the second evaporator 28 are activated (see FIG. 4). At this time, the blowing fan 29 is also operated to blow cold air.

Therefore, the temperature in the freezing chamber 102 is lowered within a short time by using both the direct cooling method and the indirect cooling method.

Then, when the temperature in the freezer compartment 102 reaches minus 58 ℃, the second compressor 22 is stopped. At this time, the blowing fan 29 is also stopped. That is, the indirect cooling system stops.

If only the first compressor 12 is driven until the temperature of the freezer compartment 102 reaches minus 60 ° C.

Then, when the temperature in the freezer compartment 102 reaches minus 60 ℃, the first compressor 12 is also stopped. In other words, if the set temperature (less than 60 ℃) and the actual measured temperature in the freezer compartment 102 is the same, both the direct and indirect cooling system is stopped.

As described above, according to the present invention, it is possible to quickly reach the set temperature by selectively or simultaneously driving the direct and indirect cooling system according to the temperature change in the warehouse freezing chamber 102.

In addition, the drying phenomenon occurs when only cooling by the indirect cooling method, but only the direct cooling system is driven at the desired set temperature, the drying phenomenon is prevented in the present invention, it is possible to reduce the power consumption.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the following by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

As described above, according to the ultra-low temperature complex refrigeration system of the present invention and a control method thereof, by directly or indirectly operating a direct or indirect cooling system according to a temperature change in a warehouse freezer, it is possible to reach a set temperature quickly with energy saving. In addition, the drying phenomenon occurred when cooling only by the indirect cooling method, but the drying phenomenon of the product is prevented because only the direct cooling system is operated at the desired set temperature. In addition, the first evaporator applied to the direct cooling method is installed in a plurality of unit evaporators in parallel to improve the evaporation efficiency.

Claims (8)

In the refrigeration system of the inner warehouse 100, Direct cooling unit (10) having a first compressor (12), a first condenser (14), a first expansion valve (16), and a first evaporator (18) disposed in the freezer compartment (102) of the freezer warehouse (100). )and; Cooling endothermic and cooled in the second compressor 22, the second condenser 24, the second expansion valve 26, the second evaporator 28 and the second evaporator 28 disposed in the freezer compartment 102 An indirect cooling unit (20) having a cold air fan (29) for delivering air to the freezing compartment; A temperature sensor 202 installed in the freezing compartment 102; Ultra low temperature composite, characterized in that it comprises a control unit 200 for controlling the operation of the first compressor 12, the second compressor 22 and the solenoid valve 15 according to the temperature change detected by the temperature sensor 202. Refrigeration system. The method of claim 1, The first evaporator (18) is a cryogenic complex refrigeration system, characterized in that configured by interconnecting a plurality of unit evaporators (18A, 18B, 18C) in parallel. The method of claim 1, The solenoid valve 15 which is installed between the first condenser 14 and the first expansion valve 16 and opens and closes the refrigerant flow passage in accordance with the inlet pressure change of the first compressor 12 is opened. In the method for controlling the refrigeration system of the refrigerated warehouse any one of claims 1 to 3, (a) setting respective drive temperatures T1 and T2 of the first compressor 12 and the second compressor 22; (b) detecting the temperature of the freezing compartment 102 in the freezer with a temperature sensor 202; (c) controlling the driving of the first compressor 12 and the second compressor 22 by comparing the detected temperature T detected by the temperature sensor 202 with the driving temperatures T1 and T2, respectively. Control method of a cryogenic complex refrigeration system, characterized in that configured to include. The method of claim 4, wherein And driving both the first compressor 12 and the second compressor 22 when the driving temperature T2 of the second compressor 22 is lower than the detection temperature T in step (c). Cryogenic composite refrigeration system. The method of claim 4, wherein In step (c), the driving temperature T2 of the second compressor 22 is equal to the detection temperature T or the detection temperature T is smaller than the driving temperature T2 of the second compressor 22 and the first compressor And controlling the second compressor (22) to stop the second compressor (22) when the driving temperature (T1) is greater than (12). The method of claim 4, wherein And stopping both the first and second compressors 12 and 22 when the driving temperature T2 of the first compressor 12 is equal to the detection temperature T in the step (c). How to control the cryogenic composite refrigeration system. The method of claim 4, wherein And controlling the opening and closing control of the solenoid valve (15) by detecting the inlet pressure of the first compressor (12).

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