KR20130086864A - A combined refrigerating and freezing system and a control method the same - Google Patents

Abstract

PURPOSE: A freezing and cooling system is provided to differently set evaporation temperature or pressure of a cooling system. CONSTITUTION: A method for controlling a freezing and cooling system comprises following steps. Whether or not a cooling system is operated is recognized (S11). The cooling system is operated (S12, S13). Third evaporation temperature is set corresponding to the half of the evaporation pressure (S14). Whether or not the cooling system is operated is recognized (S15). The freezing system is operated (S16, S17). A second compressor is turned off when cold air is not supplied to a cooling chamber (S18). A first compressor is selectively turned on and off according to whether the cooling system is operated or not (S19). [Reference numerals] (AA) Start; (BB) End; (S11,S15) Recognize the operation of a cooling system; (S12,S16) Order for the operation of the cooling system is inputted?; (S13) Set and operate the cooling system at an evaporation temperature of T_1; (S14) Set and operate the cooling system at an evaporation temperature of T_3; (S17) Set and operate the cooling system at an evaporation temperature of T_2; (S18) Turn off a second compressor; (S19) Turn off a first compressor selectively

Description

A combined refrigerating and freezing system and a control method the same}

The present invention relates to a refrigeration refrigeration composite system and a control method thereof.

The refrigeration system is for refrigeration of articles and the like in the first predetermined space by the refrigerant flowing through the heat exchange cycle and the heat exchange in the outdoor air space, and the heat exchange between the refrigerant and the first predetermined space. In the refrigeration system, refrigeration of articles or the like is performed in the second predetermined space by heat exchange between the refrigerant flowing in the heat exchange cycle and the outdoor air, and heat exchange between the refrigerant and the second predetermined space.

In detail, the refrigeration system includes a first compressor for compressing a refrigerant, a refrigerated condenser for exchanging heat between the refrigerant and indoor and outdoor air, a refrigerating expansion device for depressurizing the refrigerant, and a refrigeration for evaporating the expanded refrigerant. An evaporator is included.

The refrigeration system includes a second compressor for compressing the refrigerant, a refrigeration condenser for condensing the refrigerant, an expansion device for refrigerating the refrigerant, and an evaporator for evaporating the refrigerant. As such, the refrigeration system and the refrigeration system are driven by a similar refrigerant system.

However, in the related art, the refrigeration system and the refrigeration system are driven separately, so there is a problem in that the manufacturing cost for constructing the system is high. In particular, it has been pointed out that the inefficiency of driving the system with a separate heat exchanger (eg, a condenser) has been pointed out as a problem.

On the other hand, recently, a complex system in which a refrigeration system and a refrigeration system operate in conjunction with each other has been developed. The complex system includes a heat exchanger in which heat exchange is performed between the refrigerant of the refrigeration system and the refrigerant of the refrigeration system. In one example, the heat exchanger can function as a condenser of the refrigeration system.

However, in the case of such a complex system, as shown in FIG. 1, when the refrigeration and refrigeration complex system is operated (S1), the refrigeration system is operated while being set to a specific evaporation temperature (first set temperature) ( S2), the refrigeration system was operated in a state set to a specific evaporation temperature (second set temperature) (S3).

According to such a complex system, even when the refrigeration system or the refrigeration system is stopped, there is a problem that the refrigerant cycle is operated according to the set first and second set temperatures.

In particular, when the refrigeration system is operated and the refrigeration system is stopped, the refrigeration cycle is driven with an unnecessarily low evaporation temperature set even though the refrigeration system only functions to dissipate the condensation heat of the refrigeration system in the heat exchanger. There was a problem that the system efficiency is lowered.

That is, in the conventional refrigeration and refrigeration system, according to the operating state of the refrigeration system or the refrigeration system does not separately control the pressure (especially the evaporation pressure) of the system to generate unnecessary heat exchange action, thereby reducing the heat exchange efficiency there was.

In order to solve this problem, it is an object of the present invention to provide a refrigeration refrigeration complex system that can set the evaporation pressure or evaporation temperature of the refrigeration system differently depending on whether the refrigeration system is operating.

A refrigeration refrigeration combined system according to an embodiment of the present invention, the first compressor for compressing the refrigerant of the refrigeration system for the refrigeration operation of the first set space; A second compressor for compressing the refrigerant of the refrigeration system for the refrigeration operation of the second set space; A condenser arranged to pass the refrigerant compressed by the first compressor; A first evaporator configured to evaporate at least a portion of the refrigerant having passed through the condenser and to supply cold air to the first predetermined space; A heat exchanger for performing heat exchange between the refrigerant passing through the second compressor and the refrigerant passing through the condenser; A second evaporator for evaporating the refrigerant passing through the heat exchanger; A temperature sensing unit sensing at least one of a condensation temperature of the refrigerant passing through the condenser and an evaporation temperature of the refrigerant passing through the second evaporator; And a controller configured to determine a reference pressure passing through the heat exchanger based on the temperature sensing unit when it is recognized that supplying cold air to the first set space is stopped.

According to another aspect of the present invention, a method for controlling a refrigeration refrigeration combined system includes a refrigeration system in which a refrigeration refrigerant is circulated and a refrigeration compressor, a condenser and a first evaporator, and a refrigeration system in which a refrigeration refrigerant is circulated, and a refrigeration compressor and a second evaporator. A method of controlling a refrigeration refrigeration combined system comprising a step of stopping the operation of the refrigeration system to stop the supply of cold air to the refrigerating compartment; Recognizing the condensation pressure of the refrigerant passing through the condenser; Recognizing the evaporation pressure of the refrigerant passing through the second evaporator; And determining, based on the condensation pressure and the evaporation pressure, a reference pressure relating to evaporation of the refrigerant circulating in the refrigeration system.

According to this embodiment of the present invention, since the refrigeration system and the refrigeration system are configured in combination, heat exchange may be performed using a single condenser, and thus the system may be simply configured and the refrigeration and freezing operation may be simultaneously performed.

In addition, since the evaporation pressure or the evaporation temperature of the refrigeration system can be set optimally depending on whether the refrigeration system is operated, there is an effect that the refrigeration refrigeration combined system can be effectively driven.

That is, when refrigeration of the storage compartment is required, the refrigeration system is operated by setting the first evaporation temperature. When refrigeration of the storage compartment is not required, the refrigeration system is operated by setting the third evaporation temperature required for heat dissipation of the refrigeration system. There is an effect that the operating efficiency or heat exchange efficiency of the can be improved.

In addition, since the third evaporation temperature can be easily determined from a relationship table of the pre-stored condensation pressure (high pressure) of the refrigeration system and the evaporation pressure (low pressure) of the refrigeration system, control of the complex system can be made quickly and effectively There is an advantage that it can.

1 is a flow chart showing a control method of a conventional complex system.
2 is a system diagram showing the configuration of a refrigeration refrigeration combined system according to an embodiment of the present invention.
Figure 3 is a block diagram showing the configuration of a refrigeration refrigeration combined system according to an embodiment of the present invention.
Figure 4 is a flow chart showing a control method of the refrigeration refrigeration combined system according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. It is to be understood, however, that the spirit of the invention is not limited to the embodiments shown and that those skilled in the art, upon reading and understanding the spirit of the invention, may easily suggest other embodiments within the scope of the same concept.

2 is a system diagram showing the configuration of a refrigeration refrigeration combined system according to an embodiment of the present invention.

2, the refrigeration refrigeration composite system 10 (hereinafter, "combined system") according to an embodiment of the present invention is a combination of a refrigeration system and a refrigeration system.

In detail, the refrigeration system, the first compressor 20 for compressing the refrigeration refrigerant, the condenser 30 for condensing the refrigerant compressed by the first compressor 20, and blows outside air to the condenser 30 The main fan includes a blower fan 35, a first expansion device 42 for reducing the refrigerant condensed in the condenser 30, and a first evaporator 50 for evaporating the refrigerant passing through the first expansion device 42. do. The cold air generated by the first evaporator 50 may be supplied to the first predetermined space (refrigeration chamber). The first compressor 20 and the first evaporator 50 may be referred to as "refrigeration compressor" and "refrigeration evaporator", respectively.

The refrigeration system includes a first refrigerant pipe 70 (refrigerated refrigerant pipe) guiding the flow of the refrigerant circulating in the refrigeration system. The refrigerant circulates through the first refrigerant pipe 70, the first compressor 20, the condenser 30, the first expansion device 42, and the first evaporator 50.

The refrigeration system includes a second compressor 25 for compressing the refrigerant for cooling, a heat exchanger 80 for condensing the refrigerant compressed by the second compressor 25, and a refrigerant condensed in the heat exchanger 80. The second expansion device 45 for reducing the pressure and the second evaporator 55 for evaporating the refrigerant passed through the second expansion device 45 is included. The cold air generated by the second evaporator 55 may be supplied to the second set space (freezer). The second compressor 25 and the second evaporator 55 may be referred to as "freezing compressor" and "freezing evaporator", respectively.

The first compressor 20 and the second compressor 25 may be an inverter compressor capable of adjusting an operating frequency (compression ratio).

The heat exchanger 80 may be referred to as a "cascade heat exchanger" as a configuration for performing heat exchange between the refrigerant circulating the refrigeration system and the refrigerant circulating the refrigeration system. Some of the refrigerant (first refrigerant) circulating in the refrigeration system and the refrigerant (second refrigerant) circulating in the refrigeration system are introduced into the heat exchanger (80). In addition, the first refrigerant and the second refrigerant may be indirect heat exchange without being mixed in the heat exchanger 80.

The refrigeration system includes a second refrigerant pipe 60 (refrigeration refrigerant pipe) guiding the flow of the refrigerant circulating in the refrigeration system. The refrigerant circulates through the second refrigerant pipe 60 and the second compressor 25, the heat exchanger 80, the second expansion device 45, and the second evaporator 55.

The first refrigerant pipe 70 includes a branch portion 73 to allow at least some of the refrigerant passing through the condenser 30 to be bypassed to the heat exchanger 80. That is, some of the refrigerant passing through the condenser 30 may flow from the branch portion 73 to the first expansion device 42, and the remaining refrigerant may flow to the heat exchanger 80.

The refrigeration system includes a bypass flow passage 83 for guiding the flow of the refrigerant from the branch portion 73 to the heat exchanger 83. The bypass flow path 83 further extends from the outlet side of the heat exchanger 80 to the inlet side of the first compressor 20.

The bypass passage 83 is provided with a third expansion device 85 disposed at the inlet side of the heat exchanger 80 to reduce the refrigerant to be introduced into the heat exchanger 80. As the opening degree of the third expansion device 85 is adjusted, at least some of the refrigerant having passed through the condenser 30 may flow into the bypass flow path 83.

For example, when the third expansion device 85 is closed, all of the refrigerant passing through the condenser 30 may be guided to the first expansion device 42. On the other hand, when the third expansion device 85 is at least partially open, at least some of the refrigerant passing through the condenser 30 may flow into the bypass flow path 83.

The refrigeration system includes a lamination portion 76 in which the first refrigerant pipe 70 and the bypass flow path 83 are laminated. The lamination portion 76 is formed at the inlet side of the first compressor 20.

The refrigerant of the refrigeration system passing through the first evaporator 50 and the refrigerant of the refrigeration system passing through the heat exchanger 80 are laminated at the lamination unit 76, and the laminated refrigerant is the first compressor 20. Flows into.

Hereinafter, the operation of the complex system 10 according to the embodiment of the present invention will be described briefly.

First, when both the refrigerating system and the refrigerating system are operated to supply cold air to a predetermined storage compartment, that is, the refrigerating compartment and the freezing compartment, the refrigerant of the refrigerating system circulates both the first evaporator 50 and the heat exchanger 80.

That is, the refrigerant of the refrigerating system that has passed through the condenser 30 is branched from the branch portion 73 so that some of the refrigerant flows into the first expansion device 42, and the remaining refrigerant passes through the bypass passage 83. It is introduced into the third expansion device 85 via the. At this time, the first expansion device 42 and the third expansion device 85 maintains an open state.

The refrigerant passing through the first expansion device 42 is evaporated in the first evaporator 50 to generate cold air. In addition, the refrigerant passing through the third expansion device 85 exchanges heat with the refrigerant of the refrigeration system in the heat exchanger 80, and condenses the refrigerant of the refrigeration system in this process.

On the other hand, when the refrigerating system is operated to supply cold air to the refrigerating compartment, and the operation of the refrigerating system is stopped, the refrigerant of the refrigerating system passes only the first evaporator 50.

That is, the refrigerant of the refrigerating system passing through the condenser 30 is introduced into the first expansion device 42 via the branch portion 73. At this time, the first expansion device 42 is in an open state, and the third expansion device 85 may be closed.

The refrigerant passing through the first expansion device 42 is evaporated in the first evaporator 50 to generate cold air. On the other hand, the second compressor 25 is turned off so that the refrigerant does not circulate the refrigeration system, the supply of cold air to the freezer compartment can be stopped.

On the other hand, when the operation of the refrigerating system is stopped and supply of cold air to the refrigerating compartment is stopped, and the refrigerating system is operated, the refrigerant of the refrigerating system passes only the heat exchanger 80.

That is, the refrigerant of the refrigerating system having passed through the condenser 30 is introduced into the bypass passage 83 via the branch portion 73, and passes through the third expansion device 85 to pass through the heat exchanger ( 80). At this time, the first expansion device 42 may be closed, and the third expansion device 85 may be opened. The heat exchanger 80 can then function as an evaporator of the refrigeration system.

The refrigerant of the refrigeration system passes through the second compressor 25 and then flows into the heat exchanger 80 to exchange heat with the refrigerant of the refrigeration system. In this process, the refrigerant of the refrigeration system is condensed, and the refrigerant of the refrigeration system may be evaporated.

On the other hand, when both the refrigeration system and the refrigeration system are stopped, the operation of the first compressor 20 and the second compressor 25 is turned off.

Figure 3 is a block diagram showing the configuration of a refrigeration refrigeration combined system according to an embodiment of the present invention.

Referring to FIG. 3, the complex system 10 according to an embodiment of the present invention includes an input unit 110 for inputting a command regarding whether a refrigeration system or a refrigeration system is operated, and a condensation temperature in operation information of the refrigeration system. (Or a first temperature sensing unit 120 for recognizing the information on the condensation pressure), and a second temperature sensing unit 130 for recognizing the information on the evaporation temperature (or evaporation pressure) of the operation information of the refrigeration system. ), A memory unit 140 in which a predetermined table value is stored to determine an evaporation temperature (or evaporation pressure) of the refrigerating system, and a controller 100 for controlling these components. The first temperature sensing unit 120 and the second temperature sensing unit are referred to as a "temperature sensing unit".

The input unit 110 may include a power input unit selectable for operation of the refrigeration system and the refrigeration system and an operation start command input unit.

The first temperature sensing unit 120 may be disposed at the outlet side of the condenser 30 so that the temperature of the refrigerant passing through the condenser 30, that is, the condensation temperature, may be sensed. When the refrigerant condensed in the condenser 30 is recognized as a two-phase state, the condensation pressure (high pressure) corresponding thereto may be determined. As a result, the condensation pressure may be recognized from the information detected by the first temperature sensing unit 120.

The second temperature sensing unit 130 may be disposed at the outlet side of the second evaporator 55 in the refrigeration system so that the temperature of the refrigerant passing through the second evaporator 55, that is, the evaporation temperature, may be sensed. . When the evaporation temperature of the refrigerant evaporated in the second evaporator 55 is recognized as a two-phase state, a corresponding evaporation pressure (low pressure) may be determined. As a result, the evaporation pressure may be recognized from the information detected by the second temperature sensing unit 130.

For example, when an operation stop command of the refrigerating system is input through the input unit 110 while the refrigerating system and the refrigerating system are operated, the condensation pressure and the second temperature sensed from the first temperature sensing unit 120 are sensed. Using the evaporation pressure recognized from the unit 130, a new evaporation pressure of the refrigeration system is determined as a control criterion.

At this time, the new evaporation pressure (reference pressure) can be determined by the following equation.

Reference pressure = (condensing pressure of refrigeration system * evaporation pressure of refrigeration system) ^1/2

According to the above relation, the reference pressure may be increased in response to an increase in the condensation pressure of the refrigeration system and the evaporation pressure of the refrigeration system.

Information about the relational expression or mapping information for determining a new reference pressure using the two pressure values (condensation pressure and evaporation pressure) may be stored in the memory unit 140 in advance. The reference pressure is recognized as the pressure (evaporation pressure) of the refrigerant of the refrigerating system passing through the heat exchanger 80, and thus the operation of the refrigerating system is controlled.

The control unit 100 controls a plurality of components that can adjust the control pressure (condensation pressure or evaporation pressure) of the refrigerant system according to whether the refrigeration system or the refrigeration system is operated.

For example, the control unit 100 may control the operating frequencies of the first and second compressors 20 and 25 to adjust the degree of compression of the refrigerant circulating in the refrigerating system or the refrigerating system, and the condenser 30 In order to adjust the amount of heat exchange in the) may be adjusted the rotation speed of the blowing fan (35).

In addition, the controller 100 may adjust the first expansion device 42 and the third expansion device 45 to adjust the flow direction or the flow amount of the refrigerant depending on whether the refrigeration system is operated.

By such a configuration, the evaporation pressure of the refrigerant circulating in the refrigeration system can be varied depending on whether the refrigeration system is operating.

Hereinafter, a control method of the complex system 10 according to an exemplary embodiment of the present invention will be described. Figure 4 is a flow chart showing a control method of the refrigeration refrigeration combined system according to an embodiment of the present invention.

Referring to FIG. 4, whether the refrigeration system is operated among the complex system 10 according to an exemplary embodiment of the present invention may be recognized (S11).

For example, when an operation start command of the refrigeration system is input through the input unit 110, the evaporation temperature is set to the first evaporation temperature T1 for the refrigerant cycle circulating in the refrigeration system. Of course, if the first evaporation temperature is determined, the corresponding evaporation pressure (low pressure) may be determined.

When the first evaporation temperature and the evaporation pressure are determined, the operation of the first compressor 20, the blower fan 35, the first expansion device 42 and the third expansion device 85 is controlled by taking into consideration the outdoor temperature. Thus, the operation of the refrigeration system is performed (S12, S13).

On the other hand, when the input for the operation of the refrigeration system is not made or when the operation of the refrigeration system is recognized, that is, when the cold air supply to the refrigerating chamber is not made, the evaporation temperature for the refrigerant cycle circulating the refrigeration system is It is set to the third evaporation temperature (T3). Here, the third evaporation temperature may be a temperature value higher than the first evaporation temperature. For example, the first evaporation temperature may be about −10 ° C., and the third evaporation temperature may be about 0 ° C.

In addition, when the third evaporation temperature is determined, an evaporation pressure (low pressure) corresponding thereto may be determined.

When the operation of the refrigeration system is stopped, as described above, the refrigerant of the refrigeration system is introduced into the heat exchanger 80 and used to condense the refrigerant of the refrigeration system. Therefore, the evaporation temperature of the refrigerating system need not have a value as low as the first evaporation temperature formed to supply cold air to the refrigerating chamber, and thus the third evaporation temperature may be determined as a temperature higher than the first evaporation temperature.

As described above, the third evaporation temperature may be a temperature value corresponding to evaporation pressure = (condensation pressure of the refrigeration system * evaporation pressure of the refrigeration system) ^1/2 (S14).

Then, whether or not the operation of the refrigeration system can be recognized (S15).

For example, when an operation start command of the refrigeration system is input through the input unit 110, the evaporation temperature is set to the second evaporation temperature T2 for the refrigerant cycle circulating in the refrigeration system. In one example, the second evaporation temperature may be -35 ℃. Of course, if the second evaporation temperature is determined, the corresponding evaporation pressure (low pressure) may be determined.

When the second evaporation temperature and the evaporation pressure are determined, the operation of the second compressor 25 and the second expansion device 45 is controlled, and thus the operation of the refrigeration system may be performed (S16 and S17).

On the other hand, when the input for the operation of the refrigeration system is not made or the operation of the refrigeration system is recognized, that is, when the cold air supply to the freezer is not made, the operation of the second compressor 25 may be turned off. There is (S18).

In addition, the operation of the first compressor 20 may be selectively turned off depending on whether the refrigeration system is operated. That is, when the refrigeration system performs step S13, the first compressor 20 is operated. However, when the refrigeration system performs step S14, the necessity of circulating the refrigerant of the refrigeration system is lost, and the operation of the first compressor 20 is turned off.

As such, when the refrigeration system is operated and the refrigeration system is not operated, that is, when the refrigerant of the refrigeration system is used to condense the refrigerant of the refrigeration system in the heat exchanger 80, the evaporation formed during operation of the refrigeration system. At higher evaporation pressures, the refrigerant in the refrigeration system can be circulated.

As a result, the heat exchange efficiency of the refrigeration system is improved, the operation efficiency of the system can be improved.

10: refrigeration refrigeration composite system 20: the first compressor
25: second compressor 30: condenser
35 blowing fan 42 first expansion device
45 second expansion device 50 first evaporator
55: second evaporator 70: first refrigerant pipe
73: branch 76: lamination
80: heat exchanger 83: bypass flow path
85: third expansion device 110: input unit
120: first temperature sensor 130: second temperature sensor

Claims (10)

A first compressor for compressing a refrigerant of the refrigerating system for refrigerating operation of the first predetermined space;
A second compressor for compressing the refrigerant of the refrigeration system for the refrigeration operation of the second set space;
A condenser arranged to pass the refrigerant compressed by the first compressor;
A first evaporator configured to evaporate at least a portion of the refrigerant having passed through the condenser and to supply cold air to the first predetermined space;
A heat exchanger for performing heat exchange between the refrigerant passing through the second compressor and the refrigerant passing through the condenser;
A second evaporator for evaporating the refrigerant passing through the heat exchanger;
A temperature sensing unit sensing at least one of a condensation temperature of the refrigerant passing through the condenser and an evaporation temperature of the refrigerant passing through the second evaporator; And
And a control unit configured to determine a reference pressure passing through the heat exchanger based on the temperature sensing unit when it is recognized that supplying cold air to the first set space is stopped. The method of claim 1,
The temperature sensing unit,
A first temperature sensing unit sensing a condensation temperature of the refrigerant passing through the condenser; And
The refrigeration refrigeration composite system including a second temperature detection unit for detecting the evaporation temperature of the refrigerant passing through the second evaporator. The method of claim 1,
The reference pressure is
Refrigerating and refrigeration combined system, characterized in that higher than the evaporation pressure of the refrigerant passing through the first evaporator in the process of supplying cold air to the first set space. The method of claim 1,
And a plurality of memory units mapped with the plurality of pressure information recognized by the temperature sensing unit and the reference pressure information. The method of claim 1,
Depending on whether the refrigeration system is operating,
Refrigerating and refrigeration combined system, characterized in that the evaporation pressure of the refrigerant circulating the refrigeration system is variable. What is claimed is: 1. A method of controlling a refrigeration refrigeration combined system comprising a refrigeration system in which a refrigeration refrigerant is circulated and a refrigeration system including a refrigeration compressor, a condenser and a first evaporator, and a refrigeration system in which a refrigeration refrigerant is circulated and a refrigeration compressor and a second evaporator. ,
Stopping operation of the refrigerating system and stopping supply of cold air to the refrigerating compartment;
Recognizing the condensation pressure of the refrigerant passing through the condenser;
Recognizing the evaporation pressure of the refrigerant passing through the second evaporator; And
And determining a reference pressure related to evaporation of the refrigerant circulating in the refrigerating system, based on the condensation pressure and the evaporation pressure. The method according to claim 6,
Further comprising a heat exchanger for heat exchange between the refrigerant passing through the condenser and the refrigerant passing through the refrigeration compressor,
And the reference pressure is determined as a refrigerant pressure after passing through the heat exchanger in the refrigeration system. The method according to claim 6,
When the operation of the refrigeration system is performed, the evaporation pressure of the refrigerant passing through the first evaporator is a control method of a refrigeration refrigeration combined system, characterized in that lower than the reference pressure. The method of claim 8,
The evaporation pressure of the refrigerant passing through the second evaporator is lower than the evaporation pressure of the first evaporator. The method of claim 8,
The reference pressure is
If the condensation pressure and the evaporation pressure of the refrigerant passing through the second evaporator increases, the control method of the refrigeration refrigeration complex system, characterized in that the rise.

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