KR101973204B1 - A combined refrigerating and freezing system and a control method the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a cold storage refrigeration combined system and a control method thereof.
The refrigerating and freezing combined system according to an embodiment of the present invention includes a first compressor for compressing a refrigerant for refrigerating operation in a first set space; A second compressor for compressing the refrigerant for freezing operation of the second setting space; A condenser arranged to pass the refrigerant compressed in the first compressor or the second compressor; A first evaporator for evaporating the refrigerant passing through the condenser and supplying cool air to the first setting space; A heat exchanger for performing heat exchange between the refrigerant passing through the second compressor and the refrigerant passing through the condenser, based on the outside temperature condition; And a second evaporator which evaporates the refrigerant condensed in the condenser or the heat exchanger and supplies cool air to the second setting space.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a refrigerated refrigeration combined system and a control method thereof,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a cold storage refrigeration combined system and a control method thereof.

The refrigerating system means that the refrigerant is cooled in the first 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 first predetermined space. The refrigeration system is a refrigeration system in which the refrigeration of an article 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.

Specifically, the refrigeration system includes a first compressor for compressing the refrigerant, a refrigerating condenser for exchanging heat between the refrigerant and the indoor / outdoor air, a refrigeration expansion device for decompressing the refrigerant, An evaporator is included.

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

However, in the related art, there is a problem that the refrigeration system and the refrigeration system are driven separately, which increases the manufacturing cost for constructing the system. In particular, it has been pointed out that the inefficiency of having a separate heat exchanger (e.g., a condenser) to drive the system is a problem.

In the case of the refrigeration system, since a pressure difference between a low pressure (evaporation pressure) and a high pressure (condensation pressure) of a refrigerant cycle that is generally driven is largely formed, a multi-stage compression system is applied in order to appropriately secure the compression ratio. In this case, the use of a plurality of compressors or a compressor to which a multi-stage compression method is applied has a problem in that the cost of implementing the system is increased.

On the other hand, in the process of driving the refrigeration system using the multi-stage compression system, when the outside air temperature is low, the condensation pressure is low and the compression ratio of the compressor is too low.

In order to solve such a problem, the present invention aims to provide a refrigerating and freezing combined system in which a refrigerating and freezing system is composed in a complex manner and a heat exchange system is applied differently according to the ambient temperature.

The refrigerating and freezing combined system according to an embodiment of the present invention includes a first compressor for compressing a refrigerant for refrigerating operation in a first set space; A second compressor for compressing the refrigerant for freezing operation of the second setting space; A condenser arranged to pass the refrigerant compressed in the first compressor or the second compressor; A first evaporator for evaporating the refrigerant passing through the condenser and supplying cool air to the first setting space; A heat exchanger for performing heat exchange between the refrigerant passing through the second compressor and the refrigerant passing through the condenser, based on the outside temperature condition; And a second evaporator which evaporates the refrigerant condensed in the condenser or the heat exchanger and supplies cool air to the second setting space.

According to another aspect of the present invention, there is provided a control method for a refrigerating and freezing combined system including a refrigerant compressor in which refrigerant for refrigerating is compressed, a refrigerant compressor in which refrigerant for refrigerant is compressed, a condenser in which refrigerant having passed through the refrigerant compressor or refrigerant compressor is condensed, A method for controlling a refrigerating and refrigeration combined system including an evaporator, the method comprising: sensing an outside temperature; Determining whether the sensed outdoor temperature is equal to or higher than a predetermined temperature; If the sensed outdoor temperature is higher than or equal to the preset temperature, operating the flow switching unit to introduce the refrigerant for refrigeration into the heat exchanger; And refrigerant refrigerant passing through the condenser and refrigerant refrigerant passing through the refrigerant compressor are heat-exchanged in a heat exchanger.

According to the embodiment of the present invention, since the refrigeration system and the refrigeration system are combined, heat exchange can be performed using one condenser, so that the system can be easily configured and the refrigeration and freezing operation can be performed at the same time.

In addition, by adopting different heat radiating mechanisms of the refrigeration system according to the ambient temperature, there is an effect that the refrigeration refrigeration combined system can be effectively driven by only one refrigeration compressor.

That is, when the outside air temperature is relatively high, the compression ratio of the compressor can be lowered by passing the refrigerant that has passed through the refrigeration side compressor to the heat exchanger (cascade heat exchanger), thereby increasing the reliability of the compressor operation, There is an advantage that it can be improved.

When the outside air temperature is relatively low, the refrigerant that has passed through the refrigerating side compressor is passed through the condenser, thereby preventing the unnecessary decrease in the compression ratio due to the use of the heat exchanger and reducing the amount of power consumption.

1 is a system diagram showing a configuration of a cold storage and refrigeration combined system according to an embodiment of the present invention.
2 is a block diagram showing a configuration of a cold storage and refrigeration combined system according to an embodiment of the present invention.
3 is a view showing the flow of refrigerant circulating in the refrigerating and freezing combined system when the outside air temperature is relatively low.
4 is a view showing the flow of refrigerant circulating in the refrigerating and freezing combined system when the outside air temperature is relatively high.
FIG. 5 is a flowchart illustrating a control method of a cold storage and 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.

1 is a system diagram showing a configuration of a cold storage and refrigeration combined system according to an embodiment of the present invention.

Referring to FIG. 1, a refrigerating and freezing combined system (hereinafter, referred to as a "combined system") according to an embodiment of the present invention includes a refrigerating system and a refrigerating system in combination.

In detail, the refrigeration system includes a first compressor 10 for compressing the refrigerant, a condenser 30 for condensing the refrigerant compressed in the first compressor 10, an air blower for blowing outside air to the condenser 30, A fan 35 and a first expansion device 42 for reducing the pressure of the refrigerant condensed in the condenser 30 and a first evaporator 50 for evaporating the refrigerant through the first expansion device 42. The first compressor (10) and the first evaporator (50) may be referred to as "refrigerating compressor" and "refrigerating evaporator", respectively.

The refrigeration system includes a second compressor 20 for compressing the refrigerant, a condenser 30 for condensing the refrigerant compressed by the second compressor 20, a blowing fan (not shown) for blowing outside air to the condenser 30 A second expansion device 45 for reducing the pressure of the refrigerant condensed in the condenser 30 and a second evaporator 60 for evaporating the refrigerant through the second expansion device 45. The second compressor (20) and the first evaporator (60) may be referred to as "refrigeration compressor" and "freezer evaporator", respectively.

The refrigeration system and the refrigeration system are characterized in that the first and second compressors 10 and 20 are connected in parallel to each other, and the refrigerant compressed in each compressor is heat exchanged with the outside air in one condenser 30.

The hybrid system (1) includes a refrigerant pipe (70) for guiding the refrigerant to circulate through the refrigeration system or the refrigeration system. The refrigerant pipe 70 is provided with a first pipe portion for connecting the first compressor 10, the condenser 30, the first expansion device 42 and the first evaporator 50, Quot; second piping portion " connecting the first evaporator 20, the condenser 30, the second expansion device 45 and the second evaporator 60 are included.

The refrigerant pipe 70 includes a first branch portion 72 for allowing the refrigerant passing through the condenser 30 to branch and flow to the first expansion device 42 and the second expansion device 45 . That is, some of the refrigerant that has passed through the condenser 30 flows to the first expansion device 42, and the remaining refrigerant can flow to the second expansion device 45.

The hybrid system (1) includes a heat exchanger (80) for exchanging heat between a refrigerant circulating in the refrigeration system and a refrigerant circulating in the refrigeration system when the outside air temperature is above a predetermined range. The heat exchanger 80 may be referred to as a " cascade heat exchanger ". The heat exchanger 80 is connected in parallel with the condenser 30 and the refrigerant compressed in the second compressor 20 can be selectively introduced into either the condenser 30 or the heat exchanger 80.

The refrigerant pipe (70) includes a second branch portion (73) for allowing at least a part of the refrigerant passing through the condenser (30) to be branched by the heat exchanger (80). That is, the refrigerant passing through the condenser 30 may be branched from the second branched portion 73 to the first expansion device 42 and the heat exchanger 80 side.

The combined system 1 includes a bypass passage 83 extending from the second branch 73 to the inlet side of the heat exchanger 80. The bypass passage 83 bypasses at least a part of the refrigerant in the refrigerant passing through the condenser 30 and flows into the heat exchanger 80 side.

The bypass passage 83 is provided with a third expansion device 85 disposed at the inlet side of the heat exchanger 80 for reducing the pressure of the refrigerant to be introduced into the heat exchanger 80. According to the adjustment of the opening degree of the third expansion device 85, at least a part of the refrigerant flowing through the condenser 30 may be introduced into the bypass flow passage 83.

For example, when the third expansion device 85 is closed, all of the refrigerant that has passed through the third condenser 30 can be guided to the first expansion device 42. On the other hand, when the third expansion device 85 is at least partially opened, at least a part of the refrigerant passing through the third condenser 30 may flow into the bypass flow passage 83.

The second pipe portion of the refrigerant pipe (70) includes a flow control portion (95) for allowing the refrigerant to selectively flow from the first branch portion (72) to the second expansion device (45). The flow regulating portion 95 may be a valve device.

When the flow regulating portion 95 is opened, the refrigerant can flow from the first branched portion 72 to the second expansion device 45. On the other hand, when the flow regulating portion 95 is closed, the flow of refrigerant from the first branched portion 72 to the second expansion device 45 can be restricted.

A pipe through which the refrigerant of the refrigerating system heat-exchanged in the heat exchanger (80) flows and a refrigerant passing through the flow regulating portion (45) are provided between the flow regulating portion (95) and the second expansion device A pipe connecting portion 76 is formed in which the flowing pipe is joined.

The refrigerant that has passed through the flow regulating portion 95 from the first branch portion 72 flows into the second expansion device 45 via the pipe connection portion 76, . On the other hand, if the outdoor temperature is higher than the set temperature, the refrigerant passing through the heat exchanger 80 may be introduced into the second expansion device 45 via the pipe connection part 76.

In the combined system 1, the refrigerant of the refrigeration system passing through the first compressor 10 and the refrigerant of the refrigeration system passing through the second compressor 20 are connected to each other, A first joint portion 74 is formed. For example, when the outdoor temperature is lower than the set temperature, the refrigerant of the refrigeration system and the refrigerant of the refrigeration system may be mixed in the first joint portion 74.

The inlet of the first compressor 10 is provided with a second joint portion for coupling the refrigerant of the refrigeration system that has passed through the first evaporator 50 and the refrigerant of the refrigeration system that has passed through the heat exchanger 80 76 are formed. For example, when the outside air temperature is higher than the predetermined temperature, the refrigerant passing through the first evaporator 50 and the refrigerant passing through the heat exchanger 80 may be joined together at the second joint portion 76.

A flow switching unit 93 for switching the direction of the refrigerant to guide the refrigerant discharged from the second compressor 20 to the condenser 30 or the heat exchanger 80 is provided at the outlet side of the second compressor 20 / RTI > The flow switching unit 93 may be a three-way valve.

For example, the flow switching unit 93 is controlled so that the refrigerant discharged from the second compressor 20 flows into the condenser 30 when the outdoor temperature is below the set temperature. On the other hand, when the outdoor temperature is higher than the set temperature, the refrigerant discharged from the second compressor (20) is adjusted to flow into the heat exchanger (80).

FIG. 2 is a block diagram showing a configuration of a refrigerating and freezing combined system according to an embodiment of the present invention, FIG. 3 is a view showing a flow of refrigerant circulating in a refrigerating and freezing combined system when the outside air temperature is relatively low, Is a diagram showing the flow of refrigerant circulating in the refrigerating and freezing combined system when the outside air temperature is relatively high.

Referring to FIG. 2, the hybrid system 1 according to the embodiment of the present invention includes an outside temperature sensing unit 110 for recognizing the outside air temperature, A control unit 100 for controlling the operation of the third expansion device 85, the flow switching unit 93, and the flow control unit 95 based on information recognized by the outside air temperature sensing unit 110, .

Referring to FIGS. 3 and 4, the change in the refrigerant flow according to the outside temperature will be described.

First, FIG. 3 shows the refrigerant flow when the outside air temperature is relatively low, for example, below the set temperature.

Specifically, when the outside air temperature is lower than the set temperature, the refrigerant in the refrigeration system flows to circulate through the first compressor 10, the condenser 30, the first expansion device 42, and the first evaporator 50. Then, the refrigerant in the refrigeration system flows to circulate through the second compressor (20), the condenser (30), and the second evaporator (60).

In detail, the refrigerant of the refrigeration system discharged from the first compressor (10) and the refrigerant of the refrigerant system discharged from the second compressor (20) are connected to the condenser (30) ≪ / RTI >

The refrigerant that has passed through the condenser 30 is branched at the second branch 72 and flows to the first expansion device 42 and the second expansion device 45.

At this time, the flow regulating portion 95 is opened so that at least a portion of the refrigerant (refrigerant of the refrigerating system) is guided to pass through the second expansion device 45 in the first branch portion 72. The refrigerant decompressed in the second expansion device (45) is evaporated in the second evaporator (60) and introduced into the second compressor (20).

The remaining refrigerant (refrigerant in the refrigeration system) of the refrigerant that has passed through the condenser 30 flows into the first expansion device 42 from the first branch 72. The refrigerant decompressed in the first expansion device (42) is evaporated in the first evaporator (50) and introduced into the first compressor (10). This cycle is repeated.

On the other hand, when the outside air temperature is lower than the set temperature, the third expansion device 85 is closed, so that the refrigerant passing through the condenser 30 is branched from the second branch 73, Is limited. The flow switching unit 93 is controlled such that refrigerant discharged from the second compressor 20 can be introduced into the condenser 30.

In this way, when the outdoor temperature is lower than the set temperature, heat exchange is not generated in the heat exchanger 80, and the refrigerant in the refrigeration system can be radiated by using the condenser 30 that performs heat exchange with the outside air.

That is, when the outside air temperature is lower than the set temperature, the condensation temperature (condensation pressure) of the system is relatively low, so that the refrigerant compressed in the first compressor 10 and the second compressor 20 is mixed, Lt; / RTI >

Accordingly, even if only one compressor of the refrigeration system operates, it is possible to prevent an increase in power consumption because the compressor is not overloaded and the heat exchanger 80 is used separately.

First, FIG. 4 shows the refrigerant flow when the outside air temperature is relatively low, for example, when the temperature is higher than the set temperature.

More specifically, when the outside air temperature is equal to or higher than the set temperature, the refrigerant in the refrigeration system flows through the first circulation cycle in which the refrigerant circulates through the first compressor 10, the condenser 30, the first expansion device 42 and the first evaporator 50 A second circulation cycle for circulating the first compressor 10, the condenser 30, the third expansion device 85 and the heat exchanger 80 is formed.

Then, the refrigerant of the refrigeration system flows to circulate through the second compressor (20), the heat exchanger (80), the second expansion device (45) and the second evaporator (60).

In detail, the refrigerant of the refrigeration system discharged from the first compressor (10) is condensed in the condenser (30) and branched at the second branch (73). At least a portion of the refrigerant branched in the second branch 73 is expanded in the first expansion device 42 and passes through the first evaporator 50. The remaining refrigerant branched in the second branch 73, A part of the refrigerant expands in the third expansion device 85 and passes through the heat exchanger 80. [

At this time, the third expansion device 85 is opened to guide the inflow of the refrigerant into the heat exchanger 80, and inflates the refrigerant flowing into the heat exchanger 80. In order to prevent the refrigerant from flowing from the first branched portion 72 to the second expansion device 45, the flow regulating portion 95 may be closed.

The refrigerant that has passed through the first evaporator 50 and the refrigerant that has passed through the heat exchanger 80 are joined together by the second joint portion 76 and then introduced into the first compressor 10 again. By this refrigerant flow, the refrigerant in the refrigeration system is circulated.

On the other hand, the refrigerant of the refrigerant system discharged from the second compressor (20) flows from the flow switching unit (93) to the heat exchanger (80) side. That is, the flow switching unit 93 guides the refrigerant to the heat exchanger 80. The refrigerant in the refrigeration system is heat-exchanged with the refrigerant in the refrigeration system in the heat exchanger (80).

The refrigerant in the refrigeration system that has passed through the heat exchanger (80) is depressurized in the second expansion device (45) and evaporated in the second evaporator (60). The evaporated refrigerant flows into the second compressor (20), and the refrigerant in this refrigeration system is circulated.

In this way, when the outside air temperature is higher than the set temperature, the refrigerant of the refrigerating system and the refrigerant of the refrigerating system heat exchange in the heat exchanger (80). That is, the refrigerant in the refrigeration system can be discharged using the heat exchanger (80).

In summary, when the outdoor temperature is equal to or higher than the set temperature, the refrigerant of the refrigerating system is heat-exchanged in the condenser 30, the condensation temperature (condensation pressure) of the system is relatively high. Therefore, the compression ratio to be compressed by the second compressor 20 is high So that the second compressor 20 is able to follow the load.

In order to prevent this, the refrigerant passing through the condenser 30 is partially expanded to heat-exchange the refrigerant in the refrigerant system, so that the temperature at which the refrigerant in the refrigerant system is condensed can be lowered. As a result, by reducing the compression ratio of the refrigerant compressor 20, reliability of the operation of the compressor can be improved and the performance coefficient of the system can be improved.

FIG. 5 is a flowchart illustrating a control method of a cold storage and refrigeration combined system according to an embodiment of the present invention. A control method of the hybrid system according to the embodiment of the present invention will be described with reference to FIG.

When the operation of the combined system is started, the first compressor (10) and the second compressor (20) are driven. During the operation of the first and second compressors 10 and 20, the outside air temperature sensing unit 110 senses the outside air temperature. Then, whether or not the outside air temperature is equal to or higher than the set temperature can be recognized. Here, the set temperature may be determined as a set value in a range of about 1 캜 to 10 캜 (S11, S12, S13).

When the outdoor temperature is equal to or higher than the set temperature, the third expansion device (85) is opened. Therefore, at least a portion of the refrigerant condensed in the condenser 30 flows from the second branch 73 to the third expansion device 85. [ The refrigerant decompressed in the third expansion device 85 (refrigerant in the refrigeration system) flows into the heat exchanger 80 (S14).

Then, the flow regulating portion 95 is closed. Accordingly, the refrigerant condensed in the condenser 30 is restricted from flowing from the first branched portion 72 to the second expansion device 45 (S15).

The flow switching unit 93 is controlled in a first direction so that refrigerant compressed by the second compressor 20 (refrigerant of the refrigerating system) flows into the heat exchanger 80. In the heat exchanger 80, heat exchange is performed between the refrigerant of the refrigerating system and the refrigerating system, so that the refrigerant of the refrigerating system can be condensed (heat dissipation) (S16, S17).

On the other hand, if the outside air temperature is lower than the set temperature in step S13, the third expansion device 85 is closed. Accordingly, the refrigerant condensed in the condenser 30 is restricted from flowing from the second branched portion 73 to the heat exchanger 80 (S18).

Then, the flow regulating portion 95 is opened. Thus, at least a portion of the refrigerant condensed in the condenser 30 flows as refrigerant in the refrigeration system from the first branch 72 to the second expansion device 45. [

The refrigerant flowing into the second expansion device (45) is evaporated in the second evaporator (60) and introduced into the second compressor (20). The remaining refrigerant branched from the first branched portion 72 flows into the first compressor 10 through the first expansion device 42 and the first evaporator 50 (S19).

The flow switching unit 93 is controlled in the second direction so that the refrigerant compressed in the second compressor 20 bypasses the heat exchanger 80 and flows into the condenser 30. [

The refrigerant of the refrigeration system and the refrigerant system in the first joint portion 74 flow into the condenser 30, and the refrigerant and the external heat exchange may be performed in the condenser 30. That is, the refrigerant circulating in the refrigeration system may be condensed (heat-dissipated) in the condenser 30 (S20, S21).

1: Refrigerated refrigeration combined system 10: First compressor
20: second compressor 25: third compressor
30: condenser 35: blowing fan
42: first expansion device 45: second expansion device
50: first evaporator 60: second evaporator
70: refrigerant pipe 72, 73:
80: heat exchanger 85: third expansion device
93: flow switching unit 95: flow control unit

Claims (10)

A first compressor for compressing the refrigerant for the refrigerating operation of the first setting space;
A second compressor for compressing the refrigerant for freezing operation of the second setting space;
A condenser arranged to pass the refrigerant compressed in the first compressor or the second compressor;
A first evaporator for evaporating the refrigerant passing through the condenser and supplying cool air to the first setting space;
A heat exchanger for performing heat exchange between the refrigerant passing through the second compressor and the refrigerant passing through the condenser, based on the outside temperature condition;
A second evaporator which evaporates the refrigerant condensed in the condenser or the heat exchanger and supplies cool air to the second setting space;
A flow switching unit switching the refrigerant flow so that the refrigerant compressed in the second compressor flows into one of the condenser and the heat exchanger;
A first branching part for causing the refrigerant passing through the condenser to branch to the first evaporator and the second evaporator;
A second branch portion for allowing the refrigerant passing through the condenser to branch to the heat exchanger; And
And a bypass flow path extending from the second branch to the heat exchanger and guiding the refrigerant having passed through the condenser to flow into the heat exchanger. delete The method according to claim 1,
Further comprising an expansion device provided in the bypass flow path for expanding the refrigerant. The method of claim 3,
Further comprising a flow regulating unit selectively limiting a flow of refrigerant from the first branch to the second evaporator. The method of claim 3,
If the outside air temperature is higher than the set temperature,
Wherein the refrigerant compressed in the second compressor and the refrigerant flowing in the bypass channel are heat-exchanged in the heat exchanger. 5. The method of claim 4,
If the outside air temperature is lower than the set temperature,
And the refrigerant compressed in the second compressor bypasses the heat exchanger and flows into the condenser. A refrigerating compressor in which refrigerating refrigerant is compressed, a refrigerating compressor in which refrigerating refrigerant is compressed, a condenser in which refrigerant having passed through the refrigerating compressor or refrigerating compressor is condensed, a refrigerating evaporator in which refrigerant passing through the condensing device is evaporated, A condenser and a condenser; a refrigerant compressor for condensing the refrigerant; a condenser for condensing the refrigerant; a condenser for condensing the refrigerant; a condenser for condensing the refrigerant; And a bypass flow path for guiding the refrigerant passing through the condenser to flow into the heat exchanger, the method comprising the steps of:
Detecting an outside temperature;
Determining whether the sensed outdoor temperature is equal to or higher than a predetermined temperature;
If the sensed outdoor air temperature is equal to or higher than the set temperature, operating the flow switching unit to introduce the refrigerant for refrigeration into the heat exchanger;
And a refrigerant refrigerant passing through the condenser and a refrigerant refrigerant passing through the refrigerant compressor are heat-exchanged in the heat exchanger. 8. The method of claim 7,
If the sensed outdoor temperature is below the set temperature,
Wherein the flow switching unit is operated to bypass the refrigerant for cooling the refrigerant to the heat exchanger and flow into the condenser. 8. The method of claim 7,
If the sensed outdoor temperature is equal to or higher than the set temperature,
Wherein the refrigerant for cooling refrigerant passing through the condenser is depressurized and then introduced into the heat exchanger. 8. The method of claim 7,
Wherein the condenser and the heat exchanger are connected in parallel.

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