KR20190128360A - Cooling system for a low temperature storage - Google Patents

Abstract

The present invention relates to a cooling system of a low-temperature storage. According to an embodiment of the present invention, the cooling system of the low-temperature storage comprises: a flow control valve connected to a discharge pipe of a compressor; an outdoor heat exchanger arranged on an outlet side of the flow control valve; and a bypass pipe extending from a first branch unit of the discharge pipe to guide a refrigerant to pass by the outdoor heat exchanger. Accordingly, defrosting and cooling operation of first and second evaporators can be performed at the same time.

Description

Cooling system for a low temperature storage

The present invention relates to a cooling system of a cold storage.

A cooling system for cooling a cold storage can generally be understood as a cooling system for cooling a cold store, especially a large warehouse of a plant where the temperature of the air must be maintained or a food storage (showcase) requiring refrigeration / freezing.

In the process of driving the cooling system, the phenomenon of implantation may occur in the evaporator included in the system. In order to remove the idea, the cooling system performs a defrosting operation. For example, the defrosting operation may be performed periodically, or may be performed when the evaporator temperature of the evaporator is below a set temperature.

Conventionally, in order to perform the defrosting operation, the cooling system is configured such that an electric heater is installed at a position adjacent to the evaporator. When the electric heater is driven, heat generated in the electric heater is transferred to the evaporator, the idea could be removed.

Related patent information is as follows.

[Previous Patent Document]

Registration Number: 10-1266936, Registration Date: May 16, 2013

Name of invention: Eco-friendly storage control device to reduce carbon generation

However, according to the conventional defrosting method by the heater, there existed the following problems.

First, there was a problem that the cost is increased by the consumption of excessive electrical energy.

Second, while the defrosting operation by the heater is performed, the cooling operation through the evaporator is stopped to increase the temperature of the storage, thereby reducing the freshness of the food stored in the storage.

Third, there is a problem that the replacement or repair cost of the heater increases due to frequent failure of the heater.

The present invention has been proposed to solve this problem, and an object of the present invention is to provide a cooling system of a low temperature reservoir, which can perform defrosting operation of a first evaporator using hot gas.

In addition, an object of the present invention is to provide a cooling system of a low temperature reservoir in which a condensed refrigerant having undergone defrosting is expanded and evaporated in a second evaporator so that a cooling operation can be simultaneously performed with a defrosting operation.

In particular, by guiding the bypassed hot gas refrigerant at the outlet side of the compressor to the evaporator via the defrosting device, one of the first and second evaporators can be defrosted and the cooling operation can be simultaneously performed using the other evaporator. Can be.

In addition, by cooling the refrigerant passing through the evaporator during the defrosting operation to the outdoor heat exchanger, the outdoor heat exchanger acts as an evaporator during the defrosting operation, the cooling system of the low-temperature reservoir to obtain the required amount of defrost heat from the outdoor air heat source. It aims to provide.

In the cooling system of the cold storage according to the embodiment of the present invention, a flow control valve connected to the discharge pipe of the compressor, an outdoor heat exchanger disposed on the outlet side of the flow control valve and extending from the first branch of the discharge pipe In addition, a bypass pipe may be included to guide the refrigerant to bypass the outdoor heat exchanger, and defrosting and cooling operations of the first and second evaporators may be simultaneously performed.

In addition, a suction connection pipe extending from the flow control valve and guiding the refrigerant passing through the outdoor heat exchanger to the suction side of the compressor is further included, and the refrigerant evaporated in the outdoor heat exchanger can be easily sucked into the compressor.

The first evaporator in which the refrigerant flowing through the bypass pipe is introduced and defrosting may be performed, and a second evaporator disposed at an outlet side of the first evaporator, and the refrigerant passing through the first evaporator may be further evaporated.

A connection pipe connected to the bypass pipe and a first defrost valve coupled to the connection pipe are further included, and the refrigerant flowing through the bypass pipe passes through the connection pipe and the first defrost valve to the first evaporator. Inflow, defrosting of the first evaporator can be easily performed.

A first evaporator discharge pipe extending from the first defrost valve to the first evaporator may be further included.

A connection pipe branched from the connection pipe and a second defrost valve coupled to the connection pipe are further included, and the defrosting operation of the second evaporator can be easily performed.

A second evaporator discharge pipe extending from the second defrost valve to the second evaporator may be further included.

Is connected to the outdoor liquid pipe, and further comprises a first connection pipe is installed defrost expansion device for decompression of the refrigerant and the evaporator inlet pipe connected to the first connection pipe, any one of the first evaporator and the second evaporator The defrosted refrigerant can easily flow into the liquid pipe or the other evaporator.

The liquid pipe may further include an outdoor expansion device for depressurizing the refrigerant, thereby simplifying the configuration of the connection unit.

The flow switching valve includes a four sides, the four sides, the first port coupled to the discharge pipe; A second port coupled to the valve connecting pipe; And a third port coupled to the suction connector.

According to the present invention according to the above solution, since the defrosting operation of the first evaporator can be performed using hot gas, the defrosting time can be shortened and energy consumption for defrosting can be reduced.

In addition, since the condensed refrigerant having defrosted can be expanded and evaporated in the second evaporator, the cooling operation can be simultaneously performed with the defrosting operation.

In addition, by guiding the refrigerant that defrosted the first evaporator to an outdoor heat exchanger and allowing the outdoor heat exchanger to act as an evaporator during defrosting operation, the amount of heat required for defrosting can be obtained from an outdoor air heat source, thereby improving efficiency of defrosting operation. Can be.

1 is a cycle diagram showing a configuration of a cooling system according to a first embodiment of the present invention.
FIG. 2 is an enlarged view of "A" in FIG. 1.
3 is a cycle diagram showing the flow of the refrigerant when performing the cooling operation of the cooling system according to the first embodiment of the present invention.
4 is a cycle diagram showing the flow of the refrigerant when the defrosting operation of the first evaporator according to the first embodiment of the present invention.
5 is a cycle diagram showing the flow of the refrigerant when the defrosting operation of the second evaporator according to the first embodiment of the present invention.
6 is a cycle diagram showing a configuration of a cooling system according to a second embodiment of the present invention.

Hereinafter, with reference to the drawings will be described a specific embodiment of the present invention. However, the spirit of the present invention is not limited to the embodiments presented, and those skilled in the art who understand the spirit of the present invention can easily suggest other embodiments within the scope of the same idea.

1 is a cycle diagram showing a configuration of a cooling system according to a first embodiment of the present invention, Figure 2 is an enlarged view "A" of FIG.

1 and 2, a cooling system 1 according to an embodiment of the present invention includes an outdoor unit 10 disposed outdoors and an indoor unit disposed in a reservoir and supplying cold air to maintain a low temperature of the reservoir ( 30) and a connection unit 50 connected between the outdoor unit 10 and the indoor unit 30 to guide the flow of the refrigerant when the defrosting operation of the cooling system 10 is performed. In one example, the cooling system 1 may cool the reservoir so that the internal temperature of the reservoir is kept below zero.

The connection unit 50 may be understood as a "defrost apparatus", which is composed of a plurality of refrigerant pipes and valves for guiding the flow of the refrigerant to enable the defrosting operation.

The outdoor unit 10 may be detachably connected to the connection unit 50. In detail, the outdoor unit 10 and the connection unit 50 may be connected to the three pipes. The outdoor unit 10 may include a first service valve 175 connected to the liquid pipe 170 and a second service valve 255 connected to the engine 111. In addition, the outdoor unit 10 may further include a third service valve 176 connected to the bypass pipe 130. The bypass pipe 130 may be understood as a pipe through which a high pressure hot gas refrigerant flows.

The connection unit 50 may be provided with three connection parts C1, C2, and C3 connected to the outdoor unit 10. The three connection parts C1, C2, and C3 include a first connection part C1 connected to the first service valve 175 of the outdoor unit 10, and a second service valve 255 of the outdoor unit 10. And a third connection portion C3 connected to the third connection portion C3 connected to the third service valve 176 of the outdoor unit 10. The fourth connector 219 of the connection unit 50 may be connected to the third connector C3.

The cooling system 1 includes a first system pipe 175a connecting the first service valve 175 and the first connection part C1, the second service valve 255, and the second connection part ( A second system pipe 255a connecting C2) and a third system pipe 176a connecting the third service valve 176 and the third connection part C3 are included.

The connecting unit 50 and the indoor unit 30 may be connected to the three pipes. The connection unit 50 may be provided with three connection parts C4, C5, and C6 connected to the indoor unit 30. The three connection parts C4, C5, and C6 include a fourth connection part C4 connected to the evaporator inlet pipe 210 provided in the indoor unit 30, and a fifth connection part connected to the first evaporator outlet pipe 227. A sixth connection part C6 connected to the connection part C5 and the second evaporator outlet pipe 237 is included.

The outdoor unit 10 includes a compressor 110 for compressing a refrigerant, a suction pipe 112 connected to an inlet side of the compressor 110, and guides the refrigerant suction to the compressor 110, and the compressor 110. Is connected to the outlet side of the discharge pipe 114 for guiding the discharge of the refrigerant compressed by the compressor 110 is included.

The suction pipe 112 may be understood as a configuration of an engine extending from the gas-liquid separator 105 to the suction port of the compressor 110 to guide the flow of the refrigerant. The gas-liquid separator 105 may be disposed on the suction side of the compressor 110 as a component for separating and supplying gaseous refrigerant to the compressor 110. The suction pipe 112 guides the refrigerant discharged from the gas-liquid separator 105 to the suction port of the compressor 110.

The outdoor unit 10 may further include an engine 111 extending from the second service valve 255 to the gas-liquid separator 105. Evaporated gaseous refrigerant may flow in the engine 111.

The discharge pipe 114 is understood as a pipe extending from the discharge port of the compressor 110 to the flow switching valve 120, the guide so that the discharge refrigerant of the compressor 110 flows into the flow switching valve 120 do. For example, the flow switching valve 120 may include a four-way valve, and the four sides may include four ports 120a to 120d through which refrigerant is introduced or discharged. The discharge pipe 114 may be coupled to the first port 120a of the flow switching valve 120.

The outdoor unit 10 is installed in the discharge pipe 114, the oil separator 115 for separating the oil discharged with the refrigerant in the compressor 110 and the suction pipe 112 from the oil separator 115. Further includes a recovery pipe 116 extending to. The oil flowing through the recovery pipe 116 may be recovered to the compressor 110. The recovery pipe 116 may be provided with an oil amount adjusting device 117 for adjusting (reducing) the flow rate of the oil to be recovered. For example, the oil amount adjusting device 117 may include a capillary tube.

The discharge pipe 114 may be provided with a first check valve 118 to allow only one-way flow of the refrigerant. The first check valve 118 allows the refrigerant flow from the compressor 110 to the flow switching valve 120, and may limit the refrigerant flow in the opposite direction. For example, the first check valve 118 may be disposed at the outlet side of the oil separator 115.

The discharge pipe 114 is provided with a first branch 119 to which the bypass pipe 130 is connected. For example, the first branch 119 may be located between the first check valve 118 and the first port 120a of the flow switching valve 120. The high pressure hot gas refrigerant flowing through the discharge pipe 114 may be branched from the first branch 119 and introduced into the bypass pipe 130.

At the outlet side of the flow switching valve 120, an outdoor heat exchanger 140 may be installed. The outdoor heat exchanger 140 is a device for performing heat exchange between the refrigerant and the outside air, and an outdoor fan 140a for blowing outside air to the outdoor heat exchanger 140 may be provided at one side of the outdoor heat exchanger 140. have. When the outdoor fan 140a is driven, the refrigerant flowing through the outdoor heat exchanger 140 and the outside air may exchange heat.

The outdoor unit 10 further includes a valve connection pipe 121 extending from the flow switching valve 120 to the outdoor heat exchanger 140. The valve connecting pipe 121 may extend from the second port 120b of the flow switching valve 120 to the outdoor heat exchanger 140.

The liquid pipe 170 is connected to the outlet side of the outdoor heat exchanger 140. The liquid pipe 170 may extend from the outdoor heat exchanger 140 to the first service valve 175.

Receiver 160 may be installed in the liquid pipe 170. The receiver 160 may form a chamber for storing the refrigerant condensed in the outdoor heat exchanger 140. The liquid refrigerant stored in the chamber may flow toward the first service valve 175.

On the outlet side of the receiver 160, a subcooler 164 may be installed. In the subcooler 164, heat exchange may be performed between the main refrigerant condensed in the outdoor heat exchanger 140 and the branched refrigerant branched from the main refrigerant.

The outdoor unit 10 further includes an injection pipe 165 which is branched from the liquid pipe 170 to extend to the compressor 110 and guides the branched refrigerant to the compressor 110. The injection pipe 165 may be provided with a subcooled expansion device 167 for reducing the branched refrigerant.

Through the heat exchange in the subcooler 164, the main refrigerant may be subcooled, and the branch refrigerant may be vaporized and injected into the compressor 110.

The outdoor unit 10 further includes a bypass pipe 130 for guiding the high pressure refrigerant (hot gas refrigerant) compressed by the compressor 110 to bypass the outdoor heat exchanger 140. The bypass pipe 130 may extend from the first branch portion 119 and be connected to the third service valve 176. That is, one end of the bypass pipe 130 may be connected to the first branch 119 and the other end may be connected to the third service valve 176.

When the defrosting operation of the cooling system 1 is performed, the flow switching valve 120 may be operated and controlled in one mode. At this time, the first port 120a and the fourth port 120d of the flow switching valve 120 communicate with each other. The fourth port 120d may be configured to be blocked. Thus, the flow switching valve 120 may perform a function such as "three directions". As a result, the hot gas refrigerant compressed by the compressor 110 may not flow into the flow switching valve 120, but may branch from the first branch 119 and flow through the bypass pipe 130. .

The outdoor unit 10 further includes a suction connection pipe 125 extending from the third port 120c of the flow switching valve 120 to the second branch 113 of the engine 111. One end of the suction connector 125 may be coupled to the third port 120c, and the other end thereof may be coupled to the second branch 113. The second branch portion 113 is a point at which the suction connecting pipe 125 and the engine 111 are connected, and may be disposed at an inflow side of the gas-liquid separator 105.

During the defrosting operation of the cooling system 1, the refrigerant evaporated in the outdoor heat exchanger 140 flows through the suction connecting pipe 125 and flows through the engine 111 in the second branch 113. It can be combined with a gaseous refrigerant. In addition, the laminated refrigerant may be sucked into the compressor 110.

The connecting unit 50 includes a first connecting pipe 214 extending from the first connecting portion C1 to the fourth connecting portion C4. Defrost expansion device 215 may be installed in the first connecting pipe 214. For example, the defrost expansion device 215 may include an electronic expansion valve (EEV) capable of reducing the pressure of the refrigerant.

The connecting unit 50 further includes a second connecting pipe 217 extending from the fifth connecting part C5 to the second connecting part C2. A second defrost valve 228 may be installed in the second connection pipe 217. For example, the first defrost valve 228 may include a three-way valve.

The connecting unit 50 further includes a third connecting pipe 218 extending from the sixth connecting part C6 to the second connecting pipe 217. The third connector 218 may be connected to the second connector 217 at the third branch portion 227a of the second connector 217. The second defrost valve 238 may be installed in the third connection pipe 218. For example, the second defrost valve 238 may include a three-way valve.

The connecting unit 50 further includes a fourth connecting pipe 219 extending from the third connecting part C3 to the first defrost valve 228. The fourth connector 219 may be connected to the first connector 214 at the sixth branch portion 214b of the first connector 214.

The fourth branch pipe 219 is provided with a fourth branch portion 219a. The connection pipe 242 is connected to the fourth branch portion 219a. The connection pipe 242 may be branched from the fourth branch portion 219a and connected to the second defrost valve 238. That is, one end of the connection pipe 242 may be connected to the fourth branch portion 219a, and the other end may be connected to the second defrost valve 238.

The first and second ports of the second defrost valve 238 may be connected to the third connection pipe 218, and the third port may be connected to the connection pipe 242. The first and second ports of the first defrost valve 228 may be connected to the second connection pipe 217, and the third port may be connected to the fourth connection pipe 219.

During the defrosting operation of the cooling system 1, the hot gas flowing through the bypass pipe 130 passes through the first evaporator 220 or the second via the fourth connecting pipe 219 of the connecting unit 50. It may be introduced into the evaporator 230.

The indoor unit 30 may include a plurality of evaporators 220 and 230 for evaporating a refrigerant. The plurality of evaporators 220 and 230 may include a first evaporator 220 and a second evaporator 230. During the cooling operation of the cooling system 1, the first and second evaporators 220 and 230 may evaporate the refrigerant. On the other hand, during the defrosting operation of the cooling system 1, one of the first evaporator 220 and the second evaporator 230 may be defrosted and the other may be evaporated.

The indoor unit 30 includes an evaporator inlet pipe 210 extending from the fourth connection part C4 of the connection unit 50 to the inflow side of the first and second evaporators 220 and 230. The evaporator inlet pipe 210 may be branched and connected to the first and second evaporators 220 and 230, respectively. Branch pipes connected to the first and second evaporators 220 and 230 may be referred to as "first evaporator branch pipe" and "second evaporator branch pipe", respectively.

A first evaporator expansion device 225 may be installed in the first evaporator branch pipe, and a second evaporator expansion device 235 may be installed in the second evaporator branch pipe. For example, the first evaporator expansion device 225 and the second evaporator expansion device 235 may include an electronic expansion valve (EEV) for reducing the pressure of the refrigerant.

A first evaporator fan 220a may be installed at one side of the first evaporator 220, and a second evaporator fan 230a may be installed at one side of the second evaporator 230. For example, the first and second evaporating fans 220a and 230a may be installed at a wall surface of a storage cell and blow cold air toward the storage cell.

In the indoor unit 30, a first evaporator outlet pipe 227 and a second evaporator disposed at an outlet side of the first evaporator 220 and extending to a fifth connection part C5 of the connection unit 50. The second evaporator outlet pipe 237 is disposed on the outlet side of the 230 and extends to the sixth connection part C6 of the connection unit 50.

During the cooling operation of the cooling system 1, the refrigerant evaporated in the first and second evaporators 220 and 230 may flow into the connection unit 50 through the first and second evaporator outlet pipes 227 and 237, respectively. .

On the other hand, during the defrosting operation of the cooling system 1, in particular during the defrosting operation of the first evaporator 220, the hot gas via the fourth connecting pipe 219 and the first defrosting valve 228 is discharged. After entering the first evaporator 220 through the evaporator outlet pipe 227 to perform defrosting, the second evaporator expansion device 235 may be decompressed and evaporated in the second evaporator 230. In addition, the evaporated refrigerant may flow to the sixth connection part C6 of the connection unit 50 through the second evaporator outlet pipe 237.

And, during the defrosting operation of the cooling system 1, in particular during the defrosting operation of the second evaporator 230, hot via the fourth connecting pipe 219, the connecting pipe 242 and the second defrost valve 238 Gas is introduced into the second evaporator 230 through the second evaporator outlet pipe 237 to perform defrost, and then decompressed in the first evaporator expansion device 225 and evaporated in the first evaporator 220. Can be. The evaporated refrigerant may flow to the fifth connection part C5 of the connection unit 50 through the first evaporator outlet pipe 227.

Meanwhile, during the defrosting operation of the first evaporator 220 or the second evaporator 230, at least some of the refrigerant that defrosts the evaporator is transferred to the connection unit 50 through the fourth connection part C4. It is introduced and discharged from the connection unit 50 via the first connection pipe 214. At this time, the refrigerant may be reduced in pressure while passing through the defrost expansion device 215 installed in the first connecting pipe (214).

And, the refrigerant is evaporated while passing through the outdoor heat exchanger 140 through the liquid pipe 170 of the outdoor unit 10, the evaporated refrigerant is the engine (through the flow switching valve 120 and the suction connection pipe 125) 111, the oil may be sucked into the compressor 110.

3 is a cycle diagram showing the flow of the refrigerant when performing the cooling operation of the cooling system according to the first embodiment of the present invention.

Referring to FIG. 3, when performing a cooling operation of the cooling system 1 according to the first embodiment of the present invention, the high pressure refrigerant compressed by the compressor 110 passes through the discharge pipe 114 to the flow switching valve 120. The first port 120a is introduced into and discharged through the second port 120b. In addition, the refrigerant may be introduced into the outdoor heat exchanger 140 and condensed.

The refrigerant discharged from the outdoor heat exchanger 140 may be supercooled while flowing through the liquid pipe 170 and passing through the subcooler 164. The refrigerant supercooled in the subcooler 164 may be discharged through the first service valve 175 and introduced into the connection unit 50 through the first connection part C1.

Meanwhile, the branched refrigerant passing through the subcooler 164 may be injected into the compressor 110 through the injection pipe 165.

The refrigerant introduced into the connection unit 50 may flow through the first connection pipe 214 and branch into the first and second evaporators 220 and 230 through the evaporator inlet pipe 210. At this time, since the defrost expansion device 215 is full open, the decompression expansion device 215 may not be decompressed when passing through the defrost expansion device 215.

The refrigerant branched from the evaporator inlet pipe 210 generates cold air as the refrigerant evaporates in the first and second evaporators 220 and 230, respectively, and the generated cold air is formed inside the reservoir by the first and second evaporator fans 220a and 230a. Can be supplied.

The refrigerant evaporated in the first and second evaporators 220 and 230 may flow through the first and second evaporator outlet pipes 227 and 237, respectively, and flow to the connection unit 50. In detail, the refrigerant flowing through the first evaporator outlet pipe 227 may enter the connection unit 50 through the fifth connection part C5 and pass through the first defrost valve 228. The refrigerant flowing through the second evaporator outlet pipe 237 may be introduced into the connection unit 50 through the sixth connection part C6 and may pass through the second defrost valve 238. The refrigerant passing through the third defrost valve 238 may be laminated with the refrigerant passing through the first defrost valve 228 in the third branch portion 227a of the second connection pipe 217.

The laminated refrigerant is discharged from the connection unit 50 through the second connection part C2 and flows into the outdoor unit 10 through the second service valve 255. The refrigerant introduced into the outdoor unit 10 flows through the engine 111 and may be sucked into the compressor 110 through the gas-liquid separator 105. This cycle can be repeated, and by the circulation of this refrigerant cycle, the reservoir can be efficiently cooled.

4 is a cycle diagram showing the flow of the refrigerant when the defrosting operation of the first evaporator according to the first embodiment of the present invention.

4, when the defrosting operation of the cooling system 1 according to the first embodiment of the present invention is performed, in particular, when the defrosting operation of the first evaporator 220 is performed, the high pressure refrigerant compressed by the compressor 110 is discharged. The first branch 119 of the pipe 114 may flow into the bypass pipe 130. At this time, since the first port 120a and the fourth port 120d of the flow switching valve 120 are controlled to communicate with each other, and the fourth port 120d is blocked, the refrigerant in the discharge pipe 114 is blocked. Is introduced into the flow switching valve 120 through the first port (120a) can be limited.

The refrigerant flowing through the bypass pipe 130 is discharged from the outdoor unit 10 through the third service valve 176 and flows into the connection unit 50 through the third connection part C3. The refrigerant flowing into the connection unit 50 flows through the fourth connection pipe 219 to pass through the first defrost valve 228 and to the first evaporator 220 through the first evaporator outlet pipe 227. Can be introduced. At this time, since one port of the third defrost valve 238 to which the connection pipe 242 is connected is closed, flow of the refrigerant to the connection pipe 242 may be restricted.

The refrigerant flowing into the first evaporator 220 may form a high pressure hot gas. Therefore, while the hot gas refrigerant passes through the first evaporator 220, the first evaporator 220 may be defrosted and the refrigerant may be condensed. At least some of the refrigerant having passed through the first evaporator 220 may be reduced in the second evaporator expansion device 235 and may be evaporated in the second evaporator 230. At this time, since the first evaporator expansion device 225 is full open, the refrigerant may not be depressurized in the process of passing through the first evaporator expansion device 225.

Cold air is generated in the process of evaporating the refrigerant in the second evaporator 230, and the generated cold air may be supplied to the internal space of the storage room by the driving of the second evaporating fan 230a. As described above, since the second evaporator 230 may perform a cooling operation in the process of defrosting the first evaporator 220, it is possible to prevent a phenomenon in which the internal temperature of the reservoir rises rapidly.

The refrigerant evaporated in the second evaporator 230 passes through the second defrost valve 238 via the second evaporator outlet pipe 237 and is discharged from the connection unit 50 through the second connection part C2. . The refrigerant discharged from the connection unit 50 may flow into the outdoor unit 10 through the second service valve 255 to flow the engine 111. The refrigerant may be sucked into the compressor 110 through the gas-liquid separator 105.

Meanwhile, some of the refrigerant defrosting the first evaporator 220 may flow into the connection unit 50 through the fourth connection part C4 and may flow the first connection pipe 214. That is, some of the refrigerant passing through the first evaporator 220 may flow into the second evaporator expansion device 235, and the remaining refrigerant may flow to the fourth connection part C4. At this time, the refrigerant may be reduced in pressure while passing through the defrost expansion device (215).

The refrigerant depressurized by the defrost expansion device 215 may be discharged from the connection unit 50 through the first connection part C1 and introduced into the outdoor unit 10 through the first service valve 175. In addition, the refrigerant flows through the liquid pipe 170 and may flow into the outdoor heat exchanger 140 through the subcooler 164. At this time, since the supercooled expansion device 167 is closed, the refrigerant flowing through the injection pipe 165 may be limited.

The refrigerant introduced into the outdoor heat exchanger 140 may be evaporated through heat exchange with the outside air. That is, the outdoor heat exchanger 140 acts as an evaporator, and in this process, the refrigerant may endotherm from the outside air, and thus the cooling system 1 may secure an amount of heat necessary for defrosting from an external heat source.

The refrigerant evaporated in the outdoor heat exchanger 140 flows into the flow switching valve 120 through the second port 120b and is discharged through the third port 120c. The refrigerant discharged from the flow switching valve 120 may be introduced into the suction connection pipe 125 and may be laminated with the refrigerant flowing through the engine 111 in the second branch 113.

In addition, the laminated refrigerant may be sucked into the compressor 110 via the gas-liquid separator 105. This cycle can be repeated, and by the circulation of this refrigerant cycle, the defrosting operation of some evaporators and the cooling operation of the reservoir can be performed simultaneously or continuously.

5 is a cycle diagram showing the flow of the refrigerant when the defrosting operation of the second evaporator according to the first embodiment of the present invention.

5, when the defrosting operation of the cooling system 1 according to the first embodiment of the present invention is performed, in particular, when the defrosting operation of the second evaporator 230 is performed, the refrigerant flow in the outdoor unit 10 is shown in FIG. 4. The same as described above, there is a difference in the refrigerant flow in the indoor unit 30 and the connection unit 50. Therefore, for the same parts as in FIG. 4, the description of FIG. 4 is used, and a description will be given focusing on the parts that differ from FIG. 4.

The refrigerant compressed by the compressor 110 flows from the first branch 119 of the discharge pipe 114 to the bypass pipe 130 and flows into the connection unit 50 through the third connection part C3. Can be.

The refrigerant flowing into the connection unit 50 flows through the fourth connection pipe 219, and flows into the connection pipe 242 from the fourth branch 219a and passes through the second defrost valve 238. At this time, since one port of the first defrost valve 228 to which the fourth connection pipe 219 is connected is closed, the refrigerant may be restricted from flowing into the first defrost valve 228.

The refrigerant discharged from the second defrost valve 238 may flow into the second evaporator 230 to perform defrost of the second evaporator 230. At least some of the refrigerant having passed through the second evaporator 230 may be depressurized by the first evaporator expansion device 225 and may be evaporated by the first evaporator 220. At this time, since the second evaporator expansion device 235 is full open, the second evaporator expansion device 235 may not be depressurized while passing through the second evaporator expansion device 235.

Cold air is generated in the process of evaporating the refrigerant in the first evaporator 220, and the generated cold air may be supplied to the internal space of the storage room by the driving of the first evaporating fan 220a. As described above, since the first evaporator 220 may perform a cooling operation in the process of defrosting the second evaporator 230, a phenomenon in which the internal temperature of the reservoir rises rapidly may be prevented.

The refrigerant evaporated in the first evaporator 220 passes through the first defrost valve 228 via the first evaporator outlet pipe 227 and is discharged from the connection unit 50 through the second connection part C2. . The refrigerant discharged from the connection unit 50 may flow into the outdoor unit 10 through the second service valve 255, flow the engine 111, and be sucked toward the compressor 110.

Meanwhile, some of the refrigerant defrosting the second evaporator 230 flows into the connection unit 50 through the fourth connection part C4 and flows through the first connection pipe 214. That is, some of the refrigerant passing through the second evaporator 230 flows into the first evaporator expansion device 225, and the remaining refrigerant may flow to the fourth connection part C4.

The refrigerant may be decompressed while passing through the defrosting expansion device 215 in the process of flowing the first connection pipe 214, and may flow into the outdoor unit 10 through the first service valve 175. The refrigerant introduced into the outdoor unit 10 flows through the liquid pipe 170 and may be introduced into the outdoor heat exchanger 140 through the subcooler 164. At this time, since the supercooled expansion device 167 is closed, the refrigerant flowing through the injection pipe 165 may be limited.

The refrigerant introduced into the outdoor heat exchanger 140 may be evaporated through heat exchange with the outside air. That is, the outdoor heat exchanger 140 acts as an evaporator, and in this process, the refrigerant may endotherm from the outside air, and thus the cooling system 1 may secure an amount of heat necessary for defrosting from an external heat source.

The refrigerant evaporated in the outdoor heat exchanger 140 flows into the flow switching valve 120 through the second port 120b and is discharged through the third port 120c. The refrigerant discharged from the flow switching valve 120 may be introduced into the suction connection pipe 125 and may be laminated with the refrigerant flowing through the engine 111 in the second branch 113.

In addition, the laminated refrigerant may be sucked into the compressor 110 via the gas-liquid separator 105. This cycle can be repeated, and by the circulation of this refrigerant cycle, the defrosting operation of some evaporators and the cooling operation of the reservoir can be performed simultaneously or continuously.

Hereinafter, a second embodiment of the present invention will be described. Since the present embodiment differs only in some configurations compared to the first embodiment, the differences are mainly described. For the same parts as the first embodiment, the description of the first embodiment and reference numerals are used.

6 is a cycle diagram showing a configuration of a cooling system according to a second embodiment of the present invention.

Referring to FIG. 6, the cooling system 1a according to the second embodiment of the present invention includes an outdoor expansion device 173 installed in the liquid pipe 170. The outdoor expansion device 173 may be understood as a configuration that performs a function similar to the defrosting expansion device 215 described in the first embodiment.

That is, the outdoor expansion device 173 is a refrigerant flowing through the liquid pipe 170, that is, a refrigerant that performs defrost with respect to one of the first and second evaporators 220 and 230 when defrosting the cooling system 1a. It can be understood as a device for depressurizing (condensed state). For example, the outdoor expansion device 173 may include an electronic expansion valve (EEV).

In summary, the present embodiment is characterized in that the defrosting expansion device 215 provided in the connection unit 50 of the first embodiment moves to the outdoor unit 10 to perform a similar function.

In the first and second embodiments, the first connection pipe 214 and the liquid pipe 170 may be referred to as "outdoor heat exchanger guide pipe" in that the refrigerant defrosting one evaporator is guided to the outdoor heat exchanger 140. Can be. The defrosting device 215 of the first embodiment or the outdoor expansion device 173 of the second embodiment decompresses the refrigerant flowing through the outdoor heat exchanger guide pipe to help the outdoor heat exchanger 140 to evaporate. Notes have something in common in terms of configuration.

According to the present exemplary embodiment, since the outdoor expansion device 173 is installed in the outdoor unit 10, the refrigerant condensed in the connection unit 50 may be introduced into the outdoor unit 10 to be phase-changed. The configuration can be made relatively simple.

1: cooling system 10: outdoor unit
30: indoor unit 50: connection unit
110 compressor 120 flow switching valve
125: suction connector 130: bypass piping
140: outdoor heat exchanger 214: first connector
215: defrost expansion device 219: fourth connector
220: first evaporator 228: first defrost valve
230: second evaporator 238: second defrost valve
242: connection piping

Claims (12)

A compressor for compressing the refrigerant;
A discharge pipe that guides the flow of the refrigerant passing through the compressor and has a first branch;
A flow control valve connected to the discharge pipe;
An outdoor heat exchanger disposed at an outlet side of the flow control valve;
A bypass pipe extending from the first branch of the discharge pipe and guiding a refrigerant to bypass the outdoor heat exchanger;
A suction connection pipe extending from the flow control valve and guiding the refrigerant passing through the outdoor heat exchanger to the suction side of the compressor;
A first evaporator through which a refrigerant flowing through the bypass pipe is introduced to perform defrosting; And
And a second evaporator disposed at an outlet side of the first evaporator and configured to evaporate the refrigerant passing through the first evaporator. The method of claim 1,
A connecting pipe connected to the bypass pipe; And
Further comprising a first defrost valve coupled to the connecting pipe,
And a refrigerant flowing through the bypass pipe is introduced into the first evaporator via the connection pipe and the first defrost valve. The method of claim 2,
And a first evaporator discharge pipe extending from the first defrost valve to the first evaporator. The method of claim 2,
A connection pipe branched from the connection pipe; And
And a second defrost valve coupled to the connection pipe. The method of claim 4, wherein
And a second evaporator discharge pipe extending from the second defrost valve to the second evaporator. The method of claim 1,
And a liquid pipe disposed at an outlet side of the outdoor heat exchanger and configured to flow a refrigerant condensed in the outdoor heat exchanger. The method of claim 6,
A first connection pipe connected to the liquid pipe and having a defrost expansion device installed to decompress the refrigerant; And
And an evaporator inlet pipe connected to the first connection pipe and introducing refrigerant into the first evaporator or the second evaporator. The method of claim 6,
The liquid pipe, the cooling system of the cold reservoir further comprises an outdoor expansion device for decompression of the refrigerant. The method of claim 1,
And a valve connection pipe extending from the flow switching valve to the outdoor heat exchanger. The method of claim 9,
The flow switching valve, the cold storage system of a cold storage containing a four sides. The method of claim 10,
On all sides,
A first port coupled to the discharge pipe;
A second port coupled to the valve connecting pipe; And
And a third port coupled to said suction connector. The method of claim 1,
It further includes an outdoor unit in which the compressor and the outdoor heat exchanger are installed, and an indoor unit in which the first and second evaporators are installed.
And a connection unit disposed between the outdoor unit and the indoor unit, and further comprising a connection unit connected to the outdoor unit by three pipes and connected to the indoor unit by three pipes.

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