WO2019245096A1 - Complex cooling system capable of efficient defrosting operation - Google Patents

Abstract

The present invention provides a complex cooling system whereby, when a defrosting operation of an evaporator is necessary, a liquid refrigerant is not directly evaporated, but a residual liquid refrigerant of the evaporator requiring the defrosting operation is recovered using a gas-liquid separator, or the residual liquid refrigerant of the evaporator requiring the defrosting operation is discharged to another evaporator, and thus time and costs consumed for the defrosting operation may be minimized.

Description

Complex cooling system for efficient defrosting

The present invention relates to a cooling system for cooling a distribution warehouse for refrigeration and cold storage, and more particularly, to a complex cooling system capable of efficiently performing a defrosting operation.

A defrosting operation of a general warehouse storage system for a freezer and cold storage warehouse will be described with reference to FIG. 1.

The gas-liquid separator 10 stores a refrigerant in a gaseous state at an upper portion thereof and a liquid refrigerant in an inner lower portion thereof.

The gas-liquid separator 10 is connected to the evaporator 20 and the condenser 30, respectively.

The evaporator 20 receives the liquid refrigerant in the liquid state of the gas-liquid separator 10 and evaporates it to a gas state, and then recovers the gas-liquid separator 10.

To this end, the evaporator 20 supplies a liquid refrigerant to the evaporator 21 including the evaporator tube 21a and the blower 21b and the vaporizer 21 from the gas-liquid separator 10 to the evaporator tube 21a of the evaporator 21. Gas-liquid gaseous refrigerant in a gaseous state in which the liquid refrigerant is evaporated from the liquid refrigerant supply pipe 22, the liquid refrigerant supply pump 22a provided in the liquid refrigerant supply pipe 22, and the evaporator 21a of the evaporator 21. It comprises a gas refrigerant recovery pipe 23 for recovery to the separator (10).

On the other hand, the liquid refrigerant supply pipe 22 is provided with an on-off valve 22b for blocking the supply of the refrigerant to the evaporator 21.

In addition, the condensation unit 30 receives the refrigerant in the gaseous state of the gas-liquid separator 10 to condense it into a liquid state and recovers the gas-liquid separator 10.

In the present embodiment, the condenser 30 includes a condenser 31 in the form of various heat exchangers, a gas refrigerant supply pipe 32 for supplying a gaseous refrigerant from the gas-liquid separator 10 to the condenser 31, and a condenser. And a liquid refrigerant recovery pipe 33 for recovering the liquid refrigerant in the liquid state in which the gaseous refrigerant is condensed in the gas-liquid separator 10 at 31.

The condenser 30 may compress the low-pressure gas refrigerant into a high-pressure gas refrigerant by a compressor and then condense it, or may directly condense the gas refrigerant into the liquid refrigerant without a compression process.

On the other hand, on the surface of the evaporator 21 of the evaporator 21, a dropping phenomenon occurs in which frost or ice occurs during the evaporation of the liquid refrigerant, and the defrosting operation is intermittently performed to remove the dropping to increase the evaporation efficiency or cooling efficiency. need.

To this end, defrosting means are provided in the evaporator 21.

In the present embodiment, the defrosting means includes a defrost water storage tank 41 in which defrost water is stored, and a defrost water sprinkling pipe 21c provided on an upper portion of the evaporator 21 to spray defrost water on the surface of the evaporation pipe 21a. ), A defrost water supply pipe 42 for supplying defrost water from the defrost water storage tank 41 to the defrost water sprinkling pipe 21c, a defrost water supply pump 42a provided in the defrost water supply pipe 42, It includes a defrost water recovery pipe 43 for recovering defrost water collected in the defrost water sprinkling pipe 21c and collected in the evaporator 21 to the defrost water storage tank 41.

Defrosting means, in addition to such a water spray, a variety of ways are widely known.

The detailed defrosting operation of the warehouse cooling system for refrigeration and cold storage will be described.

Normal defrosting is carried out once or twice a day.

First, the drive of the liquid refrigerant transfer pump 22a is stopped for the defrosting operation, and the liquid refrigerant supply to the evaporation tube 21a is stopped while the opening / closing valve 22b is closed.

However, even when the supply of the liquid refrigerant is stopped, the liquid refrigerant still remains in the evaporator 21a, and the blower 21b of the evaporator 21 is driven to vaporize the liquid refrigerant remaining in the evaporator 21a. .

After all of the liquid refrigerant remaining in the evaporation tube 21a is evaporated by driving the blower 21b, the defrosting water supply pump 42a is driven to start the defrosting operation.

In the defrosting operation, the most time is taken for evaporation of the liquid refrigerant remaining in the evaporation tube 21a. That is, it takes more time to prepare for the defrosting operation than the direct defrosting time. In addition, as the blower 21b is driven for such a long time, power is wasted.

In addition, since the defrosting operation takes a considerable time, that is, the warehouse cooling system is deactivated, there is a problem that the internal temperature of the refrigeration and refrigerated warehouse, etc. is difficult to have constant temperature.

The present invention has been made in order to solve the problems of the prior art as described above, when the defrosting operation of the evaporator is required to recover the remaining liquid refrigerant of the evaporator defrosting operation to the gas-liquid separator, without directly evaporating the liquid refrigerant, or defrosting operation The remaining liquid refrigerant of this evaporator is discharged to another evaporator to provide a combined cooling system that can minimize the time and expense of defrosting operation.

In order to solve the above problems, the present invention is a gas-liquid separator in which a gaseous refrigerant is stored in the upper part of the inside and a liquid refrigerant is stored in the lower part of the inside, and a liquid refrigerant of the gas-liquid separator is supplied and evaporated in the gaseous state. A first evaporation unit to recover the gas-liquid separator, a second evaporation unit to receive the liquid refrigerant of the gas-liquid separator, evaporate to a gaseous state, and to recover the gas-liquid separator, and a gaseous state of the gas-liquid separator. In a cooling system comprising a condensation unit for receiving a refrigerant to condense to a liquid state and then recovered to the gas-liquid separator:

The first evaporator includes: a first liquid refrigerant supply pipe having one end communicating with a lower portion of the gas liquid separator and the other end extending upward of the gas liquid separator; a liquid refrigerant transfer pump provided at the first liquid refrigerant supply pipe; A first gas refrigerant recovery tube communicating with an upper portion of the gas-liquid separator and extending from the other end to the upper side of the gas-liquid separator, and a first evaporation tube and a first blower, are disposed at a higher position than the gas-liquid separator. In order to connect a plurality of first evaporator, first defrosting means for removing frost or ice generated on the surface of the first evaporation pipe, and the upper end of the first evaporation pipe and the first gas refrigerant recovery pipe The first evaporation pipe for the first evaporation pipe provided for each of the first evaporation pipe gas refrigerant outlet pipe, and the lower end of the first evaporation pipe and the first liquid refrigerant supply pipe The liquid eluent inlet pipe for the first evaporator tube, the opening and closing valve for the first evaporator tube provided for each of the liquid refrigerant inlet pipe for the first evaporator tube, and the upper end between the opening and closing valve for the first evaporator tube and the first evaporator tube A first defrost refrigerant discharge pipe connected to the first liquid refrigerant inflow pipe for the first evaporation pipe and provided at each of the first liquid refrigerant inflow pipes for the first evaporation pipe so that a lower end thereof is connected to the first gas refrigerant recovery pipe; It comprises a first refrigerant discharge opening and closing valve provided for each;

The second evaporator includes a second liquid refrigerant supply pipe having one end communicating with a lower portion of the gas-liquid separator and the other end extending downward of the gas-liquid separator, and one end communicating with an upper portion of the gas-liquid separator and the other end of the gas-liquid separator. A plurality of second evaporators including a second gas refrigerant recovery tube extending downward, a second evaporator tube and a second blower and disposed at a lower position than the gas-liquid separator, and a surface of the second evaporator tube. Second defrosting means for removing frost or ice generated, and a gas refrigerant outlet pipe for the second evaporation pipe provided for each of the second evaporation pipe to connect the upper end of the second evaporation pipe and the second gas refrigerant recovery pipe. And a liquid refrigerant inflow pipe for the second evaporation pipe provided for each of the second evaporation pipes so as to connect the lower end of the second evaporation pipe and the second liquid refrigerant supply pipe with each other, and the second evaporation pipe. On and off valves for the second evaporation tube provided for each liquid refrigerant inlet pipe, and the upper end is connected to the liquid refrigerant inlet pipe for the second evaporation pipe between the on-off valve for the second evaporation pipe and the second evaporation pipe, the lower end of the second evaporation At least one second defrost refrigerant discharge pipe connected to the second refrigerant pipe opening and closing valve for the second evaporation pipe connected to the second evaporation pipe disposed in the lower position than the second evaporation pipe and the liquid refrigerant inlet pipe for the second evaporation pipe And a second refrigerant discharge opening / closing valve provided for each of the second defrost refrigerant discharge tubes; It is characterized by.

As described above, when the defrosting operation of the evaporator is required, the liquid refrigerant is recovered to the gas-liquid separator without directly evaporating the liquid refrigerant, or the remaining liquid refrigerant of the evaporator requiring defrosting operation is discharged to another evaporator. Minimize time and expense.

Furthermore, the present invention can increase the constant temperature of the internal temperature of the refrigerator and the cold storage warehouse by minimizing the downtime of the warehouse cooling system according to the defrosting operation.

1 is a conceptual diagram of a warehouse cooling system for a frozen and refrigerated warehouse according to the prior art,

2 is a conceptual diagram of a distribution warehouse cooling system for a freezer and cold storage according to an embodiment of the present invention;

3 is a flow chart of a refrigerant during defrosting operation in FIG. 2.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted for simplicity of explanation, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

2 is a conceptual diagram of a distribution warehouse cooling system for a freezer and cold storage warehouse according to an embodiment of the present invention, and FIG. 3 is a flowchart of a refrigerant during defrosting operation in FIG. 2.

2 and 3 illustrate the height of the gas-liquid separator and the plurality of evaporators are installed.

The gas-liquid separator 110 stores a refrigerant in a gaseous state at an upper portion thereof and a liquid refrigerant in an inner lower portion thereof.

The gas-liquid separator 110 is connected to the first evaporator 120, the second evaporator 130, and the condenser 140, respectively.

The first evaporator 120 and the second evaporator 130 are intended to recover the gas-liquid separator 110 after being evaporated in a gaseous state by receiving a liquid refrigerant in the gas-liquid separator 110.

The condensation unit 140 receives the gaseous refrigerant of the gas-liquid separator 110 to condense it into a liquid state and recovers the gas-liquid separator 110.

A detailed configuration of the first evaporator 120 will be described.

The first evaporator 120 includes a first liquid refrigerant supply pipe 121, a liquid refrigerant transfer pump 121a, a first gas refrigerant recovery pipe 122, and a plurality of first evaporators 123-1 to 3. And a plurality of first gaseous coolant outlet pipes 124 for the first evaporation pipe, a plurality of first liquid evaporation pipe inlets 125 for the first evaporation pipe, a plurality of open / close valves 125a for the first evaporation pipe, and a plurality of first evaporation pipes. The pipe flow control valve 125b, a plurality of first defrost refrigerant discharge tubes 126, and a plurality of first refrigerant discharge open / close valves 126a are included.

The first liquid refrigerant supply pipe 121 has a form in which one end communicates with the lower portion of the gas-liquid separator 110 and the other end extends upwardly of the gas-liquid separator 110. A liquid refrigerant transfer pump 121a is provided in the first liquid refrigerant supply pipe 121 to forcibly circulate the liquid refrigerant of the gas-liquid separator 110. That is, the first evaporator 120 is a liquid pump type cooling system that requires a separate forced conveying means such as a pump for supplying a liquid refrigerant.

A first gas refrigerant recovery pipe 122 is provided to correspond to the first liquid refrigerant supply pipe 121, and one end of the first gas refrigerant recovery pipe 122 communicates with an upper portion of the gas liquid separator 110, and the other end thereof is a gas liquid separator. It is a form extended toward the upper direction of the (110).

A plurality of first evaporators 123-1, 123-2, and 123-3 connected to the first liquid refrigerant supply pipe 121 and the first gas refrigerant recovery pipe 122 are provided.

In the present embodiment, the first evaporators 123-2 and 123-3 are disposed at a position higher than the gas-liquid separator 110, and the first evaporators 123-1 are disposed at the same height as the gas-liquid separator 110.

Each of the first evaporators 123-1, 123-2, and 123-3 forcibly supplies air to the surfaces of the first evaporation tube 123a and the first evaporation tube 123a where the liquid refrigerant is evaporated into the gaseous refrigerant. It comprises a first blower (123b). Each of the first evaporators 123-1, 123-2, and 123-3 is provided in a freezer and a refrigerated warehouse to maintain a high temperature in the high temperature.

In addition, each of the first evaporators (123-1, 123-2, 123-3) is provided with a first defrosting means (not shown) for removing frost or ice generated on the surface of the first evaporation pipe (123a).

As the first defrosting means, various methods known in the art, such as a watering method and a heater method, may be adopted.

The first evaporator 123a of each of the first evaporators 123-1, 123-2, and 123-3 has an upper end thereof recovered through the gas refrigerant outlet pipe 124 for the first evaporator. It is connected to the pipe 122, the lower end is connected to the first liquid refrigerant supply pipe 121 through the liquid refrigerant inlet pipe 125 for the first evaporation pipe.

That is, the first evaporator 123a of each of the first evaporators 123-1, 123-2, and 123-3 is a gas refrigerant outlet pipe 124 for the first evaporator and a liquid refrigerant inlet pipe 125 for the first evaporator. )

Each of the first refrigerant evaporating pipe liquid refrigerant inlet pipe 125 is provided with a first evaporating tube opening and closing valve 125a and a first evaporating pipe flow control valve 125b.

Each of the first evaporator flow rate control valve 125b serves to adjust an appropriate amount of liquid refrigerant into the first evaporator 123a of each of the first evaporators 123-1, 123-2, and 123-3. After setting to a predetermined flow rate at the time of initial installation, the refrigerant flows at a preset flow rate during normal operation.

The first defrosting refrigerant discharge pipe 126 is provided for each of the liquid refrigerant inflow pipes 125 for the first evaporation pipes connected to the first evaporators 123-2 and 123-3 disposed at a position higher than the gas-liquid separator 110. Connected.

The first refrigerant refrigerant discharge pipe for defrosting is not provided in the liquid refrigerant inlet pipe 125 for the first evaporator pipe connected to the first evaporator 123-1 disposed at the same height as the gas-liquid separator 110.

The first defrosting refrigerant discharge pipe 126 has an upper end connected to the liquid refrigerant inlet pipe 125 for the first evaporation pipe between the on-off valve 125a for the first evaporation pipe and the first evaporation pipe 123a, and the lower end of the first defrost refrigerant discharge pipe 126. It is connected to the one gas refrigerant recovery pipe 122.

In addition, a first refrigerant discharge opening / closing valve 126a is provided for each of the first defrost refrigerant discharge tubes 126.

Meanwhile, the first liquid refrigerant supply pipe 121 and the first gas refrigerant recovery pipe 122 are connected to each other by a bypass pipe portion, and the first liquid refrigerant supply pipe 121 is connected to the first liquid refrigerant supply pipe 121 in the first liquid refrigerant supply pipe 121. The liquid refrigerant bypass flow rate adjusting unit is provided to adjust the flow rate of the liquid refrigerant bypassed to the gas refrigerant recovery pipe 122.

In the present exemplary embodiment, the plurality of bypass pipes 127-2 and 127-3 having one end connected to the first liquid refrigerant supply pipe 121 and the other end connected to the first gas refrigerant recovery pipe 122. The liquid refrigerant bypass flow rate adjusting unit is a bypass opening / closing valve 127a provided for each of the plurality of bypass pipes 127-2 and 127-3.

The bypass opening / closing valve 127a provided for each of the plurality of bypass pipes 127-2 and 127-3 is provided for each of the first evaporation pipes 123a of the plurality of first evaporators 123-2 and 123-3. It operates in response to the operation of the opening / closing valve 125a for the first evaporation pipe. In the present embodiment, two bypass opening / closing valves 127a are provided corresponding to the two first evaporators 123-2 and 123-3.

Hereinafter, a detailed configuration of the second evaporator 130 will be described.

The second evaporator 130 includes a second liquid refrigerant supply pipe 131, a second gas refrigerant recovery pipe 132, a plurality of second evaporators 133-1 to 2, and a plurality of gases for the second evaporation pipe. A coolant outlet pipe 134, a plurality of liquid coolant inlet pipes 135 for the second evaporation pipe, a plurality of open / close valves 135a for the second evaporation pipe, a plurality of flow control valves 135b for the second evaporation pipe, At least one second defrost refrigerant discharge pipe 136 and at least one second refrigerant discharge opening and closing valve 136a.

One end of the second liquid refrigerant supply pipe 131 communicates with the lower part of the gas-liquid separator 110, and the other end thereof extends downwardly of the gas-liquid separator 110. Therefore, the liquid refrigerant stored in the gas-liquid separator 110 flows downward along the second liquid refrigerant supply pipe 131 by gravity (water head or siphon phenomenon). That is, the second evaporation unit 130 is a siphonic cooling system that does not require a separate forcible transfer means such as a pump for supplying the liquid refrigerant.

The second gas refrigerant recovery pipe 132 is provided to correspond to the second liquid refrigerant supply pipe 131, and one end of the second gas refrigerant recovery pipe 132 communicates with the upper portion of the gas liquid separator 110, and the other end thereof is the gas liquid separator. It extends toward the bottom of the (110). In this embodiment, one end of the second gas coolant recovery pipe 132 is branched from one end of the first gas coolant recovery pipe 132, but this is a conventional technique that can be appropriately designed by a person skilled in the art.

A plurality of second evaporators 133-1 and 133-2 connected to the second liquid refrigerant supply pipe 131 and the second gas refrigerant recovery pipe 132 are provided.

In the present embodiment, each of the second evaporators 133-1 and 133-2 is disposed at a lower position than the gas-liquid separator 110. This is to allow the liquid refrigerant of the gas-liquid separator 110 to be supplied to each of the second evaporators 133-1 and 133-2 via the second liquid refrigerant supply pipe 131.

In the present embodiment, as shown in FIG. 2, each of the second evaporators 133-1 and 133-2 is located at different heights, and the second evaporator 133-1 is positioned at the lowest position. 133-2) is shown to be located at the highest position.

Each of the second evaporators 133-1 and 133-2 forcibly supplies air to the surfaces of the second evaporation tube 133a and the second evaporation tube 133a where the liquid refrigerant is evaporated into the gaseous refrigerant. 133b. Each of these second evaporators (133-1, 133-2) is provided in the refrigeration and refrigerated warehouse to keep the temperature in the high temperature at low temperatures.

In addition, each of the second evaporators 133-1 and 133-2 is provided with a second defrosting means (not shown) for removing frost or ice generated on the surface of the second evaporation pipe 133a.

The second defrosting means is substantially the same as the first defrosting means, only with a different name.

The second evaporation pipe 133a of each of the second evaporators 133-1 and 133-2 has a second gas refrigerant recovery pipe 132 having an upper end thereof via a gas coolant outlet pipe 134 for the second evaporation pipe. The lower end is connected to the second liquid refrigerant supply pipe 131 through the liquid refrigerant inlet pipe 135 for the second evaporation pipe.

That is, the second evaporation pipe 133a of each of the second evaporators 133-1 and 133-2 is connected to the gas refrigerant outlet pipe 134 for the second evaporation pipe and the liquid refrigerant inlet pipe 135 for the second evaporation pipe. .

Each of the second refrigerant pipe liquid refrigerant inlet pipe 135 is provided with an opening and closing valve 135a for the second evaporation pipe and a flow control valve 135b for the second evaporation pipe.

Each of the second evaporation pipe flow control valve 135b serves to adjust an amount of liquid refrigerant into the second evaporation pipe 133a of each of the second evaporators 133-1 and 133-2. After the predetermined flow rate is set at the time of installation, the refrigerant flows at the preset flow rate during normal operation.

The second defrosting refrigerant discharge pipe 136 is provided in the liquid refrigerant inlet pipe 135 for the second evaporation tube corresponding to the second evaporator 133-2.

In addition, the liquid refrigerant inlet pipe 135 for the second evaporator tube corresponding to the second evaporator 133-1 positioned at the lowest position does not have a defrost refrigerant discharge tube.

Each of the second defrost refrigerant discharge tubes 136 has an upper end connected to the liquid refrigerant inlet tube 135 for the second evaporation tube corresponding to the second evaporation tube while the lower end thereof is disposed at a lower position than the second evaporation tube. It is connected to the liquid refrigerant inlet pipe 135 for the second evaporation pipe connected to another second evaporation pipe.

That is, the second defrosting refrigerant discharge pipe 136 provided in correspondence with the second evaporator 133-2 has an upper end portion corresponding to the second evaporator 133-2, and the second evaporator opening / closing valve 135a and the second It is connected to the liquid refrigerant inlet pipe 135 for the second evaporation pipe between the two evaporation pipe (133a).

In addition, the second defrosting refrigerant discharge pipe 136 provided in correspondence with the second evaporator 133-2 has a lower end portion provided in the first evaporator 133-1, the opening / closing valve 135a for the second evaporator 133-1 and the second evaporator. It is connected to the liquid refrigerant inlet pipe 135 for the second evaporation pipe between the pipes (133a).

In addition, a second refrigerant discharge opening / closing valve 136a is provided in the second defrost refrigerant discharge tube 136.

In the present embodiment, the condenser 140 includes a condenser 141 in the form of various heat exchangers, a gas refrigerant supply pipe 142 for supplying a gaseous refrigerant from the gas-liquid separator 110 to the condenser 141, and a condenser. The liquid refrigerant recovery pipe 143 for recovering the liquid refrigerant in the liquid state in which the gaseous refrigerant is condensed in the gas-liquid separator 110 is formed at 140.

In the present embodiment, the condenser 140 is configured to directly condense the gas refrigerant into the liquid refrigerant without the compression process. However, according to the embodiment, the condenser 140 compresses the low-pressure gas refrigerant into a high-pressure gas refrigerant by a compressor. It may be a way to condense it.

The operation of this embodiment will be described.

In general, the system is operated to cool the refrigeration and cold storage, etc. to a low temperature state. In this case, as shown in FIG. 2, both the first evaporating pipe open / close valve 125a and the second evaporating pipe open / close valve 135a are in an open state, and the first refrigerant discharge open / close valve 126a and the second refrigerant discharge are open. The on-off valve 136a and the bypass on-off valve 127a are all in a closed state.

Therefore, through the first evaporator 120, the liquid refrigerant is the first liquid evaporator (123-) through the first liquid refrigerant supply pipe 121 and the liquid refrigerant inlet pipe 125 for the first evaporation tube in the gas-liquid separator 110. 1, 123-2, 123-3, the first evaporation pipe (123a) is introduced into the first evaporation pipe (123a) while evaporating and cooling the inside of the refrigerated warehouse, evaporation in the first evaporation pipe (123a) The gaseous coolant is recovered to the gas-liquid separator 110 through the first gaseous coolant outlet pipe 124 and the first gas coolant recovery pipe 122.

In addition, through the second evaporator 130, the liquid refrigerant is the second liquid evaporator (133-) in the gas-liquid separator 110 through the second liquid refrigerant supply pipe 131 and the liquid refrigerant inlet pipe 135 for the second evaporation tube. 1, 133-2 to the second evaporation pipe (133a) and then evaporated in the second evaporation pipe (133a) to cool the inside of the freezer and cold storage warehouse, the gas refrigerant evaporated in the second evaporation pipe (133a) The gaseous coolant outlet pipe 134 and the second gas refrigerant recovery pipe 132 for the second evaporation pipe are recovered to the gas-liquid separator 110.

The gas refrigerant of the gas-liquid separator 110 is supplied to the condenser 141 through the gas coolant supply pipe 142 to condense into a liquid refrigerant and then recovered to the gas-liquid separator 110 through the liquid refrigerant recovery pipe 143.

In this case, as the condensation heat source of the condenser 141, various heat sources may be adopted.

Intermittent defrosting operation is necessary while maintaining this normal cooling operation.

Each evaporator performs defrosting once or twice a day.

Referring to FIG. 3, the defrosting operation of the first evaporator 123-2 of the first evaporator 120 will be described as an example.

As the opening and closing valve 125a for the first evaporator 123-2 to the first evaporator 123-2 is closed, the inflow of the liquid refrigerant to the first evaporator 123a of the first evaporator 123-2 is stopped.

In addition, the liquid refrigerant remaining in the first evaporation pipe 123a of the first evaporator 123-2 while the first refrigerant discharge opening / closing valve 126a for the first evaporator 123-2 is opened is the first evaporator 123. It is recovered to the gas-liquid separator 110 via the first defrost refrigerant discharge pipe 126 and the first gas refrigerant recovery pipe 122 for −2). By discharging the liquid refrigerant, it is not necessary to evaporate the liquid refrigerant inside the first evaporation pipe 123a of the first evaporator 123-2 for the defrosting operation.

As such, after the liquid refrigerant inside the first evaporation pipe 123a of the first evaporator 123-2 is discharged, the first evaporation pipe 123a of the first evaporator 123-2 is discharged by the first defrosting means. Defrosting operation is performed.

Therefore, the defrosting operation can be performed at a very short time and at a low cost, and it is also possible to drastically reduce the operation stop time of the evaporator 1 evaporator 123-2, thereby increasing the constant temperature of the refrigeration and cold storage warehouse.

Meanwhile, in order to prevent excess liquid refrigerant from being supplied to the other first evaporators 123-1 and 123-3 while stopping the inflow of the liquid refrigerant into the first evaporator 123a of the first evaporator 123-2. The bypass opening / closing valve 127a of the bypass pipe 127-2 corresponding to the first evaporator 123-2 is opened and is supplied to the first evaporating pipe 123a of the first evaporator 123-2 in the normal operation. The refrigerant having a flow rate corresponding to the flow rate of the refrigerant which has been used is bypassed to the first gas refrigerant recovery pipe 122 through the bypass pipe 127-2 and then recovered to the gas-liquid separator 110. Therefore, the other evaporators 123-1 and 123-3 may be supplied with the same liquid refrigerant in both normal operation and defrost operation, thereby increasing the constant temperature of the internal temperature.

When the defrosting operation is completed, the first evaporation tube open / close valve 125a is opened, and the first refrigerant discharge open / close valve 126a and the bypass open / close valve 127a are closed to perform normal operation.

However, the defrosting operation for the first evaporator 123-1 is performed by a conventional method.

Referring to FIG. 3, defrosting of the second evaporator 133-2 of the second evaporator 130 will be described as an example.

As the opening and closing valve 135a of the second evaporator 133-2 to the second evaporator 133-2 is closed, the inflow of the liquid refrigerant to the second evaporator 133a of the second evaporator 133-2 is stopped.

In addition, the liquid refrigerant remaining in the second evaporation pipe 133a of the second evaporator 133-2 while the second refrigerant discharge opening / closing valve 136a is opened for the second evaporator 133-2 is stored in the second evaporator 133. The second of the second evaporator 133-1 via the second refrigerant cooling pipe 136 for the second defrost refrigerant pipe 136 and the second liquid evaporator inlet pipe 135 for the second evaporator 133-1. It is supplied to the evaporation tube 133a and evaporated. By discharging the liquid refrigerant, it is not necessary to evaporate the liquid refrigerant inside the second evaporation pipe 133a of the second evaporator 133-2 for the defrosting operation.

As described above, after the liquid refrigerant inside the second evaporator 133a of the second evaporator 133-2 is discharged, the defrosting operation is performed on the second evaporator 133a of the second evaporator 133-2 by defrosting means. This is done.

Therefore, the defrosting operation can be performed at a very short time and at a low cost, and further, the operation stop time of the second evaporator 133-2 can be greatly reduced, thereby increasing the constant temperature of the freezer and cold storage warehouse.

When the defrosting operation is completed, the second evaporation tube open / close valve 135a is opened, and the opened second refrigerant discharge open / close valve 136a is closed to perform normal operation.

However, according to the present embodiment, the defrosting operation for the second evaporator 133-1 positioned at the lowest position should be applied in the conventional manner.

The above description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, the embodiments described above are to be understood in all respects as illustrative and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

The present invention can be used as a cooling system for cooling the distribution warehouse for refrigeration and cold storage.

Claims (1)

A gas-liquid separator in which a gaseous refrigerant is stored in the upper part and a liquid refrigerant is stored in the lower part of the inside, and a first evaporation to receive the liquid refrigerant in the gas-liquid separator and to evaporate it in a gaseous state to recover the gas-liquid separator. And a second evaporator which receives the liquid refrigerant in the gas-liquid separator and evaporates it to a gaseous state and recovers it to the gas-liquid separator, and condenses it into a liquid state by receiving the gaseous refrigerant of the gas-liquid separator. In a cooling system comprising a condensation unit to be recovered by a gas-liquid separator: The first evaporator, A first liquid refrigerant supply pipe having one end communicating with a lower portion of the gas-liquid separator and the other end extending upwardly of the gas-liquid separator; A liquid refrigerant transfer pump provided in the first liquid refrigerant supply pipe; A first gas refrigerant recovery tube having one end communicating with an upper portion of the gas-liquid separator and the other end extending upwardly of the gas-liquid separator; A plurality of first evaporators including a first evaporator and a first blower and disposed at a position higher than the gas-liquid separator; First defrosting means for removing frost or ice generated on the surface of the first evaporation pipe, A gas coolant outlet pipe for a first evaporation pipe provided for each of the first evaporation pipes so as to connect an upper end of the first evaporation pipe and the first gas refrigerant recovery pipe to each other; A liquid refrigerant inlet pipe for the first evaporation pipe provided for each of the first evaporation pipes so as to connect the lower end of the first evaporation pipe and the first liquid refrigerant supply pipe with each other; A first evaporation pipe opening / closing valve provided for each of the first refrigerant evaporating pipe liquid refrigerant inlets; The liquid refrigerant inlet pipe for the first evaporator pipe is connected to the liquid eluent inlet pipe for the first evaporator pipe between the opening and closing valve for the first evaporator pipe and the first evaporator pipe and the lower end is connected to the first gas refrigerant recovery pipe. The first defrost refrigerant discharge pipe provided for each, It comprises a first refrigerant discharge opening and closing valve provided for each of the first defrost refrigerant discharge pipe; The second evaporation unit, A second liquid refrigerant supply pipe having one end communicating with a lower portion of the gas-liquid separator and the other end extending downwardly of the gas-liquid separator; A second gas refrigerant recovery tube having one end communicating with an upper portion of the gas-liquid separator and the other end extending downwardly of the gas-liquid separator; A plurality of second evaporators including a second evaporation tube and a second blower and disposed at a lower position than the gas-liquid separator; Second defrosting means for removing frost or ice generated on the surface of the second evaporation pipe; A gas refrigerant outlet pipe for the second evaporation pipe provided for each of the second evaporation pipes so as to connect the upper end of the second evaporation pipe and the second gas refrigerant recovery pipe with each other; A liquid refrigerant inlet pipe for the second evaporation pipe provided for each of the second evaporation pipes so as to connect the lower end of the second evaporation pipe and the second liquid refrigerant supply pipe with each other; An on / off valve for a second evaporation pipe provided for each of the liquid refrigerant inflow pipes for the second evaporation pipe; The upper end is connected to the liquid refrigerant inlet pipe for the second evaporation pipe between the on-off valve for the second evaporation pipe and the second evaporation pipe and the lower end is connected to another second evaporation pipe disposed at a lower position than the second evaporation pipe. At least one second defrost refrigerant discharge pipe connected to the liquid refrigerant inlet pipe for the second evaporation pipe between the on / off valve for the second evaporation pipe and the second evaporation pipe; A second refrigerant discharge opening / closing valve provided for each of the second defrost refrigerant discharge tubes; Complex cooling system capable of efficient defrosting operation characterized in that.

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