JPH04350488A - Refrigerating plant - Google Patents

Abstract

PURPOSE:To prevent sleep of refrigerant by feeding part of refrigerant fed from a first heat exchanger to a second heat exchanger to other second heat exchanger at the time of defrosting the first exchanger. CONSTITUTION:A first heat exchanger 11 and a plurality of cooling units 18B-1-18B-n formed of second heat exchangers 5 connected in parallel with the exchanger 1 are piping-connected to a refrigerant compressor 19, one condenser 18A formed of a condenser 20. At the time of defrosting the exchanger 11 of each cooling unit, a cycle in which refrigerant is returned to the compressor 19 through the compressor 19, the condenser 20, a bypass circuit 32, an inner layer heat exchanger 11, a connecting pipe 33, a solenoid valve 37, a pressure reducing valve 29, an outer layer heat exchanger 5 and a gas/liquid separator 23, is formed. An equalizer is so connected as to feed part of the refrigerant from the arbitrary exchanger 11 to the exchanger 5 as a pair with the arbitrary exchanger to the exchanger 5 of the other cooling unit.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration system equipped with a plurality of cooling units each having a first heat exchanger and a second heat exchanger functioning as an evaporator.

0002

[Prior Art] Patent application filed earlier by the applicant in 1986-
No. 211128 describes a method of operating one low-temperature showcase, but multiple (n) low-temperature showcases are connected in parallel and operated with one condensing unit (18A). In this case, a refrigeration system usually employs the refrigerant circuit shown in FIG. When multiple units are connected, the cooling unit (18B-1) of each low temperature showcase (1)
The high pressure liquid pipe (25A) for supplying high pressure liquid refrigerant to the cooling units (18B-1) to (18B-n)
The diameter corresponds to the number of 18B-n), making it thick and long.

[0003] The defrosting method in this refrigeration system uses this high-pressure liquid pipe (25A) to transfer water from the condenser (20) to the inner layer heat exchanger (11), which is the first heat exchanger of each cooling unit. This is a method of defrosting by sending a high-pressure gas-liquid mixed refrigerant, and the condensed liquid refrigerant obtained by this defrosting is evaporated in the second heat exchanger, the outer layer heat exchanger (5), to defrost it. Also when cooling the storage room. On the other hand, the end of this defrosting can be done by using any cooling unit such as the inner layer heat exchanger (18B-n) during defrosting.
If the temperature of the condensed liquid refrigerant flowing from 11) to the outer layer heat exchanger (5) reaches, for example, the return set temperature 5°C or higher, the supply of the gas-liquid mixed refrigerant to the cooling unit (18B-n) is stopped, and this cooling is stopped. In addition to recovering the refrigerant in the unit,
The defrosting recovery of the other cooling units (18B-1) to (18B-4) will be awaited.

0004

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, for example, five or more cooling units (18B
-1) to (18B-4) are connected and operated,
In the high-pressure liquid pipe (25A) which has become thick and long as described above, the gas-liquid mixed refrigerant causes gas-liquid separation, and the cooling units (18B-2) to (1) near the condensing unit (18A) shown in FIG.
8B-n) is supplied with a gas phase refrigerant during defrosting,
Liquid refrigerants with large mass and low defrosting heat are used in condensing units (
18A) into the furthest cooling unit (18B-1). Therefore, liquid refrigerant lower than the reset setting value accumulates in the inner layer heat exchanger (11) of the cooling unit (18B-1), and its temperature does not rise easily.
A problem occurred in that defrosting recovery was extremely delayed compared to other cooling units (18B-2) to (18B-n), and the storage room temperature of the low-temperature showcase that returned first rose.

[0005]

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a first heat exchanger and a first heat exchanger for one condensing unit consisting of a refrigerant compressor and a condenser. A plurality of cooling units consisting of a second heat exchanger and a second heat exchanger connected in parallel are connected by piping, and during defrosting operation of the first heat exchanger of each cooling unit, the refrigerant is transferred from the refrigerant compressor to the condenser to the bypass. A circuit - first heat exchanger - communication pipe - pressure reducing valve - second heat exchanger - piping is connected to return to the refrigerant compressor through a gas-liquid separator, and from any first heat exchanger. A refrigeration system connected by a pressure equalizing pipe so that a part of the refrigerant reaching the second heat exchanger paired with this arbitrary first heat exchanger flows to the second heat exchanger of another cooling unit. I will provide a.

[0006]

[Function] According to the embodiment, by providing the pressure equalizing pipe (45), the first
If the liquid refrigerant in the heat exchanger (11) accumulates and so-called refrigerant stagnation tends to occur, part of the refrigerant is transferred to another cooling unit (18B-) with lower pressure through the pressure equalization pipe (45).
2) to (18B-n) flow to the second heat exchanger (5),
A cooling unit in which the liquid refrigerant in the cooling unit (18B-1) is running low, causing the temperature of the first heat exchanger (11) to rise easily, and the liquid refrigerant running out, causing the temperature inside the refrigerator to rise easily. (18B-n) second heat exchanger (5)
The refrigerant flows and is evaporated, providing a cooling effect.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below based on the drawings.

[0008] (1) shown in Fig. 2 is an open-type low-temperature showcase whose main body is composed of an insulating wall (2) with an opening (3) for storing and taking out products in the front. A heat-insulating first partition plate (4) is disposed at an appropriate distance from the inner wall of the heat-insulating wall, and includes a damper (4A) that opens toward the inner layer, which will be described later, and a window (4C) that is closed by this damper. an outer layer (7) in which a second heat exchanger (5) of plate fin type located in the back area and an outer layer blower (6) of axial flow type are arranged;
an outer layer air outlet (8) located along the upper edge of the opening; and an outer layer suction port (9) located along the lower edge of the opening and opposed to the outer layer air outlet. , and the first
A second partition plate (10) made of metal is arranged at an appropriate distance from the inner wall of the partition plate, and the plate fin is located in the back area and is located at a lower position than the second heat exchanger (5). Type 1
an inner layer (13) in which a heat exchanger (11) and an axial type inner layer blower (12) are arranged; Inner layer outlet (14
) and an inner layer suction port (
15) and a storage room (17) with multiple shelves (16).
). The damper is made of a heat insulating material, such as a plate-shaped material made of resin or a metal plate with a heat insulating sheet attached, and when opened, the tip thereof comes into contact with the outer wall of the second partition plate (10). is preferred. The second heat exchanger (5) is arranged in the outer layer (5) so as to be located downstream in the flow direction of the circulating air when viewed from the damper (4A), and the second heat exchanger (11 ) is the damper (4A)
Inner layer (13) on the upstream side in the flow direction of the circulating air when viewed from the
located within. The damper (4A) is opened and closed by a drive device consisting of a gear motor (M) equipped with a speed reduction mechanism, an elongated arm (A) that converts rotational motion of the gear motor into reciprocating linear motion, and the like.

Reference numeral (18) shown in FIG. 3 is a refrigeration system for cooling one low-temperature showcase (1), which includes a refrigerant compressor (19), a water-cooled or air-cooled condenser (20), and a receiver. A liquid container (21), a pressure reducing valve (22) consisting of an expansion valve etc. having a temperature sensing part (22A), an inner layer heat exchanger (11), a gas-liquid separator (23), and a high pressure gas pipe (24), a high pressure liquid pipe (25),
A high-pressure liquid branch pipe (28) connected in an annular manner with a first low-pressure liquid pipe (26) and a low-pressure gas pipe (27), and an inlet connected to the middle of the high-pressure liquid pipe (25), and a temperature sensing section. (29A
), a second low-pressure liquid pipe (30), and a low-pressure gas branch pipe (31) whose outlet is connected to the middle of the low-pressure gas pipe (27). A heat exchanger (5) is connected in parallel to the first heat exchanger (11). (32) transfers the high-pressure refrigerant to the first heat exchanger (11
) is a bypass circuit that leads to both the first and second bypass pipes (
32A) (32B), and the first bypass pipe (32A
) is connected to the high pressure liquid pipe (25) between the condenser (20) and the liquid receiver (21), and the outlet is connected to the high pressure liquid pipe (25) between the liquid receiver (21) and the pressure reducing valve (22). In between, it is connected to the liquid receiver (21) in the high pressure liquid pipe (25), and the second bypass pipe (
The high-pressure liquid pipe (25) is connected between the liquid receiver (21) and the pressure reducing valve (22) so that the inlet of the liquid pipe (32B) is located downstream in the flow direction of the refrigerant from the outlet of the first bypass pipe (32A). The outlet is connected to the middle of the first low pressure liquid pipe (26). The outlet of the first bypass pipe (32A) and the outlet of the second bypass pipe (32B) are connected to a high pressure liquid pipe (
25), a part of this high-pressure liquid pipe becomes a shared pipe line (25A) and constitutes a part of the bypass circuit (32). When a plurality of low-temperature showcases (1) are connected, the length of the common pipe line (25A) and the low-pressure gas pipe (27) ranges from several meters to several tens of meters. (33) is a connecting pipe that guides the high-pressure liquid refrigerant of the first heat exchanger to the second heat exchanger (5) during the defrosting operation of the first heat exchanger (11), and its inlet is It is connected to the low pressure gas pipe (27) between the first heat exchanger (11) and the gas-liquid separator (23), and the outlet is connected to the high pressure liquid branch pipe (27).
8) is connected in the middle. (34) to (39) are opened and closed as necessary to switch the flow path of the circulating refrigerant.
to sixth solenoid valves. The first solenoid valve (34) is a high pressure liquid pipe (
25) during the cooling operation of the first heat exchanger (11) and both the first and second heat exchangers (11) (5).
The first heat exchanger (11
) is blocked during defrosting operation and pump down operation. Further, the second electromagnetic valve (35) is connected to a low pressure gas pipe (
27), and its opening/closing operation is the same as that of the first solenoid valve (34). Further, the third solenoid valve (36
) is provided in the second bypass pipe (32B), and is opened by a controller described later only during defrosting operation of the first heat exchanger (11). is closed by a temperature switch (36A) that detects the refrigerant temperature at the outlet of the refrigerant. Further, the fourth solenoid valve (37) is connected to the connecting pipe (3
3) and the pressure reducing valve (29).
8) and is opened only during cooling operation of the first heat exchanger (11). Further, the fifth solenoid valve (
38) is provided in the first bypass pipe (32A), and its opening/closing operation is the same as that of the third solenoid valve (36), and is opened only during defrosting operation of the first heat exchanger (11). Ru. Further, the sixth solenoid valve (39) is provided in the high-pressure liquid pipe (25) between the liquid receiver (21) and the common pipe line (25A), and its opening/closing operation is controlled by the first, 2nd double solenoid valve (34)
This is the same as (35). (40) is a check valve installed in the high-pressure liquid pipe (25) between the inlet of the first bypass pipe (32A) and the liquid receiver (21), and
During the defrosting operation of 1), the refrigerant stored in the receiver (21) is prevented from flowing back toward the inlet of the first bypass pipe (32A) due to the ejector effect of the high-pressure refrigerant flowing through the bypass circuit (32). . (41) is the connecting pipe (33)
During the cooling operation of the first heat exchanger (11) and both the first and second heat exchangers (11) (5),
The high pressure liquid refrigerant passing through the high pressure liquid pipe (25) or the high pressure liquid branch pipe (28) is transferred from the communication pipe (33) to the low pressure gas pipe (27).
prevent it from flowing.

The refrigeration system (18) is constructed as described above, and the part indicated by the chain line (18A) in FIGS. 3 to 6 is the condensation unit installed in the machine room of the store,
Since the part indicated by 8B) is divided into cooling units installed inside the store, if multiple low-temperature showcases (1) are connected together as shown in Figure 1, the part indicated by 8B) can be used as a shared cooling unit to connect both units. Pipe line (25A) and low pressure gas pipe (
27) can be several tens of meters long depending on the store. In this case, multiple cooling units (18A) are connected in parallel to one condensing unit (18A).
B-1) to (18B-n) will be connected. Along with the parallel connection of each cooling unit (18B-1) to (18B-n), the pressure reducing valve (29
) and the fourth solenoid valve (37), branch pipes (45-1) to (45-n) of the pressure equalizing pipe (45) are connected correspondingly. (42) is a controller with a built-in timer, which controls the first to sixth solenoid valves (34) to (39) and the gear motor (39).
An open or close signal for operating the switch for a predetermined period of time is sent from each signal line (a) to (g).

During the defrosting operation of the first heat exchanger (11), the low temperature showcase (1) transfers the high pressure refrigerant and circulating air that has passed through the first heat exchanger to the second heat exchanger (5). ), air circulation is given priority over refrigerant circulation, and for this reason, the first heat exchanger (11) is placed at a lower position than the second heat exchanger (5). Also, the seventh
As shown in the figure, the upper inlet of the first heat exchanger (11) is connected to the outlet of the first low pressure liquid pipe (26) via a plurality of branched branch pipes (43), and the lower outlet is connected to the outlet of the first low pressure liquid pipe (26). The inlet of the low pressure gas pipe (27) is connected through a plurality of branched collecting pipes (44), and the refrigerant passing through the first heat exchanger (11) flows from the top to the bottom as shown by the arrow. , in the opposite direction to the flow of circulating air passing through the first heat exchanger (11). Further, the second heat exchanger (5) is also the same as the first heat exchanger (
Similar to 11), the refrigerant is introduced from the top and discharged from the bottom.

Next, the operation of each low temperature showcase (1) will be explained.

[0013] Now, the damper (4A) is closed and the second damper (4A) is closed.
As shown in the figure, the inner layer (13) and outer layer (7) are each independent. At this time, each of the first, second and sixth solenoid valves (34
) (35) and (39) are open, and the third, fourth, and fifth solenoid valves (36), (37, and 38) are closed, and in such a state, the refrigerant compressor (19) is When activated, the refrigeration system (
The refrigerant of 18) is transferred to the compressor (19)- as shown by the thick line in Figure 3.
Condenser (20) - Receiver (21) - Sixth solenoid valve (39)
- First solenoid valve (34) - Pressure reducing valve (22) - First heat exchanger (11) serving as an evaporator - Second solenoid valve (35) - Gas-liquid separator (23) - Compressor (19) During this period, the condensation is condensed and liquefied in the condenser (20) of the condensation unit (18A), and each cooling unit (18B-1)
The pressure is reduced by the pressure reducing valve (22) of ~(18B-n) and evaporated by the first heat exchanger (11). During this cooling operation (for example, 4 hours), the circulating air passing through the inner layer (13) with the inner layer blower (12) is transferred to the first heat exchanger (1
1), heat is exchanged with the low-pressure liquid refrigerant having an evaporation temperature of, for example, -15°C, and the cooling air becomes, for example, -6°C, and a cold air curtain (CA) is formed in the opening (3) as shown by the solid line arrow in Figure 2. The temperature of the storage chamber (17) is maintained at -4°C by forming a cooling system, and the stored items are maintained at an ice temperature (a temperature range of 0°C or lower and in which cells can be kept alive), for example, -2°C. During this time, in each cooling unit (18B-1) to (18B-n), both the first and second solenoid valves (34) and (35) are simultaneously opened and closed by a temperature sensor that detects the temperature of the storage room (17). Repeatedly set the temperature of the storage room (17) to the appropriate temperature (ice temperature)
to be maintained. On the other hand, the outer layer (
The circulating air passing through 7) flows along the outside of the cold air curtain (CA) at the opening (3) as shown by the solid line arrow in Figure 2, and is influenced by this cold air curtain into the low temperature showcase (1). The temperature becomes gradually lower than the outside air surrounding the air curtain, and acts as a protective air curtain (GA) that prevents the cold air curtain (CA) from contacting the outside air.

As the cooling operation progresses, the first heat exchanger (
11), the fourth solenoid valve (37) opens in response to a signal from the controller (42), and a portion of the liquid refrigerant from the first solenoid valve (34) flows into the high-pressure liquid branch pipe (28). ). This divided liquid refrigerant is depressurized by a pressure reducing valve (29),
It is evaporated in a second heat exchanger (5) serving as an evaporator, passes through a low pressure gas branch pipe (31), and flows into a low pressure gas pipe (27).
It joins with the low-pressure gas refrigerant that has passed through the first heat exchanger (11) and flows to the compressor (19), forming a second cycle shown by the thick line in FIG. 4. This second cycle is carried out for several tens of seconds to several minutes before the end of the cooling operation, that is, immediately before switching from cooling operation to defrosting operation, and this operation causes the first
Similarly to the heat exchanger (11), the second heat exchanger (5) also has a low temperature, and the circulating air passing through the outer layer (7) is lowered by the low pressure liquid passing through the second heat exchanger (5). Refrigerant (evaporation temperature is -20
C), and is maintained at approximately the same to slightly higher temperature (around -4 C) as the cooling air circulating through the inner layer (13). Note that during this cooling operation, the operation of the outer layer blower (6) may be stopped.

During this cooling operation, a defrosting start signal is output from the controller (42), and the first, second and sixth solenoid valves (34)
) (35) and (39) are closed, and both the third and fifth solenoid valves (
36) (38) opens and the damper (4A) opens as shown by the chain line in Figure 2, each cooling unit (18B-1) to (18
B-n) switches to defrosting operation, and the high-pressure refrigerant from the condenser (20), that is, the high-pressure gas-liquid mixed refrigerant, flows through the bypass circuit (32) - the first heat exchanger (11) - the connecting pipe ( 33)-
The third cycle shown in bold line in Figure 5, which flows from the fourth solenoid valve (37) - the pressure reducing valve (29) - the second heat exchanger (5) - the gas-liquid separator (23) - the compressor (19), is Form. This third
The first cycle is carried out for 10 to 20 minutes, for example.
This is the defrosting operation cycle of the first heat exchanger (11), and while the high pressure gas-liquid mixed refrigerant from the bypass circuit (32) flows from the top to the bottom of the first heat exchanger (11), the circulating air After being heat exchanged with the liquid and becoming a supercooled liquid of approximately 5°C, and gradually melting the frost in the first heat exchanger (11) with its sensible heat, the connecting pipe (33) and the fourth solenoid valve ( 37) to the second heat exchanger (5), and for example, other cooling units (18B-2) to (18B) than the first heat exchanger (11) of the cooling unit (18B-1). -n) first
When the refrigerant pressure in the heat exchanger (11) is low, it passes through the pressure equalization pipe (45) to the cooling units (18B-2) to (18).
A part of it flows to the second heat exchanger (5) of B-n). On the other hand, the circulation air that has passed through the first heat exchanger is interrupted from flowing in the inner layer (13) by the damper (4A), flows through the window (4C) to the outer layer (7), and is then transferred to the second heat exchanger (5).
) and is cooled to a temperature of around -4°C by exchanging heat with the low-pressure refrigerant passing through the refrigerant. This cooled circulating air is blown out from the outer layer air outlet (8) toward the opening (3), and is created as a medium-temperature air curtain (MA) around 0°C, which has a slightly higher temperature than the air curtain (CA) during cooling operation. is formed, and the cycle of return from the inner layer suction port (15) to the inner layer (13) as indicated by the chain line arrow in FIG. 2 is repeated.

As the defrosting operation progresses, the condensing unit (1
When the frost in the first heat exchanger (11) of the cooling unit (18B-n) closest to 8A) melts, the temperature switch (36A) provided in this cooling unit operates at a refrigerant temperature of, for example, 5°C. and the first, second and sixth solenoid valves (34) (
35) While the closed state of (39) continues, the third solenoid valve (36) first closes to stop the refrigerant supply to the first heat exchanger (11). Next, the cooling unit (18B-4), (
18B-3), (18B-2) to (18B-1) 3rd
The solenoid valve (36) operates in the same way in sequence, and finally the controller (4)
When the fifth solenoid valve (38) closes in response to the defrosting end signal from 2), the high-pressure gas-liquid mixed refrigerant serving as the defrosting heat source is no longer supplied to each cooling unit (18B-1) to (18B-n).
The first of each cooling unit (18B-1) to (18B-n)
This is a so-called pump-down operation in which the residual liquid refrigerant (including some saturated gas) in the first heat exchanger (11) is recovered to the liquid receiver (21), and the liquid refrigerant in each first heat exchanger (11) is recovered. As shown by the bold line in Figure 6, the connecting pipe (33), the fourth solenoid valve (37),
The liquid flows through the pressure reducing valve (29), the second heat exchanger (5), the gas-liquid separator (23), the compressor (19), the condenser (20), and the liquid receiver (21). The refrigerant is stored as a high-pressure liquid refrigerant in the container (21). This pump-down operation is performed for several minutes to more than ten minutes as the defrosting operation of the first heat exchanger (11) ends, and during this time, for example, the first heat exchanger (11) of the cooling unit (18B-n) ) Among the refrigerants, saturated gas and liquid refrigerant are sequentially drawn into the corresponding second heat exchanger (5) through the communication pipe (33), and are also drawn into the other cooling unit (18B-) through the pressure equalization pipe (45). By indirectly sucking the residual liquid refrigerant from 1) into the second heat exchanger (5), a part of it evaporates in the first heat exchanger (11) and uses this latent heat of vaporization to In addition to being able to provide a cooling effect to the heat exchanger (11) of the cooling unit (
18B-1) can be recovered quickly, and the refrigerant can be collected as a liquid from the pressure reducing valve (29) or from the pressure equalizing pipe (45) and the pressure reducing valve (
The refrigerant flowing from 29) to the second heat exchanger (5) becomes a low-pressure liquid refrigerant, evaporates while passing through this second heat exchanger, and uses this latent heat of evaporation to transfer to the second heat exchanger. (5) will have a cooling effect. Further, this pump-down operation is also a time for draining the dew adhering to the first heat exchanger (11).

[0017] With the end of the pump down operation, the third
The fourth and fifth solenoid valves (36), (37), and (38) close, and the first, second, and sixth solenoid valves (34, 35)
(39) is opened and the cooling operation shown in FIG. 3 is resumed.

Therefore, according to such an operation circuit, the first heat exchanger (11) of the cooling unit (18B-1), which is far from the condensing unit (18A) in terms of piping distance, is connected to the first heat exchanger (11) during the defrosting operation. The liquid refrigerant that accumulates inside the cooling unit (18
B-1), and a part of the liquid refrigerant is passed through the pressure equalization pipe (45) to the condensation unit (18).
The second heat exchanger (5) of the cooling unit (18B-n), which is closest to A) in terms of piping distance and where refrigerant shortage is likely to occur.
As a result, the amount of liquid refrigerant in the first heat exchanger (11) of the cooling unit (18B-1) decreases, and the temperature of this second heat exchanger tends to rise.
B-n) In addition to shortening the defrosting time of the first heat exchanger (11) of the cooling unit (18B-1), the second heat exchanger of the cooling unit (18B-n) vessel(
11) increases, the evaporation action of this second heat exchanger is promoted, and a predetermined cooling effect can be obtained. In addition, the pressure equalizing pipe (45) connects the cooling unit (18B-1) with a large storage amount of liquid refrigerant to each cooling unit (18B-3) to
Because part of the refrigerant is sent to the refrigerant compressor (18B-n), the circulating refrigerant does not stagnate or stagnate in one place.
It is possible to increase the low pressure and force of the defrosting heat source, and improve the flow of the high-pressure gas-liquid mixed refrigerant that serves as the defrosting heat source.

[0019]

According to the present invention described above, during the defrosting operation of the first heat exchanger, part of the liquid refrigerant accumulated in the first heat exchanger of one cooling unit is reduced by the pressure equalizing action of the pressure equalizing pipe. Since the refrigerant is distributed to the second heat exchanger of another cooling unit, it is possible to prevent the refrigerant from stagnation, increase the low pressure force of the compressor, and maintain good refrigerant circulation.

[Brief explanation of drawings]

FIG. 1 is a refrigerant circuit diagram of the entire refrigeration system.

FIG. 2 is a longitudinal cross-sectional view of a low-temperature showcase with a cooling unit.

FIG. 3 is a refrigerant circuit diagram showing a first cycle of the refrigeration system.

FIG. 4 is a refrigerant circuit diagram showing a second cycle of the refrigeration system.

FIG. 5 is a refrigerant circuit diagram showing the third cycle of the refrigeration system.

FIG. 6 is a refrigerant circuit diagram showing pump-down operation of the refrigeration system.

FIG. 7 is an overall perspective view in which both the first and second heat exchangers are connected.

FIG. 8 is a refrigerant circuit diagram of the entire conventional refrigeration system.

[Explanation of symbols]

5 Second heat exchanger 11 First heat exchanger 19 Refrigerant compressor 20 Condenser 23 Gas-liquid separator 29 Pressure reducing valve 32 Bypass circuit 33 Connecting pipe 45 Pressure equalization pipe

Claims (1)

[Claims] Claim 1: One condensation unit consisting of a refrigerant compressor and a condenser is composed of a first heat exchanger and a second heat exchanger connected in parallel to the first heat exchanger. When a plurality of cooling units are connected via piping and the first heat exchanger of each cooling unit is in defrosting operation, the refrigerant is transferred to the refrigerant compressor - condenser -
Bypass circuit - first heat exchanger - communication pipe - pressure reducing valve - second
A heat exchanger--piping is connected to return the refrigerant to the refrigerant compressor through a gas-liquid separator, and a second heat exchanger that is paired with this arbitrary first heat exchanger is connected via piping to return to the refrigerant compressor. A refrigeration system in which a part of the refrigerant reaching the exchanger is connected to a second heat exchanger of another cooling unit through a pressure equalizing pipe.