JP2846771B2 - Cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for vertically arranging a cooler in a duct to circulate circulating air from below to above and to defrost the cooler by a high-temperature refrigerant in a refrigerant circuit. It is.

[0002]

2. Description of the Related Art Conventionally, in a cooling apparatus of this type, for example, in a low-temperature showcase, as shown in Japanese Patent Application Laid-Open No. 2-101368 (F25D21 / 06), two layers of ducts are formed inside and outside the heat insulating wall in the vertical direction. The inner layer duct is provided with an inner layer cooler (inner layer evaporator) and the outer layer duct is provided with an outer layer cooler (outer layer evaporator). The inner layer blower and the outer layer blower circulate the circulating air upward from below to form a double air curtain at the opening. During the defrosting of the inner layer cooler that exerts a cooling action, the high-temperature and high-pressure refrigerant discharged from the compressor flows to the inner layer cooler and is heated, and the condensed refrigerant flows to the outer layer cooler. To exert a cooling effect.

Conventionally, the refrigerant flows down from the top to the bottom in the cooler for the inner layer. Therefore, at the time of defrosting, the heat from the hottest pipe at the top of the cooler, which is on the leeward side of the circulating air, is transferred to the cooler. Before the heat exchange, it is brought into the refrigerator by the circulating air, and there is a problem that the defrosting efficiency of the cooler decreases and the temperature inside the refrigerator increases. Therefore, in the above-mentioned publication, the air before the heat exchange with the cooler for the outer layer is caused to flow to the cooler for the inner layer by stopping the blower for the inner layer at the time of defrosting the cooler and opening the damper for dividing the duct to open the duct. . According to this configuration, since the inner-layer blower is stopped during the defrosting of the inner-layer cooler, the heat at the time of defrosting is not sent out to the inside of the refrigerator as described above, and the drainage of the drainage structure is performed. The occurrence of ice burn on the tray is also prevented.

[0004]

However, when the inner layer blower is stopped during the defrosting of the inner layer cooler, the air curtain at the opening is also weakened, and the adverse effect of the intrusion of the outside air becomes unfavorable. In addition, if a system is adopted in which the refrigerant flows upward from the lower part of the cooler which is the windward side of the circulating air in order to solve the above problem, the refrigerant is pushed up in a meandering manner against the gravity. Therefore, the circulation efficiency of the refrigerant is reduced. In particular, if a method is adopted in which the refrigerant is branched from a plurality of pipes and the refrigerant flows upward from the bottom in order to reduce the frictional resistance between the inner wall of the refrigerant pipe and the flowing refrigerant, the flow of the liquid refrigerant due to the inertia during the flow of the refrigerant may increase. The liquid refrigerant accumulates in the pipe and is sealed, and the flow of the refrigerant in the cooler is not uniform, which causes a partial defrosting problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and suppresses heat release to the outside of the cooler when the cooler is defrosted, and improves the defrosting efficiency of the cooler. It is an object to provide an improved cooling device.

[0006]

According to the first aspect of the present invention, there is provided a cooling device in which a cooler is vertically provided in a duct, and circulating air is circulated from bottom to top in the cooler. The cooler is defrosted by a high-temperature refrigerant, and the cooler is composed of a plurality of heat exchange fins provided in a vertical direction and refrigerant pipes inserted in these fins and arranged in a meandering manner. The refrigerant inlet of the refrigerant pipe is disposed at the lower part of the cooler, and the refrigerant pipe connected to the refrigerant inlet is drawn to the upper part of the cooler, and is disposed so as to descend in a meandering manner therefrom. It is characterized by.

According to a second aspect of the present invention, a cooling device is provided vertically in a duct, circulating air is circulated from bottom to top in the cooling device, and the cooling device is heated by a high-temperature refrigerant in a refrigerant circuit. The defroster, the cooler is composed of a plurality of heat exchange fins provided in the vertical direction, and a refrigerant pipe inserted through these fins and arranged in a meandering manner, the refrigerant of this refrigerant pipe The inlet portion is constituted by a single pipe, and is arranged at the lower part of the cooler, and the refrigerant pipe connected to the refrigerant inlet part is routed to the upper part of the cooler, and is branched into a plurality of pipes therefrom. It is arranged so as to descend in a meandering state in a state.

Further, in the cooling device according to the third aspect of the present invention, a cooler is vertically installed in a duct, and circulating air is circulated from bottom to top in the cooler, and the cooler is heated by a high-temperature refrigerant in a refrigerant circuit. Defrosting, the cooler is composed of a plurality of heat exchange fins provided in the vertical direction, refrigerant pipes inserted through these fins and arranged in a meandering manner, the fins of the cooler The density of the lower part is sparser than the upper part, and the refrigerant inlet part of the refrigerant pipe is arranged at the lower part of the cooler,
The refrigerant pipe connected to the refrigerant inlet is routed to the upper part of the cooler, and is disposed so as to descend in a meandering manner therefrom.

Further, the cooling device of the invention according to claim 4 is
A cooler is installed vertically in the duct, and circulating air is circulated from bottom to top in this cooler, and the cooler is defrosted by high-temperature refrigerant in the refrigerant circuit, and the cooler is provided in the vertical direction It consists of a plurality of heat exchange fins and a refrigerant pipe inserted through these fins and arranged in a meandering manner, and the fins have lower density compared to the upper part of the cooler,
The refrigerant inlet part of the refrigerant pipe is constituted by a single pipe and arranged at the lower part of the cooler, and the refrigerant pipe continuous with the refrigerant inlet part is routed to the upper part of the cooler and from there to a plurality of pipes It is characterized by being arranged so as to be branched and to meander downward in that state.

[0010]

According to the cooling device of the first aspect of the present invention, the refrigerant inlet of the refrigerant pipe of the cooler is provided in the lower part of the cooler which is on the windward side of the circulating air. Some of the latent and sensible heat of the high refrigerant is released into the circulating air, where the warmed air flows to the cooler above it. Therefore, when cooled by the cooler, the unsaturated wet circulating air becomes saturated wet air and the lower part and the center of the cooler where a lot of frost grows grows, and this warmed air heats from the outside, and the inside of the refrigerant pipes is heated. The defrosting ability near the center of the cooler can be improved in accordance with the internal heating from the flowing high-temperature refrigerant. In addition, since the defrost water dripped from the cooler is reheated at the refrigerant inlet, re-freezing in the drainage structure below the cooler can be prevented. Further, since the refrigerant pipe coming out of the refrigerant inlet is once routed to the upper part of the cooler and disposed so as to descend therefrom, there is no problem in the circulation efficiency of the refrigerant.

Further, according to the cooling device of the second aspect of the present invention, since the refrigerant inlet of the refrigerant pipe of the cooler is provided in the lower part of the cooler which is on the windward side of the circulating air, the temperature of the cooler is the highest when defrosting. Part of the latent heat and sensible heat of the high-refrigerant is released to the circulating air, where the warmed air flows to the cooler above it. It is possible to improve the defrosting ability near the center of the cooler by heating the vicinity of the center of the cooler where frost formation grows as air from the outside with this warmed air in accordance with the internal heating from the refrigerant pipe. it can. Also,
Similarly, since the defrost water dripped from the cooler is reheated at the refrigerant inlet, refreezing in the drainage structure below the cooler can be prevented. In particular, the refrigerant inlet is composed of a single pipe, and once routed to the top of the cooler, branches to multiple pipes and descends from there, reducing the frictional resistance between the refrigerant and the pipe. At the same time, after branching, the refrigerant only descends, so that the refrigerant flow path is not blocked by the liquid refrigerant.

Furthermore, according to the cooling device of the third aspect of the present invention, since the refrigerant inlet of the refrigerant pipe of the cooler is provided in the lower part of the cooler, which is on the windward side of the circulating air, the temperature of the cooler is highest when defrosting. Some of the latent heat and sensible heat of the high-refrigerant is released to the circulating air, where the warmed air flows to the cooler above it, so that the unsaturated wet circulating air is saturated when cooled by the cooler. Heating the lower part and the vicinity of the center of the cooler where frost formation grows as humid air from the outside with this warmed air according to the internal heating from the refrigerant pipe,
The defrosting ability near the center of the cooler can be improved. Similarly, since the defrost water dripping from the cooler is reheated at the refrigerant inlet, re-freezing in the drainage structure below the cooler can be prevented. Further, since the refrigerant pipe coming out of the refrigerant inlet is once routed to the upper part of the cooler and disposed so as to descend therefrom, there is no problem in the circulation efficiency of the refrigerant. In particular, since the fins of the cooler have a lower density compared to the upper part, the windward side where the refrigerant inlet where the temperature is lowest during cooling by the cooler is located is blocked by frost. You can extend the time.

According to the cooling device of the fourth aspect of the present invention, the refrigerant inlet of the refrigerant pipe of the cooler is provided in the lower part of the cooler, which is on the windward side of the circulating air. Part of the latent heat and sensible heat of the refrigerant is released to the circulating air,
Then, the warmed air flows to the cooler above it.Therefore, during cooling by the cooler, the unsaturated wet circulating air becomes saturated wet air and the lower part of the cooler and the vicinity of the center where a lot of frost grows. Heat can be externally heated by the warmed air in accordance with the internal heating from the refrigerant pipe, so that the defrosting ability near the center of the cooler can be improved. Similarly, since the defrost water dripping from the cooler is reheated at the refrigerant inlet, re-freezing in the drainage structure below the cooler can be prevented. Furthermore, the refrigerant inlet is composed of a single pipe, and once routed to the upper part of the cooler,
Since the refrigerant is branched into a plurality of pipes and descends therefrom, the frictional resistance between the refrigerant and the pipes is reduced, and the refrigerant only drops after branching, so that the refrigerant flow path is blocked by the liquid refrigerant. Does not occur. In particular, since the fins of the cooler have a lower density compared to the upper part, the windward side where the refrigerant inlet where the temperature is lowest during cooling by the cooler is located is blocked by frost. You can extend the time.

[0014]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a cooler 49 for an inner layer of a low-temperature showcase S as an embodiment of the cooling device of the present invention, FIG. 2 is a side view thereof, FIG. 3 is a vertical side view of the low-temperature showcase S, and FIG. The refrigerant circuit diagrams of the low-temperature showcase S are respectively shown. In FIG. 3, a low-temperature showcase S is an open showcase in which a main body is constituted by a heat insulating wall 42 having an opening 43 for storing and taking out products in front thereof, and a predetermined interval is provided inside the heat insulating wall 42. Then, the first partitioning plate 44 is provided, and the second partitioning plate 44 is provided inside the first partitioning plate 44 at a predetermined interval.
By disposing the partition plate 46, the inner and outer two-layer duct 4
7 and 48. Inside the inner layer duct 47, a plate fin type cooler 49 for the inner layer as described later is provided.
In addition, an axial-flow type inner-layer fan 51 constituted by a DC motor or an AC motor is disposed, and an outer-layer fan 53 similar to the plate-fin-type outer-layer cooler 52 is also disposed in the outer-layer duct 48.

The cooler 52 for the outer layer is disposed at a position higher than the cooler 49 for the inner layer, and both ducts 47 and 48 are provided at the upper edge of the opening 43 at the inner layer discharge ports arranged side by side. In addition to communicating with the outer layer discharge port 56, each of them communicates with a suction port 57 formed at the lower edge of the opening 43. Further, a plurality of shelves 59 are erected in a storage room 58 as a storage formed inside the second partition plate 46 in the heat insulating wall 42 and used for displaying food. Also, the first partition plate 4
4, a window hole 69 is formed between the two coolers 49 and 52. The window hole 69 is opened and closed by a damper 72 driven by a motor 71.

Next, in the refrigerant circuit of FIG. 4, a discharge pipe 2 is connected to a refrigerant discharge side 1D of a compressor 1 constituted by a scroll compressor or a semi-hermetic compressor. It is connected to the refrigerant inlet side 3A. An outlet pipe 4 is connected to the refrigerant outlet 3B of the condenser 3, and the outlet pipe 4 is connected to a refrigerant inlet 5A of the receiver tank 5. A dryer 7, a sight glass 8, a valve 9, solenoid valves 10 and 11 are connected in series to an outlet pipe 6 connected to a refrigerant outlet side 5B of the receiver tank 5, and this solenoid valve 11 is an expansion valve 12
Is connected to the inlet side 49A of the cooler 49 for the inner layer.

The outlet 49B of the cooler 49 for the inner layer is connected to the accumulator 16 via the auxiliary accumulator 40 from the low pressure side pipe 15 via the solenoid valve 14. An electromagnetic valve 18 is provided in a bypass pipe 17 that bypasses the electromagnetic valve 11 and the expansion valve 12, and a pipe 19 branched from between the electromagnetic valve 11 and the expansion valve 12 is connected to an outer layer through the electromagnetic valve 20 and the expansion valve 21. Is connected to the cooler 52. The outlet side of the outer layer cooler 52 is connected to the low-pressure side pipe 15, and
The pipe 24 branched from between the outlet side 49B of the inner layer cooler 49 and the solenoid valve 14 is connected to the inlet side of the solenoid valve 20 via a check valve 25. Further, the suction side pipe 26 connected to the outlet side of the accumulator 16 is connected to the suction side 1 of the compressor 1.
Connected to S.

A defrosting pipe 30 branched from the discharge pipe 2 of the compressor 1 is connected to the outlet side of the solenoid valve 10 via a solenoid valve 31 and similarly branched from the discharge pipe 2 of the compressor 1. The pipe 32 is connected to the low-pressure pipe 15 via a solenoid valve 33 and a low-pressure regulating valve 34.

Here, as shown in FIGS. 1 and 2, the inner layer coolers 49 are opposed to each other at a predetermined interval, and are provided between two tube sheets 61 and 62 disposed vertically. Aluminum heat exchange fins 63 are provided in parallel with each other.
A refrigerant pipe 64 is inserted in a meandering manner through the first and second fins 63. The refrigerant inlet portion 66 of the refrigerant pipe 64 that is continuous from the inlet side 49A of the cooler 49 is provided so as to reciprocate once from the lowermost end of the cooler 49 left and right. The cooler 49 is once routed to the top of the cooler 49. The refrigerant pipe 64 continuing from the pipe 67 is connected to the cooler 49.
It is arranged so as to descend in a meandering manner from the uppermost part.

Next, the operation of the low-temperature showcase S will be described. At the time of the cooling operation by the cooler 49 for the inner layer, the control device (not shown) controls the solenoid valves 10, 11 and 1.
4 is opened, the other solenoid valves are closed, and the compressor 1 is operated. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 radiates heat in the condenser 3 and condenses, and flows into the receiver tank 5 as a gas-liquid mixed refrigerant. In the receiver tank 5, the refrigerant is gas-liquid separated, and the liquid refrigerant accumulates downward and passes from the outlet side 5A through the outlet side pipe 6 as shown by the solid line arrow in FIG.
After passing through 0 and 11 and being throttled by the expansion valve 12, it flows into the refrigerant pipe 64 of the cooler 49 for the inner layer from the inlet side 49A.

The refrigerant flowing into the refrigerant pipe 64 first evaporates in the refrigerant inlet 66, and then is pushed up to the top of the cooler 49 through the pipe 67, and evaporates while flowing down there. Therefore, the temperature of the refrigerant inlet 66 below the cooler 49 becomes lowest. Thus, the refrigerant pipe 64
The refrigerant evaporated in the inner side is the outlet side 49B of the cooler 49 for the inner layer.
, Passes through the solenoid valve 14, passes through the low-pressure side pipe 15, and flows into the auxiliary accumulator 40 and then into the accumulator 16. Here, the unevaporated liquid refrigerant is separated, and only the gas refrigerant is sucked into the compressor 1 from the suction side pipe 26. A control device (not shown) controls the operation of the compressor 1 based on the temperature of the discharged cool air in the inner layer duct 47.

During the cooling operation, the control device closes the window hole 69 by the motor 71, and isolates the inner and outer layer ducts 47 and 48. The inner fan 51 and the outer fan 53
Are continuously operated, and the air sucked from the suction port 57 by the operation of the inner fan 51 is changed to the inner duct 47.
The inside is sent to the cooler 49 for the inner layer, and the inside of the cooler 49 is circulated from the bottom to the top and cooled by heat exchange.
Discharged from the inner layer discharge port 54. Thereby, the opening 43
Has a cold air curtain C as shown by the solid arrow in FIG.
While A is formed, a part circulates in the storage room 58 by the Cander effect, thereby cooling the inside of the storage room 58 to a predetermined refrigeration temperature.

On the other hand, by the operation of the outer layer fan 53, the air sucked in from the suction port 57 is sent to the outer layer cooler 52 through the outer layer duct 48. It rises in the outer layer duct 48 and is discharged from the outer layer discharge port 56. As a result, the air curtain C is provided in the opening 43 as shown by the broken arrow in FIG.
A protective air curtain GA is formed on the outside of A, and the effect of preventing outside air from entering through the opening 43 is obtained by reinforcing the air curtain CA.

The cooling operation for the inner layer 49 is performed by the cooling operation.
The frost grows on the inner layer, and after a predetermined period of time (for example, 3 hours) elapses, the control device controls the inner layer cooler 4.
9 is performed. In this defrosting operation, the control device opens the solenoid valves 31, 18, 20, and 33, and closes the other solenoid valves. Thereby, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 passes through the defrosting pipe 30 as shown by the dashed arrow in FIG.
2 to cooler 49 for inner layer from inlet side 49A
Flows into the refrigerant pipe 64.

The refrigerant that has flowed into the refrigerant pipe 64 first passes through the refrigerant inlet 66, is then pushed up to the top of the cooler 49 through the pipe 67, and flows down in a meandering manner therefrom. The high-temperature and high-pressure gas refrigerant flowing through the refrigerant pipe 64 radiates part of the latent heat or sensible heat there and is condensed,
The inner layer cooler 49 is heated by the heat radiation at this time, and the frost formed on the cooler 49 is melted. In particular,
Since the high-temperature and high-pressure gas refrigerant flows into the refrigerant inlet 66 below the cooler 49 first, the refrigerant inlet 66 is strongly heated and has the highest temperature. On the other hand, since the air is circulated from the bottom to the top in the cooler 49 for the inner layer by the inner layer fan 51, the air warmed at the refrigerant inlet 66, which is at a high temperature, rises therefrom and is cooled. 49 will flow upward from the center.

Here, during the cooling operation by the cooler 49 for the inner layer, the unsaturated wet circulating air flowing into the cooler 49 is cooled by the refrigerant pipe 64 and the fins 63 and is cooled.
Around the center of No. 9, saturated moist air is formed. Therefore, the cooler 4
9, the amount of frost increases rapidly in the vicinity of the center, but in the present invention, as described above, the air warmed at the refrigerant inlet 66 below the cooler 49 flows to the central part of the cooler 49 above it. In accordance with the direct heating from the refrigerant pipe 64, the warm air heats the central portion of the cooler 49, so that a large amount of frost near the central portion of the cooler 49 as described above is smoothly melted.

Further, since the heat from the refrigerant pipe 64 is efficiently used for defrosting the cooler 49, the amount of heat released from the cooler 49 into the storage chamber 58 by the circulating air is reduced. Therefore, the adverse effect on the temperature of the storage room 58 can be reduced. Furthermore,
During the defrosting of the cooler 49, defrost water or ice blocks at around 0 ° C., which is dripped from above the refrigerant inlet 66, is reheated at the refrigerant inlet 66, so that Re-freezing in the provided drainage structure (not shown) is prevented,
Thereby, the problem of poor drainage of the defrost water can be solved. Furthermore, since the refrigerant is not pushed upward from the lower part of the cooler 49 in a meandering manner,
Refrigerant can also flow without delay.

The refrigerant condensed inside the inner layer cooler 49 in this manner is supplied from the pipe 24 to the check valve 25 and the solenoid valve 2.
After passing through 0 and being throttled by the expansion valve 21, it flows into the cooler 52 for the outer layer and evaporates. Further, during the defrosting operation, the control device opens the window hole 69 by the motor 71, and connects the inner layer duct 47 below the outer layer cooler 52 to the outer layer duct 4.
8 and the inner layer duct 4 above the cooler 49 for the inner layer.
8 closes. Thus, the air in the inner layer duct 47 whose temperature has increased due to the heat generated from the cooler 49 for the inner layer is
It flows into the outer layer duct 48 and joins the air flowing there,
After being cooled by the outer layer cooler 52, the air is discharged from the outer layer discharge port 56, so that the flow of heat from the inner layer cooler 49 into the storage chamber 58 can be further reduced.

The refrigerant evaporated in the outer layer cooler 52 is similarly supplied from the auxiliary accumulator 40 to the accumulator 1.
6 and return to the compressor 1. Further, during this defrosting, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the suction-side pipe 15 through the solenoid valve 33 and the low-pressure pressure regulating valve 34, whereby the low-pressure side pressure of the compressor 1 is reduced. Is prevented from falling too much. Then, when the temperature of the cooler 49 for the inner layer increases to, for example, + 8 ° C. by the defrosting operation, the control device ends the defrosting operation and returns to the cooling operation.

Next, FIG. 5 shows another cooler 4 for the inner layer.
9 is a front view, FIG. 6 is a side view thereof, and FIG. 7 is a perspective view of a cooler 49 for the inner layer and a cooler 52 for the outer layer in that case. In each drawing, the same reference numerals as those in FIGS. 1 to 4 are the same. In this case, the refrigerant inlet portion 6 of the refrigerant pipe 64 continuous from the inlet side 49A of the cooler 49.
Reference numeral 6 denotes a pipe provided with a single pipe which reciprocates the lowermost end of the cooler 49 left and right two times, and a pipe extending continuously from the outlet of the refrigerant inlet 66 to the uppermost side of the cooler 49. 67
A branch pipe 65 is attached to an upper end of the refrigerant pipe, from which the refrigerant pipe 64 is branched into two pipes 64A and 64B.
The two refrigerant pipes 64A and 64B are arranged so as to descend in a meandering manner in a line in front and rear from the top of the cooler 49,
After passing just above the refrigerant inlet 66, the refrigerant is merged again by the merge pipe 68 to form a single pipe, which is connected to the outlet 49B.

According to this structure, the same defrosting effect as described above can be achieved, and at the same time, the inner diameter of the refrigerant pipe 64 is doubled (refrigerant pipe 64A + 64B), so that the frictional resistance between the pipe inner surface and the flowing refrigerant is reduced. Is done. Also, the refrigerant pipes 64A and 6A
The branch to 4B is not performed in the refrigerant inlet 66 or in the middle of the pipe 67, but is performed at the upper end of the pipe 67 routed to the top of the cooler 49. The bias is eliminated, and the refrigerant that has flowed out of the branch pipe 65 flows down with little rise thereafter.
Therefore, as described above, there is no inconvenience such as the liquid refrigerant accumulating in the pipe in which the liquid refrigerant increases and being liquid-sealed,
Thereby, the flow of the refrigerant in the cooler 49 is made uniform,
The entire cooler 49 can be defrosted uniformly.

Next, FIG. 8 shows a front view of still another cooler 49 for the inner layer, and FIG. 9 shows a front view of still another cooler 49 for the inner layer. 1 and 5 in FIG.
8, the structure of the refrigerant pipe 64 in FIG. 8 is the same as that in FIG. 1, and the structure of the refrigerant pipe 64 in FIG. 9 is the same as that in FIG. Also, the heat exchange fins 63 are vertically separated from the center of the cooler 49, and the upper fins 63A are arranged so that the density thereof is high and the lower fins 63B are less dense than the upper ones. Have been. As a result, the density of the fins 63B on the inlet side of the circulating air flowing through the cooler 49 becomes low, and the refrigerant inlet 66 of the refrigerant pipe 64 is located in the low-fin portions 63B. .

Here, since the refrigerant inlet 66 of the refrigerant pipe 64 is located on the windward side below the cooler 49, the temperature of the refrigerant inlet 66 becomes lowest during the cooling operation by the cooler 49. The amount of frost on the inlet side of the circulating air of the cooler 49 increases. However, according to the cooler 49 of FIGS. 8 and 9, the fin 63
Since the density of B is lower than that of the upper part, in addition to the effect at the time of defrosting, the time until the windward side of the cooler 49 is closed by frost formation can be extended, Vessel 4
9 can be maintained for a long time.

In each of the above embodiments, a low-temperature showcase in which a cooler is provided in each of the inner and outer ducts 47 and 48 has been described. However, the present invention is not limited thereto, and only the cooler 49 for the inner layer and the inner fan 51 are provided. A low-temperature showcase may be used. Further, the present invention is not limited to the low-temperature showcase, but is effective for various cooling devices such as other prefabricated refrigerators.

[0035]

As described above in detail, according to the first aspect of the present invention, the refrigerant inlet of the refrigerant pipe of the cooler is provided at the lower part of the cooler which is on the windward side of the circulating air. Part of the latent heat and sensible heat of the refrigerant with the highest temperature is released to the circulating air, where the warmed air can heat the lower part of the cooler and the vicinity of the center where a lot of frost grows. The defrosting ability in the lower part and near the center of the cooler can be improved in accordance with the heating. In addition, the amount of heat released to the outside of the cooler can be reduced, and the adverse effect on the cooling efficiency of the cooling device can be suppressed. Furthermore, since the defrost water dripping from the cooler is reheated at the refrigerant inlet, re-freezing in the drainage structure below the cooler can be prevented, and the drainage failure can be eliminated, and the refrigerant inlet can be eliminated. The refrigerant pipe exiting from the cooler is routed to the upper part of the cooler and disposed so as to descend therefrom, so that there is no problem in the circulation efficiency of the refrigerant.

Also, according to the second aspect of the present invention, the refrigerant inlet portion of the refrigerant pipe of the cooler is provided in the lower part of the cooler which is on the windward side of the circulating air. Part of the latent heat and sensible heat is released to the circulating air, where the warmed air can heat the lower part and near the center of the cooler where frost formation grows a lot. It is possible to improve the defrosting ability near the lower part and the center. Similarly, the amount of heat released to the outside of the cooler can be reduced, and adverse effects on the cooling efficiency of the cooling device can be suppressed. Furthermore, since the defrosted water dripping from the cooler is similarly reheated at the refrigerant inlet, refreezing in the drainage structure below the cooler can be prevented, and defective drainage can be eliminated. In particular, the refrigerant inlet portion is configured with a single pipe, and once routed to the upper part of the cooler, is branched from there to a plurality of pipes and descends, so that the flow resistance of the refrigerant is reduced, The refrigerant flow path is not blocked by the liquid refrigerant, and the entire cooler can be defrosted uniformly.

Further, according to the third aspect of the present invention, since the refrigerant inlet of the refrigerant pipe of the cooler is provided in the lower part of the cooler, which is on the windward side of the circulating air, the refrigerant having the highest temperature when the cooler is defrosted. Part of the latent heat and sensible heat is released to the circulating air, where the warmed air can heat the lower part and near the center of the cooler, where frost formation grows a lot. It is possible to improve the defrosting ability near the lower part and the center. Similarly, the amount of heat released to the outside of the cooler can be reduced, and adverse effects on the cooling efficiency of the cooling device can be suppressed. Furthermore, since the defrosted water dripping from the cooler is similarly reheated at the refrigerant inlet, refreezing in the drainage structure below the cooler can be prevented, and defective drainage can be eliminated. Furthermore, since the refrigerant pipe coming out of the refrigerant inlet is once routed to the upper part of the cooler and disposed so as to descend therefrom, there is no problem in the refrigerant circulation efficiency. In particular, since the fins of the cooler have a lower density compared to the upper part, the windward side where the refrigerant inlet where the temperature is lowest during cooling by the cooler is located is blocked by frost. The time can be extended, and the cooling effect of the cooler can be maintained for a long time.

According to the fourth aspect of the present invention, since the refrigerant inlet of the refrigerant pipe of the cooler is provided in the lower part of the cooler on the windward side of the circulating air, the latent heat of the refrigerant having the highest temperature during the defrosting of the cooler. And part of the sensible heat is released to the circulating air, where the warmed air can heat the lower part of the cooler and the vicinity of the center where a lot of frost grows. The defrosting ability near the center can be improved. Similarly, the amount of heat released to the outside of the cooler can be reduced, and adverse effects on the cooling efficiency of the cooling device can be suppressed. Furthermore, similarly, since the defrost water dripping from the cooler is reheated at the refrigerant inlet portion, it prevents re-freezing in the drainage structure below the cooler,
Drainage failure can be eliminated. Furthermore, the refrigerant inlet portion is configured with a single pipe, and once routed to the upper part of the cooler, is branched from there to a plurality of pipes so as to descend, so that the flow resistance of the refrigerant is reduced. Also, the refrigerant flow path is not blocked by the liquid refrigerant. In particular, the fins of the cooler have a lower density compared to the upper part,
It is possible to extend the time until the windward side where the refrigerant inlet where the temperature is lowest when cooling by the cooler is located is blocked by frost, and the cooling effect of the cooler can be maintained for a long time. .

[Brief description of the drawings]

FIG. 1 is a front view of a cooler for an inner layer of a low-temperature showcase as an embodiment of a cooling device of the present invention.

FIG. 2 is a side view of a cooler for an inner layer.

FIG. 3 is a vertical sectional side view of a low-temperature showcase.

FIG. 4 is a refrigerant circuit diagram of a low-temperature showcase.

FIG. 5 is a front view of another cooler for an inner layer.

FIG. 6 is a side view of another inner layer cooler.

FIG. 7 is a perspective view of another cooler for the inner layer and a cooler for the outer layer.

FIG. 8 is a front view of still another inner layer cooler.

FIG. 9 is a front view of still another inner layer cooler.

[Explanation of symbols]

 S Low-temperature showcase 47 Inner layer duct 49 Inner layer cooler 51 Inner layer fan 63 Fin 64 Refrigerant pipe 65 Branch pipe 66 Refrigerant inlet 67 Pipe

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F25B 39/00-41/06

Claims (4)

(57) [Claims] 1. A cooling device in which a cooler is installed vertically in a duct, circulating air is passed through the cooler from bottom to top, and the cooler is defrosted by high-temperature refrigerant in a refrigerant circuit. The vessel is composed of a plurality of fins for heat exchange provided in the vertical direction, and a refrigerant pipe inserted in the fin and arranged in a meandering shape, and a refrigerant inlet portion of the refrigerant pipe is provided at a lower part of the cooler. A cooling device, wherein the cooling device is disposed, and a refrigerant pipe connected to the refrigerant inlet portion is routed to an upper portion of the cooler, and is disposed so as to descend in a meandering shape therefrom. 2. A cooling device in which a cooler is installed vertically in a duct, circulating air is passed through the cooler from bottom to top, and the cooler is defrosted by high-temperature refrigerant in a refrigerant circuit. The vessel comprises a plurality of fins for heat exchange provided in the vertical direction, and refrigerant pipes inserted through the fins and arranged in a meandering shape, and the refrigerant inlet portion of the refrigerant pipe is a single pipe. The refrigerant pipe which is configured and arranged at the lower part of the cooler and connected to the refrigerant inlet is routed to the upper part of the cooler and branched therefrom into a plurality of pipes, and descends in a meandering state in that state. A cooling device, wherein the cooling device is arranged to perform cooling. 3. A cooling device in which a cooler is vertically installed in a duct, circulating air is circulated through the cooler from bottom to top, and the cooler is defrosted by high-temperature refrigerant in a refrigerant circuit. The heat exchanger comprises a plurality of heat exchange fins provided in the vertical direction, and a refrigerant pipe inserted in the fins and arranged in a meandering shape, wherein the fins are located at a lower portion as compared to an upper portion of the cooler. Density is reduced, the refrigerant inlet portion of the refrigerant pipe is arranged at the lower part of the cooler, and the refrigerant pipe connected to the refrigerant inlet part is routed to the upper part of the cooler, from which it descends in a meandering manner. A cooling device, wherein the cooling device is arranged to perform cooling. 4. A cooling device in which a cooler is vertically installed in a duct, circulating air is circulated through the cooler from bottom to top, and the cooler is defrosted by high-temperature refrigerant in a refrigerant circuit. The heat exchanger comprises a plurality of heat exchange fins provided in the vertical direction, and a refrigerant pipe inserted in the fins and arranged in a meandering shape, wherein the fins are located at a lower portion as compared to an upper portion of the cooler. Density is reduced, the refrigerant inlet portion of the refrigerant pipe is formed of a single pipe and is arranged at the lower part of the cooler, and the refrigerant pipe connected to the refrigerant inlet part is drawn to the upper part of the cooler. A cooling device characterized in that the cooling device is arranged so as to be turned and branched therefrom into a plurality of pipes, and to descend in a meandering state in that state.