KR100276513B1 - Low-temperature show-case - Google Patents

Abstract

The present invention relates to a low temperature showcase, and more particularly, to a low temperature showcase for achieving uniform cooling of a cooler and lengthening a defrost interval.

The present invention is a low-temperature showcase having defrosting means (71, 73) for arranging a plurality of coolers (11, 13) in series in the cooling duct (7) of the showcase body (3) and defrosting the coolers (11, 13). to be. The plurality of coolers 11 and 13 arranged in series are provided with return temperature detection sensors 31 and 33 which detect return temperatures for returning from the defrosting operation to the cooling operation by the defrosting means 71 and 73, respectively, and are downstream. The set temperature of the return temperature detection sensor 33 of the side cooler 13 is set lower than the set temperature of the return temperature detection sensor 31 of the downstream cooler 11, thereby completing the defrosting operation of the downstream cooler 13 quickly. It can be returned to the cooling operation.

Description

Low temperature showcase

The present invention relates to a low temperature showcase, and more particularly, to a low temperature showcase for controlling frost on a cooler.

Recently, various types of foods such as meat and fish, frozen foods and ice cream are sold in large retail stores such as supermarkets. These foods are stored and displayed in refrigerated or frozen showcases (hereinafter referred to as cryo showcases) to ensure that consumers can purchase fresh foods with proper temperature control.

The low temperature showcase includes a showcase body in which food is stored, a compressor comprising a compressor, a pressure reducing device, a condenser, and a cooler, and supplies cold air to the food in the showcase body using a cooler blower.

In this low temperature showcase, defrosting is performed by using a warmer or defrosting heater because frost may form on the cooler of the freezer during operation.However, a user who wishes that defrosting is not performed to the maximum extent possible when the super light is opened. In order to meet this desire, the cooler was enlarged and the defrost time interval was made as long as possible.

However, in the conventional configuration, it is possible to lengthen the defrost interval, but if the cooler is enlarged, there is a problem in that the operation time required for the defrosting operation becomes longer. For example, it has been proposed to reduce the defrosting operation time by dividing a large-sized cooler into two and attaching defrosting means such as a defrost heater to each of the divided coolers.

However, when the two coolers are arranged in the vertical direction in the cooling duct extending in the vertical direction, for example, frost or ice of the downstream cooler falls on the upstream cooler, resulting in a long defrost time of the upstream cooler.

Moreover, in order to lengthen the defrost interval, the upstream fin pitch of the cooler was roughened. However, since the conventional technology is configured to introduce the liquid refrigerant to the cold air downstream side of the cooler and to flow upstream in turn, it is derived from the upstream of the cold air of the cooler. There was a problem that degraded the ability.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a low temperature showcase that enables uniformization of idea in a plurality of coolers and at the same time lengthens the interval of defrosting operation.

1 is a longitudinal sectional view of a refrigerating showcase according to the first embodiment of the present invention.

2 is a schematic configuration diagram showing a refrigeration cycle and a control system in a first embodiment of the present invention.

3 is a longitudinal sectional view of the refrigerating showcase according to the second embodiment of the present invention.

4 is a schematic diagram illustrating a refrigeration cycle and a control system in a second embodiment of the present invention.

5 is a longitudinal sectional view of the refrigerating showcase according to the third and fourth embodiments of the present invention.

6 is a longitudinal sectional view of the refrigerating showcase according to the fifth embodiment of the present invention.

7 is a front view of the cooler in the fifth embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

1: refrigerated showcase 3: showcase body

7: Cooling duct 9: Cooler blower

11 upstream cooler 13 downstream cooler

31, 33: return temperature detection sensor 61: showcase side ECU

71, 73: defrost heater 81: main return temperature detection sensor

83: auxiliary return temperature detection sensor

In order to achieve the above object, the present invention is a low-temperature showcase having a defrost means for arranging a plurality of coolers in series in a cooling duct of a showcase body and defrosting each cooler, wherein the plurality of coolers arranged in series are the defrost means. And a return temperature detection sensor for detecting the return temperature for returning from the defrosting operation to the cooling operation by each of them.The set temperature of the return temperature detection sensor of the downstream cooler is set lower than the set temperature of the return temperature detection sensor of the upstream cooler. It is characterized by one.

In addition, the present invention is a low-temperature showcase having a defrost means for arranging a plurality of coolers in series in the cooling duct of the showcase body and defrosting each cooler, the defrost of the upstream cooler by the defrost means in the vicinity of the discharge port in the cooling duct A secondary return temperature detection sensor is installed which detects the return temperature for returning from the operation to the cooling operation and detects the return temperature from the defrost operation of the downstream cooler by the defrosting means near the outlet of the downstream cooler. It is characterized by installing a sensor.

In addition, the present invention is a low temperature showcase having a defrost means for arranging a plurality of coolers in series in the cooling duct of the showcase body and defrosting each cooler, the cooling in the defrost operation of the downstream cooler by the defrost means in the cooling duct. A defrost temperature detection sensor is installed to detect the return temperature for returning to operation, and a delay timer that measures a predetermined time from the return of the downstream cooler is installed. At this point, the upstream cooler is defrosted. It is characterized by returning.

In addition, the present invention is characterized in that the defrost means is a defrost heater.

In this invention, since the defrosting operation of the downstream side cooler is completed earlier than the defrosting operation of the upstream side cooler, the cooling operation can be performed by using the downstream side cooler after the defrosting operation is completed, and the defrosting operation time can be shortened.

As a result, since the defrosting operation time of the upstream side cooler becomes long, the upstream side cooler can be almost certainly defrosted even if a relatively large amount of frost and ice melts and falls to the downstream side side cooler.

In addition, in the low temperature showcase in which a plurality of coolers are arranged in series in the cooling duct of the showcase body, the pin pitch of the upstream side cooler is formed to be rougher than the pin pitch of the downstream side cooler so that the liquid refrigerant is located upstream of the upstream side cooler. It is configured to be introduced on the downstream side of the downstream side cooler from the downstream side and introduced so that it can be derived from the upstream side.

In the present invention, since the warmed refrigerant is passed upstream of the downstream cooler after passing through the upstream cooler and the downstream cooler, the fin surface temperature at the most upstream side of the narrow fin pitch of the cooler is increased to suppress the conception of this part. And defrost interval is long.

Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a longitudinal sectional view of a refrigerating showcase according to the first embodiment of the present invention. The refrigerating showcase of the present embodiment is a multi-stage open type with an open front surface and a separate installation type in which liquid refrigerant is supplied from a cooling unit arranged outdoors. The showcase main body 3 has a four-stage display stand 5 installed in its opening, and at the front of the display stand 5, an inner layer air curtain (indicated by the arrow in the A direction) and an outer layer air curtain (the flow is B). In the direction indicated by arrows).

The showcase body 3 is provided with a cooling duct 7 having a shape surrounding the display stand 5, a cooler blower 9 at the lower portion of the cooling duct 7, and an upstream cooler in the vertical portion from below. 11) and the downstream side cooler 13 are arranged, and the cooling air circulation supply means is constituted by these and the cold air suction opening 15 and the cold air discharge opening 17.

In addition, an air curtain blower (not shown) is disposed in the showcase body 3, and a blower tank 21 having a shape surrounding the cooling duct 7 is provided therein, and an air suction port 23 and an air discharge port. An air curtain generating means is constituted by (25).

31 is a 1st discharge side temperature sensor (return temperature detection sensor) which detects the exit temperature of the upstream cooler 11, and 33 is the 2nd exit temperature which detects the exit temperature of the downstream cooler 13; Sensor (return temperature detection sensor). The upstream side cooler 11 has a cooling fin pitch that is rougher than that of the downstream side cooler 13.

In the present embodiment, the cold air around the display stand 5 is sucked into the cooling duct 7 at the cold air inlet 15 by the cooler blower 9, and then cooled through the coolers 11 and 13 to a predetermined temperature. And is discharged toward the display rack 5 from the cold air discharge port 17. In addition, the air that generates the air curtain is sucked into the blower tank 21 at the air inlet 23 by the air curtain blower, and then discharged from the air outlet 25 toward the air inlet 23.

2 is a schematic diagram illustrating a refrigeration cycle and a control system thereof according to a first embodiment. As shown in the figure, the refrigerating cycle includes the compressors on both sides of the refrigerating showcase 1 and the compressors on the side of the first and second motor-expansion valves 37 and 39 and other cooling units 41 corresponding thereto. 43, the condenser 45, the receiver 47, and the like. In the figure, 49 is a condenser blower installed in the cooling unit 41, and 51 to 58 are refrigerant pipes which help to distribute the liquid refrigerant or gas refrigerant. Reference numeral 100 designates a defrosting means. The hot gas generated in the compressor 43 is bypassed to the condenser and transferred directly to both coolers 11 and 13 to remove frost attached to the coolers 11 and 13 by the hot gas. 81 and 83 are motor-expanded sides for defrosting.

The refrigeration showcase 1 has a showcase side control unit (hereinafter referred to as ECU) for controlling the driving of the cooler blower 9 and the first and second electric expansion sides 37 and 39 and the electric motor expansion sides 81 and 83 for defrosting. 61) is provided. The showcase side ECU 61 is composed of a CPU, an input / output interface, a ROM, a RAM, a timer counter, and the like. The input interface is connected to various sensors including the first and second exit temperature sensors 31 and 33. .

On the other hand, the cooling unit 41 is provided with the cooling unit side ECU 63 which drives and controls the compressor 43, the condenser blower 49, and the like. The cooling unit side ECU 63 is composed of an input / output interface, a ROM, a RAM, a timer counter, and the like starting with the CPU. In addition, the showcase side ECU 61 and the cooling unit side ECU 63 are connected by a communication line 65 and communicate with each other.

The operation of the first embodiment is described below.

When the refrigeration showcase 1 is connected to the cooling unit 41 and the operation of the refrigeration cycle is started, as shown in FIG. 2, the gas refrigerant in the receiver 47 has the refrigerant pipe 58 as indicated by the solid arrows. Aspirated by the compressor 43. The gas refrigerant is compressed to high temperature and high pressure in the compressor 43, and then introduced into the condenser 45 having the refrigerant pipe 51, and condensed and liquefied between the condensers 45.

Then, a part of the liquid refrigerant flows in the refrigerant pipe 52 divided into the refrigerant pipe 53 and is decompressed by the first electric expansion valve 37 formed in the refrigerant pipe 53 and flows into the upstream cooler 11. In addition, the remainder of the liquid refrigerant flows into the refrigerant pipe 52 from the refrigerant pipe 52 and is decompressed by the second electric expansion valve 39 formed in the refrigerant pipe 55 to flow into the downstream cooler 13. The liquid refrigerant evaporates and vaporizes in both coolers 11 and 13, and then circulates to the receiver 47 having the refrigerant pipes 54, 56 and 57, and is stored in the receiver 47, and then the refrigerant pipe 58 again. Is sucked into a compressor (43).

Both coolers 11 and 13 cool the air whose surface temperature falls below the freezing point by the latent heat of vaporization accompanying the vaporization of the liquid refrigerant. The cooled air is circulated by the cooler blower 9 as indicated by the arrow A (Fig. 1) in the showcase body 3, and the goods displayed on the display stand 5 are cooled to a predetermined temperature.

However, since the frost is attached to both coolers 11 and 13 when the cooling operation continues, the defrosting operation is performed at an appropriate interval. This defrosting operation flows hot gas as indicated by the dotted arrow by closing the first and second electric expansion sides 37 and 39 and opening the defrosting electric expansion sides 81 and 83 as shown in FIG.

In this embodiment, the defrosting operation is stopped by the defrosting means 100 in accordance with the outputs from the return temperature detection sensors 31 and 33. The set temperature of the return temperature detection sensor 33 of the downstream side cooler 13 is set lower than the set temperature of the return temperature detection sensor 31 of the upstream side cooler 11 and accordingly, the defrost of the downstream side cooler 13 is removed. The operation is returned earlier than the defrosting operation of the upstream side cooler 11.

That is, since the set temperature TS2 of the downstream cooler 13 is set lower than the set temperature TS1 of the upstream cooler 11 by a predetermined value (for example, 3 ° C), hot gas is introduced by the defrosting means 100. By this, the temperature of the downstream cooler 13 reaches the set temperature TS2 early. Then, the showcase side ECU 61 receives the signal from the return temperature detection sensor 33 and closes the defrosting motor expansion valve 83 and simultaneously opens the second motor expansion valve 39. According to this, the defrosting operation of the downstream cooler 13 is finished quickly, and at the same time, the downstream cooler 13 returns to the cooling operation.

Since the set temperature TS1 of the upstream side cooler 11 is as high as a predetermined value (for example, 3 ° C.), hot gas is introduced by the defrosting means 100 until the set temperature is reached. When the set temperature is reached, the defrosting operation is terminated later than the downstream cooler 13. In this case, the showcase-side ECU 61 receives the signal from the return temperature detection sensor 31 to close the defrosting motor expansion valve 81 and simultaneously opens the first motor expansion valve 37. According to this, all defrosting operation | movement is complete | finished and it returns to cooling operation.

And since the defrosting operation time of the upstream cooler 11 becomes long, even if a comparatively large amount of frost and ice melts and falls in the upstream cooler 11 in the downstream cooler 13, the upstream cooler 11 is almost reliably. Can be defrosted.

3 is a longitudinal sectional view of a refrigerating showcase according to a second embodiment of the present invention, and FIG. 4 is a schematic configuration diagram showing a refrigeration cycle and a control system thereof. As shown in these figures, the refrigerating showcase of the second embodiment is almost the same in its overall configuration as that of the first embodiment, but the showcases are shown in the lower portion (upstream side) of both coolers 11 and 13, except for the defrost means by hot gas. Defrost heaters 71 and 73 which are energized and controlled by the side ECU 61 are provided.

The operation of the second embodiment is described below.

In the present embodiment, the first and second outlet side temperature sensors 31 and 33 assist the temperature control of the two coolers 11 and 13 in the normal operation as in the first embodiment, but at the time of defrosting, as the return temperature detection sensor. Works. When the refrigerated showcase 1 is operated for a predetermined time, the showcase side ECU 61 starts defrosting of both coolers 11 and 13 based on the value of the built-in timer. During this defrost operation, the operation of the compressor 43 is stopped and the defrost heaters 71 and 73 are energized.

In the present embodiment, the return temperatures between the two coolers 11 and 13 are different. In other words, the return temperature TR2 of the downstream cooler 13 is set to be lower than the return temperature TR1 of the upstream cooler 11 by a predetermined value (for example, 3 ° C). Accordingly, the energization of the defrost heaters 71, 73 quickly reaches the return temperature TR2. Then, the showcase side ECU 61 receives the signal from the return temperature detection sensor 33 and disconnects the defrost heater 73, and simultaneously drives the compressor 43 to close the first electric expansion valve 37 and the second electric expansion valve 39. ). In this case, the defrosting operation of the downstream cooler 13 is ended quickly, and at the same time as the end, the downstream cooler 13 is returned to the cooling operation.

Since the return temperature TR1 of the upstream cooler 11 is as high as a predetermined value (for example, 3 ° C), energization of the defrost heater 71 is continued until the return temperature is reached. When the return temperature is reached, the defrosting operation is terminated later than the downstream cooler 13. In this case, the showcase side ECU 61 receives the signal from the return temperature detection sensor 31 and disconnects the defrost heater 71 and simultaneously opens the first electric expansion valve 37. This ends all defrosting operations and returns to the cooling operation.

According to this, since the defrosting operation time of the upstream cooler 11 is long, even if a comparatively large amount of frost and ice melts and falls to the downstream cooler 11 than the downstream cooler 13, the upstream cooler 11 is almost certain. I can defrost it.

5 is a longitudinal sectional view of the refrigerating showcase according to the third embodiment of the present invention. According to this figure, the refrigerating showcase of the third embodiment is almost the same as the second embodiment, but the cooler outlets 17 in the cooling ducts 7 are not provided with the outlet side temperature sensors in both coolers 11 and 13. ), A discharge temperature sensor (a main return temperature detection sensor) 81 is provided, and an auxiliary return temperature detection sensor 83 is disposed downstream of the downstream cooler 13. These temperature sensors 81 and 83 are connected to the input interface of the showcase side ECU 61.

The operation of the third embodiment is described below.

In the present embodiment, the main return temperature detection sensor 81 is used for temperature control of both coolers 11 and 13 in normal operation. As described above, when the refrigerated showcase 1 is operated for a predetermined time, the showcase side ECU 61 starts defrosting of both coolers 11 and 13 and stops the operation of the compressor 43 and at the same time defrost heaters 71 and 73. Energize The showcase side ECU returns the upstream side cooler 11 from normal defrost to normal operation when the temperature detected by the auxiliary return temperature detection sensor 83 reaches a predetermined value. In this embodiment, the set temperature of the auxiliary return temperature detection sensor 83 is set lower than the set temperature of the main return temperature detection sensor 81. Thus, it becomes possible to control by detecting the temperature of the air which flows in the cooling duct 7, without using the sensor which detects the temperature of the cooler 11,13.

Next, a fourth embodiment will be described.

This configuration is not shown because it is the same as in the third embodiment. In the fourth embodiment, the delay case (not shown) is provided in the showcase side ECU 61, and when the downstream side cooler 13 returns from the defrost to normal operation, a predetermined time elapses, the upstream side cooler 11 ) Is also configured to return to normal operation from the defrost. As a result, defrosting is performed on the upstream side cooler 11 for a long time as compared with the downstream side cooler 13, as in the third embodiment. To allow the cooling wind to flow smoothly.

6 is a longitudinal sectional view of the refrigerating showcase according to the fifth embodiment of the present invention, and FIG. 7 is a front view of the cooler. As shown in these figures, in the refrigerating showcase of the fifth embodiment, a single cooler 91 is provided in the vertical portion of the cooling duct 7. This cooler 91 is divided into an upstream side cooler 93 and a downstream side cooler 95, and the pin pitch of the upstream side cooler 93 is formed to be rougher than the pin pitch of the downstream side cooler 95. As shown in FIG. In addition, the refrigerant is introduced into the upstream side 93a of the upstream side cooler 93 by the refrigerant pipe 97, and is introduced into the downstream side 95a of the downstream side cooler 95 from the downstream side 93b thereof. It is configured to derive to 95b.

According to the configuration of FIG. 7, more frost is generally attached to the upstream side of the downstream cooler 95 in which the pin pitch is narrowly formed. When frost is attached to this part, it blocks the flow path of air. In this embodiment, since the hot refrigerant flows through the coolant pipe 97 after passing through the downstream cooler 95 to which frost is attached, the surface temperature of the fin of this portion is increased. Therefore, since defrosting is suppressed in this part, defrost interval can be lengthened.

Although the description of the specific sealing example is finished, the aspect of the present invention is not limited to these embodiments. For example, in the above embodiments, the present invention is applied to a refrigerated showcase of a multi-stage open type. However, the present invention may be applied to a refrigerated or freezing showcase having a glass window or the like. In the second to fourth embodiments, although a defrost heater is used as the defrosting means, a method such as providing hot gas to the cooler may be used. In addition, the specific configuration of the low temperature showcase, the arrangement of the temperature sensor, and the like may be appropriately changed without departing from the scope of the present invention.

In the invention of Claims 1 to 4, since the defrosting operation of the downstream cooler is terminated earlier than the defrosting operation of the upstream cooler, the cooling operation is enabled by using the downstream cooler returned from the defrosting operation, and the defrosting operation time can be shortened. In addition, since the defrosting operation time of the upstream side cooler is long, the upstream side cooler can be almost certainly defrosted even if a relatively large amount of frost or ice melts and falls to the upstream side cooler. Further, in the invention of claim 5, since the refrigerant heated after passing through the upstream side cooler and the downstream side cooler is led to the upstream side of the downstream side cooler, the fin surface temperature at the most upstream side of the narrowly formed fin pitch of the cooler rises to form the part. This suppresses the effect and makes it possible to lengthen the defrosting inverter.

Claims (5)

In a low temperature showcase having a plurality of coolers arranged in series in a cooling duct of a showcase body and having defrost means for defrosting each cooler, the plurality of coolers arranged in series return from a defrosting operation by the defrosting means to a cooling operation. A low temperature showcase, characterized in that: a return temperature detection sensor for detecting a return temperature is set, and a set temperature of a return temperature detection sensor of a downstream cooler is set lower than a set temperature of a return temperature detection sensor of an upstream cooler. In a low temperature showcase having a plurality of coolers arranged in series in a cooling duct of a showcase body and having defrost means for defrosting each cooler, cooling is performed in a defrost operation of an upstream cooler by the defrosting means in the vicinity of a detection port in the cooling duct. A secondary return for detecting the return temperature for returning to the cooling operation from the defrosting operation of the downstream cooler by the defrosting means near the outlet of the downstream cooler by installing a main return temperature detection sensor for detecting the return temperature for returning to the operation. Low temperature showcase characterized in that the temperature detection sensor is installed. In a low temperature showcase having a plurality of coolers arranged in series in a cooling duct of a showcase body and having defrost means for defrosting each cooler, the defrosting operation of the downstream cooler by the defrosting means in the cooling duct is returned to the cooling operation. It is equipped with a return temperature detection sensor for detecting the return temperature for the return temperature and a delay timer for measuring a predetermined time from the return of the downstream cooler and returning the upstream cooler to the defrost operation at the time indicated by this delay timer. Low temperature showcase. The low temperature showcase according to any one of claims 1 to 3, wherein the defrost means is a defrost heater. In the low temperature showcase in which a plurality of coolers are arranged in series in the cooling duct of the showcase body, the pin pitch of the upstream side cooler is formed to be rougher than the pin pitch of the downstream side cooler, and the liquid refrigerant is introduced to the upstream side of the upstream side cooler. A low temperature showcase, characterized in that it is introduced from the side to the downstream side of the downstream cooler and drawn from the upstream side.