JP4231448B2 - Refrigerated showcase - Google Patents

Description

  The present invention relates to a refrigerated showcase that is installed in a counter of a restaurant or the like and that stores stored items while refrigerated, and more specifically, cools a storage room by an evaporator disposed at an upper part and a lower part of the storage room. It is related with the refrigerated showcase comprised so that it might do.

  As a refrigerated showcase for refrigerated storage of articles such as food and beverages, for example, there is a so-called netacase that is installed at a counter in a sushi restaurant and stored refrigerated while exhibiting fresh ingredients such as sushi stored in customers Yes (see Patent Document 1). For example, as shown in FIG. 3, the refrigerated showcase 10 is provided with a storage chamber 14 for storing articles in a refrigerator and a cooling device (cooling system) such as a compressor and a condenser (not shown) for cooling the storage chamber 14. A machine room 16 is provided adjacent to the machine room 16. The storage chamber 14 is defined inside a heat insulating box 12 having a heat insulating structure at the top, sides and bottom, and a glass cover 30 is fitted in the front thereof, and the interior of the storage chamber 14 is It is visible from the front. An article entrance / exit 31 for the storage chamber 14 is opened on the back side of the heat insulating box 12, and slide doors 32, 32 are slidably attached to the article entrance / exit 31, and the slide doors 32, 32 are provided. Is opened and closed to open and close the article entrance 31 to allow the article to be taken in and out of the storage chamber 14 (see FIG. 4).

  As shown in FIG. 4, an upper evaporator 40 connected to the cooling device is disposed in the upper portion of the storage chamber 14 so as to be exposed in the storage chamber 14. Thus, the storage chamber 14 is cooled. Further, a lower evaporator 42 communicating with the upper evaporator 40 is meanderingly disposed on the outer bottom surface of the bottom plate 24 constituting the bottom surface of the storage chamber 14 facing the heat insulating material 18 so as to closely contact the lower evaporator 42. By circulating and supplying the refrigerant, the bottom plate 24 is cooled to indirectly cool the storage chamber 14. In this way, the articles displayed in the storage chamber 14 are cooled from both the upper and lower directions. That is, in the cooling circuit 20 of the refrigerated showcase 10, as shown in FIG. 5, the vaporized refrigerant compressed by the compressor CM is cooled by the fan motor FM in the condenser CD located downstream, and condensed and liquefied. The liquefied refrigerant depressurized by the expansion valve EV via the dryer (moisture remover) 44 becomes a low-temperature vaporized refrigerant by the upper evaporator 40 and the lower evaporator 42, thereby cooling the storage chamber 14 and again returning to the compressor CM. It constitutes a return cycle. Here, the devices constituting the cooling circuit 20 are connected by a refrigerant pipe 46, and the upper evaporator 40 and the lower evaporator 42 are connected in series. In the cooling circuit 20, the refrigerant pipe 46 from the dryer 44 to the expansion valve EV and the refrigerant pipe 46 from both the evaporators 40 and 42 to the compressor CM are brought close to each other in a certain section to exchange heat. The cooling efficiency of the cooling circuit 20 is improved by cooling the liquefied refrigerant flowing toward the expansion valve EV with a relatively low temperature vaporized refrigerant flowing out of the evaporators 40 and 42.

The refrigerated showcase 10 is configured to cool the storage chamber 14 to a predetermined temperature (set temperature) adjusted by the user in accordance with the stored articles and the outside air temperature. By automatically adjusting the temperature in response to the temperature change of the storage chamber 14 due to the above, the storage chamber 14 is maintained at the set temperature. As a method of adjusting the temperature of the storage chamber 14, when the temperature of the storage chamber 14 is higher than a set temperature, the compressor CM is driven and the refrigerant is circulated and supplied to both the evaporators 40 and 42. While the chamber 14 is cooled, on the other hand, when the temperature of the storage chamber 14 is lower than the set temperature, the compressor CM is stopped and the circulation of the refrigerant is stopped to prevent overcooling of the storage chamber 14. Here, in the upper evaporator 40 exposed and disposed in the storage chamber 14, the moisture in the storage chamber atmosphere becomes dew and attaches to the upper evaporator 40 during the cooling operation, and this is attached to the upper evaporator 40. As it progresses, it freezes and forms frost, covering the surface of the upper evaporator 40. That is, when the cooling operation is stopped for temperature control, the frost adhering to the upper evaporator 40 may be melted and the molten water may be dripped onto the stored article.
JP 2000-139633 A

  Therefore, regardless of the temperature of the storage chamber 14, the compressor CM is controlled to be continuously operated, and a constant pressure expansion valve is used as the expansion valve EV to adjust the flow rate of the refrigerant so that the outside air temperature can be reduced. There is also a temperature control method that allows the storage chamber 14 to be kept at a set temperature even if it changes. However, in the temperature control method using this constant pressure expansion valve, the expansion valve EV is opened and closed in accordance with the pressures of both evaporators 40 and 42, so that it cannot follow a large change in the outside air temperature. For example, if the set temperature of the storage chamber 14 is adjusted to a low temperature range, the stored articles can be suitably cooled even when the outside air temperature becomes high, but when the outside air temperature falls, There is a possibility that the temperature of the storage chamber 14 is excessively lowered and the article is supercooled, and the article is damaged by freezing or the like. On the other hand, if the set temperature of the storage chamber 14 is set to a high temperature range, it is pointed out that the stored article cannot be sufficiently cooled when the outside air temperature rises, and the deterioration of the article is accelerated. The That is, it is necessary for the user to frequently adjust the temperature of the storage chamber 14 according to the outside air temperature, which is complicated.

  Further, like the refrigerated showcase 10 disclosed in Patent Document 1, a water drop receiving tray 70 for receiving molten water is provided below the upper evaporator 40, and a structure in which molten water does not drip on the stored article is proposed. Yes. However, by providing the water droplet tray 70, not only does the water droplet tray 70 block the light taken in through the glass cover 30 and deteriorates the visibility, the display property of the stored articles is deteriorated. There is an adverse effect that the circulation of the atmosphere in the storage room, which is cooled by the heat exchange by the evaporator 40, is hindered and the cooling efficiency is lowered. Moreover, inconveniences such as a reduction in the indoor space of the storage chamber 14 and the complicated cleaning of the water droplet tray 70 are pointed out.

  That is, the present invention has been proposed in order to suitably solve these problems inherent in the refrigerated showcase according to the prior art, and the molten water may be dropped from the upper evaporator onto the stored article. An object of the present invention is to provide a refrigerated showcase that can suitably adjust the temperature of the storage room.

In order to overcome the above problems and achieve the intended purpose, the refrigerated showcase according to the present invention includes:
The upper evaporator provided above the article storage chamber and the lower evaporator provided at the lower portion of the storage chamber are connected to a cooling system, and the refrigerant is circulated and supplied to both evaporators from the cooling system to cool the storage chamber. In the refrigerated showcase,
The upper evaporator and the lower evaporator are connected in parallel to the cooling system, and a pipe opening / closing means is provided in a refrigerant supply pipe connected to the cooling system by the lower evaporator,
In a state where the supply of the refrigerant to the upper evaporator is continued, the pipe opening / closing means is opened and closed to supply or shut off the refrigerant to the lower evaporator.

  According to the refrigerated showcase of the present invention, the upper evaporator and the lower evaporator are connected in parallel to the cooling system, and the pipe opening / closing means that opens and closes to supply or shut off the refrigerant to the lower evaporator is provided to the lower evaporator. Since the refrigerant is always supplied to the upper evaporator even during the control of supply and stop of supply of the refrigerant to the lower evaporator, the cooling state is interrupted. In other words, the frost attached to the upper evaporator is not melted and the stored article is not soiled. In addition, since the pipe opening / closing means is automatically operated according to the temperature detected by the temperature detecting means for detecting the temperature of the storage chamber, it is confirmed that the temperature of the storage chamber has dropped below a predetermined temperature during the cooling operation. When the temperature detecting means detects, the pipe opening / closing means is closed and cooling by the lower evaporator is stopped, and when the temperature detecting means detects that the temperature of the storage chamber has risen above a predetermined temperature, the pipe opening / closing means is opened. By restarting the cooling of the storage chamber by the lower evaporator, the temperature of the storage chamber can be automatically adjusted. Furthermore, when the temperature of the storage chamber is higher than the set temperature, the temperature of the storage chamber can be quickly lowered by cooling with both evaporators, and deterioration of stored items can be suppressed, and the temperature of the storage chamber can be reduced. When the temperature is lower than the predetermined temperature, the lower evaporator is stopped and cooled only by the upper evaporator, thereby avoiding problems such as freezing due to overcooling of the stored items, and the efficiency at which the temperature of the storage chamber can be kept constant Cooling operation can be implemented. In addition, since molten water does not drip from the upper evaporator, there is no need to provide a water tray, and the display performance of articles stored in the storage room is impaired, the circulation of cold air is hindered, cooling efficiency is reduced, and the indoor space There is no inconvenience such as a decrease.

  Next, the refrigerated showcase according to the present invention will be described below with reference to the accompanying drawings by way of preferred examples. For convenience of explanation, the same components as those of the refrigerated showcase shown in FIGS. 3 to 5 are denoted by the same reference numerals and detailed description thereof is omitted.

  As shown in FIG. 1, in the refrigerated showcase 11 according to the embodiment, the storage room 14 for storing refrigerated items such as fresh foods and beverages has a heat insulating material 18 such as urethane foam between an inner box 22 and an outer box 26. The inside of the heat insulation box 12 filled with is defined. A glass cover 30 made of transparent multilayer glass is fitted on the front side of the storage chamber 14, that is, on the front side of the heat insulating box 12 that faces the customer when the refrigerated showcase 11 is placed on a counter or the like. The articles stored in the storage chamber 14 can be confirmed from the front. On the other hand, an article entry / exit 31 is opened on the back side of the heat insulating box 12 and the article entry / exit 31 has sliding doors 32 and 32 held vertically by rails 34 and 35 slid in the left and right direction. The article doorway 31 can be freely opened and closed. The bottom surface of the storage chamber 14 is inclined downward from the slide door 32 side toward the glass cover 30 side, and articles are displayed on a base (not shown) such as a scissors placed on the bottom surface. This makes it easy to see the finished article from the front side. A drainage port 36 is provided on the inclined lower end (glass cover 30) side of the bottom surface, and the water accumulated in the storage chamber 14 is drained from the refrigerated showcase 11 through a drainage pipe 38 connected to the drainage port 36. To be discharged.

  A cooling device (cooling system) that cools the storage chamber 14 is disposed in a machine chamber 16 that is internally defined in a cabinet that is integrally disposed adjacent to the heat insulating box 12, and includes a compressor CM and a condenser. It comprises a device CD, a fan motor FM, expansion valves EV1, EV2, etc. (see FIG. 2). An upper evaporator 40 connected to the cooling device is arranged in a meandering manner extending in the width direction at the upper part of the storage chamber 14, and the refrigerant is circulated and supplied to the upper evaporator 40, so that the atmosphere in the storage chamber is increased. The storage chamber 14 is cooled directly by cooling. Further, a lower evaporator 42 connected to the cooling device is arranged in a meandering manner on the outer bottom surface facing the heat insulating material 18 side of the bottom plate 24 constituting the bottom surface of the storage chamber 14, and the lower evaporator 42 is attached to the lower evaporator 42. By circulating and supplying the refrigerant, the bottom plate 24 is cooled to indirectly cool the storage chamber 14. As described above, the articles displayed in the storage chamber 14 are cooled from both the upper and lower directions by the evaporators 40 and 42 disposed above and below the storage chamber 14 during the cooling operation.

  The refrigerated showcase 11 is provided with temperature detecting means Th such as a thermostat for detecting the temperature in the storage chamber 14 and controlling opening and closing of an electromagnetic valve SV as a pipe opening / closing means described later. In terms of an electric circuit, for example, the contact of the electromagnetic valve SV and the temperature detecting means Th arranged in series on the circuit is closed in accordance with the detection of the set temperature, and the electromagnetic valve SV is energized. A plunger that has opened the pipe by the flow of electricity through the coil of the solenoid valve SV closes the pipe and blocks the refrigerant flow. Further, the position where the temperature detection means Th is attached is not particularly limited as long as it is a position that does not get in the way of the inside of the storage chamber 14 and does not get in the way and is hardly affected by the temperature other than the storage chamber 14. Further, an electrical component (not shown) for controlling the operation of the cooling device is disposed in the machine room 16, and based on the detection result of the predetermined temperature (set temperature) of the temperature detection means Th, The electromagnetic valve SV is automatically controlled to be opened and closed, and controlled to operate each device constituting the cooling device by operating an operation switch provided on a control panel (not shown). The control panel is also provided with an operation unit for adjusting the set temperature of the temperature detecting means Th.

  As shown in FIG. 2, the refrigerated showcase 11 of the embodiment includes a compressor CM, a condenser CD, a fan motor FM, a dryer (moisture remover) 44, a first expansion valve disposed in the machine room 16. A cooling device such as EV1, a second expansion valve EV2, a solenoid valve SV, and the like, and an upper evaporator 40 and a lower evaporator 42 provided on the storage chamber 14 side are connected to each other through a refrigerant pipe 46. A cooling circuit 50 is configured to allow the refrigerant to circulate. That is, in the cooling circuit 50, the vaporized refrigerant compressed by the compressor CM is condensed and liquefied by the condenser CD via the refrigerant pipe 46, and moisture contained in the refrigerant is removed by the dryer 44, and then the first expansion valve EV1. And the second expansion valve EV2 are depressurized, and are both expanded and evaporated in the upper evaporator 40 and the lower evaporator 42 at once, whereby both evaporators 40 and 42 are forcibly cooled to exchange heat with the storage chamber 14. And the storage chamber 14 is cooled. The vaporized refrigerant evaporated by the upper evaporator 40 and the lower evaporator 42 is configured to repeat a cycle of returning to the compressor CM via the refrigerant pipe 46. In addition, the code | symbol FM in a figure shows the fan motor which is drive | operated at the time of cooling operation and air-cools condenser CD.

  In the cooling circuit 50, the upper evaporator 40 and the lower evaporator 42 are connected in parallel to the cooling device and include expansion valves EV1 and EV2 corresponding to the upstream side (upstream side in the refrigerant flow direction). (See Figure 2). Specifically, the refrigerant pipe 46 is branched downstream of the dryer 44 and is divided into a first path R1 connected to the upper evaporator 40 and a second path (refrigerant supply pipe) R2 connected to the lower evaporator 42. Goodbye In the state where the first expansion valve EV1 is disposed in the first path R1 and the compressor CM is driven (during the cooling operation of the refrigerated showcase 11), the refrigerant always passes through the first expansion valve EV1. It is supplied to the upper evaporator 40. On the other hand, in the second path R2, the solenoid valve SV and the second expansion valve EV2 are disposed from the upstream side, and the refrigerant is driven by the solenoid valve SV and the second expansion when the compressor CM is driven. The lower evaporator 42 is supplied via the valve EV2. The electromagnetic valve SV is automatically controlled to open and close based on the temperature detection of the storage chamber 14 by the temperature detection means Th. That is, when the temperature of the storage chamber 14 is higher than the set temperature, the solenoid valve SV is opened to allow the circulation of the refrigerant to the second path R2, and when the temperature of the storage chamber 14 is lower than the set temperature, The solenoid valve SV is closed to block the circulation of the refrigerant to the second path R2. Then, the refrigerant pipes 46 and 46 connected to the discharge sides of the upper evaporator 40 and the lower evaporator 42 are joined again on the upstream side of the compressor CM, and the vaporized refrigerant heat-exchanged by both the evaporators 40 and 42 is the compressor. It flows into the CM. Therefore, in the refrigerated showcase 11, the storage chamber 14 is always cooled by the upper evaporator 40 during the cooling operation, and the cooling state of the lower evaporator 42 by the opening / closing operation of the electromagnetic valve SV based on the temperature detection of the temperature detection means Th is performed. The temperature of the storage chamber 14 can be adjusted by turning on and off.

(Effects of Example)
Next, the operation of the refrigerated showcase according to the embodiment will be described. When the operation switch of the control panel is turned on, the refrigerated showcase 11 drives the compressor CM and starts circulating the refrigerant in the cooling circuit 50. At the same time, the fan motor FM is rotationally driven to start cooling the condenser CD with air. The storage chamber 14 is gradually cooled by heat exchange with the evaporators 40 and 42 that are forcibly cooled by the vaporized refrigerant supplied to the upper evaporator 40 and the lower evaporator 42. Note that the set temperature is adjusted in advance according to the article stored in the storage chamber 14 and the outside air temperature by an operation unit for adjusting the temperature detection means Th in the control panel.

  When the cooling operation proceeds and the temperature of the storage chamber 14 reaches the set temperature and further decreases, it is detected that the temperature detecting means Th has decreased from the set temperature, and the second path R2 is detected based on this temperature detection. The electromagnetic valve SV inserted in is closed. Thereby, the supply of the refrigerant to the second path R2 is interrupted, and the cooling of the storage chamber 14 by the lower evaporator 42 is stopped. On the other hand, since the circulation of the refrigerant is continued in the first path R1 that is in parallel with the second path R2, the cooling of the storage chamber 14 by the upper evaporator 40 is continued. When the cooling by the lower evaporator 42 is stopped, the temperature drop of the storage chamber 14 that has fallen due to the cooling by both evaporators 40 and 42 stagnate, and overcooling of the storage chamber 14 is prevented. Further, since the storage chamber 14 is continuously cooled by the upper evaporator 40, the inflow of outside air by opening and closing the slide doors 32, 32 and the glass cover 30 and the slide doors 32, 32 defining the storage chamber 14. In addition, the temperature rise of the storage chamber 14 caused by the outflow of a minute cold air from the heat insulating box 12 can be suppressed, and compensation can be made so that the storage chamber 14 has a constant temperature. Furthermore, the continuous cooling by the upper evaporator 40 provides a buffering action against a sudden rise in the outside air temperature and prevents the stored articles from deteriorating without the temperature of the storage chamber 14 rising rapidly. obtain. Even if continuous cooling is performed by the upper evaporator 40, there is no possibility that the storage chamber 14 shifts to a supercooled state.

  When the temperature of the storage chamber 14 rises above a set temperature due to fluctuations in the outside air temperature or frequent opening and closing of the slide doors 32, 32, the temperature detecting means Th detects that the temperature has risen above the set temperature. Based on the temperature detection, the electromagnetic valve SV inserted in the second path R2 is opened. Thereby, the supply of the refrigerant to the second path R2 is restarted, and the cooling of the storage chamber 14 by the lower evaporator 42 is started. That is, when the temperature of the storage chamber 14 is higher than the set temperature, the storage chamber 14 can be cooled by both evaporators 40 and 42, thereby quickly reducing the temperature of the storage chamber 14, thereby suppressing deterioration of the stored articles. When the temperature of the storage chamber 14 is lower than the set temperature, the lower evaporator 42 is stopped and cooled only by the upper evaporator 40, thereby avoiding problems such as freezing due to overcooling of the stored articles, and the storage chamber An efficient cooling operation capable of keeping the temperature of 14 constant can be performed. Further, since the electromagnetic valve SV is opened and closed based on the temperature detection of the storage chamber 14 by the temperature detection means Th as compared with the temperature adjustment by the constant pressure expansion valve described in the conventional example, the temperature fluctuation of the storage chamber 14 On the other hand, since the temperature adjustment by the lower evaporator 42 can respond immediately, the followability with respect to fluctuations in the outside air temperature is good, and adverse effects such as overcooling and deterioration of the stored articles can be avoided.

  In this way, in the cooling circuit 50, the upper evaporator 40 and the lower evaporator 42 are connected in parallel, so even if the second path R2 to which the lower evaporator 42 is connected is closed by the electromagnetic valve SV, The refrigerant is continuously supplied to the upper evaporator 40 connected to the first path R1 during the cooling operation. That is, regardless of the temperature change of the storage chamber 14, the cooling state of the upper evaporator 40 is not interrupted. Therefore, even if frost adheres to the upper evaporator 40, the frost does not melt during the cooling operation. The melted water does not drip into the housed article and cause it to foul. Therefore, as described in the conventional example, it is not necessary to provide means for receiving the molten water such as the water drop tray 70 below the upper evaporator 40, so that the display property of the articles stored in the storage chamber 14 is not impaired. In addition, the indoor space of the storage chamber 14 can be used effectively, and cleaning can be suitably performed. Furthermore, since a time zone for stopping the cooling by the lower evaporator 42 is provided, an excessive decrease in the humidity of the storage chamber 14 is suppressed, so that the stored articles can be made difficult to dry.

  In the refrigerated showcase 11 of the embodiment, the expansion valves EV1 and EV2 are used on the upstream side of the evaporators 40 and 42 as means for maintaining the pressure difference between the evaporators 40 and 42 and the cooling device. Instead, a capillary tube provided corresponding to each of the evaporators 40 and 42 may be employed. Further, although the electromagnetic valve SV is used as the pipe opening / closing means of the second path R2, for example, an electric valve can be adopted as long as the pipe can be opened and closed based on the temperature detection of the temperature detection means Th. . In the cooling circuit 50 of the embodiment as well, the refrigerant pipe 46 that goes from the dryer 44 to the expansion valves EV1 and EV2 and the refrigerant pipe 46 that goes from both the evaporators 40 and 42 to the compressor CM are close to each other in a certain section. By cooling or providing a heat exchanger, the liquefied refrigerant flowing from the dryer 44 toward the expansion valves EV1 and EV2 is cooled by the cold vaporized refrigerant flowing out of the evaporators 40 and 42 to cool the cooling circuit. Efficiency can be improved.

1 is a side sectional view showing a refrigerated showcase according to a preferred embodiment of the present invention. It is the schematic which shows the cooling circuit of the refrigerated showcase of an Example. It is a schematic perspective view which shows the conventional refrigerated showcase from the front side. It is AA sectional drawing of FIG. It is the schematic which shows the cooling circuit of the conventional refrigerated showcase.

Explanation of symbols

14 storage room, 40 upper evaporator, 42 lower evaporator,
CM compressor (cooling system), CD condenser (cooling system), EV1 first expansion valve (cooling system),
EV2 second expansion valve (cooling system), R2 refrigerant supply line (second path),
SV solenoid valve (pipe opening / closing means), Th temperature detection means

Claims (2)

The upper evaporator (40) provided above the article storage chamber (14) and the lower evaporator (42) provided at the lower part of the storage chamber (14) are connected to the cooling system (CM, CD, EV1, EV2). In the refrigerated showcase that cools the storage chamber (14) by circulating the coolant from the cooling system (CM, CD, EV1, EV2) to both evaporators (40, 42),
The upper evaporator (40) and the lower evaporator (42) are connected in parallel to the cooling system (CM, CD, EV1, EV2), and the lower evaporator (42) is connected to the cooling system (CM, CD, EV1, EV2). ) Is provided with a pipe opening / closing means (SV) in the refrigerant supply pipe (R2) connected to
In a state where the supply of the refrigerant to the upper evaporator (40) is continued, the pipe opening and closing means (SV) is opened and closed to supply or shut off the refrigerant to the lower evaporator (42). Characterized refrigerated showcase. The refrigerated showcase according to claim 1, wherein the pipe opening / closing means (SV) automatically operates according to a temperature detected by a temperature detecting means (Th) for detecting the temperature of the storage chamber (14).

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