JP2010096447A - Operating method of showcase - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an operating method of a showcase capable of efficiently operating a refrigerating machine even when cooling load is largely changed, and saving energy. <P>SOLUTION: A plurality of coolers 7, 8, 9 of different cooling capacities are disposed in a duct 6 in which cold air is circulated, and the cooler to which a refrigerant is introduced, is selected according to the cooling load from the plurality of coolers. Rotational frequency of a fan 11 for circulating the cold air is changed according to the selected cooler. The cooling load is set on the basis of the information on in-business or not of a shop in which the showcase is disposed, the surrounding environmental information of the showcase, and season information. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a showcase operation method, and more particularly, to a showcase operation method for cooling circulating cold air using a plurality of coolers.

  In an open showcase with an open front of the storage room, it passes through ducts provided at the lower, rear, and upper parts of the storage room, and is blown downward from the outlet provided at the upper front end of the storage room. The inside of the storage room is cooled by covering the front opening of the storage room with a cold air curtain that is sucked into the suction port provided in the storage room and circulates in the lower part of the storage room.

In an open showcase having such a cooling structure, by installing a plurality of coolers in the duct and alternately performing a defrosting operation, temperature fluctuations in the storage chamber during the defrosting operation are suppressed. ing. As a showcase equipped with such a plurality of coolers, a main cooler is arranged on the windward side in the duct, and an auxiliary cooler is arranged on the leeward side, thereby increasing the internal temperature even during the defrosting operation. An open showcase driving method has been proposed (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-23134

  In general, in conventional showcases, coolers and fans are selected according to the daytime load in the summer when the cooling load is the largest, but the load decreases to nearly ¼ at night in the winter. Although the inverter refrigerator and the electronic expansion valve are used to cope with the fluctuation of the cooling load, the operation efficiency of the refrigerator may be reduced at the low load in winter.

  Accordingly, an object of the present invention is to provide a method for operating a showcase that can efficiently operate a refrigerator even when the cooling load changes greatly, and can save energy.

  In order to achieve the above object, according to the method of operating the showcase of the present invention, a storage room having a front surface opened in a main body constituted by a heat insulating wall is formed, and ducts provided at a lower part, a rear part, and an upper part of the storage room. Stored in a cold air curtain that passes through the interior, is blown downward from the outlet provided at the upper front end of the storage chamber, is sucked into the suction port provided at the lower front end of the storage chamber, and is circulated to the lower portion of the storage chamber. In the operation method of the showcase for cooling the storage chamber by covering the opening of the chamber, a plurality of coolers having different cooling capacities are disposed in the duct, and a cooler for introducing a refrigerant is disposed in the plurality of cooling devices. It is characterized in that it is selected from the vessel according to the cooling load.

  Furthermore, in the operation method of the showcase of the present invention, it is preferable to change the rotational speed of the fan for circulating the cold air according to the selected cooler. In addition, the cooling load is set by at least one of information of operating / non-operating information of a store where the showcase is installed, surrounding environment information where the showcase is installed, and seasonal information. It is preferable. Further, the plurality of coolers having different cooling capacities are three coolers having a cooling capacity ratio of 1: 1.8 to 2.2: 3.6 to 4.4, particularly 1: 2: 4. Preferably there is.

  According to the operation method of the showcase of the present invention, by selecting a cooler that introduces a refrigerant from a plurality of coolers having different cooling capacities according to the cooling load, it is possible to deal with a wide range of cooling loads, Since the cool air circulating with the cooling capacity corresponding to the cooling load is cooled, there is no waste and the cooling operation can be performed in a stable state. Therefore, power consumption can be significantly reduced.

  FIG. 1 is a cross-sectional side view showing an example of an open showcase to which the showcase operating method of the present invention can be applied.

  This open showcase 1 is formed with a multistage storage chamber 4 having an open front in a main body 3 constituted by a heat insulating wall 2, and an outer layer duct 5 and an inner layer duct 6 are provided at the lower, rear and upper portions of the main body 3. In addition, three coolers 7, 8, 9 having different cooling capacities are disposed in the inner layer duct 6. The coolers 7, 8 and 9 have a length extending over the entire width of the case, and in the case of this embodiment, the two coolers 7 and 8 are arranged at the front and back, Another cooler 9 is arranged at a predetermined interval. The outer layer duct 5 and the inner layer duct 6 are respectively provided with an outer layer fan 10 and an inner layer fan 11 for circulating cold air in each duct. A defrost heater 12 is provided immediately before the cooler.

  At the upper front end position of the main body 3, a cool air outlet 13 having a honeycomb structure is provided over the entire longitudinal direction of the case, and cool air from the inner and outer ducts is rectified and blown downward as an air curtain from here. The opening is covered and the inside of the storage chamber 4 is cooled. The lower front portion of the main body 3 is provided with a suction port 14 leading to each of the inner and outer ducts, and the cold air sucked by the outer layer fan 10 and the inner layer fan 11 from the suction port 14 becomes the outer layer duct 5 and the inner layer duct. 6 is sent to each.

  The cool air flowing through the outer duct 5 acts as a heat insulating layer, and then blows out from the outlet 13 and circulates to the inlet 14. Further, the cold air flowing into the inner layer duct 6 is cooled by any or all of the coolers 7, 8, 9 to become a cold air having a predetermined temperature, and is blown out from the outlet 13 and circulated in the same manner as described above.

  FIG. 2 is a system diagram showing a refrigeration cycle including the three coolers 7, 8, and 9 having different cooling capacities. The basic configuration of the refrigeration cycle is the same as that of the prior art, and the gaseous refrigerant compressed to high temperature by the compressor 21 is cooled by the condenser 22 to be liquefied and stored in the liquid receiver 23. The refrigerant is expanded by the expansion valve 24, introduced into the coolers 7, 8, and 9 and circulated through the compressor 21.

  In this embodiment, the path from the liquid receiver 23 to each of the coolers 7, 8, 9 is branched into three refrigerant paths 25, 26, 27, and a control panel (not shown) is provided in each branch path 25, 26, 27. Electromagnetic valves 28, 29, and 30 that open and close in response to commands from are provided.

  Therefore, by selecting and opening and closing the three solenoid valves 28, 29, and 30, any or all of the three coolers 7, 8, and 9 can be in a cooled state. For example, when only the first electromagnetic valve 28 is opened, only the first cooler 7 can be brought into a cooled state, and when the second electromagnetic valve 29 and the third electromagnetic valve 30 are opened, the second cooler 8 is opened. And the 3rd cooler 9 can be made into a cooling state.

  The cooling capacity of each of the coolers 7, 8 and 9 can be appropriately selected according to conditions such as the size of the open showcase and the cooling temperature, but in order to cope with a wide range of cooling loads, each cooler 7 , 8, 9 are preferably set so that the ratio of the cooling capacities is 1: 1.8 to 2.2: 3.6 to 4.4.

For example, when the ratio of the cooling capacities of the three coolers 7, 8, and 9 is set to 1: 2: 4, by selecting the three coolers 7, 8, and 9 to be in the cooling state, It is possible to obtain a seven-stage cooling capacity shown in FIG.
1 Cooler 7 only ... Cooling capacity = 1
2 Cooler 8 only ... Cooling capacity = 2
3 Coolers 7 and 8 ... Cooling capacity = 3
4 Cooler 9 only ... Cooling capacity = 4
5 Coolers 7 and 9 ... Cooling capacity = 5
6 Coolers 8 and 9 ... Cooling capacity = 6
7 All coolers 7, 8, 9... Cooling capacity = 7

  Therefore, the optimal cooling operation is performed by appropriately selecting seven stages of cooling capacity from the minimum cooling capacity “1” to the maximum cooling capacity “7” according to the state of the cooling load in the open showcase 1. be able to.

Various factors can be considered for the fluctuation of the cooling load of the open showcase 1, but the cooling load depends on the season, the time zone (business / non-business) and the surrounding environment where the open showcase 1 is installed. It fluctuates greatly. For example, the rate of load change in the four seasons of the day and night in a double air curtain multi-stage case for fresh meat fish is generally as follows, assuming that the daytime in summer is 100.
Summer Midterm Winter Daytime 100 71 52
Nighttime 55 42 27

  In this case, in the open showcase 1 provided with the three coolers 7, 8, and 9, by appropriately setting the cooling capacity of each cooler 7, 8, and 9, for example, in the winter season when the load becomes the smallest Only the cooler 7 having the lowest cooling capacity at night, only the cooler 8 having an intermediate cooling capacity at night in the middle period, two units of the cooler 7 and the cooler 8 at night in the summer and the daytime in winter, and the daytime in the intermediate period The cooling capacity of each cooler 9 is maximized by setting the cooler 9 with the maximum cooling capacity, and by setting all coolers 7, 8, and 9 in the cooling operation state during the daytime in summer when the load is greatest. Obtainable.

  In addition, the surrounding environment where the open showcase 1 is installed, for example, whether it is close to the doorway to the outside or far away, is a major factor in changing the load. The change in product and the frequency of product replacement also affect the load change, so by selecting the cooler to be used according to the change in these cooling loads, efficient cooling can be performed with the optimal cooling capacity. it can.

  In addition, the number of rotations of the motor that drives the fans 10 and 11 forming the air curtain is also changed according to the variation of the cooling load, and is controlled to be high when the cooling load is large and to low when the cooling load is small, The power consumption of the fans 10 and 11 can be reduced, and the cold aisle can be reduced. For example, the rotation speed of the fans 10 and 11 is reduced by 20% in the summer night when the night cover is used with respect to the fan rotation speed in the summer day, and by 20% in the intermediate and winter days, and in the intermediate and winter periods. In the nighttime when using a night cover, the required refrigeration capacity can be reduced and the occurrence of cold aisle can be suppressed without adversely affecting the cooling performance.

  As for the defrosting of the coolers 7, 8, 9, it is necessary to use the defrost heater 12 during the summer day when all the coolers 7, 8, 9 are cooled, Since one of the coolers is in a dormant state, when the cooler in the cooling operation is frosted and needs to be defrosted, it is defrosted by switching the cooler in the dormant state to the cooling operation. Since the off-cycle defrosting can be performed over time by interrupting the cooling operation of the cooler, the power consumption of the defrosting heater 12 can be reduced. Furthermore, by setting the cooling capacity of each of the coolers 7, 8, and 9 with a certain margin, defrosting can be performed without using the defrosting heater 12 even during the daytime in the summer, and the number of parts can be reduced. Energy saving can be achieved.

Next, FIG. 3 is a sectional side view showing another example of an open showcase to which the showcase driving method of the present invention can be applied.
As shown in the open showcase 31 of FIG. 3, three coolers 7, 8, and 9 having different cooling capacities are placed in the inner layer duct 6 at appropriate intervals in the vertical direction over the entire width of the showcase. It can also be arranged. When the coolers 7, 8 and 9 are arranged in the vertical direction in this way, the cooler bracket (side plate) and the aluminum fins are integrated vertically, and only the copper pipe is divided in the vertical direction to flow the refrigerant. .
With this method, the manufacturing cost of the coolers 7, 8, and 9 can be reduced, and even when one of the three coolers 7, 8, and 9 is stopped, the raw air that is not heat-exchanged is blown. There is no blowing from the honeycomb part of the outlet 13.
The ratio of the cooling capacities of the coolers 7, 8 and 9 of the open showcase 31 is the same as the ratio of the cooling capacities of the coolers 7, 8, and 9 shown in FIG. 1, and a system diagram showing the refrigeration cycle is also shown. This is the same as the system diagram shown in FIG. Therefore, the same members are denoted by the same reference numerals, and detailed description based on FIG. 3 is omitted.

  In the present embodiment, an open multi-stage case in which three coolers 7, 8, and 9 having different cooling capacities are described as an example, but the load due to seasons and time is also applied to a flat showcase and a closed showcase. Because of variations, the concept of cooler switching and fan control of the present invention can be applied as well.

  As described above, both the embodiments shown in FIGS. 1 and 3 select and use a plurality of coolers having different cooling capacities according to the load, so that they are optimal even at low loads (during low frequency operation of the inverter refrigerator). Since the degree of superheat (superheat) of the cooler with the cooling capacity can be obtained, the intake gas temperature of the refrigerator is lowered, the increase in the high pressure is suppressed, and more energy-saving operation is possible.

It is a cross-sectional side view which shows one example of an open showcase which can apply the driving method of the showcase of this invention. It is a distribution diagram showing a refrigerating cycle provided with three coolers with different cooling capacities. It is a cross-sectional side view which shows the other example of an open showcase which can apply the driving method of the showcase of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Open showcase 2 Heat insulation wall 3 Main body 4 Storage chamber 5 Outer layer duct 6 Inner layer duct 7, 8, 9 Cooler 10 Outer layer fan 11 Inner layer fan 12 Defrost heater 13 Outlet 14 Suction port 21 Compressor 22 Condenser 23 Receiving liquid 24 Expansion valve 25, 26, 27 Refrigerant path 28, 29, 30 Solenoid valve 31 Open showcase

Claims (5)

A storage chamber with an open front is formed in the main body constituted by the heat insulating wall, passes through the ducts provided at the lower, rear and upper portions of the storage chamber, and downwards from the outlet provided at the upper front end of the storage chamber. Operation of a showcase that cools the storage room by covering the opening of the storage room with a cool air curtain that is blown out toward the suction port provided at the lower front end of the storage room and circulates in the lower part of the storage room In the method
A plurality of coolers having different cooling capacities are arranged in the duct, and a cooler for introducing a refrigerant is selected from the plurality of coolers according to a cooling load. Method.   2. The method of operating a showcase according to claim 1, wherein the number of rotations of the fan for circulating the cold air is changed according to the selected cooler.   The cooling load is set by at least one of information of operating / non-operating information of a store where the showcase is installed, surrounding environment information where the showcase is installed, and seasonal information. The method of driving a showcase according to claim 1 or 2, wherein   The plurality of coolers having different cooling capacities are three coolers having a cooling capacity ratio of 1: 1.8 to 2.2: 3.6 to 4.4. 3. The method for driving a showcase according to any one of 3 above.   The showcase according to any one of claims 1 to 3, wherein the plurality of coolers having different cooling capacities are three coolers having a cooling capacity ratio of 1: 2: 4. how to drive.

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