JP2569896B2 - How to control the temperature inside the open showcase - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the temperature in a refrigerator-circulation open showcase, and more particularly to a method for controlling the temperature inside a refrigerator to be kept substantially constant irrespective of changes in outside air temperature. It relates to a temperature control method.

[Prior art]

FIG. 3 is a cross-sectional view showing a configuration example of a cool air circulation type open showcase. In the figure, 1 is a main body of the open showcase, 2 is an in-compartment display room as a room for displaying products while being cooled, 8 is a product display shelf provided in the display room 2, and 5 is cooling products. An inner blower fan for circulating (inside) cool air around the in-compartment display room 2 in order to maintain the state, 3 is an inside cool-air circulation duct serving as a passage of the inside cool air, and 9A is an in-compartment display room 2 by this inside cool air. An inside air curtain formed on the customer service surface opened to the outside for preventing outside air from entering, an outside blower fan 6 for circulating cool air outside (outside) the inside cool air, and an outside cool air 4 serving as a passage for the outside cool air A circulation duct 9B is an outer air curtain formed on the service surface by the outer cool air, and 7 is a cooler as a heat exchanger for cooling the inner and outer circulating cool air. The cooler 7 is circulated and supplied with a refrigerant cooled by a refrigerator (not shown). As the temperature control method of this open showcase,
The temperature of the (inside) cool air outlet of the cooler 7 is determined by the temperature of a refrigerant supplied to the cooler 7 via a temperature adjusting thermostat (hereinafter abbreviated as temperature adjusting thermostat) (not shown) which operates by detecting the temperature. A method is used in which a predetermined value is maintained by turning on and off an electromagnetic valve for opening and closing the supply path, thereby indirectly maintaining the internal temperature at the predetermined value. The reason for this is that even if the temperature of the interior display room (inside temperature) is directly detected, the shape and arrangement of the product constantly change, and it is difficult to prompt the correct interior temperature. However, due to the structure of the open showcase, the amount of heat of the outside air entering the inside of the refrigerator from the air curtains 9A and 9B is large. When the temperature rises, the inside temperature rises, and when the outside air temperature at night falls, the inside temperature decreases. Therefore, in order to actually keep the temperature inside the open showcase constant, it is necessary to use a lighting signal to prevent the temperature inside the refrigerator from dropping too low during low load at night. The ambient temperature is set higher than the set temperature by a method that unconditionally raises the set temperature above the daytime set value by the set temperature (called a night setback method) or by detecting the ambient temperature of the open showcase (that is, the above-mentioned outside air temperature). When the temperature is lowered, a method of increasing the temperature control thermoset value by a certain set temperature is used.

[Problems to be solved by the invention]

However, the temperature control thermocontrol system as described above has the following problems. First, in the night setback method, which controls with an illumination signal, the temperature control thermo setting value is unconditionally raised by the determined temperature at night, so it is set at night when the ambient temperature is high (summer night). The temperature inside the case rises due to too much change, and the amount of setting change is not enough at night when the ambient temperature is very low, the temperature inside the case is too cold, and the temperature inside the case always keeps constant. It is difficult. Next, with regard to the ambient temperature detection method, when the night cover is attached to the open showcase at night (that is, at night, the cover that covers the opening (service part) of the internal display room 2 for power saving, etc.), this night cover is used. By turning on the air conditioner, the cool air is shut off, the ambient temperature of the case rises, and there is no change in the set value of the temperature control thermostat. However, the inside of the refrigerator becomes too cold due to the night cover. Therefore, an object of the present invention is to provide a method of controlling the temperature inside a refrigerator in an open showcase that can solve this problem.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the method of the present invention comprises the steps of “commodity display cabinet (for example, in-compartment display room 2) for refrigerated storage while displaying the commodities; An opening for serving customers (such as an air curtain 9A), a circulating means (such as a blower fan 5) for circulating cool air around the elegant display room including the opening, and a circulation path for the cool air (duct 3). And a refrigeration unit (such as a cooler 7) that is provided in the refrigeration unit (such as an electromagnetic valve) and cooled by the refrigeration unit so that the temperature of the circulating cold air blown from the heat exchanger is maintained at a set temperature. In an open showcase provided with temperature control means (temperature control thermostat, etc.) for turning on and off the means, the set temperature is varied in accordance with the operation rate of the refrigeration means, and the temperature in the commodity storage is substantially reduced. To keep it constant ”
It shall be.

[Operation]

The operation rate of the refrigerator (that is, the (ON time) of the solenoid valve / (ON
Time + OFF time). Actually, the ON / OFF cycle (ON time + OFF time) of the solenoid valve does not change so much.
Time can be used as a measure of the operation rate. Change the set temperature of the thermostat according to). For example, if the ON time is shorter than the set time, the set value of the temperature control thermo is increased by the adjusted temperature.

【Example】

Hereinafter, an embodiment of the present invention will be described with reference to FIG. 1 and FIG. FIG. 1 shows a temperature set value (vertical axis) of a temperature control thermostat as an embodiment of the present invention versus a refrigerator operating rate (horizontal axis, in which, in this example, the ON time of a solenoid valve is used instead of a strict operating rate). FIG. 2 is a time chart for explaining the operation of the present invention. In FIG. 1, the temperature set value of the temperature control thermo is switched to three ranges of H, M and L in accordance with the operation rate (ON time of the solenoid valve). A, A1, B, B1 ON
The time (minutes) is, for example, when the ambient temperature (open air temperature in Fig. 2) of the open showcase is 17 ° C, 18 ° C, 25 ° C, 26 ° C, and the average air temperature in the refrigerator (one cycle of solenoid valve ON / OFF). Is the ON time for one cycle of the solenoid valve required for cooling to the reference temperature of the open showcase.
When the ON time of the solenoid valve is less than or equal to A minutes, the temperature set value of the temperature control thermo is set to the highest H range, and when it is between A1 minutes and B minutes, the middle M range is set. When the time is more than minutes, the lowest L range is set. In FIG. 2, the horizontal axis represents the time from when the store where the open showcase is installed is opened during the day to when the store is closed again at night and then again when the store is open. Ambient temperature of the case), ON / OFF of the lighting in the open showcase (however, this is also equivalent to no / with night cover), ON / OFF of the in-store lighting,
The temperature of the refrigerator, ON / OFF of the solenoid valve, and the temperature control thermo range are shown. Next, FIG. 2 will be described with reference to FIG. 1. Before the time t1 in FIG. 2, the outside air temperature is high, the heat load of the open showcase is large, and the ON time of the solenoid valve is longer than B minutes. The temperature control thermo range is set to the L range, and temperature control is performed according to a normal thermo set value. Next, when the outside temperature falls and the ON time of the solenoid valve becomes shorter than B at time t1, the set value of the temperature control thermostat is adjusted to the adjustment value ΔT1
The temperature control is performed only by adding to the set value of the temperature control thermostat in the L range (that is, in the M range). The outside temperature further decreases, and at time t2, the solenoid valve turns on.
When the time is shorter than A minutes, the temperature control is performed by adding the set value of the temperature control thermo by the adjustment value ΔT2 to the temperature control set value of the M range (that is, in the H range). Also, the outside temperature drops again, and at time t3, the solenoid valve
When the ON time is longer than A1 minute, the temperature control thermo range is set to H.
The range is switched from the range to the M range, and when the ON time of the solenoid valve exceeds B1 minutes at time t4, the setting range of the temperature control thermo is switched from the M range to the L range.

【The invention's effect】

According to the present invention, the set value of the temperature control thermometer is adjusted according to the operation rate of the refrigerator, for example, in two stages, so that the inside temperature of the refrigerator when the night cover is attached at night in a cold region is prevented from being too cold, Also, by preventing the temperature inside the refrigerator from rising even when the night cover is not used on a summer night, the temperature inside the refrigerator can be kept constant at all times of the day and night, and an open showcase with high freshness management can be provided.

[Brief description of the drawings]

FIG. 1 is a characteristic diagram of temperature control thermosetting as one embodiment of the present invention, FIG. 2 is a time chart for explaining the operation of the present invention, and FIG. 3 is a cross-sectional view showing a configuration example of a cool air circulation type open showcase. FIG. H, M, L: Range, A, A1, B, B1: Operating rate (solenoid valve ON time), Δ
T1, ΔT2: Adjustment value, 2: Internal display room, 3: Inside cool air circulation duct, 5: Inside blower fan, 7: Cooler, 9A inside air curtain.

Claims (1)

(57) [Claims] 1. A merchandise display cabinet for refrigerated storage of merchandise, an opening for customer service to the outside provided in a part of the merchandise display cabinet, and the merchandise display room including the opening. A circulating means for circulating cool air around the heat exchanger, a heat exchanger provided in the cool air circulating path, and cooled by a refrigeration means, and a blowout temperature of the circulating cool air from the heat exchanger to be maintained at a set temperature. In an open showcase provided with a temperature control means for turning on and off the refrigeration means, it is determined whether the ON time of the solenoid valve of the refrigeration means is within a predetermined time,
A method of controlling the temperature in an open showcase, wherein the set temperature is varied according to the time, and the temperature in the product display is kept substantially constant.