JPS63263377A - Defrostation method in cooling showcase and device thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a defrosting method and device for a cooling showcase, and particularly to a defrosting method and device for a cooling showcase that can prevent the temperature of products from increasing due to defrosting. Regarding.

[Conventional technology]

For cooling showcases such as refrigerated open showcases,
Products to be refrigerated are displayed on a display shelf, and the products are cooled by a cooler disposed inside a cooling case.

In this cooling showcase, defrosting of the cooler is conventionally performed as follows.

Defrosting methods include a single-heater method, which defrosts by energizing a defrosting heater, and a two-hot gas method, which defrosts by passing hot gas through a cooler. The defrosting intervals are kept at constant intervals by the tires. Further, one defrosting time is set by a timer to a length that ensures that defrosting of the cooler is completed.

In addition, when defrosting is performed by so-called demant defrosting,
Defrosting can be done by changing the defrosting interval by detecting frost build-up on the cooler or by detecting environmental conditions such as temperature around the case, which are factors related to the amount of frost on the cooler. I'm trying to frost it. In addition, IIn is not set by a timer during one defrosting operation, but the temperature of the cold air outlet of the case is detected by utilizing the fact that the temperature of the cold air outlet of the case rises rapidly when defrosting is completed. However, there is also a method of stopping defrosting when this temperature reaches a certain level (5).

(Problem that the invention seeks to solve) By the way, with such traditional defrosting methods.

For example, defrosting is performed day and night using the same method, and the defrosting is set to be performed once until defrosting is reliably completed, and this defrosting is repeated periodically. As shown in Figure 8, especially during the daytime when the store is open (Vo period), the temperature inside the showcase decreases W2 every time it is defrosted.
begins to rise significantly. Note that the v11 period indicates that the store is closed. So conventionally.

There is a problem in that as the temperature inside the case increases, the temperature W1 of the products on display also increases.

Therefore, the present invention was proposed to solve these conventional problems, and is a cooling method that can prevent the temperature of the products in the showcase from rising when the cooler is defrosted, and can efficiently cool the products. Defrosting method in showcase and its!
The purpose is to provide eat.

[Means for solving problems]

In order to achieve this objective, the defrosting method for a cooling showcase of the present invention defrosts the cooler installed in the cooling showcase during the opening or closing, during the daytime or at night, or during the daytime or nighttime. The feature is that defrosting is performed by changing the defrosting stop temperature in response to changes in conditions such as summer or winter. Also, the device may be open or closed, or during the day or at night.

Alternatively, a selection circuit is provided that selects one defrosting method from among a plurality of defrosting methods having different defrosting stop temperatures by being supplied with a signal that identifies a change in the situation such as summer or winter; A configuration including a defrosting section vJ circuit that outputs a defrosting drive signal for executing defrosting using a designated defrosting method by being supplied with a defrosting method designation signal output from the selection circuit. It becomes.

[Effect]

In the present invention described above, defrosting can be performed by changing the defrosting stop temperature according to changes in the situation. Therefore, during opening hours when the cooling showcase is in operation, or during the summer season! [By defrosting the cooler by setting the end temperature low, it is possible to prevent a rise in the air temperature in the case due to defrosting, and to suppress the rise in temperature of the displayed products.

(Example) Hereinafter, an example of the defrosting method and device for a cooling showcase according to the present invention will be described in detail.

First, to explain the defrosting method according to the present invention, in the present invention, defrosting is performed by changing the defrosting stop temperature according to changes in the situation. During the opening of the store, the cooler provided in the cooling showcase is defrosted, for example, using an off-cycle method, and the defrosting stop temperature is set low to perform defrosting. Defrosting using this off-cycle method is
This method performs defrosting simply by stopping the cooling operation of the cooler, and the cooling showcase is, for example, an open refrigerator box.
If it is a case, the heat load is large because the opening of the showcase is open while the store is open, and the off-cycle method can be used to remove frost.

Also, if you try to defrost using the off-cycle method while the store is open,
Set the defrosting stop temperature to a low value so that defrosting is stopped at a low temperature.

Also, while the store is open, the period from when defrosting stops until the time of defrosting is set short, and the number of times defrosting is increased.

In this way, even if you set the defrost stop temperature low, the defrost interval is short and the frost can be removed little by little.
The cooler will not suffer from cooling failure due to frost formation.

By doing this, the temperature rise inside the showcase due to defrosting can be kept low, and many products can be displayed.
Even when the store is open, when the lights in the showcase are turned on and the temperature of products tends to rise due to radiant heat, it is possible to cool the displayed products without raising their temperature, which has a great effect on maintaining the freshness of the products.

Similarly, in the summer, the same effect can be obtained by defrosting by setting the defrosting stop temperature low as described above.

In addition, when the store is closed and there are few products on display, it can be linked to the light switch in the showcase or by a schedule timer to switch from the off-cycle defrosting method during store openings to forced defrosting using a single heater. This is because defrosting cannot be performed reliably by setting a high stop temperature. This one-heater defrosting method defrosts the cooler by supplying electricity to a heater provided near the cooling coil. -0- Also, when defrosting while the store is closed, set the defrost end temperature higher than when the store is closed to ensure that the cooler is defrosted. is set longer than when the store opens.

When the store is closed, the lights in the showcase are turned off and the openings are covered with curtains and heat insulating boards as described above, so the temperature of the products is low, and even with defrosting in this way, the temperature of the products does not rise much.

Also, in winter, unlike in summer, efficient defrosting can be performed by setting the defrost stop temperature high.

Next, a defrosting device will be explained in order to carry out the defrosting method according to the present invention described above.

FIG. 1 is a block circuit diagram of a defrosting device according to the present invention.

In the figure, one of several defrosting methods is selected depending on whether the store is open (mainly during the day) when the cooling showcase is in operation or closed (mainly at night) when the cooling showcase is stopped. A selection circuit 1 for selecting a defrosting method receives from an input terminal 2 an identification signal a indicating whether the lighting switch 33 for the fluorescent tube 35 that illuminates the inside of the cooling showcase is on or off, and also inputs a schedule for opening and closing the store. A schedule timer signal is input from the schedule timer 3 in which the schedule timer 3 is stored. In this selection circuit 1, based on the input of the identification signal a or the schedule timer signal S, a selection signal C1 of the first defrosting method, which is a defrosting method when the store is open, or a defrosting method when the store is closed, for example. A second defrosting method selection signal d is generated, and these selection signals C or d are supplied to the defrosting control section 4.

This defrosting control unit 4 receives a defrosting cycle signal e from a defrosting cycle timer 5 that generates a defrosting cycle signal e that determines the defrosting repetition cycle X^ in the first defrosting method during opening, for example. At the same time, a defrosting cycle signal f is also supplied from a defrosting cycle timer 6 that generates a defrosting cycle signal f that determines the defrosting repetition cycle XB in the second defrosting method during, for example, a store being closed. Here, X^<Xe.

be.

Further, a detection output g of a temperature sensor 7 that detects the temperature of the cold air blown out is supplied to an analog fist digital converter (A/D converter) 8. This sensor 7 is provided at the cold air outlet 3 as shown in FIG. Further, for example, a defrost stop temperature setting signal is input to the A/D converter 8 from the setting unit 1O that can set the defrost stop temperature T^ (for example, about +3°C) during the opening of the store in the first defrost method. For example, the setting section l! can set the defrosting stop temperature Tn (for example, about +10°C) in the second defrosting method while the store is closed.
From then on, the defrost stop temperature setting signal i is input to the A/D converter 8, where it is set so that T<Ta.

The A/D converter 8 converts the detection output g and the setting signals I and I into digital signals (detection signal G, 'setting signals H and I), and sends these signals G, H and I to the comparison circuit 12. supply to. The comparison circuit 12 generates comparison outputs j and k to determine whether the detection signal G exceeds the setting signals H and I.

These comparison outputs J and k are supplied to the defrosting stop signal sending circuit 3.

The sending circuit 13 sends a defrosting execution signal in the first defrosting method during store opening to the defrosting system g4 unit 4 when T≧T^, and when T≧Te. For example, a defrosting stop signal m is sent to the defrosting control unit 4 using the second defrosting method during closing.

In the defrosting control s4, a defrosting execution signal n for executing the first defrosting method is generated based on each input signal, for example, while the store is open.
For example, during closing, a defrosting execution signal 0 for executing the second defrosting method is generated, and these defrosting execution signals n or 0 are supplied to the defrosting drive signal output section 14.

Here, for example, the defrosting execution signal n that is output while the store is open is a pulse signal that rises in response to the defrosting cycle signal e with period X^ in positive logic and falls in response to the defrosting execution signal statement output when T≧TA. It has become. Further, for example, the defrosting execution signal O outputted while the store is closed is a pulse signal that rises in response to the defrosting period signal f having a cycle XB and falls in response to the defrosting end signal m outputted when T≧TB.

The defrost drive signal output unit 14 outputs a speed increase signal p that speeds up the inner layer fan motor 15 based on the input of the defrost execution signal n during opening, for example, and outputs a stop signal q that stops the outer layer fan motor 16. , and pipe 1 for refrigerant
Outputs an off signal r to turn off the solenoid valve 17 provided at the valve 9. As a result, while the store is open, defrosting is performed at a low defrosting stop temperature using the off-cycle method of the first defrosting method.

For example, when the store is closed, based on the input of the defrosting execution signal 0, the speed increase signal p, the stop signal q, and the off signal r are outputted, and an energization signal is sent to energize the defrosting heater 18. Output S. As a result, while the store is closed, defrosting is performed at a high defrosting stop temperature using the second defrosting method, for example, one heater type.

Here, the inner layer fan motor 15 is a motor that drives an inner layer fan 23 that blows air to a cooler 22 provided with a cooling coil 21, and the outer layer fan motor 16 is a motor that drives an air curtain 28 at an opening 25 of a refrigerated open case 24. This is a motor that drives the outer layer fan 27 that produces the outer layer. Further, the solenoid valve 17 is used to turn on and off the supply of refrigerant to the cooling coil 21. Further, the heater 18 is located between the cooler 22 and the inner layer fan 23, for example, the cooler 22.
It is located at the bottom of the .

By the output from the defrosting drive signal output section, the air blowing state 8 (indicated by the arrow) during cooling shown in Fig. 2 is changed to the air blowing state shown in Fig. 3 during defrosting during opening of the store. fJJ during closing when the opening 25 is covered by the cover 28 of
The air blowing state can be changed as shown in Figure 4.

In the above-mentioned defrosting device configured in this way, during the opening period indicated by Vo as shown in Fig. 5, defrosting can be performed in small steps at a cycle of X^ using a low defrosting temperature using an off-cycle method. Product temperature W+ of products displayed on display shelf 23
The upper A can be kept lower than in the past. Note that W2 in FIG. 5 indicates the air temperature inside the refrigerator.

Also, during the period when the store is closed, indicated by VN, defrosting is performed, for example, by one heater type, and the defrosting cycle It's higher than the temperature.

In the above explanation, we explained how to defrost by selecting different defrosting methods depending on whether the store is open or closed. Explain the operation of frosting.

In FIG. 1, a selection circuit 1 is supplied with a detection output t from a sensor 30 that detects the temperature and humidity inside the store, and
An operating rate signal U representing the operating rate of the refrigerator connected to the cooler 22 is supplied from an input terminal 31 . For example, in summer, the temperature and humidity inside a store rise, and the operating rate of the refrigerator increases. Therefore, the selection circuit 1 selects the above-mentioned first defrosting method based on the detection output t and the operating rate signal U. A selection signal C to be selected is output. As a result, in the summer, the defrosting stop temperature is low and the defrosting cycle is set short, allowing defrosting to be performed using an off-cycle method, for example, which suppresses the rise in temperature of displayed products due to defrosting, and efficiently cools the products. can be done.

On the other hand, in winter, for example, a selection signal d for selecting the above-mentioned second defrosting method is output from the selection circuit 1 based on the detection output t and the operation rate signal U. As a result, in winter when the environmental temperature drops, unlike in summer, defrosting is performed using, for example, a single heater.

Next, another embodiment will be described based on FIGS. 6 and 7.

In the figure, a fluorescent light ballast 34 is connected to the AC power source 32 in series with a lighting switch 33, and a fluorescent lamp 35 used for illuminating the heavy case 24 is connected to the ballast 34. Note that the reference numeral 38 is a glow starter. Further, a relay 37 is connected to the ballast 34 in parallel to the switch 33 side. A temperature sensor 38 is connected to the normal oven contact 37a of the relay 37 on the outlet side of the cooler 22.
The normally closed contact 37b of the relay 37 is connected to a high temperature set thermostat 41 equipped with a temperature sensor 4◎ on the outlet side of the cooler 22. Normally open contact 3 above? The other end of a and the other end of the low temperature set thermostat 39 are connected to a defrost timer 42 that sets the defrost repetition cycle, and the normally closed contact 3
? The other end of b and the other end of the high temperature set thermostat 41 are connected to a defrost timer 42. Further, this defrosting timer 42 is connected to a defrosting drive circuit (not shown), and based on the output of this timer 42, for example, a defrosting repetition cycle in heater defrosting is set.

In the M removal device having this configuration, when the lighting switch 33 is turned on when the store is opened, the relay 37 is energized, and the contact 3? a closes and contact 37a opens.

As a result, the transmission of the timer output of the defrost timer 42 is controlled based on the drive of the low temperature set thermostat 39 that sets the defrost stop temperature while the store is open, and defrosting is performed at a low defrost stop temperature while the store is open. . When the store is closed, the light switch 33 is turned off, and the output of the timer output of the defrost timer 42 is controlled based on the drive of the high-temperature set thermostat 41 by an operation opposite to the above-mentioned operation. Defrosting is performed depending on the stop temperature.

Here, the timer output output from the defrost timer 42 is
(2) Instead of an output, two outputs may be used, one for opening and one for closing, and defrosting may be performed at a shorter defrosting repetition cycle during opening than during closing.

As explained above, with the defrosting device of this embodiment, it is possible to perform defrosting by selecting different defrosting methods with different defrosting stop temperatures during store opening and closing, and to perform defrosting at a low defrost temperature during store opening and closing. Since defrosting can be performed at the frost stop temperature, the temperature of displayed products can be prevented from rising and cooling can be carried out efficiently.

Note that, as the second defrosting method, defrosting may not be performed using a single heater method, but may be performed using a hot gas method.

(Effects of the Invention) As explained above, in the present invention, defrosting is performed by changing the defrosting stop temperature according to changes in the situation.Therefore, while the store is open, defrosting is performed by, for example, an off-cycle method. By setting the defrost end temperature low and shortening the defrost repetition cycle to defrost in small increments, the rise in air temperature inside the showcase due to defrosting can be suppressed.
It is possible to prevent the temperature of products displayed in the showcase from rising.

This allows the products to be efficiently cooled and has a significant effect on maintaining the freshness of the products. In addition, defrosting is performed using an off-cycle method while the store is open, which saves labor and energy for defrosting.

In addition, while the store is closed, defrosting is performed using a single heater, for example.
Although the defrosting end temperature is set high, the lights in the showcase are turned off, the openings are covered with covers, etc., and the number of products on display is small, so the temperature of the products is kept low, and the defrosting temperature is kept low. The rise in product temperature can be suppressed. Also, by using this defrosting method while the store is closed, the cold appliances can be completely defrosted and ready for when the store opens.

Furthermore, even in the summer, by setting the defrosting end temperature low and performing defrosting, it is possible to prevent the temperature of displayed products from rising due to defrosting.

[Brief explanation of the drawing]

Figure 1 shows the vk frost according to the present invention. tll block diagram, Figure 2 is a cross-sectional view of the cooling showcase showing the flow of cold air during cooling, Figure 3 is a cross-sectional view of the cooling showcase showing the flow of cold air during defrosting during opening, and Figure 4. 1 is a cross-sectional view of the cooling showcase showing the flow of cold air during defrosting when the store is closed, FIG. 5 is a waveform diagram showing the operation of the above-mentioned defrosting device, and FIG. 6 is a block diagram of the defrosting device of another embodiment. 7 is a sectional view of a cooling showcase for explaining the defrosting device shown in FIG. 6, and FIG. 8 is a waveform diagram showing the operation of the conventional defrosting device. l in the figure... Selection circuit 2, 31...
Input terminal 3...Schedule timer 4...Defrost control section 5.6...Defrost cycle timer 7...Temperature sensor 8...・A/D
Converter 9...Cold air outlet 10.11...
... Setting section 12 ... Comparison circuit 13 ... Defrosting end signal sending circuit 14 ...
-Defrosting drive signal output section 15... Inner layer fan motor 16... Outer layer fan motor 17... Solenoid valve 18... Heater 13...・Pipe, 21...Cooling filter 22...Cooler 2t...
・Inner layer fan 24... Refrigerated open showcase 25... Opening 2B...
Air curtain 27... Outer layer fan 28
...Cover 23...Display shelf
30...Sensor 32...AC power supply
33...Lighting switch 34...
Ballast 35...Fluorescent tube 3B...
...Glow starter 37...Relay 37a, 37b...
・Contact 38.40...Temperature sensor 38...Low temperature setting thermostat 41...
・・・High temperature set thermostat 42 ・・・Defrost timer

Claims (2)

[Claims] (1) When defrosting the coolers installed in the cooling showcase, the defrosting stop temperature is changed depending on the changing conditions, such as when the store is open or closed, during the day or at night, or during the summer or winter. A defrosting method for a cooling showcase, characterized in that defrosting is carried out using a cooling showcase. (2) While the store is open or closed, or during the day or night;
Alternatively, a selection circuit is provided that selects one defrosting method from among a plurality of defrosting methods having different defrosting stop temperatures by being supplied with a signal that identifies a change in the situation such as summer or winter; A cooling device equipped with a defrosting drive circuit that outputs a defrosting drive signal for executing defrosting using a designated defrosting method when the defrosting method designation signal output from the selection circuit is supplied. Defrost device in the case.