JPS58148379A - Penumatic defrosting operation method for open showcase - 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 This invention relates to an improvement in the pneumatic unregistering operation method of a multi-layer oven showcase for freezing and refrigerating specifications. The configuration and cold storage operation will be explained. In the figure, 1 is an outer box of the case body, 2 is an inner box, and 3 is a product display shelf. There is a gap l1 between the outer box 1 and the inner box 2 in the case body.
An inner duct 5 and an outer duct 6 are formed in two layers, an inner duct 5 and an outer duct 6, which are partitioned by a duct 14 and serve as a circulation air passage.In each duct, an inner 7 and an outer fan 8 are respectively installed, and an evaporator of the refrigerator is installed in the inner duct. A cooler 9 is installed.

In addition, the ducts 5 and 6 of each layer open upward and downward toward the front opening 10 of the case body, and the air curtain Akita 01
1, 12 and suction port 13-. 14 is formed. Here, the air curtain outlet 11 of the inner duct 5 is lined up on the inside, and the air curtain outlet 12 of the outer duct 6 is lined up and open on the outside.

In the above configuration, each duct 5, 6 is operated by operating the cooler 9 and each fan 7.8 during cold storage operation.
Air is blown inside as shown by the arrow, and air curtains B and B are blown into the front opening 1o of the nurse body, which are divided into two layers, inside and outside, forming a laminar flow from the upper air outlet to the lower suction port. Of these, inner air curtain A is a cold air curtain that is cooled by heat exchange with cooling-9,
An outer air curtain B extending outward protects the inner air curtain A, and these two curtains cut off the outside air to prevent heat from entering the warehouse and keep the displayed products cool. Note that the wind speeds of air curtains A and B are determined so as to obtain optimal air curtain characteristics.

By the way, as is well known, as time elapses during the above-mentioned cold storage operation, frost builds up on the surface of the cooler 9 and gradually accumulates, causing a phenomenon of frost formation.

When the cooler becomes covered with frost, it not only reduces the heat exchange efficiency, but also narrows the ventilation passages in the duct, making it impossible to secure the required circulating air volume, resulting in deterioration of air curtain characteristics and reduction in cold storage performance. This will eventually lead to an increase in the temperature of the products in the warehouse. For this reason, generally, the cooler 9 is temporarily stopped after a certain period of time has elapsed during the cold storage operation, and the frost adhering to the cooler 9 is melted and removed.

As the above-mentioned defrosting methods, heater methods, hot gas methods, and the like are well known, but these methods consume a large amount of power even during defrosting. Therefore, for the purpose of saving power consumption, the defrosting heat source is the air inside the case with high enthalpy, and the outside air around the case is actively cooled during defrosting. i
A so-called pneumatic defrosting method has been proposed, and has been put into practical use in some cases, in which the outside air is guided to the inner duct 5 in which the cooling air 9 is installed, and defrosting is performed by giving the heat retained in the outside air to the cooling air 9.

Next, a conventional defrosting operation method for improving the pneumatic defrosting method described above will be explained with reference to FIG.

That is, when the cooling operation is switched to defrosting, the cooler 9 is stopped and the outer fan 8, which uses a reversible seven unmotor, is switched to reverse operation. In addition, inner 7
Ann 7 continues to operate as in the cold storage operation. Therefore, the ventilation state of each duct is as shown by the dotted line arrow in the figure, in which the outside air in the case ms is sucked in from the air curtain outlet 12 of the outer duct 6, is discharged from the air curtain intake port 14 via the outer duct 6, and then changes direction. The defrosting exhaust gas is sucked into the inner duct 5 through the air curtain suction port 13, and is discharged from the air curtain outlet 11 as shown by the chain arrow, after exchanging heat with the cooler 9, and is then introduced into the inner duct 5 through the front opening of the case. While flowing down the part 1o to form an air curtain, a part of the air mixes with the outside air and returns to the inner duct 5, and the rest is dissipated outside the nurse. In this way, outside air is continuously introduced into the inner duct 5, and pneumatic defrosting is performed in the process of flowing through the cooler 9. Furthermore, that driving chart is the 5th v! It's like J.

However, in the conventional operating method described above, before the outside air (5) is introduced into the inner duct 5, the outer duct 6
The heat loss in the duct route is large and the defrosting efficiency is low. Further, a part of the defrosting exhaust air is sucked into the inner duct 5 again, so that the defrosting air sent to the cooler 9 is combined with the defrosting exhaust air whose temperature has decreased and the case PR11! The enthalpy of the defrosting air is lower than that of the air surrounding the nurse, which results in a longer time for defrosting in addition to the heat loss.

Moreover, if the defrosting time takes a long time, the cooler 9 is stopped during this time, so cold storage is not performed, and the influence on the rise in the temperature of the products in the refrigerator becomes greater.

This invention solves the drawbacks of the conventional defrosting operation method described above, suppresses the rise in product temperature, prevents product damage and frost formation due to heat shock, and makes it possible to complete 1 bll in a short time. The purpose is to provide a pneumatic defrosting operation method with high defrosting performance.

According to the present invention, this purpose is to stop the operation of the cooler during defrosting, and to switch the outer fan from normal rotation to reverse rotation throughout the entire defrosting period (6).
This is achieved by operating the inner fan by switching from forward rotation to reverse rotation except for predetermined times at the beginning and end of the defrosting period.

The present invention will be described in detail below based on illustrated embodiments.

Figures 3 to 5 Fj! J indicates the ventilation conditions at the initial stage of defrosting and the final stage before defrosting, and an operation chart according to the embodiment of the present invention. Ori,
When the timer control switches the operation mode from cold storage operation to defrost operation every 4 hours, for example, the cooling unit 9, that is, the refrigerator, is stopped, and at the same time, the fans 7.8 change from normal rotation to reverse rotation according to the operation chart in Figure 6. Operation is controlled.

First, the basic defrosting operation, which is the main part of the defrosting method according to the present invention, will be described with reference to FIG. In the state shown in FIG. 4, both the 7-angs 7 and 8 are operated by switching from normal rotation to reverse rotation, contrary to the cold storage operation.

Therefore, as shown by the dotted line arrow, the air curtain opening 11.
Outside air is drawn directly into the inner duct 5 and the outer duct 6 through the air curtain 12, and after flowing through each duct, is blown upward through the air curtain suction ports 13 and 14. Moreover, this emitted air goes in a direction that opposes gravity, and mixes and disturbs each other.
．． 12 and is emitted from the front to the outside of the case.

Therefore, the air curtain openings 11 and 12 are open.

Therefore, only the outside air with high enthalpy is continuously drawn in, and the amount of defrosting heat given to the cooler 9 is correspondingly large.
ViAH will proceed.

On the other hand, if defrosting is performed using the above defrosting operation method throughout the entire defrosting period, the time required to complete defrosting can be shortened, but on the other hand, during this period, the defrosting exhaust air is Because an air curtain is not formed and a relatively large amount of outside air enters the refrigerator, the temperature inside the refrigerator increases, especially when the product is sufficiently cold after switching from cold preservation to defrosting. Then, when the outside air comes into contact with the product, the *m of the product
Frost and dew buildup are more likely to occur on the noodles, and the quality of the noodles deteriorates due to heat shock, causing a decline in product value.

Therefore, as shown in the operation chart of FIG. 6, the present invention provides a predetermined time difference Δt1 and
T! is set, and during this period only the inner 7 is set as shown in Figure 3.
While Anne 7 is running in the normal direction, only the outer fan 8 is operated in the reverse direction.
Similar to the method shown in Fig. 2, defrosting is performed while forming a defrosting exhaust air curtain in the front opening 10 of the case body, and the remaining time excluding this period is the defrosting process shown in Fig. 4 described above. By carrying out the defrosting process, the defrosting process was skillfully balanced throughout the entire defrosting period.

In this way, by dividing defrosting into six stages: front, middle, and rear, and switching between the defrosting methods shown in Figures 3 and 4 midway through,
First, there is no sudden intrusion of outside air into the refrigerator in the early stages of unregistering, immediately after switching from cold preservation operation to defrosting, so it is less likely that heat shock or frost will occur on the products even though the products are sufficiently cold. . After that, according to the method shown in Figure 4,
Defrosting progress is accelerated by efficiently introducing outside air into the cooling l1I9.

Furthermore, by switching again to the method shown in Fig. 6 (9) at the end of the period before the end of defrosting, defrosting heat is applied to the cooling 119, and an inner air curtain is blown out by the defrosting exhaust gas whose temperature has decreased, and the next In preparation for the transition to cold preservation operation, it is possible to prevent a large rise in the temperature inside the refrigerator at the end of defrosting, and ideally the removal operation will proceed throughout the entire WklI period. By using a variable motor for the 7-arm motor and increasing the speed of the 7-arm motor during reverse rotation, it is possible to increase the amount of outside air intake and complete defrosting in a shorter time. According to this invention, it is possible to complete defrosting more efficiently and in a shorter time than conventional defrosting operation methods while preventing N buildup and heat shock to products in the refrigerator. Practical and effective pneumatic defrosting operation method that effectively prevents product temperature rise and damage! I can provide.

[Brief explanation of the drawing]

Figure 1 is a diagram of the cold storage operation state of the open case, Figure 2
The figure is a diagram of the defrosting operation state according to the conventional defrosting operation method, and FIGS. 3 and 4 are S diagrams of the defrosting operation state showing the ventilation state of defrosting air at different stages according to the embodiment of the present invention (10), respectively. FIGS. 5 and 6 are expulsion operation charts of the conventional vehicle and the present invention. 1: Case body outer box, 2: Inner box, 5: Inner tact, 6
: Outer duct, 7: Inner fan, 8: Outer fan, 9: Cooler, 1o: Front opening. l 11) Figure 71 Figure 3 Figure 72 Figure 4

Claims (1)

[Claims] 1) An inner duct and an outer duct surrounding the outer periphery of the inch duct are provided between the outer box and the inner box of the front aperture type case body, and the inner duct is provided with a cooler and an inner duct. The open show system has an outer fan installed in the outer duct, and operates the cooler and each fan during cold storage operation to blow out multiple layers of cold air curtains inside and outside the front opening of the case body through each duct. In this case, during defrosting, the operation of the cooler is stopped, and the outer 7 ann is switched from normal rotation to reverse rotation throughout the entire defrosting period, and the inner 7 ann is operated during the initial and final stages of the defrosting period. A single-bun showcase characterized in that the operation is switched from normal rotation to reverse rotation except for a predetermined period of time, and outside air is forcibly introduced into the inner duct to defrost the cooler using the heat held by the outside air. pneumatic defrosting operation method. 2. The pneumatic defrosting method for an open showcase in which the inner fan and the outer fan are operated at increased speeds when reversed.