JPS61180875A - Refrigerator - 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 an improvement in a freezer equipped with a direct cooling type cooler.

(Prior art) In this type of freezer, for example, a direct cooling type cooler divided into two parts is installed in the freezer compartment, and frost is collected by a sublimation phenomenon in the ceiling side direct cooling type cooler equipped with a defrosting heater. There is a device (Japanese Unexamined Patent Publication No. 72777/1983) in which automatic defrosting is carried out periodically using a defrosting heater.

This prior art technology has the advantage of being able to freeze food rapidly using a large direct cooling type cooler, but it has the disadvantage that during defrosting, the heater heats up the inside of the freezer compartment, which tends to cause food to deteriorate.

In addition, a shelf-type direct cooling type cooler was placed inside the intercooled type freezer, and the temperature difference between the intercooled type cooler and the direct type cooler was used to naturally sublimate frost during operation. Things (Unexamined Japanese Patent Publication No. 1983-
No. 158472 and Japanese Patent Application No. 57-43263).

In these prior art techniques, the inside of the freezing chamber is not heated during temperature removal, but there is a problem in that there are restrictions on the size of the direct cooling type cooler.

(Object of the Invention) An object of the present invention is to provide a freezer that can rapidly freeze the inside of the freezer compartment using a large direct cooling type cooler, and does not require heating the inside of the freezer compartment for defrosting.

(Structure of the Invention) The present invention forms the inner wall of a freezer with a direct cooling type cooler, and provides an air outlet and a suction port opening into the freezing chamber near the door of the freezer in a state facing the opening of the freezing chamber, A second cooler and a fan, which has a defrosting heater and operates at a lower temperature than the direct cooling type cooler, are installed in the middle of the duct outside the freezing room that connects the air outlet and the suction port, and the air flow from the air outlet to the suction port is installed. This is a freezer characterized by forming an air curtain by circulating cold air.

(Example) In Fig. 1 showing the case where the present invention is applied to a so-called two-door complete refrigerator-freezer for domestic use, 2 is a freezer section, 4
is the refrigerator part. The freezer compartment 6 and the refrigerator compartment 8 are separated by a partition wall 10 made of urethane foam, and the freezer compartment 6 is kept at a freezing temperature below the freezing point, and the refrigerator compartment 8 is kept at a refrigeration temperature above the freezing point.

The freezer compartment 6 and the refrigerator compartment 8 are each sealed with a door 12.14), and the periphery of the freezer compartment 6 and the refrigerator compartment 8 is surrounded by a heat insulating layer 16 made of urethane foam material.

The inner wall of the freezer compartment 6 includes a clay wall, a lower wall, and both side walls formed by a pipe-on-sheet direct cooling type cooler 20, and a rear wall formed by a plastic molded plate 22 (or aluminum plate may be used). The direct cooling type cooler 20 has a cylindrical shape obtained by bending a vibe-on sheet. There is a slit-shaped air outlet 2 over the entire width on the upper edge of the opening near the jil 12 of the freezer compartment 6.
4 is open, and a similar slit-shaped suction port 26 is opened at a position opposite to the air outlet 24 at the lower edge of the opening.

A duct 28 connecting the suction port 26 and the blowout port 24 is provided along the periphery of the freezing chamber 6, that is, along the lower wall, rear wall, and earthen wall, and the outer surface of the direct cooling type cooler 20 facing the duct 28 A heat insulating layer 30, 32 of urethane foam is pasted on.

Partition wall 10 in the middle of duct 28, that is, near suction port 26
On the top is a fin-shaped cooler 34 formed of fin tubes.
(second cooler) is provided.

The fin type cooler 84 operates at a lower temperature than the direct cooling type cooler 2o. For example, when the direct cooling type cooler 2o operates at -27°C, the fin type cooler 84 operates at -82°C. The moisture in the cold air is caused to form frost on the fin-shaped cooler 84 by natural sublimation. The fin-shaped cooler 84 is equipped with a heater 84a (FIG. 21) that detects the amount of frost and automatically defrosts when a predetermined amount of frost is reached.

A fan 36 is provided in the duct 28 near the downstream side of the fin-shaped cooler 84. It forms an air curtain 81 and also forms a circulation flow 18 within the freezing compartment 6, which serves to forcibly cool the freezing compartment 6.

The partition wall 10K is formed with a refrigerating compartment side suction port 42 and a refrigerating compartment side air outlet 44, and the air outlet 44 is provided with a duct 28.
A damper 46 is provided to adjust the flow rate of cold air inside the refrigerator compartment 8.

A compressor 48 is provided at the bottom of such a refrigerator-freezer, and a condenser 50 is provided at the back.

Further, reference numeral 52 is a tray, and water from the defrosting of the fin type cooler 34 is guided through the tray 52K, and the water is evaporated in the tray 52.

Compressor 48, direct cooling type cooler 20. The connection structure such as the fin-shaped cooler 84 is formed as shown in FIG. That is, the compressor 48 is connected to the condenser 6o, and the condenser 5
0 is connected to the direct cooling type cooler 2o via the first capillary tube 54. A fin type cooler 84 equipped with a heater 84a is connected downstream of the direct cooling type cooler 2o via a second capillary tube 56, and further connected to the compressor 48 via an accumulator 58. 6o
is a bypass circuit), and a solenoid valve 62 is interposed in the middle of the bypass circuit VIIr6o. The solenoid valve 62 and the compressor 48 are controlled according to the temperature conditions of the freezing compartment 6 and the refrigerating compartment 8, and operate both the coolers 20, 84 and the air curtain 88 as shown in Table 1 below. K is set to keep the refrigerator compartment 8 at an appropriate temperature.

Table 1 For example, when the heater 34a is ON, the solenoid valve 62
When the temperature of the freezer compartment 6 rises above the set temperature during defrosting, the compressor 48 is operated to maintain the temperature inside the freezer compartment 6 within the set temperature range. Also, the temperature of refrigerator compartment 8 is appropriate and cold.

The same applies when the temperature of the storage room 6 is inappropriate.

Next, the operation will be explained. Since the freezer compartment 6 is provided with a large direct cooling type cooler 20, the freezer compartment 6 is rapidly cooled within the set temperature range Kt in a short time.

Since the air curtain 88 is formed at the opening of the freezer compartment 6, even when the door 12 is opened, the amount of high temperature and humid outside air flowing into the freezer compartment 6 is significantly reduced as will be described later. Therefore, the amount of frost formed on the direct cooling type cooler 200 is significantly reduced compared to the conventional one, and the cold air passes through the fin type cooler 84, which is equipped with a heater 34a and operates at a lower temperature than the direct cooling type cooler 20. Due to forced circulation, the frost on the direct cooling cooler 20 is removed by natural sublimation during operation and forms frost on the fin cooler 84, and when the amount of frost on the fin cooler 340 increases, the frost on the heater 34a increases. is heated and defrosted. The fin-shaped cooler 34 is placed near the suction port 26 to further promote natural sublimation.

The present inventors conducted an experiment on the effect of the air curtain 38 on preventing intrusion of outside air, and obtained the following results. That is, the wind speed of the air curtain 38 is set to about L5 m/8 at the center, and before the door 12 is opened, the freezer compartment 6 is filled with Cot gas from a Cot cylinder at 101/i for 5 minutes, and then the door 1 is opened.
2 was opened to an angle of 90°, the Cot concentration in the freezer compartment 6 was measured using a Drage μ detection tube, and the amount of C(h gas flowing out was regarded as the amount of outside air entering).

First, when the door 12 is opened for 3 seconds, the results are shown in Table 2 below.

Next, when the door 12 is opened for 10 seconds, the results are shown in Table 8 below.

From these results, it can be seen that the air curtain 38 significantly reduces the amount of outside air entering into the cold storage compartment 6, that is, the amount of Co2 gas flowing out.

(Effects of the Invention) As described above, according to the present invention, the inner wall of the freezer is formed by the direct cooling type cooler 20, the air outlet 24 and the suction port 26 are provided facing each other near the door 12, and the air outlet A fin type cooler 84 (second cooler) having a heater 84a and operating at a lower temperature than the direct cooling type cooler 20 and a fan 86 are provided in the middle of the duct 28 connecting the duct 24 and the suction port 26. So,
The air curtain 88 formed between the blow-off port 24 and the suction port 26 can reduce the amount of high-temperature, humid outside air that enters, thereby reducing the amount of frost formed on the direct cooling type cooler 20. In addition, even a small amount of frost that forms on the direct cooling type cooler 20 is removed by natural sublimation during operation, forms frost on the fin type cooler 84, and is defrosted directly by the heater 34a. There is no need to consider defrosting of the refrigerated cooler 20, the direct cooler 20 can be made larger, and the inside of the freezer compartment 6 can be frozen more rapidly.

(Another Embodiment) (1) The present invention is not limited to the refrigerator-freezer shown in FIG. 1, but can also be applied to a freezer without the refrigerator section 4.

(2) The fin-shaped cooler 34 is made of plastic molded plate 2
It may be located at another location within the duct 28, such as inside the duct 28 on the back side of the 2° (rear wall).

[Brief explanation of drawings]

Claims (1)

[Claims] A type of refrigeration system in which the inner wall of the freezer is formed of a direct cooling type cooler, and an air outlet and suction opening into the freezing chamber are provided near the door of the freezer, facing the opening of the freezing chamber, and the air outlet and suction opening are connected. A second cooler and fan, which has a defrosting heater and operates at a lower temperature than the direct cooling type cooler, are installed in the middle of the outdoor duct to form an air curtain by circulating previously cold air from the outlet to the inlet. A freezer characterized by: