JPH04155171A - Low-temperature cabinet - Google Patents

Abstract

PURPOSE:To achieve humidity control in accordance with the kind of articles in a storage chambers by a method wherein a cold air introducing means, introducing cold air in a cold air circulating space into the storage chamber, is provided while the cold air introducing means is controlled so as to maintain a set humidity based on a humidity in the storage chamber. CONSTITUTION:When a humidity in a storage chamber 10 is increased due to the evaporation of moisture from foods and has arrived at an upper limit humidity, a control device operates a small-size ventilating device 38 based on the output of a humidity sensor S2 and introduced dry and cold air in a cold air circulating space 11 directly into the storage chamber 10 through a through hole 37. When the humidity in the storage chamber 10 is reduced and arrives at a lower limit humidity, the control device stops the small size ventilating device 38 based on the output of the humidity sensor S2 and stops the introduction of the cold air to maintain the humidity in the storage chamber 10 at a set humidity in average. The humidity is risen some times during the stopping of a cooling device 14. However, an electric heater 40 generates heat and, therefore, the operating rate of the cooling device 14 is high and a humidity in the cold air circulating space 11 is reduced by the energizing of dehumidifying effect by a cooler 12 whereby the humidity can be controlled smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a low-temperature refrigerator whose storage compartment is cooled by indirect cooling.

(b) Conventional technology Conventionally, the box body of a refrigerator has a double structure consisting of an insulating outer box and a thermally conductive inner box, and a cooling device is installed between both the inner and outer boxes to protect the inner box and its interior. As for an indirect cooling type low-temperature refrigerator that performs cooling, the applicant has previously filed patent application No. 2-604.
There is No. 02.

The configuration shown therein is located in a cold air circulation space 11 between an insulated outer box 2 and an inner box 3, a cooling device 12 is arranged above the inner box 3, and a first and second blower device 13 and a cooling device 12 are disposed above the inner box 3. The cold air cooled by the cooling 512 by 19 is supplied to the upper space 11A above the top wall 3A of the inner box 3, cooled there, and then flowed to the right side space 11F outside the right side wall 3F.

(c) Problems to be Solved by the Invention According to the configuration, the storage chamber 10 is indirectly cooled from the peripheral wall surface of the inner box 3, so that moisture evaporates from the vegetables, fruits, etc. stored in the storage chamber 10. is retained without escaping to the outside, and therefore the humidity in the storage room lo can be maintained at a high level.

By doing so, it is possible to suppress the quality deterioration due to drying of the above-mentioned living foods and achieve long-term preservation.
Depending on the type of food, excessively high humidity may cause spoilage, which is an undesirable problem.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a low-temperature refrigerator that indirectly cools the storage chamber, which can control the humidity in accordance with the type of goods in the storage chamber by controlling the humidity within the storage chamber. shall be.

(d) Means for Solving the Problems The present invention comprises: an insulating outer box; a thermally conductive inner box disposed at a distance inside the outer box and forming a storage chamber therein;
In a low-temperature refrigerator consisting of a cold air circulation space formed between an outer box and an inner box, a cooler placed in this cold air circulation space, and a blower for forced circulation of the cold air, there is a cold air circulation space inside the storage room. The cold air introduction means is provided to introduce cold air into the storage room, and the cold air introduction means is controlled to maintain the humidity at a set humidity based on the humidity inside the storage room.

Furthermore, a heater is disposed within the cold air circulation space.

(E) Function According to the present invention, the cold air introducing means introduces dry cold air in the cold air circulation space into the storage chamber according to the humidity in the storage chamber to appropriately lower the humidity in the storage chamber and maintain the humidity at the set humidity.

Furthermore, by heating the cold air circulation space with a heater, the cooling operation rate of the cooler can be improved, the cold air in the cold air circulation space can always be maintained in a dry state, and the humidity in the storage room can be smoothly reduced by introducing cold air.

(f) Example Embodiments of the present invention will be described below based on the drawings.

1 is a low-temperature storage such as a prefabricated refrigerator, and an inner box 3 made of a good thermal conductor such as metal is placed inside an insulated outer box 2 with a space therebetween, so that the storage is sealed inside the inner box 3. The chamber 10 and the surroundings of this storage chamber 10, that is, the inner box 3 and the outer box 2
A cold air circulation space 11 is configured in a space surrounded by. The outer box 2 is formed into a box shape by combining heat insulating panels that have convex or recessed parts at the joints with adjacent panels, and the inner box 3 has a top wall 3A, a bottom wall 3B, and front, rear, left, and right side walls 3C13D, It is composed of 3E and 3F.

In addition, on the left side of the front wall of the insulated outer box 2, there is an article inlet/outer lower for loading and unloading stored foods (in this example, agricultural products such as vegetables and fruits), and an article inlet/outer lower that can be opened and closed at will, and the storage room IO is closed. A heat insulating door 8 is provided.

On the lower surface of the right end of the top wall 2A of the outer box 2, a cooling device 14 for the inside of the refrigerator is attached, located in the cold air circulation space ll. The cooling device 14 consists of a cooler 12 typified by an evaporator forming part of a refrigeration cycle, a blower fan, and a blower fan motor, and is intermittently controlled by a temperature sensor S1 that detects the temperature inside the storage room IO. 1st driven
It has a built-in air blower 13.

Incidentally, the intermittent operation means an operation control in which the operation is stopped when the temperature detected by the temperature sensor S1 becomes below the lower limit temperature, and enters the operating state when the temperature becomes above the upper limit temperature.

Reference numeral 16 denotes a partition plate that cooperates with the cooling device 14 to partition the upper space 11A into a high-pressure area 20 and a low-pressure area 21, and is located approximately in the center of the upper space 11A on the downstream side of the article inlet/output lower in the cold air circulation direction. Placed. Two ventilation ports 18 are formed in this partition plate 16, and second ventilation devices 19 and 19 that are always operated are arranged so as to be located closer to the insulation door 8 than the first ventilation device 13. It is set up.

The cold air circulation space 11 includes an upper space 11A as a space above the top wall 3A, a bottom space 11B as a space below the bottom wall 3B, a front space 11C as a space outside the front wall 3C, and a rear wall. A rear space 11D as a space on the outside of the 3D, and a left side space 1 as a space on the outside of the left wall 3E.
1E, and the right side space 11 as the space on the outside of the right wall 3F.
In this example, the cooling device 14 is arranged in the upper space 11A.

On the other hand, in order to attach the inner box 3 to the outer box 2 at a predetermined interval, a plurality of metal supports 30 are used. The plurality of pillars 30 connect a space 11C formed by the inner box front wall 3C and the outer box 2 to a front high pressure region 31 and a low pressure region 21 that communicate with the high pressure region 20 around the left and right sides of the heat insulating door 8. The space 11D formed by the first strut 33 that vertically partitions the front low-pressure region 32, the inner box rear wall 3D, and the outer box 2, and the rear high-pressure region 34 and the low-pressure region that communicate with the high-pressure region 20. 21 and a rear low-pressure region 35 that communicates with the rear low-pressure region 35.

Further, a through hole 37 is formed in the left side wall 3E of the inner box 3 located in the low pressure area 21 of the cold air circulation space 11, and a small blower device 38 consisting of a fan and a fan motor as a means for introducing cold air is arranged therein. , Furthermore, in parallel with the same wall 3E, a wall of 50 m in diameter is installed to the extent that it does not affect the humidity in the storage room 10.
A small hole 39 with a diameter of about m) is bored. In addition, storage room 10
A humidity sensor S2 for detecting the humidity inside the storage chamber 10 is provided inside.

Furthermore, in the upper space 11A of the low pressure area 2111!1, there is an electric heater 4 for heating the cold air in the cold air circulation space 11.
0 is placed.

In the above configuration, cooling of the low-temperature refrigerator 1 will be explained.

First, food, such as agricultural products such as vegetables and fruits, is stored in the uncooled storage chamber 10, the set temperature is set to the refrigeration temperature range (for example, +2° C.), and the cooling device 14 is operated. Since the temperature inside is higher than the set temperature,
Based on the output of the temperature sensor S1, the cooling device 14 is operated by a control device (not shown), and the air in the high pressure area 20 of the upper space 11A is sucked by the first blower device 13, flows into the cooler 12, and is cooled. After that, right space 11
F is blown out.

On the other hand, the air in the cold air circulation space 11 is transferred to the second air blower 19.
．． 19 forcibly circulates around the outside of the inner box 3, and from the high pressure area 20 of the upper space 11A to the front and rear right spaces 11C, I
Since the cool air passing through ID and IIF is guided to the bottom space 11F3, passes through the left side space 11E and the low pressure area 35, and returns to the low pressure area 21 of the upper space 11A, the cooler 12 cools the cool air flowing in the upper space 11A. The cool air blown out from the cooler 12 also circulates within the space 11 along with this flow.

This cold air circulation cools the upper, front, rear, left, and right walls 3A to 3F, and the inside of the storage chamber 10 is indirectly cooled by radiant heat from each wall surface. Further, since the inside of the sealed cold air circulation space 11 is divided into a high pressure area 20 and a low pressure area 21 by the partition plate 16, the second air blower 19.19 forcibly pressurizes the circulating cold air in the space. By creating a difference, the cold air in this space is diffused over a wide range, and the cold air is evenly circulated in the cold air circulation space 11, efficiently cooling the entire inner box 3, and the storage chamber 10 is spread around the bottom. Cooling can be done from both the left and right sides.

Next, FIG. 4 shows the relationship between the operation/stop of the small air blower 38 and the humidity inside the storage chamber 10. Set humidity H
8 is, for example, 80%, H)I indicates the upper limit humidity of 85%, and HL indicates the lower limit humidity 75%. As can be seen from the figure, the cooling device 1i14 is operated intermittently based on the temperature in the storage room as described above, the blower device 19 is operated continuously, and the electric heater 40 is continuously energized to generate heat. It is assumed that the set humidity H8 is set at an optimal storage humidity depending on the type of food to be stored.

When the humidity in the storage chamber 10 rises due to the evaporation of moisture from the food and reaches the upper limit humidity H[(, the control device (not shown) operates the small blower device 38 based on the output of the humidity sensor S2, The dry cold air in the cold air circulation space 11 is directly introduced into the storage chamber 10 through the small hole 37. At this time, the presence of the small hole 39 allows the cold air to be smoothly introduced into the closed space.

The humidity in the storage room 10 decreases as the dry cold air is introduced, and when it reaches the lower limit humidity HL, the control device stops the small air blower 38 and stops introducing the cold air, based on the output of the humidity sensor S2. By these control operations, storage chamber 1
The humidity within 0 is averaged and maintained at the set temperature H5.

At this time, while the cooling device 14 is stopped, the humidity in the cold air circulation space 11 is reduced to 80% because the dehumidifying effect of the cooler 12 is lost.
% to 100%. Even if the small blower device 38 is operated in such a situation, a decrease in humidity within the storage room 10 cannot be expected.

However, in the present invention, since the electric heater 40 generates heat, the operating rate of the cooling device 14 becomes high.

Therefore, the humidity of the cold air in the cold air circulation space 11 is reduced by the cooler 12.
It decreases due to the activation of the dehumidifying effect of
70%, so when the small air blower 38 is operated, the humidity in the storage room 10 is reliably reduced, and humidity control can be performed smoothly.

In the embodiment, the cold air introducing means is constituted by the small blower device 38, but the present invention is not limited to this, and the area of the through hole 37 may be enlarged and the cold air introduction means may be constituted by a combination of this and an opening/closing plate. In that case, the opening/closing plate may be opened/closed based on the humidity sensor S2.

(g) Effects of the Invention As detailed above, according to the present invention, the dry cold air in the cold air circulation space is introduced into the storage room by the cold air introducing means according to the humidity in the storage room, and the humidity in the storage room is appropriately reduced. This allows the humidity in the storage room to be maintained at a set humidity depending on the type of article, and the storage performance of the article can be further improved.

Furthermore, by heating the cold air circulation space with a heater, the cooling operation rate of the cooler can be improved, the cold air in the cold air circulation space can always be kept in a dry state, and the humidity inside the storage room can be reliably reduced by introducing cold air. , the control performance of the humidity inside the storage room can be improved.

[Brief explanation of drawings]

FIG. 1 is a plan sectional view taken in the upper space of the low-temperature refrigerator of the present invention, FIG. 2 is a vertical sectional view thereof, and FIG. 3 is A-A in FIG.
The line cross-sectional view, FIG. 4, is a diagram showing a small air blower and the like and changes in humidity in the storage room. 1...Low temperature storage, 2...Insulated outer box, 3...Inner box, 1
0...Storage room, 11...Cold air circulation space, 12...Cooler, 13...First blower, 14...Cooling device, 19.19...Second blower, 37...Through hole,
38...Small air blower, 39...Small hole, air heater at 40, S2...Humidity sensor. s2 figure I/13 figure EI

Claims (1)

[Scope of Claims] 1) A heat-insulating outer box, a thermally conductive inner box disposed at a distance inside the outer box and forming a storage chamber therein, and the outer box and the inner box. In a low-temperature refrigerator comprising a cold air circulation space formed between the cold air circulation space, a cooler disposed in the cold air circulation space, and a blower device for forced circulation of the cold air, the cold air in the cold air circulation space is placed in the storage room. 1. A low-temperature refrigerator, comprising: a cold air introduction means for introducing cold air, and the cold air introduction means is controlled to maintain a set humidity inside the storage room based on the humidity inside the storage room. 2) The low temperature refrigerator according to claim 1, further comprising a heater disposed within the cold air circulation space.