JPH0634243A - Cooling device - Google Patents

Abstract

PURPOSE:To carry out a positive defrosting operation by a method wherein first heat exchangers, a defrosting heater and second heat exchangers are arranged along a direction across an air flow and the number of rows of the first heat exchangers is made more than that of the second heat exchangers. CONSTITUTION:A cooling device is constructed such that first heat exchangers 11, a heater 8 acting as a defrosting heater and second heat exchangers 12 are arranged in sequence along a discharging flow direction within a spacing between a ceiling plate 1 and a drain pan 2 having a bell mouth part 4 where a blower 5 is installed. The number of rows of the first heat exchangers 11 are three rows, for example, and are made more than that of the second heat exchanger 12 arranged in only one row. An inter-fin spacing of the first heat exchangers 11 is made smaller than an inter-fin spacing of the second heat exchangers 12. With such an arrangement, an amount of frosting of the first heat exchangers 11 is increased and a defrosting operation is stopped with a defrosting completion sensor 13 arranged at the first heat exchanger 11, thereby even if an eccentric frosting occurs in the second heat exchangers 12, it is possible to perform a positive defrosting operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device, and more particularly to the structure of a heat exchanger having a heating body for defrosting.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing a schematic configuration of a conventional cooling device disclosed in, for example, Japanese Patent Laid-Open No. 3-67977. In the figure, 1 is a ceiling plate, 2 is a drain pan rotatably attached to the ceiling plate 1 via a hinge 3,
A bell mouth portion 4 is formed on the air inflow side. Reference numeral 5 denotes a blower provided in the bell mouth portion 4, and reference numerals 6 and 7 denote first and first fans arranged in a direction traversing a flow of air discharged from an arrow A direction to an arrow B direction with a predetermined gap. In the second heat exchanger, as shown in FIG. 4, the first heat exchanger 6 has a cooling pipe 6c whose both ends are supported by both side plates 6a and 6b and through which a refrigerant flows, and an air flowing through the cooling pipe 6c. A plurality of fins 6d fixed in parallel with the flow, and the second heat exchanger 7 is supported at both ends by both side plates 7a and 7b. And a plurality of fins 7d that are fixed in parallel with the above flow. The mounting distance a of the fins 7d is larger than the mounting distance b of the fins 6d.

Reference numeral 8 indicates both side plates 6a, 7 of both heat exchangers 6, 7.
It is a defrosting heater having both ends supported by both side plates 8a, 8b which are provided so as to be connected between a and 6b, 7b and form a gap 9 between the heat exchangers 6, 7. Defrosting termination detector 10 is attached to the cooling pipe 7c.

Next, the operation of the conventional cooling device constructed as above will be described. First, during the cooling operation, the hot and humid air introduced from the direction of arrow A in the figure by the blower 5 is
The second heat exchanger 7 is cooled and a large amount of frost is formed on the second heat exchanger 7. The air dehumidified here is further cooled by the first heat exchanger 6 and discharged in the direction of arrow B. At this time, a small amount of frost also forms on the first heat exchanger 6. When a predetermined amount of frost is reached while continuing the cooling operation in this way, a defrosting device (not shown) operates and the heater 8 is energized. The frost generated in the first heat exchanger 6 and the second heat exchanger 7 by the heating of the heater 8 is melted and drops on the drain pan 2. When the frost melts, the temperature of the heat exchanger 7 rises and the defrosting termination detector 10 terminates the defrosting operation.
In order to increase the heat exchange capacity, the refrigerant is made to flow from the first row to the fourth row in the air inflow direction and the counter flow.

[0005]

Since the conventional cooling device is constructed as described above, there is no problem in defrosting under high temperature and high humidity conditions because the frost formation on the first heat exchanger increases. However, when the sucked air has a low humidity and is operated for a long time, the amount of frost formed on the second heat exchanger 7 increases, resulting in uneven frost formation. When the defrosting operation is started in this state, the temperature rising speed of the second heat exchanger 7 to which the defrosting end detector 10 is attached increases, and frost remains on the first heat exchanger 6. Nevertheless, the defrosting termination detector 10 was activated and there was a problem such as residual frost.

The present invention has been made in order to solve the above-mentioned problems, and a cooling device capable of performing a reliable defrosting operation even when partial frost is formed on the first and second heat exchangers. The purpose is to get.

[0007]

In the cooling device according to the present invention, the first heat exchanger, the defrosting heating body, and the second heat exchanger are arranged along the direction transverse to the air flow. In the cooling device, the number of rows of the first heat exchanger is made smaller than the number of rows of the second heat exchanger, and the defrosting termination detector is attached to the second heat exchanger. is there.

[0008]

According to the cooling device configured as described above, the number of rows of the first heat exchanger is greater than that of the second heat exchanger, and the defrosting completion detector is the first heat exchanger. Since the first heat exchanger has a large amount of frost even under various frost conditions due to the arrangement, the defrosting termination detector is installed in the first heat exchanger. A reliable defrosting operation can be performed.

[0009]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. 1 and 2, the ceiling plate 1, the drain pan 2, the hinge 3, the bell mouth portion 4, the blower 5, the defrosting heater 8 and the gap 9 are the same as those in the conventional device shown in FIG. 1 and 2
11 is a cooling pipe 11C from the first row to the third row
Is a first heat exchanger composed of both tube plates 11a and 11b and fins 11d. Reference numeral 12 is a second heat exchanger composed of the cooling 12c in the fourth row, both tube plates 12a and 12b, and the fins 12d. Reference numeral 13 is a defrosting completion detector attached to the first heat exchanger.

Next, the operation of the cooling device of this embodiment having the above construction will be described. First, the air introduced from the bell mouth portion 4 in the direction of arrow A by the blower 5 is cooled by the second heat exchanger 12 and further cooled by the first heat exchanger 11. Frost forms on the first and second heat exchangers 11 and 12,
The first heat exchanger 11 having a large number of rows of cooling pipes is more frosted than the second heat exchanger 12. In this way, when the predetermined amount of frost is reached while continuing the cooling operation, the defroster (not shown) operates in the same manner as in the conventional case, and the heater 8 is energized. By energizing the heater 8, the first and second heat exchangers 1
The frost adhering to 1 and 12 is melted and drops onto the drain pan 2.

At this time, the first heat exchanger 1 having a large amount of frost formation
The temperature rising speed of 1 is slower than that of the second heat exchanger 12. However, the defrosting end detector 13 is the first heat exchanger 1
Since the frost of the second heat exchanger 12 is completely melted, the temperature of the first heat exchanger 11 reaches a predetermined value and the defrosting end detector 13 operates. In this way, the defrosting operation ends. Therefore, there is an excellent effect that the defrosting operation can be surely performed even if the second heat exchanger 12 is partially frosted. In the above embodiment, the first and second heat exchangers 11 and 12 have three rows and one row, respectively. However, the number of rows of the first heat exchanger 11 is not limited to this. The defrosting termination detector 13 may be installed on the first heat exchanger 11 side.

[0012]

As described above, according to the present invention, the number of rows of the first heat exchanger on the air blowing side is larger than that of the second heat exchanger on the suction side, and the defrosting end detector is used. Since it is arranged in the first heat exchanger, there is an excellent effect that the defrosting operation can be surely performed even when frost is eccentrically deposited on the second heat exchanger.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of a cooling device according to an embodiment of the present invention.

FIG. 2 is a detailed view showing a main part of the cooling device.

FIG. 3 is a cross-sectional view showing a schematic configuration of a conventional cooling device.

FIG. 4 is a detailed view showing a main part of a conventional cooling device.

[Explanation of symbols]

 11 1st heat exchanger 12 2nd heat exchanger 13 Defrosting termination detector

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsunori Horiuchi 6-566 Tehira, Wakayama City Mitsubishi Electric Engineering Co., Ltd. Itami Works Wakayama Branch

Claims (1)

[Claims] 1. A cooling device in which a first heat exchanger, a defrosting heating body, and a second heat exchanger are arranged along a direction traversing an air flow, wherein A cooling device characterized in that the number of rows is smaller than the number of rows of the second heat exchanger, and a defrosting termination detector is attached to the second heat exchanger.