JP2001012844A - Cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent refreezing of a dew receiving plate caused by insufficient heating by providing the dew receiving plate with a heating element having a large calorific power in the vicinity of a drainage hole, while avoiding the influence of heat generated by the heating element upon refrigerating performance. SOLUTION: A cooling unit 2 is installed on the lower surface of a top wall constituting the ceiling of a refrigerator. The cooling unit 2 consists of an evaporator 7 fixed to the top plate of a casing with screws, an electric heater provided in the evaporator 7, a steel dew receiving plate 9 attached to the lower end portion of the casing, a heating element H provided in the dew receiving plate 9 and the like. The casing has an inlet at the side of the evaporator 7 and an outlet at the side of a cooling fan. In addition, the dew receiving plate 9 under the outlet includes a drainage hole 15, to which a drainage hose is connected and led outside the refrigerator. The cooling unit 2 is attached to the ceiling surface by way of a hanger fixed to the four corners of the casing with screws.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device having an evaporator and a dew receiving plate in a heat insulating box.

[0002]

2. Description of the Related Art Conventionally, a cooling device of this type is provided with an evaporator, a blower, An evaporator defrost heater for melting the frost attached to the evaporator is provided, and an evaporator dew receiving plate is provided below the evaporator, and a blower dew receiving plate is provided below the blower. Is provided with a collecting dew receiving plate. When the frost adhering to the evaporator is melted by the evaporator defrost heater, it becomes defrosted water, is received by the evaporator dew receiving plate and the blower dew receiving plate, and is collected by the collective dew receiving plate. . The collecting dew receiving plate has a heater, and the defrost water is heated by the heater and drained to the outside through a drain hose.

[0003]

However, in the above conventional method, since the air temperature in the storage chamber is low, the collecting dew receiving plate is deprived of heat, and the defrost water is re-frozen on the collecting dew receiving plate.
Ice may grow with the passage of time, and in severe cases, the upper evaporator may be clogged with frost, preventing the flow of cool air and causing a decrease in cooling performance. Also,
The growth of the re-frozen ice sometimes deformed or damaged the dew receiving plate. Therefore, it is necessary to raise the temperature of the collecting dew receiving plate to prevent re-freezing. Conventionally, a heater provided on the collecting dew receiving plate is always energized to reduce the temperature of the collecting dew receiving plate to water. The method of securing the temperature above the freezing point was adopted. However, in this method, the heat of the heater becomes a heat load during the cooling operation, which may affect the cooling performance. Further, since the power is always supplied, there is a problem that the power consumption is large. As one method for solving the above-mentioned problem, there is a method of energizing the heater only at the time of defrosting. Temperature was insufficiently heated and sometimes re-frozen. In addition, there is a disadvantage that a heater having a large calorific value is required, resulting in an increase in cost and a rise in temperature in the storage chamber. Furthermore, since there is a large amount of defrost water and ice blocks near the drain, despite the fact that the heater needs more heat than other parts,
Since a heater having a substantially uniform calorific value was used, the ice block could not be completely melted and sometimes re-frozen.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and a cooling device capable of preventing re-freezing due to insufficient heating of a dew receiving plate while avoiding the influence of heat generated by a heater on cooling performance. The purpose is to provide.

[0005]

According to a first aspect of the present invention, there is provided a cooling apparatus comprising: an evaporator provided in a heat insulating box; and a dew receiving plate having a drain port and provided below the evaporator. A heating element having a large heat value in a portion close to the drain port is provided on the dew receiving plate.

According to the first aspect of the present invention, even if a large amount of ice blocks is present in the portion near the drain port of the dew receiving plate, the ice blocks are completely melted and drained, and do not freeze again. Therefore, the cooling performance does not deteriorate due to the frost blockage of the evaporator above the dew receiving plate, and the dew receiving plate is not deformed or damaged due to the growth of re-frozen ice.

According to a second aspect of the present invention, there is provided a cooling apparatus comprising: an evaporator provided in a heat insulating box; and a dew receiving plate having a drain port and provided below the evaporator.
The dew receiving plate is provided with a first heating element that is energized at the time of defrosting and a second heating element that is constantly energized at the time of defrosting.
Is disposed closer to the drain port than the first heating element.

According to the second aspect of the present invention, there is no heat radiation from the first heating element during the cooling operation, and only the heat of the second heating element becomes the heat load during the cooling operation. Since the amount of heat generated from the heat generating element during such a cooling operation is small, it does not affect the cooling performance. In addition, since the second heating element is always energized not only at the time of defrosting but also at the time of the cooling operation, since the dew receiving plate is already warmed at the start of defrosting, the defrosted water in the portion near the drain port is re-used. There is no freezing, and drainage can be reliably performed.

According to a third aspect of the present invention, in the cooling device according to the second aspect, the first heating element is provided so as to generate a large amount of heat in a portion of the dew receiving plate near the drain port.

According to the third aspect of the present invention, the portion of the dew receiving plate close to the drain port where the defrost water is liable to be re-frozen is moved to the second port.
In addition to the heating by the heating element, the first heating element is heated by the heat generated by the portion of the first heating element having a large calorific value, so that the ice blocks near the drainage port must be thawed and drained from the drainage port. Can be.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a cooling unit 2 of a cooling storage 1 as an embodiment of a cooling device to which the present invention is applied. The cooling storage 1 is, for example, a prefabricated refrigerator / refrigerator, and is configured by assembling a plurality of prefabricated heat insulating panels.
The cooling unit 2 is attached to the lower surface of the ceiling wall 1A which becomes the ceiling surface 3A. The cooling unit 2 is provided with a casing 4 made of a steel plate and housed in the casing 4.
An evaporator 7 screwed to a top plate 6, an electric heater 5 for defrosting provided on the evaporator 7, a cooling fan 8 for the evaporator, and a steel plate attached to the lower end of the casing 4. And a heating element H provided on the dew receiving plate 9. The casing 4 has an inlet 11 formed on the evaporator 7 side and an outlet 12 formed on the cooling fan 8 side.

Further, a fan guard 13 is attached to the outside of the outlet 12, and a drain port 15 is formed in the exposure receiving plate 9 on the lower surface, and a drain hose 14 is connected and connected to be drawn out of the refrigerator. ing. The cooling unit 2 includes hangers 16, 1 screwed to four corners of the casing 4.
6 and 17, 17 attached to the ceiling surface 3A.

Next, a cooling unit 2 according to a first embodiment of the present invention will be described with reference to FIG. FIG. 2 shows the cooling unit 2
FIG. On a dew receiving plate 9 provided below the evaporator 7, a heating element H having a plurality of bent portions 10 using an electric heater coated with metal is provided. Are fixed to the dew receiving plate 9 by a predetermined curvature so as to be detachably fitted to the outer surface of the heating element H and fixed to the dew receiving plate 9 by spot welding. The heating element H is fixed to the upper surface of the dew receiving plate 9 with the fixing members 19, 19. The heating element H has a shape in which the bent portion 10 is increased in the portion 20 near the drain port 15 of the dew receiving plate 9, and the density of the heating element per unit area is made higher than other portions. The amount of heat per unit area to be heated is increased at a portion 20 close to the drain port 15. In addition, the upper surface of the dew receiving plate 9 has a slight inclination in both the longitudinal direction and the short direction toward the drain port 15 so that the defrost water can easily flow. Has become.

With the above arrangement, when the cooling operation is started, a compressor (not shown) is driven, a refrigerant is supplied from a condensing unit (not shown) to the evaporator 7, and the evaporator 7 exerts a cooling action by the cooling fan 8. . By the operation of the cooling fan 8, cool air in the interior 3 is sucked from the suction port 11, exchanges heat with the evaporator 7 in the casing 4, and is blown out from the outlet 12 into the interior 3.

If the cooling operation is continued, frost adheres to the evaporator 7, so that it is necessary to periodically perform a defrosting operation. Energize and generate heat to the provided defrosting electric heater 5,
The frost attached to the evaporator 7 is melted, and defrost water and ice blocks are dropped on the dew receiving plate 9. At this time, the defrost water that has fallen on the dew receiving plate 9 freezes again when the dew receiving plate 9 is cold.
Drainage is not performed smoothly. Also, the growth of ice blocks re-frozen between the dew receiving plate 9 and the lower part of the casing 4 may deform or damage the dew receiving plate 9. In such a case,
The cooling unit 2 is attached to the lower surface of the ceiling wall 1A, which is the ceiling surface 3A of the inside 3 of the cooling storage room 1, and the dew receiving plate 9 constitutes a part of the appearance of the cooling unit 2; Breakage significantly reduces commercial value.

In this embodiment, since the heating element H has a shape having a large number of bent portions 10 at a portion 20 near the drain port 15 of the dew receiving plate 9, the density of the heating element per unit area is higher than other portions. Therefore, the portion 20 of the dew receiving plate 9 near the drain port 15 is further heated, so that even if there is a large amount of ice blocks, it is easy to be melted and does not freeze again. Therefore, the drainage is performed smoothly, and the dew receiving plate 9 is not deformed or damaged by the growth of the re-frozen ice. The defrost water is discharged to the outside from the drain port 15 of the dew receiving plate 9 via a drain hose 14 having a resin heating element 18 wound around the outer periphery thereof in order to prevent freezing during drainage. Is done.

Next, a cooling unit 21 according to a second embodiment of the present invention will be described with reference to FIG. Hereinafter, components denoted by the same reference numerals as those in the above-described embodiment have the same or similar functions. In this embodiment, the dew receiving plate 9 is provided with a first heating element H1 and a second heating element H2, and the first heating element H1 is energized only during defrosting, and the second heating element H1 is supplied with electricity. H2 is always energized. Further, the first heating element H1 is provided farther from the drain port 15 in the dew receiving plate 9 than the second heating element H2, and the second heating element H2 is provided near the drain port 15. I have.
The power lines of the first heating element H1 and the second heating element H2 are respectively connected to predetermined portions of a control circuit in an electric box (not shown) in the cooling unit 21.

In this embodiment, when the first heating element H1 provided on the dew receiving plate 9 is energized during defrosting, the dew receiving plate 9 is heated to melt the ice blocks. Drain port 15
The second heating element H2 provided near the heater is constantly energized to generate heat, and the temperature of the portion 20 near the drain port 15 downstream of the dew receiving plate 9 is warmed to the freezing point or higher. The frost does not freeze again. By selecting the amount of heat generated by the second heating element H2, even if some ice blocks remain on the dew receiving plate 9 when the defrosting time ends, the ice blocks are melted after the start of the cooling operation, It is also possible to drain.

Here, the first heating element H1, the second heating element H2, and the dew receiving plate 9 are slightly separated from the evaporator 7 and arranged below the evaporator 7, so that It is separated from the flow path of the cool air that reaches the outlet 12 through the evaporator 7. Therefore, during the cooling operation, the heat of the second heating element H2 which is always energized and the dew receiving plate 9 which is heated by the second heating element H2 are not easily taken away. It is possible to prevent the defrosted water and ice blocks that have melted and fallen from remaining on the dew receiving plate 9 to prevent the ice from growing during the next cooling operation and finally causing the dew receiving plate 9 to be deformed or damaged. it can.

Next, a cooling unit 22 according to a third embodiment of the present invention will be described with reference to FIG. In this embodiment, the first heating element H1 to be energized at the time of defrosting has a larger number of bent portions 10 at the downstream side of the dew receiving plate 9 than in the second embodiment.

Since a heating element having a constant heating value per unit length is usually used, according to the above configuration, the heating value of the exposure plate 9 on the upstream side of the first heating element H1 is smaller than that of the first heating element H1. The amount of heat generated on the downstream side is increased by the increase in the length of the bent portion 10. Therefore, since the downstream side is heated more than the upstream side, the flow is hindered by solids such as ice blocks and frost, and the defrost water and the ice blocks which are stagnant in the portion 20 near the drain port 15 are removed. Thus, the heat of the first heating element H1 is efficiently transmitted. Furthermore, since the temperature of the vicinity of the drain port 15 of the dew receiving plate 9 made of steel plate increases by heat conduction due to the heat of the first heating element H1, the drainage is smoothed.

The example of the heating element in which the amount of heat generated on the downstream side is increased by increasing the number of the bent portions 10 has been described. However, the present invention is not limited to this. For example, the amount of heat generated per unit length may be partially reduced. The amount of heat generated on the downstream side may be increased from that on the upstream side.

Further, since the second heating element H2 is always energized, the present invention can be practiced with a small heating value. Therefore, for example, a low-cost heating element such as a PVC cord heater in which a resistance wire is covered with a vinyl chloride resin or a silicon cord heater covered with a silicone resin is used, and a heat conductive material such as aluminum tape is provided on the lower surface of the exposure plate 9. If affixed with a good body, a low-cost cooling device can be provided, and since the heating element does not come into contact with the defrost water, problems such as corrosion can be avoided.

Further, the first heating element H1 is energized only at the time of defrosting. However, the power is not turned off at the same time as the end of the defrosting operation, and the first heating element H1 is delayed at the end of the defrosting operation. The power of the heating element H1 may be turned off.
That is, even if the defrosting operation is completed and the operation of the cooling device is started, there is a slight time delay before the defrosting water from the evaporator 7 flows to the dew receiving plate 9, and for a few minutes during that time. If the first heating element H1 is heated, the defrost water on the dew receiving plate 9 will not be re-frozen, and the drainage will be performed more smoothly.

In the above embodiment, one or two heating elements are used as the heating elements provided on the dew receiving plate 9. However, three or more heating elements may be used. Good.

In addition to the above structure, if a heat insulating material made of a foamed resin such as foamed polyethylene is attached to the lower surface of the dew receiving plate 9, the dew receiving plate 9 will not be cooled from the lower surface by the cool air in the cooling storage 1. Since the heat of the heating element provided on the dew receiving plate 9 is effectively transmitted to the dew receiving plate 9, re-freezing of water and ice blocks dropped on the dew receiving plate 9 can be further prevented.

[0027]

As described above, according to the first aspect of the present invention, even if a large amount of ice blocks are present in the portion near the drain port of the dew receiving plate, the ice blocks are melted and drained, and the dew receiving plate is formed. A cooling device that does not freeze again can be provided. Therefore, the cooling performance is not reduced due to the frost blockage of the evaporator above the dew receiving plate, and the dew receiving plate is not deformed or damaged by the growth of the re-frozen ice.

According to the second aspect of the present invention, there is no heat radiation from the first heating element during the cooling operation, and only the heat of the second heating element becomes the heat load during the cooling operation. Has little effect on performance. Further, since the portion near the drain port of the dew receiving plate is always warmed, there is no re-freezing of the defrost water in the portion near the drain port, and the drain can be reliably drained.

According to the third aspect of the present invention, the portion of the dew receiving plate close to the drain port where the defrost water is liable to re-freeze is heated by the first heating element in addition to the heating by the second heating element. Since the heat is generated by the heat generated by the large portion of the water, the ice blocks in the portion near the drain can be reliably melted and drained from the drain.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cooling storage according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the cooling unit according to the first embodiment;

FIG. 3 is a perspective view of a cooling unit according to a second embodiment.

FIG. 4 is a transparent perspective view of a cooling unit according to a third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cooling storage 2, 21, 22 Cooling unit 7 Evaporator 9 Dew receiving plate 10 Bending part 15 Drain port 20 Part H Heating element H1 First heating element H2 Second heating element

Claims (3)

[Claims] 1. A cooling device comprising an evaporator provided in an insulated box and a dew receiving plate provided below the evaporator and having a drainage port, the amount of heat generated in a portion near the drainage port. A cooling device, wherein a heating element having a large size is provided on the dew receiving plate. 2. A cooling device comprising: an evaporator provided in an insulated box; and a dew receiving plate having a drain port and provided below the evaporator, wherein the dew receiving plate has A cooling system, comprising: a first heating element to be energized; and a second heating element to be constantly energized, and the second heating element is disposed closer to the drain port than the first heating element. apparatus 3. The cooling device according to claim 2, wherein the first heating element generates a large amount of heat at a portion near a drain port of the dew receiving plate.