JPH08159642A - Defrosting device of evaporator of cold air holding device - Google Patents

Abstract

PURPOSE: To enable an efficient defrosting to be carried out for a short period of time by a method wherein a halogen heater is used as a heater. CONSTITUTION: As a defrosting heater, a cylindrical halogen heater 8 is arranged at an upper part of an evaporator 2 and further a recess-shaped reflection plate 9 is arranged at an upper part of it. With such an arrangement as above, a higher radiation energy than that of a far infra-red ray heater can be attained and a frosting is directly defrosted by a radiation heat, resulting in that the defrosting time is shortened. As the halogen heater 8, energy having a peak value of energy distribution set from a visible range to a near far infrared ray is used to cause an initial melting effect can be improved and a characteristic of the halogen heater 8 is realized by increasing a rate of permeation as the melting state is proceeded. Then, the evaporator 2 has a structure in which the surface of the connecting pipe 10 is provided with several fins 11 and then the surface is treated with a selective absorption surface treatment for efficiently absorbing energy radiated by the halogen heater 8 and for generating heat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defrosting device for an evaporator for a cooler for removing frost attached to an evaporator used in a cooler such as a refrigerator, a refrigerator, a freezer and a freezer. .

[0002]

2. Description of the Related Art Generally, in an evaporator used in a cold storage device such as a freezer, a phenomenon in which ambient water is cooled and adheres as frost to grow on the surface of the evaporator is observed. When frost grows on the surface of the evaporator, the function of the evaporator deteriorates.
A defrosting device for melting and removing adhered frost is provided near the evaporator.

[0003] Fig. 4 is a front view (Fig. A) showing a top part of a conventional domestic refrigerator-freezer and a side sectional view (Fig. B), showing a lower part of an evaporator 2 installed in a freezer compartment 1. An example of a configuration in which a defrosting device including an infrared heater 3, a protective cover 4 and a drain pan 5 is arranged is shown.

Normally, the cool air from the evaporator 2 is sent into the freezer compartment 1 via the fan 6, but if frost adheres to the outer periphery of the evaporator 2, the fan 6 stops and the cool air is provided below the evaporator 2. The infrared heater 3 is energized.

The infrared heater 3 has its outer periphery protected by a glass tube, and a metallic protective cover 4 is provided right above the glass tube so that water drops do not come into contact with and damage the glass tube when the temperature is high. .

When the infrared heater 3 is electrically heated, the surrounding air is heated and rises by convection to melt the frost adhering to the surface of the evaporator 2. The melted water drop falls into the drain pan 5 and is discharged to the outside of the refrigerator via the conduit 7.

[0007]

In the conventional defrosting apparatus, air heated mainly on the surface of the infrared heater 3 reaches the surface of the evaporator 2 by convection to melt the frost in the vicinity. The heating efficiency is poor because air with poor thermal conductivity is used as a medium, and considerable heat leakage occurs in the low-temperature freezer, resulting in a large energy loss, and a long defrosting time is required for the input energy. Was there. Therefore, not only the defrosting power consumption becomes large, but also the following disadvantages occur.

Since the cooling operation is stopped at the time of defrosting, the interior of the refrigerator warms up and the cooling load increases in proportion to the defrosting time. For this reason, the power consumption for cooling to the set cool temperature after defrosting increases. Due to the inflow of the heated air during defrosting, the recooling heat load after defrosting increases by that amount. The inflow of heated air for defrosting is added to the stop of cooling during defrosting, which causes a rise in the temperature of foods stored in the refrigerator and the like, which accelerates the deterioration of the quality of cold-insulated products.

As described above, in the conventional defrosting apparatus, since the defrosting is mainly performed by heating and raising the temperature of air, it is indirect, large in heat loss, and low in efficiency. Therefore, it is an object of the present invention to provide a defrosting device for an evaporator for a cooler that can remove frost efficiently in a short time.

[0010]

According to the present invention, a heater is a halogen heater in a defrosting apparatus for melting and removing frost adhering to an evaporator by disposing a heater near the evaporator. .

Further, in this case, the halogen heater is characterized in that the peak value of its wavelength-radiation energy characteristic is in the near infrared region.

Further, in this case, the halogen heater is arranged above the evaporator.

Further, in this case, the evaporator is characterized in that the surface thereof is subjected to a selective absorption surface treatment for selectively absorbing the radiant energy of the halogen heater.

[0014]

In the structure of the present invention, by using the halogen heater as the heater, it is
Radiant energy of 0 ² to 10 ⁵ times is obtained, and frost is directly melted by radiant heat, so that the defrosting time is shortened.

The frost layer is in the visible light range (0.34 μm to 0.76).
μm) has a high reflectance and absorbs in the near infrared region. Therefore, by using a halogen heater having a peak value of wavelength-radiation energy characteristics in the near infrared region, the initial melting effect is enhanced, and the progress of melting progresses. The characteristics of the halogen heater are exhibited due to the accompanying increase in transmittance.

Further, by providing the halogen heater on the upper portion of the evaporator, the frost on the upper portion of the evaporator is melted first, and the melted water is dropped to sequentially melt the frost on the lower portion, so that the melting time is extremely shortened. To be done.

Further, by subjecting the surface of the evaporator to the selective absorptive surface treatment, the selective absorptive surface treated layer is directly heated due to the increase in the transmittance with the progress of melting, whereby the entire evaporator is thermally conductive. As a result of being heated by, the frost is melted from the inside as well, and the defrosting time is shortened.

[0018]

FIG. 1 is a constitutional view showing an embodiment in which the defrosting device for an evaporator for a cold storage device according to the present invention is applied to a freezing chamber of a domestic refrigerator-freezer, in which (a) is a front view and (b) is ) Is a side sectional view. The same components as those shown in FIG. 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

In this embodiment, a cylindrical halogen heater 8 is used as a defrosting heater in place of the conventional infrared heater, the halogen heater 8 is provided on the upper part of the evaporator 2, and a concave surface is provided on the upper part thereof. The reflector 9 is provided.

FIG. 2 shows “wavelength (μm) -radiant energy (W / m ² · μ” of the infrared heater and the halogen heater.
m) ”characteristic curve diagram, as is clear from this characteristic diagram,
It can be seen that the halogen heater radiates about 10 ² to 10 ⁵ times as much energy as the infrared heater. The halogen heater 8 of this embodiment has an energy distribution peak value of 0.3.
Those in the visible to near-infrared region of 4 to 3.0 μm are used.

Particularly, the frost layer is in the visible light range (0.34 to
0.76 μm), the reflectance is high and the transmittance is low, so that the peak value is 1.0 μm more than that having characteristics such as the halogen heater A in the visible light region having the peak value of 0.5 μm.
It is preferable to use a heater having characteristics such as the halogen heater B in the near infrared region.

Then, at the start of defrosting, the energy efficiency of the halogen heater is relatively low against the melting of frost, but since there is absorption in the near infrared region, the transmittance increases as the melting of frost progresses. However, the characteristics of the halogen heater are exhibited.

3A and 3B are configuration diagrams of the evaporator 2. FIG. 3A is a front view and FIG. 3B is a side view. As shown in the figure, the evaporator 2 has a structure in which a large number of fins 11 are provided on the surface of a continuous tube 10. The surface efficiently absorbs the energy emitted by the halogen heater 8 to generate heat. The selective absorption surface treatment is applied.

The selective absorption region coincides with most of the radiant energy wavelength of the halogen heater 8, which is 0.34 to 3.0 μm, and the absorptance thereof is 0.94, which is 3.0 to 25.0 in the infrared region.
An emissivity of about 0.2 for μm can be obtained. Therefore, the radiant energy of the halogen heater 8 is efficiently absorbed and converted into heat, and the radiation in the infrared region is very small, and the absorbed heat is not released, so that the evaporator 2 can be effectively used.
Can be defrosted by heating.

This selective absorptive surface treatment is similar to that used for the surface treatment of the heat collecting plate of the solar collector, for example,
It can be treated by a secondary electrolytic coloring method, a plating method, a chemical conversion treatment method, a coating method, or the like. When the evaporator 2 is made of aluminum, the secondary electrolysis method is most suitable, but the selective adsorption paint may be applied. Since the film formed by these treatments is as thin as about 1 μm, there is no fear of adversely affecting the heat exchange performance of the evaporator 2.

The reflecting plate 9 is a concave reflecting plate provided on the upper portion of the halogen heater 8 so as to cover the rear surface thereof, and is for radiating the radiant energy of the halogen heater 8 to the evaporator 2 effectively. The surrounding wall surface of the evaporator 2 has a reflectance of 95.
If it is covered with an aluminum thin plate of about%, the amount absorbed and permeated by the peripheral wall surface of the evaporator 2 is reduced, and the effect is further promoted.

In this structure, the fan 6 is operated during normal operation.
Is operated, and the cool air generated from the evaporator 2 is fed into the freezer compartment 1. When a large amount of frost forms on the surface of the evaporator 2 due to this refrigeration operation and defrosting is required, the cooling operation of the refrigeration cycle and the operation of the fan 6 are stopped, and instead, it is placed on the top of the evaporator 2. The halogen heater 8 provided is energized.

The halogen heater 8 energized has a wavelength of 1 μm.
Light energy in the visible to near-infrared region having a peak value of radiant energy in the vicinity of m is irradiated and reflected by the reflection plate 9 so that the frost in the uppermost row of the evaporator 2 is first melted. As the transmittance increases, the light energy transmitted through the wet frost (or ice) also starts heating the surface of the evaporator 2.

Thus, when the surface of the evaporator 2 is exposed,
Since the surface thereof is subjected to the selective absorptive surface treatment that has a high absorption rate of light energy and a low emissivity of heat, the radiant energy of the halogen heater 8 is efficiently converted into heat and the evaporator 2 itself is heated. , The frost attached to the fins 11 in the lower row is sequentially melted by heat conduction, and the defrosting effect by dropping the melted water is also added to sequentially accelerate the defrosting speed.

Further, since the exposed area of the evaporator 2 increases as the melting progresses, the heated area also increases, and the melting of frost is completed while being accelerated. The water thus melted is successively dropped into the drain pan 6 and collected, and discharged via the conduit 7 to the outside of the refrigerator.

As described above, according to the present invention, defrosting by the high energy halogen heater 8, defrosting by arranging the halogen heater 8 above the evaporator 2 by dripping defrosting molten water, and selective absorption. The defrosting by heating and melting from the inner surface side by the heating of the evaporator 2 which has been subjected to the functional surface treatment acts individually or synergistically, and the defrosting time is extremely shortened.

In the above-described embodiment, the case where the present invention is applied to a home refrigerator / freezer has been described. However, the present invention is not limited to this. It can be applied to defrosting evaporators in cold storages, defrosting evaporators in refrigerated warehouses or frozen warehouses.

[0033]

According to the present invention, as a result of the extremely short defrosting time, the heat load due to the cooling stop of the cooler and the heat load due to the heat leakage of the defrosting heater are both reduced.
Not only is the energy required for recooling reduced by that much to save energy, but also the temperature fluctuations in the cooler are reduced due to the high efficiency of defrosting, so the effect of delaying the deterioration of the quality of the cooled product can be obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a defrosting device according to the present invention, (a) is a front view and (b) is a side sectional view.

FIG. 2 is a wavelength-radiant energy characteristic curve diagram of a heater.

FIG. 3 is a configuration diagram of an evaporator, in which (a) is a front view and (b) is a side view.

FIG. 4 is a configuration diagram of a conventional defrosting device, (a) is a front view,
(B) is a side sectional view.

[Explanation of symbols]

 1 Freezer 2 Evaporator 5 Drain pan 6 Fan 7 Conduit 8 Halogen heater 9 Reflector

Claims (4)

[Claims] 1. A defroster for arranging a heater in the vicinity of an evaporator to melt and remove frost adhering to the evaporator, wherein the heater is a halogen heater. Defroster. 2. The defroster for an evaporator for a cooler according to claim 1, wherein the halogen heater has a wavelength-radiation energy characteristic peak value in a near infrared region. 3. The defroster for an evaporator for a cooler according to claim 1 or 2, wherein the halogen heater is disposed above the evaporator. 4. The evaporator has a surface subjected to a selective absorptive surface treatment for selectively absorbing the radiant energy of the halogen heater.
7. A defrosting device for an evaporator for a cooler according to any one of 1.