JPS5852154B2 - refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigerator with a new structure that defrosts the refrigerator without a defrosting heater.

In conventional refrigerators, as shown in FIG. 1, an electric heater 6 is added to the evaporator 1 to remove frost from the evaporator 1, and a large input power (100 W or more) is applied to the evaporator 1.

For this reason, the heater input valve consumes extra electricity, and the compressor 2 has to be operated extra by the heating of the evaporator and its surroundings.If the electricity consumption increases, the defrosting ends due to the large power input. There is a drawback in that when the temperature sensor malfunctions, it remains energized, which can be dangerous and cause a fire.

In addition, as a countermeasure to these problems, there was a method called hot gas defrosting that used high-temperature gas from the refrigeration cycle, but it required a solenoid valve to switch the pipeline, and the valve structure was complex and had moving parts, making it unreliable. These valves are rarely used in recent years because they have shortcomings in performance and longevity, and the valves are expensive.

The object of the present invention is to provide a device which eliminates the above-mentioned drawbacks, does not use a defrosting heater, does not have moving parts such as valves, has a simple structure, is highly reliable, and is inexpensive.

The present invention will be explained below with reference to Examples.

FIGS. 2 and 3 are diagrams showing one embodiment of the present invention, with FIG. 2 showing the operating situation when defrosting is not being performed, and FIG. 3 showing the operating situation when defrosting is being performed.

In FIG. 2, a compressor 2, a condenser 3, a compression regulator (capillary, expansion valve, etc.) 4, an evaporator 1, and a return pipe 5 constitute a refrigeration cycle to cool a refrigerator (not shown).

Up to this point, there is no difference from before. The present invention has the following points.

A heating section 8 in thermal contact with the compressor 2, a cooling section 10 in thermal contact with the evaporator 1, a tank 11 as a liquid storage section, a riser pipe 12, and a connecting pipe 7 connecting these. ．． 9.13
to form a closed loop, and the tank 11 is filled with a low boiling point liquid (refrigerant R
-12, R-11, R-114, etc.) 14 is enclosed.

The height of the riser pipe 12 is set higher than the liquid level in the tank 11 to prevent the liquid from overflowing.

Further, a heating device (such as an electric heater or a warm air fan) 15 is added to the riser pipe.

First, we will explain what happens when defrosting is not performed.

Until the defrosting start signal is received, the heating device 15 is stopped and the low boiling point liquid 14 accumulates in the tank 11 and does not overflow from the riser pipe 12 and flow into the heating section 8, so the heating section becomes empty. The only heat transfer between the heating section 8 and the cooling section 10 is the heat conduction of the tube wall and the natural convection of the gas within the tube, both of which are small, and almost no heat is transferred to the evaporator 1.

Next, when a defrosting start signal is received from a frost detector, a compressor operation time integration timer, etc., the heating device 15 is activated and the riser pipe 1 is activated.
Heat 2.

At this time, as shown in FIG. 3, the liquid 14 inside the riser 12 boils and generates bubbles 17, and the liquid 14 overflows from the top of the riser 12 due to the pump action when the bubbles rise.

The overflowing liquid passes through the downcomer pipe 1, enters the heating section 8, and boils due to residual heat of the compressor of 80°C or higher received from the compressor 2, turns into steam, passes through the riser pipe 9, reaches the cooling section 10, and condenses. The latent heat is transferred to the evaporator 1 to perform defrosting.

At this time, the compressor is also cooled, but because of its large heat capacity, the temperature drop is only small (about 10° C.).

In this manner, by utilizing the bubble pump action in the riser pipe 12 to operate and stop the heating device 15, a defrosting method without any moving parts was obtained.

In order to effectively perform the bubble pumping action, the top of the riser pipe 12 of the tank 11 is connected to a pressure communication pipe 13 as shown in the figure.
Although it is desirable to equalize the pressure between the two by connecting the two, the effects of the present invention will not be lost even if there is no communicating pipe.

Further, if the internal volume of the cooling pipe 10 is large enough to accommodate the liquid 14, the tank 11 may be omitted, and the liquid storage section may be configured with only the connecting pipe.

According to experiments, refrigerant R-12 was used as the low boiling point liquid 14, the amount of the sealed liquid was 1001, and the heating device 1 was heated to the height of the riser 12 to 100.
By using an electric heater as No. 7 and applying electricity to the heater at a heater input of 5 W, defrosting could be performed in about 20 minutes.

FIG. 4 shows another embodiment of the present invention, in which the liquid in the tank is contained and overflowed by the vapor pressure of the liquid.

That is, the height of the riser pipe 12 is set higher than the liquid level in the tank 11 so that the liquid 14 is normally stored in the tank 11 and does not overflow from the riser pipe 12. When the tank 11 is heated by supplying electricity, the vapor pressure of the liquid 14 increases, pushing down the liquid level in the tank 11 and causing the liquid to overflow from the riser pipe 12.

In this way, it was possible to control whether or not heat from the compressor 2 was transferred to the evaporator 1 by turning on or not energizing the heating device 15.

FIG. 5 shows another embodiment of the present invention, in which a lighting device 15 is added in the middle of the downcomer pipe 7 from the tank 11, and the air bubbles 17 generated when energized rise upward in the opposite direction to the flow. block the flow.

For this reason, it is desirable that a part of the downcomer pipe 7 has a small diameter, and according to experiments, it was possible to stop the liquid from falling by heating a pipe with an inner diameter of 1 m using a 6W electric heater.

FIG. 6 shows another embodiment of the present invention, in which a permanent magnet 18 is placed inside a tank 11, and a material 16 whose magnetic flux density changes depending on temperature (temperature-sensitive ferrite, etc.) 16 and a heating device 1 are placed above the tank 11.
5 is the installation.

When the heating device 15 is not energized, the substance 16 and the permanent magnet 1
8 are attracted to each other, and the permanent magnet 18 is floating above the tank.

At this time, the liquid 14 does not overflow from the tank 11.

When the heating device 15 is energized, the substance 16 loses its magnetism and no longer attracts the permanent magnet 18, and the magnet 18 falls into the liquid 14 and sinks.

At this time, the liquid level rises and the liquid overflows from the tank 11 and flows into the heating section 8.

In this way, heat from the compressor 2 can now be transferred to the evaporator 1 simply by energizing the heating device 15 during defrosting.

The relationship between the permanent magnet 18 and the substance 16 may be a piece of iron and an electromagnet, a piece of iron and a temperature sensing element, or anything that can be magnetically attracted.

In the above embodiments, the shape of the evaporator may be any shape, such as a fin tube or a box-shaped evaporator, and it goes without saying that the shape is not limited to the type.

As described above, according to the present invention, it is possible to obtain a refrigerator that requires almost no electrical input, consumes little power, and has little risk of fire.

[Brief explanation of drawings]

Figure 1 is a diagram showing the structure of the refrigeration cycle of a conventional refrigerator.
FIGS. 2 and 3 are structural diagrams showing an embodiment of the present invention, and FIGS. 4 to 6 are structural diagrams showing other embodiments.

Claims (1)

[Claims] 1. In a refrigerator equipped with a refrigeration cycle including a compressor, a condenser, and an evaporator, a heating section and a cooling section that are in thermal contact with the compressor and the evaporator, respectively, and liquid storage located near the bottom of the evaporator. and a closed container composed of a connecting pipe connecting the heating section, the cooling section, and the liquid storage section, further providing means for heating a part of the liquid in the liquid storage section,
A low boiling point liquid is sealed in the sealed container in an amount smaller than the volume of the sealed container, and the low boiling point liquid is supplied to the heating section only when the heating means is heated, and the heat of the compressor is transferred to the evaporator and removed. A refrigerator characterized by frosting.