JPH07190597A - Defrosting device in freezer type refrigerator - Google Patents

Abstract

PURPOSE:To prevent defrosting performance from being decreased by a method wherein an operation of a compressor is stopped when a cooling device is defrosted, a defrosting heater is electrically energized and at the same time a first opening or closing valve and a second opening or closing valve are concurrently closed to cause an inside area of the cooling device to be defrosted while being separated. CONSTITUTION:A compressor 23 stops its operation when a temperature within a freezer type refrigerator is cooled down to its predetermined temperature. At this time, since a discharged pressure from the compressor 23 is eliminated, a pressure within an auxiliary container 36 is reduced and an inner pressure of a first bellows 35 is also decreased. Due to this fact, a slide valve within a changing-over valve 32 is pushed by a force of a spring member 34 to close an opening at an expansion valve 25 with a first opening or closing valve 28 and an opening at a suction pipe 26 with a second opening or closing valve 30. A third opening or closing valve 41 is moved to cause a refrigerant flowing-in pipe 27 and a refrigerant discharging port 29 to be short circuited and connected from each other, resulting in that an inner side of the pipe of the cooling device 6 is separated from it. Then, the refrigerant within the pipe of the cooling device 6 is left at it is. In this way, the separation of the cooling device 6 enables the flowing-in of the refrigerant to be prohibited and a useless increase in temperature of the cooling device 6 is prevented.

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 efficiently removing frost adhering to a refrigerator of a refrigerator / freezer.

[0002]

2. Description of the Related Art Conventionally, a refrigerator for household use takes in outside air having a relatively high temperature and a high absolute humidity each time the door is opened and closed. However, there is a problem that the heat transfer efficiency is lowered by hindering the heat exchange between the evaporator surface and the air in the freezer / refrigerator. Therefore, as a solution, a method in which a defrost heater is attached in the vicinity of the evaporator, electricity is passed through the defrost heater each time frost is accumulated, and the heat is used to defrost is generally put into practical use.

In recent years, this defrost heater can also be used as a heater for regenerating by heat, an odor adsorbent that removes unpleasant odors from foods such as vegetables, meat and fish stored in a refrigerator-freezer. It is getting more and more. For example, there is a freezer-refrigerator with a deodorizing device described in JP-A-2-97882.

A freezer-refrigerator in which the above-described conventional defrost heater is applied to a deodorizing device will be described below with reference to FIGS. 9 to 13.

Reference numeral 1 is a freezer-refrigerator body, and a freezer compartment 2 and a refrigerator compartment 3 are provided.
And a door 4 of the freezer compartment 2 and a door 5 of the refrigerator compartment 3. Reference numeral 6 denotes a cooler arranged in the cooler room 7 at the back of the freezer compartment 2 and supplies a part of the air cooled by the cooler 6 by the fan 8 into the freezer compartment 2 from the supply port 9 to further freeze the air. The freezing chamber 2 is cooled by repeating the cooling circulation returning to the inside of the cooler chamber 7 via the air return duct 10 in the chamber 2.

A part of the air cooled by the cooler 6 is supplied into the refrigerating compartment 3 via the supply duct 11, and the air in the refrigerating compartment 3 is supplied via the return duct 12 to the cooler compartment 7.
The refrigerating chamber is cooled by repeating the cooling circulation returned to the inside.

Reference numeral 13 denotes a defrost heater which is disposed below the cooler 6 in the lower part of the cooler chamber 7. The defrost heater 13 is made of, for example, a glass tube heater and is energized only when the cooler 6 is defrosted. ON / OFF control is performed. Further, 14 is an adsorbent arranged near the upper part of the defrosting heater 13 for deodorization, and an adsorbent such as activated carbon and a thermal decomposition catalyst such as platinum or nickel are formed on the solid plate.

Reference numeral 15 denotes a roof member arranged on the upper surface side of the adsorbent 14, which is made of a metal plate such as aluminum having heat resistance and water resistance.
As shown in FIG. 1, the container has a shallow container shape with an open lower side, and covers the side of the adsorbent 14 opposite to the defrost heater 13 side, that is, the upper surface.

Reference numeral 16 is a heat insulating material provided between the roof member 15 and the adsorbent 14, and is formed on a thin plate by spinning of glass fibers, for example. The adsorbent 14
The roof member 1 with the heat insulating material 16 sandwiched over the entire upper surface thereof.
5, the defrosting heater 13 is supported on both ends of the roof member 15 in the longitudinal direction by a supporting member 17 supporting the defrosting heater 13 on the wall surface of the cooler chamber 7 as shown in FIG. By doing so, it is attached above the defrost heater 13.

Reference numeral 18 is a bimetal thermometer mounted near the upper part of the cooler 6 for detecting the end of defrosting.

The operation of the defroster for a refrigerator-freezer constructed as above will be described. During the cooling operation, the air in the refrigerator is circulated through the cooler chamber 7, the freezing chamber 2 and the return duct 10 by the blowing action of the fan 8, and the cooler chamber 7, the supply duct 11, the refrigerating chamber 3 and It is circulated through the return duct 12.

At this time, the air passing through the inside of the cooler chamber 7 is as shown in FIG.
The air flow 19 shown in FIG. 2 comes into contact with the adsorbent 14, and the odorous component contained in the air is adsorbed by the adsorbent 14.

Moisture contained in the outside air that has entered by opening and closing the door 4 of the freezer compartment 2 and the door 5 of the refrigerating compartment 3 is condensed on the outer surface of the cooler 6 having the lowest temperature to form frost, and thus the cooler. Attach to 6.

The frost that has adhered and accumulated has a cooler 6 and a cooler chamber 7.
In order to prevent heat exchange with the air flowing through, the defrost heater 13 is normally energized to perform the defrost operation after a certain interval.

When the defrosting operation is started, the cooling operation of the cooler 6 and the operation of the fan 8 are stopped, while the defrosting heater 13 is energized to heat the defrosting heater 13 as shown in FIG. Linear radiative heat transfer 20 and convective heat transfer 21 are generated.

The convective heat transfer 21 therein heats the cooler 6 for defrosting, and at the same time, the linear radiant heat transfer 20 heats the adsorbent 14.

The adsorbent 1 having a high temperature due to this radiation heat transfer
In No. 4, the adsorbed odor component is released, and at the same time, the contained odor component is thermally decomposed and removed by the catalyst such as platinum or nickel contained therein, and the adsorption function is regenerated.

At this time, the roof member 15 is the defrost heater 1
The heat from 3 is confined downward to efficiently heat the adsorbent 14 and also prevents defrost water from directly falling onto the adsorbent 14 and the defrost heater 13.

The heat insulating material 16 suppresses the heat of the adsorbent 14 from being radiated from the roof member 15 made of metal and having good heat conductivity,
In addition, defrosting water drops on the roof member 15 and the roof member 1
The heat shock of the adsorbent 14 due to the rapid cooling of 5 is prevented.

[0020]

However, in the above configuration, the roof member 15, the heat insulating member 16 and the adsorbent 14 are present as inclusions in the space between the defrost heater 13 and the cooler 6. Therefore, the linear radiant heat transfer 20 generated from the defrost heater 13 is cut off, and only the convective heat transfer 21 removes the frost adhering to the cooler 6.

Therefore, in particular, it is difficult for heat to reach the upper part of the cooler 6, the heat transfer efficiency is deteriorated, the defrosting time until the bimetal thermostat 18 detects the completion of defrosting becomes longer, and the amount of electric power becomes large. The temperature rises significantly, which has the drawback of affecting the preservation of foods.

The present invention solves the above-mentioned conventional problems, and provides a defrosting device for a freezer-refrigerator that improves the heat transfer efficiency to the cooler of the defrosting heater and prevents the defrosting performance of the refrigerator from decreasing. The purpose is to

[0023]

In order to achieve this object, the defrosting device of the present invention is a refrigeration cycle in which refrigerant is discharged from a compressor and returned to the compressor through a condenser, an expansion valve, a cooler, and a suction pipe. A defrosting heater having a first opening / closing valve at the refrigerant inlet and a second opening / closing valve at the refrigerant outlet to the cooler, and a defrost heater incorporating an electric resistor is installed at the bottom of the cooler to remove the defroster of the cooler. During frost, the operation of the compressor is stopped, the defrost heater is energized, and the first on-off valve and the second on-off valve are simultaneously closed to defrost the interior of the cooler.

Further, it has a third opening / closing valve which can connect the refrigerant inlet and the refrigerant outlet of the cooler, and when defrosting the cooler, stops the operation of the compressor and energizes the defrost heater and The on-off valve and the second on-off valve are closed at the same time, and the third on-off valve is opened to defrost the inside of the cooler in an isolated state.

Further, at a predetermined position, the expansion valve and the refrigerant inlet to the cooler are connected to each other, and the suction pipe and the refrigerant outlet from the cooler are connected to each other. With the valve, the opening portion on the suction pipe side is closed with the second opening / closing valve, and the third opening / closing valve integrally connecting the refrigerant inlet port and the refrigerant outlet port of the cooler is short-circuited, and the switching is performed by the slide unit and the drive unit. The valve is provided in the cooler.

Further, as a slide valve drive mechanism, one side of the slide valve has a first bellows that expands and contracts due to internal pressure, and a spring member is provided on the opposite side of the first bellows, and is built in the first bellows and the discharge side of the compressor. A switching valve having a drive mechanism that drives a slide valve by injecting a non-condensable gas into the drive unit composed of the second bellows and the connecting pipe and utilizing the pressure change at the time of compressor operation and at the time of stop was installed. It is configured.

[0027]

With this structure, the liquid refrigerant contained in the cooler is heated by the defrosting heater located in the lower part, evaporates in the lower layer in the cooler tube and moves to the upper layer.
In the upper layer portion, it is cooled by frost adhering to the outer surface of the cooler, the gaseous refrigerant condenses into a liquid, and moves to the lower layer portion by its own weight.

By repeating this, efficient heat exchange between the lower layer portion and the upper layer portion is performed inside the cooler, so that the frost attached to the outer surface of the upper layer portion of the cooler is also heated by the heat of the defrost heater. It melts and defrosts very quickly and efficiently. In particular, by short-circuiting the refrigerant inlet and outlet of the cooler, the refrigerant pipe becomes a loop and the gas refrigerant and liquid refrigerant move more smoothly, and the number of parts is increased by integrating the three on-off valves. It is possible to make the target operation surely easy with a single operation. Further, by utilizing the pressure change when the compressor is operating and when it is stopped, the slide valve can be reliably driven and the power saving defrosting device can generate a relatively small amount of electricity.

[0029]

EXAMPLES Examples of the present invention will be described below with reference to FIGS.
Follow the explanation below. The cooling device, the defrosting heater, the deodorizing adsorbent, and the like are attached to the freezer-refrigerator in the same structure as in the conventional example, and therefore the drawings and detailed description thereof are omitted.

Reference numeral 22 is a refrigeration cycle system in which the refrigerant is discharged from the compressor 23 and returns to the compressor 23 via the condenser 24, the expansion valve 25, the cooler 6 and the suction pipe 26.

A first opening / closing valve 28 is provided at the refrigerant inlet 27 of the cooler 6, and a second opening / closing valve 30 is provided at the refrigerant outlet 29.

A defrosting heater 13 having an electric resistor built therein is installed under the cooler 6 as in the conventional example, so that the defrosting heater 13 is energized only when the defroster is defrosted, and the rest is cut off. The on / off control is performed by 31. Further, as in the conventional example, an adsorbent 14 having an adsorbent such as activated carbon and a thermal decomposition catalyst such as platinum or nickel formed on a solid plate is disposed near the upper portion of the defrost heater 13 for deodorization. A roof member 15 is arranged on the upper surface side of the adsorbent 14 and is made of a metal plate such as aluminum having heat resistance and water resistance. As shown in FIGS. 10 and 11, the roof member 15 has a shallow container shape with an open lower side, and covers the side of the adsorbent 14 opposite to the defrost heater 13 side, that is, the upper surface. There is.

Similar to the conventional example, the roof member 15 and the adsorbent 14
A heat insulating material 16 formed on a thin plate by the weaving of glass fibers is provided between and, and the adsorbent 14 and the roof member 15 are attached with an adhesive or the like with the heat insulating material 16 sandwiched therebetween. As shown in FIG. 11, the supporting members 17 supporting the defrosting heater 13 on the wall surface of the cooler chamber 7 at both ends thereof support both ends of the roof member 15 in the longitudinal direction, so that the defrosting heater 13 is above the defrosting heater 13. Is attached to.

Reference numeral 18 denotes a bimetal thermometer mounted near the upper portion of the cooler 6 for detecting the completion of defrosting.

32 is the first on-off valve 28 and the second on-off valve 3
Is a switching valve that accommodates a slide valve 33 integrally formed with 0, a spring member 34 is disposed on one side in the moving direction of the slide valve 33, and a first bellows 35 that expands and contracts due to internal pressure is provided on the other side. Is installed.

The first bellows 35 is the compressor 2
The second bellows 37 contained in the auxiliary container 36 in the refrigeration cycle system 22 on the discharge side 39 of 3 is connected by the connecting pipe 38 to form the drive unit 40, and the inside is filled with the non-condensable gas. .

That is, the slide valve 33 has a spring 34.
The switching valve 32 is provided with a drive mechanism that is driven by the first bellows 35 that expands and contracts due to a pressure difference generated when the compressor 23 is operated and stopped.

The slide valve 33 separates the refrigerant inlet 27 and the refrigerant outlet 29 of the cooler 6 when the compressor 23 is in operation, and when the compressor 23 is stopped, the slide valve 33 is driven to connect the refrigerant inlet 27 and the refrigerant outlet 29. The third on-off valve 41 to be interlocked is also provided integrally.

The operation of the defroster for a freezer-refrigerator constructed as above will be described below.

First, when the compressor 23 operates, the refrigerant such as CFC filled in the refrigeration cycle system 22 is compressed and discharged from the discharge port 39. The discharged refrigerant is a high-pressure gas with a high temperature of 100 ° C. or higher, but the condenser 2
It is cooled to 40 to 50 ° C at ambient temperature in 4 and becomes liquid.

When the liquid refrigerant passes through the expansion valve 25 which is composed of a capillary with a narrowed flow rate, the pressure suddenly drops and the liquid begins to vaporize. In the cooler 6, heat of vaporization is taken from the outside to cool the cooling chamber 7. To cool.

The vaporized refrigerant passes from the discharge port 29 of the cooler 6 through the suction pipe 26 and returns to the compressor 23.

During the refrigerant circulation in the refrigeration cycle, the slide valve 33 of the switching valve 32 causes the compressed refrigerant discharged from the discharge side 39 by the operation of the compressor 23 to increase the pressure in the auxiliary container 36 to compress the second bellows 37, and its force is exerted. Is the first bellows 35, the connecting pipe 38, and the second bellows 3.
Pressure is applied to the non-condensable gas filled in 7 and 7 to inflate the first bellows 35 and overcome the force of the spring member 34 pushing the slide valve 33 from the opposite side to push it to a predetermined position during compressor operation. (See FIG. 2) At this predetermined position, the expansion valve 25 and the refrigerant inlet 2 of the cooler 6
7, the refrigerant outlet of the cooler 6 and the suction pipe are interlocked, and as described above, the refrigerant can smoothly circulate in the refrigeration cycle system.

When the cooler chamber 7 is cooled by the cooler 6, a part of the air cooled by the fan 8 is supplied into the freezing chamber 2 through the supply port 9, and the air return duct 10 in the freezing chamber 2 is further supplied.
The freezing chamber 2 is cooled by repeating the cooling circulation returning to the inside of the cooler chamber 7 via.

A part of the air cooled by the cooler 6 is supplied into the refrigerating chamber 3 via the supply duct 11, and the air in the refrigerating chamber 3 is supplied via the return duct 12 to the cooler chamber 7.
The refrigerating chamber 3 is cooled by repeating the cooling circulation returned to the inside.

The compressor 23 continues to operate until the freezing compartment 2 and the refrigerating compartment 3 are sufficiently cooled, but stops when the internal temperature is cooled to a predetermined temperature. At this time, since the discharge pressure of the refrigerant from the compressor 23 disappears, the auxiliary container 3
The pressure in 6 decreases, and the internal pressure of the first bellows 35 also decreases.
Therefore, the slide valve 33 in the switching valve 32 is pushed by the force of the spring member 34 as shown in FIG.
The side opening is closed by the first opening / closing valve 28, the opening on the suction pipe 26 side is closed by the second opening / closing valve 30, and the third opening / closing valve 41 is moved to short-circuit the refrigerant inflow pipe 27 and the refrigerant outlet 29. Then, the inside of the cooler 6 tube is isolated in a loop shape.

Refrigerant in the cooler 6 pipe which is in the isolated state due to the stop of the compressor 23 stays as it is, and when there is no switching valve 32, the high temperature high pressure refrigerant flows into the cooler from the high pressure side of the suction pipe 26, Although the cooling efficiency is reduced, it is possible to prevent the inflow by isolating the cooler and prevent an unnecessary temperature rise of the cooler.

When the cooling operation is continued for a long time, the moisture contained in the outside air that has entered by opening and closing the door 4 of the freezing compartment 2 and the door 5 of the refrigerating compartment 3 is reflected on the outer surface of the cooler 6 having the lowest temperature. Condensation forms frost and deposits on the cooler 6.

Therefore, the defrosting heater 13 is normally provided at regular intervals.
Is energized and defrosting operation is performed. When the defrosting operation is started, the cooling operation of the cooler 6 and the operation of the fan 8 are stopped, while the defrosting heater 13 is energized to heat the defrosting heater 13 and linearly move as shown in FIG. Radiative heat transfer 20 and convective heat transfer 21 are generated.

The convective heat transfer 21 therein heats the cooler 6 for defrosting, and at the same time, the linear radiant heat transfer 20 heats the adsorbent 14.

The adsorbent 1 which has reached a high temperature due to this radiative heat transfer
No. 4 releases the adsorbed odor component, and at the same time, thermally decomposes and removes the odor component by the contained catalyst.
The adsorption function is regenerated. At this time, the roof member 15 plays a role of efficiently confining the heat from the defrost heater 13 to heat the adsorbent 14 downward, and
Also, defrosting water from above is prevented from directly falling onto the defrosting heater 13.

The heat insulating material 16 suppresses the heat of the adsorbent 14 from being radiated from the roof member 15 made of metal and having good heat conductivity,
In addition, defrosting water drops on the roof member 15 and the roof member 1
The heat shock of the adsorbent 14 due to the rapid cooling of 5 is prevented.

Thus, the deodorizing adsorbent 14 and the roof member 1
5 and the heat insulating material 16 block linear radiative heat transfer, heat transfer is significantly reduced, and long-time heating is required in the conventional example in order to apply heat to the upper layer of the cooler 6 to melt frost. Met.

However, in the defrosting apparatus of the present invention, the liquid refrigerant 42 that has been isolated in the refrigerant tube as shown in FIG. 4 is heated by the defrosting heater 13 in the lower layer portion 43 of the cooler 6 and evaporated. Move to upper layer 44 (direction of white arrow A) and move to upper layer 4
It will carry heat to 4. In the upper layer portion 44, heat is taken by the melting of the frost 45, and the refrigerant is condensed again into a liquid and flows to the lower layer portion by its own weight (direction of arrow B). By repeating this, efficient heat transfer utilizing evaporation and condensation of the refrigerant is performed inside the cooling pipe, and the frost adhering to the outer surface of the upper layer portion is removed from the inside, so that it can be completed in a short time.

That is, the heat taken into the lower layer portion 43 quickly carries the heat to the upper layer portion 44 according to the heat pipe theory described above (direction of arrow C in FIG. 5).

When the defrosting is completed, the bimetal thermostat 18 provided above the cooler 6 detects the temperature rise and sends a signal to the control device 31 to start the operation of the compressor and the fan.

At the same time as the operation of the compressor 23, the switching valve 3
The second slide valve 33 returns to a predetermined position during operation, and the refrigerant again starts smoothly circulating in the refrigeration cycle system.

As described above, according to this embodiment, the cooler 6
The liquid refrigerant 42 enclosed in the inside is heated by the defrost heater 13 located in the lower part, and the lower layer portion 4 in the cooler 6 tube is heated.
It vaporizes in 3 and moves to the upper layer part 44. In the upper layer portion 44, it is cooled by the frost 45 attached to the outer surface of the cooler 6, the gaseous refrigerant is condensed and becomes a liquid, and it moves to the lower layer portion 43 by its own weight. By repeating this, lower layer 4
Since efficient heat exchange between the upper layer part 44 and the upper layer part 3 is performed inside the cooler 6, the frost 45 attached to the outer surface of the upper layer part 44 of the cooler 6 is also heated by the heat of the defrost heater 13 and melted. , It will be possible to defrost very quickly and efficiently. In particular, by short-circuiting and connecting the refrigerant inlet 27 and the outlet 29 of the cooler 6, the refrigerant pipe becomes a loop and the gas refrigerant and the liquid refrigerant move more smoothly. Also, by integrating the three on-off valves, the number of parts can be reduced and the device can be made compact, and can be easily operated with one operation. Also, the compressor 23
By utilizing the pressure change at the time of operation and at the time of stop, the slide valve 33 can be reliably driven, and the power saving defrosting device can generate a relatively small amount of electricity.

As shown in FIG. 6, the refrigerant inlet 27 of the cooler 6 is opened and closed by the first opening / closing valve 28, and the refrigerant outlet 29 is opened and closed by the second opening / closing valve 29 by separate opening / closing valves. Even in the state, the heat transfer by the refrigerant in the cooler is smoothly performed, but the loop form is more effective because the vapor phase flow can be performed.

Further, as shown in FIG. 7, if the first opening / closing valve 28, the second opening / closing valve 30, and the third opening / closing valve 41 are separately switched, the effect of improving the heat transfer efficiency can be obtained, but the switching valve By using 32 as an integrated open / close valve, the number of parts is reduced and a compact design is possible. In addition, when the individual control is performed individually, the timing of each on-off valve may be slightly deviated, and integration is desirable from the viewpoint of reliability.

As shown in FIG. 8, the drive unit 40 can be moved by a slide valve using an electromagnetic valve. However, it is easier to adjust the switching timing by using the pressure change when the compressor is stopped, and the amount of electricity is reduced. The method utilizing the pressure change of the compressor is preferable because it can be operated reliably without being required.

[0062]

As described above, according to the present invention, the liquid refrigerant contained in the cooler is heated by the defrosting heater located in the lower part, evaporates in the lower layer in the cooler tube and moves to the upper layer. In the upper layer portion, it is cooled by frost adhering to the outer surface of the cooler, the gaseous refrigerant condenses into a liquid, and moves to the lower layer portion by its own weight. By repeating this, efficient heat exchange between the lower layer and the upper layer is performed inside the cooler, so the frost adhering to the outer surface of the upper layer of the cooler is also heated by the heat of the defrost heater and melts. , It will be possible to defrost very quickly and efficiently. In particular, by short-circuiting the refrigerant inlet and outlet of the cooler, the refrigerant pipe becomes a loop and the gas refrigerant and liquid refrigerant move more smoothly, and the number of parts is increased by integrating the three on-off valves. It is small and can be made compact, and can be easily operated with one operation. Further, by utilizing the pressure change when the compressor is operating and when it is stopped, the slide valve can be reliably driven and the power saving defrosting device can generate a relatively small amount of electricity.

[Brief description of drawings]

FIG. 1 is a schematic view of a refrigeration cycle including a defroster for a refrigerator / freezer according to an embodiment of the present invention.

FIG. 2 is a plan cross-sectional view of a switching valve when the apparatus is operating as a compressor.

FIG. 3 is a plan sectional view of a switching valve of the device when the compressor is stopped.

FIG. 4 is a schematic cross-sectional view showing the operation in the cooler tube of the same device.

FIG. 5 is a vertical cross-sectional view showing a state of heat transfer of the device.

FIG. 6 is a schematic view of a defrosting device showing another embodiment of the present invention.

FIG. 7 is a schematic view of a defrosting device showing another embodiment of the present invention.

FIG. 8 is a plan sectional view of another switching valve of the same device.

FIG. 9 is a vertical cross-sectional view of the upper part of the freezer-refrigerator showing a state in which a defroster for a conventional freezer-refrigerator is arranged.

FIG. 10 is an enlarged cross-sectional view of essential parts of a conventional defrost heater.

FIG. 11 is an enlarged front view of essential parts of a conventional defrost heater.

FIG. 12 is an enlarged cross-sectional view showing a conventional air flow state of essential parts.

FIG. 13 is an enlarged vertical cross-sectional view showing a conventional heat transfer state of essential parts.

[Explanation of symbols]

 6 Cooler 13 Defrosting heater 22 Refrigeration cycle 23 Compressor 24 Condenser 25 Expansion valve 26 Suction pipe 27 Refrigerant inlet 28 First opening / closing valve 29 Suction pipe side outlet 30 Second opening / closing valve 32 Switching valve 33 Slide valve 34 Spring Member 35 First bellows 37 Second bellows 40 Drive part 41 Third on-off valve

Claims (4)

[Claims] 1. A refrigeration cycle system in which refrigerant is discharged from a compressor and returned to the compressor via a condenser, an expansion valve, a cooler, and a suction pipe, and a first opening / closing valve and a refrigerant outlet are provided at a refrigerant inlet port to the cooler. A defrost heater having a second on-off valve and a built-in electric resistor is installed in the lower part of the cooler, and when defrosting the cooler, the operation of the compressor is stopped and the defrost heater is energized. A defroster for a refrigerator / freezer, wherein the on-off valve and the second on-off valve are simultaneously closed to defrost the inside of the cooler. 2. A third opening / closing valve for connecting a refrigerant inlet and a refrigerant outlet of the cooler, wherein when the cooler is defrosted, the operation of the compressor is stopped and the defrosting heater is energized and the first opening / closing is performed. The defroster for a refrigerator / freezer according to claim 1, wherein the valve and the second opening / closing valve are simultaneously closed and the third opening / closing valve is opened to defrost the inside of the cooler in an isolated state. 3. The first opening and closing of the expansion valve side opening when the expansion valve and the refrigerant inlet to the cooler and the suction pipe and the refrigerant outlet from the cooler are connected at a predetermined position and slid by a drive mechanism. The valve includes a slide valve and a drive unit that integrally close a suction pipe side opening with a second opening / closing valve and a third opening / closing valve that short-circuits the refrigerant inlet and the refrigerant outlet of the evaporator. The defroster for a refrigerator / freezer according to claim 2, wherein a switching valve is provided in the cooler. 4. A slide valve drive mechanism comprising a first bellows that expands and contracts due to internal pressure on one side of the slide valve, and a spring member on the opposite side of the first bellows, and is built into the first bellows and the discharge side of the compressor. It features a switching valve with a drive mechanism that drives a slide valve by injecting non-condensable gas into the drive unit composed of the second bellows and the connecting pipe and using the pressure change at the time of compressor operation and stop. The defrosting device for a refrigerator-freezer according to claim 3.