JPH0518642A - Cooling device - Google Patents

Abstract

PURPOSE:To perform defrosting in a short time and to decrease the increase of temperature in a cooling chamber, such as the interior of a chamber, by a method wherein; during defrosting, a vaporizer is heated and a compressor is stopped, and through release of a bypass solenoid valve, a high temperature gas refrigerant or liquid refrigerant is caused to flow to a vaporizer. CONSTITUTION:When a defrosting amount attains a given value during continuance of cooling operation, a heater 16 for defrosting is energized. A quantity of heat generated by the heater 16 for defrosting is spent for melting of frost produced at first and second vaporizers 11 and 12. Simultaneously with energization of a heater 16 for defrosting, a compressor 21 is stopped. A liquid solenoid valve 23 is closed and a bypass solenoid valve 27 is released. A high temperature gas refrigerant flows through a pipe 29 on the outlet side of the vaporizer 25 to first and second vaporizers 11 and 12 kept at a low temperature to heat cooling pipes 11c and 12c from the inner side. This constitution shortens a defrosting time and eminently shortens a defrosting especially when an open air temperature is high, since a gas refrigerant discharged from the compressor 21 has a high temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a cooling device used in a refrigerator or the like.

[0002]

2. Description of the Related Art FIGS. 6 and 7 are a perspective view showing an evaporator of a conventional cooling device and a side view showing a state in which the conventional cooling device is installed in a refrigerator.
1 is an evaporator composed of a plurality of plate fins 2 and a cooling pipe 3 penetrating the plurality of plate fins 2,
4 is a heating device including a defrosting heater attached to the side surfaces of a plurality of plate fins 2, 5 is a casing having an air suction port 6 at one end and an air outlet 7 at the other end,
It is fixed to the inner wall of the refrigerator 9 and has an evaporator 1 on the air inlet 6 side.
However, a blower 8 is disposed on the air outlet 7 side. 1
0 is a defrosting timer.

Next, the operation will be described. During cooling operation,
The blower 8 is driven and the air in the refrigerator is sucked through the air suction port 6. In the evaporator 1, this sucked-in air is cooled by heat exchange with the liquid refrigerant supplied from the condenser (not shown) to the evaporator 1 via the expansion device (not shown), and the air is blown out. It is blown from 7 into the refrigerator, and the inside is cooled. When this cooling operation is performed for a certain period of time and frost forms on the plate fins 2 of the evaporator 1, the defrosting timer 10 operates and the heating device 4 is energized. At this time, the heat generated from the heating device 4 is conducted to the plate fin 2 and the cooling pipe 3 of the evaporator 1 to start defrosting. When the frost melts, a thermostat (not shown) that detects the temperature of the evaporator 1 operates, the power supply to the heating device 4 is stopped, and the defrosting ends.

[0004]

Since the conventional cooling device is constructed so as to defrost by heat conduction from the heat generating device, it takes a long time for defrosting, the internal temperature rises, and the temperature of the stored items rises. There was a problem that was rising.

The present invention has been made in order to solve the above problems, and can defrost in a short time,
It is an object of the present invention to obtain a cooling device in which the temperature inside the cooling space such as the inside of the defrosting room does not rise.

[0006]

A cooling device according to the present invention comprises a compressor, a condenser, a pressure reducing device, and an evaporator, which are sequentially connected to each other. A bypass circuit for defrosting connected to the outlet side pipe or the inlet side pipe of the evaporator via a bypass solenoid valve, and a heating device for heating the evaporator are provided, and at the time of defrosting, the heating device is operated and the compression is performed. The machine is stopped and the bypass solenoid valve is opened. Also, a compressor, a condenser,
A decompression device, a liquid solenoid valve and an evaporator are connected in sequence, and the outlet side pipe of the condenser of the refrigeration cycle is connected to the inlet side pipe or the outlet side pipe of the evaporator via a bypass solenoid valve. A bypass circuit for frost and a heating device for heating the evaporator are provided, and when defrosting, the heating device is operated, the compressor is stopped, the liquid solenoid valve is closed, and the bypass solenoid valve is opened. It was done like this.

[0007]

In the defrosting operation of the cooling device according to the present invention, the evaporator is heated by the heating device and heated from the inside by the high temperature gas or liquid refrigerant to defrost in a short time.

[0008]

【Example】

Example 1. A refrigerant circuit diagram and a sectional view of a cooling device according to an embodiment of the present invention shown in FIGS. 1 and 2 will be described below. In these figures, 21 is a compressor, 2
Reference numeral 2 is a condenser, 23 is a liquid solenoid valve, 24 is a decompression device, and 25 is an evaporator. A refrigeration cycle is configured by sequentially connecting these with refrigerant pipes. Reference numeral 26 denotes a defrosting bypass circuit in which the discharge side pipe 28 of the compressor 21 is connected to the outlet side pipe 29 of the evaporator 25 via a bypass solenoid valve 27.
As shown in FIG. 2, the evaporator 25 is composed of first and second evaporators 11 and 12 arranged with a predetermined gap, and the first evaporator 11 is a pair of side plates 11a and 11b. A cooling pipe 11c supported at both ends and through which a refrigerant flows, and a plurality of fins 11d fixed to the cooling pipe 11c,
The second evaporator 12 has a cooling pipe 12c whose both ends are supported by both side plates 12a and 12b and through which a refrigerant flows, and the cooling pipe 1c.
2c and a plurality of fins 12d fixed to each other. 13, 14 are the first and second evaporators 11, 1
Spacers that form a gap 15 between the two side plates 11a,
It is arranged so as to be connected between 12a and 11b, 12b. Reference numeral 16 denotes a heating device including a defrosting heater, both ends of which are supported by the spacers 13 and 14, and arranged in the gap 15 between the first and second evaporators 11 and 12. Reference numeral 17 denotes a case to be installed in a refrigerator or the like, which has a bell mouth portion 17a for sucking air and an air outlet portion 17b for blowing out air. The bell mouth portion 17a is provided with a blower 18 Is a first gap with a predetermined gap 15 in the direction crossing the flow of the air discharged from the arrow A direction to the B direction.
And the second evaporators 11 and 12 are provided. The compressor 21 and the condenser 22 are arranged in an outdoor case (not shown).

Next, the operation will be described. First, the air introduced by the blower 18 from the bell mouth portion 17a in the direction of arrow A is cooled by the second evaporator 12, and a large amount of frost is formed on the second evaporator 12. The dehumidified air is further cooled by the first evaporator 11 and discharged in the direction of arrow B. At this time, a small amount of frost is formed on the first evaporator 11. When a predetermined amount of frost is reached while continuing the cooling operation in this way, a defrosting device (not shown) operates and the defrosting heater 16 is energized. Since the defrosting heater 16 is not directly exposed to the inflow side and the outflow side of air,
The amount of heat generated by the defrosting heater 16 does not directly heat the air in the refrigerator,
Expended to thaw the frost formed in 2. At the same time that the defrosting heater 16 is energized, the compressor 21 is stopped by the defrosting control device (not shown), the liquid solenoid valve 23 is closed, and the bypass solenoid valve 27 is opened to prevent the high temperature. The gas refrigerant moves through the outlet side pipe 29 of the evaporator 25 to the first and second evaporators 11 and 12 kept at a low temperature to heat the cooling pipes 11c and 12c from the inside. Therefore, as shown in the defrosting characteristic curve a of FIG. 4, the defrosting time is shorter than that of the conventional defrosting characteristic curve b, and the gas refrigerant discharged from the compressor 21 is particularly high when the outside air temperature is high. Since the temperature is high, the defrosting time is shortened significantly. Note that FIG. 4 compares the same frosting amount, but in reality, the higher the outside air temperature, the more the frosting amount on the evaporators 11 and 12, and thus the practical effect can be obtained. . When the defrosting is completed, the defrosting controller 16 (not shown) stops the energization of the defrosting heater 16 and the bypass solenoid valve 2
7 is closed, the liquid solenoid valve 23 is opened, and the compressor 21 is operated to return to the cooling operation.

In the above embodiment, the discharge side pipe 28 of the compressor 21 is connected to the outlet side pipe 29 of the evaporator 25 by the bypass solenoid valve 2.
Although the defrosting bypass circuit 26 connected through 7 is provided, the invention is not limited to this, and the outlet side pipe 28 of the compressor 21 is connected to the inlet side pipe 30 of the evaporator 25 via a bypass solenoid valve. You may connect, and the same effect as the above is acquired. Further, in the above embodiment, the bypass solenoid valve 27 during defrosting
However, the high temperature gas that has moved to the evaporator 25 is condensed by the evaporator 25, and when the compressor 21 is started after defrosting, the liquid is slightly backed, so that the liquid back is reduced on the device. If necessary, the bypass solenoid valve 27 may be opened for a predetermined time after the start of defrosting.

Embodiment 2. FIG. 5 is a refrigerant circuit diagram of a cooling device according to another embodiment of the present invention. The difference from FIG. 1 is that the outlet side pipe 31 of the condenser 22 is connected to the inlet side pipe 30 of the evaporator 25 and the bypass solenoid valve 33 is provided. The defrosting bypass circuit 32 connected via the defrosting device is provided, and the defrosting control device is controlled in the same manner during defrosting. Since the operation is the same as described above, its description is omitted.

Although the outlet side pipe 31 of the condenser 22 is connected to the inlet side pipe 30 of the evaporator 25 through the bypass solenoid valve 33 in the second embodiment, the invention is not limited to this.
The outlet side pipe 31 of No. 2 may be connected to the outlet side pipe 29 of the evaporator 25 via a bypass solenoid valve, and the same effect can be obtained. Further, in the above-described embodiment, the bypass solenoid valve 33 is opened during defrosting, but since the high temperature liquid refrigerant flows into the evaporator 25 by this, when the compressor 21 is started after defrosting, a slight liquid back-up occurs. Therefore, when the liquid bag needs to be reduced on the device, the bypass solenoid valve 33 may be opened for a predetermined time after the start of defrosting.

In the above embodiment, the evaporator 25 is replaced by the first and second evaporators 1 as shown in FIG.
1 and 12 and the defrosting heater 16 provided in the gap 15 between the first and second evaporators 11 and 12 has been described, but the present invention is not limited to this, and is similar to the conventional one shown in FIG. 6, for example. The defrost heater 4 may be provided on the side surface of the evaporator 1.

[0014]

As described above, according to the present invention, at the time of defrosting, the evaporator is heated by the heating device and the compressor is stopped.
Since the bypass solenoid valve is opened and the high-temperature gas refrigerant or liquid refrigerant is made to flow to the evaporator, it is defrosted in a short time, and the temperature rise of the cooling space such as the inside of the refrigerator during defrosting is reduced. Has the effect of.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram of a cooling device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a cooling device according to an embodiment of the present invention.

FIG. 3 is a plan view showing a detailed structure of the evaporator shown in FIG.

FIG. 4 is a diagram showing a relationship between a defrosting time and an outside air temperature.

FIG. 5 is a refrigerant circuit diagram of a cooling device according to another embodiment of the present invention.

FIG. 6 is a perspective view of an evaporator of a conventional cooling device.

FIG. 7 is a side view showing a state in which a conventional cooling device is installed in a refrigerator.

[Explanation of symbols]

21 compressor 22 condenser 23 liquid solenoid valve 24 Pressure reducing device 25 evaporator 26 Bypass circuit for defrosting 27 Bypass solenoid valve 29 Outlet side tube 30 Inlet tube

Claims (2)

[Claims] 1. A refrigeration cycle in which a compressor, a condenser, a pressure reducing device, and an evaporator are sequentially connected, a heating device for heating the evaporator, and a discharge side pipe of the compressor for the evaporation side pipe. With a defrosting bypass circuit connected to the outlet side pipe or the inlet side pipe of the vessel via a bypass solenoid valve, at the time of defrosting, the heating device is operated and the compressor is stopped to operate the bypass solenoid valve. A cooling device characterized by being opened. 2. A refrigeration cycle in which a compressor, a condenser, a decompression device, a liquid solenoid valve and an evaporator are sequentially connected, a heating device for heating the evaporator, and an outlet side of the condenser. A defrosting bypass circuit in which a pipe is connected to an inlet side pipe or an outlet side pipe of the evaporator via a bypass solenoid valve, and during defrosting, the heating device is operated and the compressor is stopped, A cooling device characterized in that the electromagnetic valve is closed and the bypass electromagnetic valve is opened.