JPH094956A - Refrigerator - Google Patents

Abstract

PURPOSE: To prevent generation of particularly liquid compression at the time of starting and to prevent the decrease in the compressing efficiency due to the introduction of vapor refrigerant to a rotary compressor by suppressing the introduction of the liquid refrigerant condensed in an evaporator to the compressor. CONSTITUTION: The refrigerator comprises an auxiliary evaporator 10 provided in a rotary compressor 1, a three-way valve 6 and a distributing tube 8 for coupling the evaporator 10 to and shutting OFF a refrigerating cycle, and a control circuit 7 for controlling the valve 6. The circuit 7 is formed of an atmospheric temperature sensor for determining the control or non-control of the valve 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator provided with an auxiliary evaporator in a rotary compressor.

[0002]

2. Description of the Related Art In recent years, with the increase in capacity of refrigerators, the adoption of small rotary compressors has become the mainstream in order to increase volumetric efficiency.

Conventionally, a refrigerator of this type has been disclosed in Japanese Utility Model Laid-Open No. 2-124.
The one having a refrigeration cycle as disclosed in Japanese Patent No. 474 was common. Hereinafter, the configuration will be described with reference to FIGS. 4 and 5.

FIG. 4 is a block diagram showing the structure of a conventional refrigeration cycle, and FIG. 5 is an electric circuit diagram of the conventional example.

Reference numeral 1 is a rotary compressor, 2 is a condenser, 3 is a capillary tube, 4 is an evaporator, and 5 is a thermostat which detects the temperature of the evaporator 4 and controls the operation of the rotary compressor 1.

The operation of the refrigerating cycle configured as described above will be described below.

First, the high-temperature high-pressure refrigerant gas discharged from the rotary compressor 1 is condensed by the condenser 2,
It becomes a high-pressure liquid refrigerant. Next, the refrigerant is decompressed by the capillary tube 3 and evaporated in the evaporator 4. At this time, the inside of the refrigerator is cooled in order to remove the latent heat of vaporization from the inside of the refrigerator. After that, the refrigerant is returned to the rotary compressor 1 again, and the refrigeration cycle is repeated. On the other hand, the thermostat 5 detects the temperature of the evaporator 4, stops the operation of the compressor when the temperature reaches a predetermined temperature, and restarts the rotary compressor 1 when the evaporator 4 reaches the predetermined temperature to cool the inside of the refrigerator. Let

[0008]

However, in the above-described conventional configuration, when the rotary compressor is stopped, the refrigerant around the evaporator begins to condense in the low temperature evaporator, so that when the rotary compressor starts operating again. There is a problem that the liquid-phase refrigerant in the evaporator flows into the rotary compressor, causing liquid compression and damaging the mechanical section. On the other hand, if an attempt is made to heat the return pipe to the rotary compressor to evaporate the liquid-phase refrigerant, the vapor-phase refrigerant is heated after the liquid-phase refrigerant is evaporated, and the compression efficiency is reduced. Since the phase refrigerant is evaporated in the return pipe, there is a problem that the gas phase refrigerant is heated and the compression efficiency is reduced.

The present invention solves the above problems, and controls the operation of a rotary compressor without causing liquid compression and without reducing the compression efficiency.

[0010]

In order to achieve the above object, the present invention relates to a rotary compressor having an auxiliary evaporator therein, and the auxiliary evaporator is connected to a refrigeration cycle. And a control circuit that controls the three-way valve that shuts off the valve, the three-way valve, and a flow dividing pipe that divides the refrigeration cycle and the auxiliary evaporator.

The invention according to claim 2 relates to the invention according to claim 1, wherein the control circuit for controlling the three-way valve has a control means for connecting the auxiliary evaporator and the refrigeration cycle for a certain period of time immediately after the rotary compressor is activated. It is added.

Further, the invention according to claim 3 is the invention according to claim 1, wherein means for determining whether to control or not control the three-way valve by an outside temperature sensor is added to the invention according to claim 1.

[0013]

With the above-described structure, the present invention evaporates the liquid-phase refrigerant condensed in the evaporator to prevent the liquid compression, and also prevents the vapor-phase refrigerant from being heated and lowering the compression efficiency.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A refrigerator according to an embodiment of the present invention will be described below with reference to the drawings. The same parts as those of the conventional example are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 1 is a refrigeration cycle diagram of a refrigerator according to an embodiment of the present invention, and FIG. 2 is a control circuit diagram of the same embodiment. In the figure, 6 is a three-way valve that is controlled to open and close by a control circuit 7, and a flow dividing pipe 8 is connected to a return pipe 9 of a rotary compressor 1 and an auxiliary evaporator 10 arranged in the rotary compressor 1, and a thermostat 5 Is off and the rotary compressor 1 is stopped, the relay 11a is off.
Both outputs become L level, the transistor 13 is cut off, the relay 11b is cut off, and the three-way valve 6 is de-energized. In this case, in the refrigeration cycle, the path from the evaporator 4 to the return pipe 9 is connected as shown by the broken line, and the path from the evaporator 4 to the auxiliary evaporator 10 is cut off. Next, when the thermostat 5 is turned on and the rotary compressor 1 is activated, the relay 11a is turned on, a rising voltage is generated at the input of the monostable multi 12, and the trigger is generated. The square wave of is output. This square wave output turns on the transistor 13 and turns on the relay 11b to excite the three-way valve 6. In this case, the refrigeration cycle includes the evaporator 4
And the auxiliary evaporator 10 are connected as shown by a solid line, and the evaporator 4 and the return pipe 9 are cut off, so that the liquid-phase refrigerant condensed in the evaporator 4 while the rotary compressor 1 is stopped is After being completely vaporized by the auxiliary evaporator 10 through the three-way valve 6, it returns to the rotary compressor 1 through the flow dividing pipe 8.

Further, the control circuit 7 is provided with a control function for turning off the relay 11b when a preset time has elapsed, setting the output of the monostable multi 12 to L, and cutting off the transistor 13 again to make a three-way valve. 6 is de-energized.
At that time, the auxiliary evaporator is shut off in the refrigeration cycle, and the normal refrigeration cycle operation is resumed.

Furthermore, as shown in FIG. 3, the outside air temperature sensor 14 detects the outside air temperature, and when the temperature is below the set value of the comparator 15, the output of the comparator 15 becomes H, and the monostable multi 12 is detected. The trigger is applied only when the rotary compressor 1 is started by the AND element 16, and the same control as the control circuit 7 is performed.

When the outside air temperature is above the set value of the comparator 15, the output of the comparator 15 becomes L, and the AND element 16
Output is always L, rotary compressor 1
The control circuit 7 does not control the three-way valve and always performs the normal refrigeration cycle operation, because the monostable multi-multi-valve 12 is not triggered regardless of whether it is started or stopped.

In the refrigeration cycle configured as described above, liquid compression is prevented and heating of the vapor phase refrigerant is performed by appropriately controlling the connection and disconnection of the auxiliary evaporator provided in the rotary compressor through the three-way valve. It prevents the compression efficiency from being lowered.

[0020]

As is apparent from the above description, according to the refrigerator of the present invention, the liquid-phase refrigerant condensed in the evaporator of the refrigeration system is evaporated by the auxiliary evaporator provided in the rotary compressor to compress the liquid. The present invention provides a refrigerator in which the vapor phase refrigerant is heated and the compression efficiency of the rotary compressor does not decrease.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram of a refrigerator according to an embodiment of the present invention.

FIG. 2 is a control circuit diagram of a three-way valve of the refrigerator.

[Fig. 3] Control circuit diagram of the three-way valve according to the outside temperature of the refrigerator

FIG. 4 is a refrigeration cycle diagram of a refrigerator in a conventional example.

FIG. 5 is a control circuit diagram of the refrigerator.

[Explanation of symbols]

 1 rotary compressor 6 three-way valve 7 control circuit 8 diversion pipe 10 auxiliary evaporator 14 outside air temperature sensor

Claims (3)

[Claims] 1. A rotary compressor having an auxiliary evaporator therein, a three-way valve for connecting and disconnecting the auxiliary evaporator to a refrigeration cycle, a control circuit for controlling the three-way valve, the refrigeration cycle and the auxiliary evaporation. Refrigerator with a diversion tube that diverts the vessel. 2. The refrigerator according to claim 1, wherein the control circuit for controlling the three-way valve has control means for connecting the auxiliary evaporator to the refrigeration cycle for a certain period of time immediately after the rotary compressor is activated. 3. The refrigerator according to claim 1, wherein the control of the three-way valve and the non-control of the three-way valve are determined by an outside air temperature sensor.