JPH0230427B2 - REITOKINOSEIGYOSOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a refrigerator.

FIG. 1 shows an example of a refrigerant circuit of a conventional refrigerator with a capacity control mechanism and its control device.

When the power supply 8 is applied to the control device 9, the temperature control device 10 instructs the compressor 1 to operate. The high-temperature, high-pressure refrigerant gas compressed by the compressor 1 radiates heat in the condenser 2, condenses and liquefies, and reaches the expansion device 3. The depressurized refrigerant enters the evaporator 4, absorbs heat from the air flowing through the evaporator 4, evaporates, and returns to the compressor 1 to complete the refrigeration cycle. As a result, the space 13 is cooled, and when the temperature detected by the temperature detector 6 provided in the airflow flowing through the evaporator 4 approaches the set value set by the temperature setting device 14, the temperature control device 10 opens the valve. degree indicator 12
command to open valve 5. The valve opening degree indicating device 12 compares the temperature detected by the temperature detector 6 and the temperature set by the temperature setting device 14, and then determines that the temperature detected by the temperature detector 6 matches the set value. A command is issued to adjust the opening degree of the valve 5 as shown in FIG. As a result, the high-temperature, high-pressure refrigerant that exits the compressor 1 passes through the valve 5, joins with the refrigerant that has passed through the expansion device 3, and enters the evaporator 4 without being cooled. As a result, part of the refrigeration capacity of the refrigerant that has passed through the expansion device 3 is canceled out, and when the opening degree of the valve 5 is appropriate, the heat load in the space 13 and the refrigeration capacity obtained by the evaporator 4 match, This refrigerator can be operated at a refrigerating capacity commensurate with the load. In the case of a refrigerator that uses this capacity control method, when the outside air temperature is low, and as a result, the pressure of the refrigerant exiting the compressor 1 is not so high, and the temperature is also low, the heat load in the space 13 increases. Since the opening degree of the valve 5 is small, the opening degree of the valve 5 becomes extremely large, and even if the opening degree of the valve 5 is adjusted,
Since there is little change in capacity with a slight change in opening,
Temperature stability deteriorates. Therefore, when the opening degree of the valve 5 instructed by the valve opening degree indicating device 12 exceeds a predetermined value, the temperature control device 10 instructs the heater energization instruction device 11 to energize the heater 7 . As a result, the apparent thermal load on the space 13 increases, and the opening degree of the valve 5 is adjusted to a point that is not too large, resulting in good temperature stability.

The above action is shown in a flowchart as shown in Fig. 2.

However, in the above-mentioned refrigerator with a capacity control mechanism, when the outside air temperature becomes low, the heater 7
When the heater 7 is energized, the energization to the heater 7 is not released, and if the heater 7 is used under conditions of use, for example, where the outside air temperature changes significantly, the high outside air may cause the valve 5 to close. Even when the opening degree of the heater 7 becomes sufficiently small and sufficient temperature control can be achieved without energizing the heater 7, the energization to the heater 7 is not stopped, resulting in wasted power, which is uneconomical. It has the problem that it is.

The present invention has been proposed in view of the above points, and an object thereof is to provide a control device for a refrigerator with a capacity control mechanism that does not waste power.

The present invention includes a capacity control mechanism that controls the refrigerating capacity according to the load, and a heater for heating the cooling air; In the control device for a refrigerator, the capacity control range reaches a heater energization release condition during operation with the heater energized, and in this state, The gist of this is a control device for a refrigerator, characterized in that the device is provided with a means for stopping power supply to the heater when the operation continues for a predetermined period of time, and under conditions where the heater does not require operation, the heater Since the system has a function to stop the operation of the system, wasteful energy consumption can be prevented.

The present invention will be explained below based on examples.

In FIG. 3, numerals 1 to 8 and 10 to 14 are the same as the conventional ones, so explanations thereof will be omitted.

In addition to the above, the control device 19 in this embodiment includes a heater energization condition setting device 21 that sets the energization condition to the heater, that is, a condition that a state exceeding a certain valve opening continues for a certain period of time, and a valve opening instruction device 1
A heater energization condition determination device 20 is provided that determines whether the instruction result of step 2 and the duration measured by the timer 22 match the heater energization conditions, and thereby controls the energization of the heater 7. It's becoming like that.

In the above configuration, when the power supply 8 is applied to the control device 19, the compressor 1 starts operating, and the refrigerant flows through the compressor 1, condenser 2, expansion device 3, evaporator 4, and compressor 1, completing the refrigeration cycle. do. Also, space 1
3 has been cooled and the temperature reaches the set temperature set by the temperature setting device 14. Based on the temperature detected by the temperature sensor 6 and the set temperature, the temperature control device 10 controls the valve opening degree through the valve opening indicating device 12. As a result, when the opening degree of valve 5 is appropriate, this refrigerator is operated with a refrigerating capacity commensurate with the load.

When the outside air temperature decreases, the heat load on the space 13 decreases, but the pressure of the refrigerant exiting the compressor 1 is not so high and its temperature is also low, so the opening degree of the valve 5 has to be extremely large. I don't get it. Under this condition of a large opening, a slight adjustment of the opening cannot be expected to change the performance much, and there is a risk that responsiveness will be poor, resulting in control that lacks stability. Therefore, the valve opening degree indicating device 12
The instruction result and the duration measured by the timer 22 match the heater energization condition set in the heater energization condition setting device 21, that is, the condition that the state of exceeding a predetermined valve opening continues for a predetermined period of time. The heater energization condition determination device 20 determines whether or not the conditions are met, and if they match, the heater energization instruction device 11 is instructed to energize the heater 7 . When the outside temperature rises again while the operation is continued under the condition that the heater 7 is energized, the valve opening indicating device 12 instructs the opening of the valve 5 to close. As a result, the instruction result of the valve opening degree indicating device 12 and the duration measured by the timer 22 match the heater energization release condition set in the heater energization condition setting device 21, that is, the predetermined valve opening degree. The heater energization condition determination device 20 determines whether or not the condition that the condition below continues for a predetermined period of time is met, and if the condition is met, the heater energization instruction device 11
In response, a command is given to stop energizing the heater 7 . FIG. 4 is a flowchart showing the above operation.

According to the embodiment described above, the heater 7 has a function of stopping power supply to the heater 7, which is useful under low outside temperature conditions, but under normal or high outside temperature conditions where it is not necessary. Since the heater 7 is not continuously energized, wasteful energy consumption is eliminated, and a highly economical refrigerator can be obtained.

In the above embodiment, a hot gas bypass was shown as an example of the capacity control mechanism, but the capacity adjustment valve may be installed at another location. For example, when a capacity adjustment valve is installed between the evaporator and the compressor, that is, in the suction pipe, the condition for energizing the heater is when the operation continues for a predetermined period of time with the valve opening less than a predetermined value. The condition for canceling the energization to the heater is when operation with a valve opening of a predetermined value or more continues for a predetermined time (which may be instantaneous).

Further, if the capacity adjustment valve is a three-way valve and is provided between the compressor and the condenser, that is, in the discharge pipe, the valve opening is the valve opening to the bypass side.

Furthermore, when the capacity adjustment valve is used as a throttle device, it is the same as when it is provided in the suction pipe.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an example of the conventional system, Fig. 2 is a flow chart diagram explaining its operation, Fig. 3 is a block diagram showing an embodiment of the present invention, and Fig. 4 is a block diagram explaining its operation. It is a flowchart diagram. 1... Compressor, 2... Condenser, 3... Throttle device, 4... Evaporator, 5... Valve, 6... Temperature detector, 7... Heater, 8... Power supply, 10... Temperature Control device, 11... Heater energization instruction device, 12...
Valve opening degree indicating device, 13...Space, 14...Temperature setting device, 19...Control device, 20...Heater energization condition determining device, 21...Heater energization condition setting device,
22...Timer.

Claims (1)

[Claims] 1. A capacity control mechanism that controls the refrigerating capacity according to the load, a heater for heating the cooling air, and a heater that stops energizing the heater when the load is small and the capacity control range by the capacity control mechanism exceeds a predetermined value. In the refrigerator control device, the capacity control range reaches a heater energization release condition during operation with the heater energized, and the operation in this state is continued for a predetermined period of time. A control device for a refrigerator, characterized in that the device comprises means for stopping energization to the heater when the energization continues.