JPS5984056A - Refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is formed by a compressor, a condenser, a pressure reducing device, an evaporator, etc., and the compressor is controlled to start and stop using an internal temperature detection device, etc. In particular, it relates to improvements in refrigeration equipment, such as refrigerators, which perform predetermined cooling.

Conventional structure and its problems Conventionally, in this type of refrigeration system, there is a lot of high-temperature, high-pressure compressed refrigerant in the condenser when the compressor is in operation, and the pressure is reduced when the compressor is in operation. The device acts as a pressure equalizing pipe that balances the pressures of the high and low pressure circuits, and the high temperature and high pressure refrigerant flows into the evaporator, thereby heating the evaporator. Therefore, after restarting the subsequent compressor, it is necessary to cool the evaporator again, including the heating of the evaporator due to the inflow of high-temperature refrigerant, which is known to result in excessive power consumption for cooling. There is. As an improvement measure for the above-mentioned drawbacks, a refrigerant control valve with a tunic valve cap was installed between the condenser [1] and the evaporator inlet, and the flow path was opened when the compressor was operating, and the flow path was closed when the compressor was stopped. It is known to block high temperature, high pressure refrigerant from flowing into the evaporator. However, in this type of improved refrigeration system, the solenoid valve closes at the same time as the compressor stops, and even during the stop, the solenoid valve maintains the entire high-pressure circuit at high pressure and the entire low-pressure circuit at low pressure. The pressure between the front and rear of the compressor element of the machine is uneven. Therefore, in order to start the compressor when restarting, the compressor motor requires an excessive amount of I-lux, and depending on the conditions, for example, if the power supply voltage is poor and the desired motor torque cannot be obtained, it may not be possible to start the compressor. Sometimes it becomes.

OBJECTS OF THE INVENTION In view of the above points, it is an object of the present invention to reduce the pressure difference between high and low pressures at the time of restart, thereby improving restartability of the compressor.

Structure of the Invention The present invention reduces the pressure difference between high and low voltages at the time of restart by providing a delay device that changes the delay time until the solenoid valve closes depending on the person using the high power supply voltage. It is something to do.

DESCRIPTION OF EMBODIMENTS An embodiment in which the present invention is applied to a household refrigerator will be described below with reference to the drawings.

In the figure, 1 is a compressor, 2 is a condenser, 3 is a pressure reducing device (here, a capillary tube), 4 is an evaporator, and 6 is a refrigerant control valve (
(hereinafter referred to as the solenoid valve 5). A solenoid valve 6 is connected between the outlet of the condenser 2 and the inlet of the capillary tube 3. The compressor 1 is also connected to a relay 7 that opens and closes 9 contacts based on a signal from a temperature detection device e that detects the internal temperature of the refrigerator.
There are still 5 solenoid valves, and the control circuit is configured so that the closing operation of the contact is synchronized with the relay 7, and the opening operation is delayed by a time corresponding to the supply power voltage from the time when the relay 7 opens. The relay 8 is connected in series with the relay 8 configured as shown in FIG.

Next, a control circuit for controlling the opening and closing of the relays 7 and 8 will be explained in detail.

6 is the refrigerator internal temperature detection device as described above, and comparator 9. It consists of resistors R1, R2, R3 and a thermistor 1o provided in a part of the refrigerator.

This temperature detection device 6 detects that when the potential at point A, which is determined by resistor R1 and the resistance value RTH that changes depending on the temperature of the thermistor 1o, is higher than the potential at point B, which is determined by resistors R2 and R3, the output of comparator 9 is 1. 11 oII if it is low to '
It works so that it becomes. The output of this comparator 9 is connected to a relay 7 via a driving means (not shown) such as a transistor.
OR circuit 1
is connected to one input of 1. The output of the OR circuit 11 is configured to send a signal for opening and closing the relay 8 via a driving means (not shown) such as a transistor.

A pulse source 12 is configured to generate pulses, and its output is connected to one input of an AND circuit 13, and the other input of the AND circuit 13 is the output of the comparator 9 of the temperature detection device 6. and is connected via an inverter 14. Further, the output of the AND circuit 13 is connected to delay timers 15 and 16. Therefore, the setting time T1 of the timer 15 and the setting time T1 of the timer 16 are selected such that T1<T2. The output of timer 15 is output from AND circuit 7
The AND circuit 17 is connected to one input of the A
ND and is connected to send a set signal to the R-S flip-flop 19. This power supply voltage detection device 18 outputs an output of '°1' when the power supply voltage is higher than the set value v1 (v).
In the following, we will use °0°'. On the other hand, the output of the timer 16 is connected to the R-S flip-flop 20 to send a set signal.

The Q outputs of the R=S flip-flops 19 and 2o are both connected to the other input of the OR circuit 11 via the inverter 21, and the output of the OR circuit 11 sends a signal to open and close the relay 8 as described above. It is connected to the. Also, timers 15 and 16, R-S flip-flop 1
The reset terminals 9 and 20 are connected so that a reset signal is sent from the output of the comparator 9 of the temperature detection device 6.

Next, the operational status of this configuration will be explained.

When the internal temperature of the refrigerator is higher than a predetermined value, the internal temperature detection device 6 detects the resistance value RT of the thermistor 10.
As H becomes smaller and the A potential becomes higher than the B potential, the output of the comparator 9 becomes II 111, which closes the relay 7 through a driving means such as a transistor (not shown), and the compressor 1 is operated. In addition, since the output of the comparator 9 is 1, one input of the OR circuit 11 becomes Mllll and is unrelated to the other input (the output of the OR circuit 11 becomes °°1゛°. Therefore, driving means such as a transistor The relay 8 is also closed at the same time, and the solenoid valve 6 is also energized, opening the refrigerant flow path and cooling the inside of the refrigerator.Afterwards, when the inside of the refrigerator is cooled to a certain temperature, the resistance value RTH of the thermistor 10 increases. Since the potential A becomes lower than the potential B, the output of the comparator 9 becomes °0", which sends a signal to open the contacts of the relay 7, and the compressor 1 is stopped. Meanwhile, the energization to the solenoid valve 5 is controlled. The relay 8 does not open its contacts unless the output signal of the OR circuit 11 becomes ``0'', and the electromagnetic valve 5 continues to be energized. The output signal becomes II oII and compressor 1
At the same time as the inverter 14 stops, the AND circuit j'f! The input to 513 becomes P1°'' and pulse source 1
The second pulse signal causes the timers 16 and 16 to start counting simultaneously. Here, since the set time T1 of the timer 15 and the set time T2 of the timer 16 have a relationship of T1<T2, the count of the timer 15 ends early and the output "°1" is sent to the AND circuit 17, but at this time the supply power supply voltage is Vl(
v) If it is above, the daily output of the power supply voltage detection device is '1°
' and sends a set signal to Tsubu 70 and Tsugu 19.

On the other hand, if the supplied power supply voltage is less than V1 (v), the output of the power supply voltage detection device 18 is ``0'', and the A N D circuit 1
Since the output of 7 becomes '0'', no set signal is sent to the R-S flip-flop 19 even if the set time T1 of the timer 15 is reached.In this case, time passes further and the set time of the timer 16 is reached. When T2 is reached (the marker 16 directly sends a set signal to the 49 R-S flip-flop 2°), either 19 or 20 depending on the supply voltage.
The Q output II 111 is generated by the set signal sent to one of the R-S flip-flops, and the inverter 2
1, the input to the OR circuit 11 becomes '0'', and the other input of the OR circuit 11 sent from the comparator 9 of the temperature detection device 6 also becomes ++oII, so the output of the OR circuit 11 is °o゛'', the series relay 8 is opened and the solenoid valve 6 is closed. That is, if the supply voltage is higher than the set value V1 (v), the solenoid valve 6 is closed.
Select the shorter T1 for the closing delay time of the power supply type 1.
When (2) is lower than the set value V1(v), the longer opening delay time of the solenoid valve 6, T2, is selected, so that the delay time of the solenoid valve 6 can be varied according to the supply voltage.

Next, the pressure transition within the cooling system after the compressor 1 is stopped will be explained using FIG. 3 while comparing it with the conventional example. The solid line shows the system pressure transition of high pressure P1 and low pressure P2 of the conventional refrigeration system, and the broken line shows the system pressure transition of high pressure P1 and low pressure P2 in the embodiment of the present invention when the supply voltage is higher than the preset voltage 1 (v>Vl). It shows the pressure transition in the cooling system with low IJ=P2'. Furthermore, the dashed line indicates the case where the supply power voltage is lower than the preset voltage v1 (V<V
1) shows the pressure profile of the cooling system for the high pressure p 11/ and the low pressure P2' of l); As is clear from the drawing, when the supply voltage after the compressor 1 is stopped remains at a voltage higher than the predetermined value v1 (V>Vl), the solenoid valve 5 continues to be opened for a relatively short time T1. , when the supply voltage is lower than the predetermined value v1 (V<Vl), the time T2 (T1<T
During 2), in order to keep the solenoid valve 6 open, the refrigerant on the high pressure side in the condenser 2 flows into the evaporator 4 on the borrowing pressure side for each time period, thereby lowering the pressure on the high pressure side to a certain extent, On the other hand, the solenoid valve 5 is closed after the pressure on the low pressure side is increased to a certain level. Therefore, the pressure difference between high and low pressures at restart is lower than that of the conventional example (p
l-p2) If the supply voltage ■ is higher than the set voltage v1, (p1/ -P2/) the supply voltage V becomes the set voltage V
If it is lower than 1 (P1''-P2'), the lower the supply voltage, the more the high-low pressure differential will be reduced, and the restartability of the compressor 1 will be guaranteed according to the supply voltage. I can do it.

As is clear from the above explanation, the present invention provides a refrigerant control valve between the condenser and the evaporator, and this refrigerant control valve is opened when the compressor is operating, and when the compressor is stopped, the refrigerant control valve is opened. The circuit is closed by selecting a delay time depending on whether the power supply voltage is higher or lower than a predetermined set voltage. By lowering the pressure and increasing the reduced pressure, it becomes possible to finally reduce the difference between high and low pressures when restarting the compressor compared to conventional methods, making it possible to restart the compressor. It's easy to do.

Also, if the power supply voltage is higher than the predetermined set voltage 71, the delay time will be short (in some cases, even if there is no delay time, the delay time will be short), and if it is lower than 1, the starting torque will be small, so the delay time will be long. High and low voltage Fj: In order to reduce the force difference, an appropriate delay time can be selected according to the supply voltage, and the starting torque is relatively secured.Even in the case of voltage conditions of 71 or higher, the J when taking delay time:
In order to prevent unnecessary high-pressure refrigerant from flowing into the evaporator and unnecessarily impairing cooling efficiency, it is necessary to restart the compressor after the compressor is stopped in order to maintain a reliable pressure condition depending on the supply voltage situation. The opening delay time of the solenoid valve can be automatically selected to the required time, minimizing the effect on cooling efficiency (or having no effect depending on the delay time setting), creating a reliable compressor even under poor voltage conditions. This has the effect of providing restartability.

In the non-embodiment, the delay time can be varied more finely and over a wide range by dividing the supply voltage into several stages and increasing the number of delay time setting timers. Even more efficient control is possible by configuring four timers whose cumulative time varies linearly with changes.

[Brief explanation of the drawing]

FIG. 1 is a frozen cycle diagram showing one embodiment of the present invention, and FIG.
The figure is an electric circuit diagram thereof, and FIG. 3 is a diagram showing the pressure transition inside the refrigeration system after the compressor is stopped in a conventional example and an embodiment of the present invention.

Claims (1)

[Claims] ! E-compressor, comprising: a condenser, a pressure reducing device, an evaporator, a refrigerant control valve interposed between the outlet of the Kl condenser and the inlet of the evaporator, and temperature detection equipment for detecting the temperature inside the refrigerator. the compressor is operated and stopped, the refrigerant control valve is opened during the operation of the compressor, and after the compressor is stopped, there is a delay until the refrigerant control valve is closed according to the supply voltage. Refrigeration equipment equipped with a delay device that changes the time.