JPH0477220B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control method for improving the efficiency of an air conditioner refrigeration cycle.

[Conventional technology]

FIG. 4 is a diagram showing a conventional air conditioner refrigeration cycle aimed at improving efficiency.

In the figure, 1 is a compressor, 2 is a condenser, 3 is a capillary throttle device, 4 is an evaporator, 5 is an accumulator, and 6 is a block that prevents the refrigerant liquid in the condenser 2 and capillary 3 from flowing into the evaporator 4. The solenoid valve is designed to open the circuit when the compressor 1 is operating and close the circuit when the compressor 1 is stopped. 7 is a bypass that connects the discharge port and suction port of the compressor 1; 8 is a solenoid valve that is a valve provided in the bypass 7; the circuit is closed when the compressor 1 is in operation;
The circuit is designed to be open when stopped. 9 is a check valve that prevents the flow of refrigerant from the condenser 2 side to the discharge port of the compressor 1.

In the refrigeration cycle configured in this way,
To explain the operation during cooling when the evaporator 4 is used as a heat exchanger on the heat utilization side, during normal operation, the solenoid valve 6 is open and the solenoid valve 8 is closed. Now, when the indoor temperature falls below the set temperature, the compressor 1 stops operation, closes the solenoid valve 6, confines the high-pressure refrigerant liquid in the condenser 2 between it and the check valve 9, and closes the high-pressure refrigerant liquid in the evaporator 4. In addition, by opening the solenoid valve 8 and equalizing the pressure at the discharge port and suction port of the compressor 1 through the bypass 7, it is possible to reduce the load on the compressor 1 at the time of restart. It's on. Moreover, not only can the return of the refrigerant at the time of starting the compressor 1 be prevented, but also the refrigerant liquid accumulated in the condenser 2 can be removed from the solenoid valve 6 at the same time as the start of the compressor 1.
When the refrigerant opens, the refrigerant flows into the evaporator 4 and evaporation of the refrigerant begins immediately, quickly cooling the room and increasing the efficiency of the refrigeration cycle.

[Problem that the invention seeks to solve]

The conventional refrigeration cycle configured as described above is an effective means of increasing the efficiency of the device, but in recent years, in order to control the refrigeration cycle more precisely, the conventional throttling device using the capillary 3 and the solenoid valve 6 have been used as the throttling device. Electric diaphragms with an integrated full-close function have come into use. However, this electric throttle device with a fully closing function requires several seconds to go from fully open to fully closed, and when the compressor 1 is stopped, the condenser 2 A large amount of high-pressure refrigerant liquid flows into the evaporator 4, weakening the conventional effect, and if the electric throttle device is fully closed before the compressor 1 stops in an attempt to obtain the conventional effect, the high pressure increases. A problem has arisen in that it has an adverse effect on equipment.

This invention was made in order to solve the above-mentioned problems, and it is possible to control the refrigeration cycle using an electric throttling device without impairing the efficiency improvement of the conventional refrigeration cycle. be.

[Means for solving problems]

The control method for a refrigeration cycle device according to the present invention stops the compressor 1 after the throttle device is fully closed when the compressor 1 is about to stop due to a temperature signal, etc., and also controls the blower device on the condenser side. This is what I did.

[Effect]

In the refrigeration cycle according to the present invention, the expansion device is fully closed to store refrigerant liquid in the condenser 2, and the blower device 11 on the condenser side suppresses a rise in high pressure.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Figure 1 is a diagram showing the refrigeration cycle during cooling, and in this figure, 1, 2, 4, 5,
7 to 9 are completely the same as the conventional device described above.
Reference numeral 10 denotes an electric throttle device that is a throttle device driven by a stepping motor or the like provided between the condenser 2 and the evaporator 4, 11 is an air blower for the condenser 2, and 12 is an air blower for the evaporator 4. 13 is a room temperature sensor, 14 is a pressure sensor, 15 is a compressor 1, a solenoid valve 8, an electric throttling device 10, a condenser side blower device 11, an evaporator side blower according to signals from the room temperature sensor 13 and pressure sensor 14, etc. This is a control circuit that controls the device 12.

In the refrigeration cycle control device 15 configured as described above, as shown in the time chart of FIG.
changes from ON to OFF. This temperature control signal 16
Even when it is turned off, the compressor operation signal 17 does not turn off, and first, the opening signal 18 of the electric throttle device becomes in the closing direction, and the opening starts to gradually close. In addition, at this time, the rotation speed command 19 of the blower device 11 on the condenser side is set to the maximum rotation speed to increase the cooling of the condenser 2 and prevent the increase in pressure on the high pressure side due to the closing of the electric throttle device 10. , the opening is fully closed b
At this point, the compressor 1 and condenser blower 11 are stopped, the refrigerant liquid is confined between the check valve 9 and the electric throttle device 10, and heat loss due to refrigerant flowing into the evaporator 4 side is eliminated. , the solenoid valve signal 20 is turned on, and the bypass 7 between the discharge port and the suction port of the compressor 1 is opened to balance low and high pressures, thereby reducing the load on the compressor 1 at the time of restart.

Further, in the above embodiment, the temperature control signal 16 is
After turning OFF, check valve 9 and electric throttle device 1
The pressure sensor 14 provided between the
As _shown in FIG.
It may be controlled by setting the rotation speed to the maximum.

Furthermore, as shown by the broken line in the same figure, even if the electric throttle device 10 is fully closed, the condenser-side blower device 11 is operated until the point d when the pressure 21 in the condenser ₂ becomes less than a certain value P2. In this way, quickly remove the condenser 2.
By lowering the internal pressure 21, the pressure difference between the evaporator 4 and the evaporator 4 is reduced, thereby reducing leakage caused by the pressure difference from the check valve 9 and the electric throttle device 10, thereby further increasing the effect.

〔Effect of the invention〕

As described above, according to the present invention, even if the opening of the throttle device is fully closed during compressor operation, the condenser-side blower device prevents an abnormally high pressure from rising before the stop, and confines the refrigerant liquid in the condenser. Therefore, even in a refrigeration cycle using a throttling device, the refrigeration cycle can be operated with high efficiency in the same way as in the past.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a refrigeration cycle of an air conditioner according to one embodiment of the present invention, FIG. 2 is a time chart diagram showing a control method according to the present invention, and FIG. 3 is a diagram showing another embodiment of the present invention. FIG. 4 is a time chart showing the refrigeration cycle of a conventional air conditioner. 1 is a compressor, 2 is a condenser, 4 is an evaporator, 10 is an electric throttle device, 11 is a condenser side blower device, 14
1 is a pressure sensor, and 15 is a control device. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A throttle device with a fully closing function, a valve that connects a bypass between a discharge port and a suction port of a compressor when the compressor is in operation and opens when the compressor is stopped, and a valve that connects the discharge port and the suction port of the compressor. In a refrigeration cycle that is equipped with a check valve that prevents the flow of refrigerant from the condenser side to the bypass to reduce heat loss due to compressor operation and stop,
When the compressor is stopped, the compressor is prohibited from stopping until the throttle device is fully closed, and a blower device on the condenser side is operated at the maximum rotational speed. 2. A patent claim characterized in that a pressure sensor is provided between the check valve and the throttle device of the refrigeration cycle, and the blower device on the condenser side is operated until the pressure of the refrigerant sealed in the condenser falls to a predetermined value. range 1
A method for controlling a refrigeration cycle as described in Section 1.