JPS6139584B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides an air conditioner using a capillary tube, in which a valve is provided between the conduit from the condenser outlet side to the evaporator inlet side, and when the compressor is started, the valve is closed for a predetermined period of time. This invention relates to an air conditioner that opens after closing.

Conventionally, in air conditioners using capillary tubes, after the compressor is started, the difference between high and low pressures gradually increases as it moves to a steady state of operation, which means that it takes a long time to reach steady state of operation. As a result, it takes time for the capacity to reach a steady value, resulting in inefficient operation. Therefore, since it takes time for the room temperature to reach a predetermined temperature, comfort is impaired.

This invention was developed in view of the above-mentioned drawbacks. When the compressor is started, the refrigerant circuit is closed for a short time using a valve, and then opened, thereby obtaining a high-low pressure difference close to that of steady operation in a short time, and as a result, a steady state is achieved. To provide an air conditioner that has high performance, can be operated efficiently, can quickly bring the room temperature to a predetermined temperature, increases comfort, and can also be expected to save energy.

Embodiments of the air conditioner of the present invention will be described below based on the drawings. Fig. 1 is a diagram showing the configuration of one embodiment of the present invention, and 1 in the figure is a compressor, and the refrigerant gas compressed to high temperature and high pressure by this compressor 1 is designed to flow along the arrow. The refrigerant that flows into the condenser 2, condenses and becomes a high-temperature, high-pressure liquid, further passes through the solenoid valve 3, becomes low-temperature and low-pressure in the capillary tube 7, flows into the evaporator 4, evaporates, and the evaporated refrigerant gas returns to the compressor 1. It forms a refrigerant circuit that returns to the 5 is a fan for the condenser 2, and 6 is a fan for the evaporator 4. The electromagnetic valve 3 is provided with a relay in the motor circuit of the compressor 1, and is operated by the drive of the motor, so that it closes when the compressor 1 is started, and is then controlled to open after a predetermined short time has elapsed by a timer. ing. That is, in the air conditioner of the present invention, the solenoid valve 3 is provided midway between the condenser 2 and the capillary tube 7, and is closed for a short time when the compressor 1 is started. Since it does not flow into the capillary tube 7 and the evaporator 4, it accumulates between the inlet side of the solenoid valve 3 and the discharge side of the compressor 1, and the pressure rises rapidly. On the other hand, since refrigerant does not flow from the outlet side of the solenoid valve 3 to the suction side of the compressor 1, the pressure will drop rapidly due to the drawing of the compressor 1, and both the high pressure side and the low pressure side will be stabilized in a short time. The pressure is close to normal pressure. Since the solenoid valve 3 is designed to open a little later than when the compressor 1 is started, steady air conditioning is immediately achieved by opening the solenoid valve 3.

When this invention was applied to an air conditioner with a capacity of 2200 Kca/h and tested, good results were obtained when the solenoid valve 3 was closed for about 25 seconds from the start of the compressor 1. Ta. If the circuit remains closed for too long, the suction side of the compressor 1 will become negative pressure, which will suck in air from small leaks in the refrigerant circuit connections, causing failure of the refrigerant circuit including the compressor 1. Moreover, if the closed circuit time is too short, the predetermined pressure difference will not be obtained.

Figure 2 shows the temporal changes in the discharge pressure Ph of the compressor 1 as well as the suction pressure P of the compressor 1 from the start of the compressor 1 to steady operation when the present invention is implemented in the above-mentioned 2000 Kca/h air conditioner. It is a figure showing a change. Note that the broken line indicates the characteristics of the conventional air conditioner. As is clear from this figure, the air conditioner according to the present invention reaches steady state in about half the time required from the start of the compressor of the conventional air conditioner to reach steady state.

Furthermore, in a normal air conditioner, the pressure difference in the refrigerant circuit changes depending on the outside temperature. That is, the pressure difference is large when the outside air temperature is high, and becomes small when the outside air temperature is low. Therefore, even in the present invention in which a pressure difference is provided by the solenoid valve 3, it is desirable to change the pressure difference depending on the outside temperature. For this reason, although not shown in the drawings, the outside air temperature is also detected in the above embodiment, and the operating time of the timer that controls the closed time of the solenoid valve 3 is changed in accordance with the outside air temperature. .

In the above embodiment, the solenoid valve 3 is closed by detecting the start of the compressor 1. However, the signal for closing the solenoid valve 3 detects the room temperature and turns the compressor 1 on and off. It may also be based on the on signal of the detector.

Furthermore, in the above embodiment, the valve that closes the refrigerant circuit is an electromagnetic valve, but the same effect can be obtained by providing a valve that opens and closes depending on a predetermined pressure difference. There is no need to control the time during which the circuit is opened, and the pressure difference required to open the circuit can be set to a predetermined value.

Furthermore, in the above embodiment, the valve for closing and opening the refrigerant circuit is provided between the outlet side of the condenser 2 and the capillary tube 7, but the same effect can be obtained even if it is provided on the inlet side of the capillary tube 7 and the evaporator (4). can get.

As explained above, according to the present invention, a pressure difference occurs between the condenser outlet side and the evaporator inlet side for a predetermined short period of time from the start of the compressor, that is, during steady operation between the high pressure side and the low pressure side. Equipped with a valve that closes the refrigerant circuit for hours, it quickly achieves steady operation.
This has the effect of allowing efficient operation and reaching a predetermined room temperature faster.

[Brief explanation of the drawing]

FIG. 1 is a refrigerant circuit diagram showing an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing changes over time in the suction and discharge pressures of the compressor from the start of the compressor to normal operation. In the figure, 1 is a compressor, 2 is a condenser, 3 is a solenoid valve, 4 is an evaporator, 5 and 6 are fans, and 7 is a capillary tube.

Claims (1)

[Scope of Claims] 1. In an air conditioner forming a refrigerant circuit in which refrigerant returns to the compressor through a compressor, a condenser, a capillary tube, and an evaporator, a pipe from the condenser outlet side to the evaporator inlet side. An air conditioner characterized in that a valve is provided between the circuits, and the valve is closed when the compressor is started, for a period of time during which a pressure difference occurs between the high pressure side and the low pressure side of the refrigerant circuit during steady operation, and then opens the circuit. 2. In an air conditioner that forms a refrigerant circuit in which refrigerant returns to the compressor through a compressor, a condenser, a capillary tube, and an evaporator, there is a refrigerant circuit between the conduit from the condenser outlet side to the evaporator inlet side. An air conditioner comprising a differential pressure valve that opens when the pressure difference between a high pressure side and a low pressure side becomes the pressure difference during steady operation, and closes when the pressure difference is smaller than this pressure difference.