JPS6149585B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air conditioner equipped with a capillary reach tube, in which the capacity of the refrigerant gas or refrigerant liquid is injected into the compressor from the middle of the capillary reach tube can be controlled.

Conventionally, the method of controlling the capacity by performing gas injection or liquid injection into the compressor is that even if injection is performed from the middle of the capillary reach tube, it is a two-phase flow injection of gas-liquid mixture, or it is a gas-liquid separator. This has the disadvantage that it requires the installation of

The present invention has been made in consideration of this, and in an air conditioner, a capillary reach tube is divided into two parts, a front stage and a rear stage, and a U-bend is provided in the middle, and from the outside and inside of the maximum bending angle of the U-bend. Bypass paths are provided in each case, and gas is injected into the compressor via a solenoid valve. Gas is injected from the bypass path connected to the outside of the U-bend, and gas is injected from the bypass path connected to the inside of the U-bend. The liquid is injected.

Hereinafter, details of the present invention will be explained based on illustrated embodiments. Fig. 1 is a diagram showing one embodiment of the system. In the figure, 1 is a compressor, and the refrigerant gas compressed to high temperature and pressure by the compressor 1 flows along the arrow during cooling operation. The refrigerant that exits the compressor 1 passes through the four-way valve 2, flows into the condenser 3, is condensed, and the refrigerant, which has become a high-temperature, high-pressure liquid, passes through the capillary reach tubes 5, 6, becomes low-temperature and low-pressure, and flows into the evaporator 4. A refrigerant circuit is formed in which the refrigerant evaporates, passes through the four-way valve 2, and is sucked into the compressor 1 again. Further, a U-bend 7 was provided in the middle of the two capillary reach tubes 5 and 6, and a liquid injection bypass path 9 was provided which reached the compressor intermediate pressure 10 from the inside 8 via a solenoid valve 12. A represents indoors. During heating operation, the second
The flow is as shown in the diagram: compressor 1, four-way valve 2, condenser 4
The refrigerant that passed through the capillary reach tubes 5, 6,
It is sucked into the compressor 1 again via the evaporator 3 and the four-way valve 2. When the solenoid valve 12' is open,
It branches from the outside 8' of the U-bend 7 and connects the compressor intermediate pressure 1 via a gas injection bypass passage 9'.
It is designed to be indexed to 0.
FIG. 3 shows a gas-liquid two-phase flow flowing through the U-bend, and as shown in the figure, as confirmed through experiments by the inventors, gas flows on the outside and liquid flows on the inside.
Figure 4 shows the amount of liquid injection and COP (or
Figure 5 shows the correlation between the amount of liquid injection and COP (or EER). Moreover, FIG. 6 shows the correlation between the amount of gas injection and heating capacity.

That is, in the air conditioner of the present invention, since the bypass path is branched from the inside of the U-bend portion during cooling operation, the liquid shown in FIG. 3 is injected, and the liquid shown in FIGS. As shown in Figure 3, it is possible to reduce the cooling capacity without lowering the COP too much, and during heating operation, on the other hand, since the bypass path is branched from the outside of the U-bend, gas injection is performed as shown in Figure 3. becomes the 6th
As shown in the figure, ability improvement can be measured.
According to the present invention, during cooling operation, COP
Capacity can be reduced without lowering
It has the advantage of reducing energy loss due to turning on and off the compressor, and also allows capacity to be increased during heating without turning on the heater.

[Brief explanation of the drawing]

1 and 2 are refrigerant circuit diagrams showing an embodiment of the present invention, in which FIG. 1 shows the cooling operation, and FIG. 2 shows the heating operation. Figure 3 is a diagram showing the state of the gas-liquid two-phase flow flowing through the U-bend, Figure 4 is a diagram showing the correlation between the amount of liquid injection and cooling capacity, and Figure 5 is a diagram showing the relationship between the amount of liquid injection and cooling capacity.
The figure shows the correlation between the liquid injection amount and COP, and FIG. 6 shows the correlation between the gas injection amount and heating capacity. In the figure, 1 is a compressor, 2 is a four-way valve, 3 and 4 are heat exchangers, 5 and 6 are capillary reach tubes, and 7 is a U
Bend, 8 and 8' are branch points, 9 is a liquid injection bypass passage, 9' is a gas injection bypass passage, 10 is an injection injection port, 1
2 and 12' indicate solenoid valves.

Claims (1)

[Claims] 1 In an air conditioner that forms a refrigerant circuit in which refrigerant passes through the compressor, condenser, capillary reach tube, and evaporator and returns to the compressor, the capillary reach tube is divided into two parts, the front stage and the rear stage, and the A U-bend is provided in the middle, and a bypass path for gas injection that reaches the compressor medium pressure from the outside of the maximum bending angle of the U-bend via a solenoid valve is connected from the inside of the maximum bending angle of the U-bend via the solenoid valve. An air conditioner characterized in that each bypass passage for liquid injection is provided to reach the intermediate pressure of the compressor.