JPH01127857A - Air conditioner - Google Patents

Abstract

PURPOSE: To prevent seizure by placing horizontally, providing two rolling pistons, and forming a refrigerant circuit using a speed-variable compressor, an oil separator, a four-way valve, an indoor heat exchanger, a pressure reducer, and an outdoor heat exchanger. CONSTITUTION: Oil discharged from a compressor 1 is separated by an oil separator 2, passes through a capillary tube 7 for returning oil that constitutes a bypass circuit II and a suction pipe 8, and returns to the compressor 1. Passing the bypass circuit II reduces the circulation path of oil as compared with a case where oil circulates a refrigerant circuit I and returns to the compressor 1. Also, oil is separated by the oil separator 2, so that almost no oil flows to the refrigerant circuit I after the oil separator 2 other than the suction pipe 8 from a merge point 9 between the capillary tube 7 for returning oil and the suction pipe 8 to the compressor 1, thus separating oil being discharged from the compressor using the oil separator and returning it to the compressor quickly and hence preventing an oil level in the compressor from decreasing, preventing seizure, and improving the reliability in the compressor.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat pump type air conditioner for indoor cooling and heating, and in particular to a horizontal type compressor having two rolling pistons and a variable rotation speed. The present invention relates to a device having the following features.

Conventional technology A horizontally mounted variable speed compressor with two rolling pistons has small torque fluctuations and low vibrations because the rolling pistons are located symmetrically with respect to the central axis of the shaft. Therefore, the height of the outdoor unit can be reduced.

Problems to be Solved by the Invention However, when this compressor is used to form a refrigerant circuit consisting of a compressor, four-way valve, indoor heat exchanger, pressure reducer, and outdoor heat exchanger as in a normal air conditioner, the following problems occur. There were some problems.

First, since there are two compression mechanisms, the amount of oil discharged is greater than in a compressor with one rolling piston.

Furthermore, the design of the lubrication path for a variable rotation speed type compressor is based on securing the amount of oil lubrication in the low rotation range, where the amount of oil lubrication is small. Oil discharge amount increases rapidly.

For this reason, when the compressor rotation speed is suddenly increased to start up the heating and cooling system quickly at the start of operation, the oil in the compressor is There was a problem that the level decreased, causing poor lubrication and seizure of the compressor.

Secondly, the oil discharged into the refrigerant circuit covers the surface of the heat transfer tubes, reducing heat transfer performance and causing a large pressure loss in the suction path, especially in the high rotation range. There was a problem that performance deteriorated significantly.

Means for Solving the Problems In order to solve these problems, the present invention provides a horizontal compressor with two rolling pistons and variable rotation speed, an oil separator, a four-way valve, and an indoor heating system. A refrigerant circuit is formed by an exchanger, a pressure reducer, and an outdoor heat exchanger.

Effects According to the present invention, the oil discharged from the compressor can be separated by the oil separator and returned to the compressor in a short time due to the above-described configuration, so that the oil level in the compressor does not decrease and seizure is prevented. This can be prevented and the reliability of the compressor can be improved. Furthermore, since oil discharge into the refrigerant circuit can be almost completely prevented, there is no reduction in heat transfer performance or large pressure loss in the suction path, and performance, especially in the high rotation range, can be greatly improved.

EXAMPLE An example of the present invention will be described below with reference to FIGS. 1 and 2.

In Fig. 1, 1 is a horizontal compressor with two rolling pistons and variable rotation speed, 2 is an oil separator, a is a four-way valve, 4 is an indoor heat exchanger, 5 is a pressure reducer, and 6 is an outdoor compressor. It is a heat exchanger, and by sequentially connecting these, the refrigerant circuit I
is formed. Reference numeral 7 designates an oil return capillary tube that forms a bypass circuit (■) for returning the oil recovered by the oil separator 2 into the compressor 1 in a short time. Connected directly to the compressor. Further, A indicates an outdoor unit, and B indicates an indoor unit.

When the air conditioner configured as described above is operated, the oil discharged from the compressor 1 is separated by the oil separator 2, and passes through the oil return capillary tube 7 and the suction pipe 8, which constitute the bypass circuit and the path (2). and return to compressor 1.

By passing through the bypass circuit ■, the oil circulation path can be shortened compared to circulating through the refrigerant circuit I and returning to the compressor 1, so the time it takes for the discharged oil to return to the compressor 1 is shortened. As a result, the oil level of the compressor does not decrease, seizure can be prevented, and the reliability of the compressor can be improved.

In addition, since the oil can be separated by the oil separator 2, the refrigerant circuit ■ after the oil separator 2 other than the suction pipe 8 between the confluence 9 of the oil return capillary tube 7 and the suction pipe 8 to the compressor 1 Almost no oil flows out. Therefore, oil does not cover the inner surfaces of the heat transfer tubes forming the indoor heat exchanger 4 and the outdoor heat exchanger 6, and heat transfer performance can be improved. In addition, pressure loss in the suction path (pressure loss in the refrigerant circuit ■ returning to the compressor 1 via the indoor heat exchanger 4 after the pressure reducer 5 during cooling, and pressure loss in the external heat exchanger after the pressure reducer 5 during heating) The pressure loss (A pressure loss) in the refrigerant circuit I that returns to the compressor 1 via 6 can be significantly reduced.

Due to these effects, the heating and cooling capacity C of the air conditioner without an oil separator is reduced as shown in Figure 3.
The zero heating and cooling capacity of an air conditioner equipped with an oil separator can be significantly improved, especially in the high rotation range where a lot of oil is discharged.

Effects of the Invention As described above, according to the present invention, there is provided a horizontal compressor having two rolling pistons and variable rotation speed, an oil separator,
By forming a refrigerant circuit with a four-way valve, indoor heat exchanger, pressure reducer, and outdoor heat exchanger, the oil discharged from the compressor can be separated by an oil separator and returned to the compressor in a short time. , the oil level in the compressor does not decrease, seizure can be prevented, and the reliability of the compressor can be improved.

In addition, it can almost prevent oil from being discharged into the refrigerant circuit.
Performance, especially in the high rotation range, can be significantly improved without deteriorating heat transfer performance or causing large pressure loss in the suction path.

[Brief explanation of the drawing]

Fig. 1 is a refrigerant circuit configuration diagram of an air conditioner according to an embodiment of the present invention, Fig. 2 is a comparison diagram of the heating and cooling capacity of the same air conditioner and a conventional air conditioner, and Fig. 3 is a diagram showing the compressor rotation speed and It is a relationship diagram of oil discharge amount. 1...Compressor, 2...Oil separator, 3.
...Four-way valve, 4...Indoor heat exchanger, 5.
...Pressure reducer, 6...Outdoor heat exchanger.

Claims (1)

[Claims] A refrigerant circuit is formed by sequentially connecting a horizontal compressor with two rolling pistons and a variable rotation speed, an oil separator, a four-way valve, an indoor heat exchanger, a pressure reducer, and an outdoor heat exchanger in a ring shape. Air conditioner.