JPS5836870Y2 - rotary compressor - Google Patents

Description

[Detailed description of the invention] This invention relates to improvement of injection cooling for rotary compressors.The purpose of this invention is to heat the condensed refrigerant liquid injected into the cylinder of the compressor inside the compressor at a high temperature. The objective is to prevent the cooling effect from decreasing and to obtain a stable injection refrigerant flow.

In general, the inside of a rotary compressor is high temperature, so the condensed refrigerant liquid injected into the cylinder of the compressor used for injection cooling is heated inside the compressor before being injected into the cylinder via the inlet pipe, so it is cooled. Not only was the effectiveness reduced, but bubbles were generated within the introduction pipe, making the flow of the refrigerant unstable.

In order to eliminate the above-mentioned drawbacks, conventional methods have been taken.

(1) Increase the amount of injected refrigerant J-1r4 (2) Increase the degree of supercooling of the injected refrigerant liquid.

However, according to the method (1) above, not only does the increase in the amount of injected refrigerant cause an increase in the compressor input, but also when the compressor temperature is low, the refrigerant is injected into the cylinder at startup, which causes a temperature rise. However, as a result of increasing the amount of refrigerant injected, the temperature rise characteristics further deteriorate, and during low-load cooling operation or frosting operation, the refrigerant returns to the compressor in a wet state, resulting in a decrease in discharge temperature. This reduces the amount of heat received by the injected refrigerant and increases the cooling effect.In addition, as the amount of injected refrigerant increases, the discharge temperature further decreases and becomes wet, causing liquid compression in the cylinder and decreasing lubricating oil viscosity. The risk of poor lubrication has increased, and since the liquid refrigerant returns to the compressor during defrosting operation, the risk of poor liquid compression and lubrication has become even greater.

Furthermore, according to the method (2) above, the degree of supercooling of the injected refrigerant must be increased using an outdoor fan, an outdoor heat exchanger, etc., and the refrigerant circuit becomes long and complicated.

The present invention is intended to overcome these drawbacks, and will be described below with reference to drawings showing embodiments thereof.

A is a compressor, B is a discharge pipe, C is a condenser, D is a capillary tube which is a pressure reducing device, E is an evaporator, F is a suction pipe,
These are communicated via refrigerant pipes to form a well-known cooling circuit.

In the past, a refrigerant bypass pipe G was branched from the middle of a refrigerant pipe that communicated the condenser C and the capillary tube D, and communicated with the introduction pipe 15.

The compressor A has an electric motor section 2 and a compression section 3 inside,
- Surrounded by cylinder 4.

The compression section 3 consists of a cylinder 5 forming an annular compression chamber 8, and a piston γ that is eccentrically mounted on the drive shaft 6 of the electric motor section 2 within the cylinder 5 and rotates along the side wall of the cylinder 5.

In addition, liquid refrigerant guided through the refrigerant bypass pipe G and a discharge port 9 having a discharge valve 10 leading to the discharge pipe B via the electric motor section 2 in the cylinder 4 is injected into the compression chamber 8. It has an opening 12.

Further, as shown in FIG. 2, the introduction pipe 15 of the present invention has a double pipe structure inside the compressor A, and is composed of an injection pipe 16 and an outer pipe 11.

The injection pipe 16 has one end connected to the refrigerant bypass pipe G.
The outer tube 1γ is welded to the housing 4 at one end and to the connecting tube 13 at the other end. The side pipe end of the cylinder 4 is open to the atmosphere.

Therefore, the space created by the injection tube 16 and the outer tube 11 is filled with air.

Note that 1 is oil stored in the lower part of the cylinder 4.

In the above configuration, the refrigerant discharged from the compressor A passes through the discharge pipe B to the condenser C and is liquefied, and the condensed refrigerant liquid is decompressed by the capillary tube D and gasified by the evaporator E, and then passes through the suction pipe F to the condenser C. It is sucked into compressor A.

The refrigerant liquid condensed in the condenser C is injected into the compression chamber 8 of the cylinder 5 through the refrigerant bypass pipe 24, the injection pipe 16 of the introduction pipe 15 of the present invention, the thin pipe 14, and the opening 12. The gas in the compression chamber 8 is cooled by latent heat of vaporization.

Here, the space formed by the injection pipe 16 and the outer pipe 1γ allows the air existing in that space to avoid direct contact with the high-temperature part of the compressor A as in the past, and the outer pipe 1γ and injection tube 16
Since the thermal resistance between the injection tube 16 and
The amount of heat received by the refrigerant is reduced, and the temperature of the refrigerant in the injection pipe 16 is less likely to rise.

As a result, it is now possible to perform cooling with a smaller amount of refrigerant injected than before, which not only reduces the compressor input, but also solves problems that arise due to low compressor temperatures and large amounts of injected refrigerant, that is, the start-up characteristics at startup. This can alleviate the risk of liquid compression and lubrication failure during low-load cooling, frosting, and defrosting operations.

Further, since the amount of heat received by the injected refrigerant in the introduction pipe 15 is reduced, bubbles are no longer generated in the injection pipe 16, and a stable flow of the injected refrigerant can be obtained.

The above effect can be improved by interposing a heat insulating material between the injection pipe 16 and the outer pipe 11 of the introduction pipe 15, since heating of the refrigerant liquid to the introduction pipe 15 can be further reduced.

Furthermore, if the injection tube 16 is subjected to infrared reflection treatment, the influence of radiation from the high temperature outer tube 17 can be prevented, and the cooling effect can be further improved.

As is clear from the above embodiments, the rotary compressor of the present invention cools the cylinder by intermittently injecting the condensed refrigerant liquid into the cylinder during compression, and introduces the condensed refrigerant liquid into the cylinder. An inlet pipe is provided in the compressor, and includes an injection pipe having one end communicating with the opening of the cylinder and the other end serving as the condensed refrigerant liquid inlet, and an injection pipe having one end closed and the other end open to the atmosphere and the atmosphere open end being connected to the cylinder. - of the compressor
It has a double pipe structure with an outer pipe fixed to the cylinder, and a space is provided between the injection pipe and the outer pipe to prevent direct contact between the injection pipe and the high temperature part of the compressor. , with a simple structure, it is possible to prevent heating of the injected refrigerant inside the compressor, and as a result, not only can the cooling effect be prevented from decreasing, but also the amount of injected refrigerant can be reduced, reducing the compressor input, and reducing the This improves the start-up characteristics of the refrigerant, reduces the risk of poor liquid compression and lubrication during low-load cooling operation, frosting operation, and defrosting operation, stabilizes the flow of injected refrigerant, and is easy to manufacture. It produces effects such as:

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of a rotary compressor showing an embodiment of the present invention, and FIG. 2 is a sectional view of an inlet pipe portion of the rotary compressor. A...Compressor, 4...Cylinder, 5...Cylinder, 15...Introduction pipe, 16...Injection pipe, 17...Outer pipe.

Claims (1)

[Scope of utility model registration request] A rotary compressor that intermittently injects condensed refrigerant liquid into a cylinder in the middle of compression for cooling is configured, and an introduction pipe for introducing the condensed refrigerant liquid into the cylinder is connected within the compressor so that one end thereof is connected to the opening of the cylinder. an injection pipe, the other end of which is connected to the condensed refrigerant liquid inlet; and an outer pipe, one end of which is closed, the other end of which is open to the atmosphere, and the end of which is open to the atmosphere is fixed to the cylinder of the compressor. A double pipe structure is used to prevent direct contact between the injection pipe and the high temperature part of the compressor.
A rotary compressor in which a space is provided between the injection pipe and the outer pipe.