JPS63230970A - Compressor - Google Patents

Abstract

PURPOSE:To enhance the volumetric efficiency of a compressor so as to enhance the compression ability thereof by using a plurality of pipes having different lengths as suction pipes connecting between a compressing element and an accumulator arranged on the suction side of the compressing element. CONSTITUTION:There are provided a compression mechanism part 3 in a space in the lower section of the inside of a cylindrical container 1 and a motor part 2 for rotating the compression mechanism part 3 in a space in the upper section of the inside of the cylindrical container 1. An accumulator 10 for preventing liquefied coolant from being sucked into the compressor is arranged on the suction side of the compressing element. Two suction pipes 12, 13 are laid between the accumulator 10 and the suction side of the compressor. The suction pipe 12 has a length by which the volumetric efficiency is enhanced at a low rotational speed. The second suction pipe 13 has a length by which the volumetric efficiency is enhanced at a high rotational speed. Thus, the volumetric efficiency of the compressor may be enhanced over a wide rotational speed range, thereby it is possible to aim at enhancing the gas compression ability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a compressor, and particularly to a compressor suitable for improving volumetric efficiency.

[Conventional technology]

As described in Japanese Utility Model Application Publication Nos. 57-40679 to 40682, conventional devices have a sliding mechanism for both the suction pipe of the compressor and the pipe on the outlet side of the evaporator in order to change the length of the suction pipe. A type that moves U-shaped suction pipes that are fitted together so that they can move freely by a drive device, a type that increases the length of the suction pipe and provides an intermediate boat that opens in the middle of the suction chamber to connect the meson chamber, and a type that connects the meson chamber. Pressure pulsation on the suction side. There are some that attach a delay element approximately equal to the frequency of . However, in these prior art techniques, it was necessary to provide an additional device to generate pulsations within the suction pipe.

[Problem that the invention seeks to solve]

The above conventional technology aims to improve the volumetric efficiency of a constant speed compressor, and improves the volumetric efficiency by utilizing pulsating flow in the suction pipe in the rotation speed range of 3,000 to 3.600 rl) m (7). Therefore, no consideration was given to increasing the volumetric efficiency over a wide range of rotational speeds.

An object of the present invention is to provide a compressor that can improve volumetric efficiency through pulsating flow in a suction pipe over a wide range of rotational speeds including high-speed operating ranges.

Means for Solving Problem C] The above object is to provide an electric element connected to a compression element whose rotational speed is controlled, an accumulator provided on the suction side of the compression element, and a combination of the compression element and the accumulator. This is achieved by forming the suction pipe into a plurality of pipes having different lengths.

[Effect]

Pressure pulsations are generated within the suction pipes of different lengths in the compressor rotation speed range corresponding to each pipe length to improve volumetric efficiency. Therefore, the volumetric efficiency can be improved in a plurality of rotation speed ranges, and even in a rotation speed controlled compressor, the volumetric efficiency can be improved in a wide rotation speed range, and the performance of the compressor can be improved.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure is a longitudinal sectional view of the compressor of the present invention.

In the figure, a cylindrical container 1 with its axis oriented in the direction of gravity and closed at both ends has a compression mechanism 3 in its lower internal space and an electric plate that rotationally drives the compression mechanism 3 in its upper space. A portion 2 is provided, and these are connected via a shaft 5 and housed integrally. Bearings 6.7 provided on both sides of the cylinder 4 of the compression mechanism section 3 support the shaft 5. A roller 8 is rotated by a shaft 5 inside the cylinder 4. Reference numeral 9 denotes a discharge chamber formed by attaching a cover 7a to the bearing 7.

An accumulator 10 is provided on the suction side of the compression element to prevent liquid refrigerant from being sucked into the compressor. A suction pipe 12 is provided between the accumulator 10 and the suction port of the compressor. 11 is a discharge pipe provided in the container 1. 13 is a second suction pipe provided in parallel with the suction pipe 12.

The suction pipe 12 has a length that improves volumetric efficiency in a low rotational speed range. The second suction pipe 13 has a length that improves volumetric efficiency in a high rotational speed range. This suction pipe 12 and the second suction pipe 13 are connected in parallel between the suction side accumulator 10 and the compression element section 3.

Since such a compressor sucks gas intermittently, the suction pipe 1
The pressure within 2 fluctuates periodically. The pulsating effect is caused by suction pipe 1
This is a phenomenon in which the natural frequency of 2 and the suction frequency match and resonate, causing a significant change in pressure inside the pipe and forcing extra gas into the compression chamber.

This results in improved volumetric efficiency of the compressor. The conditions under which this resonance occurs can be expressed as follows. Here, f: natural frequency (H2) of the suction pipe system,
N: Compressor rotational speed (rpm), a: Sound velocity of refrigerant in the pipe (m/S), t: Suction pipe length (m), Vh: Displacement amount of the compressor (m3), A: Passage cross-sectional area of the suction pipe (m=)
, m: A natural number, and m=
1, and if we transform the equation, we get: Given the rotational speed Nl at which the volumetric efficiency is desired to be improved and the passage cross-sectional area A1 of the suction pipe, an appropriate suction pipe length tl is determined as follows. Here, the second suction pipe 13 whose length is A2) and the passage cross-sectional area of the suction pipe (A2) is connected to the suction pipe 12.
If it is arranged in parallel with , then the volumetric efficiency can be improved even at the rotation speed N2. Figure 2 shows the relationship between rotational speed and volumetric efficiency.

According to FIG. 2, the volumetric efficiency can be improved in a wider range of rotation speeds than in the past. Also, the number of suction pipes to be arranged in parallel is not limited to just two (although there may be more than one).

Also, if the effective length of the pipe A2 + "") is multiplied by 32A1 of the right side + leg, then the case where m = 2 for the natural frequency f1 and the case (2) where m = 1 for the oscillating frequency f2 are the same. , the pressure amplitude is further increased at the rotation speed N2 (and the volumetric efficiency can be further improved at the rotation speed N2. Also, yh
If yh (t2+- to -) is twice (mu+hir), the natural frequency fl of the suction pipe system will be twice 12, so □, fl/
At the frequency of 2(2n-11 (n: natural number), the volumetric efficiency at the frequency f2/2 can be improved while suppressing the drop in the volumetric efficiency. In this way, the volumetric efficiency at the frequency f2/2 can be improved.
+Vh/At) (Lz+Vh/A2)
(7) The ratio should be about 2 to 3 times higher.

According to this embodiment, when the rotation speed is around Nl, resonance occurs in the suction pipe 12 having a length of tl, and the pressure fluctuation inside the tube becomes large, improving the volumetric efficiency, and when around the rotation speed N2, the length of t2 is increased. Resonance occurs in the second suction pipe 13, which has a high temperature, and the pressure inside the pipe fluctuates greatly, improving volumetric efficiency.

Therefore, there is an effect that the volumetric efficiency can be improved in a wide range of rotational speeds around the rotational speeds Nl and N2, and the capacity of the compressor can be improved.

〔Effect of the invention〕

According to the present invention, the volumetric efficiency of the compressor can be improved over a wide rotation range, so if the displacement amount is the same as that of the conventional compressor, the gas compression capacity per unit time can be improved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a compressor according to an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between rotation speed and volumetric efficiency. DESCRIPTION OF SYMBOLS 1... Container, 2... Electric plate part, 3... Compression mechanism part, 4... Cylinder, 5... Shaft, 6.7...
Bearing, 7a... Cover, 8... Roller, 9... Discharge chamber, 1o... Accumulator, 11... Discharge pipe, 12... Suction pipe, 13... Second suction pipe. $2 picture mouth private

Claims (1)

[Claims] 1. A compressor comprising a rotation speed controlled electric plate connected to a compression element, an accumulator provided on the suction side of the compression element, and a suction pipe connecting the compression element and the accumulator. A compressor characterized in that a suction pipe is composed of a plurality of pipes of different lengths.