JPH01318771A - Refrigerant compressor - Google Patents

Abstract

PURPOSE:To lessen the amount of lubricant movement when the difference in pressure is built up between respective crank rooms by arranging connecting ports for uniform oil pressure piping in proximity to the standard oil level of each crank room in a refrigerant compressor wherein plural numbers of compressors are operated in parallel. CONSTITUTION:After refrigerant gas compressed by plural numbers of compressors 1a and 1b has been discharged out of an outlet pipe 3, it is sucked in again into the respective compressors 1a and 1b through an inlet pipe 2. At this moment, when the difference in pressure is built up between respective crank rooms 12a and 12b, lubricant 8 is moved to the side of low pressure. However, since each connecting port 6a and 6b of uniform oil pressure piping 7 is positioned at the height of each standard oil level 9a and 9b, the movement of lubricant 8 is only caused by the difference A in oil level between the oil level at the time of the difference in pressure built up and each standard oil level 9a and 9b. Each upper oil level 10a and 10b is therefore equal to the sum of the oil level A and each standard oil level 9a and 9b, and an increase in oil level is little, thereby making it possible to prevent oil hammering phenomenon and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a refrigerant compressor in which a plurality of compressors share a common refrigerant pipe and operate in parallel.

[Conventional technology]

For example, Figure 2 is from Refrigeration and Air Conditioning Handbook (Basic Edition) P578 (
It is a sectional view showing a cooling device using a conventional refrigerant compressor for parallel operation described in the Japanese Refrigeration Association (published by Japan Refrigeration Association), and in the figure, la*1b is a refrigerant compressor, 2 is a suction pipe, 3 is a discharge pipe, 4a and 4b are pressure equalization piping connection ports provided on the gas side of the crank chambers 12a and 12b of the refrigerant compressors 1a and 1b;
6a and 6b are the oil equalizing pipes installed at the bottom of the crank chambers 12a and 12b of the refrigerant compressors 1a and 1b, 7 is the oil equalizing pipe, and 8 is the crank chamber of the refrigerant compressors 1a and 1b. The lubricating oils 12a and 12b are injected, and 9a and 9b are the standard oil levels of the lubricating oil 8. The lubricating oil levels 12a and 12b are in the crank chamber.

Next, the operation will be explained. Refrigerant compressor 1 a e 1
The refrigerant gas compressed in b is discharged through the discharge pipe 3 while containing a small amount of lubricating oil 8 in the gas, and is passed through refrigerant cycle constituent means such as a condenser, an expansion valve, and an evaporator (not shown). After that, the refrigerant compressor 1 is connected again from the suction pipe 2.
Inhaled into a e 1 b. Even if there is a difference in the amount of oil returned to the refrigerant compressors 1a and 1b, the pressure equalization piping 5 and the oil equalization piping 7 will allow the crank chambers 12a and 12 of the refrigerant compressors 1a and 1b to 12b is communicated with each other, so the oil level height is made uniform and kept the same.

[Problem to be solved by the invention]

Since the conventional refrigerant compressor for parallel operation is configured as described above, there is no pressure difference between the two crank chambers when the refrigerant compressors 1a and 1b are started sequentially and when one compressor is operated by number control operation. When this occurs, due to this pressure difference between the crank chambers, lubricating oil 8 corresponding to the pressure difference, indicated by B in the figure, moves to the side where the pressure in the crank chambers is lower. For this reason, an abnormal state such as an oil hammer phenomenon occurs in the refrigerant compressor on the side where the upper oil level is 10a or 10b, and
The refrigerant compressor on the side where the lower oil level is 11a or 11b has a problem in that oil pressure abnormality occurs due to lack of lubricating oil.

This invention was made to solve the above-mentioned problems, and includes pressure equalization and oil equalization functions between both crank chambers of refrigerant compressors for parallel operation, as well as equalizing the pressure between both crank chambers. - The aim is to obtain a refrigerant compressor that requires only a small amount of lubricant to be transferred even in operations where temporal pressure differences occur, and that does not cause oil hammer phenomenon or oil pressure abnormalities due to lack of lubricant. Means for Solving the Problem] The refrigerant compressor according to the present invention is provided with a pressure equalizing pipe connection port on the gas side of the crank chamber, and an oil equalizing pipe connection port is provided near the above-mentioned crank chamber standard oil level height part. be.

[Effect]

In the refrigerant compressor of this invention, the lubricating oil is transferred between the crank chambers through a 9-way oil piping connection port installed near the standard oil level in the crank chamber, so a pressure difference occurs between the crank chambers. [Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1st
In the figure, 1a+1b is a refrigerant compressor, 2 is a suction pipe,
3 is a discharge pipe, 4ae4b is a pressure equalizing pipe connection port provided on the refrigerant gas side above the crank chambers 12a, 12b of the refrigerant compressors 1a and 1b, 5 is a pressure equalizing pipe, and 6a*6b is a refrigerant compressor 1a* 1b crank chambers 12a, 12
Below b, the oil equalizing pipe connection port is installed near the standard oil level 9ae9b on the lubricating oil side, T is the oil equalizing pipe, 8 is injected into the crank chambers 12a, 12b of the refrigerant compressors 1a, 1b. Lubricating oil, 9a *9b is the standard oil level which is the average height that the lubricating oil 8 reaches during normal operation of the refrigerant compressor.

Next, the operation will be explained. The refrigerant gas compressed by the refrigerant compressors 1a and Ib is discharged through the discharge pipe 3 while containing a small amount of lubricating oil 8 in the gas, and the refrigerant gas is discharged from the condenser, expansion valve, evaporator, etc. (not shown). After successively passing through the cycle configuration means, the refrigerant is transferred from the suction pipe 2 to the refrigerant compressor 1a.
, 1b.

Even if there is a difference in the amount of oil returned to the refrigerant compressors 1a and 1b, both crank chambers 12a and 12b will be communicated with each other by the pressure equalization pipe 5 and the oil equalization pipe 7. Because of this, the oil level is equalized and kept the same.

When the refrigerant compressors 1a and 1b are sequentially started and when one side of the compressor is operated by number control operation, both crank chambers 12a
, 12b. This crank chamber 12
Due to the pressure difference between a and 12b, the lubricating oil 8 corresponding to this pressure difference tends to move to the side where the pressure in the crank chamber is lower. However, in the embodiment of the present invention, since the oil equalizing pipe connection ports 6a and 6b are installed at the height of the standard oil level 9ae9b, the oil level height when the differential pressure is generated and the standard oil level 9ae9b are different from each other. The amount of lubricant transferred, which is the difference from the height, is enough as shown by the person in the figure. After this, the standard oil level 9a
*The lubricating oil 8 is not transferred from the oil equalizing pipe connection ports 6a+6b provided at the height 9b, but the gaseous refrigerant is transferred to eliminate the pressure difference. As a result, the upper oil level 10 of the lubricating oil 8 in the crank chamber in the refrigerant compressor according to the embodiment of the present invention is as shown in FIG. Since the lubricating oil level of the refrigerant compressors 1a and 1b does not rise much, the oil hammer phenomenon does not occur. Also, the lower oil level 11a on the high pressure crank chamber side.

11b, as shown in FIG.
In the refrigerant compressors 1a*1b that have reached the refrigerant compressors 1a and 11b, the lubricating oil level can be sufficiently high to ensure the necessary amount, so no oil pressure abnormality will occur due to lack of lubricating oil.

In the above embodiment, a case was explained in which two refrigerant compressors are operated in parallel, but three or more refrigerant compressors may be operated in parallel, and the same effects as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, when a plurality of refrigerant compressors are operated in parallel, the oil equalization function between these compressors is improved, and in the event that a differential pressure occurs between the crank chambers of these compressors, Since the cooling system is also configured to reduce oil level fluctuations, a highly reliable cooling system can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a cooling device using a refrigerant compressor for parallel operation according to an embodiment of the present invention, and FIG. 2 is a sectional view of a cooling device using a conventional refrigerant compressor for parallel operation. 1a and 1b are refrigerant compressors, 4ae4b are pressure equalization pipe connections, 5 is pressure equalization pipes, 6a and 6b are oil equalization pipe connections, γ is oil equalization pipes, 8 is lubricating oil, 9a and 9b are standard oil levels , 12a,
12b is the crank chamber. Note that the symbols in the figures indicate the same or corresponding parts. ! ! Figure 1

Claims (1)

[Claims] In a refrigerant compressor that operates in parallel with multiple refrigerant compressors, a pressure equalizing pipe connection port provided on the crank chamber gas side of the refrigerant compressor and an oil equalizing pipe connection provided near the standard oil level height part of the crank chamber. A refrigerant compressor characterized by having a mouth.