JPS60171356A - Controller for oil level in multi-refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Application Field The present invention relates to an improvement of an oil level control device for a multi-refrigeration machine, and particularly relates to an oil level control device for a multi-refrigerator equipped with a plurality of compressors each having a different internal pressure in the crank chamber. This product relates to multi-refrigerators such as subcooler systems, satellite systems, and two-stage compressors.

(B) Prior Art Conventionally, a multi-refrigerator equipped with a plurality of compressors with different internal pressures in the crank chamber was proposed in Japanese Patent Application Laid-Open No. 55-46315, and was configured as a refrigerant circuit as shown in Fig. 1. There is.

To explain below, (1) is the auxiliary compressor on the side where the internal pressure of the crank chamber (1a) is high, and (2) and (3) are the side where the internal pressure is low in the respective crank chambers (2a) and (3a). (4) is the oil separator, (5) is the condenser, (6) is the liquid receiver, (7) is the subcooler, (8) is the main expansion valve, (9) is the evaporator, These are sequentially connected via piping to form a main refrigerant circuit. The refrigerant gas discharged from the auxiliary compressor (1) and the main compressor (21 (3)) is introduced into the oil separator (4) via a common discharge pipe (10). The separated refrigerant gas is condensed in a condenser (5), and then introduced into a liquid receiver (6) and stored as a liquid refrigerant.

This liquid refrigerant then passes through a sub-cooler, where a part of the liquid refrigerant drawn out from the liquid receiver (6) is branched off from the middle by a branch pipe 0υ, and is depressurized by a supplementary expansion valve (I). After the liquid refrigerant is cooled, the liquid refrigerant is passed through the subcooler (inside the refrigerant) opposite to the refrigerant flow of the liquid refrigerant of the main refrigerant circuit.

Thereby, the liquid refrigerant in the main refrigerant circuit is supercooled by a part of the liquid refrigerant branched from the middle. Also,
The liquid refrigerant branched from the middle is evaporated in the subcooler (7) and then led out from the vaginal subcooler to the auxiliary compressor (1).
has been forced to return to On the other hand, the liquid refrigerant in the subcooler (supercooled in the main refrigerant circuit) is introduced into the main expansion valve (8) and the evaporator (9), where it is evaporated and then returned to the main compressor (2++3). has been done.

In the multi-refrigeration system constructed in this manner, the oil level control device thereof is disclosed in Japanese Patent Publication No. 55-21945 and is constructed as shown in FIG. To explain below, auxiliary pressure Fe4 machine (1) and main compression it2+
(3) together with the refrigerant gas and is discharged from the common discharge pipe (1
The oil (131) separated and stored in the oil separator (4) is supplied to the oil tank 05 via an oil return pipe 041.

This is because the pressure inside the oil tank θω is maintained at a low pressure by the pressure equalizing pipe connecting the oil tank and the suction side of the auxiliary compressor (11), and the oil separator (between 4 oil tanks 0ω Oil Q3 with a differential pressure of
) is pumped. The oil (13) stored in this oil tank Q51 is transferred to the oil return pipe (171,
The oil is supplied to the auxiliary compressor (1) and the main compressor (2) (3) through the oil tank (191 (20+). Approximately the same r:Fv as the crank chamber (1a) of the compressor (1)
c setting and the oil tank and each compressor (1
1 + 21 (by providing a head difference between 31, each oil regulator HIG! fυ
The oil level of each compressor (+1(2+(31)) is equalized by supplying oil (13) to the oil regulator and equalizing the oil level of each compressor (+1(2+(31)).

However, the oil level control device of the multi-refrigerator with +1η is set to approximately the same pressure as the internal high-pressure auxiliary compressor (1,+). Therefore, the supply pressure of the oil (13+) applied from the oil tank to the oil requisite 0 (13+) via the oil return pipe (7) tends to become excessively large, and in particular, the oil level regulator (211+) Valve beyond 1 = 'Hk l +-internal iokada's ki)l-
罎Pe Tsubaki 19.1131 Send oil 03) to Heirenku Deaf. This disturbs the oil equalization effect of the oil regulator αl (201) and the internal high pressure auxiliary compressor (201).
1) and the internally low-pressure main compressor (2) and (3), causing various problems such as an increase in the amount of oil discharged from the main compressor (21 (3)). It lacks reliability as an oil level control device.This problem occurs when the internal high-pressure auxiliary compressor (1) is stopped, the oil tank 05) and the main compressor f2) (3)
This is particularly noticeable as the differential pressure between them becomes even larger.

(c) Purpose of the Invention The present invention was made in consideration of the above points, and its purpose is to improve oil for a multi-refrigerator equipped with several compressors with different internal pressures in the crank chamber. The level control device prevents the oil supply pressure applied from the oil tank to the oil regulator, which is supplied to the main compressor with internal low pressure, from becoming excessively high, maintains the oil equalizing effect of the oil regulator well, and The purpose is to improve the reliability of the oil level control device.

2) Structure of the Invention The structure of the present invention is that in a multi-refrigerator equipped with a plurality of compressors with different internal pressures in the crank chamber, an upper limit setting type (oil level An oil regulator with a lower limit setting type (opens the valve when the oil level falls) is installed on the compressor with lower internal pressure. a first oil return pipe that supplies the oil collected by the oil separator installed in the common refrigerant discharge pipe from the oil separator to the compressor on the side with higher internal pressure; a second oil return pipe that supplies the oil from the oil tank to the oil tank via the upper limit setting type oil regulator; This system is equipped with a pressure equalization pipe that passes through the vehicle between the 111N oil tank and the suction side of the internal low-pressure compressor, and the oil separated by the oil separator is first It is returned to the internal high-pressure compressor, and the oil level of the compressor is adjusted appropriately using the upper limit setting type oil regulator installed in this compressor, and the excess oil is temporarily stored in the oil tank. By appropriately supplying oil to the internal low-pressure compressor via a lower limit setting type oil regirator, the pressure in the oil tank is lower than before and prevents excessive oil supply pressure from being applied from the tank to the internal low-pressure compressor. , which maintains the oil equalizing effect of the oil regulator well.

(e) Example An example of the present invention will be explained below based on FIG.
The basic configuration of the refrigerant circuit and the function of the refrigerant circuit are the same as those of the conventional example shown in FIG. I will only explain about.

(l) 9 is an oil regirator of the upper limit setting type (a needle valve is opened when the oil level rises) connected to the auxiliary compressor (11) whose internal pressure is higher in the crank chamber (1a). .θ1 and (2i are the main compressors where the internal pressure of the respective crank chambers (2a) and (3a) is low +2) (3) K connected lower limit setting type (when the oil level falls, the needle valve is opened) Incidentally, it goes without saying that the oil regulator (11t2tll) in the conventional example is a lower limit setting type. This is the first oil return pipe that supplies 1 from the oil separator to the internal high-pressure auxiliary compressor (11). The oil regirator (a second oil return pipe that supplies oil to the oil tank α9 via the lubricant. Here, the oil tank Q5) is provided above the internal low-pressure main compressors (2) and (3). aη is a third oil return pipe that supplies the oil (13i) in the oil tank 115 to the internal low-pressure compressor +21(3) via the lower limit setting type oil regulators 26, respectively. is a pressure equalizing pipe that connects the oil tank U4 and the common refrigerant pipe 4 on the suction side of the internal low pressure main compressor (21(3)).

In the oil level control device configured in this way,
When oil is discharged from the auxiliary compressor (1) and the main compressor (2+(31) together with refrigerant gas, a common discharge pipe (10)
The oil is separated and stored in the oil separator (4) through the oil separator (4). OJ of oil stored in this oil separator is supplied into the crank chamber (1a) of the auxiliary compressor (1) with internal high pressure via the first oil return pipe (141) due to the pressure difference. When there is excess oil Q3i in the auxiliary compressor, the needle valve of the upper limit setting type oil regulator installed in the compressor is opened.Meanwhile, the oil tank (1
The pressure inside the acute chamber is maintained at a lower pressure than before by a pressure equalizing pipe (16). That is, the internal low pressure main compressor (2) (31
The pressure is set to be the same as that of the crank chambers (2a) and (3a). For this reason, the excess oil a is blocked in the auxiliary compressor (1), and due to the pressure difference, the upper limit setting type oil regirator ui
, the oil tank u via the second oil return pipe (2i+)
5! supplied to The oil (131) once stored in this oil tank is connected to the tank and the internal low pressure main compressor (
2) (, 3), the oil is supplied to the lower limit setting type oil regulator (L6 (2()) via the third oil return pipe (1η). At this time, the oil tank α9 Conventionally, the pressure inside the main compressor (
203) will not become excessive. The respective oil regulators (I- are the cranks W, (2a) of the connected main compressors (21<3), respectively.
When the oil (131) in (3a) is insufficient, the needle valve is opened and an appropriate amount of oil (13) is introduced into the main compressor +
21 (3). That is, the oil (1'5) in the oil tank (15) is supplied to the main compressors (2) and (3) in just the right amount by the lower limit setting type oil regulator (19) □□□.

FIG. 3 shows another embodiment, which includes a bypass pipe (23) which is connected to bypass the internal high-pressure auxiliary compressor (1), and an auxiliary compressor (23) provided in this bypass pipe.
1) A solenoid valve (C) that opens only when the system stops.
This is an addition to the embodiment shown in FIG.

This is because the auxiliary compressor (1) stops, the pressure inside the compressor becomes high, the pressure difference between the oil separator (4) and the compressor decreases, and the oil supply from the oil separator (4) becomes insufficient. In this case, by opening the solenoid valve (24J), oil is guided directly from the oil separator (4) to the oil tank Q51, and the main compressor (2) (with internal low pressure) is
3) to facilitate smooth refueling. That is, this is more effective in improving the reliability of the oil level control device.

(f)) Effects of the Invention As described above, the present invention provides an upper limit setting type ( Install an oil regulator with a lower limit setting type (opens when the oil level drops) on the compressor with lower internal pressure, and install an oil regulator with a lower limit setting type (opens when the oil level drops) on the compressor with lower internal pressure. A first oil return pipe that supplies oil recovered by an oil separator installed in a common refrigerant discharge pipe from the oil separator to the compressor on the side with higher internal pressure; A second oil return pipe supplies oil to the oil tank via the upper limit setting type oil regulator, and a second oil return pipe supplies oil from the Kono oil tank to the internal low pressure compressor via the lower limit setting type oil regulator. The system is equipped with an oil return pipe (No. 3) and a pressure equalization pipe that communicates the oil tank with the suction side of the internal low-pressure compressor. Adjust the oil level of the compressor using the upper limit setting type oil regulator attached to this compressor.The excess oil is temporarily stored in the oil tank, and then the lower limit setting type oil regulator is removed from the oil tank. 4f is supplied to the internal low pressure compressor as appropriate through
The school is made up of J7 students. Therefore, the pressure inside the oil tank can be set lower than before, and the oil supply pressure applied from the tank to the oil regulator of the internal low-pressure compressor is prevented from becoming excessive. This maintains good oil equalization effect and improves the reliability of the oil level control system.

[Brief explanation of the drawing]

Fig. 1 is a refrigerant and oil circuit diagram of a multi-refrigeration machine showing a conventional example, Fig. 2 is a refrigerant and oil circuit diagram of a multi-refrigeration machine showing an embodiment of the present invention, and Fig. 3 is another embodiment. It is a circuit diagram of refrigerant and oil of a multi-refrigeration machine showing. (1)...Auxiliary compressor, (2)(3)...Main compressor, (4)...Oil separator, a4)...First oil return pipe, oil return pipe, 0 mark ;... Upper limit setting type oil regulator, (l! Jl Tsuyoshi... Lower limit setting type oil regulator, (2 leaves... Second oil return pipe. Applicant: Sanyo Electric Machinery Co., Ltd. and one other attorney. Patent Shizuo Sano

Claims (2)

[Claims] (1) In a multi-refrigerator equipped with multiple compressors with different internal pressures in the crank chamber, the upper limit setting type (a method that opens the valve when the oil level rises) is installed on the compressor with the higher internal pressure. A lower limit setting type oil regulator (a type in which the valve is opened when the oil level falls) is installed on each compressor on the side with lower internal pressure, and is also installed on the common refrigerant discharge 'Cl path of each of the compressors. The first oil return 1i5N supplies the oil recovered by the oil separator from the oil separator to the compressor on the side with higher internal pressure, and the upper limit setting type A second oil return pipe that supplies oil from the oil tank to the oil tank via the oil regulator, and a third oil return pipe that supplies oil from the oil tank to the internal low-pressure compressor via the lower setting type oil regulator. 1. An oil level control device for a multi-refrigerator, comprising: a pipe; and a pressure equalizing pipe that communicates the oil tank with a suction side of a compressor having an internal low pressure. (2) A bypass pipe is provided that connects the first oil return pipe and the second oil return pipe to bypass the internal high pressure compressor, and a solenoid valve is provided in this bypass pipe, and the solenoid valve is connected to the internal high pressure compressor. The oil level fllJ control device for a multi-refrigerator according to claim 1, characterized in that the device is opened only when the compressor is stopped.