JPS60114659A - Turbo 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 [Technical Field of the Invention] The present invention relates to a device for preventing oil leakage in a turbo refrigeration system.

[Prior art]

An example of a conventional device for preventing oil leakage will be explained with reference to FIG.

In Figure 1, 1 is a centrifugal compressor and 2 is a condenser.

3 is an evaporator, 4 is an expansion valve, and 5 is lubricating oil 5a' for the compressor l.
z Oil tank for supply, 6 is motor room, 7 is gear room, 8 is compression chamber, 9 is pressure equalization chamber, 10 is suction port, 11 is vane, 12 is oil pump, 13 is oil mist and refrigerant 14 is an oil return path that communicates between the gear chamber 7 and the oil tank 5; 15 is a pressure equalization path that communicates between the pressure equalization chamber 9 and the separator 13; 16 is an oil return path that communicates with the oil tank 5; A refrigerant return path for the refrigerant that cools the motor communicates between the motor chamber 6 and the evaporator 3; 17 is a motor cooling refrigerant path that communicates the motor chamber 6 and the condenser 2 and guides liquid refrigerant to the motor chamber 6; 18 is a gear The oil supply path 19 communicates the chamber 7 and the oil pump 12, the suction path 20 communicates the evaporator 3 and the suction port 10, and the discharge path 20 communicates the condenser 2 and the compression chamber 8. The apparatus is constructed, in particular a compressor 1. Condenser 2. Evaporator 3. Expansion valve 4. Suction path 1
9. A refrigeration cycle is constructed by applying the discharge path.

Next, the operation for preventing oil spillage will be explained.

In FIG. 1, the pressures in the pressure equalization chamber 9 and the gear chamber 7, which are the lowest pressures in the refrigeration system, are equalized and the pressures in the motor chamber 6 and compression chamber 8 are also maintained at a low pressure. As a result, the motor chamber 6. Refrigerant gas flows into the gear chamber 7 in the direction of the arrow in FIG. 1 from the shaft that passes through each chamber of the compression chamber 8 and the pressure equalization chamber 9, and is equalized in pressure with the gear chamber 7 through the oil return path 14. The oil flows into the oil tank 5. However, in the oil return path 14, lubricating oil 5a is formed by a liquid reservoir.
The refrigerant gas from the gear chamber 7 mixes and flows, and oil mist is mixed into the oil tank 5, causing an oil leak. Therefore, the mixed oil mist and refrigerant gas are separated by the separator 13, and only the refrigerant gas is supplied to the pressure equalization chamber 9 via the pressure equalization path 15 to prevent oil from rising. Centrifuge 1 as above
Separation by 3 was currently the most effective method.

In the conventional device configured as described above, oil leakage is prevented to some extent during steady operation.

In particular, when a large amount of refrigerant is dissolved in the lubricating oil 5a at startup, the pressure in the oil tank (hereinafter referred to as TP) suddenly increases.
Forming occurs due to a decrease in the pressure, or during operation with the vanes closed (sometimes Also, in the vane opening range A (described later), a large amount of refrigerant gas mixed with oil mist flows through the oil return path 14, and the oil cannot be completely separated by the separator 13, causing the upper oil to be shrunk. There was a drawback that this occurred.

[Summary of the invention]

This invention was made in order to eliminate the above-mentioned drawbacks of the conventional art. A pressure equalization valve is provided in the pressure equalization path and the suction path to adjust the flow rate of refrigerant gas flowing through the pressure equalization path to the evaporation pressure (
The purpose is to adjust the pressure according to the difference between the pressure (LP) and the oil tank pressure (TP) and always divide the pressure.

[Embodiments of the invention]

Hereinafter, an embodiment of the present invention will be explained using figures. Fig. 2 is a configuration diagram in which a pressure equalizing valve is provided in a pressure equalizing passage and a suction passage, and Fig. 3 is a detailed longitudinal sectional view of the pressure equalizing valve. 4 and 5 are longitudinal cross-sectional views showing the operating state of the pressure equalizing valve. In these figures, the same reference numerals as in FIG. 1 indicate the same or corresponding parts, and in FIG. In the main body of the pressure equalization valve, 22 is a plunger that operates using the pressure difference between the left and right sides and the elasticity of the spring, Ru is the evaporation pressure (LP) side spring on the low pressure side, and Sae is the tank internal pressure (TP) side on the oil tank 5 side. 5 is a connection port communicating with the pressure equalization chamber, and 5 is a connection port communicating with the oil tank.
The plunger 3 is moved in accordance with the pressure (TP), and the flow path area from the oil tank connection port to the pressure equalization chamber connection port 5 changes. Figure 6 is the opening degree of the compressor vane (horizontal axis)
It is a curve showing the relationship between the pressure (SP) of the pressure equalization chamber and the differential pressure (LP-8FX vertical axis) between the pressure (SP) and the evaporation pressure (LP). The differential pressure (i, p-5p) changes greatly according to the control of the compressor vanes. Namely.

A state where the differential pressure is large (LP>SP) is called the vane opening degree A band, and is a state where the vane is closed. The state where the differential pressure is normal (LP>SP) is called the vane opening degree B band, and the state where the differential pressure is very small (LpzsP)'e is called the vane opening degree C band. FIG. 7 is a curve showing the relationship between evaporation pressure (LP) and condensation pressure (hereinafter referred to as HP) at startup, where the horizontal axis is time and the vertical axis is pressure. The pressure equalization regulating valve 21 is configured to adjust the pressure difference (LP-TP) between the pressure (TP) applied to the connection port with the oil tank 5 and the pressure (LP) applied to the connection port n with the evaporator 3.
)K, the plunger n moves from side to side to adjust the flow area, ie, the flow rate, from the oil tank connection port 26 to the pressure equalization chamber connection port. The springs 23j24 on both sides of the plunger 22 are incorporated to adjust the position of the plunger n depending on the degree of differential pressure.

Next, the operation of this invention will be explained.

The differential pressure (LP-TP) is large during flow rate control or startup in the vane opening A band when the vane 11 is closed. Therefore, the plunger 22 moves in a direction in which the flow rate from the oil tank 5 to the pressure equalization chamber 9 decreases according to this differential pressure (see FIG.
Figure 5).

The pressure equalization regulating valve 21 operates to close the pressure equalization path 15.

As a result, during flow rate control, the amount of refrigerant gas flowing into the pressure equalization chamber 9 via the pressure equalization path 15 is suppressed, and the oil mist that has flowed in together with the refrigerant gas is completely separated. Also, at startup, the entire device is placed at the pressure of the stopped state, as shown in Figure 7.
The pressure (TP) and evaporation pressure (LP) of the oil tank 5 also drop rapidly, and a large amount of refrigerant dissolves in the oil tank 5, and this pressure drop causes the lubricating oil to form, as shown in Figure 5. The pressure (sp) of the pressure equalization chamber 9 is also the same as that of the oil tank 5.
The pressure equalizing valve 21 operates to keep the pressure (TP) high (TP>5P) and suppress forming. Due to such flow rate control, the pressure (sp) in the pressure equalizing chamber 9 is low even when the pipe opening is in the A band, and the pressure (TP) in the oil tank 5 is lower than the pressure (sp) in the pressure equalizing chamber 9. High evaporation pressure (LP)
An ideal pressure relationship can be obtained that is extremely low (LP>TP>SP). Also, in the vane opening C band, the differential pressure (LP-T
P ) is very small. Therefore, the plunger η springs as shown in FIG.

Depending on the row, the oil tank 5 also moves in a direction in which the flow rate to the pressure equalization chamber 9 increases, and the pressure equalization regulating valve 21 operates to fully open the flow path. And in the vane opening B band, the differential pressure (LP
-TP) is in the normal state, the plunger 22 is in the position shown in FIG. 4, and the pressure equalizing valve 21 operates. In this way, the pressure equalizing valve, which has a simple structure and is inexpensive, can prevent a large amount of oil from spilling out, and can prevent adverse effects on the equipment, such as a decrease in heat transfer coefficient, for example.

In the above embodiment, a plunger set is used as the pressure equalizing valve, but the pressure (TP) applied to the connection port 26 between the oil tank 5 and the pressure equalizing valve 21 does not have to be of this type. and the pressure (LP) applied to the connection port of the evaporator and the pressure equalization regulating valve 21 (LP-TP). It goes without saying that a similar effect can be obtained with a pressure equalizing valve configured to adjust the flow path area, that is, the flow rate.

〔Effect of the invention〕

Since a pressure equalization valve is installed in the pressure equalization path to adjust the flow rate of refrigerant gas flowing through the pressure equalization path according to (LP-TP), the oil mist is completely separated by the separator at all times, preventing oil buildup. This has an excellent effect in that it can be used as a turbo refrigeration system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional turbo refrigeration system, FIG. 2 is a block diagram showing a turbo refrigeration system according to an embodiment of the present invention, FIG. 3 is a detailed vertical sectional view of a pressure equalizing valve, and FIG. Figure, 5th
The figure is a longitudinal cross-sectional view showing the operating state of the pressure equalization regulating valve, Figure 6 is a curve diagram showing the relationship between the differential pressure between the evaporation pressure and the pressure equalization chamber and the vane opening, and Figure 7 is the evaporation pressure at startup. It is a curve diagram showing the relationship between and condensation pressure. 1... Compressor, 3... Evaporator, 5a... Lubricating oil (
liquid reservoir), 7... gear chamber, 9... pressure equalization chamber, 11...
Vane, 15...Pressure equalization path, 21...Pressure equalization regulating valve.In addition, the same reference numerals in the drawings indicate the same or equivalent parts. Agent Masuo Oiwa (2 others) Figure 6 Figure 6 All C ~> Pupils] r-FJ Figure 7 Akira

Claims (1)

[Claims] A passage that communicates between the gear chamber, which forms a reservoir where the lubricating oil that lubricates each part of the compressor collects after lubrication, and the pressure equalization chamber, which has the same pressure as the rear of the vane, which has the lowest pressure in the equipment during operation. 1. A turbo refrigeration system comprising: a pressure equalizing valve for adjusting a flow rate in the passage according to the difference between the evaporation pressure and the pressure in the passage;