JPS62101808A - Device for regulating bearing lubrication pressure - Google Patents

Abstract

PURPOSE:To prevent rise in hydraulic pressure at the outlet of a pressure regulating valve and normalize the pressure of lubricating oil by moving a pilot valve for controlling the hydraulic pressure from the inlet side to the outlet side of said pressure regulating valve, when shifting from the start of a pump to a normal operation. CONSTITUTION:A port 32 from a pressure regulating device E is provided in a secondary pressure regulating valve 8. At the time of starting, the pressure regulating device E introduces a hydraulic pressure which is not reduced, into a piping 26 from a piping 7 and leads it into a piping 27 through an orifice 29 and a safety valve 30, to feed oil into the bottom port D of a pilot housing 20, an accumulator 31, and a pilot valve port A. Then, the oil flows to a port B, moving the pressure regulating valve 8 in the closing direction. On the other hand, when hydraulic pressure rises at the time of starting a pump, the valve body of a pilot valve rises against a spring 23 due to hydraulic pressure from the port D, causing oil to flow to a port G and the port B, to control the secondary side hydraulic pressure of the pressure regulating valve 8.

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention controls the oil pressure of a lubricating oil system of a bearing in a turbine lubricating oil equipment, and maintains the lubricating oil at normal oil pressure even when the pump is started. This is a device for supplying

[Background of the invention]

Conventionally, the bearing supply pressure of turbine lubricating oil was controlled only by the hydraulic pressure on the outlet side (secondary pressure) of the pressure regulating valve. Due to the characteristics of the regulating valve, when the hydraulic pump is started, it follows the rise in pressure. The valve could not be closed, and the bearing oil supply pressure increased more than necessary.

This resulted in a negative impact on the refueling system. In addition, related devices of this type include, for example, Utility Model Application No. 59-
There is No. 84202.

[Purpose of the invention]

The purpose of the present invention is to prevent the oil pressure from rising at the outlet of the pressure adjustment valve that occurs when the main oil pump starts up, and to normalize the oil pressure supplied to each bearing of the turbine. The aim is to prevent accidents caused by malfunction of the instruments used.

[Summary of the invention]

In the past, in turbine power generation plants, we focused on a problem in which fluctuations in the oil pressure supplied to lubricating oil to the bearings caused abnormalities in the bearing oil pressure, which caused instrument-related malfunctions and had a negative impact on the bearings.

The abnormality in the bearing oil supply pressure was caused by the structure of the bearing oil supply pressure regulating valve, and we decided to optimize it by improving the mechanism.

The pressure regulating valve described above has a mechanism that senses the pressure on the valve outlet side and closes the valve, but the present invention temporarily changes the pressure on the valve inlet side at the time of startup, which causes pressure fluctuations. This is an adjustment device that controls the valve by the pressure on the valve outlet side when normal operation begins.

[Embodiments of the invention]

The present invention will be described in detail.

FIG. 2 shows a basic schematic diagram of the lubricating oil supply system.

The main oil pump 1 or 2 is operated (started), the oil is passed through the bearing oil supply pipe 4, the oil pressure is reduced to approximately 5K by the second pressure regulating valve 5, and then the oil is passed through the oil cooler 6 to the pipe 7. enters the secondary pressure regulating valve 8, reduces the pressure to approximately 1.2K, and connects the pipe 1o.
lubricating oil is supplied between the rotor 13 of the turbine 16 and the bearing 15, and the bearing waste oil is passed from the bearing box 14 to the oil drain pipe 1.
7 and return to oil tank 9. In addition, an emergency oil pump 3 is connected to the piping 4 at the outlet side of the primary pressure regulating valve 5, and both the main oil pumps 1 and 2 are configured to start in order to supply bearing oil in the event of a failure. It has become.

One main oil pump is installed for the backup amplifier.

In the lubricating oil supply system, the pressure of the lubricating oil is reduced in two stages by pressure regulating valves 5 and 8 from the main oil pump outlet. However, when adjusting the pressure, the starting pressure increases abnormally due to a structural problem with the pressure regulating valve. This results in
Adversely affects bearings and instruments. The purpose is to eliminate negative effects.

The structure of the pressure regulating valve is shown in Figure 3.

Regarding the pressure regulating valve 8, adjusting the oil flow and outlet pressure,
Explain the mechanism.

When the pressure of the oil flowing into the inlet boat 16' is low, the pressure of the oil entering the outlet boat 17' is low, so the pressure of the oil entering the oil chamber 18' is also lower than that of the oil inlet boat 12'.
The pressure applied to the diaphragm 13' that moves the valve body 9' upward (in the closing direction) is small, and the force of the spring 14' cannot be overcome, resulting in the valve body remaining open. However, as the pressure of the supplied oil increases, the force applied to the oil chamber 18 increases, and the valve body 9
′ and moves in the closing direction. (In the upper part of Japan.

The installed spring 14' and bolt 15' are used to adjust the pressure on the outlet side.) When the pump 1 starts up, it is unable to follow the pressure increase due to the responsiveness of the pressure reducing mechanism of the regulating valve. The valve opening degree and secondary hydraulic characteristics will be distorted as shown in Fig. 4. This is because when the pump is started, the pressure on the outlet side (secondary side) of the pressure regulating valve 8 is OK and the valve is fully open, and it remains fully open immediately after starting. be. This characteristic is shown in FIG.

The pressure and secondary oil pressure (adjustment valve inlet side) characteristics at pump startup are shown in A1. The hydraulic characteristics of the regulating valve outlet (secondary side) are shown in A4. Assuming that the pressure during normal operation is P4 and the piping design pressure is P3', the peak of the secondary hydraulic pressure is:
P3 will fall and the design pressure will be exceeded. This adversely affects bearings and instruments.

The present invention aims to protect turbine lubricating oil equipment by adjusting this pressure fluctuation.

The structure (mechanism) of the bearing oil supply pressure adjustment device is shown in Fig. 1.

In this device, the structure of the secondary pressure regulating valve is such that the oil inflow boat 12' on the outlet side is removed and a boat 32 from the pressure regulating device E is provided.

The pressure regulator E guides the unreduced hydraulic pressure from the startup special pipe 7 to the pipe 26, restricts the flow rate with the orifice 29, and then lowers the hydraulic pressure slightly below the bearing oil supply pressure with the safety valve 30, and then controls the pipe 27. Through this, oil is supplied to the lower boat D of the pilot housing 20, the accumulator 31, and the pilot valve boat A. Oil flows from boat A to boat B, flows into the valve body driving section of pressure regulating valve 8, and moves the regulating valve in the closing direction. However, as oil flows into the accumulator 31, the partial pressure of oil from the pipe 19 decreases, so the valve body 9 gradually closes, and the pressure rise curve becomes as shown in F3 in FIG. The slope becomes gentle. Furthermore, when the pump is started, as the oil pressure increases, the oil pressure supplied from the boat D causes the valve body of the pilot valve to overcome the force of the spring 23 installed above the pilot.
It moves upward, causing oil to flow into ports G and B, controlling the secondary side (outlet side) hydraulic pressure of the pressure regulating valve 8, and making a smooth transition. FIG. 5 shows a state in which the pressure control on the outlet side has been started.

Figure 8 shows the secondary pressure change when this mechanism is used.

The secondary pressure has no pressure peaks as shown in FIG. 6, and smoothly transitions to the normal operating pressure P4.

FIG. 9 shows an embodiment using an electromagnetic pilot.

The difference with the hydraulic pilot is shown below.

When the pump 1 is started, a signal from the start switch is input to the timer 35 via the input line 36.

This timer stops the electricity going to the coil of the solenoid valve pilot 33 for a certain period of time after activation. The time length can be indicated by Ta in FIG.

After 13 hours, electricity energizes the coil of the electromagnetic pilot 33 and switches the pilot valve boat.

〔Effect of the invention〕

According to the present invention, in the bearing oil supply system of the turbine lubricating oil system, the problem is due to excessive pressure fluctuations in the bearing oil supply pressure. Instrumentation-related malfunctions, specifically, pressure damage and malfunctions of the instrumentation itself. These include all system instruments such as pressure gauges and pressure switches. Also, due to high pressure,
The design pressure on the outlet side of the regulating valve may be exceeded, creating a danger to the piping itself.

All of these can be prevented and high reliability can be ensured. Further, the present invention has a wide range of application not only to commercial turbines but also to industrial turbines.

[Brief explanation of drawings]

Fig. 1 is a system diagram of a steam turbine lubricating oil bearing oil supply pressure regulating device according to an embodiment of the present invention, Fig. 2 is a schematic diagram of a lubricating oil supply system, Fig. 3 is a configuration diagram of a conventional pressure regulating valve, and Fig. 4 is a schematic diagram of a lubricating oil supply system. The figure shows the characteristic curve of the pressure regulating valve opening and the pressure on the outlet side of the regulating valve, Figure 5 shows the state of the pressure regulator during normal operation, and Figure 6 shows the conventional primary pressure and secondary pressure of the pressure regulating valve. Characteristic curve diagram, Figure 7 is a characteristic curve diagram of primary pressure and secondary pressure when the pressure regulator is installed, Figure 8 is a secondary positive characteristic curve diagram when actual operation begins, and Figure 9 is a diagram of the electromagnetic pilot. It is a block diagram of the Example used. 1...
Main oil pump, 2...Main oil pump, 3...Emergency oil pump, 5...-Water pressure adjustment valve, 6...Oil cooler, 7
...Bearing oil supply piping, 8...Secondary pressure regulating valve, 29.
... Orifice, 30 ... Safety valve, 31 ... Accumulator, 33 ... Solenoid valve, 34 ... Electrical wiring.

Claims (1)

[Claims] 1. As a pressure regulating device, pipes are taken out from the inlet and outlet sides of the pressure regulating valve, and piping is installed to supply oil used for pressure regulating valve operation. An orifice and a safety valve are installed in the piping, and an accumulator and a pressure regulating valve control pilot valve are installed. A bearing oil supply pressure regulating device characterized by having a mechanism for shifting control to control using hydraulic pressure on the outlet side of a pressure regulating valve.