JPH0417552A - Seal oil supply device for rotary electric machine - Google Patents

Abstract

PURPOSE:To supply stable seal oil by providing a branch pipe and a throttle device on the downstream side of the differential pressure between a vacuum vessel, which supplies a rotary electric machine of gas cooling system with shaft sealing oil and the rotary electric machine so as to return some of the sealing oil. CONSTITUTION:Required seal oil is supplied from a vacuum vessel 5 to the rotary shaft sealing mechanisms 2 and 3 of a turbine generator 1 through a working seal oil pump 8 or an emergency seal oil pump 15 and a differential pressure adjusting valve 18 fully opened and a pipe 8. When the generator stops or required quantity of seal oil is small, an operation controller 24 opens the throttle device 20 on the downstream of the differential pressure adjusting valve 18 with an operation valve 21, receiving the signals from a rotational inspection device 22 and a pressure inspection device 23, and returns the seal oil outputted by the differential pressure adjusting valve 18 to the vacuum vessel 5 through a pipe 6. Hereby, the operation range of the differential pressure adjusting valve 18 is stabilized, and even to the required quantity of seal oil over the wide ranges of shaft sealing mechanisms 2 and 3, stably supply of seal oil is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a shaft sealing oil supply device used in hydrogen-cooled rotating electric machines and the like.

(Prior Art) Generally, in hydrogen-cooled rotating electric machines, especially turbine generators, a sealing oil supply device supplies sealing oil at a required pressure to prevent hydrogen gas from leaking to the outside through the shaft penetrating portion of the stator. We have a supply system.

FIG. 3 shows a conventional sealing oil supply system, in which ■ is a turbine generator, ■ (3) is a shaft sealing mechanism for sealing the hydrogen gas sealed in the turbine generator (1), and ( b) is an oil pipe for supplying sealing oil to the shaft sealing mechanism ■■, ■ is a vacuum tank that stores oil from the bearing oil supply system supply pipe
) is a regular sealed oil pump, (9) is an emergency sealed oil pump (
15) Check valve to prevent backflow of sealing oil from (10)
is a hydraulic control valve for maintaining and adjusting the discharge pressure of the regular sealed oil pump (2) to a predetermined value, and is configured so that part or all of the discharge amount of the regular sealed oil pump (2) can be returned to the vacuum tank (2).

(15) is the emergency seal oil pump, (16) is a check valve that prevents backflow from the regular seal oil pump (toward), and (17) is to set the discharge pressure of the emergency seal oil pump (15) to a predetermined value. A hydraulic control valve (1g) for maintenance and adjustment uses seal oil from the regular seal oil circuit or the emergency seal oil circuit to adjust the valve opening depending on various conditions such as the rotation speed of the turbine generator and the in-machine hydrogen gas pressure. This is a differential pressure control valve that automatically adjusts the pressure. The effect is that the sealing oil in the vacuum tank (1) is adjusted to an appropriate sealing oil pressure by the regular sealing oil pump (c) and the hydraulic pressure control valve (10), and the shaft sealing oil is Supplied to the mechanism ■■.

In this case, if the discharge pressure of the regular seal oil pump ■ decreases due to a loss of AC power to the regular seal oil pump (c) or a failure of the drive motor of the regular seal oil pump ■, the pressure detection device is set to the specified oil pressure. (12) is operated to start the emergency seal oil pump (15), and the supply of seal oil is switched to the emergency seal oil pump (15).

(Problem to be solved by the invention) By the way, such a conventional sealing oil supply device.

In particular, when sealing oil with a pressure higher than the hydrogen gas pressure inside the machine is supplied to the shaft sealing mechanism ■■ by the regular sealing oil pump ■ or the emergency sealing oil pump (15) and the oil film maintains the airtightness, hydrogen gas inside the machine is sealed, the sealing oil supply device must continue to operate regardless of the hydrogen gas pressure inside the machine, such as when the rotating electric machine is stopped, running, tanning, etc.

The differential pressure regulating valve (18) employs a spool valve type that can automatically control the in-machine hydrogen gas pressure and sealing oil supply pressure to maintain the normal differential pressure of about 0.5 kg/cd. This valve is connected to the piston (19) as shown in Figure 2.
Upper chambers (20
) and the lower chamber (21), hydraulic pressure corresponding to the in-flight gas pressure and sealing oil pressure is introduced, and in order to maintain this differential pressure at approximately 0.5 kg/d, the spring force installed in the upper chamber pushes the cylinder downward. Move the piston (19) and move the piston (19)
The pressure is adjusted with a port that has holes in the circumferential direction of the spool.

On the other hand, the amount of oil required to be supplied to the rotating electric machine varies greatly depending on the state of the rotating electric machine, that is, when it is stopped, when it is running, and the internal hydrogen gas pressure1.If the maximum is 100, the minimum is 1.
In some cases, the degree of In addition, the pressure on the inlet side of the differential pressure control valve (18) varies between the pressures adjusted by the hydraulic pressure control valves (10) and (17) in the case of normal seal oil circuit operation and in the case of emergency seal oil circuit operation. In addition, the difference in pressure loss between the inlet side pressure and the outlet side of the differential pressure regulating valve also varies greatly depending on the operating conditions of the rotating electric machine. (up to about 10 kg/a
l) may occur.

That is, since the sizing of the differential pressure regulating valve (18) is normally determined based on the maximum amount of supplied oil, when the flow rate is small as described above, the valve boat is operated with the valve boat nearly fully open. In this case, the higher pressure on the inlet side than the gap between the piston and the sleeve enters the outlet side, and as a result, the outlet side pressure becomes higher than the lower chamber pressure, and the pressure difference pushes the piston downward, and the high pressure on the inlet side increases. Since the sealing oil supply pressure becomes the sealing oil supply pressure without being able to sufficiently reduce the pressure, normally the differential pressure between the sealing oil pressure and the in-machine hydrogen gas pressure is 0.5 kg/d, but at the above-mentioned small flow rate, the pressure difference is 1.0 to 1.5 kg. /a#, which caused the inconvenience of exceeding the control range.

On the other hand, during a transient period when the regular seal oil pump (c) switches to the emergency seal oil pump (15) due to a malfunction or power loss, etc., the inlet side pressure changes rapidly and becomes a large pressure, and the differential pressure control valve The pressure on the outlet side of the rotating electrical machine increases, causing the piston to be pushed downward and back upward, resulting in a continuation of unstable sealing oil pressure.6 The object of the present invention is to To provide a sealing oil supply device for a rotating electrical machine that can supply an appropriate sealing pressure and maintain a normal differential pressure even in an operating state.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides an operating valve on a branch pipe branched from the downstream pipe of the differential pressure regulating valve (18), and also provides a throttle device, with the other end connected to a vacuum chamber. Connect the oil supply pipe 0 to ■. On the other hand, the first operating valve is opened and closed by an operating valve controller based on the rotational speed of the rotating electrical machine and the internal pressure of the machine.

When the amount of sealing oil is small, open the operating valve and open the differential pressure control valve (18
) By increasing the amount of sealing oil that passes through the valve, an appropriate differential pressure can be maintained and the desired purpose can be achieved.

(Function) As a result, in the present invention, when the amount of oil required to be supplied to the rotating electric machine is minimum, the piston inside the differential pressure regulating valve (18) is automatically operated in the fully closed direction, but the operating valve is not opened. By operating the differential pressure regulating valve (18), the amount of sealing oil passing through the differential pressure regulating valve (18) increases. This increased amount of sealing oil is supplied to the supply pipe (2) through the operating valve (21), forming a return loop. On the other hand, the amount of sealing oil required for rotating electric machines has increased, and the differential pressure control valve (18
), the operating valve (21) branched from the downstream piping of the differential pressure regulating valve (18)
) is operated in a fully closed manner, and a return loop for sealing oil to supply pipe 0 is not configured. That is, in this state, sealing oil pressure with an appropriate differential pressure can be supplied to the shaft sealing oil mechanism section (■).

(Example) An example of the present invention will be described below with reference to FIG. In FIG. 1, the same parts as in FIGS. 3 and 2 are given the same reference numerals, and their explanation will be omitted.

The differential pressure regulating valve (18) is branched from the downstream piping and communicates with the supply pipe 0 via the throttle device (20) and the operating valve (21).

On the other hand, the 1 operation valve (21) is the rotation speed inspection device (
22) and the pressure inspection device (23), the operating valve controller (
24).

The relationship between the rotation speed of the rotating electrical machine ■ and the required amount of sealing oil for the internal pressure car has been measured in advance, and the differential pressure I! Regarding the I-node valve (18), the range in which differential pressure can be properly controlled has been determined through actual measurements. Next, the effect will be explained.

When the rotating electric machine ■ is stopped or the internal hydrogen gas pressure is low, the amount of sealing oil supplied to the shaft sealing mechanism ■■ will be very small.
The differential pressure regulating valve (18) will no longer be able to maintain an appropriate differential pressure. Under these conditions, the operating valve (21) is automatically opened in response to a signal from the operating valve controller (24) due to the relationship between the number of rotations and the amount of sealing oil required for the internal pressure car.

When the operating valve (21) is opened, the amount of sealing oil to the differential pressure regulating valve (18) increases, making it possible to maintain an appropriate differential pressure.

In addition, when the rotational speed of the rotating electric machine (■) and the internal hydrogen gas pressure are operated at the rated conditions, the amount of sealing oil required for the shaft sealing mechanism 20 increases, so the operating valve controller (24) 18) Controlled to fully closed operation, sealing oil does not flow to the supply pipe (■).

The operating valve (21) has a throttle device (20) arranged in series.
This is for adjusting oil pressure fluctuations during a transient period when the operating valve (21) is opened, and is adjusted in advance. Also, the operating valve (2
1) can be opened and closed by a manual signal from the operation controller (24), and the rotation inspection device (24)
Similar effects can be obtained even without the signals from 2) and the pressure testing device (23).

By supplying an amount of sealing oil that maintains an appropriate differential pressure to the differential pressure WR control valve (18) under various operation stop conditions of these rotating electric machines (1), stable operation can be achieved.

〔Effect of the invention〕

As described in detail above, according to the configuration of the present invention, depending on the operating conditions of the rotating electrical machine (2), the downstream side seal oil supply circuit of the differential pressure regulating valve (18) is controlled to operate the shaft sealing mechanism section (2) and the branch piping. By supplying to the valve (21) side.

It has excellent effects such as being able to supply stable sealing oil without causing problems due to high differential pressure, and maintaining a constant differential pressure even when operating conditions change.

[Brief explanation of drawings]

FIG. 1 is a piping system diagram of a sealing oil supply device showing an embodiment of the present invention, FIG. 2 is a structural diagram of a differential pressure regulating valve, and FIG. 3 is a piping system diagram of a conventional sealing oil supply device. 1... Turbine generator 2, 3... Shaft sealing mechanism 5.
・・Vacuum tank 8・Sealed oil pump 12・
・・Pressure detection device 15 ・・Emergency seal oil pump 18
... Differential pressure regulating valve 19 ... Piston 20 ...
Upper chamber 21...lower chamber

Claims (3)

[Claims] (1) A vacuum tank that stores seal oil for supplying seal oil to the shaft seal oil mechanism of the rotating electric machine, which has cooling gas sealed inside, and a regular seal oil pump to pump the seal oil from this vacuum tank. and a system for supplying the shaft sealing mechanism via a pressure regulating valve, a branch pipe is arranged from the downstream side of the differential pressure regulating valve, and a throttle device and an operating valve are arranged on the pipe. A sealing oil supply device for a rotating electric machine, characterized in that a part of the sealing oil is returned to a vacuum tank supply pipe. (2) The operating valve is provided with a solenoid valve, and the solenoid valve is closed in response to a signal that detects that the discharge pressure of the regular sealed oil pump has fallen below a predetermined value. A sealing oil supply device for a rotating electric machine as described in . (3) The sealing oil supply device for a rotating electrical machine according to claim 1, wherein the opening and closing operation of the operating valve is performed based on the rotational speed of the rotating electrical machine and the pressure of cooling gas.