JPH0235859B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lubricating oil supply device for a small gas turbine.

[Conventional technology and its issues]

Generally, bearings for compressors and turbine wheels in gas turbines are used at higher speeds and lower loads than bearings for piston engines. Therefore, the role of lubricating oil is more focused on cooling the heat generated in the bearing than on lubrication. In other words, in the case of a rolling bearing for a gas turbine, the DN axis (the value obtained by multiplying the bearing inner diameter in mm by the rotational speed in γpm), which is one of the indicators of heat generation in the bearing, is over 111,000,000. Since high heat is applied to the bearings on the turbine wheel side, jet lubrication cooling, which balances the jets of lubricating oil, is essential.

On the other hand, there are two types of gas passages that lead from the combustor outlet to the first-stage gas turbine nozzle in gas turbines: a scroll type and a plenum type. It has the advantage of reducing the load on the turbine stationary blades by providing a pre-swirling flow to the turbine.

However, for small and compact gas turbines that employ this scroll-type gas passage, the scroll has a structure that is greatly hollowed out and curved toward the compressor side.
54-69205), when trying to lubricate and cool the bearing on the turbine wheel side, the lubricating oil supply path is obstructed by this scroll, making it impossible to construct a lubricating oil supply path using a drilled hole. Difficulty (for example, oil passage 13 in Japanese Utility Model Application Publication No. 57-33 cannot be formed);
Or it becomes a combination of multiple drill holes (Jet Kai 56-
(Refer to Publication No. 163725).

Therefore, it is conceivable to adopt a lubricating oil supply path (see Utility Model Publication No. 43-26162) using a conduit (oil supply pipe) and arrange it along the scroll. There is a problem in that it gets heated and lubrication and cooling are not performed.

[Means to solve the problem]

Therefore, the present invention was created to solve these problems, and its gist is as follows:
Compressor A disposed within turbine housing 18
The axle shaft of the impeller 1 and the turbine axle 12 of the turbine impeller C are coaxially integrated, and these shafts are supported by a bearing 15 provided between the impeller 1 and the turbine impeller C. At the same time, the first-stage turbine nozzle 7 of the turbine impeller C and the combustor inner cylinder 4 to which the compressed air from the impeller 1 is supplied are communicated by a scroll 6, and the scroll 6 is connected to the compressor A side. In a small gas turbine arranged in a curved manner, a lubricating oil supply passage 19 provided in the turbine housing 18 and an oil supply portion of the bearing 15 are communicated through an oil supply pipe 21, and a lubricating oil supply passage 19 is provided at the outlet of the impeller 1. An air jacket chamber is formed by a support body 13 in which a differential user 2 is formed on the tip side and whose base side is connected to the housing for the bearing 15, and a heat shield plate 27 provided on the scroll 6 side and in a non-contact state therewith. This is a lubricating oil supply device for a small gas turbine, in which the oil supply pipe 21 is arranged inside the air jacket chamber.

〔Example〕

Hereinafter, the structure of the present invention will be described in detail based on embodiments shown in the accompanying drawings.

Fig. 1 is an overall side sectional view of an embodiment of the present invention;
The figure shows a sectional view of the main part. The one shown in Fig. 1 is a small gas turbine directly connected to a generator, where A is a compressor, B is a combustor, and C is a turbine wheel.

In the compressor A, 1 is an impeller, 2 is a diffuser, and 3 is a discharge part.

In the combustor B, 4 is a combustor inner cylinder, 5 is a fuel injection valve, 6 is a scroll forming a gas passage for introducing combustion gas from the combustor inner cylinder 4 to the first stage turbine nozzle 7 of the turbine impeller C, This scroll 6 also forms a flow path that guides compressed air from the discharge section 3 to the combustor inner cylinder 4.

In the turbine wheel C, 8 is the first stage bucket,
9 is a second stage turbine nozzle, 10 is a second stage bucket, 11 is an exhaust casing, and 12 is a turbine axle. The axle 12 is supported by the impeller 1 and a turbine-side bearing housing and a compressor-side bearing housing that are connected to the impeller 1 and the axle.

Next, the diff user 2 moves the cone-shaped support 13
The cone-shaped support 13 has a cylindrical body 14 at its base, and this cylindrical body 1
4 forms a bearing housing on the turbine wheel side. The base of the first stage turbine nozzle 7 is fixed to the outer peripheral surface of this cylindrical body 14.
4, a rolling bearing 15 is fitted in the center, a labyrinth seal 16 is fitted on one side, and a metal 17 is fitted on the other side, through which the turbine axle 12 is inserted.

D is a gearbox with a built-in speed reducer, and an oil pan (not shown) is provided at the bottom of the gearbox D. A lubricating oil pump P is connected to the oil pan from this oil pan.
Lubricant is sucked through the oil cooler O,
It supplies oil to the necessary cylinder locations (for example, reduction gear bearings, gears, etc.) and also supplies oil to the bearing housing on the turbine wheel side.

That is, as shown in FIG. 2, a pipe joint 20 is screwed into a drill hole 19 drilled in the turbine housing 18 near the differential user 2, and the pipe joint 2
The oil supply pipe 21 connected to the cylindrical body 14 is connected to a pipe joint 22 implanted in the cylindrical body 14. Jet nozzles 23 and 24 are provided in this cylindrical body 14 so as to face the rolling bearing 15, and lubricating oil is jet-lubricated.

These jet nozzles 2 in the cylinder 14
On the opposite side of 3 and 24, another pipe joint 25 is installed between the labyrinth seal 16 and the rolling bearing 15, and an oil pipe 26 is connected to this pipe joint 25. This oil feed pipe 26 is connected to the oil pan through a return passage.

These oil supply pipe 21 and oil supply pipe 26
is piped close to the outer surface of the scroll 6. A heat shield plate 27 is provided from the discharge part 3 side of the cone-shaped support 13 to the first stage turbine nozzle 7 side of the cylindrical body 14. , these pipes 21 and 26 are covered to block heat from the scroll 6. That is, the support body 13 and the heat shield plate 27 constitute an air jacket chamber, and these pipes 21 and 26 are arranged in this air jacket chamber.

Next, the operation of this embodiment will be described. Air rotates together with the impeller 1, is compressed, becomes high pressure, and flows out from the impeller 1 with speed. The velocity energy of this compressed air is converted into pressure energy by the differential user 2. Compressed air exiting the diffuser 2 is guided around the outer periphery of the scroll 6 and introduced into the combustor B. In the combustor inner cylinder 4, the fuel injection valve 5
The fuel is injected, mixed with the introduced compressed air, and combusted to form high-pressure combustion gas. This combustion gas reaches a temperature of approximately 1000° C. and is introduced into the first-stage turbine nozzle 7 through the scroll 6. The pressure decreases at each stage of the turbine and is converted into mechanical energy, which rotates the turbine axle 12 at high speed.

The lubricating oil from the oil pan flows through the oil supply pipe 21 → pipe joint 22 → jet nozzles 23, 24.
This jet lubricates the rolling bearing 15.

〔Effect of the invention〕

According to the present invention, the following effects can be expected.

The first stage turbine nozzle 7 and the combustor inner cylinder 4 are connected through a scroll 6, and this scroll 6
Since the scroll 6 is curved toward the compressor A side, a pre-swirl flow is given to the combustion gas to reduce the load on the turbine stationary blades, and the entire gas turbine can be made more compact. Since the oil supply pipe 21 is also adopted, the bearing 1 provided between the impeller 1 and the turbine impeller C
You can detour to 5 even if you are blocked by scroll 6.
Lubricated cooling is possible without any problems.

Moreover, since this oil supply pipe 21 is arranged inside the air jacket chamber, it is not directly heated by the heat (radiant heat, heat conduction) from the scroll 6, and therefore the lubricating oil does not reach a high temperature, and the above-mentioned lubrication This is convenient for cooling.

In addition, since this air jacket chamber is constituted by the support body 13 which forms the diffuser 2 on the tip side and is connected to the bearing housing, and the heat shield plate 27, the air jacket chamber is able to absorb a large amount of compressed air flowing out from the impeller 1. Since the air jacket chamber itself is surrounded by the air flow (in other words, the air jacket chamber itself is exposed to the compressed air flow), the air jacket chamber itself does not reach a high temperature, and as a result, the lubricating oil flowing through the oil supply pipe 21 is not heated and is incompatible with the above. Standing down,
It is even more convenient for lubricant cooling.

In general, the scroll 6 is curved toward the compressor A side, and the compressor A and the turbine wheel C are brought closer together to form a small and compact gas turbine. Although high heat will be transferred,
Since the lubricating oil flowing through the oil supply pipe 21 is at a low temperature, the bearing 15 can be reliably lubricated and cooled.

[Brief explanation of drawings]

FIG. 1 is an overall sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view of a main part. 6...Scroll, 15...Rolling bearing, 21...
Oil supply pipe, 27...heat shield plate.

Claims (1)

[Claims] 1. The axle of the impeller 1 of the compressor A disposed in the turbine housing 18 and the turbine axle 12 of the turbine impeller C are coaxially integrated, and the impeller 1
and the turbine wheel C.
The first-stage turbine nozzle 7 of the turbine impeller C and the combustor inner cylinder 4 to which the compressed air from the impeller 1 is supplied are connected by a scroll 6. In the small gas turbine arranged curved toward the compressor A side, the lubricating oil supply passage 19 provided in the turbine housing 18 and the oil supply portion of the bearing 15 are communicated with each other through an oil supply pipe 21, and the impeller a support body 13 having a differential user 2 provided at the outlet of the scroll 6 on its tip side and connected to the housing for the bearing 15 on its base side; and a heat shielding plate 27 provided on the scroll 6 side and in a non-contact state therewith. A lubricating oil supply device for a small gas turbine, in which an air jacket chamber is formed by the above, and the oil supply pipe 21 is disposed within the air jacket chamber.