JPS5817326B2 - total flow turbine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a total flow turbine that allows the use of straight blades.

A total flow turbine uses high-speed two-phase flow obtained by expanding saturated hot water through a nozzle to rotate rotor blades, but it has never been put to practical use and is currently in the experimental stage. be.

However, there are plans for this type of turbine to be used for geothermal power generation, etc., and as the capacity increases, problems will naturally arise due to the length of the rotor blades.

In other words, increasing the length of the rotor blade results in a large circumferential speed difference between the root side and the tip side of the rotor blade, which inevitably necessitates the use of twisted blades.

It is obvious that the above-mentioned twisted wing requires advanced technology not only in design but also in construction.

Therefore, it is desirable to develop a turbine structure that allows the use of a straight grate that does not require particularly sophisticated technology.

The present invention aims to provide a turbine structure that can employ a straight grade for a large-capacity total flow turbine, and is applied to geothermal plants and various waste heat utilization plants.

The invention will now be described in detail with reference to preferred embodiments illustrated in the accompanying drawings.

FIG. 1 is a cross-sectional view showing the main structure of a total flow turbine according to the present invention, FIG. 2 is an enlarged partial cross-sectional view of the tip side nozzle portion of FIG. 1, and FIG. 3 is a cross-sectional view of FIG. FIG.

In the figure, a plurality of blades 11 are untwisted straight blades that are installed radially on the outer periphery of the turbine disk 10 .

Further, the chips are held in series by a shroud 12.

The labyrinth packing 21 is provided in the gap between the casing 20 and the shroud 12 to prevent leakage of steam.

The nozzles 30, 31, and 32 are provided so as to divide the steam hitting the blade 11 into three parts in the longitudinal direction of the blade 11.

Further, the nozzle chambers 40, 41 and 42 are each communicated with a saturated hot water tank (not shown) through a pipe line, and the nozzles 40. It's a pool.

The conduit 50 is a steam passage led from above the nozzle chamber 40 provided at the root [jl of the blade 11 to the nozzle 32 provided on the chip side, and a steam reservoir provided surrounding the nozzle 32. It opens at 51.

The spout 52 is formed in the nozzle 32 in a ring shape around the axis of the nozzle 32 and communicates with the steam reservoir 51 .

Next, the effects of the total flow turbine of the present invention will be described.

Saturated steam (flash steam) and saturated hot water are mixed in each of the nozzle chambers 40, 41, and 42, but the flash steam is slightly separated and collected in the upper part.

A part of this flash steam in the root side nozzle chamber 40,
A conduit 50 leads to the tip side nozzle 32 and the nozzle chamber 42
When it is ejected from the ejection hole 52 together with flash steam,
The steam outflow method is faster from the tip side nozzle 32 than from the root side nozzle 30.

The principle is: () The theoretical velocity obtained when saturated hot water expands is expressed as:

As can be seen from the steam table (i-s diagram), the isobars are wider on the saturated steam side than on the saturated hot water side, so id'
iIs>io'ilw.

Therefore, CIs>CIW.

According to the above, when flash steam (saturated steam) is guided to the tip side nozzle 32, the outflow speed of the tip side nozzle 32 increases.

The velocity triangle in the case where the conduit 50 is not provided in FIG.
The figure shows a velocity triangle when a conduit 50 is provided.

here, C: nozzle outflow speed, W: Relative inflow speed of rotor blades U: Circumferential speed α: Nozzle outflow angle β: Relative inflow angle of rotor blades Subscript R: Root T: Chip represents.

In FIG. 4, the rotor blade relative inflow angle β is different between the root side and the tip side, whereas in the present invention provided with the conduit 50 shown in FIG. 5, the rotor blade relative inflow angle β is different between the root side and the tip side. They can be made almost equal.

Therefore, the outflow velocity of each of the three divided nozzles becomes faster in the order of the intermediate part on the root side and the tip side, and accordingly, the relative inflow angle of the rotor blades can be made approximately equal for all three nozzles.

This makes it possible to use a straight blade.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the main part configuration of a 1-Tar flow turbine according to the present invention, FIG. 2 is an enlarged partial cross-sectional view of the tip side nozzle portion of FIG. 1, and FIG. -M line arrow view, FIG. 4 is a velocity triangular diagram when no conduit is provided, and FIG. 5 is a velocity triangular diagram when a conduit is provided. 10... Turbine disk, 11...
Blade, 12...Shroud, 20...
...Casing, 21...Labyrinth packing, 30,31.32...Nozzle, 40,41.
42... Nozzle chamber, 50. ... Conduit, 5
1... Steam pool.

Claims (1)

[Claims] 1 A plurality of nozzles and a nozzle chamber communicating with each nozzle are provided in the longitudinal direction of the turbine blade, and a part of the flash steam in the nozzle chamber on the root side of the turbine blade is guided to the tip side nozzle. A total flow turbine characterized in that the upper part of the nozzle chamber and the inner surface of the nozzle on the chip side communicate with each other.