JPS6069214A - Nozzle for geothermal turbine - Google Patents

Abstract

PURPOSE:To prevent nozzle surface from the adhesion of scale by a method wherein high pressure water is spouted out from the surface of a nozzle for a terrestrial heat turbine. CONSTITUTION:A water introducing hole 3 is penetrated and bored, in the nozzle height direction, in the vicinity of the central part of the first stage nozzle 1 of a terrestrial heat turbine. A water spouting out hole 4 is bored, from the ventral surface of the nozzle, at nearly intermediate position for the nozzle height of the water introducing hole 3, the hole 4 is bored to be perpendicularly intersected with the water introducing hole 3, also communicated with the water introducing hole 3. By such a structure, a pressured water 5 is spouted out from the spouting out hole 4, consequently, the scale 2 adhered on the back-surface of the nozzle can be removed, accordingly, the nozzle surface can be prevented from adhesion of the scale.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a geothermal turbine nozzle from which scale can be easily removed.

The geothermal steam sent to the geothermal turbine contains silica (Sio
2) Because impurities such as salt (Nacz) are dissolved to a large or small degree, the pressure of the geothermal steam drops inside the first stage nozzle 1 of the geothermal turbine, as shown in Figure 1. During this process, the impurities precipitate, forming scale 2 and depositing on the back outlet side of the nozzle.As a result, the flow path area of the nozzle decreases and the amount of steam sent into the geothermal turbine decreases. is reduced, so the turbine output is significantly reduced. If the impurities exceed 1,100 pp and have dissolved into the geothermal steam, the above-mentioned phenomenon (1) will occur particularly markedly and the output will decrease within several hours of operation, so the turbine casing of the turbine should not be Open nozzle 1
It is said that it is necessary to remove scale 2, which is deposited on the back side of the To this end, one solution is to suppress the content of impurities in geothermal steam to a low level, but this requires the installation of large-scale external impurity removal equipment upstream of the geothermal turbine. If the purity of the steam or hot water is poor, a binary cycle device, which requires high equipment costs, must be used, and an economical method is desired.

The present invention was made in view of the current situation, and provides a nozzle for a geothermal turbine that removes scale adhering to the surface of the nozzle or prevents the adhesion of scale by jetting high-pressure water from the nozzle surface. The aim is to eliminate the drawbacks of the prior art.

Next, an explanation will be given with reference to drawings showing an embodiment of the present invention. In Fig. 2, a water passage hole is provided near the center of the first stage nozzle 1 of a geothermal turbine in the nozzle height direction, that is, in the radial direction (2). 3 is drilled through the nozzle, and an ejection hole 4 is drilled from the ventral surface of the nozzle at a right angle to the water hole at a position near half the height of the nozzle.

Therefore, according to the present invention, when pressurized water is passed through the water passage hole 3 from the outside, the pressure water is suddenly jetted out from the jetting hole 4, so that the jetting direction of the jetting hole is changed from the scale 2 of the adjacent nozzle. If it is set so as to face the back outlet side where adhesion occurs, the water 5 jetted from the jet hole 4 will destroy and blow away the scale, making it easy to remove the scale, and needless to say, the removal process will be easier. There is no need to disassemble and open the turbine casing during operation.

Further, in FIG. 3 showing another embodiment of the present invention,
The nozzle 1 is formed into a hollow shape 6, and a large number of small ejection holes 7 are bored over the entire surface of the nozzle.

Therefore, in other embodiments of the present invention, scale adhesion will not occur if high-pressure water is jetted out from the jetting holes 7 on the nozzle surface, so if the high-pressure water is jetted out constantly or periodically. , it is possible to easily prevent adhesion as well as remove adhesion scale, and in this case, it is not necessary to open the turbine casing at all as in the case described above.

As mentioned above, when the turbine output is reduced due to scale adhesion, conventionally the turbine casing is opened to remove the adhering scale, but the present invention removes the adhering scale and removes the scale while the turbine casing is open. It is economical because it prevents adhesion, making it possible to generate electricity even in areas with high impurity concentrations where geothermal power generation was previously considered impossible. It also simplifies the impurity removal equipment upstream of the turbine. This invention has high industrial utility value, as it can be put to practical use.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional plan view showing the main part of a nozzle of a conventional geothermal power generation turbine, FIG. 2 is a cross-sectional plan view of the main part showing an embodiment of the present invention, and FIG. FIG. 2 is a cross-sectional plan view of main parts showing an example. (3) 1.Nozzle, 2.Scale, 311.Water hole, 4.
・Gouting hole, 5..Gouting water, 6..Hollow nozzle, 7..
Gushing hole. (4) Figure 1 Figure 2 Figure 5

Claims (1)

[Claims] A nozzle for geothermal turbines that is characterized by spouting high-pressure water from the nozzle surface.