DE457853C

DE457853C - Guide device for axial steam or gas turbines

Info

Publication number: DE457853C
Application number: DEE29141D
Authority: DE
Original assignee: Erste Bruenner Maschinen Fabriks Gesellschaft
Current assignee: Erste Bruenner Maschinen Fabriks Gesellschaft
Priority date: 1923-03-06
Filing date: 1923-03-06
Publication date: 1928-03-24

Description

Turbinenschaufeln, die in ihrer Längenrichtung verschiedene Winkelverhältnisse oder ungleiche Querschnitte oder beides besitzen, sind bereits bekannt. Durch diese Schaufelausführungen sollen bei axialen Dampf- oder Gasturbinen, insbesondere in den letzten Reihen der Turbine, in welchen die Schaufeln im Verhältnis zum Durchmesser der Trommel oder Scheibe lang sind., die nachteiligen Wirkungen der fächerförmig auseinanderstehenden Schaufeln und die der langen Endschaufeln selbst aufgehoben werden. Die Beseitigung des Nachteiles der langen Endschaufeln der Axialturbinen ist jedoch nur teilweise möglich, da wegen des großen Unterschiedes in der Schaufelteilung am Schaufelkopf und Schaufelfuß ungünstig wirkende Strömungsquerschnitte für das Treibmittel innerhalb der Schaufelzellen verbleiben, die energiezehrend wirken.Turbine blades that have different or unequal angular ratios in their length direction Cross-sections or both are already known. With these blade designs should in axial steam or gas turbines, especially in the last rows of the turbine, in which the blades in the Relation to the diameter of the drum or disk are long., The adverse effects of the fan-shaped spaced blades and those of the long end blades themselves. The elimination however, the disadvantage of the long end blades of the axial turbines is only partial possible because of the large difference in the blade pitch at the blade head and Blade root unfavorably acting flow cross-sections for the propellant within of the blade cells remain, which have an energy-consuming effect.

Es wurde auch bereits vorgeschlagen, den Schaufelradkranz der Turbine durch Querstege in konzentrische Schaufelkränze zu unterteilen. Diese Maßnahme ist aber unzureichend gegenüber der nachteiligen Fächer· wirkung, weil die am äußersten Umfange liegenden Treibmittelzellen zu viel Treibmittel schlucken und dieses schlecht verarbeiten, da die Abstände zwischen den Schaufeln und auch deren radiale Erweiterung bereits zu groß sind.It has also already been proposed to use crossbars for the impeller ring of the turbine to be subdivided into concentric blade rings. However, this measure is insufficient compared to the disadvantageous fan effect, because those on the outermost circumference Propellant cells swallow too much propellant and process it poorly, because the distances between the blades and their radial expansion are already increasing are great.

Die vorliegende Erfindung betrifft eine Leitvorrichtung für axiale Dampf- oder Gasturbinen, bei welcher die beiden an sich bekannten Einrichtungen, nämlich der Verwindung der Schaufeln und der Unterteilung der Kanäle vereinigt sind. Die Erfindung besteht darin, daß unter Beibehaltung von Schaufeln mit gleichbleibender Schaufelbreite einerseits durch stetiges Verkleinern der Austrittswinkel radial von innen nach außen die Leitkanalquerschnitte in der gleichen Weise allmählich abnehmen und andererseits die Leitkanäle durch die Leitschaufeln miteinander verbindende Stege in Zellen unterteilt sind.The present invention relates to a guide device for axial steam or gas turbines, in which the two known devices, namely the twisting of the blades and the subdivision of the Channels are united. The invention consists in keeping blades with constant blade width on the one hand by continuously reducing the exit angle radially from the inside to the outside the guide channel cross-sections gradually in the same way remove and on the other hand connecting the guide channels through the guide vanes Ridges are divided into cells.

Während bei der Verdrehung der Schaufeln der angestrebte Zweck erst bei weitgehender Verdrehung erreicht wird, welche die Strömungsverhältnisse ungünstig beeinflußt, und andererseits durch die Unterteilung der Schaufehl der Zweck nur durch Anbringung von v,ielen Stegen zu erreichen wäre, wobei sich entsprechend viele schädliche Kantenstöße ergeben, wird durch die Vereinigung der beiden an sich bekannten Ausführungen der Vorteil erzielt, daß man schon mit einer geringen Verwindung, welche die Strömungsverhältnisse nur unwesentlich tmgünstig beeinflußt, und ebenso mit einer in geringen Grenzen gehaltenen Stegunterteilung, die ebenfalls nur kleine Stoßverluste mit sich bringt, den angestrebten Zweck erreicht. Durch die Er-While turning the blades the intended purpose only goes far Rotation is achieved, which has an unfavorable influence on the flow conditions, and on the other hand, by dividing the display, the purpose is only by attachment from v, ielen webs would be reached, with a corresponding number of damaging edge joints result, by combining the two known versions of the The advantage achieved is that even with a small amount of torsion, the flow conditions influenced only insignificantly, and also with one within small limits held web subdivision, which also brings only small shock losses with it, the intended purpose achieved. Through the

Claims

Finding the disadvantages discussed at the beginning of the fan effect, the harmful Influence of the long blades and the radial flows of the propellant within the Guide channels eliminated.

As is well known, the best efficiency is achieved when the heat gradient is proportional is the square of the peripheral speed. This requirement can be met by ίο the guide device according to the invention because the division of the heat gradient on the circumference of the wheel rim now meets this condition in any way can be customized. Turbines are known in which the guide channels are divided into two or more by webs Annular spaces are divided so that the propellant differs widely in the two annular spaces to relax. In turbines of this type, the blade angles in the two annular spaces have also been designed differently; the blades of the outer ring have been given smaller exit angles than those of the inner ring, in order to be able to process a larger amount of propellant in this. In such an arrangement, the guide vanes are probably divided into cells by webs and the exit angle variable. However, the exit angles are only with respect to each Annular space of various sizes, while within an annular space in radial Direction are unchanged. The change in the blade angle does not take place gradually as in the known embodiment in the case of the subject matter of the invention, but in sections. Such a training is the blade angle but is not suitable for the purposes of the present invention.

The drawing illustrates an embodiment of the subject matter of the invention; the Fig. Ι shows the new guide device in perspective, while Fig. 2 a section along the line I-I of Fig. 1 represents.

The guide blades s, which form the guide channel k , are fastened in a known manner by means of the blade root / in the cylinder or insert ζ; W ₁ w \ are the exit angles, v, V _{1 are} the entry angles at the points and 0 of the guide vanes s, while the outlet cross sections of the guide channels k at the points ο and u are denoted by b and α.

From Figs. 1 and 2 it can be seen that the exit angles w, W ₁ gradually decrease from the inside, u to the outside, 0 and therefore the exit cross-sections a, b also become smaller in the same radial direction; as a result, the exit velocities of the propellant in the guide channel k gradually increase from 11 to 0. At the point u , apart from other known circumstances, the angles w and the cross-sectional shape are to be selected so that the exit cross-section a at this point 11 becomes relatively large. Similar to the outlet of the guide channel, if necessary, the inlet can also be designed with inlet angles that decrease from the inside to the outside; the trailing and leading edges of the guide vane ·! can be shaped according to any spatial lines.

The guide vane channel is subdivided by the webs t into several cells k _u k ₂ , k ₃ , the webs t simultaneously to mutual. Support of the guide vane as can serve.

P Λ T Ii N T A N S F It Ü CUE:

ι. Guide device with variable angles along the blades, characterized in that that while maintaining blades with constant blade width on the one hand by steadily reducing the exit angle radially from the inside to the bottom outside the duct cross-sections gradually decrease in the same way and on the other hand, the guide channels through the guide vanes interconnecting webs are divided into cells.

2. Guide device according to claim 1, characterized in that also by stctiges Reducing the entry angle radially from the inside to the outside of the guide channel cross-sections in the same way gradually decrease.

1 sheet of drawings.