A hydraulic turbine installation and method of assembling a turbine headcover composed of two half sections in the turbine pit. The opening into the pit at the top thereof is smaller than the diameter of the headcover. Furthermore, the turbine thrust bearing flange located in the pit below the opening defines an inside diameter which is also less than the diameter of the headcover. However, diametrically opposed slots are provided in the thrust bearing flange having a span therebetween which is greater than the diameter of the headcover. This arrangement permits lowering a headcover half section with its diameter dimension disposed vertically through the top opening into the pit and then rotating the half section into the thrust bearing slots so that the diameter dimension is disposed horizontally. From this position, means are provided to rotate and lower each turbine half section onto its pit mounting.
29/428, 290/52, 415/201, 415/214.1, 415/232
The embodiments of the invention in which an
exclusive property or privilege is claimed are defined as follows
1. A hydraulic turbine generator installation comprising in combination:
2. The hydraulic turbine installation set forth in claim 1 wherein the diametrically opposed openings between said thrust collar supporting flanges are in alignment with the joint between the two half sections when they are in the assembled headcover position.
3. The method of mounting a hydraulic turbine headcover composed of two half sections into the turbine pit in a horizontal position wherein a flange provided about the pit opening has an inside diameter less than the assembled diameter of said headcover and greater than the radius thereof, each half section having diameter and radius dimensions equal to the diameter and radius of the assembled headcover, said method comprising the steps of:
This invention pertains to hydraulic turbine generators in general, and more particularly, to a structure and method for installing a turbine headcover into the turbine pit.
In vertically disposed hydraulic turbines, such as Francis turbines, the headcover of the turbine is usually substantially annular in shape and is usually the element of the turbine which is largest in diameter. The headcover is supported in the turbine pit above the runner and in turn usually supports the upper wicket gate trunnions, the turbine main guide bearing and other turbine elements.
The machine thrust bearing is usually supported on an annular flange about the interior of the pit above the headcover. Furthermore, the generator stator is usually supported on a flange provided about the top opening of the pit. In most instances, it is desirable from both a design and economic standpoint to provide the mounting flanges for both the thrust bearing and the generator stator with a smaller diameter than the diameter of the headcover. This, however, presents a serious installation problem since the headcover must be installed in the pit below the thrust bearing and generator stator flanges. This requires that the headcover pass through the openings defined by these flanges.
In the past, this size relationship problem was overcome by manufacturing the headcover in quarter sections. These sections were small enough to fit through the openings defined by the thrust bearing flange and the generator stator flange. However, handling four quarter sections of a headcover which may weigh in total in the neighborhood of 180 tons takes considerable time and requires considerable attachment problems once the quarter sections are in place. It is, therefore, more desirable, if possible, to assemble the headcover in half sections. However, half sections then create the space problem above referred to.
It is, therefore, the intention and general object of this invention to provide a hydraulic turbine installation wherein the openings through the generator stator support flange and the thrust bearing support flange can be relatively smaller than the diameter of the turbine pit and still permit assembly of the headcover in half sections.
A more specific object of the subject invention is to provide structure of the hereinbefore-described type wherein diametrically opposed slots are provided in the thrust bearing support flange which have a span therebetween equal to the diameter of the assembled headcover.
A further object of the subject invention is to provide a method of assembling the half sections of a turbine headcover of the hereinbefore-described type wherein the half sections are rotated through the slots provided in the thrust bearing support flanges to the proper headcover mounting position.
These and other objects of the subject invention will become more fully apparent as the following description is read in light of the attached drawings wherein:
FIGS. 1 through 10 show in pictoral form the structure and procedure of practicing the invention.
Referring to the drawings wherein like reference characters indicate the same elements 6 identifies the pit in which the turbine runner is located. This pit 6 is usually defined by a concrete superstructure generally indicated 7. In the normal arrangement of a vertical hydro-turbine generator or a reversible pump turbine, the turbine runner is located at the bottom portion of the pit and the generator is located above the pit.
An annular flange 8 is provided at the opening 9 to the pit 6. This annular flange 8 defines an inside diameter which is considerably smaller than the diameter of the pit 6. The generator stator (not shown) is, in most instances, supported by this annular flange. Spaced downwardly from and on the inside of the pit 6 are a plurality of annular flanges 11 which provide a support for the turbine-generator thrust bearing (not shown). It should be noted that the inside diameter defined by the thrust bearing flanges 11 is also smaller than the diameter of the pit 6 and as herein shown may be still smaller than the diameter of the generator stator mounting flange 8.
The ends of the thrust bearing flanges 11 define therebetween openings or slots 12 and 13 (best shown in FIG. 9 which is a plan view) which are diametrically opposed from one another. The span between opposite openings 12 and 13 is, in this instance, equal to the diameter of the pit 6. Two wicket gates 14 and 16 are herein schematically shown to indicate the mounting location of the turbine headcover.
The turbine headcover is composed of two half sections 17 and 18. Each half section is provided with a diameter dimension 19 and a radius dimension 21 which is equal to the diameter and radius of the asembled headcover.
The method of assembly of the headcover is depicted in the 10 figures shown in the drawings. Referring to FIG. 1, it will be seen that each half section is provided with a number of strategically located lifting points which will be described as an explanation of the method of assembly is disclosed. Two conventional hoists or cranes of sufficient capacity are required above the pit. Furthermore, an additional hoist is required from below the pit as is shown in FIGS. 5 through 7. The headcover half section 17 is connected to the hoists which for purposes of description may be referred to as the main hoist connected to cable 22 and the auxiliary hoist controlling the cable 23. The main cable 22 is connected to the lifting point 24 which is substantially at the center of the diameter dimension 19 of the headcover half section. The auxiliary cable 23 is connected to the lifting point 26 which is at one end of the half section diameter dimension 19. With this support, the half section can be pivoted so that the diameter dimension 19 is substantially vertically disposed and the radius dimension 21 is substantially horizontally disposed. In this position, the half section can be lowered through the opening 9 defined by the flange 8 and also the opening defined by the thrust bearing flanges 11. This position is shown in FIG. 1.
The headcover half section 17 is located in alignment with the diametrically opposed slots 12 and 13 between the ends of the thrust bearing flanges 11. As shown in FIG. 2, the half section 17 is rotated about the main lifting point 24 by lowering the auxiliary cable 23 until the half section 17 attains the position shown in FIG. 3. In this position, the diameter dimension 19 is in the horizontal position and the radius dimension 21 is vertically disposed. When in the position shown in FIG. 3, stationary cables 26 and 27 are connected to the half section 17 to support it while the main and auxiliary hoist connections are rearranged. Referring to FIG. 4, which is an end view of FIG. 3, the main cable 22 is now connected to a lifting point 28 on the surface 29 of the headcover at a point in alignment with substantially the midpoint of the diameter dimension 19 of the half section. The auxiliary cable 23 is connected to the lifting point 24.
Referring now to FIG. 5, a secondary hoist cable 31 is connected through a lifting point 32 provided in the superstructure 7 of the hydro installation and to a connecting point 33 on the headcover half section 17. Referring to FIG. 6, the secondary hoist is operated to swing or laterally move the half section 17 toward the lifting point 32. Simultaneous with this movement, the auxiliary hoist 23 is lowered to permit the half section to pivot about the connecting point 28 of the main cable toward the horizontal position shown in FIG. 7. When in the position shown in FIG. 7, all three hoists are lowered equally to permit the half section to be lowered onto the wicket gates 14 and onto the blocks 33 as shown in FIG. 8.
Once in the position shown in FIG. 8, the three hoists are disconnected from the half section 17 and the other half section 18 is lowered into place in the same manner as shown in FIG. 8. Once half section 18 is moved into alignment with section 17, they are rigidly connected together. The main hoist is then attached to the assembled headcover as shown in FIG. 10 and the assembled headcover is lowered into its permanent position above the turbine runner (not shown).
From the above description, it can be seen that a novel combination of structural configuration of the turbine headcover half sections and the turbine pit permit the headcover to be assembled in half sections, while, at the same time, permitting the generator stator support flange and the turbine thrust bearing support flange to define diameters smaller than the diameter of the pit. Furthermore, because of the slots 12 and 13 between the ends of the thrust bearing support flanges 11, the half sections 17 and 18 can be rotated in the manner shown in FIG. 2 with only a minimum amount of head room between the mounting position of the headcover and the top of the pit. This is particularly desirable in vertical hydro-turbine installations since each additional foot of excavation, which can be saved, results in a saving of hundreds of thousands of dollars in the cost of the installation.