JPH0335511B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a suction pipe for a reaction water turbine such as a Francis, Kaplan or Chupe water turbine.

``Prior Art'' Conventionally, the diameter of the suction pipe of a reaction turbine such as a Francis, Kaplan, or Chupe turbine is larger on the outlet side that opens to a spillway than on the inlet side that is connected to the water turbine. For this reason, when swirling water flows into the suction pipe from the runner of the water turbine, this swirling flow further develops in the suction pipe, and the swirling velocity component does not recover pressure and becomes a head loss, which has a large impact on the performance of the water turbine. There were flaws. In addition, in cases where a center pier is formed in the suction pipe for reasons of strength or gate manufacturing, the waterway of the suction pipe is partitioned into multiple waterways by the center pier, so each waterway is divided by the swirling flow. There is a drawback that drifting current exists in the waterway up to the outlet of the suction pipe, degrading the performance of the water turbine.

"Problems to be Solved by the Present Invention" In view of the above-mentioned conventional drawbacks, the present invention suppresses the development of swirling flow flowing into the suction pipe from the runner of the water turbine over the entire diameter of the suction pipe. An object of the present invention is to obtain a suction pipe for a reaction water turbine which can rectify the swirling flow and prevent the performance of the water turbine from deteriorating.

"Means for Solving the Problems" The suction pipe of the reaction water turbine of the present invention is provided with at least one straightening blade whose height spans the entire length of the diameter in a portion of the suction pipe where the flow velocity is relatively low. Even if a swirling flow flows in from the runner, the development of the swirling flow can be suppressed and the swirling flow can be rectified.

"Function" Even if a swirling flow flows in from the reaction turbine of a water turbine, the kinetic energy of the swirling flow existing upstream of the straightening blade is transferred to the back of the straightening blade whose height spans the entire diameter of the blade without increasing friction loss. Since it is converted into pressure energy in the suction pipe on the upstream side, swirling flow is suppressed in the suction pipe and flows in a rectified state.

"Embodiments of the present invention" The present invention will be described in detail below with reference to embodiments shown in the drawings.

1 to 3 show embodiments of the present invention. In the figures, 1 indicates a space between the water turbine 2 and the waterway 4, which discharges water flowing out from the runner 3 of the waterwheel 2 into the waterway 4. This suction pipe has an outlet greatly enlarged in diameter with respect to an inlet which is connected and bent at approximately 90 degrees, and this suction pipe 1 has an inlet having a circular shape and an outlet having a rectangular shape. In the embodiment of the present invention, the diameter of the suction pipe 1 extends over the entire length in the water flow direction in the suction pipe 1, and in the embodiment of the present invention, a single streamlined rectifying blade is formed with a thin rear part. is the length Y with respect to the thickness X of the straightening blade 5, 3・X≦Y
It is formed to have a size of ≦6·X. Further, the installation position of the straightening blade 5 is such that the distance from the center line of the main shaft 6 of the water turbine 2 to the tip of the straightening blade 5 is L, and from the outlet end surface 7 of the suction pipe 1 to the rear end of the straightening blade 5. The distance between L and M is 2・D≦L≦ with respect to the inlet diameter D of the suction pipe 1.
4.D The rectifying blade 5 is installed at a position where M≧0.5D. Reference numeral 8 denotes a gate globe for a gate that opens and closes the water channel in the suction pipe 1, and this gate globe 8 is formed in a direction perpendicular to the side inner wall of the suction pipe 1 and the side wall of the rectifying blade 5.

In the case of the suction pipe 1 of the reaction water turbine having the above configuration,
When the swirling flow that enters the water turbine 2 from the penstock 9 and flows out while rotating the runner 3 flows into the suction pipe 1 and passes through, the swirling flow is transferred to the suction pipe formed in the suction pipe 1. The flow water is divided into two water channels by a straightening blade 5 extending over the entire length of the diameter of 1, suppressing the development of swirling flow, and rectifying the water flow. Water is discharged to the spillway 4. The suction pipe 1 has a gate (not shown) fitted into a gate globe 8 formed on the inner wall of the suction pipe 1 and the side wall of the straightening blade 5 so that the water passage of the suction pipe 1 can be opened and closed.

Next, different embodiments of the present invention shown in FIGS. 4 and 5 will be described. In the description of these embodiments, the same components as those of the embodiments of the present invention are designated by the same reference numerals and redundant explanations will be omitted.

The main difference between the embodiments shown in FIGS. 4 and 5 from the embodiment of the present invention is that the suction pipe 1 is a straight suction pipe 1A; The distance from the inlet end face 10 to the tip of the straightening blade 5 is defined as L.

Similar effects can be obtained with the suction pipe 1A configured in this manner.

"Effects of the Present Invention" As is clear from the above description, the present invention has the following effects.

(1) Since at least one or more straightening vanes are provided that span the entire diameter of the suction pipe and are capable of suppressing the development of swirling flow into the suction pipe and rectifying the swirling flow, the reaction flow into the suction pipe is Even if a swirling flow flows in from the runner of the water turbine at the center or the outer periphery, the development of the swirling flow can be suppressed and the flow can be rectified. Therefore, it is possible to improve the pressure recovery rate in the suction pipe, and to prevent the performance efficiency of the water turbine from decreasing.

(2) Since the development of swirling flow can be suppressed and the current can be rectified, vibrations of the water turbine can be suppressed. Therefore, the strength of parts, supporting members, etc. of the water turbine can be reduced.

(3) Since the suction pipe is equipped with a rectifying blade, the suction pipe can be reinforced. Therefore,
There is no need to newly provide reinforcing ribs, etc.

(4) Since it is only necessary to provide a rectifying blade in the suction pipe, the structure is simple and can be manufactured at low cost.

(5) The straightening vanes are extended to the hand of the outlet end, so that the flowing water near the outlet of the suction pipe is once divided into multiple flow channels and then merged into one flow channel again, so that pressure recovery inside the pipe ( A phenomenon in which the pressure distribution becomes uniform over the entire cross section of the pipe occurs, and the pressure of the flowing water inside the pipe becomes uniform, making it possible to increase the efficiency of the water turbine.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the state of use of the present invention;
3 is a side view showing one embodiment of the present invention, FIG. 3 is a plan view of FIG. 2, FIG. 4 is a side view showing a different embodiment of the invention, and FIG. 5 is a plan view of FIG. 4. be. 1, 1A: Suction pipe, 2: Water wheel, 3: Runner,
4: Discharge channel, 5: Rectifying blade, 6: Main shaft, 7: Outlet end face, 8: Gate globe, 9: Penstock pipe, 10: Inlet end face.

Claims (1)

[Scope of Claims] 1. A rectifier vane is provided near the outlet of the suction pipe of the reaction water turbine, partially spanning the entire diameter of the suction pipe and extending to the front of the outlet end, and near the exit of the suction pipe. A suction pipe for a reaction water turbine, characterized in that flowing water is once divided into a plurality of flow paths and then merged into one flow path again. 2. In the suction pipe of the reaction turbine as set forth in claim 1, the installation position of the straightening blade on the suction pipe is, in the case of a bent suction pipe, the distance from the tip position of the straightening blade to the center of the main axis of the water turbine; Alternatively, in the case of a straight suction pipe, if the distance from the tip of the straightening pipe to the inlet end face of the suction pipe is L, then the tip position of the straightening blade is 2·D with respect to the inlet diameter D of the suction pipe. The rear end of the straightening blade was placed at a position such that ≦L≦4・D, and the distance M from the outlet end face of the suction pipe to the rear end of the straightening blade was M≧0.5D. A suction pipe for a reaction water turbine characterized by the following.