JPH0640370U - Pelton turbine - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] A Pelton turbine that enables inspection of wear of nozzle tip liner and needle tip without draining running water, opening and closing manholes, and operating deflectors. provide. A bypass valve pressure distribution valve 27 for switching and supplying pressure oil for switching driving of a bypass valve servomotor 26 for controlling opening / closing of a bypass valve 25 of a water turbine and a valve mounted on a peripheral edge of a disc. A needle 12 arranged so that the flowing water introduced through the inlet valve 20 can be made to collide with a plurality of buckets and is controlled to move forward and backward by a needle servomotor 14 driven by pressure oil. In a Pelton turbine equipped with a plurality of injection pipes 10 each having a nozzle tip liner attached therein, the wear of either the needle tip or the nozzle tip liner is checked depending on the open / closed state of the bypass valve while stopped. It is characterized by detecting.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a Pelton turbine used for power generation in a hydroelectric power plant, and in particular, it is possible to detect the presence or absence of water leakage from an injection pipe from the open / closed state of a bypass valve when the turbine is stopped. It is about the Pelton turbine.

[0002]

[Prior art]

 There are several types of turbines used for power generation at hydroelectric power stations, and in order to drive the turbines in rotation, the optimum type of turbines can be introduced by taking into consideration the head and the flow rate of running water that can be introduced into the turbine. Is selected. The Pelton turbine, which is the subject of the present invention, is a turbine applied to a power plant that is usually constructed in a place where the head is relatively large and the flow rate is relatively small.

As will be described later in detail, in the Pelton turbine, high-pressure running water introduced from a water source through a water conduit and a penstock is branched into a plurality of injection pipes downstream of an inlet valve, and the tip of each injection pipe is divided. It is an impulse type water turbine that obtains a rotational force by being jetted from a cylinder and collided with a plurality of buckets evenly attached to the peripheral edge of a disk fitted to the main shaft. The flow rate of the flowing water that is jetted from the tip of the injection pipe to the bucket and is injected into the bucket is adjusted by moving the conical needle provided inside the jet forward and backward to adjust the output of the water turbine.

FIG. 4 is a partially cutaway cross-sectional view showing an example of the structure of the injection pipe, and FIGS. 5A and 5B are cross-sectional views showing details of constituent members at the tip of the injection pipe. Is. In FIG. 4, reference numeral 10 denotes an injection pipe, which is branched and curved from an inlet valve (not shown) on the right side of the drawing, has an opening at the tip, and is provided with a needle guide 11 at the center of the interior near the tip. A needle stem 11 having a needle 12 screwed into the needle guide 11 is inserted into the needle guide 11, and the needle stem 13 is provided on the curved outside of the injection pipe 10. It is connected to the motor 14. A nozzle tip liner 15 is fitted on the inner peripheral surface of the tip opening of the injection pipe 10 to prevent water leakage from the injection pipe 10 when the needle 12 shown in the drawing is fully closed.

Reference numeral 16 denotes a bucket evenly attached to the periphery of a disk 17 fitted on a main shaft of a water turbine (not shown), and constitutes a runner of the water turbine together with the main shaft and the disk. The servo motor 14 is controlled by pressure oil supplied from a pressure oil tank (not shown) via a pressure distributing valve, and moves the needle 12 forward and backward via a needle stem 13 to move the nozzle tip liner 15 and the nozzle tip liner 15 together. The gap with the needle 12 is increased or decreased to adjust the injection flow rate of the flowing water that collides with the bucket 16.

Reference numeral 18 denotes a deflector, which is rotatably supported by a shaft 181 provided at the lower end of the tip of the injection pipe 10 and is controlled to be opened and closed by an opening / closing control mechanism (not shown). The drawing shows a closed state. The deflector 18 is controlled to an open state indicated by a broken line during operation of the water turbine so that the jet injected from the tip of the injection pipe 10 does not hinder the collision with the bucket 10. It is controlled to the closed state shown by the solid line, and prevents the jet from the injection pipe 10 from colliding with the bucket 16.

In order to prevent the runner of the turbine from being accelerated and overspeeding when the generator load is cut off due to a power system accident or the like in which a generator driven by the turbine is connected, 12 must be fully closed to immediately stop the jet injection from the injection pipe 10 to prevent the jet from colliding with the bucket 16, but the servomotor which is the control mechanism of the needle 12 is required. No. 14 has no responsiveness, and the jet injection cannot be stopped by directly performing the closed control in the illustrated state. The deflector 17 is provided mainly for the purpose of preventing the turbine runner from overspeeding in the above-mentioned case, and has a control device capable of prompt response control. Closed to prevent the jet jet from colliding with the bucket 16 and prevent the turbine runner from overspeeding.

FIG. 5A is a detailed sectional view of the needle 12, and FIG. 5B is a detailed sectional view of the tip of the injection pipe 10. In FIG. 5, the needle 12 is composed of a cone-shaped needle tip 121 and a needle head 122, or both are integrated. The needle tip 121 has a female thread formed inside the center thereof and is screwed to a male thread cut at the tip of the needle stem 13 inserted into the center hole of the needle head 122. As shown in FIG. 5 (b), the nozzle chip liner 15 is fitted to the inner surface of the tip end opening of the injection pipe 10, and when the needle is fully closed, the cone of the needle dowel tip 121 shown in FIG. 5 (a). The side surface contacts this nozzle tip liner 15 to prevent water leakage from the injection pipe 10.

The high-pressure running water jet at the tip of the jet pipe 10 and the needle tip 121 are configured as described above, and the jet jet moves the needle 12 forward and backward, and the nozzle tip liner 15 and the needle tip line. Since the flow rate is adjusted by increasing or decreasing the gap between the nozzle tip liner 15 and the needle tip 121, the nozzle tip liner 15 and the needle tip 121 are the main parts for adjusting the injection flow rate. Therefore, these are the parts that are most susceptible to the influence of running water, and power plants that use river water containing large amounts of earth and sand, etc., wear down in a short period of time, their shutter surfaces are dented, and the needle 12 is completely removed. Even if they are closed, a gap will be created between them, and it will be impossible to completely stop the running water, resulting in water leakage.

As described above, the deflector 18 is controlled to be in the closed state shown in the figure while the water turbine is stopped, and even if there is running water (usually water leakage) from the injection pipe 10, it is prevented from colliding with the bucket 16. To prevent. Therefore, when a water leak occurs, the water leak hits the deflector 18 and accelerates its wear, eventually penetrates the deflector 18, and the water leak hits the bucket 16 directly, which is a very dangerous state.

Further, when the nozzle tip liner 15 and the needle tip 121 are worn and a dent is formed, the jet flow to be jetted is disturbed and becomes a turbulent flow and collides with the bucket 16. The kinetic energy of the high-speed running water is not used effectively in the bucket 16, resulting in a decrease in the operating efficiency of the water turbine.

For the reasons described above, early detection of the wear of the nozzle tip liner 15 and the needle tip 121 is a very important requirement for the operation of a hydroelectric power plant using a Pelton turbine. . However, at present, it is impossible to check the wear of the nozzle tip liner 15 and the needle tip 121 from the outside of the injection pipe 10. Therefore, the water turbine is stopped and the drainage inside the running water portion is stopped. After performing water, the manhole is opened to enter the housing, and if necessary, the nozzle tip liner 15 and the needle tip 121 can be inspected for the first time by operating the deflector 18 to the extent that they can be inspected. Therefore, it takes a considerable amount of time and labor to detect the wear of the nozzle tip liner 15 and the needle tip 121, which leads to a large decrease in operational efficiency of the hydroelectric power plant.

[0013]

[Problems to be solved by the device]

 The problem to be solved by the present invention is that the wear of the nozzle tip liner and the needle tip cannot be detected without draining the running water part of the Pelton turbine, opening and closing the manhole, and operating the deflector. It is a point. Therefore, an object of the present invention is to obtain a Pelton turbine capable of detecting the wear of the nozzle chip liner and the needle tip without draining the running water portion of the turbine, opening and closing the manhole, operating the deflector and the like. That is.

[0014]

[Means for Solving the Problems]

 The present invention, when the Pelton turbine is stopped, reduces the water pressure on the downstream side of the inlet valve caused by water leakage from the injection pipe due to wear of the nozzle tip liner, the needle tip, etc. It is detected from the state, and wear of the nozzle tip liner, needle tip, etc. is detected indirectly from the open / closed state of the bypass valve.

That is, when the hydraulic turbine is stopped, the water pressure acting on the valve body of the bypass valve that blocks the supply of the control pressure oil is utilized, and the injection pipe is formed with the sheet portion of the bypass valve valve body as the boundary line. If there is no water leakage from the bypass valve and the water pressure on the downstream side of the bypass valve is maintained, the bypass valve opens, and if the water pressure on the downstream side of the bypass valve decreases due to water leakage, the bypass valve is completely discharged. It is characterized in that it is configured to be in a closed state.

[0016]

【Example】

 Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is an oil pipe system diagram when a Pelton turbine is stopped, showing an embodiment of the present invention. In FIG. 1, reference numeral 20 denotes an inlet valve provided at the end of the penstock PS, which is controlled to be opened and closed by an inlet valve hydraulic servomotor 21, and the downstream side thereof is branched into two parts to inject the injection pipe 10 , 10 are connected. Reference numeral 25 is a bypass valve that bypasses the inlet valve 20 and is controlled to be opened and closed by a bypass valve servomotor 26.

On the other hand, pressure oil is supplied to the inlet valve servo motor 21 and the bypass valve servo motor 26, which control the opening and closing of the inlet valve 20 and the bypass valve 25, respectively, through the following routes. That is, from the hydraulic oil tank 30, through the pipe 31, the hydraulic pressure blocking valve pressure distribution valve 32, the opening side oil supply pipe 33 of the hydraulic pressure blocking valve pressure distribution valve 32, the hydraulic pressure blocking valve 34, and the pipe 35, the inlet valve pressure distribution valve 22 and the bypass valve pressure distribution valve. It is supplied to the closed side oil supply pipes 23, 28 or the open side oil supply pipes 24, 29 of the corresponding servo motors 21, 26 by operating the pressure distributing valves 22, 27. Incidentally, 36 is a closing side oil supply pipe of the hydraulic pressure blocking valve 34.

FIG. 2 is a vertical sectional view of the bypass valve hydraulic servo motor 26 when the bypass valve 25, which bypasses the inlet valve, is fully closed. In the figure, arrows A and B indicate the water flow directions of the introduced water introduced to bypass the inlet valve 20. Reference numeral 25a is a valve body, and 25b is a valve body provided in the valve body 25a, which is connected to a piston 26a of a hydraulic servo motor 26 mounted on the right side of the drawing via a rod 26b. Reference numeral 25c is a bush attached to the inner surface of the valve body 25a on the inlet side of the inlet water, and 25d is in contact with the right end of the bush 25c when the valve body 25b is in the fully closed position as shown in the drawing. It is a sheet surface that seals the sides. The bypass valve 25 is fully closed as shown when the above-mentioned pressure oil is supplied to the closed side oil supply pipe 28 of the hydraulic servo motor 26, and is fully opened when supplied to the open side oil supply pipe 29. To do.

Next, the operation of the present invention constructed as above will be described. As described above, since FIG. 1 shows an oil pipe system diagram when the Pelton turbine is stopped, the pressure oil blocking valve and the pressure distribution valve 32 are controlled to the closed side, and the pressure oil from the pressure oil tank 30 is piped. It is supplied to the closed side oil supply pipe 36 of the pressure distribution valve 32 through 31, and the pressure oil blocking valve 34 is fully closed. Therefore, the hydraulic pressures of the closing side oil supply pipes 23, 28 of the servo motors 21, 26 of the inlet valve 20 and the bypass valve 25 are zero.

The stopping operation of the generator driven by the Pelton turbine is usually: generator load-generator no load-generator disconnection-generator excitation cutoff-turbine needle closing-turbine deflector closing-inlet valve closing. -The bypass valve is closed. Therefore, when the Pelton turbine is stopped, all the water channels on the upstream side, including the injection pipe 10, are filled with the introduced water.

As described above, when the water turbine is stopped (in FIG. 2), the inside of the bypass valve valve body 25a is filled with the introduced water, so if there is no water leakage from the tip of the injection pipe 10, the bypass valve The water pressure P per unit area due to the introduced water in the valve body 25a is equal on the upstream side and the downstream side of the valve body 25b. Therefore, with the sheet surface 25d as a boundary, the downstream side introduced water pressure F1 acts from the left side and the upstream side introduced water pressure F2 acts from the right side on the bypass valve body 25b as shown in the figure. become. Since the introduction water pressure acting on the bypass valve body 25b is P, the downstream introduction water pressure F1 and the upstream introduction water pressure F2 are respectively F1 = π / 4 × D1 · D1 · P F2 = π / 4 * (D2-D3) * (D2-D3) * P, and the bypass valve 25 is usually designed so that F1> F2. As described above, when the turbine is stopped, the hydraulic pressures of the closed side oil supply pipes 23, 28 of the servo motors 21, 26 of the inlet valve 20 and the side valve 25 are 0, so The open / closed state of the valve element 25b of the valve 25 is determined by the magnitude of the downstream side introduced water pressure F1 and the upstream side introduced water pressure F2.

That is, when there is no dent or gap due to wear on the shutter surface of the needle tip 121 or the nozzle tip liner 15 and no water leakage occurs, the relationship of F 1> F 2 as designed is maintained. To be done. Therefore, the bypass valve valve body 25b is pushed rightward in the drawing by the downstream side introduced water pressure F1 to be opened, and this state is maintained.

Further, in the case where the shutter surfaces of the needle tip 121 and the nozzle tip liner 15 have dents and gaps due to wear and water leakage has occurred, the downstream side introduced water pressure F1 gradually decreases. , F1> F2 is no longer established, and finally F1 <F 2, and the bypass valve body 25b is opened by the upstream side introduced water pressure F2 even if it is temporarily opened after the turbine is stopped. It will be pushed to the left and will eventually remain closed.

As described above, the open / closed state of the bypass valve 25 after the turbine is stopped is determined by the magnitude of the downstream side introduced water pressure F1 and the upstream side introduced water pressure F2, and both water pressure forces F1 and F2. The size of is determined by the water leakage from the shutter surface of the needle tip 121 and the nozzle tip liner 15. Therefore, check the open / closed state of the bypass valve 25 when a predetermined time has elapsed after the turbine was stopped. Thus, it is possible to indirectly detect the presence or absence of water leakage in the injection pipe 10.

FIG. 3 is a graph showing the relationship between the downstream side introduced water pressure and the degree of wear of the shutter surface of the needle tip or nozzle tip liner with respect to the elapsed time after the turbine is stopped. On the other hand, the larger the degree of wear of the shutter surface of the needle tip or nozzle tip liner, the greater the amount of water leakage, and the greater the change in the downstream water pressure.

[0026]

[Effect of device]

 Although the present invention has been described in detail above, according to the present invention, water leakage from the injection pipe (wear of the needle tip or the shutter surface of the nozzle chip liner due to the open / closed state of the bypass valve when the water turbine is stopped). ) Can be detected, it is safe to detect water leaks, and to check for wear, stop the turbine, drain water in the running water section, open and close the manhole, operate the deflector as necessary, etc. Since no work is required, the operation efficiency of the hydropower plant will be improved, and the time and labor of maintenance personnel can be reduced.

[Brief description of drawings]

FIG. 1 is an oil pipe system diagram when a Pelton turbine is stopped, showing an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a bypass valve (when fully closed) and a bypass valve hydraulic servo motor.

FIG. 3 is a graph showing the relationship between the downstream side introduced water pressure and the degree of wear of the shutter surface of the needle tip or nozzle tip liner with respect to the elapsed time after the turbine is stopped.

FIG. 4 is a partially cutaway sectional view showing an example of the configuration of an injection pipe.

5 (a) and 5 (b) are sectional views showing details of constituent members at the tip of the injection pipe.

[Explanation of symbols]

 10 ... Injection pipe, 12 ... Needle, 121 ... Needle tip, 14 ... Needle servo motor, 15 ... Nozzle tip liner, 16 ... Bucket, 17 ... Disk, 20 ... … Inlet valve, 21 …… Inlet valve servo motor, 22 …… Inlet valve pressure distribution valve, 25 …… Sideway valve, 26 …… Sideway valve servomotor, 27 …… Sideway valve pressure distribution valve , 30 ... Pressure oil tank, 34 ... Pressure oil blocking valve.

Claims (1)

[Scope of utility model registration request] 1. An inlet valve servomotor that supplies pressure oil from a pressure oil tank through a pressure oil blocking valve that is fully closed while the turbine is stopped, and that controls the opening and closing of the inlet valve of the turbine. The pressure oil is supplied through the inlet valve pressure distributing valve for switching and supplying the pressure oil to be switched to the inlet valve servo motor and the pressure oil blocking valve to control the opening / closing of the bypass valve of the water turbine. The bypass valve distributing valve for supplying the pressure oil for switching and driving the bypass valve servomotor to the bypass valve servomotor and the peripheral edge of the disk fitted to the main shaft of the water turbine. A nidder servo-bomo, which is arranged at a position where the flowing water introduced through the inlet valve can collide with a plurality of attached buckets and which is driven by the pressure oil.
A Pelton turbine having a plurality of injection pipes having a nozzle tip liner mounted on the inner peripheral surface of the tip of the needle, the inside of which is provided with a needle tip attached to the tip thereof and which is controlled to move forward and backward. A Pelton turbine that detects wear of at least one of the needle tip and the nozzle tip liner based on an open / closed state of the bypass valve while the turbine is stopped.