JPS60249671A - Dual pelton wheel and operating method thereof - Google Patents

Abstract

PURPOSE:To make highly efficient operation performable within a wide output range so well, by letting each bucket in plural runners differ in width, in case of a turbine which tightly installs these plural runners, attaching plural pieces of buckets to the circumference, on the same main shaft. CONSTITUTION:Two-stage runners 2 and 3 are attached to a main shaft 1 top and bottom at a proper interval, while a lot of buckets 4 and 5 are attached to each periphery of these runners 2 and 3. In addition, at the side wall of a housing 6, there are provided with nozzle pipes 7 and 8 at a position corresponding to each of these buckets 4 and 5, and each of these nozzle pipes 7 and 8 is interconnected to high pressure water inside an iron pipe via casings 9 and 10, while each of flow regulating valves 11 and 12 is installed in their tip ends. In this case, pitch circles D1 and D2 of these runners 2 and 3 are made into the same diameter and on the other hand, width (diameter) B1 of the bucket 4 is set to be larger than that B2 of the bucket 5. And, according to a turbine output value prescribed, each of these runners 2 and 3 is driven selectively or at the same time.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a double-wheeled Pelton water turbine in which a plurality of stages of launches are mounted on the same main shaft. This invention relates to different types of Perth turbines and their operating methods.

[Technical background of the invention and its problems]

In general, the turbine output characteristics of a Pelton turbine are such that when the rotational speed of the main engine is constant, the efficiency decreases as the turbine output decreases, as shown in FIG. 2, due to hydraulic power loss due to interference between the runner packet and the water jet.

In multi-nozzle Pelton turbines, in which multiple nozzles are arranged toward a single stage runner, when the turbine is operated in a low output range, it is possible to prevent a decrease in efficiency by reducing the number of operating nozzles. In places where the output of the water turbine is quite small, one nozzle operation is required, and the fluid force applied to the runner packet becomes unbalanced, putting a heavy burden on bearings and the like.

In this way, with conventional Pelton turbines, if the turbine output deviates from the standard set value, the efficiency will drop significantly and it will be difficult to continue the turbine operation due to the action of fluid unbalanced forces. It was necessary to limit the area, and it was impossible for the power plant to sufficiently respond to a wide range of operations from the power system.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances in the backing technology, and an object of the present invention is to provide a double-wheeled Pelton water turbine and a method of operating the same that can be operated with high efficiency within a wide output range.

[Summary of the invention]

In order to achieve the above object, the present invention is a double-wheeled Pelton water turbine in which a plurality of stages of launches are fixed to the same main shaft, and is characterized in that the packet widths of the plurality of runners are made different. Furthermore, in the method according to the present invention, when the required water turbine output value is smaller than the reference water turbine output, the flow rate adjustment valve of the ripple section corresponding to the runner with the smaller packet width is controlled to an appropriate opening degree, and the remaining nozzle sections are controlled to an appropriate opening degree. When the required water turbine output value is larger than the reference water turbine output, the flow regulating valves of the nozzle portions corresponding to the runner with a large packet width and the launch with a small packet width are simultaneously controlled in opening. This is a characteristic feature.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail with reference to the drawings.

Figure 1 schematically shows an example in which the present invention is applied to a vertical shaft two-stage Pelton water turbine, in which two stages of runners 2 and 3 are attached to the main shaft 1 at appropriate intervals in the vertical direction. There is. A large number of packets 4.5 are attached around each runner 2, 3, and the pitch circle B2 of each launch 2.3 is the same diameter, and the width (diameter) of the packet 4 of the upper runner 2 is )
B1 is set to be larger than the packet 50 width B2 of the lower runner 3.

A nozzle pipe 7.8 is arranged on the side wall of the housing 6 which houses the runners 2, 3 and the packets 4.5 at a position corresponding to each packet 4.5. These nozzle pipes communicate with high pressure water in iron pipes (not shown) via casings 9 and 10, and needle valves 11.12 are provided at the tips of each nozzle pipes 7.8 as flow rate regulating valves. It is being

A needle valve drive device 13.14 is connected to each needle valve 11.12 as shown in FIG. Ru. That is, the required water turbine output value P output from the water turbine output setting device 16 is determined by the determiner 17 to be the reference water turbine output P. When the relationship P≧Po exists, the needle valve drive device 13.14 is compared with the needle valve 11.12.
The opening is controlled to an appropriate opening. Further, when the relationship P<Po exists, the needle valve drive device 13 fully closes the needle valve 11, and the needle valve drive device 14 controls the opening degree of the needle valve 12 to an appropriate opening degree.

Next, the effects of the present invention will be explained.

As shown in Fig. 4, the hydraulic characteristics of a Pelton turbine are as follows: when only runner 2 with a large packet width is attached to the main shaft, and when only runner 3 with a smaller packet width is attached to the main shaft, as shown in Fig. 4, Runner 3 has higher efficiency on the lower output side than the output Po, and runner 2 has higher efficiency on the higher output side than Po.

In the water turbine of the present invention in which runners 2 and 3 having such output characteristics are attached to the same main shaft, when both runners are driven simultaneously, the reference water turbine output P. On the lower output side, the curve (2+
As shown in 3), the efficiency is lower than that when runner 2 and runner 3 are operated alone, but on the higher output side than Po, when both runners are driven simultaneously, the efficiency is lower than when runner 2. The efficiency is higher than when the runner 3 is operated alone.

The present invention skillfully utilizes this phenomenon, and the reference water turbine output P. If the required water turbine output value P is lower than
Jet water is jetted out from the nozzle pipes 7 and 8, and when the required water turbine output value P moves to a higher output side than the standard water turbine output Po, the needle valves 11 and 12 are opened to an appropriate opening degree, and the packet 4°5 is released from the nozzle pipes 7 and 8. A jet of water is ejected at the same time.

In this way, in the present invention, the packet widths of the multiple stages of runners attached to the same main shaft are made to differ, and these are driven selectively or simultaneously according to the required output value of the water turbine, so that the efficiency of the water turbine can be maintained at all times. can be kept at a high value.

In addition, in the above explanation, an example was described in which the upper and lower runners are arranged in parallel in the horizontal direction, but in order to reduce water splash interference as much as possible during lunch operation, the fifth runner is arranged horizontally in parallel.
As shown in the figures and FIG. 6, the packet mounting disks of the runners 2 and 3 may be mounted at an angle with respect to the main axis to increase the distance between the packets.

Further, in the above explanation, a Pelton turbine equipped with a two-stage runner has been described, but the present invention is not limited to this. For example, if it is desired to design a wider range of operating head, the flowchart shown in FIG. As shown, one or more runners 18 may be arranged below the second runner 3. In this case, it is desirable that the diameter B3 of the packet 19 attached to the runner 18 be smaller than that of the packet 5.

Furthermore, the present invention can be applied to Pelton water turbines other than the vertical shaft type.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to safely control the operation of a Pelton water turbine with high efficiency over a wide output range, and it is possible to significantly improve the operating range of a power plant.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view schematically showing an embodiment of the Pelton turbine of the present invention, and Fig. 2 is the output of a conventional single-wheel Pelton turbine.
Graph illustrating efficiency characteristics, FIG. 3 is a block diagram illustrating the operation control method of the present invention, FIG. 4 is a graph illustrating output-efficiency characteristics in an embodiment of the present invention, and FIGS. 5 to 7 are respectively FIG. 6 is a vertical cross-sectional view schematically showing another embodiment of the present invention. 1...Main shaft, 2...Upper runner, 3...Lower runner, 4.5.19...Packet, 6...Housing, 7°8...Nozzle pipe, 9.10... ·casing. Applicant's agent Kiyomi Inomata 1 ni 62 Prisoner Ipman Kerr 64 Figure Δ(-1! Inu Kerr right 5 Hara 6 Hara 7 Figure

Claims (1)

[Claims] 1. A plurality of runners each having a large number of packets attached to the outer periphery are fixed on the same main shaft, and a nozzle pipe equipped with a flow rate regulating valve is provided at a position corresponding to the bucket 1 of each runner. A double-wheel Pelton water turbine is characterized in that the packet widths of a plurality of runners are made different in the arranged double-wheel Pelton water turbine. 2. The double-wheeled Pelton water turbine according to claim 1, wherein the diameters of the pitch circles of each lunch packet are set equal. 3. A double-wheeled pel according to claim 1, characterized in that a launch with a large packet width is arranged in the upper stage of the same vertical main shaft, and a launch with a small packet width is arranged in the lower stage. Water wheel. 4. Attach the packets so that the distance between packets in adjacent stages is large, so that the disc is relative to the main shaft.5. If the required water turbine output value is smaller than the standard water turbine output, install the nozzle that corresponds to the runner with the smaller packet width. The flow rate adjustment valves of the pipes are controlled to appropriate opening degrees, and the flow rate adjustment valves of the remaining nozzle pipes are fully opened, and when the required water turbine output value is larger than the reference water turbine output, the runner with a large packet width and the bucket 1 are ~A method for operating a double-wheeled Pelton water turbine characterized by simultaneously controlling the opening of flow rate regulating valves of nozzle pipes corresponding to narrow runners.