JPH061779U - Pelton turbine injection device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent wear of the needle and needle tip liner due to sediment in the water flow, and to prevent water leakage from the gap between the needle tip liner and the injection port. A ceramic member is adhered to the surface of the needle, a ceramic member is adhered to the edge of the needle tip liner, and a cushioning member is inserted between the injection holes into which the needle tip liner is inserted.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a nozzle device for a Pelton turbine that copes with wear caused by sediment mixed in a water stream.

[0002]

[Prior art]

 In general, the nozzle device of a Pelton turbine is equipped with a needle-type head that controls the amount of water flowing into the turbine and prevents the water flow from scattering.

FIG. 3 is an example showing a nozzle of a Pelton turbine. A water jet 1 has a needle guide 2, a needle stem 3 and a needle 4 incorporated therein. Further, a servo motor 5 is attached to the needle stem 3, and the driving force of the servo motor 5 causes the needle 4 to move forward and backward from the nozzle tip liner 6, whereby the water flow whose flow rate has been adjusted from the injection port 8 is directed to the bucket 7. To be given.

FIG. 4 shows a partial enlargement of the injection port portion 8. The needle 4 that advances and retracts from the nozzle tip liner 6 is, as shown in the figure, a curved line-shaped integrally formed liner. It is a 13Cr stainless cast steel or a forged product, or a carbon steel cast steel or a forged product provided with a portion 4a and a head portion 4b.

[0005]

[Problems to be solved by the device]

 However, in recent years, from the viewpoint of effective use of energy, in hydroelectric power plants, in order to reduce the amount of flood water in dams or river water, relaxation or abolition of water intake restrictions at the time of river water pollution, shortening of the overhaul suspension period, Alternatively, various measures have been taken, such as extending the overhaul cycle period. In particular, the overhaul cycle period of a hydroelectric power plant is typically about 10 years, but the earth and sand abrasion has a large effect on it, and even the safety of the machine itself may be impaired during the standard period. As a result, the efficiency of the machine is reduced and the overhaul cycle period is shortened, which is an important factor.

[0006] On the other hand, the state of rivers has been deteriorating due to the development of the basin, urbanization, or the reduction of forests, and the amount of inflowing sand and sand is increasing. Is also increasing, and the life is becoming shorter.

Sediment wear of water turbine parts has been a concern since the birth of hydroelectric generators in the early Showa era, and especially in recent years, under the above circumstances, water intake restrictions, sand basins, and shortening of overhaul periods. Or, upgrading conventional materials (carbon steel to stainless steel) is not enough, and more aggressive measures are desired.

These parts made of 13 cr stainless cast steel product, cast product, carbon steel cast product, and forged product have a flow velocity around the needle in a power plant using river water containing a large amount of earth and sand. However, the wear of the needle and nozzle tip liner is dented and a gap is created within a short period of time, making it impossible to stop running water even when the needle is fully closed. Become. In addition, turbulence occurs in the jet flow that is jetted due to the occurrence of dents due to wear, and the motion energy of high-speed running water does not act effectively on the bucket, resulting in a drop in operational efficiency.

When such a state is reached, it is necessary to stop the hydroelectric power plant and replace it with a new one even in a short cycle, which causes a large decrease in power generation efficiency. It has drawbacks. In view of the above background, the present invention aims to disclose a nozzle device for a Pelton turbine that has been improved so as to maximize the life of the water jet part caused by sediment wear.

[0010]

[Means for Solving the Problems]

 According to a first configuration of the present invention, a water jet nozzle facing a bucket is provided with an injection port at its tip, and a needle tip liner is inserted into the outlet of this injection port, while a Pelton equipped with a needle that can be moved back and forth from a needle chip liner. The water jet nozzle device is characterized in that a ceramic member is attached to the surface of the needle.

The second structure according to the present invention is provided with a nozzle at the tip of the water jet nozzle facing the bucket, and a needle tip liner is inserted into the outlet of the nozzle while the needle tip liner is movable back and forth. In the injection device of a Pelton turbine equipped with such a needle, a ceramic member is attached to the edge of the needle tip liner, while a cushioning member is inserted between the injection holes into which the needle tip liner is inserted.

[0012]

[Action]

 According to the first configuration, when the needle moves forward and backward, if the earth and sand adhere to the needle tip liner, the needle causes a galling phenomenon and wears. Therefore, the wear can be prevented by depositing the ceramics on the surface of the needle.

According to the second configuration, the needle tip liner inserted into the nozzle portion is worn by dirt and the like as a result of long-term use, and water leaks from the site. For this reason, it is possible to prevent water leakage by mounting a cushioning material in the gap between the needle tip liner and the nozzle portion.

[0014]

【Example】

 Hereinafter, an embodiment of a jet nozzle device for a Pelton turbine according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing a first configuration of a nozzle device of a Pelton turbine according to the present invention.

The liner portion 4a of the needle 4 made of 13Cr stainless cast steel or the same forged product or carbon steel cast steel product or forged product is coated with a separately molded ceramic part 4c. At the time of deposition, an adhesive is applied to the inner surface of the ceramic member 4c to be machined, and the ceramic member 4c is aligned so as not to create a gap between the two to form a single-body structure. In this case, an air hole 4d is preliminarily formed in the liner portion 4a of the needle 4 for the purpose of inserting the needle 4 so that no gap is formed between them. That is, it is intended to release the pressing force of the ceramic member 4c adhered to the liner portion 4a through the air holes 4d, thereby increasing the adhesive force. FIG. 2 is a schematic view showing a second configuration of the injection nozzle device of the Pelton turbine according to the present invention.

The needle tip liner 6 is fitted into the outlet of the injection port portion 8, and the edge 6 a of the needle chip liner 6 is covered with a ceramic member 6 b. This ceramic member 6b is separately molded in advance as in the above-described first structure, and has an integrally bonded structure with an adhesive when it is attached to the edge 6a.

When the needle tip liner 6 formed in this way is fitted into the outlet of the injection port portion 8, as shown in the figure, a cushioning member 6c is inserted. This is to prevent the needle tip liner 6 from being worn due to soil or the like in the water stream and leaking water from the gap with the nozzle portion 8. By the way, when ceramics are applied to this kind of field, it is necessary to take measures against shock shock.

As a countermeasure against this, one is to slowly reduce the driving force of the servo motor 5 when the needle 4 approaches the needle tip liner 6. By doing this, the impact / buffering effect on the ceramics is weakened. The other one can utilize the above-described cushioning member 6c interposed between the needle tip liner 6 and the injection port portion 8. That is, when the needle 4 is rapidly closed toward the needle tip liner 6, the impact / buffering force is naturally generated, but the impact / buffering force can be absorbed by the buffer member 6c. Therefore, as shown in Table 1, even if the fracture toughness value of ceramics is inferior to that of metal, it can be sufficiently covered by the cushioning member 6c.

[0019]

[Table 1]

For reference, comparing the wear rates of the ceramic and the metal with reference to FIG. 5, the ceramic has a much lower value than the metal. Therefore, even if ceramics are applied to this kind of field, there is almost no risk of wear.

[0021]

[Effect of device]

 As described above, the nozzle device of the Pelton turbine according to the present invention has the needle coated with the ceramic member, so that it can be used longer than before even if it receives sediment of the water stream. In addition, while the ceramic material is applied to the edge of the needle tip liner, while a cushioning member is inserted between the needle tip liner and the injection port, it is possible to prevent not only wear and tear due to earth and sand but also water leakage. it can.

[Brief description of drawings]

FIG. 1 is a schematic view of a needle according to the present invention.

FIG. 2 is a half schematic cross-sectional view in which the needle tip liner according to the present invention is fitted and inserted in a nozzle portion.

FIG. 3 is a schematic assembly view showing a conventional embodiment.

FIG. 4 is a view showing a part of the behavior of a needle incorporated in a nozzle portion.

FIG. 5 is a graph comparing wear rates of ceramics and metals.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Water jet pipe 2 ... Needle guide 3 ... Needle stem 4 ... Needle 4a ... Liner part 4c ... Ceramic material 4d ... Air hole 6 ... Needle tip liner 6a ... Edge 6b ... Ceramic member 6c ... Buffer member 8 ... Jet part

Claims (2)

[Scope of utility model registration request] 1. A jet nozzle device for a Pelton turbine having a jet nozzle at the tip of a water jet pipe facing a bucket, and a needle tip liner fitted and inserted at the outlet of the jet nozzle, while having a needle that can advance and retract from the needle tip liner. 2. A spraying device for a Pelton turbine, wherein a ceramic member is adhered to the surface of the needle. 2. A jet nozzle device for a Pelton turbine having a jet nozzle at a tip of a water jet pipe facing a bucket, a needle tip liner fitted at an outlet of the jet nozzle, and a needle capable of advancing and retracting from the needle tip liner. 2. A nozzle device for a Pelton turbine, wherein a ceramic member is attached to the edge of the needle tip liner, and a cushioning member is inserted between the nozzle holes into which the needle tip liner is fitted.