JPH044471B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for controlling the operation of a multi-nozzle Pelton water turbine, and particularly to a method for starting a multi-nozzle Pelton water turbine when starting up and transitioning to load operation.

[Technical background and problems of the invention]

In general, the starting method for a Pelton turbine with one nozzle is to transmit a control signal for the rotational speed of the turbine to the needle valve of this nozzle via a governor, control the opening of the needle valve, and control the turbine to a synchronous speed. There is. Also, in this case, open the needle valve and
A method has been proposed in which the rotational speed of the waterwheel is made higher than the synchronous speed, the water flow is interrupted by a deflector, and then the rotational speed of the waterwheel is controlled to the synchronous speed.

In addition, as needle and deflector control devices, each needle body has a built-in servo motor and a cam is used to follow the deflector servo and needle servo piston, and a Z nozzle Pelton water turbine has two sets of cams. There are proposals for control devices such as those that set the needle opening.

By the way, multi-nozzle Pelton turbines have been developed as the capacity of hydroelectric power plants increases, but when starting up this type of Pelton turbine, it can usually be carried out in the same manner as the one-nozzle type. In this case, the needles of the other nozzles remain closed, and when a load is applied after the water turbine rotational speed is synchronized, it takes a long time to increase the load due to the time required to operate each needle. Although there have been proposals for control devices for the needles and deflectors of multi-nozzle Pelton turbines, there have been no proposals yet for a quick startup method for starting Pelton turbines to take on a load.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for starting a multi-nozzle Pelton water turbine that can reliably start the turbine and take the load quickly by controlling needles and deflectors when the multi-nozzle Pelton water turbine is started and operated under load. It's about doing.

[Summary of the invention]

In order to achieve the above object, the present invention has a bucket that rotates in response to a water flow, and a plurality of nozzles arranged on the outer periphery of the bucket. When transitioning from startup to load operation in a multi-nozzle Pelton water turbine equipped with a needle valve and a deflector attached to the tip of the nozzle pipe,
First, the water turbine is started by slightly opening the needle valve of a given nozzle with the deflector open, and the water turbine is accelerated by slightly opening the needle valve of the other nozzle, and then the water turbine rotation speed is specified to be lower than the synchronous rated speed. When the value is reached, the opening of the needle valve of the predetermined nozzle is controlled according to the change in the rotational speed of the water turbine, and the water flow ejected from the other nozzles is cut off by a deflector, and then the water turbine is synchronously set to the rated speed. When the nozzle is controlled, the deflectors of the other nozzles are opened and the needle valves of each of the nozzles are opened to shift to load operation. It is possible to shift to load operation.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for starting a multi-nozzle Pelton water turbine according to the present invention will be described using a four-nozzle Pelton water turbine as an example with reference to the drawings.

In the four-nozzle Pelton turbine shown in Figure 1,
A plurality of buckets 2 are installed in the center of the housing 1 to rotate in response to water flow, and servo motors 15, 16,
A needle valve 7 whose opening and closing are controlled by 17 and 18,
8, 9, 10 are built-in, and nozzle pipes 3,
Water flow and disconnection deflectors 11, 12, 13, and 14, which are controlled to open and close by a deflector operating device (not shown), are attached to the tips of the deflectors 4, 5, and 6, respectively.

Next, an embodiment will be described in which the starting method according to the present invention is applied to the above-mentioned four-nozzle Pelton water turbine.

As shown in the time diagram shown in Figure 2, when a Pelton turbine startup command is given, first the needle valve 7 is opened slightly to start and rotate the turbine, and at the same time or immediately after that, the remaining needle valves are opened. 8,9,1
0 is also slightly opened to accelerate the water wheel. When the water turbine rotation speed reaches a predetermined value that is lower than the synchronous rated speed, a water turbine rotation speed control signal from a water turbine rotation speed detector (not shown) is sent to the servo motor 15 of the first needle valve 7. This signal is transmitted via the governor to start controlling the opening degree of the needle valve 7 in response to changes in the rotational speed of the water turbine. In other nozzle pipe sections 4, 5, and 6, a closing control signal is transmitted to a deflector operating device (not shown) to control the deflectors 12, 13, and 14 to close and cut off the water flow. Opening control for the needle valves 8, 9, and 10 continues. Note that the deflector 11 is left open. Thereafter, when the water turbine is controlled to the synchronous rated speed by controlling the opening of the needle valve 7 and connected to the system, the deflector operating device (not shown) is operated to control the opening of each of the deflectors 12, 13, and 14, which are not shown. A signal is transmitted to control the opening of each nozzle pipe, and the needle valves 7, 8, 9, and 10 of each nozzle pipe are opened to shift to a predetermined load operation.

In the above embodiment, one needle valve 7 was first opened slightly, and the remaining needle valves 8, 9, and 10 were also opened slightly at the same time or immediately after, but depending on the load situation or operation required by the system. Due to the water level, only a portion of the remaining needle valves, ie, the needle valve 9 as an example, may be slightly opened.

Further, as shown in the time diagram shown in Fig. 3, when the water turbine rotation speed reaches a specified value lower than the synchronous rated speed, the first needle valve 7 is operated in accordance with the change in the water turbine rotation speed, as in the above embodiment. At the same time, the other needle valves 8, 9,
Regarding No. 10, the opening control is stopped to maintain the small opening at the time when the water turbine rotation speed reaches the specified value, and each deflector 12, 13,
Regarding No. 14, the water flow is interrupted by controlling the opening of the needle valve 7 in the same manner as in the above embodiment, and then the water turbine is controlled to the synchronous rated speed by controlling the opening of the needle valve 7. Each deflector 12, 13, 14 can be controlled to open, and each needle valve 7, 8, 9, 10 can be opened to shift to a predetermined load operation. Note that, as in the case of the embodiment shown in FIG. 2, the opening of only a portion of the needle valves 8, 9, and 10 other than the needle valve 7 may be controlled.

In each embodiment, the first needle valve 7 was selected, but the other needle valves 8, 9, 1
Of course, it may be any one of 0.

As is clear from the above description, according to the present invention, when starting a multi-nozzle Pelton turbine and transitioning to load operation, when the turbine starts and accelerates, one or more nozzles are used to Because the water flow from the nozzle accelerates the water turbine, it can be started extremely quickly.Furthermore, in the water turbine rotation control part, which is the most difficult part of startup control, one nozzle can control the rotation speed and water flow on a one-to-one basis, making it extremely easy to start. The rotation speed can be controlled.

In addition, for example, when there is a demand for full load, for some needle valves, the water flow is continued by a deflector midway, and the opening control is continued even when the water flow is interrupted (for example, needle valves 8, 9, and 10 in Fig. 2). (opening control), it is possible to shift to full load extremely quickly even after the water turbine shifts to load operation after synchronous parallel entry.

In addition, depending on the load required by the system, some needle valves can be kept slightly open when the deflector is out of service, thereby adjusting the water flow and reducing the fluid force applied to the deflector. It can also reduce the burden on the equipment. Furthermore, since the number of needle valves to be controlled can be selected based on the load condition required by the system or the operating water level, it is possible to implement a rational startup method depending on the situation.

〔Effect of the invention〕

As described above, according to the present invention, when starting a multi-nozzle Pelton water turbine, it is possible to shift to a predetermined load operation extremely quickly by utilizing the multi-nozzle structure, and to perform accurate control. This allows you to select a reasonable startup method depending on the situation.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a four-nozzle Pelton water turbine to which the present invention is applied, and FIGS. 2 and 3 are time diagrams showing an embodiment of the starting method according to the present invention. 3, 4, 5, 6... Nozzle pipe, 7, 8,
9, 10... Needle valve, 11, 12, 13, 1
4...Deflector.

Claims (1)

[Claims] 1. A bucket that rotates in response to water flow, and a plurality of nozzles arranged on the outer periphery of the bucket,
Each of these nozzles is a multi-nozzle Pelton turbine equipped with a nozzle pipe, a needle valve built into the nozzle pipe, and a deflector attached to the tip of the nozzle pipe. When transitioning from startup to a predetermined load operation, first the predetermined load operation is performed. While the nozzle deflector is open, the needle valve is slightly opened to start the water turbine, and the needle valve of the other nozzle is also slightly opened to accelerate the water turbine, after which the water turbine rotation speed reaches a specified value lower than the synchronous rated speed. Then, the opening degree of the needle valve of the predetermined nozzle is controlled according to the change in the rotational speed of the water turbine, and the water flow ejected from the other nozzles is cut off by a deflector, and then the water turbine is controlled to the synchronous rated speed. A method for starting a multi-nozzle Pelton water turbine, characterized in that, at the same time, the deflectors of the other nozzles are opened and the needle valves of the respective nozzles are opened to shift to a predetermined load operation. 2. The multi-nozzle Pelton water turbine according to claim 1, characterized in that when the water jet ejected from the other nozzle is cut off by a deflector, the opening of the needle valve of the other nozzle is controlled. starting method. 3. The multifunction device according to claim 1, wherein the needle valve of the other nozzle is held at a small opening when the water flow ejected from the other nozzle is cut off by the deflector. How to start a nozzle Pelton turbine.