JPH0676765B2 - Turbin high speed valve controller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a turbine high speed valve control device for controlling the output of a steam turbine at high speed.

[Conventional technology]

Conventionally, an apparatus of this type has been shown in FIG.
In the figure, 1 is a high pressure turbine, 2 is the high pressure turbine 1
3A is a low pressure first stage turbine, 3B is a low pressure second stage turbine, 4 is a generator for converting the rotational energy of the turbine into electrical energy, and 5 is the above-mentioned. Rotating shaft in which the turbine and the generator 4 are integrally coupled together, 6 is a control valve for adjusting the flow rate of steam supplied to the high-pressure turbine 1, and 7A is a reheater 2 supplied to the low-pressure first-stage turbine 3A. Intercept valve for adjusting the flow rate of the reheated steam from the reheater, 7B is an interception valve for adjusting the flow rate of the reheated steam from the reheater 2 supplied to the low pressure second stage turbine 3B, and 8 is a generator. Detecting an accident that occurred in the power transmission system to which the output of 4 is connected, the intercept valve 7A and
This is a turbine high-speed valve control circuit for promptly controlling the opening of 7B.

Next, the operation of the conventional device shown in FIG. 4 will be described.
When an accident occurs in a connected transmission line (not shown) that connects the power generation output of the generator 4 to another system, the turbine high speed valve control circuit 8 operates by detecting the accident and sends an opening / closing command to the intercept valves 7A and 7B. Output. As a result, the openings of the intercept valves 7A and 7B change as shown in FIG.
In the figure, t ₁ is the closing dead time including the accident detection delay,
t ₂ is the fully closed time, t ₃ is the fixed open time required to start opening the valve, and t ₄ is the fully open time. Here each time
t ₁ , t ₂ and t ₃ are set to the shortest possible time in consideration of the response characteristics of the turbine high speed valve controller. In this way, the fully closed intercept valve 7 is opened at a predetermined time t ₄ and returns to the fully open position.

FIG. 6 shows changes with time in turbine output during turbine high-speed valve control (curve T), changes in output from the generator 4 (curve G), and changes in steam pressure inside the reheater 2 (curve V). ). Ie intercept valve 7A
And low pressure turbines 3A and 3B
As the steam flow rate of the reheater 2 supplied to the turbine rapidly decreases, the turbine output, that is, the value of the output of the high pressure turbine 1 and the output of the low pressure turbines 7A and 7B rapidly decreases as shown by the curve T. As shown by the curve V, the steam pressure inside the reheater 2 rapidly rises. At the same time,
The output of the generator 4 also greatly oscillates as shown by the curve G around the turbine output shown by the curve T so as to follow the change of the turbine output.

[Problems to be solved by the invention]

Since the conventional turbine high-speed valve control device is configured as described above, the turbine high-speed valve control circuit 8 operates due to a power line accident or the like, and the intercept valves 7A and 7B are operated.
If the valve is suddenly closed, the steam pressure inside the reheater 2 will increase so much that the safety valve will operate, and it will be necessary to reinforce the pressure of the reheater 2 itself. Further, if the intercept valves 7A and 7B are opened too quickly in an attempt to suppress the rise in steam pressure inside the reheater 2, the generator 4 loses synchronism and loses synchronism during the opening control. There is a problem, and further, there is a problem that the output of the generator 4 is greatly changed and a great fluctuation is given to the power system.

The present invention has been made to solve the above problems, suppresses the rise in steam pressure in the reheater, and prevents out-of-step of the generator in the process of opening the intercept valve. An object of the present invention is to obtain a turbine high-speed valve control device that can reduce fluctuations in output to reduce fluctuations in a power system.

[Means for solving problems]

The turbine high-speed valve control device according to the present invention is configured such that a plurality of intercept valves are divided into a plurality of groups and each turbine high-speed valve control circuit for controlling opening / closing of the intercept valves is provided for each group.

[Action]

The turbine high-speed valve control device according to the present invention utilizes the energy of the reheat steam by providing a difference in the time to start closing the intercept valve, the time to start opening the intercept valve, and the opening speed for each group of intercept valves by each turbine high-speed valve control circuit. Adjusts the output of the rotating low pressure turbine.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, the same parts as those in FIG. 4 are shown with the same reference numerals, and in FIG. 1, 8A detects an accident that has occurred in the power transmission system to which the generator 4 is connected, and reheats steam to the low-pressure turbine 3A. The first turbine high-speed valve control circuit for rapidly controlling the opening degree of the intercept valve 7A that supplies electricity, 8B detects an accident that has occurred in the power transmission system to which the generator 4 is connected, and reheats the low-pressure turbine 3B. It is a second turbine high speed valve control circuit for promptly controlling the opening degree of the intercept valve 7B that supplies steam.

Next, the operation will be described. When an accident occurs in a power transmission system (not shown) to which the generator 4 is connected, the accident is detected and the first and second turbine high speed valve control circuits 8
A and 8B operate to output opening and closing commands to intercept valves 7A and 7B, respectively.

As a result, the opening degree of the intercept valve 7A changes as shown in FIG. In the figure, t _1A is the closing dead time including the accident detection delay, t _2A is the full closing time, t _3A is the opening dead time required to start opening the valve, and t _4A is the full opening time.
Here, the respective times t _1A , t _2A , t _3A are set as short as possible in consideration of the response characteristics of the turbine high speed valve control device. Once in this manner, fully closed the intercept valve 7A is opened in a predetermined time t _4A, returning to the fully open position.

At the same time, the opening of the intercept valve 7B changes as shown by the solid line in FIG. 2 (b). In the figure, t _1B is the closing dead time including the accident detection delay, t _2B is the fully closed time, t _3B
Is the immobilization time required to start opening the valve, and t _4B is the fully open time. Here, the respective times t _2B and t _3B are set as short as possible in consideration of the response characteristics of the turbine high speed valve control device. Once in this manner, the intercept valve 7B which fully closed is opened in a predetermined time t _4B, returns to the fully open position.

In the figure, the time t _{1B that} is the closing time is the same as the time t 1.
_The full-open time t _4B is set to be longer than the full-open time t _{4A at} a time delayed by a certain time from _1A . Fig. 2 (b)
The alternate long and short dash line in Fig. 2 is the intercept valve 7A in Fig. 2 (a).
The opening curve of is shown for comparison.

3 (a) and 3 (b) show changes with time in turbine output (curve T), changes in output of the generator 4 with time (curve G), and reheater during turbine high-speed valve control according to the present invention. It is the figure which showed the time-dependent change of the vapor pressure inside 2 (curve V). That is, by rapidly closing the intercept valve 7A, the flow rate of steam supplied to the low-pressure first-stage turbine 3A sharply decreases, so the turbine output, that is, the output of the high-pressure turbine 1, the output of the low-pressure first-stage turbine 3A, and the low-pressure The total value of the outputs of the second-stage turbine 3B decreases abruptly as shown by the curve T. After opening the fully closed intercept valve 7A, intercept valve 7B continues.
After a quick close, return to full open at relatively slow time t _4B .
As is clear from a comparison of both curves in FIG. 2 (b), the time taken for the intercept valves 7A and 7B to be fully closed is shifted, so that the reduction range of the turbine output in the present invention shown by the curve T is the same as in the prior art. Small enough compared to that. As shown by the curve V, the steam pressure inside the reheater 2 does not rise very rapidly because the closing time of the outlet pipe is shifted, and the rise amount is small. At this time, the output of the generator 4 also oscillates following the change in the turbine output shown by the curve T, with the amplitude being relatively smaller than that of the conventional device as shown by the curve G with the turbine output as the center. .

It should be noted that in the above embodiment, a plurality of intercept valves are used.
It is shown that it is divided into one group and controlled by the output signals from the two turbine high-speed valve control circuits. However, three or more intercept valves are divided into three or more groups and three or more turbine high-speed valve control circuits are used. The output signals of the reheaters may be controlled so that the closing times of the outlet lines of the reheater are offset from each other.

[Effects of the Invention] As described above, according to the present invention, since the plurality of intercept valves are divided into a plurality of groups and the opening / closing times of the intercept valves are shifted to control the opening / closing, the steam pressure inside the reheater is increased. To prevent the safety valve from operating by suppressing the rise in the power supply, and to prevent the pressure resistance design of the reheater from being raised more than necessary, and to prevent the output fluctuation of the generator to give excessive fluctuation to the power system. Therefore, it is possible to obtain the effect that it is possible to prevent loss of synchronization due to loss of synchronization of the generator during the recovery of the turbine output.

[Brief description of drawings]

FIG. 1 is a block diagram showing a turbine high speed valve controller according to an embodiment of the present invention, and FIGS. 2A and 2B are characteristics showing an opening / closing operation of an intercept valve in the embodiment of the present invention. FIG. 3, FIG. 3 (a) and FIG. 3 (b) are characteristic diagrams respectively showing changes with time of the turbine output, the generator output and the steam pressure of the reheater when controlled by an embodiment of the present invention, FIG. 4 is a block diagram showing a conventional turbine high-speed valve control device, FIG. 5 is a characteristic diagram showing the operation of an intercept valve in the conventional device, and FIGS. 6 (a) and 6 (b) are the conventional device. FIG. 4 is a characteristic diagram showing changes over time in the turbine output, the generator output, and the steam pressure of the reheater when controlled by. In the figure, 1 is a high pressure turbine, 2 is a reheater, 3A and 3B are low pressure turbines, 4 is a generator, 7A and 7B are intercept valves, and 8A and 8B are turbine high speed valve control circuits. In the drawings, the same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Sugimoto 2109 Nohama, Yamachi Nishimachiko, Takamatsu City, Kagawa Prefecture, Shikoku Electric Power Co., Inc. Hama 2109, Shikoku Electric Power Co., Inc., R & D Laboratory (72) Inventor, Ryumi Maeda 2109, Shikoku Electric Power Co., Ltd., Tachiyuki Sasaki, Tokyo 5-34-3 Shiba, Minato-ku, Mitsubishi Heavy Industries Ltd., Motor Business Headquarters (72) Inventor Eiji Hori 2-1-1, Niihama, Arai-cho, Takasago-shi, Hyogo Mitsubishi Heavy Industries Ltd. Takasago Works (72) Inventor I Yu Tokubo 2-4-1, Shiba Park, Minato-ku, Tokyo Within Mitsubishi Hara-Kiri Kogyo Co., Ltd. (72) Inventor Fujio Ishiguro Kobe, Hyogo Prefecture Hyogo-ku Wadasaki-cho 1-chome No. 1 No. 2 Mitsubishi Electric Corporation control in the Works (56) Reference Patent Sho 59-113216 (JP, A)

Claims (1)

[Claims] 1. A turbine high-speed valve control device for detecting the occurrence of an accident in a transmission line connected to a power output of a steam turbine generator, fully closing an intercept valve, and then controlling the valve to be fully open. A turbine high-speed valve characterized in that each valve is divided into a plurality of groups, and each turbine high-speed valve control circuit outputs each opening-closing control signal that gives a different closing start time and full-open time to each group. Control device.