JPS60113001A - High-speed valve-control device of turbine - Google Patents

Abstract

PURPOSE:To prevent a generator from its step out when a turbine is on the way of recovering its output, by both open-close operating an intercept valve and closing a control valve, when a transmission line causes a fault, so as to control the control valve to be opened after the transmission line is confirmed to be successfully reclosed by a breaker. CONSTITUTION:A turbine high-speed valve-control circuit 81, detecting a fault caused in a transmission line 9a or 9b connecting a generator 4 through a bus 10 in an end side of the transmission line, operates generating an open-close instruction to an intercept valve 7 simultaneously outputting a closing instruction to a control valve 6 to its certain partial position. Successively, the turbine high-speed valve-control circuit 81 is operated outputting an opening instruction to the control valve 6 after confirming breakers 12a, 13a or 12b, 13b, connected to both ends of the transmission line causing the fault, to surely succeed in their reclosing. Accordingly, the withstanding pressure of a reheater 2 or the like is not required to be designed higher than necessary by suppressing a pressure rise of steam inside the reheater 2 so as to prevent a safety valve from operating.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a turbine high-speed pulp control device that controls the output of a steam turbine at high speed.

[Prior art]

A conventional device of this type is shown in FIG.

In the figure, 1 is a high-pressure turbine, 2 is the high-pressure turbine 1
6 is a low-pressure turbine, 4 is a generator for converting the rotational energy of the turbine into electrical energy, and 5 is a rotating shaft in which the turbine and generator are integrally coupled together. , 6 is a control valve for adjusting the flow rate of steam supplied to the high-pressure turbine 1, 7 is an intercept valve for fully adjusting the flow rate of reheated steam from the reheater 2 supplied to the low-pressure turbine 6, and 8 is a control valve for adjusting the total flow rate of the reheated steam supplied to the low-pressure turbine 6. This is a turbine high-speed pulp control circuit for detecting an accident occurring in the power transmission system to which the output of the generator 4 is connected and promptly controlling the opening degree of the intercept valve.

Furthermore, 9a + 9b is a two-circuit transmission line for transmitting the generated power, and 10 is the two-circuit transmission line 9a.
, 9b is the power transmission end side busbar, 11 is the power receiving end side busbar of the power transmission line, 12a and 12b are the power transmission side circuit breakers installed at the power transmission end side to eliminate accidents that occur in the power transmission system, and 13a are the power transmission side busbars.
, 13b is a power receiving 9111L or disconnector installed at the power receiving end to eliminate all accidents that occur in the power transmission system.

Next, the operation of the conventional device shown in FIG. 1 will be explained.

When an accident occurs in the connected power transmission line 9a or 9b that connects the generated output of the generator 40 to another system, the accident is detected and the turbine high-speed valve control circuit 8 operates to output an opening/closing command to the intercept valve 7. . As a result, the opening degree of the intercept valve 7 changes as shown in FIG. 1+ in the diagram
is the closing immobility time including accident detection delay, etc., t is the fully closing time, t.

is the opening immobility time required until the valve starts to open, and t4 is the full opening time. Here, the respective times tl+jt, t
, ti is set to the shortest possible time in consideration of the response characteristics of the methane high-speed pulp control device.

The intercept valve 7, which is once fully closed in this manner, is opened at a predetermined time t4 and returns to the fully open position.

In addition, an accident that occurs on the power transmission lines 9a, 9b can be caused by the breakers 12a, 13 connected to both ends of the power transmission lines 9a, 9b.
After being removed by opening a, 12b, 13b, the circuit is reclosed after a while. Until the breaker is reclosed, the power generated by the generator 4 is transmitted through either one of the two-circuit power transmission lines 9a and 9b. Also, if the accident continues when the breaker is reclosed, the breaker 12a, 13a or 12b, 1, ! connected to both ends of the transmission line will be closed. Sb is opened again, and the power generated at this time is transferred to the power transmission line 9.
Power is transmitted through either one of the transmission lines a or 9b.

FIG. 3 is a diagram showing temporal changes in turbine output and temporal changes in steam pressure inside the reheater during turbine high-speed valve control. In other words, by quickly closing the intercept valve 7, the flow rate of steam supplied to the low pressure turbine 6 from the reheater 2 rapidly decreases, so that the sum of the turbine output and the low pressure turbine output suddenly decreases. At the same time as the pressure decreases, the steam pressure inside the reheater 2 increases rapidly.

Since the conventional turbine high-speed valve device is configured as described above, when the turbine high-speed valve control circuit 8 is activated due to a power transmission line accident and the intercept valve 7 is suddenly closed, the steam pressure inside the reheater 2 is reduced. The rise becomes so large that a safety valve may operate, or the reheater 2 itself must be reinforced with pressure resistance. Furthermore, if the full opening time of the intercept valve 7 is made too early in an attempt to suppress the rise in steam pressure inside the reheater 2, the synchronization of the generator 4 cannot be maintained in the middle of the U opening control, resulting in loss of synchronization. There were drawbacks.

In addition, without confirming that the transmission line has been successfully reclosed, the intercept valve is opened within a predetermined program time to restore the turbine output to the rated output.
When the power transmission line reclosing operation fails, power must be transmitted through either one of the lines 9a or 9b of the two-line power transmission line, which has the drawback of overloading the power transmission line.

[Summary of the invention]

This invention was made in order to eliminate the disadvantages of the conventional ones as described above, and in addition to controlling the opening and closing of the intercept valve 7 and the adjustment valve 6 at the same time, the above-mentioned adjustment is performed after fully confirming that the power transmission line has been reopened. By returning the valve to the fully open position, it suppresses the rise in steam pressure in the reheater, prevents the generator 4 from stepping out during the intercept valve opening process, and prevents overloads such as power transmission H in the event of failure in re-closing. It is the object of the present invention to provide a turbine high speed nozzle control device that can prevent the above problems.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 4, the same parts as in FIG. 1 are indicated by the same reference numerals. In FIG. At the same time, the turbine high speed valve control circuit outputs an opening command to the control valve 6 after confirming that the power transmission line has been reclosed.

Next, the operation will be explained. When the Oz generator 4 detects an accident that has occurred in the power transmission #9a or 9b connected via the power transmission end bus 10, the turbine high speed valve control circuit 81 operates and at the same time issues an opening/closing command to the intercept valve 7. , outputs a closing command to the control valve 6 at a certain partial position 1. Next, the circuit breaker 1 connected to both ends of the accident power line
2a.

After confirming that the re-closing of ISb 16a, 12b and ISb has been reliably successful, the turbine high speed pulp control circuit 81 is operated and an opening command is output to the control valve 6. As a result, the opening degrees of the intercept valve 7 and the control valve 6 change as shown in FIGS. 5a and 5b. That is, in the figure, ts is the immobility time consisting of a delay in accident detection, j6 is the closing time to the partial position, t7 is the confirmation time until the re-closing of the power transmission line is confirmed and the control valve starts to open, t, is the open circuit time. At this time, the intercept valve 7 is opened and closed in the same manner as in the conventional device.

FIGS. 6a and 6b show temporal changes in turbine output and temporal changes in steam pressure inside the reheater during turbine high-speed pulp control according to the present invention. Since the regulating valve 6 is held at the partial load position until the breaker confirms that the transmission line has been successfully reclosed, the turbine output also drops rapidly, then maintains the partial load output, and finally gradually increases to the full load output. to recover. On the other hand, the steam pressure inside the reheater 2 tries to rise by quickly closing the intercept valve 7, but the steam pressure inside the reheater 2 immediately closes.
Since the flow rate of steam flowing into the reheater 2 is restricted by closing the reheater 2, the steam pressure inside the reheater 2 increases significantly as in the conventional device.

〔Effect of the invention〕

As described above, according to the present invention, when controlling the turbine high-speed pulp in the event of an accident on a power transmission line, the intercept valve is first opened and closed, and at the same time, the moderation valve is closed immediately after the accident, and the power transmission line is reclosed by the circuit breaker. Since we have adopted a control method that opens after confirming success, we can suppress the rise in steam pressure inside the reheater and prevent the safety valve from operating, making it possible to make the pressure-resistant design of the reheater and other devices higher than necessary. In addition, it is possible to prevent the generator from losing synchronization during recovery of the turbine output. Further, there is an excellent effect of reliably preventing overload of the power transmission line, etc., which would occur during the period until the power transmission line is reclosed by the circuit breaker and after the reclosure fails.

[Brief explanation of drawings]

Fig. 1 is a block configuration diagram showing a conventional turbine high-speed pulp control device, Fig. 2 is a characteristic diagram showing the operation of an intercept valve in the conventional device, and Fig. 3 a and b are diagrams showing the operation of the intercept valve in the conventional device. FIG. 4 is a block diagram showing a turbine high-speed pulp control device according to an embodiment of the present invention, and FIGS. Characteristic diagrams showing the operation of the intercept valve and control valve in one embodiment, Figures 6a and b are characteristic diagrams showing changes over time in turbine output and reheat steam pressure when controlled by one embodiment of the present invention. It is. 1... High pressure turbine, 2... Reheater, 6... Low pressure turbine, 4... Generator, 6... Additional valve, 7...
Intercept valve, 8.81... Turbine high speed valve control circuit, 9 b, 9'b = Power transmission line, 12a,
12b, 16a, '13b...breaker, 12a, 1
2b...Power transmission side 17 and disconnector, 13a, 13b...
・Power receiving side breaker. Agent Masuo Oiwa Figure 3 (Al ri → Time tb) E Figure 6゜Z Figure 6 Procedures, Amendment (Spontaneous) 2 Title of Invention: Turbine high-speed pulp control device; 37 Stopper 1tl'1 ．． The relationship 'r=s', t', applicant f
L Toko Bunch 5; [2-2-3 Marunouchi, Chiyoda-ku, Miyako
Name (601) Mitsubishi Electric Co., Ltd. (1 person) Representative: Kata Yuhito, Department 4: Agent fl, Address: Tokyo Fill 2-2-3 Marunouchi, 81-ku Chiyo
No. 6, Contents of amendment (1) Amend the attached patent claims. (2) The description will be amended as follows. (3) Correct the attached circular, Figure 1. (4) Correct Figure 4 as shown in the attached sheet. 7. Attached list of VIts (1) After amendment! A document stating the scope of claims: 1 copy (2) A document stating Figure 1 after the amendment 1 copy (3) A document stating Figure 4 after the amendment 1 copy or more A document stating the amended scope of claims A turbine high-speed valve it' control device that detects the occurrence of an accident in a power transmission line to which the power generation output of a sudden turbine generator is connected, fully closes an intercept valve, and then controls it to fully open, comprising: a power transmission side bus line of the generator; It is equipped with a transmission and power receiving side breaker installed for each line between the power receiving side buses, and a turbine high-speed pulp control circuit that receives operation confirmation signals from each of the above-mentioned circuit breakers. Upon detecting an accident, the intercept valve is rapidly fully closed and then fully opened, and at the same time, the regulator valve is rapidly closed to a partial load position;
The turbine high-speed pulp control device is characterized in that the control valve is opened from a partial load position to an initial position after confirming that the power transmission line has been successfully reclosed by the breaker.

Claims (1)

[Claims] In a turbine high-speed pulp control device that detects the occurrence of an accident in a power transmission line connected to the power generation output of a steam turbine generator, fully closes an intercept valve, and then controls the intercept valve to fully open, the power transmission side bus bar of the generator and the power receiving side It is equipped with circuit breakers on the transmission and reception sides installed for each line between the side busbars, and a turbine high-speed pulp control circuit that receives operation confirmation signals from each of the circuit breakers, and is equipped with a high-speed turbine pulp control circuit that receives operation confirmation signals from each circuit breaker. detect,
At the same time as the intercept valve is quickly fully closed and then fully opened, the regulator valve is rapidly closed to the partial load position, and after confirming that the power transmission line has been reclosed by the breaker, the regulator valve is partially closed. A turbine high-speed valve control device characterized in that the valve is opened from a load position to an initial position.