JPH0238847B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for controlling spray water, and particularly to a control method suitable for controlling the temperature of high-pressure fluid using spray water.

[Background of the invention]

Generally, when controlling the flow rate and temperature of a large amount of high-pressure fluid, the main control valve is divided into a plurality of valves in order to meet the manufacturing limitations of the control valve, improve economy, and reliability.

Conventional embodiments are shown in FIGS. 3 and 4. Figure 3 shows the configuration of the controlled system. The main pipe 3 is divided into two main pipes 4 and 5, which join together again through main flow control valves 1 and 2, respectively, to form an outlet main pipe 6. The flow rate adjustment device 12 adjusts the main flow rate control valves 1 and 2 in order to control the flow rate of steam flowing through the pipe 6. The temperature control circuit 8 includes spray water control valves 11 and 21 so that the steam temperature in the outlet main pipe 6 is constant.
Control the necessary spray water using the main flow control valve 1,
Inject into the main pipe through step 2. FIG. 4 shows details of a conventional temperature control circuit 8. The temperature of the fluid flowing through the outlet of the main pipe is measured by the temperature detectors 7 and 37, respectively, and the deviation from the control target temperature 13 is determined by the subtractors 14 and 24 by the proportional integral calculator 15,
25, and the spray water control valves 11, 21 are controlled based on the result. According to this method,
The point is that the same number of temperature detectors 7, 37 as the number of branched main pipes 4, 5 are required. Generally, when high-pressure fluid is mixed with spray water, due to turbulence phenomena, stable and accurate values cannot be obtained unless the temperature is measured at a certain distance from the mixing point. It is necessary to increase the distance l between the valve 1 and the temperature measurement point 7. As a result, it becomes necessary to increase the length of the main pipes 16 and 26, which has the drawback of requiring a large amount of main pipes and a large amount of space for arrangement. Furthermore, while the actual control target is the temperature at the main pipe outlet section 6, it is measured at the temperature detection points 7 and 37 on the main pipes 16 and 26, which has the disadvantage of causing control deviations. .

Conventionally, spray water control methods for high-pressure steam were discussed at the 35th American Power Conference (1973).
Bypass Stations for Better by Martin and Holly
Coordination between Steam Turbine and
Steam Generator Operation”.

[Purpose of the invention]

An object of the present invention is to provide a spray water regulating method that can be configured with a minimum number of temperature detectors and a minimum amount of main piping in temperature control of high-pressure fluid, and has improved control performance.

[Summary of the invention]

The present invention provides a plurality of main pipes that merge into one pipe, a main flow control valve that is attached to each main pipe and has a spray water intake, and a spray water in the spray water intake of each main flow control valve. The spray water is sprayed according to the temperature of the fluid in the device, which consists of a spray water adjustment valve connected via piping, a flow rate adjustment device that controls each main flow adjustment valve, and a temperature adjustment circuit that controls each spray water adjustment valve. In the spray water adjustment method that adjusts water, a temperature sensor is installed in the main piping after merging, and the total amount of spray water required to adjust the temperature of the fluid after merging is adjusted according to the opening degree of each main flow control valve. It is configured to provide a distribution and injection circuit to each spray water control valve.

[Embodiments of the invention]

Hereinafter, the present invention will be explained based on examples.

FIG. 1 shows the configuration of a controlled system according to an embodiment of the present invention. As shown in Figure 1, the main pipe 3 is divided into two main pipes 4 and 5, and then the main flow control valve 1,
2, the main pipes 16 and 26, and then merge again to form the main pipe 6. In the present invention, the temperature detector 7 is attached to the temperature control target in the main piping section 6 after merging, and the temperature control circuit 8 is provided with the opening signal 17 of the main flow control valves 1 and 2, 27
A circuit is provided to which the circuit is connected. FIG. 2 shows details of the temperature control circuit 8 in this embodiment. The temperature is measured by the temperature detector 7 at the outlet of the main pipe,
A subtracter 14 applies the deviation from the control target temperature 13 to a proportional-integral calculator 15 . On the other hand, the opening signals 17 and 27 of the main flow control valves 1 and 2 are added by an adder 41, and a sum signal 51 of the opening signals of both main flow control valves is output. The divider 42 receives the opening signal 1
7 is divided by the total signal 51 to output a signal 52 indicating the ratio of the opening degree of the main flow control valve 1 to the total opening degree of all the control valves. Similarly, the divider 43 outputs a signal 53 indicating the ratio of the opening of the main flow control valve 2 to the total opening of all the control valves. By multiplying the output signal of the proportional calculator 15 by the opening ratio signals 52 and 53 in multipliers 46 and 47, the spray valve opening request necessary for temperature adjustment is distributed to the signals 54 and 55. Ru. That is, the entire amount of spray water is distributed to each spray water control valve according to the opening degree of each main flow control valve. The monitor relay 45 monitors the total opening degree signal 51 of both main flow control valves, and when the total value of the opening degrees of the main flow control valves falls below a certain level, it sends a signal to the switching devices 49 and 50. The opening degree is switched to 0, which is set by the generator 48, and the spray water control valves 11 and 21 are closed. During normal operation, the total opening signal 51 is greater than a certain value, and the monitor relay 45 switches between switches 49 and 5.
0, the spray valve opening request signal 54,
55 is output to the spray control valves 11 and 21, and the temperature control is switched to be executed.

According to this embodiment, there is an advantage that only one temperature detector 7 is required for a plurality of main flow control valves. Further, the temperature detector 7 is connected to a plurality of main pipes 1
Since the main pipes 16 and 26 are installed after the junction, the length of the main pipes 16 and 26 can be made shorter than the distance required for establishing temperature measurement, and the amount of main pipes can be saved. In addition, the temperature detector 7 can be installed at any position on the piping as long as the distance l necessary for establishing temperature measurement is secured, and it is possible to install the temperature sensor 7 at a position closer to the control target. This has the advantage that it is possible to significantly improve the

A second embodiment of the invention is shown in FIG. In this embodiment, the spray valve opening request signal 55 necessary for controlling the spray water regulating valve 21 is subtracted from the spray valve opening request signal 54 on the spray water regulating valve 11 side by the output of the proportional calculator 15 using a subtractor 62. The calculation is performed by subtracting using , making it possible to construct a circuit more simply. Also, noting that the opening degree signals 17 and 27 of the main flow control valves are taken into the temperature control circuit 8, the total opening degree signal 51 of the main flow control valves is led to the change rate calculator 56, and the change rate The monitor relay 57 detects that the current level has exceeded a certain level, and at this time, the opening request signals 63 and 64 for the spray water control valves 11 and 21 are switched to , 61, a circuit is added which forcibly increases the opening degree to a predetermined opening value set by the signal generator 60.
With this circuit, when the main flow rate control valves 1 and 2 open rapidly, it becomes possible to increase the injection of spray water in advance, thereby making it possible to further significantly improve controllability. This circuit is particularly effective in controlling the temperature of a turbine bypass valve of a thermal power generation turbine to prevent a temperature rise when the turbine bypass valve opens rapidly due to load cutoff and steam flows out. As seen in this embodiment as described above, the present invention also has the advantage that it is easy to add circuits necessary to dramatically improve controllability.

〔Effect of the invention〕

In the present invention, the minimum number of temperature detectors,
It can be configured with a minimum amount of main piping, and the flow rate and temperature of the fluid can be controlled, improving economic efficiency.
This has the effect of improving control performance.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a controlled system to which the present invention is applied, Figs. 2 and 5 are detailed diagrams of a temperature control circuit to which the present invention is applied, and Fig. 3 is a block diagram of a controlled system according to a conventional method. , FIG. 4 is a detailed diagram of a temperature control circuit according to a conventional method. 1, 2... Main flow control valve, 3, 4, 5, 16,
26, 6... Main pipe, 11, 21... Spray water control valve, 7, 37... Temperature detector, 8... Temperature control circuit, 14, 24, 62... Subtractor, 15, 2
5... Proportional calculator, 46, 47... Multiplier, 4
2, 43...Divider, 41...Adder, 45,
57...Monitor relay, 49, 50, 59, 6
1...Switcher, 48, 60...Signal generator, 56
... Rate of change calculator, 58... Timer.

Claims (1)

[Claims] 1 Multiple main pipes that merge into one main pipe, a main flow regulating valve that is attached to each main pipe and has a spray water intake, and a spray water pipe connected to the spray water intake of each main flow regulating valve. The spray water is adjusted according to the temperature of the fluid in the device, which consists of a spray water adjustment valve connected to the main flow adjustment valve, a flow rate adjustment device that controls each main flow adjustment valve, and a temperature adjustment circuit that controls each spray water adjustment valve. In the spray water adjustment method, a temperature sensor is installed in the main piping after the merging, and the total amount of spray water required to adjust the temperature of the fluid after the merging is adjusted according to the opening degree of each main flow control valve. A spray water regulating method characterized by having a spray water regulating valve equipped with a circuit for distributing and injecting water.