JP2721508B2 - Warm-up separation heater control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control device for performing a warm-up operation of a moisture separation heater of a steam turbine facility in a nuclear power plant.

[Conventional technology]

FIG. 4 is a system diagram around the moisture separation heater 1 of the steam turbine equipment in the nuclear power plant.

After leaving the high-pressure turbine, the steam 31 containing moisture passes through the moisture separator 2, is heated by the first-stage heater 3 and the second-stage heater 4, and then flows into the low-pressure turbine 32. The heating steam of the first-stage heater 3 is extracted from the bleed air 5 of the high-pressure turbine, and the steam flows into the first-stage heater header 6. The heating steam of the second-stage heater is taken out from the main steam line of the nuclear reactor 7 and flows into the second-stage heater header 8. JP-A-59-221503 discloses this type of technique.

[Problems to be solved by the invention]

FIG. 5 shows the detailed structure of the header section of the heating steam chamber.
Into the heat transfer tube (U tube for heat exchange), which has been inserted and welded, and heats the steam to be heated.
Spill out of. In warming up the heated steam chamber, the chamber 13 on the heated steam side of the tube sheet 11 and the chambers 14 and 15 on the heated steam chamber side are directly exposed to steam.
16 is not a part where steam flows, so this header part 17
The temperature difference between the inner wall side and the outer wall side is likely to occur, especially when warming up. When a large amount of steam is introduced at a time, a considerable temperature difference occurs and thermal stress is generated.

The present invention has been made in view of the above circumstances, and when warming up,
It is an object of the present invention to provide a control device capable of controlling a header portion of a moisture separation heater so as not to generate excessive thermal stress.

[Means for solving the problem]

In order to achieve the above object, the present invention provides (i) detecting an inner wall temperature and an outer wall temperature of the header portion with a detector, or detecting one of the inner wall temperature and the outer wall temperature and estimating the other. (Ii) calculating the temperature difference between the inner and outer walls based on the detected and calculated values, and (iii) adjusting the warm-up steam control valve so that the temperature difference falls within a predetermined range.

[Action]

According to the above configuration, the temperature difference between the inner and outer walls is within a predetermined range due to the suppression of the flow rate of the steam for warming up, so that an excessive thermal stress does not occur.

Further, the warm-up can be completed at the earliest time within a limit that does not cause excessive thermal stress.

〔Example〕

FIG. 1 is a sectional view of an embodiment of the control device according to the present invention.

This embodiment is an improvement obtained by applying the present invention to the conventional apparatus shown in FIG.

Next, the differences between the embodiment of FIG. 1 and the conventional example of FIG. 5 will be described.

Thermocouple 18 for detecting inner wall temperature of header section 17
And a thermocouple 19 for detecting the outer wall temperature.

Figure 2 shows a system for controlling a warming-up steam quantity based on said thermocouple 18 and 19 the inner wall temperature T ₁ of the outer wall temperature T ₀ detected in. A header inner wall temperature signals T ₁ 20, calculates the temperature difference ΔT = T _I -T ₀ the outer wall temperature signal T ₀ 21 by the subtractor 22.
Based on this ΔT, the function generator 23 generates a signal that gives a small valve opening degree when the temperature difference ΔT is large, and generates a signal that gives a large valve opening degree y when the temperature difference ΔT is small. On the other hand, if the header inner wall is a warm-up target (150 ° C. or less in this example), there is a function generator 24 that generates a valve opening signal x, and the opening signal smaller than the two signals x and y is provided. Select low value selector
The actuator 26 of the valve 27 for warm-up is operated via 25. Thus, the amount of steam flowing into the heating steam chamber 8 can be controlled while monitoring the temperature difference between the inner and outer walls so that the thermal stress generated in the heating steam chamber is within an allowable limit.

FIG. 3 shows an embodiment different from the above. In this example, the outer wall temperature is calculated from the header inner wall temperature signal 20 and the temperature difference ΔT
Is calculated to control the steam control valve 27 for warming up.

〔The invention's effect〕

By applying the control device of the present invention, when performing the warm-up operation of the moisture separation heater, it is possible to control so that excessive stress is not generated in the header portion, and within a limit that does not cause excessive stress. Warm-up operation can be advanced immediately.

[Brief description of the drawings]

1 and 2 show an embodiment of a control device according to the present invention. FIG. 1 is a sectional view showing the vicinity of a header portion, and FIG. 2 is a control block diagram. FIG. 3 is a control block diagram of an embodiment different from the above. FIG. 4 is a system diagram around the moisture separator. FIG. 5 is a sectional view of a conventional example. 1 ... Moisture separation heater, 2 ... Moisture separator, 3 ... First
Stage heater, 4 ... Second stage heater, 6 ... First stage heater header, 8 ... Second stage heater header, 18 ... Thermocouple for inner wall temperature detection, 19 ... For outer wall temperature detection Thermocouple, 20 …… Inner wall temperature signal, 21 …… Outer wall temperature signal, 22 ……
Subtractor, 23, 24 ... Function generator, 25 ... Low value selector, 27
…… Valve for warm-up, 30 …… Header temperature distribution calculator.

Claims (2)

(57) [Claims] An apparatus for controlling a warm-up operation of a moisture separation heater, comprising: means for detecting an outer wall temperature of a heating steam chamber header;
Detecting means for detecting the inner wall temperature of the heating steam chamber header, subtracting means for subtracting the detection values of the two detecting means, and warming which can adjust the amount of steam supplied to the heating steam chamber header based on the output of the subtracting means. A function generator for calculating the opening of the steam control valve, a function generator for calculating the opening of the warm-up steam control valve based on the detection signal of the inner wall temperature, and a function generator for calculating the opening of the steam control valve, respectively. A low value selector for selecting a low value from the valve opening signal, and controlling the warm-up steam control valve via the low value selector. Machine operation control device. 2. An apparatus for controlling a warm-up operation of a moisture separation heater, comprising: means for detecting an inner wall temperature of a heating steam chamber header;
Means for calculating the temperature difference between the inner and outer walls based on the detection value of the inner wall temperature detecting means, and warm-up which can adjust the amount of steam supplied to the heating steam chamber header based on the output calculated by the means. A function generator for calculating the opening of the steam control valve;
A function generator for calculating the opening of the warm-up steam control valve based on the detection signal of the inner wall temperature, and a low value selection for selecting a low value of the valve opening signals respectively calculated by the two function generators And a heater for controlling a warm-up steam control valve via the low value selector.