JPH01281304A - Method and device for controlling warming-up operation of moisture content separating heater - Google Patents

Abstract

PURPOSE:To prevent the generation of the excessive thermal stress of a header part, by a method wherein, in a title device for on atomic power plant, a steam control valve for warming-up is regulated so that a temperature difference between the inner and the outer wall of the header part of a moisture content separating heater is kept at a value in a given range. CONSTITUTION:Inner and outer temperatures TX and TO of a head part are detected by means of thermocouples 18 and 19. A difference T between detecting temperature signals 20 and 21 is calculated by a subtracter 22, and a function generator 23 generates a valve opening signal (y) by means of which a valve opening is reduced to a low value when the temperature difference T is high, and a valve opening is increased to a high value when T is low. Meanwhile, when a header inner wall is a warming up target, a valve opening signal (x) is generated by a function generator 24. A low value selector 25 selects the one, being lower, of the two valve opening signals (x) and (y) to regulate the opening of a valve 27 for warming-up through an actuator 26, and an amount of steam to a heater header 8 is controlled. This constitution prevents the generation of the excessive thermal stress of a header part.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a control method for warming up a moisture separating heater of steam turbine equipment in a nuclear power plant, and also relates to a control device. .

[Conventional technology]

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

Steam 31 containing moisture leaving the high-pressure turbine passes through a moisture separator 2, is heated by a first-stage heater 3 and a second-stage heater 4, and then flows into a low-pressure turbine 32.

The heated steam of the first stage heater 3 is extracted from the oil air 5 of the high pressure turbine, and the steam is made to flow into the first stage heater header 6. The heated steam of the second stage heater is taken out from the main steam line of the nuclear reactor 7 and is made to flow into the second stage heater header 8. Regarding this type of technology, Japanese Patent Laid-Open No. 59-221503 is known.

[What the invention tries to solve! M]

FIG. 5 shows the detailed structure of the heating steam chamber header section, and the steam IO flowing in from the heating steam inlet nozzle 9 is
The steam flows into the heat exchanger tube (heat exchange U tube) inserted and welded into the heated steam, heats the steam to be heated, and then flows out from the heated steam outlet nozzle 12. When warming up this heating steam chamber, the chamber 13 on the heated steam side of the tube sheet 11. While the chambers 14 and 15 on the inside of the heating steam room are directly exposed to steam, the space 16 outside the heating steam room is not a part where steam flows. Especially when warming up, warm-up steam at about 150°C flows into the header section 17, which is initially close to room temperature (about 20°C). If inserted, a considerable temperature difference will occur and thermal stress will occur.

The present invention has been made in view of the above-mentioned circumstances, and provides a method for controlling the header portion of a moisture separation heater so that excessive thermal stress is not generated during warm-up operation, and is suitable for implementing the above-mentioned method. The purpose of the present invention is to provide a control device that is easy to use.

[Means to solve the ws problem]

In order to achieve the above object, the present invention (i) detects the inner wall temperature and outer wall temperature of the header part with a detector,
Alternatively, detect either the inner wall temperature or the outer wall temperature and estimate the other; (ii) calculate the temperature difference between the inner and outer walls based on the above detected and calculated values;

(iu) Adjust the warm-up steam control valve so that the temperature difference is within a predetermined range.

[Effect]

According to the above configuration, by suppressing the flow rate of warm-up steam, the temperature difference between the inner and outer walls is within a predetermined range, so that excessive thermal stress does not occur.

Furthermore, warm-up can be completed as soon as possible within a limit that does not cause excessive thermal stress.

〔Example〕

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

This embodiment is an improvement of the conventional device shown in FIG. 5 by applying the present invention.

Next, the differences between the embodiment shown in FIG. 1 and the conventional example shown in FIG. 5 will be explained.

Thermocouple 18 that detects the inner wall temperature of header section 17
And the same outside 4! A thermocouple 19 for detecting temperature is provided.

FIG. 2 shows a system for controlling the amount of warm-up steam based on the inner wall temperature T1 and the outer wall temperature To detected by the thermocouples 18 and 19, and a header inner wall temperature signal Tl2O,
The temperature difference ΔT=T, -'ro from the outer wall temperature signal TO21 is calculated by the subtractor 2z. Based on this ΔT, function generator 2
3, when the temperature difference ΔT is large, a small valve opening signal is generated, and when ΔT is small, a signal that gives a large valve opening y is generated. On the other hand, the inner wall of the header is the warm-up target (in this example, 1
50℃ or below), there is a function generator 24 that generates a valve opening signal The actuator 26 of the warm-up valve 27 is operated.This allows the amount of steam flowing into the heating steam chamber 8 to be controlled by monitoring the temperature difference between the inner and outer walls so that the thermal stress generated in the heating steam chamber is within the permissible limit. can be controlled simultaneously.

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, and the warm-up steam control valve 27 is controlled.

〔Effect of the invention〕

When the control method and control device of the present invention are applied.

When warming up the moisture separation heater, it is possible to control the header so that excessive stress does not occur, and
Warm-up operation can proceed quickly within limits that do not cause excessive stress.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the control device of the present invention, with FIG. 1 being a sectional view of the vicinity of the header portion, and FIG. 2 being a control block diagram. FIG. 3 is a control block diagram of an embodiment different from the above. Figure 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...
・1st stage heater, 4...2nd stage heater, 6...1st stage heater
Stage heater header, 8... Second stage heater header, 27.
...Warm-up valve, 22.23.24...Function generator,
25...Low value selection 轡. Representative Patent Attorney Tadashi Akimoto Observation-+ Z 3y /

Claims (1)

[Claims] 1. In a method for controlling the warm-up operation of a moisture separation heater, a temperature difference between an outer wall temperature and an inner wall temperature of a heating steam room header is calculated, and if the temperature difference is within a predetermined range, 1. A method for controlling warm-up operation of a moisture separation heater, the method comprising: controlling the flow rate of warm-air steam so that the temperature of the warm-up steam is increased. 2. Warming-up operation of the moisture separator according to claim 1, wherein the temperature difference is calculated by detecting each of the inner wall temperature and the outer wall temperature, and subtracting the detected values of both. Control method. 3. Calculation of the temperature difference involves detecting either the inner wall temperature or the outer wall temperature, calculating the temperature of the other based on the detected value of either of the above, and subtracting the detected value and the calculated value. The method for controlling warm-up operation of a moisture separator according to claim 1, characterized in that the method is carried out by: 4. The method for controlling warm-up operation of a moisture separator according to claim 1, wherein the predetermined range of temperature difference is a variable and is calculated based on the header inner wall temperature. . 5. A device for controlling the warm-up operation of a moisture separation heater, comprising: (a) means for detecting the temperature of the outer wall of the heating steam chamber header; (b) means for detecting the temperature of the inner wall of the header of the heating steam chamber; (c) A subtracter that subtracts the detected values of both of the detection means, and (d) a function generator that calculates the opening degree of the warm steam control valve based on the output of the subtracter. Warm-up operation control device for moisture separation heater. 6. The above function generator that calculates the valve opening based on the subtractor output is composed of (a) a function generator that calculates the valve opening based on the inner wall temperature detection signal, and (b) both of the above. It is equipped with a low value selector that selects the low value of the valve opening degree signals respectively calculated by the function generator, and the warm-up steam control valve is controlled via the low value selector. The warm-up operation control device for a moisture separation heater according to claim 5, characterized in that: 7. A device for controlling the warm-up operation of a moisture separation heater, which includes (a) means for detecting the temperature of the inner wall of the heating steam chamber header, and (b) detecting the temperature difference between the inner and outer walls based on the detected inner wall temperature value. and (c) a function generator that calculates the opening degree of the warm-up steam control valve based on the output of the outer wall temperature difference calculator. Warm-up operation control device for separation heater. 8. The function generator described above that calculates the valve opening based on the subtractor output is (a) a function generator that calculates the valve opening based on the detection signal of the inner wall temperature, and (b) both of the above. It is equipped with a low value selector that selects the low value of the valve opening degree signals respectively calculated by the function generator, and the warm-up steam control valve is controlled via the low value selector. The warm-up operation control device for a moisture separation heater according to claim 7, characterized in that: