JPS58106311A - Controller for temperature of heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to refreshing a temperature control device for a heater.

Conventionally, as a heater incorporating a temperature control system, one having a structure shown in FIG. 1 is known. In other words, 1 in the figure
1 is a moisture separation heater, and this heater 1 is connected with a rounded introduction pipe 2 for introducing exhaust gas from a high-pressure turbine and a supply pipe 3 for supplying heat exchange gas to a low-pressure turbine. A pipe 4 is inserted into the spinning heater 1 from the outside, and a heating section 5 is provided in a portion of the pipe 4 located inside the heater 1. Further, one end of the pipe 4 is connected to a steam supply section 6, and the other end is located on a drain tank 1 for discharging steam after heat exchange. Further, a heated steam flow rate control valve 8 is interposed in a portion of the piping 7 located between the heater 1 and the steam supply section 6. This control valve 8 has a temperature control system! is connected. This system includes a function generator io that outputs a control signal to the control valve 8, a first output section 11 that outputs a cold start signal to the function generator 10tlC, and a warm-up start signal that outputs a warm-up start signal to the generator 10. The operation of the heater having the above-mentioned structure will be described below.

First, 1. Second. The third output section 11.12.13 is programmed in a predetermined sequence to send nine chiller start signals, warm-up start signals and main steam load signals to the function generator 1.
It is output to o and to 8. However, main steam is supplied from the steam supply section 6 to the heating section 5 in the moisture separation heater 1 through the pipe 4 whose opening degree is adjusted by the control valve 8.
High pressure turbine exhaust gas introduced into the heater 1 via the introduction pipe 2 is heated. The heated steam is supplied to the low pressure turbine via the supply pipe 3. After heat exchange, the high-temperature steam flowing through the heating section 5 becomes a drain and is discharged from the other end of the pipe 4 to a drain tank 7. Note that the steam temperature (low-pressure turbine inlet steam temperature) when heat exchange steam is supplied from the heater 1 to the low-pressure turbine is determined from the viewpoint of reducing thermal stress and distortion of the low-pressure turbine, and preventing overheating of the final component of the low-pressure turbine. It is necessary to control the temperature to an appropriate level.

However, the temperature control system shown in FIG. 1 does not have any feeding or feeding of the low-pressure turbine inlet steam temperature, and the temperature control is open-loop control. The low-pressure turbine inlet steam temperature is determined based on the first and second output sections 11 and 12 that output a cold start signal and a warm start signal, and the third output section 13 that outputs a steam load signal. 1. The amount is controlled by opening and closing the heated steam flow rate control valve 8 programmatically in a predetermined sequence.

Therefore, the low-pressure turbine inlet steam temperature cannot be precisely controlled, and sometimes exceeds control values such as the rate of temperature change. The present invention was made in view of the above circumstances, and it is possible to control the low-pressure turbine inlet steam temperature from low load. The present invention aims to provide a temperature control device for a heater that can be finely controlled up to high loads.

Hereinafter, the present invention will be explained in detail based on the embodiment shown in FIG. Components similar to those shown in FIG. 1 will be given the same village names and their explanations will be omitted.

The part surrounded by the dashed-dotted line in Figure 2 is the wet separation heater 1.
14 is an output section that outputs a signal of the main steam load. This output section 14 is connected to a first subtractor 1 as a comparator via a first function generator 15 which converts the pressure from the output section 14 into a temperature variable.
It is connected to 6. Further, reference numeral 11 in the figure is a detector provided at the outlet side piping 4 portion of the heated steam flow rate control valve 8 to detect the outlet pressure of the scissors control valve 8. This detector 11 is connected to a 20th function generator 18 which converts the pressure into a temperature variable, and the mosquito generator 11 is connected to a second subtraction function generator 18, which receives the signal of the turn signal f4 differential 1# of the heater 1. 10. Further, this second subtracter 20 is connected to the first subtracter 16. The first subtractor 16 is disconnected from the PI controller 2xK that controls the opening degree of the control valve 8.

Next, control of the low pressure turbine inlet steam temperature (the outlet steam temperature of the supply pipe 3 of the heater 1) by the temperature control device having the above configuration will be explained. First, the outlet steam pressure of the heating gA degree wave flow rate control valve is detected by the detector 17, and this pressure detection value is used as the second
The saturated steam temperature at the outlet of the control valve 8 is determined from K by temperature conversion by the function generator 18. However, this saturated steam temperature is outputted to the second subtractor jOK, and the subtracter 2011
At C, the low pressure turbine inlet steam temperature is determined by subtracting the saturated steam temperature by the terminal difference of the heater 1. Tsumashi, low pressure turbine inlet steam temperature "IJ"
is expressed as TLP=TMII-ノ''.Here, T□8 is the steam temperature in the heating section 5 (T), and ΔT is the terminal difference.The low-pressure turbine inlet steam temperature LP is expressed as It is output to the first subtractor 16.

On the other hand, the main steam load is transferred from the output section 14 to the first function generator J.
5, the target temperature "LP-.t" of the low pressure turbine inlet steam is determined from the generator 1j, and this is input to the first subtractor 16.
6, the difference (T
L-・t-T, , ) is determined and outputted to the PI controller 21, and the opening command value is outputted from the controller 21 to the control valve 8 to open and close the wrinkle extension 8. Separation heater 1
Controls the temperature of steam supplied from the turbine (low-pressure turbine inlet steam temperature).

Therefore, according to the temperature control device, the outlet pressure of the heated steam flow rate control valve 8 is detected, and this is compared with the target temperature in the first subtractor 16 as a feed signal, and the PK controller 21 1, it is possible to precisely control the steam temperature at the inlet of the low-pressure turbine, and compared to a method that detects the steam temperature at the inlet of the low-pressure turbine of the moisture separation heater 1 and compares it with the target temperature by feeding it. As a result, the low-pressure turbine inlet steam temperature can be controlled with good responsiveness.

Note that the object to be controlled by the temperature control device according to the present invention is not limited to the moisture separation heater as in the above embodiment, but can be similarly applied to any heater having a heat exchanger of a system in which heating steam is saturated steam. sleep in

As detailed above, according to the present invention, by controlling the low-pressure turbine inlet steam temperature appropriately and with good responsiveness, (1) thermal stress and strain in the low-pressure turbine can be reduced (2)
) It has the effect of preventing overheating of the final blade of a low-pressure turbine, and can provide a temperature control device for a heater suitable for nuclear power plants and the like.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the temperature control system built into the heater.
FIG. 2 is an explanatory diagram of a temperature control device incorporated in a heater showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Moisture separation heater, 2...Introduction pipe, 3...Supply pipe, 5...Heating part, 6...Main steam supply part, 8...
・Heating steam control valve, 14...output part of main steam load, 1
5... first function generator, 16... first subtractor,
17...Detector, 18...Second function generator, 1#
...Terminal difference of heater, 21...
PI controller.

Claims (1)

[Claims] A device for controlling a low-pressure turbine inlet steam temperature provided in the heater by opening and closing a heated steam flow rate control valve and adjusting an amount of heated steam flowing into a heating section in the heater, wherein the control valve outlet pressure is A detector to detect, a converter to convert the pressure from this detector to temperature, a comparator to compare the temperature of this converter minus the terminal difference of the heater with the target temperature, and this comparator. 4IgIk A temperature control device for a heater, comprising: a controller that controls the opening degree of the controller based on a temperature deviation from 4IgIk.