| 摘要 |
PURPOSE: A temperature control circuit controls the temperature of steam and reheater steam as well as makes the flow of wasted gas of boiler smooth. CONSTITUTION: A temperature control circuit comprises an operating button(53), a temperature setter(54), a temperature controller(57), an adder(60), an analogue memory(62) and a function generator(59). The operating button(53) is operated by a worker to control flow amount of wasted gas of a boiler and generates a certain increasing/decreasing signal everytime it is pushed. The temperature setter(54) is to set up control temperature of a reheater. The temperature controller(57) controls the signal converted in a rate-of-change limiter(55) from the impressed set value of the temperature setter(54) and the signal supplied from a deviation signal(56) when the temperature setter(54) sets temperature and automatically switches control. The adder(60) adds up the output value of the temperature setter(54) via an upper/lower limit setter(58) and the function generator value which is a leading signal of total amount of air of the boiler. The analogue memory(62) converts the value added in the adder(60) by an exchanger(61), stores the converted value and operates a reheater damper for control of the amount of wasted gas of the reheater. The function generator(59) converts the output value to minus by the output of the analogue memory(62) to smooth the flow of the wasted gas in a boiler even when the flow amount of the wasted gas in the boiler is as much as to make the reheater damper closed and controls a superheater damper conversely with the reheater damper.
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