| 摘要 |
PURPOSE:To ensure a certain controlled variable independently of a change of a controlled system by correcting values, which turn on and off a manipulated variable, so that the time average value of the controlled variable coincides with a set value. CONSTITUTION:The temperature of cold water is inputted to an average value calculating part 7 from a detector 5 to attain a time average value of the temperature of cold water. A set value calculating part 9 performs operations to correct the upper limit value and the lower limit value, which turn on and off a heating source respectively, so that the attained time average value coincides with a set value C stored in a set value storage part 10. A correction value -k1 (<0) for turn-on/off control is attained in case of a% load, and a correction value k2 (>0) for turn-on/off control is attained in case of b% load. In case of a% load, an upper limit value U and a lower limit value L for turn-on/off control are reduced by k1 and are set to values U' and L', and thus, a time average value A of cold water coincides with the set value C. In case of b% load, the upper limit value U and the lower limit value L for turn-on/off control are raised by k2 and are set to value U'' and L'', and thus, the time average value Q of cold water coincides with the set value C. |
