| 摘要 |
PURPOSE:To make it possible to discharge cold water by stabilizing the control system and by minimizing the temperature difference between the water at the cold water intake port and that at the cold water outlet port of a thermoelectric power plant or an atomic power plant by a method wherein a flow rate correction signal is prevented from being outputted unnecessarily while a proper flow rate correction signal is outputted in accordance with the condition of the power plant. CONSTITUTION:In case where the temperature difference DELTATA between the water at the cold water intake port and that at the cold water outlet port increases higher than the detecting value of a temperature difference detector 19 and the resetting of an integrator 4 is released, if the opening degree eta2 of a cooling water pump is below its lower limit value, an opening degree detector 18 for detecting the lower limit position of the pump is operated and a decreasing side locking circuit 15 functions to interrupt the decreasing side integration by the integrator 4 so that even when an error signal epsilonT regarding the above mentioned temperature difference DELTATA is on the decreasing side, no integration is made and no unnecessary flow rate correction signal Q2 is outputted. Further, when the temperature difference DELTATA exceeds a set value DELTATS of the temperature difference, the error signal epsilonT becomes positive in polarity and inputted to the integrator 4 after it is multiplied by a coefficient through a function generator 13 so that the flow rate correction signal Q2 is outputted and the temperature difference DELTATA is controlled to become lower than the set value DELTATS. Thus, when the temperature lowers below the set value and in this case, if the error signal epsilonT is within the negative polarity side blind zone, the output F1 of the function generator 13 becomes zero and accordingly, the flow rate correction signal Q2 becomes constant as it is kept in status quo. |
