| 摘要 |
<p>PURPOSE: To attain improved control by calculating enthalpy by using measured mass flow rate and the other variables, and controlling a heat exchanger by using them. CONSTITUTION: Steam passing through a steam pipe line 1 is adjusted by a valve 2, and the temperature of a heat exchanger 3 is adjusted. A mass flow rate (m') is measured by measuring a pressure differenceΔP in an orifice placed in the steam pipe line 1. On the other hand, a specific enthalpy h0 of an operating medium outflowing from the heat exchanger 3 is calculated by measuring a temperature T0 of condensate and a difference between this and an inflowing specific enthalpy hi is multiplied by the mass flow rate (m') so that a transmitted enthalpy E can be calculated. Then, this enthalpy flow is inputted to an enthalpy control unit EC as the correction value of temperature control, and the valve 2 is adjusted. Thus, the improved temperature control can be attained.</p> |
