JPS643401A - Waste heat recovery device - Google Patents

Abstract

PURPOSE: To control a steam generating amount constant when a generated exhaust gas amount is a ventilation capacity or more of an exhaust heat boiler by providing a pressure detector at a concentrated tube and a generated steam amount detector at the boiler, operating a valve travel of a flow regulating valve of one flue in response to a deviation of a pressure detected value from a set pressure value, and operating a valve travel of a flow regulating valve of the other flue based on a deviation of a steam amount detected value from a set steam amount value, thereby controlling a pressure in the concentrated tube constantly. CONSTITUTION: A pressure detector 11 is provided at a concentrated tube 3, and a valve travel of a flow regulating valve 8 is operated by a regulater 12 based on a deviation of a pressure detected value from the detector 11 from a preset pressure set value. A generated steam amount detector 14 is provided at a waste heat boiler 7, a valve travel operating amount of a flow regulating valve 10 is calculated by a calculator 16 according to a deviation of a steam amount detected value from the detector 14 from a preset steam amount set value, and the travel of the valve 10 is operated by a regulater 17. Thus, a pressure in the tube 3 is controlled constant to control the steam generation amount constant when the generated exhaust gas amount is the ventilating capacity or more of the boiler 7 without disordering furnace pressure controls of heating furnaces 1, 2.