JPS5687720A - O2-density controlling system utilizing steam damp control - Google Patents

Abstract

PURPOSE:To enable to automatically determine the boiler load that has been determined conventionally by the operator himself, by employing an arrangement capable of determining the boiler load (control of the opening of a damping valve) through comparison of an actual concn. of oxygen and a reference value. CONSTITUTION:In a tanker using diesel engines as a prime mover, for instance, there is provided an auxiliary boiler for forming inert gas, and the boiler is controlled such that its load corresponds to the required concn. of oxygen. In controlling the boiler operation, a fuel control valve 16 is controlled on the basis of the deviation between an actual steam pressure and a reference value, while a combustion-air controlling unit 18 is supplied with a value obtained by dividing 38 the output of an air-flow rate oscillator 36 by the output of an air-fuel curve generator 56 via a comparator 58, etc. for controlling the flow rate of combustion air. Further, the output of an O2-concn. oscillator 44 is compared at 60 with a reference value 68 to control a steam damp controlling means 12 in response to the result of the above comparison by a damp control selecting switch 53 which is shifted to the IGS.ON side at the time of supplementing inert gas.