Analysis to speed up of the start-up of steam boiler OP-380

During operation of the OP-380 boiler under transient conditions, for example during start-up and shutdown of the power unit, on the circumference of horizontal pressure elements like a drum, inlet and outlet headers, considerable temperature differences are observed. The duration of each start-up and shutdown is relatively long because is limited by thermal stresses caused by temperature changes. The paper presents the method of the maximum stresses arising during operation in transient states determination, based on the measurement of temperature on the outer surface of the thick-walled pressured element. The presented measuring system, including the described method has been implemented in the OP-380 boiler at EDF Krakow. This system will act as a thermal constraints system, whose main task is to protect the equipment against exceeding the maximum allowable thermal stress. This method will also allow assessment of the viability of thick-walled components based on the values of the stresses that occur during long-term operation of the boiler.