High-temperature heating surface such as superheater and reheater of large-sized utility boiler all experiences a relatively severe working conditions. The failure of boiler tubes will directly impact the safe and eco...High-temperature heating surface such as superheater and reheater of large-sized utility boiler all experiences a relatively severe working conditions. The failure of boiler tubes will directly impact the safe and economic operation of boiler. An on-line life monitoring model of high-temperature heating surface was set up according to the well-known L-M formula of the creep damages. The tube wall metal temperature and working stress was measured by on-line monitoring, and with this model, the real-time calculation of the life expenditure of the heating surface tube bundles were realized. Based on the technique the on-line life monitoring and management system of high-temperature heating surface was developed for a 300 MW utility boiler. An effective device was thus suggested for the implementation of the safe operation and the condition-based maintenance of utility boilers.展开更多
An experimental investigation is performed on side wall deformation at the pendant convective pass (PCP) in a 300 MW and a 600 MW utility boiler. The temperature distributions are measured on the side wall areas of th...An experimental investigation is performed on side wall deformation at the pendant convective pass (PCP) in a 300 MW and a 600 MW utility boiler. The temperature distributions are measured on the side wall areas of the water-cooled wall, the PCP and the horizontal convective pass (HCP) in the two utility boilers. These experiments show that there are great temperature differences in the side wall areas during the startup process in both utility boilers. These temperature differences can reach 80～150 °C with the side wall temperature in the PCP area higher than those in the water-cooled wall and the HCP. The highest temperature in the PCP is close to the flue gas side temperature at the same position in the horizontal flue gas pass. Thermal stress analyses are conducted in the side wall areas in the water-cooled wall, the PCP and the HCP with the software ANSYS. The results show that, at great temperature differences, the PCP side wall undergoes negative thermal stresses that exceed the yield strength causing deformation in the PCP side wall.展开更多
文摘High-temperature heating surface such as superheater and reheater of large-sized utility boiler all experiences a relatively severe working conditions. The failure of boiler tubes will directly impact the safe and economic operation of boiler. An on-line life monitoring model of high-temperature heating surface was set up according to the well-known L-M formula of the creep damages. The tube wall metal temperature and working stress was measured by on-line monitoring, and with this model, the real-time calculation of the life expenditure of the heating surface tube bundles were realized. Based on the technique the on-line life monitoring and management system of high-temperature heating surface was developed for a 300 MW utility boiler. An effective device was thus suggested for the implementation of the safe operation and the condition-based maintenance of utility boilers.
基金supported by Program for Changjiang Scholars and Innovative Research Team in University (No. PCSIRT0720)the Overseas Returnee Scholar Foundation of North China Electric Power University, China
文摘An experimental investigation is performed on side wall deformation at the pendant convective pass (PCP) in a 300 MW and a 600 MW utility boiler. The temperature distributions are measured on the side wall areas of the water-cooled wall, the PCP and the horizontal convective pass (HCP) in the two utility boilers. These experiments show that there are great temperature differences in the side wall areas during the startup process in both utility boilers. These temperature differences can reach 80～150 °C with the side wall temperature in the PCP area higher than those in the water-cooled wall and the HCP. The highest temperature in the PCP is close to the flue gas side temperature at the same position in the horizontal flue gas pass. Thermal stress analyses are conducted in the side wall areas in the water-cooled wall, the PCP and the HCP with the software ANSYS. The results show that, at great temperature differences, the PCP side wall undergoes negative thermal stresses that exceed the yield strength causing deformation in the PCP side wall.
