Research of Ventilation in Powerhouse Coupling Plant with Thermal-compression of Long Vertical Busbars
Most of the generators in large underground power plants are led out using long vertically separated phase enclosed busbars(IPB).However,under long vertical conditions,the chimney effect caused by height differences can lead to excessive temperature differences between the upper and lower parts of the busbars,even exceeding the temperature rise limit under the maximum operating condition of the busbars,posing certain safety hazards and limiting the use of enclosed busbar lead out types in underground power plants.This article combines the characteristics of the equal length vertical and high current enclosed busbar shaft of the Three Gorges Underground Power Station,conducts theoretical analysis and numerical calculation on the thermal balance characteristics of the long vertical enclosed busbar under different influencing factors.Through engineering practice,a coupling model and regularity between the thermal balance of long vertical busbars and the ventilation of underground factory busbar shafts are explored.Based on this,a new idea for the application based on"thermal pressure coupling"and ventilation design is proposed.