Power industry is the first national sustainable development industry. With the rapid development of
power industry, more and more large-scale units have been put into operation. 300MW, 600MW units has
become the main units, and gradually to 1000MW ultra-supercritical generating units. It is predicted that
by 2015, China's power installed capacity will exceed 1.1 billion KW. Thermal power units in the power
system will continue to dominate more than 70% of the installed capacity and reach about 800 million
KW[1]. Although China's power industry has made considerable progress, but the current national
electricity demand growth is still very fast. Power supply shortages appear from time to time. At present,
the efficiency, reliability and environmental performance of China’s new units is equivalent with the
developed countries’. However, because of large areas’ serious power shortage problems, it makes many
long-term power plant equipments work on overload. The security of the equipments also decreases. It
requires monitoring production process parameters of the power plant equipments to ensure the boilers,
turbines, generators and other host and auxiliary equipments normal operation. In addition, the increasing
capacity of the units leads to increasingly complex structures and systems. How to ensure these units safe,
reliable and cost-effective operation is very important to the development of the national economy