The Test of Inner-flue Tube Wall Temperature of Superheater Based on the Power Plant SIS
Superheater and reheater tube failures were mostly due to excessive temperature, the inner-flue tube wall temperature of superheater make certain of tube thermal stress, material creep status and residual lifespan of tubes. So investigation of superheater safety began with experimentation of inner-flue tube wall temperature of superheater. In order to precisely learn inner-flue tube wall temperature of superheater of 600MW supercritical boiler, new measuring points are set on the superheater tube wall inner the flue. Since the working condition of 600MW supercritical boiler is quite severe, the temperature measuring points can only be used for short-term test. The data acquisition can be carried out automatically and a data storage system is required. The testing method in this paper transmit the measuring signal to the database of the thermal power control system through the redundant channel of the system. This method only requires new measuring points (thermocouple). The test data can be loaded directly from the SIS database, which saves not only money but also the work.
Monitoring power plant performance
Three performance-monitoring procedures available to utility enginers are discussed in this paper: energy accounting, testing of power plant components, and continuous display of controllable parameters. The paper also discusses utilizing performance analysis to link steady state models of a plant with a dynamic model. Dynamic analysis can also be used to simulate sudden upset conditions to see how the plant behaves. It also provides a new level of insight into steady-state operation.
Heat Transfer Analysis in Cooling System of Hydropower’s Generator
Cooling process of power plant generator is handled via air-cooled radiators in which the cooling water is supplied from lake with its water temperature varies from season to season. In this study, the effect of temperature fluctuations of cooling water entering the cooling system has been examined via analysis of energy (NTU method) and exergy. The exergy analysis has been done by definition of efficiency coefficient for exergy of cooling media (water) and heating media (air). Besides, the effect of changing the cooling water temperature and flow rate entering the radiators on the cooling system performance has been studied. The results revealed the generator cooling system performance level held sufficient till the temperature of inlet water was kept under 293 k (20°C). On one hand, when the temperature of cooling water at the inlet rises to 12°C, the rate of heat exchange at radiators falls up to 34.3%. On the other hand, by water temperature passing the 12°C limit, the efficiency of cooling media exergy falls to 78% leading to efficiency rise in radiators’ heating media exergy level to 61%. According to the results of this study, changing flow rate of cooling media up to 40% gives rise to the efficiency coefficient of radiators’ cooling media exergy level to about 18.7%. While it does not affect the efficiency level of energy at radiators, the flow rate rise of cooling media may not be considered as a way to give rise to efficiency level of radiators.