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.
Life management of high-temperature piping and tubing in fossil power plants
Aging of power plants and competitive pressures to operate and maintain (O&M) these plants at reduced costs have heightened industry interest in life assessment and management technologies. Piping and tubing systems carrying high-pressure steam at temperatures exceeding 1000°F (530°C) have notably been the center of focus of many of these activities. Enormous progress has been made in understanding mechanisms of damage and their rate of evolution. Progressive application of improved calculational, nondestructive and destructive techniques have enabled optimum utilization of components at reduced costs. In addition, the efficacy of weld repair techniques to extend the lives of aged components has been investigated in detail. This paper will review the damage mechanisms encountered in fossil power plant boiler pressure parts and then describe in more detail life management tools that have been developed.
Experimental Study for a Double-Glazed Forced-Flow Solar Collector/Regenerator
Experimental study of a double-glazed forced-convection solar collector/regenerator for absorption solar cooling is presented. The south facing experimental solar collector/regenerator with 10 deg slope is located at Kaohsiung, Taiwan at 120{degree}19minutesE longitude and 22{degree}34minutesN latitude. The size of the collector is 1 m wide and 7 m long with an effective regeneration area of 0.9 m by 6 m. Previous study for single-glazed forced-convection solar collector/regenerator operated at the same location has shown to have a best day-average efficiency of 17%. In order to raise the system performance, a double-glazed collector/regenerator is constructed such that air can be preheated in the upper channel flow. The preheated air is then conducted into the lower channel where it contacts with the film flow of solar heated lithium-chloride solution and regenerates the solution by carrying out the evaporated water vapor. The preheated air has lower relative humidity but the same humidity ratio since it is sensibly heated. Therefore, the regeneration driving potential is increased. The present study shows that the best day-average efficiency can reach 20% which increases the feasibility of the open-cycle absorption solar cooling system. Effects of controlling parameters on the collector/regenerator performance are studied, and heat and mass transfer correlationsmore » are also presented for design purposes.« less