Prediction of system-level emissions performance via equipment shelf primary power bus frequency response characteristics
This paper reports an interesting extension of the frequency response testing technique to characterize real-world EMC conditions as encountered in the Product Realization cycle. It is demonstrated that the behavior of the Primary Power Bus of a system Equipment Shelf is a reliable predictor of the system’s EMC performance. In particular, the Conducted and Radiated Emissions characteristics of the system are anticipated before the system is fully assembled, and long before System-Level formal compliance testing is done. The frequency pass-bands and resonances of the Primary Power Bus are identified and these outcomes are closely correlated with independently obtained Conducted and Radiated Emissions spectra for the populated system Equipment Shelf.
A Hierarchical Model for Prescribing EMC Design Targets to the Components of a System
Components of a system (i.e., Units, Shelves, or Modules) cannot meaningfully be tested for system-level emissions compliance by themselves. The lack of EMC Design objectives for emissions at the sub-system level makes it ambiguous for component designers to decide whether a given component design is EMC-sufficient. This paper introduces and discusses a qualitative methodology for defining practical EMC design targets for the components of a System for production purposes. This is a preliminary step in attempting to address this need, using a combination of common-sense, stand-alone component- level emissions testing strategy and periodic design reviews of components during their design cycle.
Full-scale measurements of SO2 gas phase concentrations and slurry compositions in a wet flue gas desulphurisation spray absorber
Abstract Two measurement campaigns were carried out at ENERGI E2's Asnaes Power plant, unit 5. The unit has a capacity of 620 MW e and is equipped with a wet flue gas desulphurisation (FGD) plant employing a counter-current spray absorber with five spray levels. In the first campaign, the power plant was firing Orimulsion ® with 2.85 wt% S resulting in a flue gas concentration of SO 2 exceeding 2000 ppmv. In the second campaign, the fuel applied was a low-S blended coal and the SO 2 concentration in the raw gas was around 400 ppmv. A novel probe for in situ sampling of gas phase concentrations in wet FGD spray absorbers was developed and applied for measuring axial profiles of the SO 2 gas phase concentrations in the absorber. The expected decrease in SO 2 concentrations along the height of the absorber was found in the spray section (from height 26.5 to 36.2 m) whereas the SO 2 concentration above the holding tank and below the gas inlet was quite low probably due to long local residence times in the region. Horizontal variations, due to somewhat different flow conditions near the column wall were investigated and the SO 2 concentrations were found to be higher near the wall. Measurements at different gross loads showed that the SO 2 gas phase concentration at a given position inside the absorber was roughly linearly related to the L/G ratio in the measuring interval. Turning off one of the lower spray levels, while burning coal with low S content, did not lower the overall removal efficiency of the absorber. However, the SO 2 gas phase concentration inside the lower part of the absorber was increased by a factor of 2–3. Measurements of slurry pH at different positions showed a decrease of approximately 0.5 units from the upper to the lower part of the absorber. The full-scale measurements provide a detailed set of experimental data for validation of mathematical models of a wet FGD spray absorber.