Exergetic Systems, Inc.-- Performance Monitoring: Input/Loss Method- Direct Testing

Input/Loss Method - Direct Testing

Direct testing of computed heating values is, at best, a difficult task when burning coal; and especially if burning a highly variable coal such as from the Powder River Basin (PRB) or lignite. Although such testing work continues, Exergetic Systems believes that secondary indications of computed heating value serve equally well. These indications are trends in the plant's fuel flow and/or combustion air flow. Industrial experience with emission flows would indicate the measurements are biased, and unreliable even for trending. However, at every installation of Input/Loss, engineers quickly develop sanity checks as to monitoring performance, and generally based on trended flow rates. The bases for such sanity checks stems from Input/Loss' computational consistency.

Periodically, a power plant will conduct test burns of different coals, which affords an opportunity for direct comparisons. Such an example is provided above. Further, Exergetic Systems has proposed to the power industry several new methods of qualifying on-line monitoring systems. These new methods include comparisons to the unit's Energy Compensator, to a computed soot blowing flow, to a computed relative humidity, etc.