Efficiency Measurements
Stone Creek Testing
This
project, consisting of one five-jet impulse turbine, was developed by an
independent power producer (IPP) and put up for sale. In order to
accurately evaluate the long-term generation revenue stream, overall plant
efficiency needed to be determined before the buyer and seller could agree on
final price.
Devine Tarbell & Associates, Inc.’s (DTA) was retained to perform a thermodynamic efficiency test in accordance with IEC code 41. In addition to the efficiency test, the penstock headloss was determined. The flow discharge per jet versus needle stroke and Pitot velocity measurements were also determined for comparison with previous test results.
DTA staff completed the thermodynamic efficiency testing was accomplished with a measurement uncertainty of less than +/-1.2 percent. Head loss of the penstock was measured, and the head loss coefficient was calculated. The position of each nozzle was recorded at each test point and flow discharge per jet versus needle stroke was checked. The Pitot probe at the turbine inlet was used to measure point velocity. Test results were compared with calibrated point velocity head/flow discharge ratio from earlier tests. Both seller and buyer accepted the test results and successfully concluded sale negotiations.