The Cooling Technology Institute (CTI) has recently announced the release of ATC-105DS, a new test code for air cooled fluid coolers, more commonly referred to as dry coolers. This newly published dry cooling supplement is an addendum to the ATC-105 Acceptance Test Code for Wet Cooling Towers. The supplement for dry cooling specifies the measurement of inlet dry-bulb temperature for the dry cooler under test as opposed to inlet wet-bulb temperature, which is required for evaporative (wet) towers. Since dry fluid coolers frequently use a solution of glycol as the process fluid, the supplement also provides a method for correcting for the thermodynamic properties of the process fluid. Like an evaporative cooling tower, the dry cooler is tested as a unit, inclusive of the fan. In contrast with ASME PTC-30, airflow rate measurements are not required, which makes it practical to test multiple fan units. The major parameters required for the test method specified by the dry supplement are: Process fluid flow Process fluid inlet temperature Process fluid outlet temperature Process fluid composition Inlet dry bulb temperature Fan motor power The number and placement of dry bulb temperature sensors are based on the air inlet cross sectional area in the same manner as wet bulb temperature sensors are configured for a wet cooling tower. The CTI Press Release from last September includes a link that allows you to purchase the new supplement as well as other CTI standards, codes, and guidelines. As one of the CTI licensed test agents for cooling towers, CleanAir has decades of experience in testing cooling towers, closed circuit cooling towers, and air-cooled condensers. This experience allows CleanAir to plan and conduct acceptance tests of all types of heat rejection equipment, including dry fluid coolers, with the high accuracy required by the test codes, while minimizing costs.
There are many reasons to conduct a gas turbine performance test, including determining compliance with acceptance guarantees, establishing benchmarks for performance monitoring and power purchase agreements, and determining performance parameter corrections. Regardless of the reason, these test results need to be both reliable and defendable in order to make sound decisions. CleanAir recently gave a presentation on gas turbine performance testing at the Western Turbine Users conference (WTUI). The presentation included information on gas turbine performance testing preparation, execution, instrumentation, correction methodology, and test uncertainty analysis. Gas turbine performance test results are typically corrected to a reference condition for comparison to guarantees or for comparison to previous test results as part of a performance monitoring plan. The presentation begins with the recommended preparations and provides a high level overview of the basic test measurements and the common corrections that are applied to test results in order to calculate corrected gas turbine performance. A pre-test uncertainty analysis is often completed to identify the most important test measurements that influence corrected gas turbine performance, which helps in the selection of appropriate test instrumentation. A post-test uncertainty analysis calculates the uncertainty of the corrected gas turbine performance based on the actual test conditions. The presentation concludes with a comparison of the corrected gas turbine performance uncertainty using typical station instrumentation versus typical precision test instrumentation. If you are in need of reliable, defensible performance data for internal benchmark testing, contractual acceptance, or even for dispatching, this presentation should help you feel more confident you are getting the best data possible. If you would like a copy of the full presentation, please click here. Generating Reliable Gas Turbine Performance Data