High-Temperature-Turbine Technology Program, Phase II: Technology Test and Support Studies. Low-Pressure Rig Engine Test Program

摘要

The objective of the LP rig engine test program was to evaluate the durability of a transpiration air-cooled turbine component operating in a 2600 exp 0 F to 3000 exp 0 F gas stream laden with particulates simulating the aggressive environment created by the combustion of coal-derived low Btu gas. Of particular concern, in addition to thermal effects, were the possibilities of corrosion, erosion and deposition by the gas stream contaminants. Over 800 h of LP rig engine testing was completed. This included more than 700 h at a turbine inlet temperature of 2600 exp 0 F and above, and over 650 h with hot gas stream particulates. Transpiration air cooling was shown to be particularly effective in maintaining satisfactory metal temperatures, even under conditions of significant foreign object damage. Airfoil skin oxidation was minimal. At the specified particulate size range and loading, there was no evidence of sulfidation, corrosion or erosion. Some light deposition of particulates was encountered, but this produced only a slight reduction in porous skin cooling airflow capacity and had no measurable effect on turbine performance. The rate of transpiration skin cooling flow capacity loss with operating time in the particulate-laden gas stream was found to be similar to that which occurs by oxidation alone. In both cases the rate of loss decreases with operating time and appears to approach zero after several hundred hours of operation. The LP rig engine test program was preceded by a combustor development program and stationary turbine vane cascade testing. The former program established the combustor and particulate injection arrangements for the LP rig engine test. The turbine cascade program produced transpiration skin test results similar to those of the LP rig engine, even though these tests were conducted at significantly higher levels of particulate loading. (ERA citation 07:007133)