LPP - Lean-Premixed-Prevaporized Combustion
The LPP (Lean Premixed Prevaporised) test rig, at DLR Köln-porz is designed to operate under high pressure, temperature and velocity conditions, approximating the values found in actual gas turbine combustion systems. The Test rig is fully equipped to perform the measurements on sprays and mixing of air and fuel, under non-reactive conditions.
The test cell of the LPP test rig is made of high strength alloy steel with 3 window optical access for flow visualisation and measurements.A cross sectional view of the test cell is shown in the Figure below. The test cell has two channels, an inner channel or premixing duct made of quartz glass, which can handle high temperatures, and the outer channel to provide cooling air for the inner channel so that only temperature loading is on the inner quartz channel. The differential static pressures between the inner channel and the ambient air is resisted by pressure windows of the outer channel, made of glass. The mass fluxes in the inner channel and cooling air can be seperately regulated. The pressure and velocity in the inner channel can be independently controlled by varying the air mass fluxes in the two channels.
The maximum working conditions at which the test rig can be operated are:
The central air reservoirs (with 60 bar pressure pipeline) provide continuous supply of air. The test rig can be operated continuously, for any length of time. The operation of the test rig is automated. To abide by the emission norms, a catalisator has been installed to decompose the hydrocarbon fuels present in the working fluid from the test section outlet.
Real aviation fuel:
Tests are run using the prevalent aviation fuel kerosene Jet A-1, ensuring realistic atomization and evaporation characteristics.