Under controlled conditions, combustion tests of middle distillates in commercially available low-temperature and condensing boilers allow the investigation of fuel-related deposits on burner components and surfaces that can impair thermal performance. In two boilers operated in parallel – from low-temperature to condensing boilers – the formation of increased deposits on burner surfaces, nozzles, fuel preheaters and pumps can be identified and evaluated in long-term operation. The boiler efficiency is measured at intervals during the test.
The combustion test and the ageing test can be combined with each other. By integrating components such as nozzle, preheater and pump, which were used in the ageing test, into the boiler of the combustion test and by using the pre-aged fuels for the test, interactions between fuel and technical components can also be detected during the combustion process.