Experimental study of the ozone as an anti-fouling system in an exhaust gas heat exchanger

• Ozone was studied as an antifouling system in parallel to fouling generation. • Different ozone injection points and gas temperatures were tested in a real system. • Ozone produces a thermal efficiency increase of more than 4 points in 8 h. • THC concentration is reduced by 6 to 10 times by the effect of ozone. • Ozone injection improves the head loss under certain temperature conditions. Fouling generated in combustion systems and their auxiliary elements is a problem of interest for transportation engineering and all areas of application of combustion systems. In this work, the use of ozone as a system to minimize or eliminate fouling on the elements that make up a combustion system and the effect on the exhaust gas stream was experimentally analyzed. To carry out the experiments, a fouling generation test bench was used, to which an autonomous ozone injection system was coupled. Tests were performed under controlled conditions to characterize the generated stream and fouling. The tests were carried out at different exhaust gas temperatures and at different injection points, under conditions close to real conditions. These tests made it possible to analyze the effect of temperature and position of ozone injection on fouling and gas flow, compared to equivalent tests without ozone injection. The changes produced by ozone injection on fouling were analyzed based on thermal efficiency, head loss and deposited mass. Furthermore, THC, opacity, CO, CO 2 , O 2 , NO and particle distribution were measured to study the changes in the exhaust gas. Ozone injection produces an increase in thermal efficiency of more than 4 units after 8 h. The head loss showed different effects depending on the temperature, decreased by more than 10 % for the 140 °C tests and increased by more than 10 % for the 180 °C tests. In the gas stream, THC concentration decreased by 6–10 times and CO concentration increased by more than 30 %.