Optimal flue gas cooling in small plants for combustion of biomass and domestic fuel oil

The project deals with the convection part of small boilers for firing with wood or boilers for domestic fuel oil. Modern burner technology allows for higher velocities and for higher pressure drops in boilers. At the same time the machining of boilers to day is of high precision and the boilers are sealed totally. This means, that - from a safety point of view- the flue gas heat exchangers can be designed to a much higher pressure loss. The project deals with heat exchangers, that easily can be cleaned and is concentrated on flow inside tubes and channels. The project includes. -Investigation of different inserts in different cross-sections -Investigation of different internal ribs and fins inside tubes -Investigations of varying the cross section along the length of the pipe. -Investigation of inlet and outlet pressure drop The methods used will be calorimetric measurements in water cooled channels with hot air, cold air or with flue gas. Measurements on heat exchangers integrated in complete boilers. Further- if necessary - laser sheet visualisation and cfd calculations will used on details