Analysis of Performance of Ljungstrom Air Preheater Elements

Abstract

Special Issue-2, (February 2014) Abstract The Ljungström air pre-heater is a regenerative type of heat exchanger used for preheating the combustion air, mainly in thermal power plant. The warm gas and cool air ducts are arranged to allow both the flue gas and the inlet air to flow simultaneously through the air preheater. The hot flue gas heats the rotor material and as the rotor rotates, the hot rotor section moves into the flow of the cold air and preheats it. The performance of Ljungstrom Air Preheater is depended on the heat transfer element profiles. New profiles are being designed in such a way that these new profile elements must be improving the efficiency of Air Preheater. In this context, it is felt necessary to develop new element profiles with lesser pressure drops for efficient heat transfer with less power consumption to improve overall efficiency of thermal power plants. In this research paper, two types of element profile (Flat Notched Crossed & Double Undulated elements) are tested using cold flow studies with the help of wind tunnel and compared their performance at different Reynolds numbers.