Efficiency and energy losses for combi boilers

In this thesis study, the potential for efficiency improvement methods for gas-fired combi boilers are investigated. Efficiency and energy losses are experimentally determined, while the performance of a gas-fired combi boiler is evaluated using energy and exergy analysis. This thesis consists of mainly five chapters. In the first chapter, main description and contribution of the gas-fired combi boilers for domestic and commercial in the overall energy balance worldwide are given. The second chapter includes a classification of the combi boilers according to different categories, while main components of room sealed flue combi boiler are briefly explained. In the following chapter, efficiency measurement techniques based on the related standards, detailed combustion equations, exergy analysis and energy loss sources are examined. A brief description of condensing boilers and the state of the technological improvement for these boilers are also presented. The fourth chapter contains experimental studies on efficiency and energy losses, which have been performed at the laboratories of Bosch Heating Systems Research and Development department, in Manisa. In the last chapter; the test results obtained are assessed, while main topics of the thesis are given briefly. Average energy and exergy efficiency values for the combi boilers studied are found to be 91 and 13.6 of percentage, respectively.