ABSTRACT
It is generally recognized that considerable energy savings could result from installing a waste heat recovery system in the exhaust of a Gas Turbine power plant. The present study proposes to use that recovered heat to supply heat to an absorption refrigeration system (ARS). Various sources and levels of extracted heat loads from exhaust gases were studied for possible utilization with the (ARS). Typical waste heat available loads were found to be in the range of 58-62% of the heat supplied to a frame 7 Gas Turbine unit. A comparative study of the Water-Multi component Salt Mixture, the conventional Water Ammonia and the Water-Lithium bromide systems was carried out for both single-stage and double-effect absorption cycles. The results showed that the Coefficient of Performance (C.O.P) is higher for Water-MCS mixture than that of the Water-LiBr solution. Water-MCS mixture can also be used for a wide range of operating loads and conditions; therefore it is suitable for use in absorption refrigeration systems associated with variable load waste heat sources. Water-MCS mixture is approximately five times cheaper than LiBr, which makes the cooling system more economical. A laboratory experiment for a simple single-stage absorption system utilizing the Water-MCS mixture was constructed and operated. The system was tested to determine the thermal performance under variable operating conditions. Actual system C.O.P. values were found to follow the theoretical analysis trend but with less values.
CHAPTER ONE
1.0 INTRODUCTION
1.1 BACKGROUND TO THE STUDY
Maritime transport is a huge energy-consuming sector globally. Typically onboard energy is produced using diesel engine combustion. This power is used for propulsion and to generate electricity that is needed onboard. However, environmental and economic concerns have caused the maritime sector to explore alternative solutions in order to improve the efficiency of the energy usage system and to reduce their emissions. Diesel engine combustion produces pollutants like SOx and NOx [1]. Approximately 3.3% of global CO2 emissions are caused by shipping. The International Maritime Organization is the major global regulator for emissions in maritime transport. Moreover, the European Union has implemented a directive for sulfur emissions in specific control areas. These factors and the fact that the prices of fossil fuels are rising continuously have motivated the marine sector to reduce its fuel consumption [2]. Baldi and Gabrielii [3] described a methodology for performing a feasibility analysis of the installation of a waste heat recovery (WHR) system on a vessel. The method based on available data from ship operational profile. The various types of WHR technologies available on board ships were discussed from the perspective of technological principle and application feasibility by Shu et al. [4]. The focus was to provide a better understanding of the options available for WHR in order to improve fuel economy and environmental compliance.
