Variation in rheological properties of engine oil with usage

The variation in the rheological properties of engine oil with usage was examined in this study. The parameters considered include: the kinematics viscosity, viscosity index and specific gravity. These properties of lubricating oil tend to degrade in quality with usage. This study gives a relationship between the stated properties and distance covered for a commonly used car in Nigeria (fairly used Honda Accord of 1988 model). The relationship so obtained is represented in the form of a linearized model to enhance prediction. Keywords: Rheology, viscosity, friction and lubrication. [Global Jnl Engineering Res. Vol.2(1&2) 2003: 95-100

Performance evaluation of a combined cycle power plant integrated with organic Rankine cycle and absorption refrigeration system

This study presents the performance evaluation of a combined gas- and steam- turbine cycle power plant (CCPP) integrated with organic Rankine cycle (ORC) and absorption refrigeration cycle (ARC). The attached ORC and ARC units are powered with the flue gas exhaust heat from the CCPP. The evaluation was conducted by performing energy, exergy and environmental sustainability index analysis of the integrated power plant (IPP) and its components. Based on the operating data of an existing CCPP operating in the tropical rain forest region of Nigeria, results of the analysis showed that by utilizing exhaust heat of the CCPP to power an ORC, using R113 as the working fluid, extra 7.5 MW of electricity was generated and by powering an ARC to cool inlet air streams to 15°C in the gas turbine plants, additional 51.1 MW of electricity was generated. The overall effect of integrating ORC and ARC to the CCPP showed that the net power output of the integrated power plant was increased by 9.1%, thermal and exergy efficiencies by 8.7% and 8.8%, respectively, while the total exergy destruction rate and specific fuel consumption reduced by 13.3% and 8.4% respectively. Sustainability index increased by 8.4% which means that the integrated plant has greater environmental sustainability potential over the combined cycle plant