Cogeneration systems are extensively used in Malaysia to produce power as a primary
source. However, in the event of cogeneration system failure, the customer or the client are
forced to use a redundancy to avoid power interruptions. There are two methods commonly
used as a backup in the cogeneration systems which are Generator set and public utility. In
order to choose the best redundancy for a particular cogeneration system, it is essential to
evaluate the economic benefit analysis by considering several factors such as Maximum
demand charge, installation cost and Discount interest. In the evaluation of economic
benefit, this study identifies the number of failure and associated downtime using reliability
and availability approach, and then present value method was applied. The result shows
that the usage of public utility as redundancy is beneficial if the cogeneration system
operates within five years period. However, if the cogeneration system operates more than
five years, generator set option would be a better option to minimize the total cost. This
research also addresses the effect of various factors such as installation cost, maximum
demand charge, fuel cost, discount interest rate and production capacity. In general, the
output of the research would be beneficial for the plant operator to select the appropriate
redundancy option based on the economic advantages.
Heat exchangers are used in many industries and power generation applications. The performance of heat exchangers depends on the operating parameters and the types of flow. The sudden pressure drop is one of the major problems encountered in heat exchanger, and this would significantly affect the efficiency and the overall heat transfer coefficient of the heat exchanger. Therefore, this study is aimed at investigating and analyzing the effects of operating parameters that cause pressure fluctuation and affect the overall heat transfer coefficient. Experimental study was carried out for two types of flows: co-current and counter concurrent flows. Comparisons of the overall heat transfer coefficients between shell and tube and spiral coil heat exchangers were made. It was observed that mass flow rate affected the overall heat transfer coefficient. Besides, the counter current flow was more efficient compared to the co-current flow with enhanced overall heat transfer coefficient. The maximum overall heat transfer coefficient for spiral coil heat exchanger counter flow was 2702.78 W/m2.K, showing a higher heat transfer efficiency when compared to the shell and tube heat exchanger. Moreover, the spiral coil heat exchanger occupied less space as opposed to the shell and tube heat exchanger.