Compress natural gas (CNG) is also considered as alternative fuel to produce better emission in a vehicle, but the main disadvantage of CNG in comparison to liquid fuel (gasoline) is the lack of power produced for the same capacity of engine. In this study, the single cylinder spark ignition (SI) engine was selected in order to study the effect CNG into the spark ignition engine. The hydraulic dynamometer was used to study the performance of CNG and liquid fuel. The usage of sensor also applies to the test to extract the data during the ignition stage for liquid fuel and CNG. The heat generated by both types of fuel also had been extracted from the tested engine in order to define which usage of fuel would cause a higher heat transfer to the engine. From this study, the result showed that pressure inside cylinder for CNG is 20% less than gasoline. CNG fuel also produced 23% less heat transfer rate compared to gasoline. The results explained why CNG produced 18.5% lower power compared to liquid fuel (gasoline).So, some improvement needs to be done in order to use CNG as fuel.

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A simple algorithm to simulate the transient behaviour of a vapour compression heat pump is described. Individual models are developed for various components of the heat pump such as compressor, evaporator, condenser and expansion valve. The components are simulated separately and are combined to form the total system. The compressor is a hermetically sealed, reciprocating piston type with adiabatic compression, the evaporator and condenser are coiled copper tubes, and the expansion valve is assumed to be adiabatic. The transport and thermodynamic properties of the refrigerant used are obtained from empirical equations. The total system is viewed in a simplified manner in order to apply the results of this transient analysis to the behaviour of a chemical process operation, namely, distillation. KEY WORDS Heat pumpHeat pump assisted distillation Transient analysis Simulation

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