ASSIGNMENT CHM 458 CHEMICAL THERMODYNAMICS AS225 PART II 2012/2013TITTLE : HEAT ENGINENAME : NURUL SABIRAH BINTI MOHD SALEHI/D : 2011581687LECTURER : DR MD NOOR BIN ZAKARIADATE SUBMIT : 27 DECEMBER 2012
INTRODUCTION TO ZEROTH LAW,FIRST ,SECOND ,AND THIRD LAW OF THERMODYNAMICSZEROTH LAWThe zeroth law states that if two systems are in thermal equilibrium with a third system, they arealso in thermal equilibrium with each other.It can also be defined as that if two systems, A and B,are in thermal equilibrium with a third system, C, then A and B are in thermal equilibrium with each other.FIRST LAW OF THERMODYNAMICSFirst law of thermodynamics state that energy cannot be destroyed or created.It shows theprinciples of conservation of energy.SECOND LAW OF THERMODYNAMICSSecond law of thermodynamics state that the entropy of an isolated system never decreases,because isolated systems spontaneously evolve towards thermodynamic equilibrium.THIRD LAW OF THERMODYNAMICSThe third law of thermodynamics is stated as the entropy of a perfect crystal at absolute zeroKelvin is exactly equal to zero.Now what I am going to do in this assignment is based on these 4 laws of thermodynamics.I’musing my own car engine to be a model for the heat engine.I have study all 4 laws and I am goingto relate them to my car’s engine.The type of engine that I am using is 1.3 litre K3-VE engine with four in-line cylinders; bothengines employ Dynamic Variable Valve Timing (DVVT) systems and conventional electronicfuel injection (EFI).
Hot air region or This is an overview of outer part of enginehot reservoir at Th Engine This is what happened in the cold reservoir, Th Heat engine is a system that performs the conversion of heat or thermal energy to mechanical work. It does this by bringing a working substance from a high temperature state to a lower temperature state. A heat "source" generates thermal energy that brings the working substance to the high temperature state. Carnot Cycle occur here (1st law of thermodynamics)
HOW I RELATE THOSE LAWS IN THE CAR ENGINEFOR FIRST LAW-CARNOT CYCLECarnot heat engine consists of 5 main parts that is cylinder,source,sink,working substance and aninsulating pad.Cylinder,which is the main part of the carnet engine has insulating walls and conductingbase.It is suited with a perfectly insulated and frictionless piston.Source,the source is a very hot bodymaintain at a peaks higher temperature and has infinite thermal capacity.By infinite thermal capacity wemean that any amount of heat can be taken out of it withut changing the temperature of thesource.Sink,is a body at low temperature, T2 also has infinite thermal capacity that is any amount ofheat can be added to it without changing its temperature.Working substance,it is the ideal gas whichabsorb heat from the source,does some mechanical work and recheck the remaining amount of heatinto the sink.Insulating pad or insulating stand,during the operation the Carnot cycle,working substancesundergo adiabatic expansion and adiabatic compression.The cylinder is placed on insulating pad whichis thermally isolated working substance from the surrounding.To continue supply work,the workingsubstance is taken to the series of operating system called the Carnot cycle.The Carnot cycle consist oftwo reversible isothermal and adiabatic processes.Carnot Cycle is obtain when ideal gas is used as theworking substance.The ideal gas is taken inside the cylinder to the piston.FOR SECOND LAWSecond law gives the direction of the heat flow that are from hot region which is high energy to coldregion which is low energy.Heat energy is never completely converted to mechanical energy that isefficiency of the heat engine is never equal to 100%.Efficiency of an engine can be defined as the ratio ofexternal work done to the amount of heat absorbed from the source.There are two types of enginewhich is external combustion engine and internal combustion engine.For this car engine is internalpetrol engine.Heat flow from hot reservoir to cold reservoir.This is how second law is applied.FOR THIRD LAWIn heat engine,third law is applied when