Chapter 5, Problem 5.8E

Thermodynamics. 1) For a closed system, as the exergy reference environment temperature ___________, the exergy destruction rate decreases 2) Which of the following statements does not describe the exergy reference environment? It is large in extent. It has a uniform temperature. It is incompressible. It has a uniform pressure.   3) Air within a piston–cylinder assembly undergoes an expansion process from an initial volume of 0.5 m3 to 1 m3. The dead state pressure is 100 kPa. If the work associated with the process is 60 kJ, determine the exergy transfer accompanying work, in kJ.

Given the volumetric analysis of a gaseous fuel is given CO2 = 2.7% CH4 = 64.5% N2 = 1.7% C2H2 = 33.5%    Calculate:   O/F ratio by volume   O/F ratio by mass   A/F ratio by volume   A/F ratio by mass   Volumetric Analysis of flue gas @ 30% excess   %V CO2 =   %V O2 =    %VN2 = %V H2O =

Which of the following is the correct statement?   a. Irreversible engines have maximum efficiency   b. The increase in entropy is obtained from a given quantity of heat at a low temperature   c. The entropy represents a maximum amount of work obtainable per degree drop in temperature   d. All the reversible engines have the same efficiency   e. All the reversible and irreversible engines have the same efficiency   f. The change in entropy may be regarded as a measure of the rate of the availability of heat for transformation into work   g. All engines are designed as reversible to obtain maximum efficiency

Volatile liquid fuels behave differently from gaseous fuels. Make 10 sentences specifying these differences.

An aircraft engine produces (1.4800x10^2) kW power in normal idle mode. If the fuel flow rate is (3.07x10^0) kg/min, find its specific fuel consumption (sfc). The answer should be in g/kWh with three significant figures. Note: Your answer is assumed to be reduced to the highest power possible. Your Answer: x10

The fuel efficiency for Vehicle 1 is modelled by A(t) = t+4 / t+2, and vehicle 2, by A(t) = t-2/ t-4. At what operating time(s) will Vehicle 1 have a lower fuel efficiency than Vehicle 2?

Question: Please explain why your car engine is generally less efficient when its ignition temperature is lower. *Please be thorough with the answer.

Exercise 7 7.1 A sample of coal gave the following analysis by mass: C 81.9%; H2 4.9%; O2 6%; N2 2.3%; ash 4.9%. Calculate: 7.1.1 the stoichiometric air/fuel ratio (10.8/1); 7.1.2 the analysis by volume of the wet and dry products of combustion when the air supplied is 25% in excess of that required for complete combustion (CO2 14.16%, H2O 5.07%, O2 4.04%, N2 76.7%, CO2 14.9%, O2 4.24%, N2 80.9%).

In a nutshell Give four advantages and disadvantages of using and handling solid fuels as compared to liquid and gaseous fuels. Advantages 1. 2. 3. 4. Disadvantages 1. 2. 3. 4.