Calculate the boiler efficiency of a boiler with the following operating data. fuel ultimate analysis (wt%): c=71.81, h=5.23, 0=10.15, n=1.2, s=3.34, ash=8.27. fuel hhv=13,082 btu/lb flue gas analysis (vol%): co2=14.2, co=0.3, 02=4.3, n2=81.2. refuse: w_r=0.115 lb/lb of coal burned flue gas temperature = 300°f ambient temperature = 85°f ambient relative humidity = 50%

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.