Consider the following information of an industrial boiler test:

Based on the previous data and the following expression, estimate the energy efficiency of the tested boiler.

- Duration of test: 1 hour Steam produced by boiler: 200,000 lbm Temperature and pressure of steam: 760F, 600 psia Temperature and pressure of feed water: 240F, 700 psia Fuel used (coal): 15,385 lbm @ 80F, dry (HHV: 19,500 BTU/lbm of dry fuel) Temperature of combustion gases in the last heat recovery step: 450F T db and Two of combustion air: 80F and 70F Barometric pressure at the test site: 29.92 in Hg wb {Enegy absorbed by water} = {Energy input in fuel} - mwater (hsteam hliq) = mfuelHHVfuel