簡述發(fā)熱量的測定原理并根據(jù)某電廠入廠煤化驗結(jié)果計算空氣干燥基高位及收到基低位發(fā)熱量各是多少? Mar= 6.5% , Mad = 2.00% , Had =3.00 %, Sb,ad =1.50% , Qb,ad =20072 J/g , Aad =45.50 %。