若标煤为每吨1200元,标煤热值7000kcal/kg,锅炉热效率为60%,假如锅炉所获热量10%转化成电能,其余转化为蒸汽,以0.44元每度电作价,每公斤蒸汽热量为500kcal,则蒸汽成本为()元。
A. (1200-(7000*60/100*1000*10/100*4.2/3600)*0.44)/(7000*60/100*(100-10)/100/500)
B. 1200/(7000*1000*60/100*4.2/3600)
C. 1200/(7000*60/100*4.2/3600)
D. 1200-(7000*60/100*1000*10/100*4.2/3600)*0.44/(7000*60/100*(100-10)/100/500)