estimating said cooling amount, based on an estimation result of said fuel cell, when {HEAD ~ the step} of detecting the temperature of {TAIL ~ said refrigerant} malfunctions 
estimating said cooling amount , based on an estimation result of said fuel cell , when { HEAD ~ the step } of detecting the temperature of { TAIL ~ said refrigerant } malfunctions
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH