QUESTION 1 (35 points) Natural Gas with Flame Temperature 2235 K TH=283 K a- b- Stack Temperature 650 K 320 K 300 K District Energy System 10 points Draw the exergy flow bar of this power plant (without the district energy system) Calculate the destroyed exergy between the stack temperature and natural gas flame temperature 10 points Calculate the REMM efficiency, R 10 points 5 points d- Is this a green power plant? explain very shortly (Hint: Compare with 0.70)​