06-11-2014, 09:42 AM
Abstracts: This project deals with recovering of a waste heat recovery system at an ESSAR STEEL LTD. in Hazira, to recover waste heat from exhaust gases of blast furnace that is currently being let out to the atmosphere at a temperature of230°Caftercomplete process heating.This gases are needed to cooled down to temperature about 85°Cto 90°Cbefore entering FES(fumes extraction system) as per emission norms. Currently, this is achieved with the help of finned type heat exchanger(air cooled) placed before FES(fumes extraction system).so , the heat exchanged between air and exhaust gases is directly decapitated in atmosphere which is going to waste. So , there is a need to replace the system by other waste heat recovery unit This waste heat is then used to produce hotwater by using waste heat recovery equipment i.e. shell and tube heat exchanger. Also there in Chiller plant at Utility Department, One refrigeration unit VAMof 500TR capacity running on vapour absorption refrigeration cycle. Vapour absorption machine (VAM) requires hot water to run the cycle. Due to insufficient supply of hot water, that VAM unit is not in working for three days in a week. During this period the optional refrigeration unit VCR of same capacity 500TR which is running on conventional vapour compression cycle is used for same application. This VCR unit consumes large amount of energy (350kw/hr) compared to VAM unit which consumes only 11kw/hr. so, it should be replaced by some efficient & low energy consuming refrigeration device like Vapour Absorption Machine. High power consuming vapour compressor refrigeration (VCR) unit can be replaced by more energy efficient vapour absorption machine (VAM) which is running on vapour absorption refrigeration cycle. Vapour absorption machine (VAM) requires hot water to run the cycle. so, the hot water obtained from shell and tube heat exchanger is further utilized in vapour absorption machine. Thus, Vapour absorption machine consumes only 11 kw/hr of energy for same capacity of 500 TR. So, Vapour compression unit should be replaced with vapour absorption machine.