Commercial Boiler Waste-Heat Utilization for Air Conditioning in Developing Countries

Abstract

This study investigates the utilization of waste heat from commercial process steam boilers for air conditioning using absorption cooling systems. An ammonia-water generator absorber heat exchange system was developed and modeled to use waste heat from the boiler flue gases and deliver chilled water. Based on approximately 1000 process steam boilers at an average throughput of 2000 kg/h in one metropolitan area in India, the study estimates that installation of these systems could result in annual operating cost savings of $10,200,000 in this region alone. These 1000 systems would also reduce the installed electric capacity needs by 16 MW. Annual coal consumption would decrease by 87,000 tonnes, while ash production would decrease by 39,000 tonnes. Carbon-based emissions are estimated to decrease by 176,000 tonnes. Therefore, installation of these systems on a countrywide basis and also in other developing countries with high year-round cooling loads and coal-based power generation would significantly alleviate installed power capacity shortages, conserve energy resources, and reduce greenhouse gas emissions.