Technical, economic, and environmental analyses of CCHP systems with waste incineration power plant as prime mover

Abstract

ABSTRACT In recent years, population growth and community development have increased the volume of waste in many parts of the world, including in Iran. If management measures are not taken to reduce the volume of waste at the surface, the problem of increasing waste will become a major and serious threat to human life. Therefore, incineration plants will be built to reduce the volume of waste, which have potential to generate power. Accordingly, the purpose of the present study is potential analysis of exhaust gases from the incineration plant for use in the combined cooling, heating, and power system, as well as the environmental analysis of the power plant. Using Aspen software, an initial model of the trigeneration cycle power plant is designed and the layout and arrangement of the cycle are accomplished. The mass flow of waste consumed at the power plant is 8333 kg/h and power generation is 3 MW. Heat losses from boiler exhaust gases are inserted into a heat exchanger modeled by EES software to meet the heat requirement. The heat exchanger efficiency is 70%, and the outlet water temperature is calculated as 70°C. The exhaust gases from the heat exchanger have been fed into the water-ammonia absorption chiller to meet the cooling requirement. The cooling capacity of the first evaporator is 1111 kW and for the second evaporator, it is calculated to be 529 kW. The power plant energy efficiency is 35%, and when it is converted into a combined cooling, heating, and power (CCHP) system the total efficiency of the system increases by 70%. The economic feasibility of the project has been checked, and the payback period has been estimated to be about 2.5 years. This study shows that CCHP systems using incineration plants as prime movers can play an important role in providing energy requirements and sustainable development.