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

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 w ill 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.

KEYWORDS:

• CCHP
• waste incineration plant
• heat exchanger
• absorption chiller
• energy and exergy efficiency
• payback period

Nomenclature and abbreviations

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Additional information

Notes on contributors

Mahmood Chahartaghi

Mahmood Chahartaghi received his Ph.D. degree in Mechanical Engineering from Iran University of Science and Technology (IUST), Tehran, Iran, in the field of energy conversion. He works as an associate professor in the Faculty of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran. His research activities are mostly on thermodynamics, energy, refrigeration and air conditioning systems, combined cooling, heating and power (CCHP) systems, renewable energy sources, exergy analysis, modeling of energy systems and water treatment plants.

Naser Dahmardeh

Naser Dahmardeh received his M.Sc. degree in Shahrood University of Technology, Shahrood, Iran in the field of Energy Systems Engineering His research activities are about energy, economic and exergy analyses of CCHP systems as well as modeling and optimization of waste incineration power plants.

Seyed Majid Hashemian

Seyed Majid Hashemian is an emeritus assistant professor of mechanical engineering inFaculty of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran. He obtained the Ph.D. of Mechanical Engineering in the field of energy conversion from Shahid Bahonar University of Kerman, Iran. His research activities are mostly on thermodynamics, thermal power plants, energy, exergy and pinch analyses, modeling of energy systems, energy management as well as renewable energy sources.

Rahmat Malek

Rahmat Malek received his M.Sc. degree in Shahrood University of Technology, Shahrood, Iran in the field of Energy Systems Engineering. His research activities are about modeling of CCHP systems, energy, exergy and economic analyses of thermal systems, modeling and optimization of waste incineration power plants as well as process analysis of industrial systems.