The recovery of waste heat of flue gas from gas boilers

Xiling ZhaoDepartment of Building Science, School of Architecture, Tsinghua University, Buiding Energy Research Center, 402A, Haidian District, Beijing, 100084, PR ChinaCorrespondence[email protected]
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Lin FuDepartment of Building Science, School of Architecture, Tsinghua University, Buiding Energy Research Center, 402A, Haidian District, Beijing, 100084, PR China;Beijing Key Laboratory of Indoor Air Quality Evaluation and Control (Tsinghua University), Beijing, ChinaView further author information

Tao SunDepartment of Building Science, School of Architecture, Tsinghua University, Buiding Energy Research Center, 402A, Haidian District, Beijing, 100084, PR ChinaView further author information

Jing Yi WangDepartment of Building Science, School of Architecture, Tsinghua University, Buiding Energy Research Center, 402A, Haidian District, Beijing, 100084, PR ChinaView further author information

Xiao Yin WangDepartment of Building Science, School of Architecture, Tsinghua University, Buiding Energy Research Center, 402A, Haidian District, Beijing, 100084, PR ChinaView further author information

Abstract

There is a large amount of water vapor with substantial latent heat in the flue gas from natural gas boilers. The energy efficiency could be improved significantly by the recovery of the waste latent heat. This article analyzes the potential of waste heat recovery, proposes the problems of traditional district heating systems, and develops a new process flow, which could reduce the outlet temperature of the flue gas to about 20°C. An experiment of this process has been conducted, as well as the analysis of energy consumption and economic performance. The reduction rate of energy consumption is 10% to 15%, and the payback year is less than 3 years.