Numerical simulation analysis on the characteristics of municipal domestic waste with high calorific value and sludge co-combustion

Abstract

The combustion characteristics of a high calorific value domestic waste blend with municipal sludge of 350 t/d, 750 t/d, and 900 t/d in three kinds of mainstream mechanical waste incinerators in Guangdong were studied by numerical simulation method, and the model was verified with the operating data. Based on the “3 T” principle of incinerator, the combustion characteristics of mixed fuel with high calorific value municipal solid waste and sludge in different incinerators were analyzed. The results showed that when the maximum blending ratios of sludge in the 350 t/d, 750 t/d, and 900 t/d waste incinerators were 13%, 17%, and 10%, respectively, and the residence times of flue gas in the temperature region above 1123 K were 4.18 s, 3.68 s, and 6.36 s, respectively. The 750 t/d waste incinerator adopts a spiral secondary air injection mode, which is beneficial to the realization of “3 T” principle. The secondary air of the 350 t/d waste incinerator adopts the hedge injection mode, the first flue velocity is larger, and the flue gas residence time is shorter. 900 t/d waste incinerator combined with spiral and hedge injection, the temperature at the exit of one flue decreased by 61.12 K and 132.62 K compared to 0% working condition for 10% and 17% sludge blending, respectively, and the oxygen content increased from 2.97% to 3.91% and 5.63%. The appropriate primary and secondary air ratio and effective secondary air configuration can adjust the incinerator to be in the best operating condition.

KEYWORDS:

• High calorific value waste
• Sludge mixing combustion
• Numerical simulation
• Co-combustion
• 3T principle

Acknowledgments

This research work has been financially supported by Guangzhou Science Research Program (Key Project 201804020082), State Administration for Market Regulation Science and Technology Project (No. 2017QK152).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website.

Additional information

Funding

This work was supported by Guangzhou Science and Technology Program key projects (201804020082), Guangdong Key Laboratory of Efficient and Clean Energy Utilization, South China University of technology (2013A061401005).

Notes on contributors

Tao Lin

Tao Lin obtained Bachelor degree in Thermal Energy and Power Engineering from Guangdong University of Technology in 2016. He is currently a doctoral candidate in South China University of Technology. His research interests are efficient and clean utilize of energy.

Yan-fen Liao

Yanfen Liao obtained Ph.D. degree in Engineering Thermophysics from Zhejiang University in 2003. She is currently professor and doctoral supervisor at South China University of Technology. Her research interests are efficient and clean utilize of energy.

Xu-Cong Yang

Xucong Yang obtained Bachelor degree in Energy and Environmental System Engineering from Dalian University of Technology in 2019. He is currently a Master degree candidate in south China University of Technology. His research interests are efficient and clean utilize of energy.

Xiao-qian Ma

Xiaoqian Ma obtained Ph.D. degree from Huazhong University of Technology in 1995. He is currently professor and doctoral supervisor at South China University of Technology. His research interests are efficient and clean utilize of energy.