A Study of MILD Combustion Characteristics Using FGR in a 180 kWth Incinerator

Seonghwan Hwang; Taeyoung Chae; Woohyun Sim; Yongwoon Lee; Won Yang; Jae Wook Lee; Oh Chae Kwon; Minsoo Kim

doi:10.15231/jksc.2025.30.4.038

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2025 Vol.30, Issue 4 Preview Page Next Page

Research Article

A Study of MILD Combustion Characteristics Using FGR in a 180 kW_th Incinerator 180 kW_th 급 소각로에서 FGR을 이용한 MILD 연소 특성 연구

31 December 2025. pp. 38-48

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Abstract

As waste management practices and policies have evolved, the composition of municipal waste has shifted, raising its average heating value from 1,945 kcal/kg to 4,025 kcal/kg over the past 20 years. This increase has resulted in incineration conditions that exceed the design specifications of existing facilities, with a notable rise in the combustion rate due to higher fractions of volatile synthetic resins. Consequently, instead of achieving uniform combustion as initially designed, the process now completes much faster, creating localized high-temperature zones. These zones cause issues such as facility damage, clinker formation, elevated NOx emissions, and reduced operational efficiency. To address these challenges, this study applies the MILD (moderate and intense low oxygen dilution) combustion technique using FGR (flue gas recirculation) technology in a 180 kW_th stoker-type incinerator. Wall temperatures were measured with nine thermocouples, exhaust gas concentrations were analyzed with a non-dispersive infrared (ND-IR) gas analyzer. The experiments varied FGR ratios (0%, 50%, 100%) and FGR injection locations to identify optimal operating conditions. The results showed that increasing the FGR ratio significantly reduced the maximum temperature within the incinerator. The greatest temperature reduction, along with decreased CO and NO emissions, was observed when 100% FGR was injected into both the upper and lower high-temperature zones.

Keywords

Waste incinerator

MILD combustion

Flue gas recirculation

NOx reduction

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Information

Publisher :The Korean Society of Combustion
Publisher(Ko) :한국연소학회
Journal Title :Journal of the Korean Society of Combustion
Journal Title(Ko) :한국연소학회지
Volume : 30
No :4
Pages :38-48
Received Date : 2025-11-25
Revised Date : 2025-12-09
Accepted Date : 2025-12-09
DOI :https://doi.org/10.15231/jksc.2025.30.4.038

Journal of the Korean Society of Combustion ISSN:1226-0959(Print) 2466-2089(Online) 한국연소학회지

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