CFD simulation of MSW combustion and SNCR in a commercial incinerator

Journal Article · Mon Sep 15 04:00:00 EDT 2014 · Waste Management

DOI:https://doi.org/10.1016/J.WASMAN.2014.04.015· OSTI ID:22443590

Xia, Zihong; Li, Jian; Wu, Tingting ^[1]; Chen, Caixia ^[1]; Zhang, Xiaoke ^[2]

---

1. Key Laboratory of Coal Gasification and Energy Chemical Engineering of Ministry of Education, East China University of Science and Technology, Shanghai (China)
2. Shanghai Environment Group Company, 1881 Hongqiao Road, Shanghai 200336 (China)

Highlights: • Presented a CFD scheme for modeling MSW incinerator including SNCR process. • Performed a sensitivity analysis of SNCR operating conditions. • Non-uniform distributions of gas velocity, temperature and NO{sub x} in the incinerator. • The injection position of reagent was critical for a desirable performance of SNCR. • A NSR 1.5 was recommended as a compromise of NO{sub x} reduction rates and NH{sub 3} slip. - Abstract: A CFD scheme was presented for modeling municipal solid waste (MSW) combustion in a moving-grate incinerator, including the in-bed burning of solid wastes, the out-of-bed burnout of gaseous volatiles, and the selective non-catalytic reduction (SNCR) process between urea (CO(NH{sub 2}){sub 2}) and NO{sub x}. The in-bed calculations provided 2-D profiles of the gas–solid temperatures and the gas species concentrations along the bed length, which were then used as inlet conditions for the out-of-bed computations. The over-bed simulations provided the profiles of incident radiation heat flux on the top of bed. A 3-dimensional benchmark simulation was conducted with a 750 t/day commercial incinerator using the present coupling scheme incorporating with a reduced SNCR reduction mechanism. Numerical tests were performed to investigate the effects of operating parameters such as injection position, injection speed and the normalized stoichiometric ratio (NSR) on the SNCR performance. The simulation results showed that the distributions of gas velocity, temperature and NO{sub x} concentration were highly non-uniform, which made the injection position one of the most sensitive operating parameters influencing the SNCR performance of moving grate incinerators. The simulation results also showed that multi-layer injections were needed to meet the EU2000 standard, and a NSR 1.5 was suggested as a compromise of a satisfactory NO{sub x} reduction and reasonable NH{sub 3} slip rates. This work provided useful guides to the design and operation of SNCR process in moving-grate incinerators.

• OSTI ID: 22443590
• Journal Information: Waste Management, Journal Name: Waste Management Journal Issue: 9 Vol. 34; ISSN WAMAE2; ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
42 ENGINEERING
AMMONIA
BENCHMARKS
BURNOUT
CARBON MONOXIDE
COMBUSTION
COMPUTERIZED SIMULATION
CONCENTRATION RATIO
FLUID MECHANICS
HEAT FLUX
INCINERATORS
MUNICIPAL WASTES
NITROGEN OXIDES
REAGENTS
SENSITIVITY ANALYSIS
SOLID WASTES
STOICHIOMETRY
TEMPERATURE DISTRIBUTION
THREE-DIMENSIONAL CALCULATIONS
VOLATILITY