Flame Emission Research Articles

Flame temperature and emissivity distribution measurement of solid propellant based on clustering analysis of multispectral radiation images.

To measure the combustion parameters of a solid propellant, this Letter researches the fitting method for flame temperature and emissivity based on multispectral images and proposes the particle swarm optimization-K-means (PSO-K-means) clustering optimization algorithm of a flame multispectral image. Considering the difference in flame radiation characteristics in different regions, the flame multispectral image is clustered, and spectra in different regions are analyzed and selected in different fitting bands to inverse temperature and emissivity. On this basis, the method is applied to measure solid propellant combustion parameters with different formulations. The measurement shows that the flame temperature is between 1700 and 2100 K, and the emissivity is concentrated in 0.1-0.5. Compared with temperature measurements obtained from tungsten-rhenium thermocouples, the relative deviation of multispectral imaging thermometry is less than 5%. The distribution characteristics of solid propellant combustion parameters with different formulations were analyzed, which provided important data support for evaluating combustion conditions and optimizing solid propellant formulations.

Emissions and Flame Stability Assessment of Hydrogen Addition and Air Dilution in a Micro Gas Turbine Combustor Using 0D/1D Modeling by Chemical Reactor Network

Abstract Hydrogen emerges as a promising fuel for clean and sustain- able electricity production when utilized in micro gas turbines (mGTs). However, some challenges linked to hydrogen usage must be overcome as its high reactivity can lead to increased NOx emissions and flame instabilities. Literature suggests that combustion air humidification and/or exhaust gas recirculation (EGR) may be methods to reduce this reactivity. However, these measures are limited due to the small operating range of the mGT combustor. In this context, a 20 kWth mGT combustor is investigated un- der various inlet conditions to assess the effect of EGR towards increased flame stability and emission control when operating under hydrogen-enriched methane firing, using a Chemical Re- action Network (CRN) model. The CRN modeling is a fast and low computational complexity tool to model combustion perfor- mance and emissions by representing complex reactive flow fields through idealized reactor models, leading to reduced computa- tional costs. This study examines partial load conditions, fuel compositions, and the effect of combustion air dilution through EGR. The CRN model of the combustion process is designed based on combustion zones extracted from the main flow fields with similar thermo-chemical states from CFD, while emission predictions are experimentally validated for different operating points. Predicted NOx and CO emissions by the proposed CRN model show an acceptable agreement with the experimental data at high power loads. However, its accuracy diminishes for loads below 70% due to the variability in model tuning parameters across different loads, whereas the

Experimental studies on the influence of smoke acceleration effect feedback to the flame behavior in the U shaped shaft of a high-rise building

This paper presents an experimental investigation of the feedback effect with smoke acceleration on flame behaviors in the U shaped shaft of a high-rise building. Heat release rate of the fire, depths and widths of the U shaped shaft are changed. The flame height, vertical maximum temperature in the open shaft and the heat flux distribution on the façade are studied. Results show that the flame height is elongated by the smoke acceleration effect in the U shaped shaft and larger than that in the open space. Correlations for the flame height are established by taking into account the geometries of the U shaped shaft. The vertical maximum temperature in the U shaped shaft first decreases rapidly then keeps room temperature, which are compared with that under stack effect in the staircase. The exponential decay law between the vertical maximum temperature and height is modified. The total heat flux is mainly affected by the width and heat release rate. Radiation heat transfer fraction is larger than 80 % in the continuous and intermittent flame regions, of which the flame emissivity is about 0.53.

Numerical simulation of natural gas-ammonia combustion characteristics in a U-shaped radiant tube

NH3, recognized as a carbon-free fuel and a high-energy–density renewable hydrogen carrier, holds promise as a low-carbon alternative fuel. However, its direct combustion is often posed with challenges such as a limited ignition zone and high NOX emissions. To address this, the present paper proposes a strategy to blend more reactive hydrogen-containing fuels with ammonia to enhance combustion stability and concurrently reduce NOX emissions. This study developed numerical models for natural gas-ammonia combustion within a U-shaped radiant tube. The dynamic characteristics of combustion flame flow fields inside the radiation tube were investigated across various mixing ratios, analyzing the effects of nitrogen-containing fuel temperature on NOX generation and elucidating NOX generation patterns under different mixing ratios. The findings indicated that a 30 % NH3 blending ratio in the radiation tube yielded uniform wall temperature distribution along its length, minimal circumferential temperature variation, and an outlet NOX emission of only 20.3 ppm. Furthermore, Pearson correlation coefficient calculations revealed strong correlations between NH3 concentration (0.97), URT temperature (0.88), and NOX generation rate (0.88) within the U-type radiation tube combustion flame and NOX emission content.

Multispectral two-dimensional temperature field reconstruction using particle swarm optimization and the Broyden–Fletcher–Goldfarb–Shanno algorithm with multiple extreme value optimization

The flame temperature is a crucial parameter in combustion, indicating heat generation and transfer. However, determining the correct temperature becomes challenging when flame emissivity is unknown. This article presents a multispectral 2D temperature field reconstruction method using particle swarm optimization and the Broyden–Fletcher–Goldfarb–Shanno algorithm, combined with multivariate extreme-value optimization. This method establishes an objective function based on the correlation between the true temperature and spectral data. The objective function was minimized by adjusting the emissivity, enabling the reconstruction of 2D temperature and emissivity images without assuming an emissivity model. Calibration with a multispectral camera yielded the spectral response coefficients, and three-time spline interpolation was used to verify the calibration data. The reconstructed 2D temperature field showed a mean absolute error (MAE) of 4.61 and structural similarity (SSIM) of 0.995. The reconstructed emissivity image had an MAE range of 0.04 to 0.053 and an SSIM range of 0.897 to 0.915. The system, tested on a butane flame, showed a temperature range of 1001 K to 1356 K, with an average temperature of 1194 K and emissivity values ranging from 0.3166 to 0.8621. The results align with the expected combustion process and radiation characteristics distribution of the butane flame.

Chemical elements migration in underground waters of mining territory

Relevance. The need to study the forms of migration of chemical elements in the groundwater of flooded copper pyrite mines in order to correctly understand and predict their transfer and distribution in hydrogeochemical fields. Ground and surface waters are a complex mixture of substances in which, depending on pH, Eh and t °С, phase transitions are formed with subsequent dissolution or precipitation of minerals. To solve these problems, numerical hydrogeomigration modeling is used, including physicochemical, which allows drawing conclusions about the scale of pollution and the localization of such areas for subsequent development of measures to improve the state of the hydrosphere. Aim. To determine the forms of metal migration in groundwater and to calculate water saturation indices in relation to minerals. Objects. Groundwater in the territory of the closed Levikha copper pyrite mine. Methods. Laboratory studies of groundwater were carried out using flame emission spectrometry, flame atomic absorption, photometric method with Nessler's reagent, titrimetric, mercumetric and potentiometric methods; mass spectrometry with ionization in inductively coupled plasma and gravimetric method. Physical and chemical modeling using the software product Visual MINTEQ 3.1. Results. According to the results of processing chemical analyzes and physical and chemical modeling, all tested wells are divided into groups: 1) wells no. 1, 2, 3 and 6, located within the former mining allotment (near the Levikha XIV mine, a man-made reservoir, the Levikha II mine and a neutralization station); 2) represented by water in wells no. 4 near the shaft of the mine Tsentralnaya and no. 5 near the dump Yuzhny; 3) well no. 7, located near the mouth of the Levikha river. Saturation indices and forms of migration of components in the aquatic environment make it possible to identify the scale of pollution and the localization of such areas. Thus, with the current pumping system, there is no large-scale pollution of groundwater at the Levikha mine. It is localized in the area of the Tsentralny mine shaft (well no. 4) and the Yuzhny dump (well no. 5).

Measurement of unburned methane emissions in laboratory flames using mid-infrared hyperspectral imaging

In this study, we present a novel method for measuring unburned methane (CH4) emissions in laboratory flames using mid-infrared hyperspectral imaging. Given the environmental significance of methane’s global warming potential, accurately quantifying emissions from combustion processes is critical. Our approach integrates an extended-area blackbody as the infrared source and a bandpass interference filter to mitigate issues of noise, low signal levels and detector saturation. This setup enabled high-resolution spectral analysis, capturing detailed concentration and temperature maps of methane around the flame. We tracked the dynamics of methane pockets escaping the flame using the hyperspectral imaging system in high-speed camera mode, providing insights into the behavior of unburned gases, such as the velocity of methane pockets. The study demonstrates the feasibility of this technique for assessing combustion efficiency by quantifying the flow of unburned methane through a control surface. Our findings suggest that mid-infrared hyperspectral imaging is a robust tool for remote sensing of methane emissions, offering significant advancements in the accurate measurement and analysis of combustion processes, and providing a benchmarking platform for measurement approaches intended for field applications.

Flame stabilization and emission reduction: a comprehensive study on the influence of swirl velocity in hydrogen fuel-based burner design

PurposeThis study aims to numerically analyse a full-scale burner across a wide range of operating pressure conditions and determine the effect of swirl velocity on flame stabilization, flame holding and combustion performance.Design/methodology/approachThis study uses a numerical analysis approach to investigate a three-dimensional full-scale burner. Modified governing equations are used to determine the effect of swirl velocity on flame stabilization and flame holding. The GR-Mech 3.0 chemical reaction mechanism is used to predict the combustion process. To validate the model, a grid independence study is performed.FindingsThe study reveals that swirl velocity enhances flame stability, resulting in better combustion rates. As the swirl velocity increases, higher flame temperatures are observed due to high convective heat recirculation. The heat transfer coefficient and high radiative extinction coefficient are found to vary based on fuel swirl velocity. The mass fraction of CH4 and CO emphasizes the role of swirl velocity on flame structure. Increasing velocity potentially improves combustion by delaying the process, leading to better combustion and lower emissions.Originality/valueThe findings of this study contribute to the understanding of swirl-stabilized combustion and can guide the development of advanced combustion technologies, making it a valuable addition to the existing combustion field.

Portable X‐ray fluorescence spectrometry accurately measures metal concentrations in aqueous Mehlich III soil extraction solutions

AbstractAccurate measurement of metal concentrations in soil and water is vital for healthy crop production and decision making for environmental surveys. While there are a multitude of laboratory‐based soil analysis methods, such as inductively coupled plasma‐optical emission spectroscopy (ICP‐OES), flame emission spectrometry, and atomic absorption spectroscopy, most are time and resource intensive. Additionally, there is a lack of information for rapid analysis of elements for aqueous soil extractions. The goal of this research is to establish elemental correlations between portable X‐ray fluorescence (pXRF) measurements of Mehlich III soil extractions and traditional elemental measurements via ICP‐OES. We hypothesize that certain metals can be accurately measured in aqueous soil extraction solutions by pXRF to the same degree as they are measured by ICP‐OES. To test this hypothesis, Mehlich III and 2% nitric acid solutions with known elemental concentrations were analyzed via ICP‐OES and pXRF. Soil samples extracted using Mehlich III were compared between ICP‐OES and pXRF to verify correlations. High correlations were found for As, Ca, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, V, and Zn in both the Mehlich III and 2% nitric acid solutions at concentrations between 5 and 85 mg L−1. P, S, and Si did not show high correlations at concentrations <100 mg L−1. These results indicate that between 5 and 85 mg L−1, pXRF analysis of aqueous solutions and soil extractions is a reliable technique; however, at low concentrations (i.e., <5 mg L−1 for metals and <100 mg L−1 for P and S), pXRF is not well suited.

Statistical analysis of fuel combustion and emissions considering the adverse effects of investment economic environment: Exploring alternatives amid oil prices Swings, digital economy, and local market inflation

The depletion of natural gas reserves, combined with rising oil prices, local market inflation, and concerns about pollution, has accelerated the search for alternative energy sources. As a result, research on turbines and internal combustion engines for electricity generation is increasingly focusing on using vaporized ethanol as a fuel substitute. However, the high cost of analyzing the chemical composition of these fuels often leads to an oversight of their impact on combustion characteristics, such as flame behavior, emission profiles, and temperature distribution.This study employs a statistical approach to assess the combustion and emission characteristics of biofuels, aiming to find suitable alternatives to petroleum-based fuels. By integrating considerations of oil price fluctuations and the digital economy's impact, the research proposes a cost-effective method for evaluating the chemical makeup of vaporized fuels and their effects on post-combustion pollution.Experimental data reveal that alternative fuels can offer stable ignition performance and lower pollution levels, contingent on their specific properties. Fuels with high aromatic content and viscosity tend to produce significant CO emissions, while reducing these characteristics may increase CO2 production. The study also highlights the challenge of simultaneously reducing both CO and NOx emissions. Additionally, the findings show that petroleum gasoline, due to its lower volatility, has favorable fire safety properties and generates fewer pollutants.In the context of economic pressures from rising oil prices and inflation, this research underscores the importance of exploring biofuels as viable, sustainable alternatives for the future energy landscape.

A New Air-Assisted Flare Tip Design for Managing Gas Flare Emissions (CFD Analysis)

Recently, flares have been considered as a major source of air pollution from the petroleum refining industry. The United Nations has instigated an international effort related to the management of flare emissions to reduce the global warming impact related to flaring. Eliminating or removing the need for gas flares is difficult because these devices are generally used as safety devices to allow the combustion of flammable gases in a controlled fashion which supports safe operation. However, reducing flaring is generally possible using well-designed, efficiently operated flare equipment. In general, flare performance can be enhanced following the API-521 methodology and using assist-media including air and steam to achieve smokeless operation. This present work will discuss flare emissions in the petroleum refining industry and a method to manage flare emissions. Moreover, this work will discuss flare combustion efficiency (CE) and destruction and removal efficiency (DRE) in terms of efficient flare operation. This work uses actual operating flare data, published previously, which will be used in this work together with the CFD Code C3d. This code, developed at the USDOE Sandia National Laboratory, is based on a standard LES methodology to conduct transient flare analysis and is used to simulate flare operation to estimate flame shape and emissions produced. In this work, a new air-assisted flare tip design which uses the Coanda effect to improve flare operation was analyzed. This new flare design reduces the emission rate and demonstrates the design’s effectiveness. The analysis considers a flare 39″ high and 6″ diameter in the center of a 4m x 4m x 4m domain. Boundary conditions assume no cross wind and an ambient temperature of 300 K. The initial condition is a hydrostatic pressure profile across the computational domain. In the air-assist simulation, stoichiometric ratio will be a variable, and therefore, more than one case was considered.

The study of solid flame model of diffusion jet flame for the ammonia and propane mixed gas under the inclined ceiling

In order to solve the environmental pollution and energy dilemma, the ammonia has been considered as a new fuel and a carbon-free hydrogen carrier, which can be blended into the traditional hydrocarbon fuels. In this study, the evolution of flame emissivity, view factor and radiative heat flux have been investigated under different mass flow rates of ammonia and propane, and inclined angle of ceiling. A radiation prediction model of ammonia-propane mixed gas jet flame under inclined ceiling with different inclined angles has been developed. This prediction model can accurately describe the flame morphology and simplify the calculations, and consider the influence of mixing ratio on combustion reaction. The experimental results indicated that the flame emissivity, view factor, and radiative heat flux decrease with the increase of ammonia concentration. The prediction error of the traditional model will be enlarged with the increase in the inclined angle of ceiling. The modified model added the undersurface of ceiling jet flame, which reduces the prediction error from 25 % to 14 %. These prediction models are helpful in predicting the thermal radiation of jet flame under inclined ceiling.

Influence of AM Generated Burner Surface Roughness on NOx Emissions and Operability of Hydrogen-Rich Fuels

ABSTRACT The additive manufacturing (AM) technique enables the fabrication of advanced burner components to enhance the hydrogen capability of the existing gas turbines (GTs) and reduce the carbon footprints of the power generation sector. This technique produces rough surfaces that may require post-processing to maintain the desired functionality of a burner, particularly for hydrogen fuel with unique thermo-physical properties. This study, therefore, compared the stability of three swirlers of variable surface roughness manufactured using AM and traditional machining methods, with one of the AM swirler post-processed by grit-blasting. The comparison included a conventional benchmark (100% CH4), low carbon (23%volCH4/77%volH2) and zero carbon (100% H2) fuels across a range of equivalence ratios. Additionally, the study quantified the flame topology and emissions performance of the fuel blends for each swirler using high-speed OH* chemiluminescence and exhaust gas emissions measurements, respectively. The experimental investigation concluded that the AM-generated surface roughness within the considered range does not detrimentally impact NOX emissions and the stability of the fuel mix. However, the flame location was observed to be influenced by surface roughness and shifted more toward the vertical centerline of the burner with increased roughness. From the practical perspective, the results showed that post-manufacturing surface finishing offers negligible performance advantages, indicating potential cost reductions. It is recommended that further studies should investigate the influence of increased surface roughness on burner performance, as well as numerical modeling techniques which could provide an insight into when AM surfaces are likely to be more influential.

The influence of radiation modeling on flame characteristics and emissions prediction in microcombustors with Ammonia/Hydrogen blends

This study advances numerical methodologies for designing microcombustor-based thermophotovoltaic systems by incorporating comprehensive analyses of radiation models and absorption coefficients. It examines the impact of non-premixed hydrogen-ammonia-air fuel blends on the micro combustion process using three-dimensional CFD simulations on a Y-shaped microcombustor under atmospheric conditions.Key to this research is modeling radiative heat transfer from multiple species, including ammonia (NH3), nitric oxide (NO), and water vapor, ensuring accurate predictions and optimization of thermal behavior and efficiency. Three modeling approaches were compared: a multispecies Planck-mean approximation radiation model (PMAC), a narrowband model for water vapor, and a scenario excluding radiation effects.The PMAC model, incorporating the absorption coefficients of ammonia and its products, consistently produced lower errors in flame length compared to the NB method across all equivalence ratios, with errors ranging from 0 % to 7 % for PMAC and 10 % to 30 % for NB, with the lowest error observed at Φ = 1.0. Additionally, the prediction of laminar burning velocity (LBV) differed by approximately 4 % between the two models.Considering different fuel blends, two scenarios were compared: constant input thermal power and constant fuel flow rate. Efficiency in the constant input thermal power scenario maintained higher radiation efficiency, in the range of 32–38%. Additionally, radiation efficiency initially increased with increasing H2 content but subsequently decreased for high H2 values due to effects on flame area, flame position, and temperature.

Quantification of Ions in Human Urine-A Review for Clinical Laboratories.

Urine is an organic fluid produced by the kidney, and its analysis is one of the most requested laboratory tests by clinicians. The ionic composition of urine has been shown to be a good health indicator: it is useful for the diagnosis of several diseases, as well as monitoring therapeutics. This review considers laboratorial techniques that have been used throughout time for the quantification of ions in urine, and also considers some methodologies that can potentially be used in clinical laboratories for this kind of analysis. Those methods include gravimetry, titration, flame emission spectrophotometry (flame photometry), fluorimetry, potentiometry (ion selective electrodes), ion chromatography, electrophoresis, kinetic colorimetric tests, enzymatic colorimetric tests, flow cytometry, atomic absorption, plasma atomic emission spectrometry, and paper-based devices. Sodium, potassium, chloride, calcium, and magnesium are among the most important physiological ions, and their determination is frequently requested in hospitals. There have been many advances regarding the analysis of these ions in 24 h urine. However, there is still some way to go concerning the importance of intracellular ions in this type of sample as well as the use of occasional urine for monitoring these parameters.

A Reactor-Network Framework to Model Performance and Emissions of a Longitudinally-Staged Combustion System for Carbon-Free Fuels

Abstract Hydrogen and ammonia are considered crucial carbon-free energy carriers optimally suited for seasonal chemical storage and energy system balance. In this context, longitudinally-staged combustion systems (LSC) represent an attractive technology for achieving low emissions while conserving high load and fuel flexibility at high efficiency. While these two-stage combustion systems have been successfully implemented for natural gas and hydrogen firing of gas turbines, optimal operation with ammonia-based fuel mixtures not yet established. Recent works have shown that ammonia can be combusted with low emissions in gas turbines by employing a Rich-Quench-Lean operational concept where a slightly rich fuel-air mixture is burnt in the first-stage followed by dilution air addition, which completely oxidizes the remaining unburnt fuel. However, an optimal operational strategy to efficiently combust all three fuels within the same system is yet to be established. In this work, we exploit a reactors-network framework to efficiently investigate the emissions performance of a LSC system fired with natural gas, hydrogen and ammonia. Firstly, the framework is validated with experimental and computational emission results in the literature. Secondly, the optimal operational strategy (in terms of fuel- and air-split between the stages) for clean and efficient ammonia-firing operation is found. Thirdly, the consequences of such ammonia-optimized operational strategy on flame stabilization and emissions with natural gas- and hydrogen are considered. Finally, the air and fuel distribution for optimal performance and minimal emissions for all three fuels is found for the LSC system.

Effect of air distribution mode on jet flame and emission characteristics of high temperature gas-solid mixed fuel

The characteristics of the flame can not only intuitively reflect the flow, mixing and reaction processes of fuel and oxidant, but also provide detailed information on combustion efficiency and stability. The present study aims to delve into the jet flame characteristics and emission properties of high-temperature gas-solid mixed fuel. A comprehensive series of experiments were conducted on a custom-designed test platform. During the experiments, variations in both the position (h3 = 200, 600, 1000 mm) and velocity (v3 = 67, 138, 223 m/s) of the tertiary air were introduced. The study focused on analyzing the flame lift-off distance, the correlation coefficient of the flame root, the normalized root mean square temperature distribution within the flame body area, and the NOx emission characteristics across various air distribution scenarios. The experimental findings reveal that alterations in the position of tertiary air exert a greater influence on the flame lift-off distance than variations in its velocity. Furthermore, temporal fluctuations in the correlation coefficient of the flame root and the normalized root mean square temperature distribution within the flame body region serve as effective indicators of flame stability. Notably, an increase in both the tertiary air position and velocity leads to a notable reduction in NOx emissions. Additionally, through a quantitative analysis of flame stability, temperature distribution uniformity, and NOx emission characteristics, this study establishes a correlation between flame characteristics and pollutant emission profiles. This correlation offers a more comprehensive understanding of the combustion process involved in high-temperature gas-solid mixed fuel.

Effect of swirl number on structural and emission characteristics of moderate size burner flames

An experimental investigation was conducted on the flame characteristics, thermal properties, and emissions of industrial-scale (40 kW) diesel flames. This study uniquely measured structural (flame length, diameter, volume), thermal (temperature, heat flux), and emission characteristics (COX, NOX, Unburnt HC) across various equivalence ratios (0.2–0.6) and swirling conditions (Swirl number varying from 0.73 to 1.04). Results indicated that higher swirl numbers generally led to more stable and compact flames, though structural properties were less affected during lean combustion. Notably, flame temperature varied significantly, up to 350 K, resulting in substantial difference in specified emission products. The emission reductions were achieved, particularly with a geometric swirl number of 1.04, which balanced flame performance and emission both, achieving reductions in CO (9–97 %), HC (18–96 %), NO (8–16 %), and Smoke (0.3–82 %). These findings underscore the critical impact of swirl angle on combustion efficiency and emissions, highlighting the need for meticulous optimization to mitigate harmful emissions effectively. This study provides new insights into optimizing combustion parameters for enhanced environmental sustainability in industrial processes.

Investigation effects of different calorific values and operating conditions on biogas flame: a CFD study

ABSTRACT This study investigates different biogas fuels’ and operating conditions’ effects on flame temperatures and emissions (CO, CO2, NOx, and soot). Different calorific values (15.580, 17.880, 20.430, 23.080, and 26.230 MJ/kg) were obtained by changing methane content. Furthermore, various gas pressure (0.5, 1, 2, and 3 atm), excess air coefficient (1.4, 1.8, 2.5, and 4), and oxygen values (21, 23, 25, and 27%) were simulated for 8.6 kW thermal capacity furnace. Increasing the calorific value of biogas fuels, CO, NOx, and soot emissions and flame length tend to increase, while CO2 decreases. Increasing gas pressure, flame temperature, and CO2, CO, and NOx decrease, while soot emissions tend to increase. As a result of the decrease in the air excess coefficient from 4.0 to 1.4, there is a increase in the flame temperature, flame length, and soot, CO, CO2, and NOx emissions. On the other hand, oxygen content from 21% to 27% oppositely affected these parameters, excluding flame length.

In-situ measurement of alkali metal concentrations and temperatures during the incineration of municipal solid waste and sludge

The release of alkali metals in municipal solid waste (MSW) incineration caused corrosion of thermal equipment and slagging in incinerator. By using a spectrometer and multispectral camera, the concentrations of Na and K, flame temperatures and emissivities in an industrial incinerator with different proportions of food waste, sludge, waste paper and waste fabric were measured in this study. The flame temperatures on the left wall decreased from 1479.5 K to 1366.2 K as the height increased from 13.4 m to 16.9 m. Flame temperatures near the left side of the incinerator were 8.9 % higher than those near the right side, which were caused by the ununiform distribution of MSW. The concentrations of Na and K increased by 67.16 % and 86.9 % with the primary air flow increased by 3969.35 t/h. The average concentrations of Na and K at 16.9 m of the left wall decreased by 25.87 % and 37.53 % with the decreasing of food waste and increasing of sludge. The Na and K contents in fixed carbon were greater than those in volatile matter and ash in fuels. Compared with waste paper and waste fabric, the blending of sludge with food waste was more effective on reducing the release of Na and K. When the proportion of food waste: sludge was set as 8:2, the lowest releases of Na 20.75 ppm and K 5.30 ppm existed in the incineration of food waste and sludge. The concentrations of Na and K decreased by 17.3 % and 46.9 % with the increasing of waste paper, the waste paper was a better alternative to sludge when mixed with MSW.