CO Emission Concentration Research Articles

Numerical Simulation Study of Combustion under Different Excess Air Factors in a Flow Pulverized Coal Burner

The basic national condition that is dominated by coal will not alter in the foreseeable future. Coal-fired boiler is the main equipment for coal utilization, and cyclone burner is a practical type of burner. There is a cyclone formation, a primary air duct inside the center air duct, and a secondary air duct. Introducing a small stream of pulverized coal gas or oil mist stream or gas directly into the reflux zone in the center duct ignites first a stable combustion and a small fluctuation of ignition pressure. In this paper, the variation of furnace temperature for cyclone pulverized coal burner corresponding to different excess air factors and the composition of gases such as O2, CO, CO2, and NOX produced by combustion were investigated using fluent software. A single cyclone pulverized coal burner from an actual coal-fired boiler is used, and a combustion zone applicable to the study of a single pulverized coal burner is established to study the actual operation of a single pulverized coal burner at different excess air coefficients. The findings indicate that the ignition position of pulverized coal combustion advances with decreasing α (Excess Air Factors); however, the length of the produced high-temperature flame gets shorter. As the value of α decreases, the burnout in the furnace decreases and the CO emission concentration increases, with a maximum CO mole fraction of 0.38% at α = 1.2 and a maximum CO mole fraction of 3.13% at the axial position when α decreases to 0.8. The furnace’s concentration of NOX, the NOX emission level decreases significantly with decreasing α. The NOX mole mass increases gradually with increasing α, and in the bottom portion of the primary combustion zone, more NOX is produced. The concentration of NOX in the chamber changes significantly after α exceeds 1.0, and the NOX at the outlet surges from 417.25 ppm to 801.07 ppm, which is attributed to the increase in the average temperature of the chamber, which promotes the generation of thermophilic NOX. The distribution pattern of O2 mole fraction along the furnace height cross-section at different excess air factors is basically the same, with a maximum at the burner inlet and a gradual decrease in the O2 content as it enters the combustion chamber to react with the pulverized coal in a combustion reaction. The value of α = 0.8 when the air supply is obviously insufficient, the fuel cannot be fully combusted, and only a small amount of CO2 is produced.

Assessing the impact of sargassum algae biodiesel blends on energy conversion in a modified single-cylinder diesel engine with a silica-incorporated diamond-like coated piston

ABSTRACT As coal and oil reserves deplete, the world is shifting to alternative fuels and renewable energy. Researchers are exploring a cleaner alternative to fossil fuels for powering automobiles. In this investigation, biodiesel was synthesized from brown marine algae (Sargassum algae) using transesterification process. Silica-incorporated diamond-like coating (DLC) was done on the engine piston by using the chemical vapor deposition (CVD) process with flow rate of 7sccm of C2H2. Three different coating thicknesses, such as 50,100, and 150 µm, were employed on the CI engine piston. Mechanical properties such as hardness, wear, and microstructure analysis were investigated. Analysis of mechanical characteristics reveals that pistons with a 100 μm coating have enhanced characteristics compared to those with other pistons. Using a 100 μm silicon coated piston on a single-cylinder Kirloskar engine, four blends (B10, B20, B30, and B40) were compared to neat diesel. At maximum engine load conditions, the B40 blends produced 42 ppm of HC whereas neat diesel with 19 ppm which is 57% higher than diesel and CO emission concentration increased by 4.9% than diesel. Similarly, brake-specific fuel consumption was observed at maximum load conditions for diesel with 0.18 kg/kWh and 0.20 kg/kWh for B10D90 which is 9.54% higher than diesel. As a result, it is critical to recognize the importance of sargassum’s potential for producing sustainable energy toward green globalization.

Effect of oxidation on the combustion flame characteristics of Jatropha biodiesel

This study investigated the effect of oxidation on the pyrolysis and combustion flame performance of Jatropha biodiesel. To analyze the escape characteristics of multi-component gas products during the pyrolysis and high-temperature oxidation processes of fresh and oxidized Jatropha biodiesel, the TG-FTIR-MS combined system was employed. In addition, various analytical equipment such as an OH-PLIF system, a flue gas analyzer, a spectral analyzer, and a transmission electron microscope were employed to examine the laminar premixed combustion flame and pollutant emissions of Jatropha biodiesel before and after oxidation. The results demonstrate that oxidation exhibits a nonlinear effect on the thermal decomposition of Jatropha biodiesel. Notably, the reaction activation energy exhibits an initial increase and followed by a decrease. Moreover, an increased oxidation degree led to a reduction in the activation energy of the high-temperature oxidation reaction of Jatropha biodiesel, without considerably affecting the total weight loss temperature. Furthermore, the peak temperatures of DTG and DSC exhibited a minor decrease. The production of C2, CH, and OH free radicals in the combustion flame of oxidized Jatropha biodiesel increased, along with an elevation in the spectral intensity of carbon smoke. With an increase in the degree of oxidation, the CO emission concentration from the combustion of Jatropha biodiesel decreased gradually from 75 mg/m3 to 36 mg/m3 after 6 h of oxidation. Additionally, NOx emissions gradually increased from 131 mg/m3 to 186 mg/m3 after 6 h of oxidation, and the particle size of carbon smoke exhibited a reduction of 28%.

Estimasi Emisi Kendaraan Ringan pada Ruas Jalan Perintis Kemerdekaan Kota Makassar

Population growth is increasingly demanding economic growth accompanied by the need for transportation as facilities of movement person and goods. The increase of transport it is not balanced with the right policies will cause various problems appertain the increasing number of motorized vehicles that has an impact on the environment, namely increasing air pollution. Exhaust emissions from motorized vehicles originating from fossil fuels make impact the environment. Various studies on transportation models have been developed by many researchers, various transportation models can also estimate emissions from motorized vehicles included MOVES and IVEM. The aim of this study is to analyze whether there are differences between the results of the emission estimation model in the MOVES and IVEM programs. The method used is using a driving cycle, where the vehicle is tracking on the highway using GPS second per second. Tracking is carried out on the Perintis Kemerdekaan road with a starting point of KM 7.75 to the end point of KM 13.12 as well as for the opposite direction. Tracking done at peak hours of 7-10 am, 11-14 noon, and 11-14 afternoon. The results showed that the concentration of Nox emissions was higher in the MOVES model data analysis than the IVEM model, as the CO emission concentration in the morning and evening was higher in the MOVES model and the CO emission concentration during the day was higher in the IVEM model. Statistically with the t test, the result is 0.13 where the result of the CO concentration for the MOVES and IVEM models are the same and for the t test the NOx concentration is 0.008 that the results of the analysis of the IVEM and MOVES models for NOx are not the same.

Study on the real-world emission characteristics of gaseous and particulate pollutants from an inland ship using a portable emission measurement system.

The emissions of pollutants from inland ships endanger the urban environment and human health, deserving quantitative study to make reduction measurements to achieve clean emissions. In this study, the real-world gaseous emissions (CO, THC, SO2, NOx) and particulate emissions including particle mass (PM) and particle number (PN) as well as the particle size distribution and particle compositions from an inland ship were investigated using a portable emission measurement system (PEMS) method. The results showed that the emission concentrations of CO, THC, PM and PN at departure and idling conditions were significantly higher than those at other conditions, while the emission concentrations of NOx and SO2 at cruising condition were the highest. The particle size distribution always presented a bimodal distribution ranged at 40nm and 200nm respectively at different conditions and engine loads. The proportion of nucleation mode particles was the highest at departure condition, and a larger engine load resulted in a declined proportion of nucleation mode particles. The anions of the emitted particles mainly included nitrite ion (NO2-), nitrate ion (NO3-), sulfate ion (SO42-), and cations mainly included ammonium ion (NH4+), sodium ion (Na+) and potassium ion (K+). The main components of organic carbon (OC) in soot were OC1 and OC2, accounting for more than 80%, while the main component of elemental carbon (EC) was EC2, accounting for 83.9%. The emission factors based on fuel consumption of CO and THC were significantly higher at idling conditions than other conditions, and the emission factor of NOx was higher at cruising conditions, while the emission factors of PM and PN were higher at departure and idling conditions than other conditions.

Industrial Experiment on NO x Reduction by Urea Solution Injection in the Fuel-Rich Zone of a 330 MW Tangentially Pulverized Coal-Fired Boiler.

The effects of various factors on NOx reduction by urea solution injection in the fuel-rich zone (UIFR) under a reducing atmosphere at high temperature were experimentally investigated in a 330 MW tangentially pulverized coal-fired boiler. The experimental results indicated that the NOx emission of the boiler could be effectively reduced by using the UIFR method, and the NOx reduction efficiency was mostly affected by the operating load of the boiler, the air distribution condition, and the boiler operating oxygen content (BOOC). The higher the load was, the larger the optimal normalized stoichiometric ratio (NSR) and the lower the NOx reduction efficiency became. As compared with the condition of conventional air distribution mode, the reducing atmosphere in the combustion zone could be enhanced under the condition of limiting air distribution (LAD) mode, which thus increased the NOx reduction efficiency of UIFR and reduced the optimal NSR value. A low BOOC could further increase the NOx reduction efficiency of UIFR. When the BOOC was, respectively, reduced to 1.71 and 1.85 vol % under 210 and 240 MW loads, the corresponding NOx reduction efficiencies of UIFR reached 45.3 and 41.3% in the LAD mode, respectively. However, the low BOOC increased the CO emission concentration, which could be avoided by the combined use of UIFR and high-velocity over-fire air. These experimental results can provide guidance for the ultra-low NOx emission of coal-fired boilers.

Assessment of Kitchen Air Pollution: Health Implications for the Residents of Ilorin South, Nigeria.

Indoor air quality is essential, so its quality cannot be compromised. Hence, this research assessed indoor gaseous air pollutant concentrations from sources in thirty-three residential kitchens within the 4-zone of Ilorin-South Local Government, Kwara, Nigeria. The work focused on SO2, NO2, and CO emission concentration quantification, determination of the air quality index (AQI), estimation of health assessment risk, and deduced their health implications on the residents. The concentrations of NO2 and SO2 were determined by the Saltzman method using a Gilair-3 air sampler, while the concentration of CO was determined using an MSA Altair-5x multigas detector. Three types of eleven kitchen environments each (kitchens where liquefied petroleum gas (LPG), charcoal, and firewood were used as fuel sources) were considered. The concentrations of NO2, SO2, and CO were higher in kitchens that used charcoal and firewood. The major health risks were deduced in percentages from the questionnaire administered, where headaches had the highest percentage (20.7). The model indicated that the concentrations of the pollutants in the evening, irrespective of the sampling points, were higher than those in the morning. Firewood contributed significantly more than charcoal and LPG (p < 0.05). The results of the health assessment risk showed that the risk estimated for normal exposure to the pollutants in all the households studied revealed a hazard quotient of <1.0 except for SO2 from firewood for infants and children = 1.09. The AQI results showed the worst health conditions for households that used firewood (0.103–4.760 ppm NO2; 0.327–0.647 ppm SO2; and 12.30–57.83 ppm CO). The study concluded that the use of LPG should be preferred as a source of fuel for cooking.

Tangential Flue Gas Recirculation (TFGR) technique for enhancement of radiation characteristics and reduction of NOx emission in natural gas burners

Experiments were carried out to find out the effect of different TFGR ratios on flame characteristics, pollutant emission, temperature, luminosity, IR radiation and total radiation of natural gas flames. A spiral duct connected tangentially to the furnace inlet linked the furnace to the chimney. A centrifugal fan was installed on the spiral duct to suck the combustion products and a spiral duct back-draft round damper was installed to adjust the FGR volume flow rate. The optical properties of the flame were studied for visible and IR wavelengths by a TES-1332 A digital luminance meter, a BOMEM FTIR and IR flame photography. Also, the total radiation of flame was determined by an SBG01 heat flux sensor. Furthermore, an S type thermocouple was used to measure the flame temperature. The results indicate that TFGR changes the nonluminous natural gas flame to a luminous flame by the dissociation of the recirculated CO2 to CO. TFGR enhances the tangential momentum of flame and generates a voluminous flame, increases the heat transfer area of flame and eliminates the hot-spot region in the core of flame, which decrease the axial flame temperature and thermal corrosion. Furthermore, the concentration and residence time of CO2 and H2O, as the most important radiative species of natural gas flames, increase in the flame reaction zone, which results in the enhancement of the IR emissivity and the radiation heat transfer of natural gas flame. Finally, although the TFGR increases the concentration of CO emission to a level lower than the standard level, it causes natural gas burners to emit significantly less dangerous NOx.

Incineration experiment of medical waste of novel coronavirus pneumonia (COVID-19) in a mobile animal carcass incinerator

Incineration experiment of medical waste was carried out in a mobile animal carcass incinerator. Simulated medical waste (69% cotton, 1.5% wood product, 4.5% mask and 25% moisture) was used as raw material. The temperature trend of first and second combustion chamber, the operating conditions and the emission characteristics of gaseous pollutants were studied. The results indicated that the temperature of first combustion chamber can be maintained at 550–650 °C without external heating, while in the final stage a burner was used to realize the burnout of material. The temperature of the second combustion chamber was always lower than that of the first combustion after the burner stopped working. The concentration of CO emission in flue gas was high due to the low disposal efficiency of the mobile incinerator, while NOX and SO2 emission concentrations were far below the standard limit value (GB 18484-2001).

Study on the brewing industry waste combustion

The combustion of the waste from the brewing industry was investigated. Using the elemental analyzer and standard techniques, the elemental composition and technical characteristics of the studied sample were determined. The ignition and combustion of samples were carried out in a combustion chamber at heating medium temperatures (Tg) withinthe range of 500-700 °C. Gas-phase combustion products were analyzed using an in-line gas analyzer. The minimum ignition temperature of the sample was 337 °C. With an increase in the temperature Tg, a significant decrease in the ignition delay time of the sample was observed (by 9.7 times). The combustion process was accompanied by the formation of an intense flame near the sample surface. It was also found that, with increasing temperature of heating medium, the concentration of CO emission decreased with an inverse increase in the extremum value of CO2 emission.

A deep learning approach to real-time CO concentration prediction at signalized intersection

Vehicle exhaust emissions at signalized intersections are the essential source of traffic-related pollution to pedestrians. Therefore, it is critical to predicting traffic emissions, especially the hazardous CO gas, with practical and accurate methods. However, the CO emission and concentration at crosswalks can be influenced by the complex traffic conditions in a complicated way, making the prediction of CO concentration a challenging task for traditional statistical models. To this end, a hybrid machine learning framework is proposed in this study to investigate the concentration of CO emissions at pedestrian crosswalks. The proposed method firstly ranks key influencing factors with a random forest approach. Then a prediction model with Multi-Variate Long Short-Term Memory (LSTM) neural networks based on the selected factors is developed. Data is collected at the field intersection for model training and validation. The autoregressive integrated moving average (ARIMA), support vector machines (SVM), radial basis functions network (RBFN), nonlinear vector autoregressive (VAR) and gated recurrent unit (GRU) neural network are selected as the benchmark models to verify the performance of the proposed model. The Root Mean Square Errors (RMSE), Mean Absolute Error (MAE) and R square are calculated to evaluate the performance of models comprehensively. The results indicated that the proposed model overwhelms the benchmark models in terms of prediction accuracy.

Gaseous Emissions from a Seagoing Ship under Different Operating Conditions in the Coastal Region of China

Pollution caused by ship emissions has drawn attention from various countries. Because of the high density of ships in ports, channels, and anchorages and their proximity to the densely populated areas, ship emissions will considerably impact these areas. Herein, a Chinese seagoing ship is selected and a platform is established for monitoring the ship emissions to obtain detailed characteristics of the ship’s nearshore emissions. The ship navigation and pollution emission data are obtained under six complete operating conditions, i.e., berthing, manoeuvring in port, acceleration in a channel, cruising, deceleration before anchoring, and anchoring. This study analyzes the concentrations of the main emission gases (O2, NOX, SO2, CO2, and CO) and the average emission factors (EFs) of the pollution gases (NOX, SO2, CO2, and CO) based on the engine power under different operating conditions. Results show that the change in O2 concentration reflects the load associated with the main engine of the ship. The NOX, SO2, and CO2 emission concentrations are the highest during cruising, whereas the peak CO emission concentration is observed during anchoring. The average EFs of NOX and SO2 based on the power of the main engine are the highest during cruising, and those of CO2 and CO are the highest after anchoring. The ship EFs are different during acceleration and deceleration. By comparing the EFs along the coast of China and the global EFs commonly used to perform the emission inventory calculations in China, the NOX EFs under different operating conditions is observed to be generally lower than the global EFs under the corresponding operating conditions. Furthermore, the SO2 EF is considerably affected by the sulfur content in the fuel oil and the operating conditions of the ship. The average CO2 EFs are higher than the global EFs commonly used during cruising, and the CO EFs are higher than the global EFs under all the conditions. Our results help to supplement the EFs for this type of ship under different operating conditions, resolve the lack of emission data under anchoring conditions, and provide data support to conduct nearshore environmental monitoring and assessment.

Combustion Performance and Ash Compositions during Biomass/Semi-Coke Blended Fuel Oxy-Fuel Circulating Fluidized Bed Combustion

Co-combustion biomass with semi-coke under oxy-fuel combustion is a promising way to reduce CO₂ emission and achieve the integrated utilization of biomass and semi-coke. To provide hints on the further industrial utilization, cornstalk was co-combusted with Shenmu semi-coke under oxy-fuel combustion atmospheres in a 50 kW circulating fluidized bed (CFB) test rig, of which the operating parameters can be well controlled. Results showed that semi-coke can achieve stable combustion under an oxy-fuel combustion atmosphere with 30% inlet oxygen concentration. Although inferior to that of cornstalk/coal blended fuel, the combustion performance (ignition and pollutants emission) of cornstalk/semi-coke blended fuel was superior to that of unblended semi-coke. In addition, the increase in the blending ratio of cornstalk or inlet oxygen concentration under the oxy-fuel combustion atmosphere was conducive to reduce the emission concentrations of CO, N₂O, and NO. K tended to release into the gas phase during co-combustion with the semi-coke process, especially under a high blending ratio. High CaO content in semi-coke or coal would result in enrichment of S in bottom ash and circulating ash, which, in turn, inhibited the reaction between S-containing species and KCl, while Cl would accomplish almost total release from fuel, and then it would be enriched in deposits.

Influence of feeding position and post-combustion air arrangement on NOx emission from circulating fluidized bed combustion with post-combustion

To explore the influences of different feeding position and post-combustion air (PCA) arrangement on combustion and original NOx emission characteristics of Shenmu semi-coke, the experiments were carried out on a new circulating fluidized bed (CFB) test platform, which was composed of a CFB and a post-combustion chamber (PCC). The experimental results showed that the feeding position of loop seal could effectively reduce original NOx emission and CO emission concentration in comparison to the conventional coal feeding position of furnace. The NOx emission concentration was 60.3 mg/m3 with single stage PCA. As the grading number of PCA increased, NOx emission can be gradually reduced, eventually falling to 49.6 mg/m3 with triple stages PCA. However, for CO emission, the double stages PCA were able to minimize CO emission. In addition to grading number of PCA, an appropriate injection position of PCA was also helpful for CO burnout. For double stages PCA, the two PCA nozzles should be arranged in the middle of the PCC. According to the above research results, the best feeding position and PCA distribution mode to achieve ultra-low original NOx emission (<50 mg/m3) were obtained.

Effect of Dominant Fatty Acid Esters on Emission Characteristics of Waste Animal Fat Biodiesel in CI Engine

This present study aims in understanding the influence of dominant fatty acid esters of waste animal fat biodiesel on its emission characteristics in CI engine. Biodiesel was produced from waste animal fat by means of base catalysed transesterification; and Ethyl oleate (40.21%), ethyl palmitate (25.36%) and ethyl stearate (16.87%) were characterized as dominant fatty acid esters using GC spectra. Test samples were prepared for these ester molecules based on their availability, in addition to biodiesel blend and plain diesel and were tested for their emission levels in single cylinder four stroke CI engine using flue gas analyser. High exhaust gas temperature was contributed by Ethyl oleate (1.15% lesser than biodiesel), as a result of low cetane number due to unsaturation and high viscosity. Likewise, the increased carbon chain length and unsaturation of ethyl oleate (2.55% lesser than biodiesel) resulted in high concentration of CO emission for biodiesel whereas high CO2 emission concentration was because of ester molecules with increased carbon chain length (stearate and Oleate esters). Reduced NOX emission for biodiesel was as a result of higher cetane number from ethyl stearate (CN=86.83) and ethyl palmitate (CN=86.55), which reduced its ignition delay thereby moderating the heat release rate. In addition, long carbon chained ester molecules (oleate and stearate esters) in biodiesel consumed more oxygen content for improving overall rate of combustion while increased HC emission was explained by unsaturation in biodiesel because of ethyl oleate (on average ,50 PPM).

Emissions Characteristics of Hazardous Air Pollutants from the Incineration of Sacrificial Offerings

The incineration of sacrificial offerings generates numerous hazardous air pollutants, including particulate matter (PM), CO, SO2, NOx and non-methane hydrocarbons (NMHC), which has significant effects on the environment and human health. However, due to the concealment of sacrificial offerings incineration, the emission of such pollutants has not received sufficient attention. Relevant quantification of the emission, emission factors and pollution control measures for this pollution source are lacking. To address these problems, herein, we quantified the particulate matter and its chemical composition and the emission levels of gaseous pollutants, including SO2, NOx, NMHC and CO, by performing incineration experiments of four typical sacrificial offerings (Joss paper, Funeral wreath, Taoist paper art and Yuanbao paper), and obtained the emission factors and emission characteristics for the incineration of sacrificial offerings. Therefore, this study lays the foundation and provides support for establishing an emission inventory of the air pollutants from the incineration of sacrificial offerings and introducing corresponding pollution control measures. The results show that the emission concentrations of CO and total suspended particulate (TSP) from the incineration of sacrificial offerings greatly exceed the emission standard, with averages of 621.4 mg m−3 and 142.9 mg m−3 at 11% oxygen content, respectively. The average emission factors of SO2, NOx, NMHC, CO, PM10 and PM2.5 for the incineration of the four offerings are (0.47 ± 0.17) kg t−1, (2.46 ± 0.35) kg t−1, (5.78 ± 2.41) kg t−1, (32.40 ± 8.80) kg t−1, (4.23 ± 0.71) kg t−1 and (2.62 ± 0.48) kg t−1, respectively, among which the emission intensities of NMHC and CO are relatively high. Among the different types of sacrificial offerings, the overall average emission factor of air pollutants generated from the incineration of Yuanbao paper is the highest, which is mainly due to the low burning efficiency and the coating material. For the chemical composition of the particulate matters, ions, OC, EC and metal elements account for proportions of the PM2.5 at (23.55 ± 10.37) %, (29.74 ± 9.95) %, (14.83 ± 6.55) % and (13.45 ± 4.88) %, respectively, indicating that the organic pollution is severe

The prediction of heat efficiency and pollutant emission of non-rated loaded condensing heat exchangers

In order to study the working conditions of condensing heat exchangers under non-rated load conditions, the orthogonal test method was conducted on the condensing gas water heaters by experiment firstly in this paper. Eighty groups of the experimental data about the relationship between the design variables and the object functions were obtained, among them, the design variables include excess air coefficient, flue gas flow, water flow and water flow temperature, and the objective functions include heat exchanger efficiency, NOx and CO emission concentration. The above experimental data were divided into two groups for the training and prediction of neural networks. Here two neural networks of BP artificial neural network (BPNN) and generalized regression neural network (GRNN) will be used to predict the heat efficiency and pollutant emission of condensate heat exchanger at partial load rate. The results show that both BPNN and GRNN structures achieve the required prediction accuracy, and the prediction accuracy of GRNN is higher than that of BPNN. The condensing heat exchanger can achieve higher heat exchanger efficiency and lower concentration of NOx and CO emission at the 90–100% load rate. When the load rate is lower than 30% or higher than 100%, the heat efficiency of the heat exchanger is decreased, and the concentration of pollutant emission is increased rapidly.

The impact of biofuel properties on emissions and performances of a micro gas turbine using combustion vibrations detection

The use of pure vegetable oils in Micro Gas Turbine can damage the injection system or the combustion chamber causing undesired vibrations. An ideal solution would consist in having an available tool able to forecast and/or follow in real time the vibrational state of the combustion device. The present paper describes tests performed on a low emission Micro Gas Turbine for power generation, fueled with different liquid fuels, including commercial diesel oil and its blends with pure rapeseed oil. A particular attention was paid both on the emissions and on the measurements of the micro vibrational distributions and their correlation under the different fueling conditions using a new signal processing based on a nonlinear method and chaos analysis. We observed that the overall behavior of the MGT fueled with the blends was good, and the emission concentrations of CO, NOx and Total Particle Matter were comparable to the pure diesel oil ones. Moreover, the chaos analysis and the proposed methodology came out as a possible tool for the real-time characterization of the combustion process of the MGT and to individuation of the fuel supplied.

富氧燃烧不同煤粉粒径配比对CO、NO浓度影响

富氧燃烧不同煤粉粒径配比对CO、NO浓度影响

Experimental study on the performance, combustion and emission characteristics of a high compression ratio heavy-duty spark-ignition engine fuelled with liquefied methane gas and hydrogen blend

The aim of this paper investigated the performance, combustion and emission characteristics of a high compression ratio heavy-duty spark ignition engine fuelled with liquefied methane gas (LMG) and different hydrogen blends under at low engine speed. In this study, a compression ignition engine was modified to inject hydrogen and LMG using port fuel injection in spark ignition mode. The results showed that the brake thermal efficiency increased with increasing percentage of hydrogen energy content. The equivalent fuel efficiency value dramatically decreased with increasing load and slightly decreased with increasing percentage of hydrogen energy content. In-cylinder pressures of all the blends with hydrogen are higher than that only LMG fuel. The heat release rate shifted to the top dead center (TDC) and the 50% combustion location was remarkably advanced with the increasing of hydrogen energy content. Furthermore, the maximum pressure rise rate increased and the location of the maximum pressure rise rate shifted to the TDC with increasing of hydrogen energy content, respectively. NOx emission dramatically increased with increasing load and hydrogen energy content, respectively. Conversely, HC and CO2 emission concentration declined with increasing of hydrogen energy content. CO emission concentration kept low value at all the loads.