The impact of turbine guide vanes on a three-dome combustor’s lean blowout limit and blowout process was experimentally investigated. The parameters studied include the presence of the turbine guide vanes or not and the blockage ratio of turbine guide vanes. It is shown that the presence of turbine guide vanes and an increase in the blockage ratio increase the lean blowout fuel-to-air ratio. From the images of flame spontaneous emission captured by the high-speed camera, the coupling of the combustor with turbine guide vanes can alter the sequence of the blowout among the three domes, and localized tiny flame lumps have been observed to develop into larger flames during lean blowout. However, flames within the combustor are established independently near blowout, and no reignition is observed. Furthermore, the turbine guide vanes have been found to shorten the duration of the blowout process and enhance the likelihood of blowout by increasing the lean fuel-to-air ratio.

The green transition of power systems relies on the accurate measurement of the economic cost associated with the deep peak-shaving process in coal-fired power plants. To evaluate the variation in the coal consumption rate during low-load operation, a model of a 300 MW coal-fired unit was established, with less than 1% deviation from the actual operation value. The results indicate that the coal consumption rate at 20% load can increase to 1.48 times the full-load value. When the excess air coefficient is reduced by 0.3 at low-load conditions, between 40% and 20% load, the exhaust gas temperature is reduced by approximately 5°C, leading to a decrease in the coal consumption rate. In addition, elevating the steam temperature to the design value can reduce the coal consumption rate by 6% to 13%, and increase the inlet temperature of Selective Catalytic Reduction (SCR) process by 10°C. Improving the turbine efficiency during peak-shaving significantly reduces the coal consumption cost, and the enhancement of the mean steam temperature is an efficient approach. This study offers a theoretical reference for the retrofitting, design and economic operation of coal-fired units in peak-shaving, thereby supporting energy system transitions.

Waste plastics, with their high hydrogen-to-carbon (H/C) atomic ratios, can act as hydrogen donors during coal pyrolysis, thereby enhancing tar yield and quality. Thus far, a study has been conducted on the co-pyrolysis characteristics of coal and waste plastic, along with a rapid prediction method for tar yield. An experimental system for the co-pyrolysis of coal and waste plastic is established to examine the distribution patterns of pyrolysis products, such as gas, tar, and char, at varying temperatures and coal-to-waste plastic ratios. The results indicate a significant synergistic effect during the co-pyrolysis of coal and plastic waste. As the blending ratio of waste plastic increases, the tar yield also increases, with the value of the synergistic effect parameter initially rising and then falling. As the blending ratio continues to increase, the formation of a liquid phase becomes more prevalent on the surface of coal particles during the pyrolysis process, which inhibits tar release and leads to a gradual decrease in the positive synergistic effect of the waste plastic on tar yield. Based on these findings, a rapid prediction model for tar yield has been developed using neural networks and optimized with a Genetic Algorithm (GA) and Particle Swarm Optimization (PSO), achieving a 10.52% reduction in the average prediction error under training conditions. The proposed model is utilized to predict the tar yield for new conditions in the database, with the relative error generally maintained within (–20%, 30%), demonstrating good accuracy and utility.

Dialkyl carbonate is a potential renewable alternative fuel for transportation. This study, utilizing a constant volume combustion chamber, investigates the characteristics of spray auto-ignition of dialkyl carbonate when mixed with diesel fuel. Measurements of combustion pressures and heat release rates during fuel spray combustion were conducted at varied conditions of fuel blending percentage, ambient temperature and pressure, injection pressure, and oxidizing atmospheres. The study also derives and compares ignition and combustion delays from pressure traces for different fuel blends. Results indicate that blending dialkyl carbonate with diesel fuel reduces ignition tendency, supported by delayed pressure rise and heat release processes with increased blending percentage of dialkyl carbonate. Further, at lower blending percentages of dialkyl carbonate, fuel ignition and combustion delays are insensitive to changes in injection pressure, but fuel combustion delay is significantly shortened with increased injection pressure at higher blending percentages. Finally, in an oxidizing atmosphere of CO₂/O₂ mixtures, fuel spray combustion processes are retarded, and this retardance is noticeable at higher dialkyl carbonate blending percentages.

The oxidation of propane (C₃H₈) was investigated in a jet-stirred reactor under equivalence ratios (Φ) of 0.5‒3.0 within 675‒1025 K at 1.2 MPa. Mole fraction profiles of 14 species were identified and quantified by online gas chromatographs (GC) and gas chromatography-mass spectrometry (GC-MS). The alkenes including n-butene (C₄H₈-1) and 1,3-butadiene (1,3-C₄H₆) were newly identified compared with previous oxidation studies of C₃H₈. A detailed kinetic model consisting of 426 species and 1933 reactions was developed with reasonable predictions against the experiment data. In general, the peak mole fractions of light alkanes shift toward higher values with increasing Φ, while opposite trends are observed for inorganic species. The species of light alkanes increase with the increasing Φ. Rate-of-production analysis indicates that C₃H₈ is mainly consumed by H-abstractions with OH radicals to produce normal-propyl (nC3H7) and iso-propyl (iC₃H₇) radicals under all conditions. Sensitivity analysis shows that H₂O₂(+M)=2OH(+M) plays a promoting role in C₃H₈ consumption, while reaction 2HO₂=H₂O₂+O₂ plays an inhibiting role. Particular attention was paid to the effect of pressure and Φ on C₃H₈ consumption at 1.2–10.0 MPa and with Φ ranging from 0.1 to 3.0. It is found that the onset reaction temperature of C₃H₈ decreases with increasing pressure. The Rate-of-production (ROP) analysis indicates that the reactions related to pressure-dependent result in decreased onset reaction temperature and C₄ species would be more formed at lower pressure. In addition to the present experiment data, the model can reasonably predict the ignition delay times and laminar burning velocities reported in the literature.