The electrical heating experiments on oil shale sample from Huadian of Jilin were carried out by the pyrolysis method at three different heating rate 2℃/min, 5 ℃/min and 10 ℃/min in the temperature range of 30℃ -...The electrical heating experiments on oil shale sample from Huadian of Jilin were carried out by the pyrolysis method at three different heating rate 2℃/min, 5 ℃/min and 10 ℃/min in the temperature range of 30℃ -750℃. Heating rate 2 ℃/rain is considered low, while intermediate one covers the range 5 ℃/min and high heating rate is 10℃/min. The controlling parameters studied were the final pyrolysis temperature and the influence of the heating rate as well as type. The heating rate has an important effect on the pyrolysis of oil shale and the amount of residual carbon obtained therefore. It is found that increasing the heating rate and py- rolysis temperature also increases the production of oil and the total weight loss. Higher heating rates resulted in higher rates of accumulation. The rate of oil and water collection passed through the maximum of different heat- ing rates at different pyrolysis temperatures. Heating rate affected density, oil conversion and oil yield.展开更多
Samples of five types of coal and oil shale from the Daqing region have been subjected to co-pyrolysis in different blending ratios with thermo-gravimetry （TG）, given a heating rate of 30 ℃/min to a final tem- pera...Samples of five types of coal and oil shale from the Daqing region have been subjected to co-pyrolysis in different blending ratios with thermo-gravimetry （TG）, given a heating rate of 30 ℃/min to a final tem- perature of 900 ℃. Investigations on pyrolysis of mixing coal and oil shale in different proportions were carried out, indicating that the main scope of weight loss corresponding to hydrocarbon oil and gas release was between 350 and 550 ℃. At higher temperatures, significant weight loss was attributed to coke decomposition. Characteristic pyrolysis parameters of blends from oil shale and the high ranked XZ coal varied with the blending ratio, but oil shale dominated the process. At the same blending propor- tions, highly volatile medium and low ranked coal of low moisture and ash content reacted well during pyrolysis and could easily create synergies with oil shale. Medium and high ranked coal with high mois- ture content played a negative role in co-pyrolysis.展开更多
A better understanding of two-phase flows with evaporation allows leading to an optimal design of evaporators. For that purpose, numerical simulations are very useful. In this paper, a numerical study has been carried...A better understanding of two-phase flows with evaporation allows leading to an optimal design of evaporators. For that purpose, numerical simulations are very useful. In this paper, a numerical study has been carried out in order to model and simulate the combination of a two-phase flow with evaporation in a vertical tube. The VOF （volume-of-fluid） multiphase flow method and a phase-change model for the mass transfer have been used. For an accurate modeling, the effect of axial conduction has been also taken into account using a conjugate heat transfer model. Since thermal oscillations are undesirable as they can lead to the failure of the tube, flow instabilities have also been analyzed, using FFT （fast Fourier transforms）, in order to comprehend their behavior and influence. A control study of the flow instabilities in the tube is also presented. For that purpose tube inlet temperature has been varied using a gain control parameter.展开更多
文摘The electrical heating experiments on oil shale sample from Huadian of Jilin were carried out by the pyrolysis method at three different heating rate 2℃/min, 5 ℃/min and 10 ℃/min in the temperature range of 30℃ -750℃. Heating rate 2 ℃/rain is considered low, while intermediate one covers the range 5 ℃/min and high heating rate is 10℃/min. The controlling parameters studied were the final pyrolysis temperature and the influence of the heating rate as well as type. The heating rate has an important effect on the pyrolysis of oil shale and the amount of residual carbon obtained therefore. It is found that increasing the heating rate and py- rolysis temperature also increases the production of oil and the total weight loss. Higher heating rates resulted in higher rates of accumulation. The rate of oil and water collection passed through the maximum of different heat- ing rates at different pyrolysis temperatures. Heating rate affected density, oil conversion and oil yield.
基金the financial support from the National Natural Science Foundation of China (No. 51104159)the Special Found of Central Universities for Basic Scientific Research Projects (No. 2011QNB06)
文摘Samples of five types of coal and oil shale from the Daqing region have been subjected to co-pyrolysis in different blending ratios with thermo-gravimetry （TG）, given a heating rate of 30 ℃/min to a final tem- perature of 900 ℃. Investigations on pyrolysis of mixing coal and oil shale in different proportions were carried out, indicating that the main scope of weight loss corresponding to hydrocarbon oil and gas release was between 350 and 550 ℃. At higher temperatures, significant weight loss was attributed to coke decomposition. Characteristic pyrolysis parameters of blends from oil shale and the high ranked XZ coal varied with the blending ratio, but oil shale dominated the process. At the same blending propor- tions, highly volatile medium and low ranked coal of low moisture and ash content reacted well during pyrolysis and could easily create synergies with oil shale. Medium and high ranked coal with high mois- ture content played a negative role in co-pyrolysis.
文摘A better understanding of two-phase flows with evaporation allows leading to an optimal design of evaporators. For that purpose, numerical simulations are very useful. In this paper, a numerical study has been carried out in order to model and simulate the combination of a two-phase flow with evaporation in a vertical tube. The VOF （volume-of-fluid） multiphase flow method and a phase-change model for the mass transfer have been used. For an accurate modeling, the effect of axial conduction has been also taken into account using a conjugate heat transfer model. Since thermal oscillations are undesirable as they can lead to the failure of the tube, flow instabilities have also been analyzed, using FFT （fast Fourier transforms）, in order to comprehend their behavior and influence. A control study of the flow instabilities in the tube is also presented. For that purpose tube inlet temperature has been varied using a gain control parameter.
