An extensive series of experiments was carried out in order to identify suitable catalysts to boost the reaction rate of wet air oxidation of real textile wastewaters at relatively mild temperature and pressure. Exper...An extensive series of experiments was carried out in order to identify suitable catalysts to boost the reaction rate of wet air oxidation of real textile wastewaters at relatively mild temperature and pressure. Experimental results indicated that all catalysts tested in this investigation had shown an impressive increase in the initial COD and TOC removal rate as well as the COD and TOC removal levels in two hours reaction. Among all the catalysts tested, copper salts were more effective than the rest. Anions of the salt solutions also played a role in the catalytic process with nitrate ions having better effect than sulfate ions. Hence copper nitrates were more effective than copper sulfates. It was also found that a mixture of salts with different metals performed better than either of the component single salt alone.展开更多
Frequency domain spectroscopy(FDS)is widely used for assessing the condition of oil-paper insulated electrical equipment.However,in low temperatures,measurement results often deviate from expected values.This study in...Frequency domain spectroscopy(FDS)is widely used for assessing the condition of oil-paper insulated electrical equipment.However,in low temperatures,measurement results often deviate from expected values.This study investigates the low-temperature dielectric response characteristics of oil-paper insulation under large temperature differences(-60℃ to 30℃),wide frequency ranges(1 mHz-5 kHz)and varying moisture contents(0.41%-3.91%).The mechanisms of low-temperature effects on oil-paper insulation relaxation polarisation are revealed.Further,a novel low-temperature normalisation method and a moisture evaluation method are proposed based on the improved Havriliak-Negami model.Compared to traditional methods,the new approach signifi-cantly enhances the accuracy.The goodness of fit R2 for temperature normalisation improves from 0.9526 to 0.9757,and the error in moisture content evaluation has reached 0.498%.Finally,the novel approach is applied to diagnose the condition of a damped bushing model,demonstrating high potential for practical applications.This study enables condition diagnosis of oil-impregnated electrical equipment in extremely cold environ-ments,filling a critical gap in the field.展开更多
文摘An extensive series of experiments was carried out in order to identify suitable catalysts to boost the reaction rate of wet air oxidation of real textile wastewaters at relatively mild temperature and pressure. Experimental results indicated that all catalysts tested in this investigation had shown an impressive increase in the initial COD and TOC removal rate as well as the COD and TOC removal levels in two hours reaction. Among all the catalysts tested, copper salts were more effective than the rest. Anions of the salt solutions also played a role in the catalytic process with nitrate ions having better effect than sulfate ions. Hence copper nitrates were more effective than copper sulfates. It was also found that a mixture of salts with different metals performed better than either of the component single salt alone.
基金National Natural Science Foundation of China,Grant/Award Number:52477027。
文摘Frequency domain spectroscopy(FDS)is widely used for assessing the condition of oil-paper insulated electrical equipment.However,in low temperatures,measurement results often deviate from expected values.This study investigates the low-temperature dielectric response characteristics of oil-paper insulation under large temperature differences(-60℃ to 30℃),wide frequency ranges(1 mHz-5 kHz)and varying moisture contents(0.41%-3.91%).The mechanisms of low-temperature effects on oil-paper insulation relaxation polarisation are revealed.Further,a novel low-temperature normalisation method and a moisture evaluation method are proposed based on the improved Havriliak-Negami model.Compared to traditional methods,the new approach signifi-cantly enhances the accuracy.The goodness of fit R2 for temperature normalisation improves from 0.9526 to 0.9757,and the error in moisture content evaluation has reached 0.498%.Finally,the novel approach is applied to diagnose the condition of a damped bushing model,demonstrating high potential for practical applications.This study enables condition diagnosis of oil-impregnated electrical equipment in extremely cold environ-ments,filling a critical gap in the field.
