新疆昌吉油页岩与煤混合燃烧特性研究

Co-combustion characteristics of Changji oil shale and coal

为了充分利用新疆昌吉地区低热值的油页岩,将油页岩和准东煤进行混合燃烧,利用热重分析仪(TG)、灰熔点测定仪、电感耦合等离子体发射光谱仪(ICP-OES)等手段对其混合燃料的燃烧特性、灰熔点变化及Na的挥发进行充分研究。结果表明:随着灰中碱性氧化物和酸性氧化物质量比(B/A)的降低(油页岩比例升高),混合燃料的着火温度和燃尽温度逐渐升高,可燃性和燃烧特性降低;随着B/A的降低,混合燃料的灰熔点先下降后上升,当B/A为1.67时,灰中各组分比例正好位于低温共融区域,导致灰熔点降低;随着B/A的降低,Na元素的挥发呈先快速下降后缓慢上升的趋势,当燃烧温度为850℃、B/A为1.44时,Na挥发降至最低;油页岩可将煤中的Na固定至灰中,有效地抑制了Na挥发,为油页岩的高效利用提供了新途径。

In order to make full use o f the low calorific value oil shale in Changji area o f Xinjiang, the oil shale and Zhundong coal were co-fired, and the combustion characteristics, ash fusion point and sodium volatilization were fully studied by means o f thermogravimetric analyzer (TG), ash melting point tester and inductively coupled plasma emission spectrometer (ICP-OES). The experimental results show that, with the decrease o f mass ratio of basic oxides to acidic oxides (B/A) in the ash, namely with the increase o f blending ratio o f oil shale, the ignition temperature and burnout temperature o f the mixed fuel increased gradually, so the flammability and combustion characteristics decreased.With the decrease o f B/A, the ash melting point o f the mixed fuel decreased at first and then rose, when the B/A reached 1.67, the proportion o f each component in the ash was located in the low temperature co-melting region, which led to a decrease in ash melting point. With the decrease o f B/A, the volatilization o f sodium element decreased rapidly and then slowly rose. When the combustion temperature was 850 C and the B/A was 1.44, the sodium volatilization reached the minimal value. The oil shale can fix the sodium element into the ash, which effectively suppressed the volatilization o f N a. The result provides a new way for utilization o f Changji oil shale.