【摘要】 以量子化学从头算法(Ab initio quantum chemistry)和密度泛函理论(DFT)为理论基础,采用广义梯度近似(GGA)及PW91算法,对煤灰沉积初始层中的含钠矿物质Na2SO4的电子结构和热力学性质进行了计算。通过声子态密度法计算了Na2SO4的热力学性质(熵、热容、焓和吉布斯自由能),并对所得数据组图。通过Na2SO4与菱镁矿的热力学性质的对比分析,表明Na2SO4在高温区更易熔融并在受热面形成结渣初始层,从而导致水冷壁沾污结渣。更多还原

【Abstract】 The structural and thermodynamic properties of Na2SO4 with high content of sodium in the initial layer of ash were calculated based on the quantum chemistry Ab initio calculation and density functional theoretical(DFT),using the generalized gradient approximation(GGA) and PW91 algorithm.Then the entropy,heat capacity,enthalpy and Gibbs free energy of Na2SO4 by the phonon spectra state density were calculated and the images accor-ding to the data were made.Finally the comparative of the thermodynamic properties of Na2SO4 and magnesite was analyzed.The results indicate that Na2SO4 is easier to melt in the high temperature zone and form a slagging initial layer on the heating surface,which can lead to the formation of fouling and slagging on the waterwall.更多还原