利用微扰理论推算实际气体的定容比热和定压比热

CALCULATION OF VOLUMETRIC SPECIFIC HEAT CAPACITY AND ISOBARIC SPECIFIC HEAT CAPACITY OF REAL GASES USING PERTURBATION THEORY

将统计热力学中的微扰理论应用于推算实际气体的定容比热和定压比热,并通过改进,提高了计算精度.从对部分普通气体和低碳烃类气体的定容比热和定压比热的计算来看,其计算结果与文献值符合良好.应用本文所提出的方法只需知道实际气体的几个参数,就能推算出其在给定状态下的定容比热和定压比热,因而具有较强的通用性和较好的实用价值.

The volumetric specific heat capacity and isobaric heat capacity of real gases were calculated using perturbation theory in statistical thermodynamics and the accuracy was improved by using an improved method inthis paper. The calculation of numerous points of the saturated and superheated vapor of real fluids such as N2, O2,SO2,CO,CO2,CH4,C2H2, C2H4, C2H6, C3H8, etc., showed that the results were in good agreement with the values reported in literature and improved accuracy was achieved in comparison with the general L-K equation of state and the equation of specific heat capacity in literature. The specific heat capacity at constant volume and the specific heat capacity at constant pressure of real gases at a given state can then be calculated only when the critical parameters Tc, Vc and acentric factor are known. Although this method is not fit for direct calculation for its complexity, it is efficient, simple and practical in computerized calculation.