CAJ | 학술논문

烃类pVT性质的精细表征对能源动力、化工等领域应用有重要价值，临界区热力性质描述是难点之一.本文建立了烷烃(C1-C20)的跨接比容平移Soave-Redlich-Kwong (SRK)(跨接VTSRK)状态方程，在SRK状态方程的基础上引入了比容平移和跨接方法，以改善饱和液相密度和近临界区域热力学性质的计算精度，方程参数被表达为物质临界参数和偏心因子的函数.比较结果表明，跨接方程对烷烃(C1-C20)饱和蒸气压、饱和气相密度、饱和液相密度的计算平均偏差分别为1.01%、1.83%和0.93%，显著优于原方程，单相区和近临界区的pVT性质计算精度也比原状态方程有较大改善.进一步将方程推广到环烷烃(环丙烷、环戊烷和环己烷)和苯、甲苯的计算，也获得了较好效果，验证了方程的预测能力.
경류pVT성질적정세표정대능원동력、화공등영역응용유중요개치，림계구열력성질묘술시난점지일.본문건립료완경(C1-C20)적과접비용평이Soave-Redlich-Kwong (SRK)(과접VTSRK)상태방정，재SRK상태방정적기출상인입료비용평이화과접방법，이개선포화액상밀도화근림계구역열역학성질적계산정도，방정삼수피표체위물질림계삼수화편심인자적함수.비교결과표명，과접방정대완경(C1-C20)포화증기압、포화기상밀도、포화액상밀도적계산평균편차분별위1.01%、1.83%화0.93%，현저우우원방정，단상구화근림계구적pVT성질계산정도야비원상태방정유교대개선.진일보장방정추엄도배완경(배병완、배무완화배기완)화분、갑분적계산，야획득료교호효과，험증료방정적예측능력.
Accurate predictions of the pVT properties of alkanes are very important since they are associated with many fundamental aspects in energy, power engineering, and chemical engineering fields. Predicting the properties of alkanes in the critical region, however, remains chal enging. In this work, a crossover volume translation Soave-Redlich-Kwong (SRK) equation of state (EoS) was developed for C1 to C20 alkanes, in which volume translation and crossover methods were combined to improve the description of saturated liquid densities and thermodynamic properties in the critical region. The parameters of the crossover equation are set as constants or expressed as functions of critical parameters and the acentric factor. Comparisons showed that the average deviations of the crossover volume translation SRK equation results for C1 to C20 alkanes were 1.01%for vapor pressure, 1.83%for saturated vapor density, and 0.93%for saturated liquid density, and these deviations are much lower than those obtained with the SRK equation of state. In addition, prediction results for properties in the single phase region and the critical region from the crossover equation were in better agreement with experimental data than those from the SRK equation. The crossover volume translation SRK equation was also extended to the pVT properties of cycloalkanes (cyclopropane, cyclopentane, and cyclohexane), benzene and toluene. The prediction results were also satisfactory, demonstrating the superior predictive ability of the crossover equation of state.