高校地质学报
高校地質學報
고교지질학보
GEOLOGICAL JOURNAL OF CHINA UNIVERSITIES
2013年
3期
447-455
,共9页
超临界水%PVT性质%状态方程%分子动力学模拟
超臨界水%PVT性質%狀態方程%分子動力學模擬
초림계수%PVT성질%상태방정%분자동역학모의
supercritical water%PVT properties%equation of state%molecular dynamics simulation
1990年以来,超临界水的PVT实验数据和分子动力学模拟数据已延伸到很高的温度和压力。文中详细评价了这些数据的质量。国际水和水蒸汽性质学会所推出的1995年版的水的状态方程(IAPWS95)被选作评价的可靠基础,同时辅以其适当的外延。分析结果表明,Zhang and Duan (2005)的模拟数据和Abramson and Brown (2004)通过声速实验值反演得到的PVT数据与目前最精确的水的PVT数据吻合得很好,但后者有较小的系统偏差。其它几组数据都有较大的系统偏差或不确定度。其中,Belonoshko and Saxena (1991)的模拟数据P-T范围很宽,但不确定度很大,而且有显著的系统偏差。Brdoholt and Wood (1993)的模拟数据也有显著的系统偏差。随着压力的增加,这两组模拟数据的体积偏差都有由正转负的趋势,其中后者尤为显著,而且在高压下离散性很弱,因而易于校正。Withers et al.(2000),Brodholt and Wood (1994)和Frost and Wood (1997)的实验数据都有明显的正偏差,其中前一组的偏差较小,后两组的偏差较大,原则上均可近似地校正。Larrieu and Ayers (1997)的数据总体不确度较大,其中偏差较小的数据仅限于特定的温度和压力,其它数据的偏差没有明显的规律。这些结果应当有助于上述新数据的正确使用和进一步优化。
1990年以來,超臨界水的PVT實驗數據和分子動力學模擬數據已延伸到很高的溫度和壓力。文中詳細評價瞭這些數據的質量。國際水和水蒸汽性質學會所推齣的1995年版的水的狀態方程(IAPWS95)被選作評價的可靠基礎,同時輔以其適噹的外延。分析結果錶明,Zhang and Duan (2005)的模擬數據和Abramson and Brown (2004)通過聲速實驗值反縯得到的PVT數據與目前最精確的水的PVT數據吻閤得很好,但後者有較小的繫統偏差。其它幾組數據都有較大的繫統偏差或不確定度。其中,Belonoshko and Saxena (1991)的模擬數據P-T範圍很寬,但不確定度很大,而且有顯著的繫統偏差。Brdoholt and Wood (1993)的模擬數據也有顯著的繫統偏差。隨著壓力的增加,這兩組模擬數據的體積偏差都有由正轉負的趨勢,其中後者尤為顯著,而且在高壓下離散性很弱,因而易于校正。Withers et al.(2000),Brodholt and Wood (1994)和Frost and Wood (1997)的實驗數據都有明顯的正偏差,其中前一組的偏差較小,後兩組的偏差較大,原則上均可近似地校正。Larrieu and Ayers (1997)的數據總體不確度較大,其中偏差較小的數據僅限于特定的溫度和壓力,其它數據的偏差沒有明顯的規律。這些結果應噹有助于上述新數據的正確使用和進一步優化。
1990년이래,초림계수적PVT실험수거화분자동역학모의수거이연신도흔고적온도화압력。문중상세평개료저사수거적질량。국제수화수증기성질학회소추출적1995년판적수적상태방정(IAPWS95)피선작평개적가고기출,동시보이기괄당적외연。분석결과표명,Zhang and Duan (2005)적모의수거화Abramson and Brown (2004)통과성속실험치반연득도적PVT수거여목전최정학적수적PVT수거문합득흔호,단후자유교소적계통편차。기타궤조수거도유교대적계통편차혹불학정도。기중,Belonoshko and Saxena (1991)적모의수거P-T범위흔관,단불학정도흔대,이차유현저적계통편차。Brdoholt and Wood (1993)적모의수거야유현저적계통편차。수착압력적증가,저량조모의수거적체적편차도유유정전부적추세,기중후자우위현저,이차재고압하리산성흔약,인이역우교정。Withers et al.(2000),Brodholt and Wood (1994)화Frost and Wood (1997)적실험수거도유명현적정편차,기중전일조적편차교소,후량조적편차교대,원칙상균가근사지교정。Larrieu and Ayers (1997)적수거총체불학도교대,기중편차교소적수거부한우특정적온도화압력,기타수거적편차몰유명현적규률。저사결과응당유조우상술신수거적정학사용화진일보우화。
Since 1990, the PVT data of supercritical water from experiments and molecular dynamics simulations are extended to very high temperatures and pressures. These data are assessed in detail in this work. The equation of state for water developed by the International Association for the Properties of Water and Steam (IAPWS95) is chosen as a reliable basis for the assessment, which is also aided by appropriate extrapolation of the equation. The results suggest that the simulated data of Zhang and Duan (2005) and those of Abramson and Brown (2004) derived from sound velocity measurements agree well with those of the most accurate data of water at present, but the latter has small systematic deviations. The data in the other groups have obvious systematic deviations or uncertainties. The simulated data of Belonoshko and Saxena (1991) have a large P-T range, but they also have large uncertainties and obvious systematic deviations. The simulated data of Brodholt and Wood (1993) also have notable systematic deviations. As pressure increases, the volume deviations of these two groups of simulated data vary from positive to negative, where the deviations in the latter group are particularly obvious, and show very strong pressure dependence features at high pressures, so they are easy to correct. The experimental data of Withers et al. (2000), Brodholt and Wood (1994) and Frost and Wood (1997) have obvious positive deviations, and can be corrected in principle, where the deviations of the first group are small, but those of the latter two are much bigger. Overall, the experimental data of Larrieu and Ayers (1997) have large uncertainties, where small deviations are only limited to the data at specific temperature and pressure, and the deviations of the other data have no obvious regularity. These results should be helpful in the correct use of and further refinement of the above data.