Study on the Thermodynamic Properties in the Anomalous Region of Supercritical Water

LIU Jinqi; YIN Wei; WANG Guoxiang; LI Dong; WANG Yueshe; CHEN Bin; SHI Jinwen

doi:10.7652/xjtuxb202607001

您当前的位置：

首页 >

文章列表页 >

Study on the Thermodynamic Properties in the Anomalous Region of Supercritical Water

Special Topic Frontier Applications of Supercritical Fluids | 更新时间：2026-07-09

- Study on the Thermodynamic Properties in the Anomalous Region of Supercritical Water
- Journal of Xi'an Jiaotong University Vol. 60, Issue 7, Pages: 1-12(2026)
- 作者机构：
  
  西安交通大学动力工程多相流国家重点实验室，710049，西安
  阿克伦大学机械工程系，44325，美国阿克伦
- 作者简介：
- 基金信息：
- DOI：10.7652/xjtuxb202607001
  CLC： TK121
- Received：28 September 2025，
  
  Published：10 July 2026
- 稿件说明：
移动端阅览
LIU Jinqi, YIN Wei, WANG Guoxiang, et al. Study on the Thermodynamic Properties in the Anomalous Region of Supercritical Water[J]. Journal of Xi'an Jiaotong University, 2026, 60(7): 1-12.
DOI：

LIU Jinqi, YIN Wei, WANG Guoxiang, et al. Study on the Thermodynamic Properties in the Anomalous Region of Supercritical Water[J]. Journal of Xi'an Jiaotong University, 2026, 60(7): 1-12. DOI： 10.7652/xjtuxb202607001.

摘要

利用超临界水独特的溶解与反应特性可以高效转化生物质制氢，但超临界水在临界区存在物性剧烈波动导致的热力学特性复杂多变、过程不稳定等问题，严重影响系统效率及稳定性。为揭示超临界水在临界邻域的异常热力学行为，提出了一种利用吉布斯自由能高阶导数进行判别的分析方法。通过引入等压比热参数、等压膨胀参数、等温压缩参数及其无量纲形式，结合Matlab编程调用REFPROP软件中的流体数据，分析水在等压、等温过程中3个参数随相对温度、相对压力的变化规律，得到各参数的极值线轨迹，并综合绘制水在超临界状态下的区域相图。该方法能够准确捕捉异常区域内物性突变特征：在相对温度

= 1.02、相对压力

= 1.1附近，等压热容达到常规区间的约3.4倍，而等温压缩率提升近2倍，为此将水在超临界区域划分为类液态、类气态和类固态，为工况优化提供了明确边界。通过将超临界水的热力学分析与实际工况进行综合分析，可确保操作温度和压力不会进入高风险异常区域，有效减少了设备故障和不稳定性。

Abstract

The unique dissolution and reaction characteristics of supercritical water（SCW）facilitate the efficient conversion of biomass into hydrogen.However，drastic fluctuations in physical properties within the near-critical region lead to complex thermodynamic properties and process instabilities，which significantly hinder system efficiency and stability.To elucidate these anomalous thermodynamic behaviors，an analytical method based on the higher-order derivatives of the Gibbs free energy was proposed.I

sobaric heat capacity，isobaric expansion coefficient，and isothermal compressibility，along with their dimensionless forms，were analyzed using fluid data extracted from REFPROP via Matlab.The variations of these three parameters of water with respect to reduced temperature（

）and reduced pressure（

）during isobaric and isothermal processes were systematically investigated.The trajectories of the extrema for each parameter were identified，based on which a comprehensive regional phase diagram of water in the supercritical state was plotted.The results demonstrate that the proposed method accurately captures the abrupt changes in physical properties within the anomalous region.Specifically，at

≈1.02 and

≈1.1，the isobaric heat capacity reaches approx.3.4 times its value in the conventional region，while the isothermal compressibility increases nearly twofold.Accordingly，the supercritical region of water is classified into liquid-like，gas-like，and solid-like regimes，providing explicit boundaries for the optimization of operating conditions. Integrating the thermodynamic analysis of SCW with practical conditions ensures that operating temperatures and pressures avoid high-risk anomalous regions，thereby effectively reducing equipment failure and process instability.

关键词

Keywords

references

徐硕, 余碧莹.中国氢能技术发展现状与未来展望[J].北京理工大学学报(社会科学版), 2021, 23 (6):1-12.

Xu Shuo, Yu Biying.Current development and prospect of hydrogen energy technology in China [J].Journal of Beijing Institute of Technology(Social Sciences Edition), 2021, 23(6):1-12.

郭烈锦, 吕友军, 金辉.太阳能聚焦供热的生物质超临界水气化制氢技术经济性分析[C]//2013年年会暨工业气体供应技术论坛论文集(上海)会议论文集. 2014:49-53.

Wang Guoxiang, Almara L M, Prasad V.Thermodynamic analysis of anomalous region, critical point, and transition from subcritical to supercritical states:application to van der Waals and five real fluids [J]. Physics of Fluids, 2024, 36(2):026105.

马栋梁, 周涛, 冯祥, 等.超临界水临界区域判定方法研究[J].化学通报, 2019, 82(2):151-157.

Ma Dongliang, Zhou Tao, Feng Xiang, et al.Study on critical region determination method of supercritical water [J].Chemistry, 2019, 82(2):151-157.

王艳, 徐进良, 李文,等.超临界Lennard-Jones流体结构特性分子动力学研究[J].物理学报, 2020, 69(7):070201.

Wang Yan, Xu Jinliang, Li Wen, et al.Molecular dynamics study on structural characteristics of Lennard-Jones supercritical fluids [J].Acta Physica Sinica, 2020, 69(7):070201.

Mao Shang, Zhou Tao, Wei Dong, et al.Heat transfer characteristics of supercritical water in channels: a systematic literature review of 20 years of research [J]. Applied Thermal Engineering, 2021, 197:117403.

Hu Zhanchao, Zhang Xinrong.Piston effect induced by cross-boundary mass diffusion in a binary fluid mixture near its liquid-vapor critical point [J].International Journal of Heat and Mass Transfer, 2019, 140:691-704.

Marrone P A, Hong G T.Corrosion control methods in supercritical water oxidation and gasification processes [J]. The Journal of Supercritical Fluids, 2009, 51(2):83-103.

Marrone P A, Cantwell S D, Dalton D W.SCWO system designs for waste treatment:application to chemical weapons destruction [J].Industrial & Engineering Chemistry Research, 2005, 44(24):9030-9039.

Yanik J, Ebale S, Kruse A, et al.Biomass gasification in supercritical water:Ⅱ effect of catalyst [J]. International Journal of Hydrogen Energy, 2008, 33(17):4520-4526.

Yanik J, Ebale S, Kruse A, et al.Biomass gasification in supercritical water: part 1 effect of the nature of biomass [J].Fuel, 2007, 86(15):2410-2415.

Yong T L K, Matsumura Y.Reaction kinetics of the lignin conversion in supercritical water [J].Industrial & Engineering Chemistry Research, 2012, 51 (37):11975-11988.

Azadi P, Farnood R.Review of heterogeneous catalysts for sub-and supercritical water gasification of biomass and wastes [J].International Journal of Hydrogen Energy, 2011, 36(16):9529-9541.

Pinkard B R, Gorman D J, Tiwari K, et al.Supercritical water gasification: practical design strategies and operational challenges for lab-scale, continuous flow reactors [J].Heliyon, 2019, 5(2):e01269.

Toledano A, Serrano L, Labidi J.Organosolv lignin depolymerization with different base catalysts [J]. Journal of Chemical Technology and Biotechnology, 2012, 87(11):1593-1599.

Antal M J Jr, Allen S G, Schulman D, et al.Biomass gasification in supercritical water [J].Industrial & Engineering Chemistry Research, 2000, 39 (11):4040-4053.

Kritzer P.Die Korrosion der nickel-basis-legierung 625 unter hydrothermalen bedingungen:einfluß der parameter temperatur, druck, pH-wert und anwesenheit von sauerstoff sowie der anionen chlorid, sulfat, nitrat und phosphat auf das korrosionsverhalten [D]. Heidelberg, Germany: Heidelberg University, 1998.

Lu Libo, Liu Shi, Fang Zijian, et al.Mechanism of salt deposition, nucleation and separation in the supercritical water gasification of black liquor [J].Chemical Engineering Journal, 2025, 506:159914.

Li Xinyang, Jin Yuliang.Thermodynamic crossovers in supercritical fluids [J].Proceedings of the National Academy of Sciences, 2024, 121(18):e2400313121.

Xu L, Kumar P, Buldyrev S V, et al.Relation between the Widom line and the dynamic crossover in systems with a liquid-liquid phase transition [J].Proceedings of the National Academy of Sciences, 2005, 102(46):16558-16562.

Simeoni G G, Bryk T, Gorelli F A, et al.The Widom line as the crossover between liquid-like and gas-like behaviour in supercritical fluids [J].Nature Physics, 2010, 6(7):503-507.

Banuti D T, Raj u M, Ihme M.Between supercritical liquids and gases-Reconciling dynamic and thermodynamic state transitions [J].The Journal of Supercritical Fluids, 2020, 165:104895.

Ha M Y, Yoon T J, Tlusty T, et al.Widom delta of supercritical gas-liquid coexistence [J].The Journal of Physical Chemistry Letters, 2018, 9(7):1734-1738.

Yoon T J, Ha M Y, Lee W B, et al.Probabilistic characterization of the Widom delta in supercritical region [J]. Journal of Chemical Physics, 2018, 149(1):014502.

Prasad V, Kakroo K, Banerjee D.Existence of supercritical “liquid-like”state in subcritical region, optimal heat transfer enhancement, and argon as a nonreacting, noncorroding SC heat transfer fluid [J].Heat Transfer Research, 2022, 53(9):1-27.

Nishikawa K, Kusano K, Ayusawa Arai A, et al. Density fluctuation of a van der Waals fluid in supercritical state [J].The Journal of Chemical Physics, 2003, 118(3):1341-1346.

Nishikawa K, Arai A A, Morita Ta.Density fluctuation of supercritical fluids obtained from small-angle X-ray scattering experiment and thermodynamic calculation [J].The Journal of Supercritical Fluids, 2004, 30(3):249-257.

Prasad V, Wang Guoxiang, Haque R S, et al.New phase diagrams with anomalous region, supercritical solid-like state, liquid phase boundary, and Dwij point [J].The Journal of Supercritical Fluids, 2025, 224:106644.

Views

下载量

CSCD

Alert me when the article has been cited

提交

Tools

Publicity Resources

Study on the Corrosion Mechanisms of Nickel-Based Alloys in Hydrogen-Containing Supercritical Water

Reaction Mechanism and Hydrogen Production Efficiency of Aluminum-Water Reaction in Sub- and Supercritical Water

Kinetic Study on Supercritical Water Co-Gasification of Coal and Sewage Sludge

A Molecular Dynamics Study on the Kinetic Mechanism of Methane to Hydrogen in Supercritical Water

Mechanism and Optimal Control Strategy for Hysteresis in Rapid Dehumidification Response of Indirect Thermal Systems in Electric Vehicles

Related Author

ZHAO Jinqi

YIN Wei

WANG Guoxiang

LI Dong

WANG Yueshe

CHEN Bin

SHI jinwen

WANG Hao

Related Institution

Department of Mechanical Engineering, The University of Akron, Akron

State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University

Northwest Institute of Nuclear Technology

BYD Automotive Limited Company

State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University

⁰