Scholarlink

<p>Understanding and mastering the compression temperature rise laws of working fluids can provide scientific references for the selection of compression working fluids in various energy systems, from large-scale compression energy storage, high-efficiency heat pumps to advanced power cycles. Previous investigations have predominantly attempted to correlate this phenomenon with macroscopic properties such as density or the isentropic exponent. However, these approaches remain largely empirical and lack a unified physical mechanism, which limits their predictive capability across diverse working fluids and operational conditions. This study addresses this fundamental gap by identifying molecular degrees of freedom (DOF) as the governing factor underlying the isentropic compression temperature rise. Through rigorous theoretical derivation and systematic analysis across various thermodynamic states (atmospheric pressure, subcritical gaseous, subcritical liquid, near-critical, and far-critical), we demonstrate an inverse relationship between temperature rise and molecular DOF, following the sequence: monatomic&gt;diatomic&gt;triatomic&gt;polyatomic working fluids, independent of initial thermodynamic conditions. This relationship originates from the molecular-level energy partition mechanism, wherein higher DOF enables greater distribution of compression work into rotational and vibrational modes rather than translational kinetic energy, which directly governs temperature. A generalized quantitative correlation between compression temperature rise and molecular DOF is established. Comprehensive three-dimensional CFD simulations validate our theoretical framework, showing remarkable agreement with errors below 1%. This work provides a universal microscopic principle for predicting compression behavior, offering fundamental insights for working fluid selection in advanced energy systems.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Molecular Degrees of Freedom: The Key Factor Governing Compression Temperature Rise in Working Fluids

  • 期刊论文

  • 发表日期：

    2026年7月25日

查看全文
  • Enhui Sun,
  • Lingkun Chen,
  • Zhenyu Leng,
  • Bin Li,
  • Jinliang Xu,
  • Yu Yang,
  • Tai Wang

摘要

Understanding and mastering the compression temperature rise laws of working fluids can provide scientific references for the selection of compression working fluids in various energy systems, from large-scale compression energy storage, high-efficiency heat pumps to advanced power cycles. Previous investigations have predominantly attempted to correlate this phenomenon with macroscopic properties such as density or the isentropic exponent. However, these approaches remain largely empirical and lack a unified physical mechanism, which limits their predictive capability across diverse working fluids and operational conditions. This study addresses this fundamental gap by identifying molecular degrees of freedom (DOF) as the governing factor underlying the isentropic compression temperature rise. Through rigorous theoretical derivation and systematic analysis across various thermodynamic states (atmospheric pressure, subcritical gaseous, subcritical liquid, near-critical, and far-critical), we demonstrate an inverse relationship between temperature rise and molecular DOF, following the sequence: monatomic>diatomic>triatomic>polyatomic working fluids, independent of initial thermodynamic conditions. This relationship originates from the molecular-level energy partition mechanism, wherein higher DOF enables greater distribution of compression work into rotational and vibrational modes rather than translational kinetic energy, which directly governs temperature. A generalized quantitative correlation between compression temperature rise and molecular DOF is established. Comprehensive three-dimensional CFD simulations validate our theoretical framework, showing remarkable agreement with errors below 1%. This work provides a universal microscopic principle for predicting compression behavior, offering fundamental insights for working fluid selection in advanced energy systems.