In this work, we demonstrate why classical thermo-mechanical exergy functions are incorrect below the environmental reference pressure, since they result in too small or even negative values. We present new derivations for thermo-mechanical exergy for fluids at any temperature or pressure above or below the environmental reference temperature and pressure. We then present new pressure–enthalpy–exergy diagrams of real chemicals to visually demonstrate the results.

中文翻译：

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低于环境压力的物质的热机械火用

在这项工作中，我们证明了为什么经典的热机械火用函数在低于环境参考压力时不正确，因为它们会导致太小甚至负值。我们提出了在高于或低于环境参考温度和压力的任何温度或压力下流体的热机械火用的新推导。然后，我们展示真实化学品的新压力-焓-火用图，以直观地展示结果。