A temperature feasibility constraint is an important part of multistream heat exchanger (MSHE) modeling. However, temperature feasibility of an MSHE model makes a numerical issue when a physical property package is used to obtain highly accurate temperature-enthalpy relationships in equation-oriented modeling environment. To resolve the issue, this study proposes a new MSHE model with enthalpy feasibility using the fact that enthalpy is a monotonically increasing function of temperature. A natural gas liquefaction process, called a single mixed refrigeration process, is optimized using the proposed MSHE model under an equation-oriented modeling environment with a physical property package as a case study.

温度可行性约束是多流热交换器（MSHE）建模的重要组成部分。但是，当在面向方程的建模环境中使用物理属性包来获得高精度的温度-焓关系时，MSHE模型的温度可行性会产生一个数值问题。为了解决这个问题，本研究提出了一种新的具有焓可行性的MSHE模型，其原理是焓是温度的单调增加函数。在具有物理属性包的以方程为导向的建模环境下，使用拟议的MSHE模型对天然气液化过程（称为单混合制冷过程）进行了优化，以案例为研究对象。