For equipment insulation, the temperature between the two layers of the insulation is the maximum allowable operation temperature for the outer layer material, and is subject to the temperature change in both inner and outer layers. 对于设备保温而言,两层保温材料夹缝处的温度即为外层保温材料的最大可能使用温度,而该温度会同时受到内、外层保温材料厚度变化的影响。
ψ and η are approximately presented as a linear function of temperature T. so η e is a parabolic function of operation temperature and has a maximum exergy efficiency η emax corresponding to an optimum operation temperature. ψ和η可分别表示为T的线性函数,因此ηe&T是一条抛物线,并存在着最大(火用)效率和相应的最佳运行温度。