本文针对提供低温热能的两种不同情况(一种是热流体的流量不变,另一种是供热量不变),指出了二者在发电方案中从热经济性的角度对工质的某些热物理性质提出了不同的甚至相反的要求,继而根据热力学基本原理结合低温热能发电的特性导出了上述两种情况下确定工质的最佳蒸发温度和最佳冷却水温升(最佳凝结温度)的四个计算式和相应的修正系数。通过对各种工质和各种方案的计算,证实了这些计算式不但是可靠的,而且很精确。这些计算式将为低温热能发电方案的热力计算提供方便,并大大节省计算工作量。 In this paper, two different situations of providing low temperature heat energy (one is that the flow rate of the hot fluid is constant and the other is the heat supply constant) are pointed out. In the power generation scheme, Some thermophysical properties put forward different or even opposite requirements. Based on the basic principles of thermodynamics combined with the characteristics of low-temperature thermal power generation, the optimal evaporation temperature and the optimal cooling water temperature rise for the above two conditions are derived Condensation temperature) of the four formulas and the corresponding correction factor. Through the calculation of various working fluids and various schemes, it is confirmed that these formulas are not only reliable but also accurate. These formulas will facilitate the thermal calculation of low-temperature thermal power generation schemes and greatly reduce the computational workload.