本文首先利用导热微分方程的綫性性質,說明有内部热源的冷却问题可分解为一个初溫均匀的無热源問题与一个初温为零的有热源問題之和,然后采用拉普拉斯变换求出平面问题的严格数学解答。在这个基础上考虑水温的沿途变化得到空間問题的近似解。并按無因次量制备一套曲线供设计人員查用以避免极其繁重的計算工作。 In this paper, we first use the linear nature of the differential thermal conductivity equation to show that the cooling problem with internal heat source can be decomposed into a heat source problem with a uniform initial temperature and a heat source with zero initial temperature, and then Laplace transform Strict mathematical solution to the plane problem. On this basis, taking into account the water temperature along the way to get the approximate solution to the space problem. And according to the amount of non-dimensional preparation of a curve for designers to check to avoid extremely arduous calculations.