Due to its djstinctive advantages

gas-gas heat pipe exchanger used for recovery of waste heat is now being widely ac-cepted by the industry and its optimal design is therefore highly evaluated. From the point of view of economy

this paperdescribes a design procedure in which net economic gain S is set as the optimal object and economic coefficient Y as the ob-ject function. By taking the two conditions-the previous defined and undefined hot flow temperatures at exit as one prob-lem and by adopting the mixed penalty function with the cyclic coordinate variation

the author has established a computerprogramme for the optimal design of gas-gas heat pipe heat exchanger according to speific conditions.