Abstract
Once-through steam generator (OTSG) is usually used in the integrated nuclear power plants which require smaller volume and better effect of heat transfer. The double-tube OTSG component which is composed of straight tube outside and helical tube inside is presented in this paper. The primary fluid is divided into two parts, one is in the inner tube and the other is in the gap among outer tubes. The flow distribution ratio of the primary fluid obviously affects the heat transfer. Thus, the problem of optimization emerges, i.e. how to find an optimal flow distribution ratio with a maximum heat exchange. Analyzed the effects of the distribution ratio on heat transfer, the optimal distribution ratio is obtained by the constrained nonlinear optimization method. Subsequently, the optimal distribution ratio is achieved by a throttling set in the entrance of the inner tube. The result is in substantial agreement with the literature.
