Transient Characteristics of Vertical High Pressure Feed Water Heaters

Abstract

Transient characteristics of heat exchangers have been studied and developed by Masubuchi. And it seems that the discussions for these problems are completed, but those results are far from actual application for some cases.
In this paper, vertical high pressure feed water heaters which are equipped in the steam propulsion plant are considered, because these responses influence the boiler feed water temperature directly.
The heating medium in a shell side presents character changes, i.e. desuper heating-steam, condensing-saturated vapour, and drain cooling-drain. This means the heat exchange model for it is very complicated and makes difficult to take fundamental relations.
The heat exchange model here is very simplified and represented only by condensing model including all other sections. The theoretical analysis is tried and developed especially with the aid of the results by Hotta and Imaeda.
As the result of the theoretical analysis and on board tests, followings are concluded.
1) The transfer functions which describe the transient responses are known and confirmed.
2) The response is much depend upon the characteristics of associated final control elements rather than one of the heat exchanger itself.