Abstract
The exhaust gas economizer is one of the most efficient measures for the exhaust heat recovery of the Diesel ship. In responding the strong demand of the fuel conservation, various advanced plants with turbo-generating system have been developed and have been successfully installed onto the Diesel ships in service. In spite of the difficulties of the decreasing gas temperature, the decreasing gas flow rate, the severe deterioration of fuel grade, etc., those newly developed plants have achieved the remarkable improvement of the exhaust heat recovery rate in comparison with the plants in the age of 1969. The main technological features of the advanced plants are the followings, that is, the first is the introduction of two-or three-stage pressure system, the second is the use of extended heating surface, and the third is the designs of various countermeasures against the low temperature fouling and corrosion. These features, however, have brought not only desirable improvements but also undesirable impacts such as the damage of generating tubes, the soot fire etc. Although most of impacts have already been overcomed, the soot fire, which is the most impressive and serious fault, is still troubling the people concerned and is demanding the reliable solution.
