Norihiko Orita

MITSUBISHI Heavy Industries, Ltd., Technical Headquarters Yokohama Research & Development Center
(1-8-1 Sachiura, Kanazawa-ku, Yokohama 236 Japan)

Abstract

The first stage of waste-fired power generation plants started operation in the 1960s in Europe. At the start, they experienced many troubles caused by high temperature boiler tube corrosion. In order to reduce the troubles, many improvements were made in refuse burning, boiler structure, boiler tube protection and tube materials. Introducing these improved technologies, the U.S.A. began the construction of large-scale waste-fired power generation plants in the late 1970s. In Europe, refuse is identified as a returnable energy source, and many European countries are taking policies to use waste for power generation. Waste fired boilers experience more severe corrosive conditions than fossil fuel fired boilers. Furnace wall boiler tubes are corroded by direct high temperature flame attack; refractory linings on the tube surface are adopted from the early stage of European plants, and a high alloy welded overlay was developed recently in U.S.A.. In order to avoid superheater tube corrosion and erosion, superheated steam temperature was decreased to under 450*C[Celsius degeree] from the 500*C[Celsius degeree] level of the early stage, and gas temperature is maintained under 450*C[Celsius degeree] in the superheater tube section. A new age of boilers is coming up with "Tail End Type" and "Panel Type" superheater tubes.

Key words: waste fired power generation, refuse incinerator, refuse boiler, energy recovery, high temperature corrosion