Development of a Heating Process of a Slag-Tapping Hole by Syngas Burning in a 150 t/d Entrained-Bed Coal Gasifier

摘要

Integrated coal gasification combined cycle systems are expected to raise the power generation efficiency of coal-fired power plants. In Japan, coal gasifiers are required to treat various kinds of coal imported from many countries because almost all of the coal is imported from abroad. In an entrained-bed coal gasifier, the slag-tapping hole must be heated adequately to discharge the molten slag. Thus, a heating technique has been developed to heat the hole from below, without using any auxiliary fuels. The technique is to burn the syngas, which descends through the hole at high temperature, by supplying oxygen from a pair of nozzles facing each other installed just below the hole. In this study, a design procedure to heat the hole by those nozzles was developed through thermal and flow simulations and actual gasification tests in a 150 t/d entrained-bed coal gasifier of pilot scale.