Spiral tube steam generator

The SG for the LFR-AS-200 is characterized by a spiral-tube bundle with a 530°C lead inlet temperature and 400°C temperature at the outlet. The SG unit, as well as all other in-vessel components, is removable for in-service inspection, or replacement. The upper part of the spiral tube steam generator (STSG) is bolted to the reactor roof, and there is no equipment welded to the reactor vessel. 

For steam parameters of 26 MPa/590 °C, the temperatures at the transition from spiral to vertical wall are not higher than those in the walls of plants built in the 1990s [12]. Under these steam conditions, the spiral wall can therefore still be built from the material 13CrMo4—5. In the area of the vertical tubes above the transition, however, allowable limits may be exceeded, since in this area of the steam generator, a considerable heat radiation at relatively high steam temperatures is present. 

Steam generators Integrated in the reactor vessel and removable. Preferred option spiral tubes... 

The steam from the generator is passed through a copper spiral (Fig. 15) which is heated by a Bunsen flame, and which has a side tube attached for a thermometer. This tube is placed on the exit tube, and as far away as possible from the flame. 

Reformed gas is cooled to the shift inlet temperature of 250°C by generating steam (4). The CO shift reaction is carried out in a single stage in the isothermal shift reactor (5), internally cooled by a spiral wound tube bundle. To generate MP steam in the reactor, de-aerated and reheated process condensate is recycled. 

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