The steam generating unit described herein is a balance draft coal-fired Babcock & Wilcox (B&W) Spiral Wound Universal Pressure (SWUP™) boiler. The boiler contains a dry-bottom furnace, superheater, reheater, economizer, and air heater components. This unit is designed for both base load and variable pressure load cycling operation as well as on-off cycling operation. | Sumitomo Corporation for EVNGENCO1 Duyen Hai 3 Extension, 1 x 660 MWnet Power Project July 7, 2014 SUPERCRITICAL SPIRAL WOUND BOILER OVERVIEW The steam generating unit described herein is a balance draft coal-fired Babcock & Wilcox (B&W) Spiral Wound Universal Pressure (SWUP™) boiler. The boiler contains a dry-bottom furnace, superheater, reheater, economizer, and air heater components. This unit is designed for both base load and variable pressure load cycling operation as well as on-off cycling operation. Figure 1 below depicts a typical B&W SWUP™ boiler. Figure 1: B&W once-through spiral wound universal pressure (SWUP™) boiler for pulverized coal firing with SCR B&W Proposal P-043049 PROPRIETARY AND CONFIDENTIAL Copyright © 2014 Babcock & Wilcox Power Generation Group, Inc. All rights reserved Page 1 of 5 Sumitomo Corporation for EVNGENCO1 Duyen Hai 3 Extension, 1 x 660 MWnet Power Project July 7, 2014 A Unique Design- Ideal for Rapid Load Changes A unique feature of the B&W SWUP™ boiler is that the furnace tubes, from the lower furnace inlet headers to a location near the furnace arch, are spiral wound around the furnace instead of vertical. In this arrangement, each tube in the furnace passes through similar heat absorbing areas, keeping heat absorption from tube to tube reasonably uniform. This, results in a reduced fluid temperature variation leaving the furnace which minimizes thermal upset that can restrain rapid load change. Additionally, the ability of this design to operate at variable load pressure is further enhanced by using a startup system with a recirculation pump (up to the once-thru point only) specifically designed for rapid startup. Furthermore, since the tubes are at an angle, there are fewer flow paths compared to vertical tube geometry which increases mass flux in the tubes. A high mass flux is desired within the tube to maintain nucleate boiling during subcritical operation and to provide enhanced cooling .
