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TECHNOLOGY<br />
As nuclear power plants are frequently operated according to<br />
Unlike in U-type heaters, the water and steam sides in header-type<br />
heaters are separated by two thick-walled pipes, the inlet and outlet<br />
headers, instead of by a tubesheet. Moreover, the heat exchanger<br />
tubes are arranged in a snake shape instead of U shape, generally<br />
in 3 or 4 water passes through the shell area.<br />
A complete high-pressure heater train generally consists of three<br />
header-type heaters and a separate desuperheater. The heaters<br />
are installed vertically in most cases and only rarely horizontally.<br />
Header with snake tubes<br />
Fabrication of header-type heaters is more complex than for U-type<br />
heaters. Special attention is paid to the connections between the<br />
headers and snake tubes, which are welded together indirectly<br />
using nipples. The automated welding process used is especially<br />
reliable. In the over 1,200 header-type heaters manufactured<br />
since 1935, with around one million tubes, only 15 tubes had to<br />
be plugged.<br />
Nipple<br />
Snake tube<br />
Header<br />
Header-to-tube joint<br />
BALCKE-DÜRR AMERICAS<br />
A DIVISION OF SPX COOLING TECHNOLOGIES, INC.<br />
7401 W 129 STREET<br />
OVERLAND PARK, KANSAS 66213<br />
UNITED STATES<br />
913 664 7428<br />
bdinfousa@spx.com<br />
balcke-duerr.com<br />
In the interest of technological progress,<br />
all products are subject to design and/or<br />
material change without notice.<br />
©2009 SPX Cooling Technologies, Inc.<br />
Printed in USA | brochure_na_46<br />
Investing in header-type heaters instead of U-type heaters usually<br />
pays off in power plants with nominal capacities from about 500<br />
MW. Above this threshold, investment costs for U-type heaters<br />
escalate since they must be arranged in two trains instead of in<br />
a single train. Consequently, the cost of equivalent header-type<br />
heaters is generally exceeded. Maintenance costs for U-type<br />
heaters are much higher in large power plant units or in cycling<br />
operation because heaters of this type are susceptible to damage<br />
and require frequent repairs and not seldom must even be<br />
completely replaced.<br />
APPLICATION<br />
450 MW Avedöre 2 coal-fired power plant, Denmark:<br />
The four header-type heaters were manufactured in the Neubeckum<br />
facility and have been operating since 2000.<br />
Tube bundle in the manufacturing facility<br />
950 MW Niederaussem K lignite-fired power plant, Germany:<br />
Equipping one of the world’s most modern lignite-fired power<br />
plants (BoA 1) with header-type heaters (2000).<br />
Header-type heater during installation in the power plant
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