Titanium Tubes for Coastal Power Plant Condensers
Titanium and titanium alloy tubes are widely used in power plant applications covering condensers, cooling systems, piping and tubing, turbine blades, and generator retaining rings, etc. More and more power plants are constructed in coastal areas using seawater as its coolant. Seamless & welded titanium tubes and titanium sheets were firstly introduced to the manufacture of titanium condensers in 1970s. Due to its outstanding corrosion & erosion resistance to sea water and cost effectiveness in long-term run, titanium is superseding copper alloy in coastal power plant applications. Among all titanium and titanium alloys, the ASTM B338 unalloyed titanium Grade 2 is most widely utilized.
ASTM B338 titanium Gr.2 seamless tubes, for a coastal power plant condenser, 1″ x 0.7 mm x 7.805 m.
International Equivalent Standards
- ASTM B338 / ASME SA-338: seamless and welded titanium and titanium alloy tubes for condensers and heat exchangers.
- JIS H4631: titanium and titanium alloys – tubes for heat exchangers.
- GB/T 3625: titanium and titanium alloy tube for condensers and heat exchangers.
Titanium vs. Copper Alloy
The welding of titanium tube sheet for a power plant condenser.
Before titanium was introduced to the industry, copper alloys were commonly chosen for the manufacture of condensers for the coastal power plant application. Why choose titanium over traditional copper alloys? It depends on the comprehensive consideration of quality, total investment, maintenance, working life, and relative facilities. The final total investment is the crucial factor affecting material selection. Generally, titanium has much longer service life and results in much more cost-effective investment than copper alloys. The table below shows the comparison between titanium Grade 2 and copper alloys(C70600 & C71500) for tube material selection of a 125 MW power plant condenser in Mexico.
| Item | Titanium Gr.2 | C70600 | C71500 |
|---|---|---|---|
| Density, g*cm3 | 4.5 | 8.9 | 8.9 |
| Tube Spec., mm | Φ25 x 0.5 x 7575 | Φ25 x 1.0 x 7575 | Φ25 x 1.0 x 7575 |
| QTY, pcs | 11968 | 11968 | 11968 |
| Unit Weight, kg/pc | 1.57 | 5.08 | 5.08 |
| Total Weight, ton | 18.8 | 60.0 | 60.0 |
| USD/kg | 26.66 | 3.00 | 5.00 |
| Initial Total USD | 501333 | 265888 | 304000 |
| Working Life | 40 | 2~3 | 2~4 |
| Ave. Investment / Year, USD | 12533 | 60833 | 76000 |
| Total Investment in 40 Years, USD | 501333 | 2433320 | 3040000 |
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