Feedwater heaters are used in thermal and nuclear power plants to improve the efficiency of the power cycle. They use steam extracted from the turbine to preheat the water entering the economizer section of the boiler. Several stages of feedwater heating are normally used, with the final stages operating at high temperature and very high pressure. The mechanical demands on the equipment are severe and the heaters are critical to the efficient generation of electricity.
Feedwater heaters come in two basic forms, the tubesheet-type heater and the header-type heater. The header-type heater was previously popular (especially in Europe and for power plants with variable output demands), but has recently been largely superseded by the tubesheet heater. Both types of heater are highly specialised heat exchangers, and demand rigorous engineering in their design, manufacture, operation and maintenance.
Power Plant Engineering have in-depth experience with both types of heater and can provide advice on all aspects of design and operation. Previous projects have included troubleshooting of performance, advice on replacement of obsolete heaters, investigation of mechanical failures and supervision of inspection and repair.
Steam surface condensers are used in all steam cycle plants (nuclear, fossil and combined cycle) to condense the steam exhaust from the turbine ready for return to the boiler. The condenser generates a vacuum which increases the amount of energy extracted from the steam by the turbine. The condenser also serves as a low-pressure collection point for various vent and drain streams within the plant.
Depending on the type of plant and its location, the condenser may be either water-cooled or air-cooled. Although these two types perform the same function, the equipment involved is very different. Water-cooled condensers are relatively compact and can utilise a variety of water sources (sea water, river water etc.) to provide cooling. Air-cooled condensers are large structures which use fans to blow air over the heat transfer surface. Many modern plants use air-cooled condensers as water resources are usually limited by environmental controls.
Power Plant Engineering has extensive experience in the design, fabrication, operation and maintenance of steam surface condensers. Previous projects have included leak testing, advice on re-tubing, vacuum system analysis and turnaround inspections.