All the leading boiler-making countries have their own boiler and pressure vessel codes. These codes evolved after the early boilers experienced disastrous explosions on account of failure of PPs due to the rise of internal pressure. The boiler codes are essentially extensions of pressure vessel codes customized for fired equipment. It should be clear that […]

Feed pumps absorb the most auxiliary power in a power plant, and hence power savings here make a big difference in actual kilowatt hour (kWh) terms. • Reduction of SH and RH losses is a normal measure to reduce pump power. • Adding minimum test block margins consistent with good operating practice is another important […]

• Lowering the gas velocities over the tubes can reduce gas pressure drop in the boiler. But this reduces the heat transfer rates and makes the boiler larger and More expensive. A balance between the heat transfer rate and the pressure drop is necessary, which is largely taken care of by following the recommended optimum […]

• All the walls of the furnace are to be fully water-cooled, as achieved regularly in modern boilers by membrane walls. Refer to Chapter 6. • The boiler along with ducts and piping is insulated such that the surface tempera­ture is not more than 20-25°C over the prevailing ambient temperature.

• Unburnt loss indicates how well the firing equipment and furnace are sized and matched such that — The three Ts—time, temperature, and turbulence—are adequately addressed. — Heat release rates of the firing equipment and the volumetric heat release rate of furnace are judiciously selected to burn the fuel optimally. — Air pressures, temperatures, and […]

There are two important components to the stack loss: (1) exit gas temperature and (2) excess air at the last heat trap. • Exit gas temperature should be as low as possible, consistent with the avoidance of low-temperature gas side corrosion as depicted in Figure 6.36. This works out to a temperature of ~140°C (285°F) […]

The goals of good boiler design include: • Customization to meet specific requirements • Optimization of performance • Good build quality for reliable operation Performance optimization is the most important, mainly by lowering of the boiler losses and auxiliary power consumption. The losses that can be lowered are only stack and unburnt losses, and the […]

• Boiler specification and purchase are very important functions as the life of a boiler plant exceeds 30 years. Proper purchase can save huge amounts in capital and run­ning expenditure and an error can be disastrous. • Because a boiler is a customized item, it costs a lot of time and effort for the boil­ermaker […]

There are major differences in the way the HRSGs behind GTs are tested compared to conventional boilers, even WHRBs. The HRSG is treated as part of a combined cycle power plant (CCPP) instead of a stand-alone steam generator. • For HRSGs behind GTs PTC 4.4 is applied and not PTC 4. • The performance test […]

PTC 4.1 does not cover the waste heat and special-purpose boilers for which testing procedures must be evolved and agreed. Waste heat recovery boilers are components of process plants, and certain expectations besides steam production need to be met. Over the years, each process has undergone a certain method of testing and evaluating performance. The […]