Planning errors frequently occur due to insufficient knowledge of subsequent operation or because essential requirements for the boiler system have not been properly taken into consideration. With this in mind, it is helpful to verify the plausibility of all existing data together with all those involved in planning. Significant deviations from the basic evaluation can arise, especially for projects running over longer periods.
Oversizing in itself does not represent a problem in terms of continued operation of a boiler system. However, this does increase the likelihood of an uneconomical mode of operation of a system and, due to cycling of the combustion system, high thermal stresses can arise at the flame tube which can reduce the service life.
Oversizing frequently occurs if safety margins are planned at several points. The operator plans from the outset with subsequent expansion in mind, the planner stays on the safe side, and manufacturers design many components with a built-in safety margin.
Info on Maximum steam output
Undersizing poses a significant operating problem. Boilers not equipped with suitable safety functions fall below the standard operating pressure. When this happens, more and more water is carried along in the steam pipe and faults occur due to the enormous fluctuations in water level.
When supplying fuel for gas combustion, the gas flow pressure at full load in particular must be taken into account. If the gas flow pressure is too low, faults will occur in the combustion system. Sometimes the necessary flow pressure at the gas regulation module is forwarded directly to the gas supplier without considering the resistances in the gas line between the gas transfer station and gas regulation module. It must also be ensured that there is enough of a difference between the gas flow pressure, which is necessary for operation and the setting values for the pressure limiting and safety equipment, so that they are not triggered when the double solenoid valves of the combustion system close.
To ensure reliable combustion, it is essential for the supply air apertures in the boiler house to be sufficiently large and also fully open when the burner is in operation. If the supply air is insufficient, this can lead to problems ranging from soot formation through to hard ignition resulting in severe damage to the boiler.
If pipes in danger of freezing, e.g. freshwater lines, are located near the supply air apertures, the risk of frost in the winter must be taken into account.
Extract air apertures must also be provided to avoid large thermal stresses due to an accumulation of heat under the boiler house ceiling. The insulation of boilers, pipework and valves is in fact becoming more and more effective which reduces the thermal output in the boiler house. The residual heat must however still be removed from the boiler house. Electronic switching equipment in particular can fail due to high ambient temperatures.