Improved sprayed water boiler design for steam production

Abstract

The lengthy time required for conventional boilers to attain a steady state, their sizable size, the substantial pressure drop, and their high cost are all disadvantages. The objective of this study was to develop a novel design for a boiler to achieve better performance based on a sprayed water boiler (SWB) through injectors with a specific spray rate in a near-atomized form over tubes containing hot gases. As the water temperature in the SWB is equal to the temperature of the water sprayed by the injectors, the temperature difference between the hot gases and the water is higher than in the conventional boiler. A parametric study was conducted to investigate the main parameters affecting the boiler performance, such as the steam quantity and quality, the time required to reach the steady state condition, the size of the boiler, and the drop pressure on the hot-gas side. The results showed that the size of the SWB was significantly smaller than that of a conventional boiler. When generating steam of the same quantity and quality, the size of the SWB is one-third of the conventional size. This reduces the manufacturing costs of the boiler and the pressure drop of the hot gases inside the boiler. It was also found that the thermal efficiency of the SWB was higher, and the start-up time to reach a steady state of operation was less than 1% of the time required for the conventional boiler. To close the gaps in the theoretical design, an experimental test should be performed.