What term defines the ratio of total heat supplied by fuel to total heat absorbed by boiler water?

The term that defines the ratio of total heat supplied by fuel to total heat absorbed by boiler water is "thermal efficiency." This term is crucial as it provides a measure of how effectively a boiler converts the energy from fuel into useful heat energy that is utilized for heating the water.

Thermal efficiency is calculated by taking the useful heat output (the heat absorbed by the boiler water) and dividing it by the heat input (the total heat supplied by the fuel). A higher thermal efficiency indicates that a greater proportion of the energy from the fuel is being converted into useful heat, thereby minimizing waste and maximizing performance.

Understanding thermal efficiency is essential for assessing boiler performance, optimizing fuel consumption, and improving overall energy efficiency in heating systems. This concept is particularly important for operators and engineers working with boilers, as it directly impacts operational costs and environmental considerations.

In contrast, other terms such as thermal capacity, boiler efficiency, and heat exchange ratio, while related to the efficiency and performance of a boiler, do not specifically define this particular ratio as thermal efficiency does.