Question 586General Subjects - Assistant Engineer

The correct answer is D) The evaporator itself is used as a main engine heat recovery device for use in generating fresh water at the evaporator. The evaporator is the component that utilizes the waste heat from the main engine's cooling system to generate fresh water through the process of distillation. The main engine jacket water is circulated through the evaporator, where the heat is transferred to the seawater or brackish water in the evaporator, causing it to evaporate and then condense as fresh water. This heat recovery process is a key function of the evaporator in a marine fresh water generation system. The other answer choices are incorrect because the main engine jacket water heater, cooler, and the evaporator standby heater are not the primary heat recovery devices for generating fresh water in this system. They may serve other support functions, but the evaporator itself is the main component responsible for utilizing the main engine's waste heat to produce fresh water.