Question 61 QMED04 - Boiler Technician-Watertender

The Correct Answer is D **Explanation for Option D (637.42°F):** The problem asks for the superheater outlet temperature ($T_{out}$) given the initial saturated steam pressure and the temperature elevation (superheat). 1. **Determine the Saturation Temperature ($T_{sat}$):** We must first find the temperature at which water boils (saturates) at the given pressure, 400 psia, using the steam tables (Illustration SG-0004). * Referring to the saturated steam tables for 400 psia: $T_{sat} = 444.59^\circ\text{F}$. 2. **Calculate the Superheater Outlet Temperature ($T_{out}$):** The superheater elevates the steam temperature by the given amount (superheat). The outlet temperature is the saturation temperature plus the temperature elevation. * Temperature Elevation ($\Delta T$) = $192.83^\circ\text{F}$ * $T_{out} = T_{sat} + \Delta T$ * $T_{out} = 444.59^\circ\text{F} + 192.83^\circ\text{F}$ * $T_{out} = 637.42^\circ\text{F}$ Therefore, the superheater outlet temperature is $637.42^\circ\text{F}$. **Explanation for Incorrect Options:** * **A) 192.83°F:** This is the value of the temperature elevation (the amount of superheat) itself, not the final outlet temperature. * **B) 247.31°F:** This value is likely the saturation temperature corresponding to a different, lower pressure (approximately 30 psia) and is irrelevant to the calculation at 400 psia. * **C) 444.59°F:** This is the saturation temperature ($T_{sat}$) of the steam at 400 psia. It represents the temperature *entering* the superheater, not the elevated temperature *exiting* it.