Question

In a steady-flow industrial process, m kg/s of an ideal gas flows through a heater at a constant mass flow rate. It is your job to select a heater that is powerful enough to heat the gas from T i (300 K) to T e (350 K). Your calculation doesn't have to be perfect because you can always adjust the power to the heater slightly, so you decide to assume that specific heats are constant. Which of the following equations would give you the correct power for the heater, and why?

Answer 1

P= m° Cp ( Te - Ti)

Step-by-step explanation:

Given that

Mass flow rate = m° kg/s

Ti= 300 K

Te= 350 K

We know that flow work given as

W= h₂ - h₁

We know that for ideal gas enthalpy is the function of temperature only.

Δh= CpΔT

Cp= Specific heat capacity

ΔT =Change in temperature

So the heater power given as

P = m° ( h₂ - h₁)

P= m° Cp ( Te - Ti)