Q	Heat transfer rate, kW
T	Temperature, K
$\dot{m}$	Mass flow rate, kg/s
$c_p$	Specific heat, kJ/(kg K)
W	Power, kW
$\dot{E}$	Exergy, kW
$\dot{I}$	Exergy destruction rate, kW
h	Specific enthalpy, kJ/kg
i	Interest rate
$Re$	Reynolds number
$Pr$	Prandtl number
$Fr$	Froude number
$D_e$	Equivalent diameter, m
$Bo$	Boling number
$C_{\mathrm{BM}}$	Bare module equipment cost
$C_{\mathrm{p}}$	Bare module cost for ambient pressure and carbon steel construction
$F_{\mathrm{P}}$	Pressure factor
K	Contraction and expansion loss coefficients
U	Total heat transfer coefficient, W/m${}^2$ K
A	Heat transfer area, ${\mathrm{m}}^2$
$LT$	Life time
t	time, h
k	Thermal conductivity, W/m${}^2$ K
g	Acceleration of gravity, $\mathrm{m}/{\mathrm{s}}^2$
$\delta$	Thickness of tube or plate, m
$\eta$	Efficiency, %
$\alpha$	Heat transfer coefficient, W/m${}^2$ K
$\mu$	Viscosity, Pa·s
$\rho$	Density, kg/m${}^3$
$\xi$	Relative closeness
$\gamma$	Latent heat, J/kg