Unless the material on the second row falls in the scope of "fa" (which, judging by the screenshot you've posted, isn't the case), I would not center the material on the second row with respect to the parentheses on the first row. Instead, I would use a split
environment, as is shown in the screenshot below. Why not center the material on row 2? Because doing so risks "losing it" in the clutter, visually/typographically speaking.

\documentclass{article}
\usepackage{amsmath}
\begin{document}
\begin{equation}\begin{split}
\min z &= \mathrm{fa} \biggl(N_{\mathrm{h}} \mathrm{CFW} \sum_{j} Fw_j
+ \mathrm{CHU} \sum_{k} Q_k^{\mathrm{HU}}
+ \mathrm{CCU} \sum_{k} Q_k^{\mathrm{CU}}\biggr) \\
&\quad+ \alpha \sum_{j} \bigl(Qp_j + Qn_j\bigr)
\end{split}\end{equation}
\end{document}
If you must center the second row relative to the RHS of the first row, you could so via an array
environment embedded in the equation
environment.

\documentclass{article}
\usepackage{amsmath,array}
\begin{document}
The objective is to minimize the total operational cost:
\begin{equation}
\min z =
\begin{array}[t]{@{}>{\displaystyle}c@{}}
\mathrm{fa} \biggl(N_{\mathrm{h}} \mathrm{CFW} \sum_{j} Fw_j
+ \mathrm{CHU} \sum_{k} Q_k^{\mathrm{HU}}
+ \mathrm{CCU} \sum_{k} Q_k^{\mathrm{CU}}\biggr) \\
{}+ \alpha \sum_{j} \bigl(Qp_j + Qn_j\bigr) \\
\end{array}
\end{equation}
\end{document}
fa
a factor of the second part/line?