# Condenser Design for On-Board ORC Recovery System
## 5 Design Results  
The system geometry has been defined respecting the required constraints. A square configuration of the condenser has been chosen. The previous Figure 3 represents the simulated condenser. Streams numbers 1 and 2 are the inlet and outlet of the working fluid, and streams 4 and 5 are the inlet and outlet of the cooling fluid. Stream 3 is the refill of the fluid; in this case, it is not considered, but it is important to mention the fact that this opportunity exists. Table 2 reports the operating specifications of the main streams. After numerous iterations, the optimal solution has been found. The considered configuration is a compromise between a reasonable pressure drop and the smallest area. All data and a representation of the condenser are, respectively, reported in Table 3 and Figure 6. \begin{table}
\begin{tabular}{c c c} \hline \hline  & **Stream n\({}^{\circ}\) 1** & \\ \hline
**Temperature (K)** & & 371 \\
**Pressure (kPa)** & & 610 \\ \hline  & **Stream n\({}^{\circ}\) 2** & \\ \hline
**Temperature (K)** & & 342 \\
**Pressure (kPa)** & & 606 \\ \hline  & **Stream n\({}^{\circ}\) 3** & \\ \hline
**Temperature (K)** & & 313 \\
**Pressure (kPa)** & & 101.3 \\ \hline  & **Stream n\({}^{\circ}\) 4** & \\ \hline
**Temperature (K)** & & 334.3 \\
**Pressure (kPa)** & & 100.3 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Condenser Streams. \begin{table}
\begin{tabular}{c c} \hline \hline \(\mathbf{L_{1}}\) **(m)** & 0.3 \\ \hline
**L\({}_{2}\) **(m)** & 0.3 \\ \hline
**L\({}_{3}\) **(m)** & 0.2 \\ \hline
**d\({}_{1}\) **(m)** & 0.008 \\ \hline
**d\({}_{r}\) **(m)** & 0.01 \\ \hline
**d\({}_{f}\) **(m)** & 0.016 \\ \hline
**P\({}_{1}\) **(m)** & 0.017 \\ \hline
**S (m)** & 0.002 \\ \hline
**t\({}_{f}\) **(m)** & 0.0003 \\ \hline
**N\({}_{r}\)** & 17 \\ \hline
**N\({}_{s}\)** & 15 \\ \hline
**N\({}_{tot}\)** & 17 \(\times\) 15 = 255 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The condenser’s main dimensions. Figure 6: The condenser’s chosen configuration. (**a**) actual disposition in the condenser assembling, (**b**) triangular configuration characteristics, (**c**) finned pipe representation. Finally, Table 4 shows the operating conditions of the two fluids, R245 fa and condensation water, in all its constituent parts (de-superheated, condensation, and sub-cooling). The simulation program also makes it possible to graphically show (Figure 7) the heat exchanged in each considered section. Once these quantities are known, it is possible to obtain the actual heat exchange surface in the various parts (Table 5) using the above procedure. \begin{table}
\begin{tabular}{c c c} \hline \hline  & **R245 fa** & \\ \hline  & **Inlet** & **Outlet** \\ \hline
**Mass flow rate (kg/s)** & 0.5 & 0.5 \\
**Temperature (K)** & 371.4 & 341 \\
**Pressure (kPa)** & 615 & 610 \\
**Enthalpy** & 60.3 & 32.5 \\
**Density** & 31.33 & 32.78 \\
**Steam quality** & 1 & 1 \\ \hline  & **Water** & \\ \hline  & **Inlet** & **Outlet** \\ \hline
**Mass flow rate (kg/s)** & 1 & 1 \\
**Temperature (K)** & 313 & 334.3 \\
**Pressure (kPa)** & 101 & 100.97 \\
**Enthalpy** & \(-\)2409.21 & \(-\)2403.55 \\
**Density** & 828.07 & 828.07 \\
**Steam quality** & 1 & 1 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Fluid specifications. Figure 7: Thermal configuration and thermal exchange in the condenser. Finally, in order to evaluate the average effectiveness value, it is possible to weigh the effectiveness with the corresponding area. The procedure is the same as the one followed for the overall heat transfer coefficient.