**2. Heat transfer characteristics of single-phase flows**

As a representative case, coil of *PCD* = 200 mm and coil pitch of 30 mm is considered for discussion. Diameter of the pipe used in the coil is 20 mm. Boundary layer mesh was generated for the pipe fluid volume. Optimised grid after the grid independency studies was used in the analysis. Pressure velocity coupling was done using the SIMPLEC scheme. Momentum equations were discretised using QUICK scheme. Power Law scheme of discretisation is used for turbulent kinetic energy and dissipation rate equations. Convergence criterion used was 1.0e-5 for continuity, velocities, *k*, and *ε*. Temperature dependent properties as polynomial functions were used for water. For the energy equation third order QUICK discretisation scheme was employed. Convergence criterion for energy balance was 1.0e-07.
