Analysis of heat and fluid transport of industrial boilers

Nowadays, industrial boilers are used in a wide range of areas to meet the need for hot water. Different types of equipment, which act as tanks and heaters in the system, are involved in heating the cold water. Heat transfer is carried out by serpentine which is one of these equipments. In this study, the thermal performance of serpentines with different helical tube geometries was numerically analyzed. Serpentine geometries have 0°, 10° and 15° conical angle designs. Serpentine pipe lengths are approximately 5.3 meters and the tank volume is 100 liters. Water was chosen as the working fluid. The mass flow rate in the serpentine is 0.101 kg/s and the inlet temperature is 363 K. The laminar flow was occured in tank side and the Rayleigh number varies between 4x107 and 1,2x108. In the numerical solution, the desired temperature for the domestic water was determined as 50°C. In the numerical solution, the cold fluid (domestic water) was heated to the desired temperature and discharged after the cold fluid reached to the desired temperature. According to the numerical analysis results, it has been determined that the 10° conical coil has higher heat transfer in the heating condition and the 15° conical coil has higher heat transfer in the usage state. The time for the domestic water to reach 50°C is 1200 s., 420 s. and 478 s. for 0°, 10° and 15° coils, respectively. In addition, the numerical model was validated with experimental data.