Performance assessment of convective heat transfer in tubes with a temperature difference in the high‐temperature solar power generation system

Abstract

Heat transfer enhancement technology provides many advantages in heat exchanger applications. Thermal energy storage is a technology that stocks thermal energy by heating or cooling a storage medium so that the stored energy can be used later for heating and cooling applications and power generation. The experimental investigation was carried out for heat convection in tubes with significant temperature differences (400 and 600°C), which were used convective heat transfer in a tube with air-water steam and heat conduction oil in the high temperature solar thermal power generation system. From the experiment, the results recorded with an average maximum temperature for air, water, and steam up to 422.4, 413.9, and 405.7℃, respectively, with the outer wall temperature of 600℃. Similarly, for an external wall temperature of 400°C, the average maximum temperature was obtained up to 351.2, 310.9, and 308.1℃, respectively. Therefore, from the experimental results, when the diameter of the flow pipe is higher than that of pipe diameter, then the effect of flow velocity on heat flow temperature was uncertain. At last, from the results, we conducted that the empirical correlation of convective heat transfer in a tube with temperature difference exceeding 100℃ obtained. The results showed that the increase of temperature thermal energy storage system could effectively enhance heat transfer and the calculation results can be used to optimize the performance of the high-temperature thermal energy storage system. Novelty impact statement Assessment of convective heat transfer in tubes with a temperature difference in the high-temperature is performed. The increase of temperature in thermal energy storage system could effectively enhance heat transfer. Carried out the study for different temperature thermocouples tube bundles with Nu, Re, and Pr. Conducted the empirical correlation of convective heat transfer in a tube with temperature difference.