Paper Title
Investigation of the Fluid Flow Rates Effect on the Characteristics and Performance of Evacuated Tube Solar Collector in a Parallel-Series Arrangement

Abstract
The solar collector's performance depends on the number of solar collectors and the configuration of the circuit. When the area used is large, more solar collectors are needed. The parallel-series series configuration is used to obtain the desired hot water temperature. Besides, external factors are considered: the environment's temperature, solar radiation, and flow rate distribution. Ambient temperature and solar radiation are factors that cannot be regulated because they depend on the weather. The flow rate is an external factor that we can adjust. This research uses MATLAB software to conduct simulations.The collector circuit in this study is a new series from previous research. Variations of fluid flow rates are tested with different solar radiation. The flow rate variations are 1,6 - 4,72 kg/s. Based on the simulation, changes in the fluid flow rate (mass flow rate) can affect the performance and characteristic of the collector.The higher the mass flow rate, the smaller the resulting outlet temperature will be. The higher the mass flow rate, the higher the efficiency.Inthe end, determining the right mass flow rate can be adjusted according to the needs. Keywords - Solar Collector, Flow Rates, Performance, Parallel-Series.