| As a solution to the world energy crisis, tower solar power technology has become apopular topic to researchers and policy makers, while solar power plants was built everywherein recent year. It is a common sense that those who can know well about the technology willobtain more future energy. ETR (External Tubular Receiver) using molten salt as HTF(HeatTransfer Fluid) is widely used in solar plant and has a relatively simple structure. Based on thecharacteristics of the CSP (Concentrating Solar Power), a mathematical model of ETR wasdeveloped to analyze the performance of the whole system, and was simplified in a reasonableway. We discussed the solution to the model when the flow state is laminar and boundaryconditions when there is turbulent flow inside the receiver, proposed a method to simplify heatflux distribution.As there are numerous pipes in this kind of receiver, direct numerical simulation pose ahuge challenge. In order to reflect the physics phenomenon inside pipe receiver and lower thecalculating difficulty, with Fluent we simulated the flow and heat transfer of a20-pipe-consisted receiver and single pipe, analyzed the feature of the flow and heat transfer,and investigated different kind of parameters’ effects on the heat transfer efficiency.With simplified single-pipe-model and boundary conditions, a theoretical model wasdeveloped to determine the temperature rise and efficiency of the receiver. As some classicalequations were used in the model to calculate convection heat transfer coefficients, thus resultsof each of them was compared with numerical solutions. We also obtained equations whichcould precisely calculate the temperature rise and heat efficiency of the molten salt when itpassed through the receiver, studied the accuracy of the equations among different conditions,and proposed a method to correct it with a series of factors. In the end, an engineering examplewas used to show how we can use it. |
