Study On Radiative Properties Of Open-cell Porous Ceramics And Design Of Solar Air Receiver

A typical CSP plant consists of three main subsystems: solar collector field,solar receiver and power conversion system.The solar receiver is the place where work fluid is heated by solar radiation,so the efficiency of the solar receiver directly affect the generation efficiency of CSP plant.Compared with tube receivers,volumetric receivers with a ceramic absorber are simpler,cheaper and more effectively.Therefore,in order to optimize the thermal efficiency of a volumetric receiver and improve its design,a thorough study of the radiative characteristics of porous ceramics is an important first step.In this paper,the structure parameters of foam ceramics were analyzed with the help of the combination of tomography and granular analysis.Spectral measurements(FTIR)and tomographic image analysis method was applied to acquire the Rosselend extinction coefficient of ceramic samples with different porosities and cell densities.The results showed that the radiative properties of porous ceramic are strongly dependent on its microstructure parameters,while the type of material has little influence.The Rosseland extinction coefficient increased with increasing cell density and decreasing porosity.The results of the two methods are compared and analyzed.Based on the experimental results,two empirical correlations related to the window diameter and porosity were proposed to predict the Rosseland extinction coefficient of open-cell porous ceramics.Based on these empirical correlations,a one dimensional model is established to calculate the temperature distribution inside the receiver under different conditions which include porosity,pore size,air flow rate,input radiation intensity,air inlet temperature,etc.The results reply that above-mentioned factors have a significant impact on the performance of receiver.which provide a reference to analyze the receiver thermal performance...