Numerical simulation of the special shaped cavity receiver heat loss laws in a elevation angle cycle

Based on the influence of temperature on the physical properties of the gas(air)in the thermal insulation layer of the receiver,the HOTTEL model and the three dimensional numerical simulation method,the change of heat loss of the heat receiver under natural convection in a region with a high angular cycle was studied,The relationship between The relationship between the absorber internal temperature field,N_(uc),Nur in the absorber and the proportion of the heat loss were obtained. the result shows that:In a highly angular cycle,convective heat loss decreases first and then increases,the change of the radiation heat loss and heat conduction loss are small and the elevation angle has a great influence on N_(uc),when the elevation angle becomes larger,the N_(uc)decrease first then increase,but,the effect of elevation angle on Nu is small and which changes only in a very small range of fluctuations;In three kinds of heat loss,convective heat loss is the largest proportion,the second is the radiation heat loss and the heat loss is the least.