In solar applications, collectors are usually installed with a tilt angel to obtain the maximum amount of radiation. In this paper, the anisotropic model -Hay model was used to calculate the daily total radiation on the tilt face and theoretical analysis was used to get the optimum tilt angel of southern collector face in winter months. Then the diffused radiation on horizontal face was obtained by using the isolation between daily total radiation and daily diffused radiation. Computer program was written to calculate the month radiation under different tilt angel and the maximum angel corresponding to the maximum month radiation was found. At last, the two results were compared and analyzed.

Abstract. To pretend enterprises tamper data when environment protection administration check of law enforcement examination, in this study we structure a coal-fired power plant technology process model based on OPMSE by introducing Petri net concept. Through analog simulation, based on quantitative relation and law of conservation of mass to definite the actual inventory and discharge amount, we confirm whether the on-line monitoring data is true or not by comparing the simulating data with the available data.

A mathematical modeling method was devoted to study the thermal performance of integral solar air collector. A mathematical model of heat transfer was set up based on one-dimension assumptions at first, and then numerical solution was brought out by using finite-difference method under one-dimension steady heat exchange. Through the MATLAB programming, the approximate solutions for the local air temperature and thermal efficiency were obtained at the quasi-steady state. After calculation, the influence of air inlet velocity, inlet temperature, solar radiation intensity and height of flow channel on the performance of collector was analyzed. It is discovered that the mathematical model is reasonable, the thermal efficiency decreases with temperature of inlet air increasing and increases with air velocity increasing, on which the solar radiation intensity have little influence. Depth of the channel and optimum flow both have a best value.