Simulation Of Solar Energy Low Temperature Radiant Heating System

These days energy-consumption and environment protecting are two major problems that confuses people much. Finding new kinds of clean energy have been an important way to solve them. As a clean regenerative energy, solar energy is being widely applied in the field of HVAC. Due to the development of heat collecting technology and collection thermal efficiency, using solar energy as the actuation energy of refrigeration system becomes true. And more and more successful projects emerges, especially solar energy absorption chiller system projects of large or middle scales. However, the temperature of heat source of this kind of system can be proved higher(always over seventy-five degrees), which leads to larger squares needed if you want to get a higher heat source temperature. So, it comes to low temperature radiant heating system , which can be rightly combined with solar energy because of its low heat source temperature (always from thirty to sixty degrees) .Now many researchers focus on solar energy low temperature radiant heating systems. And most of their research follows this kind of thinking method: establishing two-dimensional partial equation of floor radiant heating system, then giving certain supposition conditions, and using finite difference methods to solve partial equation with programs. As the development of system simulation technology, there are more simulation tools which can provide many conveniences of system simulation for study, especially the authorized simulation software MATLAB/Simulink. This paper uses the new edition MATLAB7.1 to do some simulation research on of intensity of solar radiation, solar collector , water tank, and the whole system on the base of unstable conditions ; also, simulating on the surface temperature and heat flow flux of low temperature radiant heating system with stable conditions. The conclusions indicate that the amount of useful output energy of solar collector is largely determined by the intensity of solar radiation; with instable conditions, the outlet temperature has a similar changing trend of the inlet temperature of water tank, which is always lower by a range of zero degree to ten degrees; moreover, the surface temperature and heat flow flux of low temperature radiant heating system with stable conditions rise with the higher average temperature of the input and output water while fall with the further distance of heating tubes; finally , it is more time needed for the whole system operates stably if the outdoor temperature and the indoor heat load have the cosine changing rule ;and with the operating time flows, solar energy can meet the heating need of customers, which means it is not necessary to rely on the aid-heating energy.