The Study Of Solar Energy Heating System Simulation

Serious environmental pollution is caused by over-exploitation of energy in developing countries.As a clean and pollution-free kind of energy, solar energy is widely applied in the field of electricity generation and heating. A novel program of direct solar energy radiant heating system is presented in this paper. The program has two sub-systems which heat for rooms daytime and nighttime respectively. The factors of solar energy heating system were studied by dynamical simulation on the operation of this program.Then the solar energy heating-pump system was simulated analytically, and the two systems were compared with each other, which had directive significance to the study.The main contents and results in this paper are as follows:(1)The study of simulation of direct solar heating system is performed and the mathematical model of solar irradiance, solar collector, tank and radiant panel are established by the research on direct heating system.Heating systems which worked daytime and nighttime were simulated dynamically respectively by the software called Visual Basic.The effect of the area of collectors on solar heating system is studied. The required area of collectors is varied with the load of heat monthly. The simulation on the two sub-systems shows that the heating-supply in Nov. and Mar. could be satisfied using bigger area of collectors all the day in this program,but 59% of the supply could just be satisfied daytime and 41% be satisfied nighttime in cold Jan, and great change exists in temperature of the surface of floor. The effect of the volume of the storage tank and the flow of collector tubes on the systems are also simulated. The solar guarantee rate called f reached its maximum value when the ratio called L/(Ac) between the volume of the tank and the area of heating system which worked nighttime was 40L/m2.The solar guarantee rate increased while the flow of inlet tube did, but the rate no longer increased when the flow was 0.8kg/s.(2) The operation on conditions of solar heating system was simulated through the investigation on indirect solar heating system.The static simulation on heat-pump by means of the Software Aspen concluded that the higher the temperature of the storage tank had, the higher the power of the compressor did. The dynamical simulation on indirect heating system showed COP of the system is 2.6 while Ac was 50 m2 and L/(Ac) was 100 L/m3,which could fully satisfy the heat load of rooms in Jan. And the heat-supply of indirect system was much more stable than that of direct system.Larger size of collectors was required in direct solar heating systems for the night, but in cold months auxiliary heating was also needed to provide extra heat.Therefore, the direct system was more suitable for buildings, such as teaching buildings, office buildings used primarily during the daytime.Although the indirect system was used to offer heat for building all-day beacause of its stable heating, the initial investment is high and plenty of power was required in running. The direct system could be coupled with the indirect system, the former was used to offer and store heat for day, the latter was used to offer in night.The size of collectors and the investment might be reduced greatly beacause the temperature of the tank was not required too high due to heating-supply from heat-pump in the night.