| With the increasing of energy consumption in building, it is important to reduce its proportion in the world’s total energy consumption. To solve the contradiction between energy and the environment the useful method is to develop renewable clean energy. Ningxia is located in the northwest of China and the rich solar energy resources gives it much advantages to development and utilize solar energy which is of great significance for reduction emissions targets.In this dissertation the heat utilization characteristics of solar hot water floor radiant heating/hot water system were studied with the method of comprehensive theoretical analysis, experiment and numerical simulation and the study mainly completed the following six tasks:(1) A solar floor radiation heating/hot water system was designed and set up. The main component of experiment system was determined with 8 m2 flat solar collector, 300 1 heat storage water tank, 71 m floor heating tube. The measured meteorological data in 2014 show out that the total amount of the solar day radiation during heating season are 1333.7 MJ/m2 and the total amount of solar day radiation during no heating season are 2695.4 MJ/m2. It also shows out that solar energy resources in Ningxia region are relatively abundant with longer sunshine time and it has a high potential of solar energy resources development and utilization.(2)Based on the calculation model of solar irradiance of standard sunny days outside the atmosphere, the calculating program of solar total radiation on the surface of horizontal plane and collector tilt plane is programed with VB programming software. The factors that influence the solar irradiation are analyzed with MATLAB simulation software and the installation angle of solar collector in Yinchuan Ningxia is optimized. Simulation results show that in the coldest January, the best solar collector installation Angle is of 64° and in the hot June, the best solar collector installation angle is of 2°.(3)Through the heat transfer process analysis of plate solar collector, the mathematical model of single flat solar collector was established. On the basis of the mathematical model of single solar collector, the thermal numerical simulation program of flat solar collector array is established. And the performance of thermal array with different series/parallel connection mode is analyzed. Besides that the factors affecting the thermal characteristics of the flat solar collector series such as solar irradiance, heating medium circulation velocity, outside environment temperature .etc are discussed.(4)Based on analysis of the heating transfer process of low temperature hot water floor radiant,its mathematical model is established. By using the mathematical model, the influence of the operation parameters (including water supply temperature, water circulation velocity), the floor structure parameters (including tube spacing, coating thickness, floor surface decoration material) on the floor surface temperature, indoor air temperature are discussed with computer simulation analysis.(5)With the above study the characteristics of the solar floor radiation heating system was tested.And the energy saving potential of solar energy floor radiation heating was calculated with the test data of the coldest season in the middle heating season. Results show that the solar floor radiation heating system has good performance in heat collection and store. The solar floor radiation heating system can greatly reduce the fluctuation range of indoor temperature, and the indoor average temperature can be maintained 12℃ higher than the outdoor average temperature.(6)The characteristics and operation mode of solar water system were discussed. The characteristics of heat store and emission of the heat storage water tank were investigated. Results show that the water temperature and water flow rate have an important impact on the running characteristics of heat storage water tank. The theoretical analysis shows that the heat storage efficiency may be promoted by increasing the total heat transfer coefficient and the heat transfer area. |
PDF Full Text Request