A Hybrid Heating System Based On Solar Energy And Off-peak Electricity

Energy is one of the most serious problems shortage which the world and Chinese socio-economic development facing. The situation of the earth in which the humankind lives is deteriorated increasingly with the increase of the energy consumption that results from population rising and economy development. Energy saving and low energy application are the key ways to solve this problem. phase change thermal energy storage can storage energy by change the phases of phase change materials, which can be used to solve the nonconformity problem on supply and demand time of solar energy and building load. At the same time, it can be used in shifting the peak heating and cooling loads off-peak hours.A hybrid heating system is proposed, which consists of solar absorber, thermal energy storage and electrical heater. The phase change heat storage unit in the system can reserve the energy from both solar energy and off-peak electricity. It has relatively simple structure, a cylindrical shell covering a set of helical coil pipe. The shell is filled with paraffin as phase change material and the helical coil pipe is filled with water to conduct the heat exchange. The heat source for heating system is consisted of three parts: solar collector, electric heater, phase change heat storage. The daily heat load and hourly heating load of building of Qingdao in heating season is conducted with the usage of DeST-H energy consumption simulation software. The typical day hourly value of solar radiation of Qingdao is calculated based on the solar radiation law. In order to match the building heat load, an optimal operating mode is suggested considering the curve of time-sharing price and solar energy. The experiment results show a low energy consumption and good economic property comparing to that of the traditional heating system.Through analyzing heating load demand, solar energy collection and thermal storage performance of phase change thermal storage, the advantage of the hybrid heating system based on solar energy and off-peak electricity in energy saving and circumstance protecting is obvious. The related research will offer some useful references and be of benefit to popularize low energy application by system feasibility study. The conclusion of this thesis could provide reference for practical design work and operation management of the hybrid heating system based on solar energy and off-peak electricity.