Study On Key Problems Of Building-Integrated Solar Hot Water System

Building is a good platform to make full use of solar energy. It is of importance for sustainable energy supply of our country to use renewable energy like solar radiation by means of building integrated components. Solar hot water system can be used to supply domestic hot water, which can significantly save money spent on different fuels. Building-integrated solar hot water system (SHW) is one of the main methods for low-cost and large scale application of solar energy. In this paper, a method based on cost and benefit evaluation is applied to account for the technology-economic analysis of both the concentrated and concentrated-individual solar hot water systems using electric, city gas and heat pump as auxiliary heating device respectively. An example of a 36-user residential building in Shanghai is chosen for analysis. Furthermore, a standard on how charging hot water supplied by SHW is proposed. And in respect for concentrated and concentrated-individual SHW systems, the standard is used to calculate the yearly solar hot water fee of a practical SHW system respectively using electric, city gas and heat pump as auxiliary heating device. It is proved that cost-benefit evaluation method & the hot-water-charging standard are valuable for evaluating and charging DSHW systems in practice. Also performed is the experimental analysis of thermal stratification in a solar heat storage tank, especially the impact of temperature stratification on the off letting hot water load.