| The energy consumption of buildings, being consist of an important part of the world’s energy consumption, is able to solve the hot water consumption in the buildings, has great practical significance in alleviating the energy crisis. Shenzhen has rich solar energy resources and policies to promote the use of solar thermal, In the production of hot water, using SWHS to replace the traditional source of heat has huge energy conservation and environmental protection significance.First of all, in this paper, beginning from the method of solar radiation intensity calculation, and with vertical all-glass vacuum solar collectors as the research object, analyses the heat transfer process between the heat-absorbing pipe, the cover glass, the environment and the fluid medium, combining with the characteristics of all-glass vacuum tube;we build thermal resistance network diagram based on the calculation model both at home and abroad. Through the method of hypothesis, we look for the calculation method of solar collector heat gain under the condition of outlet temperature unknown, using MATLAB software to program.Then, the paper calculates the outlet temperature of the thermal collectors and the collector heat gain under different conditions, also analyzes the influence of installation angle, solar intensity, and length of pipe on the heat gain, the outlet temperature, and the convective heat transfer thermal resistance. The results show: the greater the inclination angle, the lower outlet temperature is, the variation of inclination angle has certain influence to heat gain; with the increase of the solar radiation, the outlet temperature and heat gain are increased significantly; convection heat transfer resistance in the pipe plays a decisive role in the heat gain, the change of inclination angle has great effect on the convective heat transfer thermal resistance, and the solar radiation has little effect on the thermal resistance. The computed result recommends all-glass vacuum tube manufacturer length according to the result is around 1.80 m,but collector installation angle is not more than 30 °.Furthermore, combing with the actual characteristics of water in a 20-story student apartments in every month, according to design specifications, this paper completes the calculation of design of the SWHS in student apartment, the equipment selection, the equipment layout and system principle diagram. The paper calculates the solar heat gain of solar hot unit under different angles, and analyze the use hot water load of student apartment combining their actual water consumption condition, combing the change of the male and female apartment monthly hot water using load, we determine when the collector installation angle is 13 °, the 20 th floor student apartments solar unit obtains a biggest year heat gain,at the same time, male and female apartment solar fraction are 0.25, 0.3 respectively. Then, by analyzing the relationship between the number of floors and solar fraction, determine that the value of the solar fraction is inversely proportion to number of floors, has nothing to do with the single building area.Finally, The paper proceed the energy conservation benefit analysis of the SHWS,The system saves 601 million yuan, reduces carbon dioxide emissions 6921.4t in the life cycle, the record shows that the energy saving effect is very good. |
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