In order to increase the efficiency of solar collector, a methodology is proposed based on the analysis of its influencing factors, such as thermal conductivity of filled layer, structure forms of filled layer and hea...In order to increase the efficiency of solar collector, a methodology is proposed based on the analysis of its influencing factors, such as thermal conductivity of filled layer, structure forms of filled layer and heat loss coefficient. The results of analysis show that the heat transfer between pipes in evacuated tube is one of the most important factors, which can lead to the decrease of the outlet temperature of working fluid. In order to eliminate the negative influence of the heat transfer between pipes, the hollow filled-type evacuated tube with U-tube(HUFET) was developed, and the heat transfer characteristics of HUFET were analyzed by theoretical and experimental studies. The results show that the thermal resistances decrease with the increase of the thermal conductivity of filled layer. When the thermal conductivity is over 10 W/(m·K), the change of thermal resistances is very little.Furthermore, the larger the thermal conductivity of filled layer, the less the rate of the energy transfer between the two pipes to the total energy transfer, which is between the absorber tube and the working fluid. There is a little difference between the efficiencies of HUFET and UFET, with the efficiency of HUFET 2.4% higher than that of UFET. Meanwhile, the validation of the model developed was confirmed by the experiment.展开更多
Under the new situation, news and propaganda work must hold high the banner around the overall situation, serve the people, make reform and innovation, adhere to the correct guidance of public opinion, to improve the ...Under the new situation, news and propaganda work must hold high the banner around the overall situation, serve the people, make reform and innovation, adhere to the correct guidance of public opinion, to improve the ability to guide public opinion, to create a good public opinion environment, to better play and publicize the party＇ s ideas, to promote social justice, to access to social conditions public opinion, to guide social hot spots, to divert the public mood, to improve the important role of public opinion. We should put the improvement of the ability to guide public opinion in a prominent position, conduct in-depth research, and come up with concrete measures to achieve new results. We must adhere to the Party＇ s principles; firmly grasp the correct guidance of public opinion. Guiding correctly public opinion will benefit the country, party and people; guiding media wrong will make damage to China, party and people. To firmly establish political awareness, the overall sense of responsibility, position sense, we should put adhering to the correct orientation in the first place on the news and propaganda work.展开更多
基金Projects(2011BAJ03B12-3,2013BAJ10B02-03) supported by the National Science and Technology Program during the 12th Five-year Plan Period,ChinaProject(51378005) supported by the National Natural Science Foundation,China+1 种基金Projects(DUT14RC(3)123,DUT14RC(3)129) supported by Fundamental Research Funds for the Dalian University of Tecnology,ChinaProject(DUT14ZD210) supported by the Fundamental Research Funds for the Central Universities of China
文摘In order to increase the efficiency of solar collector, a methodology is proposed based on the analysis of its influencing factors, such as thermal conductivity of filled layer, structure forms of filled layer and heat loss coefficient. The results of analysis show that the heat transfer between pipes in evacuated tube is one of the most important factors, which can lead to the decrease of the outlet temperature of working fluid. In order to eliminate the negative influence of the heat transfer between pipes, the hollow filled-type evacuated tube with U-tube(HUFET) was developed, and the heat transfer characteristics of HUFET were analyzed by theoretical and experimental studies. The results show that the thermal resistances decrease with the increase of the thermal conductivity of filled layer. When the thermal conductivity is over 10 W/(m·K), the change of thermal resistances is very little.Furthermore, the larger the thermal conductivity of filled layer, the less the rate of the energy transfer between the two pipes to the total energy transfer, which is between the absorber tube and the working fluid. There is a little difference between the efficiencies of HUFET and UFET, with the efficiency of HUFET 2.4% higher than that of UFET. Meanwhile, the validation of the model developed was confirmed by the experiment.
文摘Under the new situation, news and propaganda work must hold high the banner around the overall situation, serve the people, make reform and innovation, adhere to the correct guidance of public opinion, to improve the ability to guide public opinion, to create a good public opinion environment, to better play and publicize the party＇ s ideas, to promote social justice, to access to social conditions public opinion, to guide social hot spots, to divert the public mood, to improve the important role of public opinion. We should put the improvement of the ability to guide public opinion in a prominent position, conduct in-depth research, and come up with concrete measures to achieve new results. We must adhere to the Party＇ s principles; firmly grasp the correct guidance of public opinion. Guiding correctly public opinion will benefit the country, party and people; guiding media wrong will make damage to China, party and people. To firmly establish political awareness, the overall sense of responsibility, position sense, we should put adhering to the correct orientation in the first place on the news and propaganda work.
