| Take a28.08m2laboratory as the research object. A radiate wall system is designedin this paper according to the floor radiant heating system and the ceiling radiantcooling system. Heat supplied in winter is76-80W/m2, which is more than the designheat load index and thus the requirement of heating can be satisfied. However coolingcapacities in summer is about37W/m2, which is51%of the design cooling load index.Therefore a displacement ventilation system is needed.Based on the design scheme, a radiant wall system is built. Test results show thatthe supply water temperature is55℃. Even though the temperature of water tank drops10-15℃in a hour, there is a temperature rise of3℃in room. After2hours operation,temperature of room will be increased from8-10℃to16℃. If the temperature ofwater tank can be stable, the heating result will be better.Select three flow rates in pipe to experiment. Analysis shows that it is reasonableto set the flow rate of the radiant wall system as1m/s. After24-36hours operation,the temperature of water tank stabilized at37℃. The average surface temperature of thewall is around27.8℃. The vertical temperature gradient is less than-0.8℃/m. Thecomprehensive heat transfer of the wall is about90W/m2, whose deviation is less than15%compared to theoretic calculation. So the requirement of heating can be satisfied.Based on the small radiate wall system, three heat device solutions are proposedand analyzed in economy. Solution1with air source heater is an ideal choice. Theannual cost is3823.67yuan/a, which is lowest. And environmental benefit can be gainedfor less pollution. |
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