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通过对冷凝式燃气热水器进行理论和试验研究 ,证明冷凝式燃气热水器节能效果显著 ,与普通燃气热水器相比较可节能 15 %左右。普通型燃气热水器排烟温度高 ,只能利用燃气的显热 ;冷凝式燃气热水器排烟温度很低 ,不仅能够充分吸收烟气的显热而且还能吸收潜热 ,使天然气的化学热得以充分利用。当排烟温度控制在40℃ ,过剩空气系数为 1.4时 ,冷凝式燃气热水器的热效率高达 98% ,比普通型燃气热水器的热效率提高近 13%。冷凝式燃气热水器几乎能够利用除散热损失以外的全部显热和 5 0 %以上的烟气潜热。按全国 3 5 0 0万燃气热水器用户平均每户每天耗热 30MJ计算 ,全国每年燃气热水器耗热 3 832× 10 8MJ,折合天然气约 10 6× 10 8m3。冷凝式燃气热水器的普及率如能达到 10 % ,按节气率 15 %计 ,全年就可节省能耗约 5 7× 10 8MJ,折合天然气约 1.5 9×10 8m3,节约的天然气可新增燃气热水器用户 5 2 .5万户。

Research on Condensing Type Gas Water-heater

??Through the theoretical and experimental research on condensing type gas water-heater,it is proved that its energy saving effectiveness is obvious an it can save energy by about 15% as compared with the general gas water-heater.The exhausted fume temperature of the general gas water-heater is high,only the sensible heat of the fume can be utilized;however,that of the condensing type gas water-heater is very low,not only the sensible heat can be fully absorbed but also the latent heat can be absorbed,which causes the combination heat of natural gas to be fully utilized.When the exhausted fume temperature is controlled at 40?? and the excess air coefficient is 1.4,the thermal efficiency of the condensing type gas water-heater may be as high as 98%,which is near 13% higher than that of the general gas water-heater.The condensing type gas water-heater can almost utilize all the sensible heat except the loss of heat sinking and over 50% of the latent heat.If there are 35×10⁶ users of gas water-heater in the whole country at present and the heat consumption of each user is 30 MJ/d,the total heat consumption of the gas water-heaters in the whole country is 383.2×10⁹ MJ/a,in which the converted matural gas is 10.6×10⁹m³/a;and if the popularization ratio of the condensing type gas water-heater is 10% and its gas saving ratio is 15%,the energy consumption of about 5.7×10⁹MJ/a may be saved,in which the converted natural gas is 159×10⁶m³/a,and the saved natural gas may meet the needs for increasing 525×10³ new users of gas water-heater.