空气加热器的论文 - 图文

毕业设计说明书(论文)

作 者： 学 号： 系： 能源与环境工程 专 业： 热能工程 题 目： 空气加热器的性能测试及研究

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2008年 6 月 20 日

毕业设计（论文）中文摘要

摘要 本文对一种空气加热器的性能进行了试验研究。对不同空气流速，加热功率下的工况进行了基本的研究。试验的结果表明：空气加热器加入多空介质后，空气侧的换热效率明显提高，但与此同时流动阻力也增加很快；流速的增加对换热效率的影响是最明显的，随着流速增加，每种工况下换热效率都提高很多；功率增加，提高了出口温度，但是并没有提高换热效率，热辐射引起的损失较大。对于流速较大的试验工况，试验达到稳定的时间较短。光管稳定时间与添加了多孔介质之后加热段的稳定时间相差较大，最大的可达30分钟左右。 对同一流速，随着温度的升高，压降升高，说明流动阻力增大。可能是在加热过程中，空气膨胀，使管中的气流增大，造成流动阻力的增大。在流速较小0.15m/s时通常只有20Pa左右的变化；而在流速较大0.25m/s时，压力的变化为60pa左右。虽然流速只相差0.1m/s。 由于本人能力、试验条件和时间的限制等多方面的原因，论文在很多方面存在不足，有待于更加深入的研究。 关键词 空气加热器 多孔介质 对流换热 温升速率 稳定时间 换热效率 04级本科毕业设计论文

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毕业设计（论文）外文摘要

Title THE PERFORMANCE TEST AND RESEARCH OF A AIR HEATER Abstract This article has conducted the experimental study to the performance of one air heater . We has conducted the basic research on the operating mode of the different velocity of flow, and thermal rating. The result of the test shows :When we put the cellular ceramics in to de air heater , thermal efficiency of the air side raise obviously, and flow resistance increase quickly too； The influence on changing thermal efficiency of increase of the velocity of flow is the most obvious, as the velocity of flow increases, thermal efficiency change and the heat transfer efficiency of each kind of operating mode improve much more ； The power increases, has improved temperature of exports , but has not improved the heat transfer efficiency , the losses caused in heat radiation are relatively great. As to the experimental operating mode of larger velocity of flow, steady time of the text is relatively short. The steady time of with the porous media is a large difference form the operating mode of without the porous media, the biggest one can be up to about 30 minutes. To the same velocity of flow, with the rising of temperature, press also rise, for flow resistance increase. It may be in the course of heating, the air swells , make the air current while managing increase, and cause flow resistance increase . Usually there are only about 20Pa of changes in the velocity of flow smaller 0.15m/s； In the velocity of flow bigger 0.25m/s, the change of the pressure, for about 60pa. Though the velocity of flow is only difference 0.1m/s. 04级本科毕业设计论文

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Because of my own ability、test conditions and time, and many other reasons , the paper has the insufficiency in many aspects , and it need to be more in-depth research. Keywords ： air heater ；cellular ceramics； convection heat transfer； speed of rising of temperature； steady time；heat transfer efficiency