不同加热方式对系统传热效率的影响

发布时间：2018-05-16 02:15

本文选题：自然对流 + 强制对流　；参考：《新疆大学》2017年硕士论文

【摘要】：埋沙治疗作为维吾尔医学传统疗法,在我国吐鲁番地区广为流传。然而,受到季节、地域、环境、时间等因素的影响,天然沙疗场所只能在每年的6~9月份进行,无法满足世界各地的患者随时随地接受治疗的需求。因此,建立一个不受自然气候影响的室内加热系统就十分重要。目前,室内加热系统都存在着加热效率低下,沙层垂直温度分布不均匀,加热中出现局部沙表温度过高,灼伤患者皮肤等问题。为了能够合理地解决这些问题,本文研究了六种不同的加热方式对沙层加热效率的影响,寻求一种能够提高沙层加热效率并使其垂直温度分布均匀化的最佳方案。首先,设计不同的加热系统实验方案,分别为自然对流-单向加热、自然对流-双向加热、自然对流-多向加热、强迫对流-单向加热、强迫对流-双向加热、强迫对流-多向加热。并根据方案对实验平台进行改造,完成多组实验,记录实验数据。其次,在数值模拟中,采用多孔介质导热方程、DO辐射模型以及标准k-?湍流模型,建立三维热物理模型,应用有限体积法计算加热系统中气固耦合问题。分别模拟不同的加热系统内温度场、速度场的分布情况,并与实验结果进行对比。最后,通过对比分析不同加热系统内的温度场、速度场分布,以及从加热效率、加热效果和加热过程中所消耗的能量三方面进行对比分析,确定出加热系统的最优方案是:自然对流-多向加热系统。该方案不仅能够提高加热效率,减少能源损耗,节约成本,而且加热效果良好、使得沙层垂直温度分布均匀化。
[Abstract]:As a traditional Uygur medicine therapy, sand burying therapy is widely spread in Turpan area of China. However, due to the influence of season, region, environment, time and other factors, natural sand therapy can only be conducted in June and September of each year, which can not meet the needs of patients all over the world to receive treatment anytime and anywhere. Therefore, it is very important to establish an indoor heating system independent of natural climate. At present, there are some problems in indoor heating system, such as low heating efficiency, uneven vertical temperature distribution in sand layer, excessive local sand surface temperature, skin burn and so on. In order to solve these problems reasonably, this paper studies the influence of six different heating modes on the heating efficiency of sand bed, and seeks the best scheme to improve the heating efficiency of sand layer and to homogenize its vertical temperature distribution. First of all, different experimental schemes of heating system are designed, which are natural convection-unidirectional heating, natural convection-bidirectional heating, natural convection-multi-directional heating, forced convection-unidirectional heating, forced convection-bidirectional heating. Forced convection-multidirectional heating. The experiment platform is reformed according to the scheme, and many groups of experiments are completed and the experimental data are recorded. Secondly, in the numerical simulation, the porous medium heat conduction equation is used to model the do radiation and the standard k-? A three-dimensional thermophysical model was established and the finite volume method was used to calculate the gas-solid coupling problem in the heating system. The distribution of temperature field and velocity field in different heating system were simulated and compared with the experimental results. Finally, the temperature field, velocity field distribution, heating efficiency, heating effect and energy consumption in different heating systems are compared and analyzed. The optimal scheme of heating system is: natural convection-multidirectional heating system. This scheme not only can improve heating efficiency, reduce energy loss and save cost, but also has good heating effect, which makes the vertical temperature distribution of sand layer more uniform.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R29

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