陶瓷填充床内H型翅片管换热特性实验研究

Experimental study on heat transfer characteristics of H-type finned tube in ceramic packed bed

基于热逆流氧化床内置翅片换热器的取热过程,自行搭建陶瓷填充床内置翅片换热器稳态取热实验台,实验研究陶瓷多孔介质围成的狭小空间内H型翅片管的换热特性,并通过外壁镀银的方法分析传热方式对H型翅片管换热系数的贡献。结果表明:H型翅片管边缘的温度随入口温度增加最大增长264℃,随入口雷诺数增加最大仅增长35℃,且靠近基管管壁处温度随入口温度和入口雷诺数变化不大;蜂窝陶瓷的存在强化了H型翅片管外壁面的热辐射作用,同时减小了29. 80%的散热量,但在一定程度上抑制对流传热;辐射传热贡献度随入口温度增加从48. 17%增至60. 34%,随入口雷诺数增加从57. 2%降至55. 35%。对试验数据进行归纳分析,得到陶瓷氧化床内H型翅片管换热特性的试验关联式。

Based on the heat extraction process of coal mine VAM thermal oxidation with embedded finned heat exchanger,the steady state heat extraction experimental platform was built.Heat transfer characteristics of H-type finned tube in a narrow space enclosed by ceramic porous medium and the contribution of heat transfer mode to the heat transfer coefficient of H-type finned tube by the method of plating silver on the outer surface were studied experimentally.The maximum temperature on the edge of the H-type finned tube increased 264 degree centigrade with the increase of the inlet temperature,and changed only 35 degree centigrade with the increase of the Reynolds number.The temperature of the tube wall of the base tube changed little with the increase of the inlet temperature and the Reynolds number.Honeycomb ceramic could strengthen the heat radiation of H-type finned tube and the heat loss was reduced by 29.8%,but inhibit the convection heat transfer to a certain extent.The radiation heat transfer contribution degree increased from 48.17%to 60.34%with the increase of inlet temperature and reduced from 57.2%to 55.35%with the increase of Re.The experimental data were inductively analyzed,leading to an experimental correlation of heat transfer characteristics of H-type finned tube in the ceramic oxidation bed.