Convectional heat transfer of TBAB clathrate hydrate slurry flow in copper tube
Convectional heat transfer of TBAB clathrate hydrate slurry flow in copper tube
复制标题
DOI：
--
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Fan Shuanshi
中科院分区：
文献类型：
--
作者：
Fan Shuanshi
四正丁基溴化铵（TBAB）溶液在0 ~ 12℃的温度范围内冷却后形成笼形水合物浆料（CHS）。这与普通空调运行的温度范围很好地兼容。因此，它被认为是一种理想的传热和冷藏介质。由于相变，在相同温差下，TBAB浆体的冷加载密度远高于水。此外，TBAB浆体具有流体性质，因此易于通过管道输送。因此，TBAB浆料以其节能优势在空调或区域供冷系统中具有很大的应用前景。本文研究了TBAB浆料在水平铜管中的传热特性。对不同雷诺数和恒热流密度下的对流换热系数进行了测量和分析。研究发现，固体颗粒的扰动和表观粘度的降低都可以破坏或变薄浆体流动的动量边界层，从而获得更好的换热系数。固相体积分数（Φ）对努塞尔数的影响不大，而雷诺数的变化对努塞尔数的影响不大。与文献比较表明，CHS测量的Nusselt数始终高于冰浆，甚至高于单相水。给出了努塞尔数与雷诺数的关系。
Tetra-n-butyl-ammonium bromide(TBAB)solution turns into clathrate hydrate slurry(CHS)when it is chilled in the temperature range of 0—12℃.This is well compatible with the temperature range of common air-conditioning operation.Thus,it is considered as an ideal heat-transport and cold-storage medium.Due to the phase change,TBAB slurry has far higher cold-loading density than water under the same temperature difference.Moreover,TBAB slurry behaves as fluid,so it can be easily transported through pipeline.Therefore,it is very promising to use TBAB slurry in air conditioning or district cooling system for its energy-saving advantages.In this paper,the heat transfer characteristics of TBAB slurry were investigated in a horizontal copper tube.The convectional heat transfer coefficients were measured and analyzed at different Reynolds numbers and constant heat flux.It was found that both the perturbation of solid particles and the decrease of apparent viscosity could destroy or thin the momentum boundary layer of slurry flow,which consequently contributed to a better heat transfer coefficient.The influence of volume fraction of solid phase(Φ)on Nusselt number seemed slight in spite of the change of Reynolds number.The comparison with references showed that the Nusselt numbers measured in CHS were consistently higher than those of the ice slurry and even single phase water.A correlation of Nusselt number with Reynolds number was presented.