摘要
为了研究冰蓄冷空调用蓄冰材料的相变换热问题,本文利用FLUENT建立了蓄冷球的封闭空间二维模型,并考虑到了固相与液相的密度差的影响。通过对该球非固定融化过程的传热传质数值模拟,获得了球体内部温度场及液相体积比随时间变化的规律,讨论了不同传热温差和球径对蓄冷时间及蓄冷特性的影响。研究表明:在非固定融化过程中,由于固液的密度差,融化过程中固态物要上浮或下沉到封装器顶部或底部,从而与球壁产生接触融化,并且上浮的非固定融化时间比固定融化的要短;蓄冷球半径越大,相界面移动速度越慢,融化时间显著增加;载冷剂温度越低,相界面移动速度越快,融化时间越短。本研究为蓄冰系统的释冷过程及优化提供指导。
In order to research on heat transfer of ice storage materials in ice storage air conditioning, in this paper, a two dimensional closed space model of cold storage ball is established by using FLUENT, which takes into account the influence of solid and liquid phase density difference. Based on the numerical simulation of heat and mass transfer during the the process of ambulatory melting, the rule that the temperature and liquid volume ratio of the ball change with time are obtained, and the influence of different heat transfer temperature difference and ball diameter on the storage time and the cold storage characteristics is discussed. The research shows that during the process of ambulatory melting, because of the density difference between solid and liquid, solids must float or sink to the top or bottom of the packer during melting process, so as to contact and melt with the spherical wall, and the ambulatory melting time of floating is shorter than that of fixed melt; cold storage ball radius increasing and phase interface moving more slowly, significantly increased the melting time; refrigerant temperature islower, the phase interface moving faster, shorter melting time. This study provides guidance for the cooling process and optimization of ice storage system.
出处
《区域供热》
2018年第1期92-97,共6页
District Heating
关键词
冰蓄冷
相变融化
密度差
FLUENT
数值模拟
Ice storage
Ambulatory melting
The density difference
FLUENT
Numerical simulation
