食用油罐内冷媒管降温模拟试验与优化

Simulated experiment and optimization of cooling of refrigerant pipe in edible oil storage tank

为缓解食用油在储藏过程中出现的热分层现象,设计内置冷媒管的食用油储罐,并通过调整冷媒流动方式、冷媒流量和冷媒温度等对储油进行降温对比试验。结果表明:采用上供式和下供式降温均可在储油温度整体下降的同时有效缩小上下层温差(1.93、3.67℃),且与自然降温(6.79℃)相比,热分层现象得到明显改善。采用下供式降温的效率最高,较上供式提高了约20%,且下层油温较上供式低约1.9℃。基于Ansys(Fluent)商用计算流体动力学软件平台,通过数值模拟进一步研究了采用下供式的冷媒流量对下层油温的影响。结果显示下供式降温可有效阻隔外部传热,而下层温度变化集中在低温区域,对远离入口侧区域的影响并不明显。

In order to alleviate the thermal stratification phenomenon of edible oil during storage,the edible oil storage tank with built-in refrigerant pipe was designed,and the cooling contrast test of the stored oil was carried out by adjusting the refrigerant flow mode,refrigerant flow and refrigerant temperature.The results showed that both up-supply and down-supply cooling could effectively reduce the temperature difference between upper and lower layers(1.93,3.67℃)when the oil storage temperature decreased as a whole,and the thermal stratification phenomenon was significantly improved compared with the natural cooling(6.79℃).The maximum cooling efficiency of the down-supply was about 20%higher than that of up-supply,and the lower layer oil temperature was about 1.9℃lower than that of up-supply.Based on the commercial computational fluid dynamics software platform of Ansys(Fluent),when down-supply was adopted,the effect of refrigerant flow on the lower layer oil temperature was further studied through numerical simulation.The results showed that the down-supply could effectively block the external heat transfer,while the lower layer temperature changes were concentrated in the low temperature area,and the effect on the area far from the inlet side was not obvious.