射流泵平板速冻过程数值模拟与实验研究

Numerical simulation and experimental study on rapid freezing process of ejector plate

为了验证射流泵供液平板速冻机的节能效果,利用Fluent 6.3.26和Gambit 2.4.6(CFD)软件对水在射流泵供液平板速冻机中冻结过程进行了数值模拟,对水的物性参数进行分段线性处理,选取第1层、第6层和第11层蒸发平板几何中心处托盘,分别进行了模拟与实验数据的对比。结果显示,三层托盘中水的冻结时间模拟值与实验值相对误差绝对值分别为0.7%、1.4%、1.3%,冻结过程的温度模拟值与实验值的最大相对误差绝对值分别为5.6%、4.2%、5.6%,模拟结果与实验吻合较好。此外,对射流泵平板速冻机的节能特性进行了试验研究,结果表明,与传统的热力膨胀阀供液相比,射流泵供液节能达9%,冻结时间减少14%,同一层平板不同托盘的温度不均匀性仅为3.6℃,底层托盘的冻结速度快于上层,射流泵适用于平板速冻机。

In order to verify the energy-saving effect of the ejector’s liquid feeding plate freezers,the freezing process of water in the ejector’s liquid feeding plate freezer was numerically simulated by Fluent 6.3.26 and Gambit 2.4.6(CFD) software,and the physical parameters of the frozen product were processed in a piecewise linear manner.The trays at the geometric center of the first,sixth and eleventh evaporation plates were selected,and the simulation and experimental data were compared respectively.The results show that the simulated value of the freezing time of the water in the three-layer pallet is opposite to the experimental value.The absolute values of the errors are 0.7%,1.4%,and 1.3%,respectively.The absolute relative error values of the simulated and frozen values of the freezing process are 5.6%,4.2%,and 5.6%,respectively.The simulation results agree well with the experimental results.The energy-saving characteristics of the ejector flat-frozen freezer were tested.The results show that compared with the traditional thermal expansion valve,the jet pump can save 9% energy,the freezing time is reduced by 14%,and the temperature of different trays of the same layer is different.The unevenness is only 3.6 ℃,the bottom tray is frozen faster than the upper layer,and the jet pump is suitable for the flat freezer.