Simulation and verification for temperature distribution of cooling storage process of chilled water storage tank

摘要

Chilled water storage technology has been widely used in air conditioning system.During cold storage and release process, a interlayer exists in the cooling storage tank which has large temperature gradient, called metalimnion.The formation and stability of metalimnion has a great influence on the effect of cold storage and the thickness of metalimnion is directly affect the cooling storage quantity and storage efficiency of storage tank.In the process of cold storage, the low temperature water evenly into the cooling storage tank from below, at the meantime, the high temperature water flows out from the top of the tank.Water flow along the axial of the cooling storage tank.Due to the shape of the cooling storage tank has great influence on metalimnion.The study establishe the model of cooling storage tank, using GAMBIT software build grid and set about 160000 grid.The study also simulate the cooling storage process for five different height diameter ratio of storage tank by CFD(FLUNET software), whose size are 1100m3 and height diameter ratio is 0.68, 0.98, 1.28, 1.58 and 1.88 respectively, getting the temperature distribution for metalimnion of evew working condition and the change rule of metalimnion.The results prove that there has been a metalimnion in cooling storage during the cooling storage process and the change rate of its thickness close to the constant.The volume of metalimnion increases over time and is inversely proportional to height diameter ratio of the storage tank.The result can be referred for the design of cooling storage and the research of cool storage system.