Research On The Optimization Of Ice Bucket Structure And The Effect Of Mechanical Subcooling On The Performance Of Ice Makers

Ice machines are widely used in fields such as food preservation,concrete pouring,and cold storage.With the development of ice and snow sports and the implementation of the "peak shifting and valley filling" policy,ice machines have great development prospects.The technological backwardness,low level of specialization,and low energy efficiency of the ice machine industry urgently need improvement.A heat transfer model for the ice making bucket was established based on the physical model of the working process of the ice sheet mechanism ice bucket,with the aim of optimizing the water distribution plate structure and improving ice making efficiency as the starting point.Four operating parameters were defined for water supply icing ratio,icing time ratio,drying time ratio,and deicing time ratio.A design method model for water distribution trays was established for different ice layer thicknesses and ice layer temperature requirements by users.When the ice making time of the tested sheet ice maker is 20 ～ 40 seconds and the required average temperature of the ice layer is-3 ℃,the drying time ratio should be greater than 0.02 ～ 0.06.When the minimum thickness of the ice layer is 0.5mm,the drying time ratio should be less than 0.32 ～ 0.53.Taking the water circulation process of the ice machine as the research object,the trend of changes in water temperature,ice production capacity,etc.with water supply was analyzed,and the design water supply capacity of the circulating water pump was given.When the icing ratio of the water supply reaches 10,the thickness of the ice is maximized.When the icing ratio of the water supply is 3.8 ～ 5.6,the thickness of the ice can reach 98% ～ 99% of its maximum value.Continuously increasing the freezing ratio of water supply has almost no effect on the thickness of ice;Therefore,the water supply can be designed based on a water supply icing ratio of 3.8 ～ 5.6.Establish a design model for the ice bucket area based on the selected water supply volume and water distribution tray structure.By comparing the theoretical and experimental values,the deviation between the theoretical ice bucket area and the actual ice bucket area is19.4%.At this time,the deviations between the theoretical and experimental data of ice layer thickness,ice layer temperature,and inlet water temperature are 8.3%,1.3 ℃,and 0.6 ℃,respectively.The size of the ice bucket can be designed based on the area model in this article.Add mechanical subcooling to the refrigeration system of the ice sheet machine,compare and analyze the changes in the overall COP of the machine with the main auxiliary mass flow rate ratio and the optimal evaporation pressure of the auxiliary system when different ice sheet configurations are equipped with mechanical subcooling systems.For the main system using R404 A vortex compressor and the mechanical subcooling system using R134 a piston compressor configuration,the optimal main auxiliary flow ratio is 3.0 ～ 4.4,the optimal evaporation pressure(temperature)of the mechanical subcooling system is360～400 k Pa(5.84～8.93 ℃),and the optimal subcooling is about 27 ℃.