Development Of Different Temperature Of Cool Storage Agent For The Storage And Transportation Of Food

With the improvement of life degree and the change of consumption habit,more requirement were proposed in the facet of food quality,consumption,pollution,price and the selling period.So the pre-cold in source area,refrigerated shipment requirement were steadily broaden.Therefore,the development of food cold chain logistics industry has become particularly important.Phase change material as the key storage technology has been widely used in building,peak load shifting,solar energy and other fields.The cool storage agent has been applied for the cold chain transportation of food with the development of cold chain logistics.By analyzing cool storage agent in different temperature,we find there exits some problems,such as improper phase transition temperature and low phase change latent heat for using cool storage agent under cold storage?-3^-5??,mild frozen?-12^-14??and rapid freezing?-18^-20??.This paper is mainly to develop a series of cool storage agent with different phase change temperature and high phase change latent heat at low cost.The thermophysical thermal properties of potassium carbonate?KCl?,ammonium chloride?NH₄Cl?,potassium nitrate?KNO₃?,sodium carbonate?Na₂CO₃?,mannitol(C₆H₁₄O₆),sodium formate?HCOONa?and calcium lactate(C₆H₁₀CaO₆)are measured by DSC,and the composition of the cool storage agent is determined at different temperature range.We have studied the cool storage agent in different temperature range.The cool storage agent at the temperature range of-3^-5? is based on KNO₃ solution,mixing with varying concentrations of Na₂CO₃,C₆H₁₄O₆,C₆H?10?CaO₆.The results show that the optimum ratio of KNO3 is 3 wt%,C₆H₁₀CaO₆ 1³ wt%,and water the rest,the phase change latent heat and Onset temperature is 303.0³18.6 J/g and-3.88^-4.12?,respectively.The cool storage agent at the temperature range of-12^-14? is based on KCl solution,mixing with varying concentrations of KNO₃,Na₂CO₃,C₆H₁₄O₆ and C₆H₁₀CaO₆.The results show that the optimum ratio of KCl is 15 wt%,Na₂CO₃ 1⁷ wt%,and water the rest,the phase change latent heat and Onset temperature is 289.8³02.8 J/g and-12.85^-13.30?,respectively.The cool storage agent at the temperature range of-18^-20? is based on NH₄Cl solution,mixing with varying concentrations of KNO₃,C₆H₁₄O₆ and C₆H₁₀CaO₆.The results show that the optimum ratio of NH₄Cl is 15 wt%,KNO₃ 5-7 wt%,and water the rest,the phase change latent heat and Onset temperature is 297.3^-299.9 J/g and-17.80^-17.94?,respectively.When phase change materials consist of multiple components,phase separation may occur after reusing,resulting in the decreased thermal properties.However,phase change materials will turn a solid into to a liquid in phase change process when they are liquids.The product is easily contaminated in the occasion of package broken.In this paper,the cool storage agent is modified by sodium carboxymethyl cellulose?CMC?.After the addition of CMC to cool storage agent in different temperature range,the optimum ratio is: 1.3 wt% KNO₃,1 wt% C₆H₁₀CaO₆,3 wt% CMC,water the rest,the latent heat of the phase change is 308.2 J/g,the Onset temperature is-3.79? corresponding to the cool storage at the temperature range of-3 ^-5?.2.18 wt% KCl,5 wt% of Na₂CO₃ and 3 wt% CMC,water the rest,the phase change latent heat is 287.6 J/g,Onset temperature is-13.30? corresponding to the cool storage at the temperature range of-12^-14?.3.15 wt% NH₄Cl,5 wt% KNO₃ and 3 wt% CMC,water the rest,the phase change latent heat is 298.6 J/g,the Onset temperature is-18.67? corresponding to the cool storage at the temperature range of-18^-20?.