Application Of Phase Change Materials Dedicated To Agricultural Products Cold Chain

This research is originated from the uprising need of agricultural products preservation, including long distance transportation of large quantity of perishable products and short distance ones of various kinds and high frequency, along with the lack of technologies in the refrigerated transportation. These reasons have propelled us in developing a series of PCMs (Phase Change Materials) and their accessories and equipments which are dedicated to agricultural supply chain logistics and in providing viable solutions in catering for cold chain missions.We have optimized two types of PCM recipes by adding SAP(Super Absorbent Polymer). Different SAP concentration levels have been tested by DSC on the on-set temperature and latent heat. We found out the best choice of concentration level of 1.2%～1.3% for our developed recipes. Moreover, we have contrasted our PCMs with other ice packs collected in the market and find out our PCMs having better performance over these packs.A series of devices, software and instruction manual were developed to help driving out the potential of our premier PCMs, including ’PCM plate with enhanced efficacy in heat transfer through increased superficial area’, PCM plate lid dedicated for fruit and vegetables baskets’,’Easy-assemblable PCM wall for refrigeration truck dedicated for agricultural product cold chain’,’Instruction manual for application of PCMs dedicated for agricultural product cold chain’, ’Software for calculation of technical parameters of specific cold chain transportation tasks’.Application of our PCM recipes and its accessories are demonstrated in Charpter IV. Freezing time of PCM bags are measured under -20℃ environment with result of 15±4 hours suggested pre-freeze time; Preservation efficacy and time length of three typical foods:mushroom, leechee and frozen salmon are tested through simulation using temperature sensors in getting T-t figures. Results recommended 3:10-5:5 radio of weight of common foods to weight of PCMs,2:1 when it came to high value-added products like lobsters.With the completion of easy-assembling PCM wall, we’ve managed to conduct two separated road tests in figuring out the refrigeration abilities of the truck in preserving 3 diverse kinds of common agricultural products:waxberry, strawberry and kiwifruit. We find out that, with the total PCM weight of 2940 kilograms in the truck, the time of keeping the temperature of strawberries and kiwifruits between 0～10℃ is 158 hours. And also,60% of PCM truck fual costs will be cut down in contrast to the typical mechanical refrigeration in a single transportation mission, endowing our PCM wall strong market competitiveness.