PRODUCT-COOLING LOAD AND MOISTURE LOSS UNDER DIFFERENT LOADING PATTERNS AND COOLING RATES OF POTATOES IN COLD STORAGE
Product-cooling load is one of the most important components, contributing about two-thirds toward the total refrigeration load during the transient cooling period of a cold storage. Therefore, time-variable behavior of product-cooling load is necessary for the efficient design and operation of a refrigeration system. A well-designed refrigeration system not only avoids wastage of electrical energy but also restricts the moisture loss within permissible limit. In the present study, a total of 15 combinations, with three cooling rates and five loading patterns, were investigated and corresponding product-cooling loads were predicted. The effect of cooling rates was studied on moisture loss as well. It was found that although the high cooling rate gave low moisture loss, it required a high capacity refrigeration system, which might not be justifiable over the reduced moisture loss during the long-term storage period. Loading rate of the product also had a similar effect on refrigeration load as that of cooling rate. A cooling rate corresponding to half cooling time of 6.72 days (cool-down time = 30 days) in combination with linearly decreasing product loading rate of 30 days duration gave the minimum refrigeration load with affordable increased moisture loss, which could be adopted in commercial potato cold storage. PRACTICAL APPLICATIONS
The results of the present study highlight the interdependence of two different but most burning problems of the Indian potato cold storage industry, i.e., higher electrical power consumption and storage losses beyond permissible limits. The quantitative information of product-cooling load under different combinations of loading patterns and cooling rates would enable the operators of cold storage in managing these parameters within the installed refrigeration capacity in order to avoid fluctuation in temperature of storage air and resultant storage losses.
Document Type: Research Article
Affiliations: Agricultural and Food Engineering DepartmentIndian Institute of TechnologyWest Bengal, India
Publication date: 2008-06-01