Transport Phenomenon Improvement Using Induce Draught in Cold Storage

Abstract

Air is heat transport medium in cold storage operation and its distribution plays a vital role in preservation of agricultural products like fruits and vegetables with desired quality. Thermal behaviours of cold storage system are based on air transport arrangements. Convective heat transfer from stored perishable stuff to cooling system within the chamber is subjected to airflow and its distribution. Transport characteristics can handle with axillary arrangements such as induce draught system. Experimental investigation for impact of induce draught on air transportation is carried out in a 1/4th reduced scaled model of the cold storage [size 6 m (l) × 4 m (w) × 4 m (h)] at HT Laboratory, MANIT, Bhopal. Air transport velocity was measured at 96 stations in the chamber with hot wire anemometer. Measurements indicate supply air approaches rear section of the chamber comparatively at higher velocity with induce draught. Markable improvement noticed with slotted duct wall which boosts airflow velocity by three times at mid-sections compare without induces draught. Overall 1.5 times to three times better supply airflow velocity observed in the chamber, as compare to general configuration, while return air velocity measured almost double during the experiment. Experimental results suggests shift of turbulence mixing of air from evaporator side to central zone of the chamber. Better mixing of air can help in a fast setting of thermodynamic equilibrium in the chamber. It will lead to homogenous thermal environment which can extend the life of perishable goods with maintaining their quality.