Vaccine Transport Kit using Mini DC Rotary Compression Refrigeration System

Refrigeration compressors powered by direct current electrical energy have been banished to mobile refrigeration systems, where batteries are the source of power. Mobile refrigeration and portable cooling have been re-energized creating new opportunities for innovative appliances that do not rely on grid power. These portable refrigeration systems may be applied to medicinal transport kits which have capabilities to cool vaccines. Vaccines are susceptible to heat and light. In this case, they require low storage temperature that would range between 2°C to 8°C. The primary aim of this study is to make use of a mini rotary compressor that will be used for a medical transport kit which can cool vaccines in transit to remote and mountainous off grid areas. The compressor is fitted into a vapor compression refrigeration system using tetraflouroethane as refrigerant. The system used a dc rotary compressor with 56.0 mm in diameter, 78.0 mm in height, and weighs 600.0 grams. The rotary compressor has a rolling piston design with a displacement of 1.40 milliliters and is powered by a high-torque brushless 24V DC motor. The design is very small, lightweight, and relatively high in cooling effect. The rotary compressor is powered by a battery and controlled with a potentiometer to vary the angular velocity. It was observed that the optimal cooling effect for vaccine kit operating the system is with the 3,000 rpm and with the capillary tube hydraulic diameter of 0.91 mm. For efficient performance, this design is adaptable to variable speed operation up to 6,000 rpm.