Indian Journal of Cryogenics

Reefer containers are used for transportation of perishable goods in temperature-controlled environment. SHIVAY (Sheetal Vahak Yantra) is Liquid Nitrogen (LN₂) based reefer container with temperature range from -40°C to 8°C. A PLC based control system has been developed for this container. The PLC is mainly used for auto-control logic implementation and sequence control of different sub-systems. In addition, a human-machine interface (HMI) is used to input system parameters, monitor the system status, system health & logging of data. This system has been installed on 20 feet container & tested for its operation on 3000 km of road trials. The system was able to maintaine temperature inside the container within ±1.5°C without human interventions. Both software and hardware-based implementations of our system are described in this paper.