Calculation Steps for the Design of Different Components of Heat Pump Dryers Under Constant Drying Rate Condition

Abstract

Heat pump–assisted dryers are an alternative method for drying heat-sensitive food products at low temperature and less relative humidity with lower energy consumption. The mathematical models of a heat pump dryer consist of three submodels; namely, drying models, heat pump models, and performance models. Heat and mass balance of both refrigerant and air circuits in all components of the system are used for development of mathematical models. The models are used for design of different components of heat pump dryers operating under constant drying rate condition. A simple stepwise design procedure for batch-type, closed-loop heat pump dryer is also presented.

Keywords:

• Constant drying rate
• Design calculations
• Drying
• Heat pump
• Mathematical models

ACKNOWLEDGEMENT

The authors are thankful to the Indian Council of Agricultural Research for providing necessary financial support and Orissa University of Agriculture and Technology for providing the infrastructure for the research work.