Real-time thermal load calculation by automatic estimation of convection coefficients

Abstract

A significant step in the design of Heating, Ventilating, Air Conditioning, and Refrigeration (HVAC-R) systems is to calculate the room thermal loads which often vary dynamically. A self-adjusting method is proposed for real-time calculation of heating/cooling loads in HVAC-R applications. In this method, the heat balance calculations are improved by real-time temperature data to achieve more accurate load estimations. An iterative mathematical algorithm is developed to adjust the heat transfer coefficients according to live measurements.Accepted analytical correlations are also used to estimate the heat transfer coefficients for comparison with the present model. The adjusted coefficients and the analytical correlations are separately used to estimate the thermal loads in an experimental setup. It is shown that the utilization of the adjusted coefficients yields to higher accuracy of thermal load estimations compared to the conventional analytical correlations. Since the proposed method requires less engineering information of the room, it can be adopted as a simplified yet accurate method for the design and retrofit of new and existing HVAC-R systems.