Development of a novel flow control system with arduino microcontroller embedded in double effect absorption chillers using the LiBr/H2O pair

The purpose of this work is the development and implementation of a flow control strategy for the LiBr/H2O saline recirculation system in double effect absorption chillers to guarantee an optimum operating range. The control strategy was developed using the PID (Proportional-Integral-Derivative) controller hosted on the Arduino prototyping platform. Structural aspects of the double-effect absorption chiller as well as updating the thermophysical properties of the solution LiBr/H2O in real time to better suit the operation of the absorption cooling system were also considered. The proposed strategy enables a low-cost embedded system for gauging, controlling flow and maintaining optimal operating conditions. An experimental analysis was performed using initially pure water for calibration and control strategy testing, followed by the LiBr/H2O solution to show its versatility and operating accuracy in refrigeration absorption chiller. As a main result, the proposed system offers control of flow rates with a resolution of 0.60 L/min for 67% of the flow range provided by the conventional magnetic centrifugal pump recirculation system. (C) 2019 Elsevier Ltd and IIR. All rights reserved.