Optimal Design and Parameter Estimation for Small Solar Heating and Cooling Systems

Abstract

The use of solar heating and cooling systems has evolved from being limited to heating and hot water systems in the past to an increasing application in cooling systems. Furthermore, the efficiency optimization of solar heating and cooling systems is crucial in their design and control. This study aimed to enhance the overall efficiency of a solar heating and cooling system through simulations based on optimal design parameters. Additionally, simulations were conducted to optimize the control system to improve the efficiency of the entire solar heating and cooling system. The framework for control optimization can be summarized as follows: (1) modeling the components of the solar heating and cooling system using the Modelica language; (2) establishing baseline efficiencies for the solar heating and cooling system throughout the year; and (3) implementing a control logic, such as Fuzzy or proportional-integral-derivative (PID), within the system components. The resulting optimal control strategy for the solar heating and cooling system led to a maximum increase in the overall system efficiency of approximately 12% during a week of summer design days, reducing the energy consumption from 696.89 kWh to 556.12 kWh. This demonstrates that the developed parameters and control logic improved the overall system performance and achieved efficiency optimization.