24 June 2014

Development of a Control Strategy to Maximize System Performance for Heat Pump Systems

In this paper, a new control strategy is proposed and applied to an adsorption heat pump system as an example. A 3 kW capacity adsorption heat pump using zeolite was constructed and powered by waste heat from a 4 kW internal combustion engine. Over 145
test points were obtained under various ambient conditions, chilled water temperatures, adsorption time and heat recovery time. To extend the range of data to a complete design
space, those test points were used to develop a model using a sophisticated interpolation technique called the Kriging method. The Kriging model predicted the system COP, capacity,
etc., based on a full factorial expansion of the four inputs. With the help of the model, multiple-coefficient curve fit functions were created to simulate COP, adsorption time and heat recovery time depending on the evaporating, condensing temperatures and cooling
capacity. Those functions served as the control strategy to determine the optimal adsorption and heat recovery time associated with maximum COP. The developed control strategy was
evaluated by the test facility and demonstrated a good accuracy of ±10% as compared with experimental data.