Modeling and Optimizing the Water Intake Side of Absorption Refrigeration System Based on Equivalent Thermodynamic Coefficient

Abstract

Simulation is an important way of studying the performance of absorption refrigeration systems. However, considering numerous influencing factors, existing studies mainly focus on a single device of the system and less on the coupling relationship between devices. To integrate and optimize the water intake side of the absorption chiller and improve the energy efficiency of the system, the study selected the integration of the absorption chiller, the cooling water supply and the return, and river water intake system as the research object and the absorption refrigeration system of Chongqing Danzishi CBD Energy Station as an example. A novel method for constructing the river water temperature prediction model was proposed. Then, the mathematical model of the absorption chiller and the water intake side of the transmission and distribution system was established via the data fitting method, and the accuracy was verified. Finally, the equivalent thermodynamic coefficient model was created and used to optimize the flow and temperature difference between the supply and return cooling water under different inlet temperatures of the cooling water and load rates of the absorption chiller. Results show that, (1) The cooling water inlet temperature has minimal effect on the optimal temperature difference between the supply and return water, and the load rate of the absorption chiller has a great influence. (2) When the absorption chiller operates at full load, the optimum temperature difference between the supply and return cooling water is 10 °C, the optimum water intake flow is 87.80% of the rated flow, and the thermodynamic coefficient of the system can be increased by 14.40% after integration and optimization. The study shows that the energy efficiency of the water intake side of the absorption refrigeration system can be improved by creating a model on the basis of the equivalent thermodynamic coefficient and by applying it to the optimization. This method is fast, simple, and effective. To a certain extent, this study provides technical support for the further improvement of the energy efficiency of absorption refrigeration systems.