Study on the characteristics of charging/discharging processes in three-phase energy storage coupling in solar air conditioning system

Abstract

A new combination system of “three-phase energy storage” and solar absorption refrigeration has been developed in this paper. The operation process of LiBr-H2O three-phase energy storage system is described in detail. Thermodynamic analysis models of charging/discharging processes based on the absorption principle are established in order to understand the dynamic characteristics of three-phase energy storage and release processes. The dynamic simulations of charging/discharging processes are carried out by using MATLAB. The influences of operation parameters on the characteristic parameters of three-phase charging/discharging are analyzed, and the performance evaluation indexes of three-phase energy storage system are obtained. The simulation results showed that the lower initial concentration of LiBr-H2O solution, the smaller mass flow rate of LiBr-H2O sprayed on the heat exchanger in the energy storage tank and the higher heat conductance of the heat exchanger (KA) result in the higher energy storage efficiency and energy storage density. The smaller mass flow rates of LiBr-H2O and the cooling water can make the more stable discharging process with longer cooling time. The research results can provide theoretical guidance for further improving and optimizing the operation performance of three-phase energy storage system coupling in solar air conditioning.