Research on operating characteristics of direct-return chilled water system controlled by variable temperature difference

► AHU thermodynamic model has been built to solve the heat/humidity balance problem. ► Hydraulic calculation models of direct-return pipe network topology has been built. ► Bypass loop has been considered to the analysis for variable flow operation. ► The universal problems for variable flow operation have been analyzed theoretically. ► Energy-saving operation strategies have been researched.