Three-zone system simulation model of a multiple-chiller plant

This paper presents a system simulation model of an oil-injected screw chiller. The refrigerant (shell and tube) heat exchangers are modeled, using a three-zone approach, to study the effects of the operational parameters on the fractional area allocated to each phase within the heat exchangers. All major components of the system such as, an oil-injected screw compressor, a shell and tube condenser, a flooded evaporator and a high side-float valve, are modeled in a modular format. The predicted results are validated with experimental data collected from a multiple-chiller plant at a process industry. The results show that the part-load ratio and the temperature of glycol-water entering the evaporator affect the system performance significantly and have strong influence on the fractional areas allocated to each phase within the condenser.