The purpose of this study is to increase the coefficient of performance (COP) of the split air conditioner (SAC) by reducing the compressor work and increasing cooling capacity which can be achieved with a two phase ejector as an expansion device with novel design dual evaporator temperature. Numerical methods implementing mathematical model developed in EES software. The EES modelling is used to simulate the influence of key parameters of the ejector to overall system performance of the split air conditioner (SAC). Such key parameters include entrainment ratio involving mass flow rate of secondary and primary flow in the ejector and pressure lift ratio comprising pressure in suction and diffuser sections. Performance analysis of the SAC system with a two-phase ejector is performed to reach ASHRAE Standard requirement of a constant COP for SAC application minimum of 3.5. The SAC system simulated is charged with R-290 as the fluid medium of cooling capacity at least 4000 BTU/hr based on numerical model simulation results the ejector is then produced and installed in a modified SAC system. Experimental test system is set to experimentally investigate and comparation analisys the actual performance of the ejector and its effect to the novel design dual evaporator temperature COS-SAC system performance. The SAC system performance with ejector is also found to be significantly improved is about 35 % greater than those of conventional expansion device system.
This paper presents field analyses on the influences of condenser and evaporator approach temperatures of water cooled air conditioning system for a shopping mall. The mall building comprises food and non-food retail stores and uses a centralized air conditioning (AC) system to condition the entire building. The AC system comprises three chillers with the same cooling capacity. Chillers’ performance parameters included power consumption, condensing and evaporating temperatures, evaporator-condenser approach temperatures, pressure drop and cooling capacity parameters were hourly recorded for a period of one year. Performance characteristics of each chiller were evaluated at different condenser and evaporator approach temperatures and regression analyses were also established to examine the correlations and influences of the approach temperatures on the chillers’ performance. The analyses results showed that the increase of condenser approach temperature could increase the power consumption and reduce the coefficient of performance (COP) of the chillers. While evaporator approach temperature was found to have insignificant effect to the chiller performance. The results also showed that for the investigated chillers with condenser and evaporator approach temperatures maintained below 2 K, the approach temperatures had negligible correlation to the power consumption and the overall performance of the chillers. At this operational conditions, the water cooled air conditioning systems could operate at their best possible performance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.