In this paper, the transient model of a water-cooled centrifugal chiller is developed in Modelica with Dymola and the TLK/IfT Library (TIL). The centrifugal compressor is modeled in detail based on the turbomachinery theory. The chiller capacity control is achieved by the combination of variable inlet guide vane (VIGV) and variable speed drive (VSD). The shell-and-tube heat exchangers are discr...

This paper outlines a mathematical modelling approach to predict the steady-state behaviour of finned-coil evaporators. The model was built taking three domains into account: (i) refrigerant flow inside the coil; (ii) heat transfer through the walls; and (iii) air flow through the finned-coil array. The equations were obtained from the mass, momentum and energy conservation principles, mathemat...

This paper presents experimental investigations of the dynamics of a transcritical CO2 heat pump system with two thermal storages for simultaneous cooling and heating application. The preliminary results of the thermal battery are provided using a small-scale test bed that shows the accelerated penetration of renewable energy sources for building heating and cooling applications. The experiment...

The capacity of the refrigerator' is approximately 44 cubic feet. The cabinet is insulated throughout with 4 inches of compressed cork, encased outside with painted plywood and inside with stipple-glazed asbestos sheeting. Internal lighting is provided with automatic operation on opening and closing the doors. Cooling is by means of a Prestcold plate type of evaporator and serviced by a Prestco...

In order to solve the problem of poor refrigeration performance during operation system under low temperature conditions, this paper designs a test bench study effect different air volumes on cooling capacity conditions 32?C outside warehouse and -10?C inside warehouse. The results show that when volume condenser is set 65% unit evaporator 100%, 8.62 kW, compressor power 1.88 COP 4.55 energy ef...

• ORC and compound ejector-multi evaporator vapour compression systems are combined. Nine ultra-low global warming potential refrigerant pairs proposed to replace R134a R245fa. Condenser waste heat recovery increases the overall coefficient of performance. The pair R1234ze(Z)/R1234ze(E) results in highest energy This article evaluates exergy performance a novel dual fluid combined organic Ranki...