Experimental investigation was done to find the role of capillary tube length and amount of refrigerant charge on the overall heat transfer coefficient in condenser and evaporator and actual COP of a simple vapour compression refrigeration system. It was concluded that increasing of the refrigerant charge in the system largely enhances the overall heat transfer coefficient in the evaporator by ...

In the present paper an analysis of mixed convection of an unsteady magneto hydrodynamic (MHD) flow of an incompressible viscous fluid through porous media due to a vertical porous stretching sheet in the presence of viscous dissipation, thermal radiation and heat source /sink has been carried out. The fluid considered is viscous and incompressible. The governing partial differential equations ...

Direct expansion (DX) refrigeration technology is almost exclusively used in multi-temperature transport refrigeration systems. Multi-temperature systems use up to three evaporators, requiring large refrigerant charges and system pressure control to operate over a wide range of set-point conditions. Despite incremental design improvements over the past decade, environmental and control issues c...

An experimental investigation was implemented to determine the capacity degradation due to non-uniform refrigerant and air flow distributions, and to assess the potential to recover the lost capacity via controlling refrigerant distribution between individual refrigerant circuits. The tests were performed on a three-circuit, threedepth-row, finned-tube evaporator. Refrigerant inlet quality, exi...

This paper presents a surrogate-assisted framework to solve constrained black-box optimization problems, which is applied the optimal single-mixed refrigerant natural gas liquefaction processes design. approach uses kriging models as cheap-to-evaluate, reliable surrogates of process-simulator-dependent functions problem. From prediction and estimated error, probability feasible improvement acqu...

In this study, a novel dual-nozzle ejector enhanced vapor-compression cycle (DEVC) for solar assisted airsource heat pump systems is proposed. In DEVC, the use of the dual-nozzle ejector for recovering the expansion losses is a very promising approach to improve the cycle performance. A mathematical model of the DEVC is developed to predict its performance under specified operating conditions. ...

Title of dissertation: EXPERIMENTAL AND THEORETICAL INVESTIGATION OF OIL RETENTION IN A CARBON DIOXIDE AIR-CONDITIONING SYSTEM Jun-Pyo Lee, Doctor of Philosophy, 2003 Dissertation directed by: Professor Reinhard Radermacher Department of Mechanical Engineering In a closed loop vapor compression cycle, a small portion of the oil circulates with the refrigerant flow through the cycle components w...

Refrigerator is one of the home appliance utilizing mechanical vapour compression cycle in it process. Performance of the system becomes main issue and many researches are still ongoing to evaluate and improve efficiency of the system. Therefore, this paper presents the development process of refrigerator test rig and performance analysis of a domestic refrigerator. The experiment platform whic...

The use of chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) has been widely restricted. They have been replaced with hydrofluorocarbons (HFCs) in order to protect the ozone layer. However, the leakage of refrigerant into the air from active or end-of-life air conditioners is a serious environmental issue owing to the high global warming potential (GWP) of HFCs. Therefore, replaci...

This research studies the influence of using SiO2 nano-particles 50nm in a Vapor Compression Refrigeration System (VCRS), along with Poly-alkylene Glycol (PAG) oil and R-134a mixed to create nano-refrigerant. In this work, were performed three different concentrations (0.1%, 0.3%, 0.5%) 200ml PAG oil. AVCR system was built at mechanical engineering department laboratory Al-Qadisiyah University ...