An analytical equation of state has been previously modified by Papari et al. for representing the volumetric properties of molecular fluids. However the performance of that EOS has not been yet well investigated for refrigerant fluids. This study extended that equation to 19 liquid refrigerants to predict their densities at isothermal and saturated states. Two temperature-independent parameter...

The present work is the successful extension of an improved equation of state (EOS) to refrigerant fluids. The objective is the prediction of isothermal and saturated liquid densities of refrigerants. Two temperature-independent parameters appearing in the modified EOS are closely related to critical point properties of refrigerant fluids. Our results showed that, the proposed EOS can predict w...

In the present study, the local characteristics of pressure drop and heat transfer are investigated experimentally for the condensation of a pure refrigerant R134a in multi-port extruded tubes of 8 channels in 1.36mm hydraulic diameter and 19 channels in 0.80mm hydraulic diameter. The experimental data of frictional pressure drop (F.P.D.) and condensation heat transfer coefficient (H.T.C.) are ...

‎we present an application of the dual gabor frames to image‎ ‎processing‎. ‎our algorithm is based on finding some dual gabor‎ ‎frame generators which reconstructs accurately the elements of the‎ ‎underlying hilbert space‎. ‎the advantages of these duals‎ ‎constructed by a polynomial of gabor frame generators are compared‎ ‎with their canonical dual‎.

In the present study, the condensation and evaporation heat transfer performance of a zeotropic refrigerant mixture (HFC32/HFC125/HFC134a) inside horizontal tubes with smooth, grooved or cross·grooved inner surfaces was investigated experimentally. The cross-gTOoved tube showed the highest heat transfer coefficient for both condensation and evaporation with the zeotropic mixture. Its heat trans...

Vapor refrigerant injection cycle with a flash tank has proven to be effective in improving system performance significantly at extremely low and high ambient temperatures. However, the control strategy of operating the system is still unclear. There is no open publication on the comprehensive study of the vapor injection cycle control strategy to date. This paper presents the experimental inve...

Nowadays, in some small and medium-sized heat pumps, refrigerant R410A has been used widely because of the good thermodynamic performance and environmental protection. Firstly the principles of the system and the characteristics of refrigerant has been demonstrates. The paper has set up a heat pump system with the refrigerant R410A and the performance parameters under different working conditio...

This paper deals with the investigation of substitutes for R-22 and their heat transfer behaviour in a plate-type evaporator with a falling water film as heat source. Alternatives investigated were R-134a and two new refrigerant mixtures. Measurements on a 3m x 0,5m plate showed a superior performance ofR-134a compared to R-22 and mixtures at equal test conditions and a distinct difference betw...

Title of Document Application of Plate Heat Exchanger for Low Temperature Lift Heat Pump Systems Song Li, Master of Science, 2012 Advisor Professor Reinhard Radermacher, Department of Mechanical Engineering In this thesis I investigated the energy saving potential of a low temperature lift heat pump (LTLHP) such as water source heat pump (WSHP), and studied the utilization of a plate heat excha...

An experimental performance comparison study on domestic refrigerator system was conducted and compared with HFC134a and M09 (HFC134a and HC blend (containing 55.2%HC600a and 44.8%HC290 by weight)) mixture refrigerant. The domestic refrigerator system was initially designed to operate with HFC134a.Experimental results showed that the refrigeration capacity of the refrigerant M09 mixture system ...