As of 2011, R-134a systems were banned and applied to all new models, and as of 2017, to all cars in European countries because the indirect radioactive effect for GWP is 1300 as tabulated in Table 1. Table 1. Ozone depleting potential (ODP), global warming potential (GWP) and other ...
In order to eliminate the drawbacks of the liquid-suction/internal heat exchanger, some researchers proposed a mechanical subcooling method to enhance the system COP and decrease the superheated degree as well. As shown in Fig. 30 [175], in the mechanical subcooling method, a small VCRS is ...
Table 2 - Pressure Drop In Liquid Lines By Refrigerant1 Refrigerant R-22 R-407C R-410A R-134a Pressure Drop PSI/ft (kPa/m) Riser 0.50 (11.31) 0.47 (10.63) 0.43 (9.73) 0.50 (11.31) Only sub-cooled liquid refrigerant will avoid flashing at the TX valve in this situation. If the ...
Detailed refrigerant properties for the alternatives in Table I are missing, however, except for a few. Here attention is drawn to HFC134a in particular, as this refrigerant is assumed to become one of the main refrigerants in the future. Figure 1 expresses theoretical COP relative to CFC-12 ...
High-temperature superheated vapor flows through an anti-condensation loop and is cooled to state 6′. Thereafter, R290 vapor enters the condenser. Cooled by external air, high-temperature R290 vapor is cooled to a saturated state 7. It gets further cooled before entering a high-temperature ...
Experimental data from a TXV system with two combinations of refrigerant and lubricant: R134a and PAG46, R1234yf and PAG46, were used to validate the model. Employing the “thermodynamic approach” and correlations independent of refrigerant and oil type, this model could be generalized to most...
This article present an experimental investigation of varied mass charges of Liquefied Petroleum Gas (40 g, 50 g, 60 g and 70 g) enhanced with varied TiO2 nanoparticle/mineral oil concentrations (0.2 g/L, 0.4 g/L and 0.6 g/L nano-lubricants) in a R134a compressor of a domestic refriger...
Table 4. Gaseous state R134a refrigerant properties. For the gaseous state of R134a coolant, the specific constant ℜR134a can be determined with Equation (1): ℜ𝑅134𝑎=𝑝𝑅134𝑎1𝜌𝑅134𝑎𝑍𝑐𝑅134𝑎𝑇𝑅134𝑎,ℜR134a=pR134a1ρR134aZcR134aTR134a, (1) ...
In addition, as OD was lower than the optimal value, the refrigerant drawn by the compressor was superheated vapor and its superheating degree increased with decrease in EEV opening degree, resulting in a slight reduction in cooling capacity. Under the excessive charge condition, Pdis sharply ...
Because the refrigerant in most areas of the cycle was in the superheated states, although the compressor pressure ratio was approximate, a larger suctioning superheat will certainly cause a worse isentropic efficiency and a higher discharge temperature. This result can be also confirmed by the ...