air conditioning refrigerant r134a has value of global warming potential (gwp) 1300, which is much higher than mac directive (gwp below 150) passed in july 2006. this prompted a search for alternative refrigerant with gwp value less than 150. r1234yf is a new refrigerant which has lower gwp value of 4. effect of blower speed has been compared and flammability issue of r1234yf has been addressed...

This paper presents the improvement of eco-friendly and power consumption saving refrigerants for refrigeration systems. The novel azeotropic refrigerant mixtures HFCs HCs can replace systems, using R134, R32, R125, R1270 in several compositions found decision tree function RapidMiner software (which came first KDnuggets annual poll). All results are mixed POE, which is A1 classification refrig...

It is a common misconception that game-based learning is, by its very nature, engaging for the majority of learners. This is not necessarily the case, particularly for learners in Higher Education who may need to be persuaded of the value of learning games. For some learners, games may simply not be perceived as engaging–either in terms of an initial motivation to play or sustained participatio...

In diesem Beitrag wird ein Programm zur effektiven Sicherheitssensibilisierung im Unternehmen entwickelt. Schwerpunkte des Programms liegen auf Bedrohungsszenarien, der Form eines ‚Alternate Reality Game‘ zur Wissensvermittlung und messbaren Erfolgsgrößen. Mithilfe des Programms soll eine dauerhafte Verhaltensänderung erreicht werden.

h = heat transfer coefficient q = heat flux from the wall of evaporator to refrigerant Tw =Temperature at the wall of evaporator Tf = Temperature of the refrigerant kal = Conductivity of aluminum t = Thickness of evaporator M& = Mass flow rate of refrigerant Cp = Constant-pressure specific heat of refrigerant Tsat = Saturation temperature of refrigerant Tin = Temperature of refrigerant at inlet...

This paper presents the experimental research into the evaluation of lubricity for polyolester (POE) lubricant with HFC-134a refrigerant in rotary and reciprocating compressors for household refrigerators. In order to evaluate the lubricity for POE lubricant with HFC-134a refrigerant, we conducted 4-balls wear tests in the mixing environment of POE lubricant and HFC-134a refrigerant. In the pre...

A household refrigerator designed to work with R-134a was used as an investigation unit to assess the prospect of using mixed refrigerants. The recital of the refrigerator using mixed refrigerant was investigated and compared with the performance of refrigerator when R-134a was used as refrigerant. The effect of condenser temperature and evaporator temperature on COP, refrigerating effect was i...

A heat pump system requires proper refrigerant charge amount. Once refrigerant is charged into a heat pump system, its charge amount is fixed. For this reason, prediction of optimal refrigerant charge amount is very important in order to yield best performance. Too low charge amount degrades capacity of heat pump. On the other hand, excessive charge amount decreases coefficient of performance (...

Multi-evaporator vapor compression systems (ME-VCS) provide cooling to multiple zones. The thermodynamic conditions in these zones are independent: the heat loads often differ, and the occupants of these spaces often have different desired room temperatures. Therefore, in order to regulate each zone to its desired setpoint temperature, the amount of thermal energy removed by each evaporator mus...

This research is aimed to define , (1) the effects of refrigerant to the environment, (2) derive the eco friendly refrigerants by using software REFPROP, (3) describe the properties of refrigerant by mixing them in appropriate percentage, (4) reducing GWP and ODP by providing suitable substitute of CFC’s and HCFC’s refrigerants, (5) reducing the effect of refrigerant to the ODP. This analysis i...