Search the Community

Use of R290/R170 in Lieu of R22/R23 in Cascade Refrigeration Cycles View File ABSTRACT R22/R23 have been predominantly used in cascade refrigeration cycles. Even though the ODP of R22 is not as high as CFCs, it still will be phased out following the Montreal Protocol and its amendments because of the chlorine atoms. Hydrocarbons, such as R170 and R290 are natural working fluids. Thermodynamic analysis on the cascade refrigeration cycle adopted R290/R170 under the evaporation temperature from -80 to -55 and the condensation temperature from 30 to 40 are processed. System performances, such as the maximum COP, the cascade evaporating temperature, the ratio of refrigerants flow rate between high and low temperature circuits and their variations are compared with that of the R22/R23 under the same conditions. Results show that the performances of the two cascade refrigeration cycle are approximately the same. So the R290/R170 can be used as the substituting refrigerants to R22/R23 in the cascade refrigeration cycle. Submitter Samurai Appliance Repair Man Submitted 09/08/2017 Category Appliance Repair Manual Pot Luck Supper  

Tecumseh Guidelines for Utilization of R600A and R290 View File The use of hydrocarbon (HC) refrigerants R600a (isobutane) and R290 (propane) for replacements for HCFC’s and HFC’s continues around the globe. R600a and R290 have ozone depletion potential (ODP) factors of zero (0.0) and a fraction of the global warming potential of those refrigerants they are intended to replace. Both have acceptable toxicity levels; however, both are flammable. Neither of these refrigerants are “drop-in” replacements for HCFC’s or HFC’s. There are significant differences between R600a and R290, and the non-HC refrigerants that must be considered in handling, processing and application. These guidelines are offered to help understand these differences. Submitter Samurai Appliance Repair Man Submitted 09/08/2017 Category Appliance Repair Manual Pot Luck Supper  

Comparison of Cooling Parameters of R134a and R290/R600a View File Abstract: Cooling capacities and other parameters were determined for a refrigeration cycle operating between temperature limits of -25oC (evaporator temperature) and 42oC (condenser temperature). The refrigerants used in the refrigeration cycle analysis were R134a and R290/R600a. Compressor capacity of 125W, degree of subcooling of 9K and degree of superheating of 15K were maintained for refrigeration cycles using R134a and a binary mixture of R290/R600a (50% each by mass). Parameters such as refrigerating capacity, mass flow rate, compression work, condenser capacity and Coefficient Of Performance (COP) were computed for each refrigeration cycle. Flow rate of R134a is higher than that of R290/R600a which indicates its low evaporative specific heat. The cooling capacity of R134a (376.41W) is higher than that of R290/R600a (338.11W). COP of the cycle using R134a is 3.01 which is higher than that of R290/R600a. Suction and discharge pressures of the two refrigerants are fairly close. The analysis showed that cooling capacities of the two refrigerants are close enough and are therefore proposed as substitutes in existing R12 refrigeration systems. Keywords: Refrigeration Cycle, R134a, R290/R600a, Cooling Capacities, Binary Refrigerants Submitter Samurai Appliance Repair Man Submitted 09/08/2017 Category Appliance Repair Manual Pot Luck Supper