The Data Mining Technique Using RapidMiner Software for New Zeotropic Refrigerant

This research presents the development of environmentally-friendly and energy efficient refrigerant for medium temperature refrigeration systems that new azeotropic refrigerant mixture of hydrofluorocarbons and hydrocarbon that can retrofit in the refrigeration system using R404A. The medium back pressure refrigeration testing standard that follow CAN/ANSI/AHRI540 standard air-conditioning, heating, and refrigeration institute (AHRI) and The properties of refrigerants and refrigeration simulation system that used national institute of standards and technology (NIST) reference fluid thermodynamic and transport properties database (REFPROP) software and NIST vapor compression cycle model accounting for refrigerant thermodynamic and transport properties (CYCLE_D-HX) software. The methodology uses decision tree function in datamining by rapid minor software that first of KDnuggets annual software poll that showed new azeotropic refrigerant mixture had cooling capacity, refrigerant effect, GWP and boiling point were lower than R404A but work and pressure for medium temperature refrigeration system of azeotropic refrigerant mixture were higher than R404A. The artificial intelligence (AI) by data mining technic can predictive environmentally-friendly and energy efficient refrigerant for medium temperature refrigeration. The result of refrigerant mixed by R134A, R32, R125 and R1270 and is consistent with the evolution of fourth-generation refrigerants that contain a mixture of HFCs and HCs which are required to produce a low-GWP, zero-ozone-depletion-potential (ODP), high-capacity, low-operating-pressure, and nontoxic refrigerant.

Nanofilm boiling and evaporation of working fluids R32/R1234ze(E) on metal walls: Insights from molecular dynamics simulations

Understanding energy transfer between working fluid and vapor is a critical issue in absorption refrigeration and thermophysics for the aim of intensifying heat conversion. However, it is difficult to achieve by experimental measurements due to the difficulty in catching the detailed and accurate modeling information, e.g., specific working fluid, and its underlying molecular mechanism. In order to study the evaporation and boiling behavior of refrigerant mixture from the microscopic point of view, the nanofilm consisting of different working fluids, with the evaporation model of R32/R1234ze (E) on metal wall, was established by utilizing molecular dynamics (MD) method. The effect of different mole ratios, i.e., pure R32, 3:1, 1:1, 1:3, pure R1234ze (E), on the evaporation and boiling behavior of mixtures was analyzed. The results show that the probability of explosive boiling decreases with the decrease of R32 molecular mole ratios. Thus, in turn, the performance of refrigerant mixture is observed to be better than that of pure refrigerant. Insights from this simulation research could provide an effective reference for the MD interactions and have potential benefit in developing efficient and sustainable processes for industries to minimize the chemical usage and environmental damage.

PENGARUH REFRIGERAN CAMPURAN HALOKARBON DAN HIDROKARBON TERHADAP TEMPERATUR EVAPORATOR

Hydrocarbon refrigerant is a type of environmentally friendly refrigerant but it has disadvantages compared to halocarbon refrigerant which is flammable. The purpose of mixing hydrocarbon refrigerants with halocarbons in the study was to determine the effect of the percentage of the refrigerant mixture on the temperature of the evaporator and reduce its flameability. The percentage of the mass of the mixed refrigerant mixture that is loaded and time is used as the independent variable, the evaporator temperature as the dependent variable. So the relationship between time and evaporator temperature will be known for each percentage of the mass of the refrigerant mixture. Hasil penelitian menunjukkan bahwa komposisi campuran massa refrigeran hidrokarbon dengan halocarbon berpengaruh terhadap laju perubahan temperatur evaporator. Persentase hidrokarbon dalam campuaran refrigeran HC-HCFC semakin besar dapat meningkatkan laju penurunan temperatur pada evaporator. Semakin besar persentase hidrokarbon dapat menghasilkan pencapaian temperatur semakin rendah pada evaporator.