China
Africa
Explore chapters and articles related to this topic
Chemicals from Paraffin Hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
Carbon tetrachloride is used to produce chlorofluorocarbons (CFCs), such as trichlorofluoromethane (CCl3F) and dichlorodifluoromethane (CC12F2)) by the reaction with hydrogen fluoride using an antimony pentachloride (SbC15) catalyst: CCl4+HF→CCl3F+2HClCC14+2HF→CC12F2+2HC1
Introduction to Convection
Published in William S. Janna, Engineering Heat Transfer, 2018
Dichlorodifluoromethane is used in refrigeration and air-conditioning systems and is more commonly known as Freon-12. Using the data in Appendix Table C.3 for Freon-12, verify the value shown for the volumetric thermal-expansion coefficient. Repeat the calculations for helium at 400 K.
Refrigerants
Published in Vasile Minea, Industrial Heat Pump-Assisted Wood Drying, 2018
Chlorofluorocarbons (CFCs) such as CFC-11 (trichlorofluorométhane) and CFC-12 (dichlorodifluoromethane) have a strong destructive impact on the ozone layer if released into the atmosphere and important influence upon the global warming; the manufacture of these refrigerants was already discontinued in January 1996.
Numerical investigation of flashing of propane (R-290) in a helical capillary tube
Published in Numerical Heat Transfer, Part A: Applications, 2023
Soumik Bose, Sofen Kumar Jena, Sewan Das Patle
Prajapati et al. [26] have studied the expansion of R-134a refrigerant in an adiabatic capillary tube. They have performed the multiphase modeling using the volume of fluid (VoF) approach. They have considered Lee model [27] for the mass transfer rate during the phase change process. They have addressed the unsteady nature of the flow in their study. However, for R-134a refrigerant, they have approximated the phase properties by the polynomial equations. In their study, some fluid properties are the sole function of temperature, while few others are the sole function of pressure. This relationship is forbidden for a universal refrigerant flow simulation, where the fluid properties are strong functions of both pressure and temperature. These approximations of Prajapati et al. [26] result in a significant deviation of their proposed model from the experimental data of Li et al. [28]. Ingle et al. [29] have studied the two-phase flow of refrigerant through a straight capillary tube. They have used a mixture model for multiphase flow and considered ZGB model [30] for mass transfer during phase change. Results of Ingle et al. [29] are closely matched the experimental data of Chen et al. [11]. But this study is limited to flow in a straight capillary tube having a diameter of with R-12 refrigerant. R-12 (Dichlorodifluoromethane) depletes the ozone layer and comes under the CFC group. The global warming potential (GWP) of R-12 is 10900, which has a high environmental threat. Further, the refrigerating effect of R-12 per pound of its weight is low compared to the other refrigerants. R-12 is almost abandoned for use in modern cooling systems. Also, the operating pressures in the work of Ingle et al. [29] are very less compared to operating pressure regimes of actual commercial devices. Alok and Sahu [31] studied the expansion of isobutane inside an adiabatic capillary tube. This study is similar to the work of Prajapati et al. [26]. It does not contain detailed information about the CFD modeling approach and other details for practical applications.