Refrigeration fluids

Some operations need to be carried out at low temperature, which requires refrigeration. The refrigeration fluid might, for example, be propylene and present a major hazard. Operation of the process at a... 

For refrigeration compressors Miscibility with the refrigeration fluids (including compressors with the new refrigeration fluids) Adapted composition... 

Engine Expansion Cycle. In this process, a refrigerant fluid is compressed, optionally precooled, and expanded to a lower pressure through an expander while producing work to reduce both the enthalpy and temperature of the fluid. The expanded refrigerant fluid is warmed to provide cryogenic refrigeration. 

Where a secondary refrigerant fluid is to be circulated, and the working temperatures are at or below 0°C, then some form of nonfreeze mixture must be used. These are collectively termed brines. 

Uses Chlorine is used for water purification and in decreasing amounts for pulp and paper bleaching. Some is used for metallurgical purposes such as metal extraction. Its largest use is for the production of organic compounds used in plastics, pesticides, herbicides, refrigeration fluids, solvents, and others. 

C05-0071. Freons (CFCs) are compounds that contain carbon, chlorine, and fluorine in various proportions. They are used as foaming agents, propellants, and refrigeration fluids. Freons are controversial because of the damage they do to the ozone layer in the stratosphere. A 2.55-g sample of a particular Freon in a 1.50-L bulb at 25.0 °C has a pressure of 262 torr. What is the molar mass and formula of the compound ... 

Occupational hygiene aspects on the safe use and selection of refrigerant fluids... 

Figure 24.23a again shows a simple compression cycle involving a pure refrigerant fluid, but now with an... 

In principle, ammonia is the best refrigerant fluid in terms of power requirement. However, this conclusion disregards the potential practical problems associated with compression. There is little to choose between propylene and propane in terms of the power requirements. 

Absorption refrigeration is much less common than compression refrigeration. Absorption refrigeration powers by compressing the refrigerant fluid dissolved in a solvent using a pump. 

Estimate the power required to reject 1 MW of cooling duty to cooling water with a return temperature of 40°C. Assume A Tmin = 5°C for the refrigeration evaporator and Arml = 10°C for the condenser. Suggest suitable refrigeration fluids for these two duties using Figure 24.35. 

At issue is a group of man-made chemicals called chlorofluorocarbons (CFCs), which are used as the refrigeration fluids (Freon) in the air-conditioning and refrigeration units of automobiles, homes, and industry and which, in the past, were used as the pressure gas in spray cans of paint, deodorants, and so forth. There are a number of compounds containing... 

Carbon tetrachloride does not occur naturally but has been produced in large quantities to make refrigeration fluid and propellants for aerosol cans. Since many refrigerants and aerosol propellants have been found to affect the earth s ozone layer, the production of these chemicals is being phased out. Consequently, the manufacture and use of carbon tetrachloride will probably decline a great deal in the future. 

Distribute >15 thermocouples over the shelf surface, and at the refrigerant fluid inlet and outlet. 

The food compartment of a refrigerator is cooled by vaporization of the refrigerating fluid because vaporization is a cooling process. 

Benning, A.F., McHamess, R.C. (1940) Thermodynamic properties of fluorochloromethanes and ethanes. Ind. Eng. Chem. 32,497-499. Beyerlein, A.L., DesMarteau, D.D., Kul, I., Zhao, G. (1998) Properties of novel fluorinated compounds and their mixtures as alternative refrigerants. Fluid Phase Equilibria 150-151, 287-296. 

Lastly, as CFC refrigerant fluids are being phased out of refrigeration systems and other refrigerant fluids substituted, the reactivity of the substitute material with process materials must be evaluated. 

Select the type of utilities, namely the steam pressures and the temperature of recycled water, as well as the use of inert gas and refrigeration fluids. 

The workimg medium in refrigeration systems is called the refrigerant. Fluids used for this purpose should ideally be nontoxic and chemically inert, with low boiling points93,94. They should have high enthalpies of vaporization per unit mass, high vapor densities and low miscibilities with water, since the latter can lead to freezeup in the expansion devices or corrosion. 

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