Vapor compression refrigeration

Natural gas Hquids are recovered from natural gas using condensation processes, absorption (qv) processes employing hydrocarbon Hquids similar to gasoline or kerosene as the absorber oil, or soHd-bed adsorption (qv) processes using adsorbants such as siHca, molecular sieves, or activated charcoal. Eor condensation processes, cooling can be provided by refrigeration units which frequently use vapor-compression cycles with propane as the refrigerant or by... 

Vapor-Compression Cycles The most widely used refrigeration principle is vapor compression. Isothermal processes are realized through isobaric evaporation and condensation in the tubes. Standard vapor compression refrigeration cycle (counterclockwise Ranldne cycle) is marked in Fig. ll-72<7) by I, 2, 3, 4. 

Although the T-s diagram is veiy useful for thermodynamic analysis, the pressure enthalpy diagram is used much more in refrigeration practice due to the fact that both evaporation and condensation are isobaric processes so that heat exchanged is equal to enthalpy difference A( = Ah. For the ideal, isentropic compression, the work could be also presented as enthalpy difference AW = Ah. The vapor compression cycle (Ranldne) is presented in Fig. H-73 in p-h coordinates. 

FIG. 13-2 Complex distillation operations with single columns, a) Use of intermediate heat exchangers, (h) Coupling of intermediate heat exchangers with heat pump, (c) Heat pump with external refrigerant, (d) Heat pump with vapor compression, (e) Heat pump with hottoms flashing. 

Conventional refrigeration is based on the evaporation of a refrigerant. The evaporator produces cooling, the compressor generates high-pressure energy, and the condenser rejects heat to the environment. An absorption machine differs from a vapor compressor only in the way the refrigerant is compressed from the evaporator to the condenser. 

The term refrigeration refers to the gas coming into contact with evaporator coils on a dx vapor-compression cycle, coils on an absorption cycle, vortex... 

Refrigeration is needed for processes that require temperatures below those that can be economically obtained with cooling water. For temperatures down to around 10 0, chilled water can be used. For lower temperatures, down to -30°C, salt brines (NaCl and CaCF) are used to distribute the refrigeration" around the site from a central refrigeration unit. Vapor compression machines are normally used. 

Equipment diagram for refrigeration using a basic vapor compression cycle. 

Automotive air conditioning systems provide simple heating and cooling/dehuniidification functions. There is no provision for filtration of the air. All current automotive air conditioning utilizes vapor-compression refrigeration systems coupled to the automobile s engine. 

Automotive air conditioning systems using vapor compression refrigeration systems and CFC refriger-... 

Figure 2, the pressure-enthalpy plot of the standard vapor compression cycle, traces the state of the refrigerant through the refrigeration system. (Enthalpy represents the energy of the refrigerant as... 

Vapor compression uses the highest form of energy, namely electrical energy. In absorption refrigeration, the energy input is any source of heat (e.g., electrical energy, bottled gas, kerosene, or solar energy). 

High pressure steam lines Low pressure steam lines Vacuum steam lines Compressed air lines Refrigerant vapor lines High pressure Low pressure Refrigerant liquid Brine lines Ventilating ducts Register grilles... 

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