Refrigeration systems refrigerant composition

Refrigerant composition (refrigeration systems), 231-234, 241 speed-limited, 232-233 horsepower-limited, 233 accumulator relief valve, 233-234 minimum suction pressure, 234 Refrigerant condenser problems (evaporating problems), 240 Refrigeration systems, 227-241 efficiency, 227-229 diagnosing compressor problems, 229—231 refrigerant composition, 231—234 ... 

As with heat pumping, the grand composite curve is used to assess how much heat from the process needs to be extracted into the refrigeration system and where, if appropriate, the process can... 

This standard provides an unambiguous system for numbering refrigerants and assigning composition-designating prefixes for refrigerants. Safety classifications based on toxicity and flammability data are included. [from Section... 

Each system and its particular requirements must be evaluated from a composite of the conditions affecting the refrigerant. After a refrigerant is selected, the accepted design procedure and materials of construction can be applied. 

Deformable bodies, flow past, 11 775-777 Deformation, defined, 21 702 Deformation maps, 13 479-480 Deformation processing, of metal-matrix composites, 16 169-171 Deformation strain, 13 473 Defrost controllers, in refrigeration systems, 21 540... 

A common example of syneresis is found when a mold of gelatin remains under refrigeration for a period. A general shrinkage of the body of the gel occurs and a liquid collects around the edge of the mold. Hie liquid is a dilute solution of the original composition. Since the total volume of the system remains (he same, syneresis should not he considered simply as the opposite of imbibition (absorption). Extending the onset of syneresis in various products, notably foods, is of obvious importance. 

Ethylene oxide at a composition of 12% by weight with UCON refrigerant 12 (Oxyfume-12, Union Carbide Corp.) is nonflammable and can be used safely in a closed system. The effectiveness of this commercial mixture depends on the amount of ethylene oxide present, the temperature of its application, the time of exposure, and the relative humidity in the chamber (1,2,3). 

ARS minimizes refrigeration energy by using distributed distillation and simultaneous heat and mass transfer in the dephlegmator (exclusive arrangement with Air Products) or HRS system. Two C2 streams of varying composition are produced. Hydrogen and methane are separated overhead. 

Alany existing applications involve small adsorption systems for home and automobile applications, eg, refrigerant drying in automobile air conditioners, dual-pane window desiccants, medical oxygen systems, and muffler corrosion protection. Such small adsorption systems will continue to be developed for new uses in indoor air pollution and odor abatement and for the enhancement of the performance of other equipment and appliances. For example, adsorption-based control of the composition of air in refrigerators can provide improvements in the storage of fruits and vegetables. 

Figure 4.4-1 Basic composition of an apparatus for matrix-isolation experiments a) Rotatable cryostat with gas-handling system, b) Sectional view in the level of the matrix support, (1) matrix support, (2) refrigerator, 4-40 K, (3) radiation shield, 77 K, (4) vacuum shroud, (5) infrared window, X KBr, y PE, z quartz glass, (6) spray-on nozzle, (7) synthetic device, e.g., Knudsen cell, (8) turbomolecular pump, p < 10 mbar, (9) to backing pump, (10) transfer line, quartz or stainless steel capillary, (11) needle valve, (12) inert gas inlet, Ne, Ar, N2,..., (13) bulb for gas mixtures, (14) capacity manometer, (15) sample, (16) to high-vacuum system.

The bypassed vapor heats up the liquid there, thereby causing the pressure to rise. WTien the bypass is closed, the pressure falls. Sufficient heat transfer surface is provided to subcool the condensate, (f) Vapor bypass between the condenser and the accumulator, with the condenser near ground level for the ease of maintenance When the pressure in the tower falls, the bypass valve opens, and the subcooled liquid in the drum heats up and is forced by its vapor pressure back into the condenser. Because of the smaller surface now exposed to the vapor, the rate of condensation is decreased and consequently the tower pressure increases to the preset value. With normal subcooling, obtained with some excess surface, a difference of 10-15 ft in levels of drum and condenser is sufficient for good control, (g) Cascade control The same system as case (a), but with addition of a TC (or composition controller) that resets the reflux flow rate, (h) Reflux rate on a differential temperature controller. Ensures constant internal reflux rate even when the performance of the condenser fluctuates, (i) Reflux is provided by a separate partial condenser on TC. It may be mounted on top of the column as shown or inside the column or installed with its own accumulator and reflux pump in the usual way. The overhead product is handled by an alter condenser which can be operated with refrigerant if required to handle low boiling components. 

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