Refrigeration.pptx (Size: 311.4 KB / Downloads: 34)
Refrigeration is defined as the branch of science which deals with the process of reducing and maintain temperature of material below the temperature of surrounding.
In non-cyclic refrigeration, cooling is accomplished by melting ice or by subliming ice (frozen carbon dioxide). These methods are used for small-scale refrigeration such as in laboratories and workshops, or in portable coolers.
This consists of a refrigeration cycle, where heat is removed from a low-temperature space or source and rejected to a high-temperature sink with the help of external work, and its inverse, the thermodynamic power cycle.
When the working fluid is a gas that is compressed and expanded but doesn't change phase, the refrigeration cycle is called a gas cycle. Air is most often this working fluid. As there is no condensation and evaporation intended in a gas cycle, components corresponding to the condenser and evaporator in a vapor compression cycle are the hot and cold gas-to-gas heat exchanger in gas cycles.
Thermodynamic cooling uses the peltier effect to create a heat flux between the junction of two different types of materials. This effect is commonly used in camping and portable coolers and for cooling electronic components and small instruments
By the 1870s breweries had become the largest users of commercial refrigeration units
Refrigerated railroad cars were introduced in the US in the 1840s for the short-run transportation of dairy products
Refrigerated vehicles are used to transport perishable goods, such as frozen foods, fruit and vegetables