Buy Your Automatic Refrigerator with Dollars and Sense

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Bacteria in Milk and Artificial Refrigeration for Dairymen

Mode of access: Internet

The Refrigerator Revolution

This paper looks at the history of the refrigerator and how acceptance of this technological innovation was not instant. To become ubiquitous the refrigerator needed the support of a nascent electric power generating industry and the technical development of electric motors

Satellite refrigeration study. Part II TECHNICAL analysis

Low temperature refrigeration system for satellite mounted infrared sensor coolin

COLD AIR REFRIGERATING MACHINES WITH MECHANICAL, THERMAL AND MATERIAL REGENERATION

The cold air refrigerating machines are practically of the same age as the vaporisation- compression-type refrigerating machines, however, the former ones were put in actual operation only during the past decades. As the principal reason for it, their lower economi- cal efficiency can be considered. However, the vaporisation-compression-type refrigerating machines cause heavy pollution to the environment (gap of ozone layer problem), there- fore the interest in the cold air refrigerating machines has been greatly aroused lately. In the paper, the operation, theory and application possibilities of the cold air refrigerating machines are dealt with, especially considering the air- conditioning of motor vehicles. The improvement of the economy of cold air refrigerating machines is especially paid great attention in this paper. In addition, the possibilities of applying heat exchangers, as well as the cooling process of the operating-medium during compression with the help of liquid charge are examined

Energy assessment and environmental impact analysis of an R134a/R744 cascade refrigeration plant upgraded with the low-GWP refrigerants R152a, R1234ze(E), propane (R290) and propylene (R1270)

The European limitations associated with the use of fluorinated refrigerants have affected one of the most extended solutions used in commercial refrigeration in warm countries. Traditional cascade systems with R404A or R134a, in the high-temperature cycle, and R744 (CO2), in the low side, will be prohibited from 2022 onwards unless the refrigerants used have a GWP100 lower than 150. Since practically all the available refrigerants with low-GWP100 are flammable, a simple but effective modification can be adopted upgrading the current direct expansion system to an indirect one. Accordingly, the aim of this work is to determine the energy and environmental impact of converting an R134a/CO2 direct expansion cascade to an indirect one using the low-GWP100 refrigerants R152a, R1234ze(E), R290 and R1270. The experimental analysis is performed at three different heat rejection temperatures (from 23.3 to 43.6 °C), maintaining the cooling service product at temperatures of 2 °C and −20 °C on average