Refrigeration is one of the leading uses of electric power in the United States. The term "refrigeration" refers to air-conditioning for homes, businesses, and industry and the operation of refrigerators, freezers, and heat pumps. The technology most often used in refrigeration, the vapor compression cycle, is 100 years old, inefficient, and environmentally unsound. Since the 1980s, the refrige...

Ammonia can be applied to any type and size of refrigeration system from domestic refrigeration to commercial refrigeration and air-conditioning to industrial refrigeration. However, it is desirable to minimize the charge to prevent toxic effects and, sometimes to use secondary refrigerants, such as volatile carbon dioxide, to keep ammonia away from the general public. This article describes a ...

We demonstrate highly transparent silicon-vanadium and silicon-aluminum tunnel junctions with relatively low sub-gap leakage current discuss how a trade-off typically encountered between transparency affects their refrigeration performance. theoretically investigate cascaded superconducting junction refrigerators two or more stages. In particular, we develop an approximate method that takes int...

In this study, the problem of a parallel connected power and absorption cooling cogeneration system was analyzed and then an improved configuration based on this system was proposed. This system can make cascade utilization of the turbine exhaust heat. By varying turbine outlet pressure, different turbine exhaust vapor temperatures can be obtained, resulting in different amounts of heat that ca...

The thermodynamic and thermo-economics models for three-pressure absorption-ejector hybrid refrigeration system are set up. The thermo-economical analysis model of the system is considered in two cases of high-temperature heat resources: waste heat resources and natural gas fuel are presented. The performances of the system in two modes of the running hours per year (600h and 1000h) are calcula...

This review discusses the progress and ongoing efforts in optical refrigeration. Optical refrigeration is a process in which phonons are removed from a solid by anti-Stokes fluorescence. The review first summarizes the history of optical refrigeration, noting the success in cooling rare-earth-doped solids to cryogenic temperatures. It then examines in detail a four-level model of rare-earth-bas...