Search results
Results From The WOW.Com Content Network
The fundamental principle was suggested by P. Debye (1926) and W. Giauque (1927). [6] The first working magnetic refrigerators were constructed by several groups beginning in 1933. Magnetic refrigeration was the first method developed for cooling below about 0.3 K (the lowest temperature attainable before magnetic refrigeration, by pumping on 3
Below 10 K one uses magnetic materials which are specially developed for this application. The so-called coefficient of performance (COP; denoted ξ {\displaystyle \xi } ) of coolers is defined as the ratio between the cooling power Q ˙ L {\displaystyle {\dot {Q}}_{\text{L}}} and the compressor power P .
As a consequence of Faraday's law of induction, any loop of wire that generates a changing magnetic field in time, also generates an electric field. This process takes energy out of the wire through the electromotive force (EMF). EMF is defined as electromagnetic work done on a unit charge when it has traveled one round of a conductive loop.
A liquid (glycol based) chiller with an air cooled condenser on the rooftop of a medium size commercial building. In air conditioning systems, chilled coolant, usually chilled water mixed with ethylene glycol, from a chiller in an air conditioning or cooling plant is typically distributed to heat exchangers, or coils, in air handlers or other types of terminal devices which cool the air in ...
Because of increasing cost and the dwindling availability of liquid helium, many superconducting systems are cooled using two stage mechanical refrigeration. In general two types of mechanical cryocoolers are employed which have sufficient cooling power to maintain magnets below their critical temperature.
An active magnetic bearing works on the principle of electromagnetic suspension based on the induction of eddy currents in a rotating conductor. When an electrically conducting material is moving in a magnetic field , a current will be generated in the material that counters the change in the magnetic field (known as Lenz's Law ).
Commercial refrigeration. Refrigeration is any of various types of cooling of a space, substance, or system to lower and/or maintain its temperature below the ambient one (while the removed heat is ejected to a place of higher temperature). [1] [2] Refrigeration is an artificial, or human-made, cooling method. [1] [2]
The working fluid is 3 He, which is circulated by vacuum pumps at room temperature. The 3 He enters the cryostat at a pressure of a few hundred millibar . In the classic dilution refrigerator (known as a wet dilution refrigerator ), the 3 He is precooled and purified by liquid nitrogen at 77 K and a 4 He bath at 4.2 K.