Refrigeration, metal hydride

Hydrogen-storage alloys (18,19) are commercially available from several companies in the United States, Japan, and Europe. A commercial use has been developed in rechargeable nickel—metal hydride batteries which are superior to nickel—cadmium batteries by virtue of improved capacity and elimination of the toxic metal cadmium (see BATTERIES, SECONDARYCELLS-ALKALINe). Other uses are expected to develop in nonpolluting internal combustion engines and fuel cells (qv), heat pumps and refrigerators, and electric utility peak-load shaving. 

An explosion of 1 gm of a hydride thus named, but without more definite identification, during storage in a refrigerator is reported. Such a species might very well evolve either carbon monoxide, or hydrogen, in storage, pressurising its container. See other CARBONYLMETALS, METAL HYDRIDES... 

Application of hydride heat machines (the HHM - the hydride heat pump (HHP), a refrigerator, a heat transformer, the compressor, the accumulator of hydrogen) is justified there where there are sources of low-potential energy or a plenty of wasted heat is not used. Systems hydrogen-metal hydrides promote improvement of ecological conditions and introduction of cleaner hydrogen technologies. 

Shanin, Yu.I. (2002) Simulation of hydride heat pump operation with reference to vehicle refrigerating devices. - In Veziroglu TN, Zaginaichenko SY, Schur DV, Trefllov VI editors/Hydrogen Materials Science and Chemistry of Metal Hydrides. NATO science series. Series II Mathematics, Physics and Chemistry, 82, 97-106. 

Astahov, B.A., Afanasjev, V.A., Bokalo, S.J., et al. (1999) Creation of smallsized refrigerating installations with a metal hydride heat pump. - 6th NATO Int. Conf. Hydrogen Material Science and Chemistry of Metal Hydrides ", ICHMS 99. Abstract Book of NATO International Conference. Katsiveli, Yalta, Ukraine, September 02-08, 1999, 306-307 (in English and Russian). 

In other work cyclic operation of a metal hydride refrigerator [3] was analyzed. With the help of mathematical model for calculation of transfer processes to HHP the algorithm of definition of optimum switching of heat flows in system has been developed at given cycle time. The algorithm is constructed from a condition of achievement of the maximal refrigerating effect (real COP) on unit of brought heat. 

Figure 4.23 The metal hydride refrigeration system schematic (Qin et al.,2007).

Qin, F., Chen, J., Lu, M., Chen, Z., Zhou, Y. and Yang, K. (2007). Development of a metal hydride refrigeration system as an exhaust-gas driven automobile air conditioner. 

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