Leonid L. Vasiliev

Adsorbed natural gas storage and transportation vessels

Adsorbed natural gas (ANG) storage and transportation technology recently became competitive to compressed natural gas (CNG) method due to a high energy density capability achievements. New adsorbents such as monolithic carbons and recently compressed active carbon fibers used in noncylindrical vessels have made possible to store the same capacity of gas as CNG tanks, but at much lower pressure. New types of gas tanks thermal control systems with internal source of energy input, based on heat pipe heat exchangers, make it possible to use different sources of energy (exhausted gases, wasted engine cooling liquids, solar and other types of energy) to stimulate gas desorption at constant rate of gas delivery and constant pressure (temperature) and avoid the drop of temperature in the storage tank due to the enthalpy of desorption.

A solar and electrical solid sorption refrigerator

Refrigeration technologies have been critical in the evolution of the production and distribution systems a long period of time. The concept of solar-powered refrigeration cycles is known at least two decades and several refrigerators operating on this principle are commercially available. Cohen and Cosar [1], have analyzed solar powered refrigeration. Guilleminot [2] demonstrated solar sorption refrigeration with cycle day/night to produce the ice using solar energy. Solar cooling processes using chemical reactions, Speidel and Kleinemeier [3], realized the cycle day/night. Bougard and Veronikis [4] used ammonia/active carbon in solar refrigerator. Wang [5] suggested a new hybrid system of solar powered water heater and adsorption icemaker. However, there has been a little research into the integration of short time cycles sorption machines of solar power with natural gas [6], or solar power with electrical immersion heater as a back up [7], Use of methane as an alternative heating system would be more economical and application of solar power simultaneously would reduce the cost and size of solar collectors. Actually two different solid sorption refrigeration cycles are mostly used-adsorption and chemical reaction [8], [9], [10], [11]. The combined action of physical adsorption and chemical reactions for the cold production in the same space and at the same time is attractive initiative to enhance the COP of a system [12]. Vasiliev [13] and Critoph [14] mentioned the use of heat pipes to improve the performance of carbon-ammonia adsorption refrigerator. It was shown that heat transfer within an active carbon sorbent bed could be improved dramatically by the use of finned heat pipe. Solar-guided sorption cycles can be also used in heat — driven refrigerators, or heat pumps in which the energy source is a burning fuel, or waste heat [15]. The concept aim of such research program is to extract the most enthalpy from the low-grade heat before it is purged into the surrounding. It is easy to perform, if an autonomous low pressure ANG vessels are used together with gas burner [16] and the energy of the waste gas is used to heat the low temperature sorbent bed. A solar-gas refrigerator based on a reversible solid sorption phenomena is competitive, if the process allow to store the energy of a high density, and if the heating, or cooling power is enough for consumers. Spinner [17] performed some theoretical research in this field. Castaing-Lasvignottes and Neveu [18] demonstrated the application of the first and second law of thermodynamics in equivalent Carnot cycle concept applied to thermo chemical solid/gas resorption system. Regarding the developing countries application there is a well-documented need for food refrigeration, air-conditioning in areas that do not have access to grid electricity. Spoilage of many products, particularly fish, can be as high as 50%.

Sorption Heat Pipe —A New Thermal Control Device for Space Applications

Sorption heat pipe is a novelty and combines the enhanced heat and mass transfer typical for conventional heat pipe with sorption phenomena in a sorbent structure. Sorption heat pipe can be used as a heat source / sink and be applied as a heat pipe. Sorption heat pipe is insensitive to some “g” acceleration and it is suggested for space and ground application.