Leonard L. Vasiliev

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%.

Heat storage device for pre-heating internal combustion engines at start-up☆

Abstract The development of heat storage (HS) devices for pre-heating internal-combustion engines at start-up is presented as an extremely urgent problem. The absence of warm garages and the above-average depreciation of automotive machinery, especially urban buses, force maintenance organisations to search for new ways to facilitate engine start-up in cold periods. In this work, a thermal accumulator (HS) working on the effects of absorption and rejection of heat energy at the solid-liquid phase-change of the heat storage substance is discussed. In the theoretical part, a numerical method for calculating heat storage and the characteristics of heat storage devices is described. The experimental part describes the laboratory installation simulating conditions for the working of the HS device and presents the results of laboratory experiments. Data on full-scale tests of pre-heating devices for starting carburettor engines and an analysis of data received are given.

Intensification of heat transfer at propane pool boiling on single horizontal tubes

A set of experiments was carried out with propane pool boiling on the smooth and porous surfaces of horizontal tubes in the saturation pressure ranges p = 3.45 to 13.8 bar (ppc = 0.081 to 0.323), temperature intervals − 10 to + 40 °C, and heat flux ranges 102 to 105 W·m−2. Three modes of heat transfer were determined: free convection, a transitional mode and developed boiling. Good correlation between the experimental data on smooth tubes and the data published in other references was observed. The dependence of boiling process on saturation pressure and the influence of porous coating parameters on heat transfer intensity were studied. Samples of smooth tubes, tubes with small roughness and tubes with gas-thermal metal sintering on the surface were used for the experiments. Remarkable heat transfer enhancement of up to 2.5–3 times was observed for propane pool boiling on porous horizontal tubes, in comparison with that on smooth and small roughness tubes over the heat flux intervals tested.

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.