S. A. Burtsev

Study of the Influence of Dissipative Effects on the Temperature Stratification in Gas Flows (Review)

We review publications devoted to various types of gasdynamic energy separation. Processes occurring in a vortex tube, ejectors with a negative ejection factor, stratification in gas flows and flows around the walls, etc., are discussed. The data and information on the methods and methodologies allowing one to carry out investigations and/or estimations of the energy separation effect are presented. Particular attention is paid to the effect of gas dynamic temperature stratification.

Exploring ways to improve efficiency of gasdynamic energy separation

This work is devoted to research into ways to improve the efficiency of gasdynamic energy separation in the pipe Leontiev. It is shown that restoring the coefficient of temperature r depending on the Prandtl number Pr has the greatest impact on the magnitude of energy separation. The conducted analysis showed that for a gas with Pr = 0.7 the most promising ways to improve the efficiency of gasdynamic energy separation are the partial condensation of the working body and the use of regular relief that is deposited onto the wall of the supersonic channel in the pipe Leontiev. We have performed a modification of the calculation method and its verification using experimental data obtained on natural gas. The results of numerical modeling have shown that the use of regular relief (dimples) in this class of devices is effective.

Peculiarities of studying thermohydraulic characteristics of relief surfaces

The results of experimental study of the thermohydraulic characteristics of a relief surface covered with a vortex-forming relief (a massive of dimples) are presented. It has been shown that, when carrying out the experiments, the prehistory of the flow should be taken into account and that it is necessary to determine the heat exchange and friction parameters in a single experiment not only on the vortex-forming relief; i.e., it is necessary to carry out a comparative experiment by measuring the corresponding characteristics of a smooth surface.

A method for distributed production of liquefied natural gas at gas-distribution stations

The operating conditions of gas-distribution stations located on gas-main pipelines are analyzed. It is shown that there is a technological pressure difference in natural gas at most stations, which can be used for liquefaction of natural gases. The data of the numerical investigation, demonstrating that it is possible to abandon the use of flame heaters of reduced natural gas due to the use of the gasdynamic energy separation effect by simultaneously cooling the natural gas going to liquefaction, are given. This technique can be applied on a quarter of all gas-distribution stations of the Russian Federation (about 1000 stations).

Device for separation of vortex gas-dynamic energy

A device for separation of vortex gas-dynamic energy, which combines the mechanism of separation of vortex energy used in the Ranque–Hilsch tubes and the mechanism of separation of gas-dynamic energy, is proposed for supersonic flows. A method of calculation of this device is developed. A comparison is made that showed that, when working with natural gas, the cooling depth of half of the mass flow rate proves to be 1.3 times higher than that for the vortex tube and three times higher than that for the device for separation of the gas-dynamic energy.

Intensification of heat exchange in a device for gas-dynamic energy separation

The operating efficiency of a gas-dynamic energy-separation device is analyzed, and it is shown that it can be improved if we deposit a regular relief on the wall separating the supersonic and subsonic channels. To decrease the total pressure losses on the side of the supersonic channel, shallow spherical dimples (stampings) are deposited, creating spherical ledges in the subsonic channel because of the small thickness of the wall. The calculation technique is modernized, and modeling is carried out, which shows that by introducing intensified heat exchange, it is possible to improve the efficiency of this device by 1.2–1.4 times in air and in natural gas with a simultaneous decrease in the device size by 20–25%.

Cycle of a closed gas-turbine plant with a gas-dynamic energy-separation device

The efficiency of closed gas-turbine space-based plants is analyzed. The weight–size characteristics of closed gas-turbine plants are shown in many respects as determined by the refrigerator−radiator parameters. The scheme of closed gas-turbine plants with a gas-dynamic temperature-stratification device is proposed, and a calculation model is developed. This model shows that the cycle efficiency decreases by 2% in comparison with that of the closed gas-turbine plants operating by the traditional scheme with increasing temperature at the output from the refrigerator−radiator by 28 K and decreasing its area by 13.7%.