卷 53, 编号 11-12 (2018)

The possibilities of reducing the temperature of the heat transferring wall by intensifying heat transfer in productive tubes of viscous liquid heaters to reduce the risk of tube coking are analyzed. A generalized relationship linking thermal and hydraulic properties of flows at low Reynolds numbers is derived for heat transfer intensifiers in the form of wire spirals and twisted tapes inserted into the tubes. It is shown that the design specifications of the heat transfer intensifiers, which ensure the desired level of heat-transferring wall temperature reduction, can be determined by the derived relationship.

A mathematical description of heat transfer is presented and a procedure is developed for calculating the temperature characteristics of electro-ultrafiltration process for separating industrial solutions in flatchamber type of apparatuses. The permeate and retentate temperatures, solution heating temperature, heating power, and amount of heat liberated in the process of separation of industrial solutions and effluents containing anionic surfactants, proteins, and phosphatic and biochemical substances are calculated by the developed procedure.

It is shown that the additional turbulence of the flow in the processes of electric desalting of oil will substantially intensify existing technologies. Turbulence facilitates the mixing of the emulsion, the convergence of droplets and increases the probability of merging of droplets. The electric field contributes not only to the convergence of droplets, but also to the destruction of adsorption films around the drops. Therefore, combining the treatment of an emulsion in an electric field with a turbulent regime of its motion leads to a sharp improvement in the quality of oil demulsification. It is concluded that in order to find the optimal parameters for the operation of industrial devices, a theory is needed that, in addition to the droplet motion mechanism in turbulent vortices, also describes deformation of droplets, as well as the processes of destruction and the confluence of droplets. For studying the processes of changes in the topography of heterogeneous systems and the diagnosis of turbulent flows, the most promising is the numerical method for modeling the structure of flows.

The effect of electric field nonuniformity on the processes of creation and destruction of water-oil emulsions during crude oil desalting was investigated. It is shown that electrodemulsification of crude oil in a uniform electric field is ineffective. To increase the efficiency of electro-desalination, it is proposed to provide in the apparatus three contact stages with various hydrodynamics of the emulsion flow and electric field strength. It is suggested to place electrodes in the horizontal body of the apparatus. For this, one electrode is executed in the form of vertical injectors for “dry” and/or initial emulsion, and the second – in the form of a flat Venturi channel. Any productivity can be achieved by increasing the length of the apparatus, and electric field nonuniformity and strength adjustments make it possible to obtain three stages of separation of the emulsion.

The use of the Lorenz cycle together with the inverse Carnot cycle increases the conversion efficiency of a heat pump by 25–30%. The Lorenz cycle may be implemented either through the use of nonazeatropic substances or by multistage circuits. The Lorenz cycle is more efficient at low temperature differences of the working substances.

Special features of the kinematics of large-diameter multiple rolling-cutter rock drilling bits under the conditions of reactive turbo-drilling are considered. An analysis of the kinematics of the rolling cutters of drilling bits functioning with slippage of the cutting structures along the well bottom is undertaken. Factors that influence the magnitude and direction of slippage of the teeth of the cutting structures along the well bottom are determined. Shortcomings of the geometry of the cutting structures of rolling-cutter drilling bits designed for full-diameter drilling when used in reactive turbo-drilling units are identified. On the basis of these studies, it is concluded that fabrication of drilling bits of increased diameter with the use of sections of standard box-type drills is not an efficient approach for full-diameter drilling, since the geometry of the cutting structures of conventional drilling bits does not take into account the specific features that arise in the interaction of the teeth of the cutting structures with the well bottom surface under the conditions of reactive turbo-drilling.

Results are given for a study of electrolytic boriding of components made of different grades of steel (steels 20, 40Kh, and 50), and boriding technology, results of metallographic and x-ray structural analyses, and a study of the quantitative change in FeB and Fe₂B phases through the depth of a diffusion layer is provided. Comparative results of research show the operating properties after various forms of chemical heat treatment and heat treatment.

A new method of convective drying of mineral oils using high-speed jet devices is proposed. In contrast to those known earlier, it provides active hydrodynamic phase contact conditions, and reduces the required process time from several scores of minutes to 3–5 seconds. The device used is simple and compact. The jet-type drier with a delivery of up to 0.6 m³/h has passed laboratory tests successfully.

The article deals with the investigation of the ethylene-butane natural gases mixture that is promising for practical application. A unit with a small volume cell created to obtain data on phase equilibria and thermal properties of binary mixtures of little investigated and rare substances using several experimental methods was presented. It is shown that it was possible to use non-standard measuring equipment to obtain sufficiently reliable results in a wide range of temperatures, pressures and compositions. Application of a new method to determine two-component gas mixtures concentration was demonstrated. The method of experimentation was described as well. The experimental results of ethylene–butane mixture thermal properties and vapor-liquid equilibrium that have expanded our knowledge in relation to this two-component natural refrigerant behavior in the low-temperature region and at high dilutions were tabulated. The comparison of the experimental and calculated data showed the possibility of applying the three-parameter cubic equation of state to simulate the thermodynamic properties of the ethylene–butane mixture without using test data of the mixture.

A relationship that establishes a correlation between the isentropic efficiency and volumetric efficiency of a piston compressor and that takes into account the dead volume, engine pressure ratio, and the state of the working body at the start of the compression process and its adiabatic index is obtained. With a pressure ratio greater than 3–4, the isentropic efficiency will be 3–12% higher than the volumetric efficiency.

Features of dissolved oil-product adsorption from industrial wastewater by a modified hydrophobic carbonate sludge are studied. The adsorption isotherm is obtained. The adsorption mechanism on the new sorbent is investigated as physical unactivated adsorption using thermodynamic and kinetic parameters. The Gibbs free energy (–(20.26–21.46) kJ/mol), isosteric heat of adsorption (0.9–1.17 kJ/mol), adsorption rate constants ((0.2–0.47)·10^–3sec^–1), and apparent activation energy (6.6–28.6 kJ/mol) are calculated. Adsorption under dynamic conditions is studied.

Results from studies of the removal from storage and solidification of low- and intermediate-level liquid radioactive waste in inorganic binders (cementation) are presented. Cavitation technology for recycling radiochemical wastes from nuclear power plant decommissioning increases the extraction throughput and strength of the cement compound.

Results are given for a study of the corrosion resistance of a number of protective coatings for offshore structures and shelf zone constructions operating under conditions of total and periodic immersion in sea water.