RECALCULATION METHOD OF THE CHARACTERISTICS OF STRAIGHT-FLOW TUBULAR POROUS STEAM GENERATORS FROM BOUNDARY CONDITIONS OF THE SECOND KIND FOR BOUNDARY CONDITIONS OF THE THIRD KIND
Anatoly P. Lukisha
The article is devoted to the development of a method for recalculating the thermo-hydraulic characteristics of porous straight-through steam-generating channels from boundary conditions of the second kind to boundary conditions of the third kind. The need for the development of such recalculation procedure is due to the presence in the literature of calculated dependences describing the heat transfer during evaporation of the coolant in porous channel for boundary conditions of the second kind, while the practical plan problems are often conditioned by other boundary conditions, in particular boundary conditions of the third kind. The ultimate goal of the recalculation method was to create a program for calculating the thermo-hydraulic efficiency of porous straight-through steam generators. The proposed recalculation technique makes it possible to calculate, in the porous straightthrough steam generators, for boundary conditions of the third kind, such thermal-hydraulic characteristics as the length of the channel required for complete evaporation of the heat carrier; the power required to pumping the coolant in this case, and the total amount of heat transferred to the heat carrier during evaporation. To describe the calculation of the heat transfer during the evaporation of two-phase flows in porous materials, the experimental dependence obtained by I.V. Kalmykov, characterizing the intensity of volumetric intraporous heat exchange, depending on the regime parameters of the flow, was used. This universal experimental dependence is suitable for various types of porous materials. For calculating the hydraulic characteristics of a evaporating two-phase vaporliquid flow in a porous high thermo-conducting material was used adapted by Yu.A. Zeygarnik and I.V. Kalmykov experimental dependence that was founded on the Lockhart-Martinelli method for calculating the hydro-resistance of vapor-gas flows in porous media. The technique presented in the article makes it possible to calculate the thermal-hydraulic characteristics of porous straight-flow porous steam generators for boundary conditions of the third kind.
porous straight-through steam generators; recalculation of thermo-hydraulic characteristics from boundary conditions of the second kind to boundary conditions of the third kind
Kalmykov, I.V. Heat transfer and hydrodynamics at motion of the steam-liquid flow in porous media [Текст] : The dissertation on competition for the degree of candidate of technical sciences, / I.V. Kalmykov. – Мoscow, 1987. – 224 p. (rus.)
Poljaev, V.M. Hydrodynamics and heat transfer in porous design elements of aircraft [Текст] / V.M. Poljaev, V.A. Majorov, L.L. Vasiliev. – Мoscow: Mashinostroenije Press, 1988. – 168 p. (rus.)
Lukisha, A.P. Heat exchange at evaporating of flow in the cylindrical porous channel [Текст] / A.P. Lukisha // Visnyk Dnipropetrvskogo universitety. Ser.: mechanica. – Dnipropetrovsk, 2014. – Vol. 22. – № 3. – Iss. 16. – P. 107–114. (rus.)
Petuhov, B.S. Heat transfer and resistance at laminar flow of a liquid in pipes[Текст] / B.S. Petuhov. – Мoscow: Energija Press, 1967. – 411 p.(rus.).
Lockart, R.W. Proposed correlation of data for isothermal two-phase, two-component flow in pipes [Текст] / R.W. Lockart, R.C. Martinelli // Chemical Engineering Progress. – 1949. – Vol. 45(1). – P. 39–48.
Zeigarnik, Yu. A. Experimental study of the hydraulic resistance of porous structures at adiabatic motion steam-water mixture [Текст] / Yu.A. Zeigarnik, I.V. Kalmykov // Teplofizika vysokih temperature. – 1985. – Vol. 23. – № 5. – P. 934–940.(rus.)
Chisholm, D. Prediction of pressure gradient in pipeline system during two-phase flow [Текст] / D. Chisholm, L.A. Sutherland // Proc. Inst. Mech. Engrs, 1969. – Vol. 184. – Iss. 3 – P. 24–32.
Vargaftik, N. B. Handbook on thermophysical properties of gases and liquids / N. B. Vargaftik. – М.: Nauka, 1972. – 720 p.(rus.)