Thermo-Physical Properties

R. D. McCarty, Interactive FORTRAN Programs for Micro Computers to Calculate the Thermo Physical Properties of Twelve Fluids [MIPROPS], NBS Technical... 

Volumetric equations of state (EoS) are employed for the calculation offluid phase equilibrium and thermo-physical properties required in the design of processes involving non-ideal fluid mixtures in the oil, gas and chemical industries. Mathematically, a volumetric EoS expresses the relationship among pressure, volume, temperature, and composition for a fluid mixture. The next equation gives the Peng-Robinson equation of state, which is perhaps the most widely used EoS in industrial practice (Peng and Robinson, 1976). 

Thu K, Chakraborty A, Saha BB, Ng KC. Thermo-physical properties of silica gel for adsorption desalination cycle. Applied Thermal Engineering (in pres). 

Conventional methods for solving the coupled set of describing equations and thermo-physical property models are characterized by taking the primitive variables, or some subset of them, as the main iteration variables, and by working with the equations in essentially their "primitive" forms. Many methods have been proposed which may be regarded as conventional methods in this sense. For purposes of this paper, it is convenient to consider all conventional methods as members of one of two classes based on two fundamentally different approaches. 

Class II Methods. The methods of Class II are those that use the simultaneous Newton-Raphson approach, in which all the equations are linearized by a first order Taylor series expansion about some estimate of the primitive variables. In its most general form, this expansion includes terms arising from the dependence of the thermo-physical property models on the primitive variables. The resulting system of linear equations is solved for a set of iteration variable corrections, which are then applied to obtain a new estimate. This procedure is repeated until the magnitudes of the corrections are sufficiently small. 

Thermo-physical property models taken from Sanderson and Chien (29). 

Note Sanderson and Chien (22) reported 10 outside loop iterations using their conventional algorithm for the same system at the same pressure, but with T specified as 358 K. The number of inside loop iterations was not given. It is notable that each inside loop iteration of their algorithm requires that properties be calculated using the actual thermo-physical property models. 

Other thermo physical properties (Chap. 6-9) crystalline melting temperature... 

The thermo-physical properties of both gas and particles are constant. 

This Is a liquid-phase catalytic reaction system and the reaction conditions are very close to the critical conditions of the reactants propylene and benzene. The values of the thermo-physical properties (e.g., heat of formation and heat capacity) are generally not available at the reaction conditions and are difficult to evaluate accurately. We evaluated how well the thermophysical properties were estimated by simulating a commercial cumene reactor, and comparing the adiabatic temperature rise of the simulation with that of the observed data available. 

Following this analysis Q depends on two eapillary structure parameters - the mean hydraulic pore diameter and the inner diameter of the porous wick. To find the Qmax we need equation (3.9) analyze for the extreme function finding. Due to the temperature dependenee of the thermo-physical properties of the working fluid the maximum heat flow Q ,ax will be different for different saturated vapor temperatures Tsat in the heat pipe transport zone. Figure 8. For different angles of heat pipe inelination to the horizon we need to determine Qmax at the worst situation with the point of view of the heat transfer, when the heat pipe evaporator is above the heat pipe eondenser, vertieal (inverted) heat pipe disposition. 

In addition to MeABP and the pseudo-critical properties (T , P ), MW and the pseudo-acentric factor (to) are also required for estimating various thermo-physical properties of crude and its fractions. Several correlations/methods exist for calculating... 

Enthalpy is one of the most important thermo-physical properties required for calculating heat loads in process design. The most common models used for estimating enthalpies of petroleum and its fractions in the refining industry are based on the corresponding-states approach. Methods for calculating the necessary critical properties... 

Further, molecular simulation and computational chemistry have evolved, and are evolving, into important tools for developing better characterization techniques where it is not possible to measure all data. Even so, it is precisely the molecular complexity of petroleum fluids that seems to be an inhibiting factor in the use of these methods for developing better characterization methods. However, identification of important functional groups in petroleum fluids applying molecular simulation and/or computational chemistry for use with group contribution methods to predict thermo-physical properties may be an area for further research. 

The location of the maximum rate of NEB with respect to RH depends on the storage conditions (temperature, RH), on the thermo-physical properties... 

Effect of thermostabilizers on the polymer properties was studied by different physicochemical methods. For example, in the work [260] method of DSS (differential spectroscopy) was used to define the effect of polyester-imide on thermo-physical properties of PETP. By this method it was found out that polyester-imide reduces PETP ability to crystallization. Methods of thermogravimetric analysis (TGA) and infrared spectroscopy in the nitrogen atmosphere were used in the work [261] to define thermal stability of the mixture of PETP and polyamide with the additive - modifier - polyethylene. It has been found that introduction of the additive decreases activation energy which positively tells on the ability of PETP to thermal destruction. 

Carbon-carbon composites made with the functionally graded fiber arrangement technique present the opportunity to tailor thermo-physical properties into carbon materials. In this paper, the changing of the fiber architecture is the method for FGM. Fibers or matrices are other options for FGM. This functionally graded fiber arrangement technique can be applied to a wide range of materials processing. 

J. Gosse, The Thermo-Physical Properties of Fluids on Liquid-Vapor Equilibrium An Aid to the Choice of Working Fluids for Heat Pipes, Proc. 6th Int. Heat Pipe Conf., Grenoble, France, pp. 17-21,1987. 

The main sources of information of thermo-physical properties are listed below ... 

B. Sharma, Study on some thermo-physical properties in Li20-Zn0-SiC>2 glass-ceramics. Material Letters, 58, 2423-28(2004)... 

Values extracted and in some cases rounded off from those cited in Rabinovich (ed,), Thermo physical Properties of Neon, Argon, Krypton and Xenon, Standards Press, Moscow, 1976, This source contains values for the compressed state for pressures up to 1000 bar, etc, t = triple point. Above the solid line the condensed phase is solid below it, it is liquid. The notation 5,646,-4 signifies 5,646 x lO"", At 83,8 K, the viscosity of the saturated liquid is 2,93 x 10" Pa S = 0.000293 Ns/m. This book was published in English translation by Hemisphere, New York, 1988 (604 pp,),... 

Samuilov, E.V (1973), Thermo-Physical Properties of Gases, Nauka (Science), Moscow, p. 153. 

The system of equations (21.19)-(21.21) is solved numerically. As a result, the changes in time of water and methanol concentrations in a drop, temperature and radius of drops are determined. Thermo-physical properties of gas and liquid phases involved in equations can be determined by methods given in [9]. Calculations were carried out for various pressures, initial temperatures of the drop and gas, and initial concentrations of methanol in the inhibitor solution. The composition of gas used in calculations depends on p, T and should be determined in advance from the equations of vapor-liquid equilibrium. Thus, for p = 8 MPa and T = 313 °K, the following composition is obtained (molar fractions) N2 = 0.81 CO2 = 0.22 CH4 = 96.97 CzHg = 1.74 CjHg = 0.16 i - C4 = 0.07 n - C4 = 0.03. 

Ramanaiah, K., Prasad, A. V. R., Reddy K. H. C. (2013). Mechanical and thermo-physical properties of fish tail palm tree natural fiber-reinforced polyester composites, Int. L Poivm. Anal Charact. 18(2), 126-136. 

Much of the research activity in this area has related to heat transfer to inelastic non-Newtonian fluids in laminar flow in circular and non-circular ducts. In recent years, some consideration has also been given to heat transfer to/from non-Newtonian fluids in vessels fitted with coils and jackets, but little information is available on the operation of heat exchange equipment with non-Newtonian fluids. Consequently, this chapter is concerned mainly with the prediction of heat transfer rates for flow in circular tubes. Heat transfer in external (boundary layer) flows is discussed in Chapter 7, whereas the cooling/heating of non-Newtonian fluids in stirred vessels is dealt with in Chapter 8. First of all, however, the thermo-physical properties of the commonly used non-Newtonian materials will be described. 

The most important thermo-physical properties of non-Newtonian fluids are thermal conductivity, density, specific heat, surface tension and coefficient of thermal expansion. While the first three characteristics enter into virtually all heat transfer calculations, siuface tension often exerts a strong influence on boiling heat transfer and bubble dynamics in non-Newtonian fluids, as seen in Chapter 5. Likewise, the coefficient of thermal expansion is important in heat transfer by free convection. 

The thermo-physical properties including the effective viscosity are evaluated at the wall conditions of shear rate and temperature. For a power-law fluid therefore the effective viscosity is evaluated at the shear rate of (3n -I- l)/4n (8V/Z)). However, Oliver and Jenson [1964] foimd that equation (6.37) imderpredicted their results on heat transfer to carbopol solutions in 37 mm diameter tubes and that there was no effect of the (L/D) ratio. They correlated their results as (0.24 [Pg.273]

The theoretical treatments considered so far have been based on the assumption that the thermo-physical properties are constant (i.e. independent of temperature and therefore the velocity profiles do not change over the heat transfer section of the tube. Christiansen and Craig [1962] investigated the effect of temperature-dependent power-law viscosity on the mean values of Nusselt number for streamline flow in tubes with constant wall temperature. They postulated that the flow behaviour index, n was constant and that the variation of the consistency coefficient, m, with temperature could be represented by equation (6.45) giving ... 

A coal-in-oil slurry which behaves as a power-law fluid is to be heated in a double-pipe heat exchanger with steam condensing on the annulus side. The inlet and outlet bulk temperatures of the slurry are 291 K and 308 K respectively. The heating section (inner copper tube of 40 mm inside diameter) is 3 m long and is preceded by a section sufficiently long for the velocity profile to be fully estabhshed. The flow rate of the slurry is 400kg/h and its thermo-physical properties are as follows density = 900 kg/m heat capacity = 2800 J/kg K thermal conductivity = 0.75 W/mK. In the temperature interval 293 < T < 368 K, the flow behaviour index is nearly constant and is equal to 0.52. 

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