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High Precision Equations of State

To improve the heat transfer conditions and to minimize the demands on the construction materials in a steam header, boiler feed water with Pbfw = 30 bar, i BFW = 150 C has to be injected into superheated steam (> ss = 20 t/h) with ilss = 400 C, P =20 bar to reduce the superheating to 5K. Determine the appropriate amount of boiler feed water.Use a high-precision equation of state (Appendix B) for the determination of the enthalpies, which should match the values obtained with the steam table [12 sufficiently well. [Pg.26]

The more difficult part is to set up a correlation for the residual part of the Helmholtz energy a (r, 5). For this purpose, a bank of terms that could be useful for a high-precision equation of state has been established (29]. The general setup for the fitting procedure contains 583 terms. It is expressed as... [Pg.35]

The high-precision equations of state refer only to pure components where chemical reactions are not involved therefore, the arbitrary choice to set them to 0 at standard conditions can be accepted. [Pg.35]

Using the high-precision equation of state, the density is calculated to be p = 410.5 kg/m. An experimental value of 410.839kg/m has been reported [40], indicating that the relative error is only 0.08%. Thus, the content is calculated to be 20.525 kg. [Pg.38]

Using a high-precision equation of state for water [20] in the FLUIDCAL system [41], the result is... [Pg.51]

The value obtained with a high-precision equation of state is p(300 K, 10 bar) = 20.06 kg/m This illustrates the extraordinary quality of the Peng-Robinson equation of state for nonpolar substances. [Pg.53]

With an adjusted c parameter, the deviations in the liquid density for Tr < 0.8 are in the range 1-2%. In the vicinity of the critical point Tr = 0.8. .. 1.0), larger errors are obtained, revealing a basic weakness in principle of cubic EOS. In process simulation, it should still be considered to override the results for the liquid density in the summary table with an appropriate correlation according to Section 3.2.2. For extreme pressures (e.g. >1000 bar), the application of a high-precision equation of state has to be preferred. [Pg.56]

A closed vessel is filled completely with liquid water at = 25 C, P] = 1 bar. Due to solar radiation, it is heated up to i>2 = 60 "C. Which pressure is built upi Use a high-precision equation of state. Calculate the transferred heat. [Pg.61]

A vessel is filled with nitrogen at =20 CandPi = 1 bar. With the help of a high precision equation of state,... [Pg.61]

However, it is recommended that predictions in this area should be taken more or less as a guess. For higher accuracy, high-precision equations of state (see Section 2.5.2) are recommended if available. [Pg.97]

Figure 3.11 Deviation plots for the enthalpy of vaporization of propane using the extended Watson equation and the PPDS equation. Reference data from high-precision equation of state [10]. Figure 3.11 Deviation plots for the enthalpy of vaporization of propane using the extended Watson equation and the PPDS equation. Reference data from high-precision equation of state [10].
The speed of sound plays an important role in the design of safety devices, as it determines the maximum possible flow rate of a fluid in case of a hazard. Furthermore, as a derivative property it has a considerable relevance for the adjustment of high-precision equations of state and for the indirect measurement of Cp, as explained in Section 3.2.4. [Pg.113]

Using these equations, the results for gases are usually sufficient. For liquids, a high-precision equation of state that describes the pressure-dependence of the liquid density is necessary. The expression for the speed of sound from high-precision equations of state formulated in terms of the Helmholtz energy (Eqs. (2.113) and (2.114)) is... [Pg.114]

For high-precision equations of state, there is currently no simple method available to apply them to mixtures where their advantages are maintained. For special mixtures such as natural gas, the development of a special equation has been considered to be useful [2]. For a few cases, the Lee-Kesler approach [3, 4],... [Pg.162]

In both cases, the compressor is fed with saturated vapor at i i = 10" C. Using a high-precision equation of state (Eq. (2.113)), we can calculate the state of the compressor outlet stream for thevapor pressure at 50 X. [Pg.598]

The mechanical efficiency is Jjmech = 0.95. Calculate the power of the compressor. The mass flow is 3000kg/h. Use a high-precision equation of state. [Pg.609]

P14.9 In an LDPE (Low Density Polyethylene) plant, ethylene is expanded from Po = 3000 bar. To = 600 K to Pi = 300 bar by a throttle valve. By a second throttle valve, it is expanded to environmental pressure P2 = 1 bar. Calculate the temperatures Ti and T2 by using a high-precision equation of state. The velocity terms in the First Law should be neglected. [Pg.609]

P14.ll A vessel (Im ) containing 500kg propylene at 1 = 30°C is exposed to sun radiation. What is the initial pressure The safety valves of the vessel actuate at P = 60 bar. Use a high-precision equation of state to calculate the respective temperature. [Pg.609]

I Appendix B Coefficients for High Precision Equations of State... [Pg.642]

In addition, models for special substances like carboxylic acids, hydrogen fluoride, formaldehyde, electrolytes, and polymers are introduced and the capabilities of high-precision equations of state and various predictive methods are explained. Recommendations for the parameter fitting procedure and numerous hints to avoid pitfalls during process simulation are given. Because of the space limitation in the book we were not able to cover the whole range of thermodynamics, for example, adsorption has been left out completely as it cannot be presented within a short chapter. [Pg.752]


See other pages where High Precision Equations of State is mentioned: [Pg.33]    [Pg.39]    [Pg.49]    [Pg.51]    [Pg.61]    [Pg.61]    [Pg.62]    [Pg.350]    [Pg.594]    [Pg.595]    [Pg.604]    [Pg.605]    [Pg.610]    [Pg.641]   
See also in sourсe #XX -- [ Pg.32 , Pg.33 , Pg.34 , Pg.35 , Pg.36 , Pg.37 , Pg.38 , Pg.641 , Pg.642 ]




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Coefficients for High Precision Equations of State

Equations high precision

High precision

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