Considerations about equations for steady state flow in natural gas pipelines

Abstract

In this work a discussion on the particularities of the pressure drop equations being used in the design of natural gas pipelines will be carried out. Several versions are presented according to the different flow regimes under consideration and through the presentation of these equations the basic physical support for each one is discussed as well as their feasibility.

Influence of Friction Factor and Flow Equation on Calculation of Gas-Distribution Pipeline Networks

“…The total network gas supply input in node 1 is 2339.4 m 3 /h. Calculation is done according to original Hardy Cross (1936) method, improved Hardy Cross method, both with Schifrinson (1937) and Renoard (1962) friction factor (Coelho and Pinho, 2007). Relation for corrections used in Hardy Cross method (19) is done based on relation (2) showed also in the paper of Manojlović et al, (1994), and here presented relation (18).…”

“…11) cannot be used, here can be recommended some of the relations correlated to line B in fig 1 and 2. These equations are (5), (7) and (8).Especially, Renouard (1962) equations are frequently used in Serbia, France, Portugal (Coelho and Pinho, 2007), Spain and many other countries for the sizing of distribution gas lines. Today, polyethylene pipes (von Bernuth and Wilson) are used for construction of gas distribution networks, and these pipes are approximately smooth.…”

“…Now, friction factor-λ, can be replaced with Renouard relation (8), and after transformation -see details in the papers of Renouard (1962) and Coelho and Pinho (2007), final equation can be written as (18): -5 m 2 /s, and a flow temperature of 15 ºC. This means that by fixing the value of gas cinematic viscosity, the density is also kept fixed, which is physically inaccurate when considering compressible gas flows at medium or high pressure, because the cinematic viscosity of gases is highly dependent upon pressure.…”

The effect of hydrogen transported through gas pipelines on the performance of natural gas grid

“…The normal pressure is 101.325 kPA, the normal temperature is 273.15 K, the relative density of gas is the normal density of a given gas (for the analysed blend without hydrogen it is 0.738 kg/m 3 ) divided by the normal density of air (1.293 kg/m 3 ). The dynamic viscosity of gas is usually given as a constant, due to its small variations depending on pressure and temperature (the authors of the study [3] state that the typical constant is 1.0758·10 -5 Pa·s). It was decided, though, to take account of its variations, by computing its value through Lee-Gonzalez correlation [9].…”

Study on the Decompression Time of the Hypobaric Rapid Decompression Chamber

“…At the assumption that pressure balance is reached when the pressure difference is less than 500 Pa, the balance time is 336ms [12].…”