Standard Flow Compensation Question

[MER21]

Can someone explain why the design and actual MWs are inverted on standard flow compensation? Everything appears to work out fine for volumetric and mass flow compensation, but my actual and design MWs are inverted for standard mass flow compensation. Consider the following:


P/ρ = Z*(1545/MW)*T or ρ ∝ (P*MW)/(Z*T)


Q_meas = K * (√ΔP/√ρ_des) and m_meas = K * (√ΔP*√ρ_des)

meas = measured, des = design conditions, act = actual conditions


Volumetric Flow Compensation

Q_act = K * (√ΔP/√ρ_des) * (√ρ_des/√ρ_act), or

Q_act = Q_meas * √(P_des/P_act) * √(MW_des/MW_act)*√(Z_act/Z_des)*√(T_act/T_des)


Mass Flow Compensation

m_act = K * (√ΔP * √ρ_des) * (√ρ_act/√ρ_des), or

m_act = m_meas * √(P_act/P_des) * √(MW_act/MW_des)*√(Z_des/Z_act)*√(T_des/T_act)


Standard Flow Compensation

Qs_meas = Q_meas * (ρ_des/ρ_std) = K * (√ΔP/√ρ_des)*(ρ_des/ρ_std) =K* (√ΔP * √ρ_des)/ρ_std, or

Qs_act = K* (√ΔP * √ρ_des)/ρ_std * (√ρ_act/√ρ_des) = Qs_meas * (√ρ_act/√ρ_des), or

Qs_act = Qs_meas * √(P_act/P_des) * √(MW_act/MW_des)*√(Z_des/Z_act)*√(T_des/T_act)

But the formula for standard flow compensation uses √(MW_des/MW_act) - why?

 

[rotw]

Post deleted...Sorry. Prefer to exercise caution and see what experts have to say.