The effect of density, pressure drop, viscosity and orifice area on the characteristics of fluid flow was examined in this paper. Also studied was the effect on the control pressure change of the constant area variable pressure drop meter as a proportional derivative control. The mathematical model developed to monitor and predict the control of the system is given as P-Po = 7.8/t – 0.06 + Kc +Kd. The change in control pressure decreases with increase in proportional/derivative gain (Kc, Kd) as well as increase in time. The Bernoulli’s principle was applied in describing the design principle, stability analysis and development of mathematic model of a pressure-based flow meter with a constant area, variable pressure drop; using an orifice plate with different fluid flowing through it. The developed formula relates pressure drop with the flow rate of a given fluid passing through the orifice. The formula obtained is then simulated using different fluids. In order to control the flow rate, of these fluid flowing through the model developed was related to a Proportional Derivative control (PD). Thereby getting knowledge on how the PD controller performs with respect to different fluids, with change in pressure, density and area of the pipe/orifice was presented in this paper. Finally information and results on the simulation and how the PD controller functional parameters of proportional gain and derivative gain influence the control system was examined in this research.
CALCULATION METHODS OF VARIABLE PRESSURE-DROP FLOWMETERS ACCURACY IMPROVEMENT
