Valve constant

Change the valve constants and note the influence on the dynamics. 

A liquid stream at a flow rate vi, is fed to the top of a vertical cylindrical container with cross-sectional area A. At the bottom of the container the liquid flows out of the container in a pipe through a valve at a flow rate = (AP/fc)° where AP is the pressure drop across the valve, and k is the valve constant. The container cross-sectional area, A = 9 m, and the liquid density, p = 1000 kg/m ... 

Figure 5.27 shows the effect of the valve constant (fe). By choosing the correct value a reasonably close match can be achieved to the output conditioning required (see Figure 5.25). 

Kp= first-order process static gain = first-order valve constant K = first-order measurement constant ItjS proportional gain for the three-mode controller f= Laplace transform of the output temperature deviation f = Laplace transform of the input load temperature deviation = first-order lime constants for the process, measurement device, and process valve, respectively. 

---