Fluid flow device with sparse data surface-fit-based remote calibration system and method

A method for calibrating a product variable aperture fluid flow device disposed within a site duct defining a product fluid flow path though the site duct from an upstream end of the site duct to a downstream end of the site duct,

• wherein the product variable aperture fluid flow device includes a product structure characterized by a product geometric shape adapted for fluid flow therethrough along the product fluid flow path, and a set of product operational parameters,
• wherein the product variable aperture fluid flow device includes:
• (i) one or more product blades of a product damper assembly, a product actuator assembly, and an associated product blade controller, whereby the product blades are movable by the product actuator assembly in response to the product blade controller to define a product orifice extending transverse to the product fluid flow path and through an array of one or more adjustably sized cross-section area product apertures, wherein, in the aggregate, the product apertures, are adjustable between a lower limit and an upper limit and
• (ii) a product differential pressure sensor adapted to determine pressure drops ΔP across the respective product apertures,
• comprising the steps of:
• for a calibration variable aperture fluid flow device remote to the site duct and disposed within a calibration duct on a test stand, wherein the calibration duct is disposed about a calibration flow path, wherein the calibration duct has a calibration duct is characterized by substantially the same geometry as the product site duct, and wherein the calibration variable aperture fluid flow device is has a calibration structure characterized by a calibration geometric shape adapted for fluid flow therethrough along the calibration fluid flow path, and calibration operational parameters, which calibration geometric shape and calibration operational parameters are both substantially the same as the product geometric shape and product operational parameters of the product variable aperture fluid flow device,
• A. with a calibration controller controlling operation of the calibration variable aperture fluid flow device at the test stand,
• a. establishing a plurality of calibration conditions with respect to the calibration variable aperture fluid flow device, wherein each of the plurality of calibration conditions is represented by one of a set of calibration data trio's X-Y-Z space wherein each calibration data trio includes for a calibration condition associated with a calibration data point (x, y, z) in an X-Y-Z coordinate space:
• i. a calibration aperture area data element characterized by a calibration orifice area value X corresponding to an associated aggregate area Ao of a calibration orifice of the calibration variable aperture fluid flow device for the associated calibration condition,
• ii. a pressure drop data element characterized by a square root of pressure value Y corresponding to an associated pressure drop ΔP across the calibration orifice of the calibration variable aperture fluid flow device for the associated calibration condition, and
• iii. a CFM data element for the associated calibration condition, characterized by a calibration flow rate value Z, wherein Z is representative of fluid flow rate (CFM) through the calibration orifice of the calibration variable aperture fluid flow device when (1) the aggregate area Ao of the calibration orifice of the calibration variable aperture fluid flow device equals the aggregate area value X for the associated calibration condition, and (2) the square root of pressure drop ΔP across the orifice of the calibration variable aperture fluid flow device equals a pressure value Y for the associated calibration condition,
• whereby the establishment of the calibration data trio's for the plurality of calibration conditions effects a multiple discrete point calibration flow rate function where the multiple discrete point calibration flow rate function is a multiple discrete point function Z=f(X, Y) in the X-Y-Z space, comprising the plurality of discrete (X,Y,Z) points corresponding to the respective data element trio's for the respective calibration conditions, and is thereby associated with the values of the set of calibration data trio's whereby a CFM Function defines a CFM mathematical surface in the X-Y-Z space approximating a mathematical surface corresponding to f(x,y,z), in the X-Y-Z space which includes the discrete (x,y) data pairs and their respective associated z values, and points interpolated between those discrete points in X-Y-Z space,
• B. transferring CFM data representative of the CFM Function from the calibration variable aperture fluid flow valve to the product memory associated with the blade controller of the product variable aperture fluid flow device,
• C. storing the transferred CFM data in the product memory,
• D. by the product blade controller, for a succession of (x, y, z) data points:
• a. extracting from the stored CFM data representative of the CFM Function, data representative of the succession of (x, y, z) data points,
• b. for each (x, y, z) data point in the succession,
• i. applying the associated X value to the product actuator assembly to adjust the aggregate aperture area Ao of the orifice of the product variable aperture fluid flow device,
• ii. applying the associated Z value to adjust the fluid flow rate through the product variable aperture fluid flow device, and
• iii. in response to an applied parameter control signal representative of a desired value for a controlled parameter, in a closed loop manner, augmenting the Y value applied to the pressure sensor,
• whereby the adjustably sized cross-section area product flow apertures are adjusted over time so that advancement toward a set point for the controlled parameter is attained.