Energy Efficiency Suite vs PIDTune

This is a suite of twelve apps published already are put together to facilitate as a tool for performing energy efficiency studies especially in energy intensive chemical and process industries as well as HVAC applications. Hence, this can serve as an onsite analysis tool for energy engineers, auditors and technical personnel for assessing the energy saving potential. Further it can save more than 50% in total cost of individual apps. Apps can be grouped under three different categories such as supporting apps, device apps and energy cycle apps as given below. Supporting Apps: 1. Thermo-Physical Properties (16 common industrial fluids) 2. Fluid ΔP (Fluid pressure drops in pipes and conduits) 3. Orifice flow (Measurement of flow rates in pipes) 4. Engineering unit conversion (SI to USCS unit conversion) Device Apps: 1. Boiler Fuel Efficiency (with CHP) 2. Centrifugal Pump Specification 3. Fan Specification Performance 4. Compressor Capacity Performance 5. Heat Exchanger Performance Energy Cycles 1. Rankine Cycle 2. HVAC Cooling Cycle 3. HVAC Heating Cycle Users can save all their application data pertaining to energy cycles as well as major devices (Boiler, pump, heat exchanger and fan-duct system) in a file with unique title for reviewing and monitoring individual performance time to time. Users can use either SI and USCS units for both inputs and output. Please note that CHP (Brayton) cycle is part of BoilerFE app. The screen shots shown are mainly for energy cycle (Rankine and HVAC cooling cycles) apps. Therefore, please refer App stores for all other individual app descriptions and screen shots that were already published. Additional details are also available at our web site www.flowjoule.com/download.html This application suite has all the current updates with bug fixes for devices with iOS 14.. and higher and this will be frequently updated with added features time to time.

PID Tuner uses the IMC (Internal Model Control) method to calculate PID tuning parameters. I’ve tried a lot of tuning methods over the years and have found this one to be the best. The app is written for the iPad to show all the information on one page. The program calculates: PID Parameters: Controller Gain (Kc) Integral Time (Ti) Derivative Time (Td) For process types First Order with Dead Time (FO) Second Order with Dead Time (SO) Integrating or Long Time Constant with Dead Time (I) For controller types Parallel (non-interacting) c(s) = Kc (1 + 1/(Ti s) + Td s) Series (interacting) c(s) = Kc (Ti s + 1)/(Ti s)(Td s + 1) For controller modes PID PI You can either enter the process gain (Kp) directly or enter the changes in the controlled virable (CV) and manipulated variable (MV). Tuning aggression is adjusted using the slider to set the closed loop time constant to the process time constant ratio (λ/Ƭ). The closed loop time constant (λ) is the time the controller is expected to reach set point (plus the dead time (ϴ)). Setting the closed loop time constant to process time constant ratio (λ/Ƭ) to 1.0 will make the MV change to its final value and allow the process to settle out to the setpoint. Setting (λ/Ƭ) greater than 1.0 will give a slower responce. Setting (λ/Ƭ) less than 1.0 will cause the MV to make a larger change and then reduce to its final value. Tight tuning would be to set the close loop time constant to the dead time. Use the Integrating Process type (Ƭ = ∞) for both integrating processes or processes with long time constants. These processes use the maximum slope as the process gain. Tuning aggression for these processes is determined by setting the closed loop time constant to the dead time ratio (λ/ϴ). Once again, setting the closed loop time constat to the dead time gives tight control. References: “Probably the test simple PID tuning rules in the World,” Sigurd Skogestad, Jounal of Process Control, July 3, 2001 “Consider the generalized IMC-PID method for PID controller tuning of time-delay processes,” Y. Lee, S. Park, M. Lee, Hydrocarbon Processing, January 2006