The Pacific Northwest is home to The Boeing Company and as such, the first flight of any new aircraft is big news.
When the 787 Dreamliner made its first flight, the two test pilots stated, “The airplane flies beautifully, it did exactly as we expected. No surprises and no major issues with the airplane.”
Prior to conducting the first actual flight, the test pilots “learned to fly the aircraft” using a flight simulator and will do this before any inaugural flight. These simulators have all the flight characteristics of the 787 Dreamliner in the program, which is how the test pilots knew what to expect on the first flight. Flight simulators range from multi-million dollar three axis flight simulator to flight simulator programs for use on PC’s.
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| Boeing 787 Dreamliner Flight Simulator - image courtesy The Boeing Company boeing.com |
One of the things I like best about my job is the ability to visit customers to see how they are using PIPE-FLO. The majority of our customers use PIPE-FLO to perform the preliminary design of their piping systems, specifically to obtain the design data needed for equipment selection. More recently though, I’ve been learning that more of our customers are entering increasingly detailed design data for their completed systems into their PIPE-FLO models. This provides them a better understanding of how the finished design will operate once it is placed in service.
For example, one of our long time PIPE-FLO customers needed to add cooling loads to a large cooling water system in their chemical process plant in Houston, Texas. The system was previously modeled using PIPE-FLO to determine if a new pump was needed for the proposed expansion. Once the system was modeled in PIPE-FLO, they determined that the existing pumps could meet the projected needs.
As the design became finalized, the PIPE-FLO model was updated with the design changes of the expanded cooling water system. After conducting a simulation, they were able to determine the valve positions of all the throttle valves. This was accomplished by entering the Cv characteristics of each throttle valve in the system into their PIPE-FLO model. Once this was done, PIPE-FLO calculated the valve position and identified that cavitation would occur in two of the control valves. Once the problem was identified in the simulation, the valve supplier was called in to see what could be done to correct the problem. The valve supplier suggested changing out the cavitating control valves with a different design. The model was updated with the new valve characteristics and the problem was solved. All this was done well before commissioning the expanded system.
When it came time to start up the expanded cooling water system, all the control valves were set to their calculated balanced valve position and the system was brought online. The client stated that normally it took an outside contractor two to three days to balance the cooling water system by manually adjusting things after taking readings. Using the valve positions calculated in the PIPE-FLO simulation, it only took half a day to validate that the system was balanced. Additionally, it was confirmed that no cavitation occurs in any of the control valves.
One of PIPE-FLO’s unique features is the used of manufacturers’ electronic pump catalogs. Using the same electronic pump catalogs the manufacturers use to pick a pump for customers, you are able to insert the pump into the piping system model to gain an accurate simulation. Once again the PIPE-FLO uses the methodology outlined in a variety of Hydraulic Institute standards for pump operation.
Finally, flow elements such as orifices, nozzles and venturi types are accurately modeled based on the applicable ASME and ISA standards.
During the simulation, all the information is factored into the total calculations. For example if during the simulation the user changes the temperature of the process fluid the program:
- Looks up the fluid properties of density, viscosity, and vapor pressure and use this information in all calculations.
- Calculates the head loss in all the pipelines affecting the pressures throughout the system.
- The change if the fluids vapor pressure and head loss in the suction pipeline affect the NPSH available at the pump suction.
- The vapor pressure also affects the cavitation calculations for control valves, flow meters, and pressure calculations throughout the system.
I would be hard pressed to say that a PIPE-FLO simulation has as much entertainment value as a flight simulator program, knowing how much I love flying aircraft, but it can show you a clear picture of how your piping system operates. And that type of solid reassurance and validation is exactly what you need before you take a multi-million dollar system online for the first time. Leaving you to say on your inaugural start-up, “The system runs beautifully, it did exactly as we expected. No surprises and no major issues with this piping system!”
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