Integrated System Build & Test
Table of Contents
February 28th - March 23rd, 2017
Team Vision for Integrated System Build & Test PhaseDuring this phase, our primary goal was to complete the list of test procedures we developed during the design phases of the project. This includes tests to validate our mathematical model for airflow through the system, verify the construction of our poppet valve assembly, and ensure the capability of our control and data acquisition system. Additionally, we planned to continuously develop our mounting arrangement of components for improved compactness, user friendliness, and reliability.
We were able to successfully characterize the flow of air through our system and verified our mathematical model as well as the sizing decisions made on all pneumatic fittings and valves. We also performed leak tests on our valve assembly showing zero leakage through our machined o-ring seals. Some leakage was found on pneumatic fittings which were solve with additional teflon tape and tightening. We also were able to construct a solid unit containing all electrical and pneumatic components in a compact footprint. This included custom made mounts to hold our valves with rubber for isolation. We also cut a plexiglass insert to hold the relays. This insert fits into the grooves of the 8020 frame. More parts were also ordered during this phase. We continued to update our documentation as we went through the process. An all-encompassing pressure test was also performed. We realized that we had the incorrect regulator valve so we placed an order for the correct one. We installed a pressure transducer on the backpressure tank as well. Progress was made on the technical paper and testing videos were uploaded to youtube. We received an accelerometer from Dr. Kolodziej and set up signal express to accept the signal from it. The poster for Imagine RIT was also started.
Test Results Summary
TestingTo date we have completed the following tests:
ER1 is the qualitative test to confirm the strength of our pressure vessel and its ability to handle the necessary air pressures required for functional testing as well as leak testing and validation of all other components. Initially, the test is completed on a the subsystem of just our pressure vessel and confirms its ability to hold full shop air pressure. Further testing found some small leaks in air fittings which were solved with additional sealant and tightening with no leaks in the valve manifold. We also were able to calibrate our pressure relief valve to a safe level ensuring no over pressurizing of the system without compromising the normal test sequence pressure ranges.
A video of leak testing can be found here.
A video of relief valve calibration can be found here.
ER2 tests the ability of our exhaust solenoid valve to vent the pressure vessel to atmosphere adequately fast for functional usage. The data from this test is used qualitatively against our flow model in the results analysis below. The same was done for the Intake Cycle.
A video of max air flow testing can be found here.
ER3 combines the ability of our solenoid valves to fill and release our system with air and begins the process of tuning for optimal poppet valve actuation and speed. The primary conclusion from this test was the failure of our watt's pressure regulator to control and maintain a specific air pressure in the back pressure tank. Further research indicates this is due to the valve being of the type for Water and for forward pressure regulating. The correct regulator must be determined and the current one must be returned as it was not labeled correctly through MSC's ordering catalog.
A video of functional air cycle testing can be seen here.
With the system setup as it will be during normal usage, we conducted two main tests:
One was to command the inlet valve to open and fill our pressure vessel from 0 PSI to 40 PSI.
The other was to, with the pressure vessel just above 40 PSI, command the exhaust valve to open and allow the pressure vessel to decompress to 0 PSI.
The data collected accurately indicates the required time for the pressure vessels intake and exhaust cycles. This data was then imported to Matlab to overlay on top of our theoretical model.
The raw data is seen here:
The resulting plot is shown here:
This indicated that our theoretical model was very accurate and useful in sizing the Intake and Exhaust valves as well as determining a minimum air fitting and hose inner diameter of 3/8".
Risk and Problem TrackingRisk Management can be found here. problem tracking can be found here.
Functional Demo Materials
The functional demo includes observing the full cycle pressure testing as seen in the above video from ER3.
Weekly progress reports between February 28th and March 23rd can be found here.
Plans for next phaseFor the next phase, we plan to install the correct pressure regulator to hold 40psi in the backpressure tank. We also plan to continue to update documentation such as the bill of materials and problem tracking. We plan to adjust the valve timing in order to more closely resemble the actual pressure curve of the Dresser-Rand compressor. We will continue to make progress on the paper and poster. We also need to machine a bracket to mount the correct pressure regulator.
The final testing required will be ER5 where installation and observance of an accelerator on the valve manifold will be done.