Mechanical Engineers:Brian Church

Tyler Breitung Michael Oplinger

P15318 Gaseous Mass Flow Rate Controller

Electrical Engineers:Anthony Salmin

Ross Bluth Stephen Mroz

Sponsor: Dr. Roman Press (Alphacon LLC) Team Guide: Mr. Edward Hanzlik

Project BackgroundAs oil and gasoline prices continue to rise, along with their environmental concerns, the discovery of natural gas sources in the United States creates the opportunity to utilize natural gas as an alternative for transportation fuel. In order to harness the energy in compressed natural gas (CNG), a system that can precisely regulate and deliver the fuel to an internal combustion engine is needed. A current design, developed by Alphacon LLC, is able to regulate mass flow rate with an accuracy of ± 1 % of full scale and a response time of less than 70 ms. However, this device does not have its own dedicated controller and has no means of mixing the regulated fuel with air or delivering it for use in an internal combustion engine.

Problem Statement The primary objective of this project is to design a Gaseous Mass Flow Rate Controller (GMFRC) that improves on the current device by implementing a means of control and developing a means for mixing the regulated fuel with air and delivering it for use in an internal combustion engine. The GMFRC should utilize a control algorithm to increase the flow rate control accuracy and overall performance. The device should also be designed to be used in an automotive environment.

Most up to date engineering requirements

Problems Encountered• High operating pressures can overcome the spring force keeping the output port pressed up

against the rotating disk, which eventually causes separation and a significant leak.• Friction between the output port (delrin) and rotating disk (aluminum) slows down the

response time of the actuator.• The torque output of the actuator is highly non-linear and not the same when rotating it

forward and reverse , partially due to the torsion return spring in the actuator.• Noticeable leak when the valve is closed, even after lapping the mating surfaces.

Distribution Plate

Customer Requirements Engineering Requirements

Opportunities for Future Work• Explore a valve design that uses a cam and ball concept in place of the rotating disk to

reduce the leak when the valve is closed and sliding friction at the contact area.• Explore different motors that may be easier to control (stepper, servo, linear actuator). • Explore different control algorithms such as an analog PID.• Reduce the size of the electronics and incorporate them into one main housing.

Design Concept1. Control Disk2. Output Port3. Spring Seat4. Main Housing5. Compression Spring6. Rotary Actuator7. Position Sensor8. Bearing9. Input Fitting10. Output Fitting11. Actuator O-Ring12. Output Port O-Ring13. Tube Adaptor14. Tube Adaptor15. Cross16. Bushing17. Pressure Sensor18. Temperature Sensor

AcknowledgementsWe would like to thank our guide, Edward Hanzlik, for all of his help and support throughout the entire design process. We would also like to thank our customer, Dr. Roman Press, for his assistance with our system design, Dr. Lynn Fuller for his manufacturing services and assistance with our electrical hardware, and the Mechanical Engineering Machine Shop and Brinkman Lab staff for their assistance with machining our components.

Circuit Architecture Printed Circuit Board (PCB)

Preliminary EngineeringM – Mach NumberP – PressureR – Universal Gas Constant

T – TemperatureA – Valve Opening Areak – Specific Heat RatioPressure Drop (Bar)Temperature (°C) -40 -20 0 20 40

MASS FLOW RATE (g/s)0 0 0 0 0 01 2.19 2.28 2.37 2.45 2.532 4.37 4.55 4.73 4.9 5.073 6.56 6.83 7.1 7.35 7.64 8.74 9.11 9.46 9.8 10.135 10.93 11.39 11.83 12.25 12.676 13.11 13.66 14.19 14.7 15.27 15.3 15.94 16.56 17.16 17.738 17.48 18.22 18.93 19.61 20.269 19.67 20.5 21.29 22.06 22.810 21.85 22.77 23.66 24.51 25.33

4

Area of Valve Opening (mm2)