Mechanical Engineers: Brian Church Tyler Breitung

Michael Oplinger

Electrical Engineers: Anthony Salmin

Ross Bluth Stephen Mroz

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

Project Background

As 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 Concept 1. Control Disk 2. Output Port 3. Spring Seat 4. Main Housing 5. Compression Spring 6. Rotary Actuator 7. Position Sensor 8. Bearing 9. Input Fitting 10. Output Fitting 11. Actuator O-Ring 12. Output Port O-Ring 13. Tube Adaptor 14. Tube Adaptor 15. Cross 16. Bushing 17. Pressure Sensor 18. Temperature Sensor

Acknowledgements

We 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 Engineering M – Mach Number P – Pressure R – Universal Gas Constant

T – Temperature A – Valve Opening Area k – Specific Heat Ratio

Pressure Drop (Bar)

Temperature (°C) -40 -20 0 20 40

MASS FLOW RATE (g/s)

0 0 0 0 0 0

1 2.19 2.28 2.37 2.45 2.53

2 4.37 4.55 4.73 4.9 5.07

3 6.56 6.83 7.1 7.35 7.6

4 8.74 9.11 9.46 9.8 10.13

5 10.93 11.39 11.83 12.25 12.67

6 13.11 13.66 14.19 14.7 15.2

7 15.3 15.94 16.56 17.16 17.73

8 17.48 18.22 18.93 19.61 20.26

9 19.67 20.5 21.29 22.06 22.8

10 21.85 22.77 23.66 24.51 25.33

4

Area of Valve Opening (mm2)