Foundation Coalition: Active/Cooperative Learning

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CNG Tank Design

A Freshman Engineering Design Project
Developed by Dr. Joey K. Parker, The University of Alabama

Instructions to Students

1.

Project Description

Your “client,” the local newspaper, has several contracted individuals that deliver their newspapers in rural areas. The new publisher believes that by operating several cars on natural gas, the paper can both save money and become more environmentally "friendly." The client will base their decision on a combination of:

estimated savings from lower fuel costs (simple payback period), and

your justification of any necessary assumptions.

2.

Design Goal

The design goal for this project is to select CNG tank size(s) for an automobile used to deliver newspapers along a rural route in Alabama. Specifically, select the inner and outer diameters and the length of the tank that will fit in the trunk of the team-selected automobile.

3.

Design Constraints from Client

Your client wishes to modify standard gasoline powered automobiles to operate on natural gas. Some of the client's constraints on your design are:

1.       entire paper delivery trip to be made using natural gas as a fuel (although the car will still have a gasoline supply for use in emergencies);

2.       re-fueling occurs only once per day (overnight at a special facility); and

3.       the CNG fuel cylinder(s) must be located in the trunk of the car.

4.

Design Procedure

1.       Determine the amount of natural gas required to make the delivery route for the selected automobile.

2.       Determine the compressed volume of this quantity of natural gas that will be the inner volume of the CNG tank.

3.       Select the inner and outer diameters of the tank based on the maximum stress formula. (See handout on Useful Relations)

4.       The length can then be determined to give the required volume.

You will be given three handouts—Background Information, Useful Relations, and Other Sources for Information—to aid you in completing this assignment.

5.

Deliverables

Each team must communicate its final design to the client in both written and oral form. Your written team report must contain the following from each team member: a scaled orthographic and isometric sketch of the CNG tank in the trunk.

Your written and oral presentations should also address the following questions.

      1.   What are the difficulties associated with this conversion?

2.   Are their any potential tax breaks for our investment?

3.   How much less carbon dioxide could you expect to produce in a year?

Lesson | Instruction to Students | Background Information | Useful Relations | Other Sources for Information