×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Heat Exchanger Testing System

Heat Exchanger Testing System

Heat Exchanger Testing System

(OP)
Hello All,
I’m beginning to add new components to our testing system that has been through several upgrades already. This system is designed to test heat exchanger and oil thermostat performance. For the scope of this post, I will be concerned with only the heat exchanger. We use an electric gear pump to move engine oil through SAE -10 ID hoses and fittings. The oil is drawn from a heated reservoir (a cheap food fryer at the moment). The heat exchanger sits within our homemade wind tunnel. A 3-speed radial blower is what moves air through the tunnel.

Once the engine oil is at the temperature that API/SAE uses to rate their viscosities, we set the flow rate with a manual valve (A) and analog flow meter (B). We also set line back-pressure using a manual valve (C) and analog pressure gauge (D). The oil is still being heated by the fryer. It was short-sight how this adjustment would prove to be erroneous which is why we have the oval gear flow meter now. The oil changes viscosity as it gets heated and diffuses heat, and thus changes flow rate(s). The oval gear meter will now accurately record the oil flow rate so that the heat equations and their values don’t become erroneous. Being that the ambient air’s thermophysical properties don’t necessitate precise flow metering, I’m using a bulk average flow rate calculated from another round of testing.

Here’s some more background regarding the evolution of our test system; I’ll make this short. I was part-time here at the company until winter of 2015. We still had this garage way of testing things that I was used to operating as a part-time employee. As a full-time employee, I knew that overalling the testing system was on the docket. Opportunistically for us, my boss’ cousin was laid-off from Cummins so he helped my boss with the project. I provided a lot of literature for wind tunnel design, but had very minimal input on the overall design and component selection/integration. My boss had an idea of what he wanted it to do and they sort of worked on it from there.

Unfortunately, there have been several later upgrades due to the fact that due diligence was not carried out in designing the original system, and/or lack of knowledge regarding testing systems. It’s now up to me (and the financial support of the company) to get this system where it needs to be.

I got down-and-dirty in my roommate’s graduate heat transfer book to refresh my brain from a far more thorough source of information than my undergrad book. I also picked up Compact Heat Exchangers by Kays and London since I needed access to some discrete heat exchanger details.

I had to sell the sh#t out of my intended upgrades to get a few of them approved. I have some of these parts on order or in my possession now: proper line and tank insulation, an oval gear flow meter, as mentioned before, and some extra thermocouples.

I’ve ordered some Armacell pipe and component foam that I will be using to insulate the lines and tank to minimize energy lost to the surroundings.

The other upgrade I got approved were two more thermocouples. I really wanted about nine fore and maybe 20 aft, but that wasn’t in the budget to get a new DAQ for those. Instead I’ll be doing point traversing. The textbook says that they did 9 point traverses fore and 27 point traverses aft of the exchanger. I’m going to try and set it up as 10 and 20 so that it works out better when timing the point traversing in 30 second or 1-minute intervals.

I also wanted to install an electric motor controller for the oil pump and radial fan that’s related to the thermal load of the system and windspeed, along with a truly-capable oil heater. Ideally, I want a fully automatic, non-human input testing system, but those are always pricey.

After designing the point traversing apparatuses for the fore and aft positions, I’m wondering how to best carry out the actual traversing. I’m thinking it’s going to be best to start the measurements at the inlet (hot) port. Then at some time interval I will begin moving the thermocouple down the core, as shown. Once I’ve completed all the Y values for that X-point, I’ll move to the next X-point and repeat until the whole heat exchanger has been done, fore and aft.

Does this seem scientific and practical enough to get the best bulk average temperatures for the heat exchanger core? Some of the heat exchangers tested are going to be dual-pass cores; I am wondering if those will need to be treated differently?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close