Communication File

Communication File

4/23/2012

I was just reading that FEMA manual again to find some information for the report, and I saw something we haven't tried. It says that for diesel engines running on syngas, people used to start the engine with diesel fuel, then switch to syngas, which would then keep the engine running. I wonder if our engine might have been behaving the same way, trouble starting, but not as much trouble continuing to run once it's started.

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-Jaime Conley

4/22/2012

Team,

The videos are posted on youtube. go and type in odu pegasus and they should come up. just a note, video part 5 had some elapsed time after part 4 since i had to spend a few minutes adjusting the mower in between. these videos are at least the correct orientation and will work better for presentation purposes.

-Jonathan

Hey Guys,

I re-wrote 2 pages on the hardware updates since the midterm for the final report, I left some space at the end if someone wants to finish it or make adjustments that's fine.

Thanks,

Ben

Can patrick or jaime upload a test powerpoint (.ppt) on the website so that we can see if it works tomorrow morning on ODU's internet? I dont know if it would also be a good idea or not to update the other powerpoints on the website so they all work (for grading purposes). the gantt chart should also be closed out and updated.

-Jonathan

If nobody else has reserved a room in the library for tomorrow, i reserved room 4 (1405) from 9-11

-Jonathan

I decided to go out this morning and try one last time to get the thing going,especially since we have run the engine before using just charcoal and air. I got the engine running again!! Not for too long at times, but the videos are better than before. I will give you guys the youtube links once they're uploaded.

-Jonathan

4/19/2012

Team,

Dont be freaked out if you see the gasifier sometime today. i went there last night and was taking everything apart trying to get to the top of the engine and open up the fuel intake. the carburetor is most likely completely blocked so gasoline cant even get into it. the problem with it running on wood-gas might just be a moisture issue. i am going to switch out the carburetor with the extra one and try to burn the engine out with gas. and then put everything back together. Also im going out there after mechanisms today (4:15) I need to replace the pull cord (on its last leg). I think i have an extra one at my house ill check. So nobody try to pull it today

-Jonathan

4/13/2012

Jaime, I typed this up real quick. I haven't looked the locations yet for alarms and extinguishers. I can put those in later

--

Jonathan Mills

Old Dominion University

Undergraduate ME Major- Senior

Jonathan,

This is excellent.

Team,

Please see the attached fire safety protocol. Before the next trial run (today, I think), please read and follow this protocol, and also please check for the closest fire extinguishers and fire alarms.

Could the first person on-site today please also update the document to include those locations with respect to the current gasifier storage and working area and forward to everyone? There is a copy in our shared Google docs folder. Could you also please print a copy of this completed document and bring to the site? We can store it near our working materials and tools. Everyone needs to know where it is, and it needs to stay in that location.

I have another fire extinguisher at home if there is not one close to the site. I can bring that if I need to. Please let me know. There is also a water hose on site, and I can bring another if we need it.

Thank you, everyone. I'll send another e-mail shortly with some info about today's test.

Jaime

4/10/2012

PEGASUS team members,

The prototype was found producing smoke today with nobody around. I extinguished it with water. The team must have a fire safety protocol established prior to the next trial burn.

Thank you.

SK

Please write a safety protocol

Stephen B Knisley, PhD

Professor of Mechanical and Aerospace Engineering

Batten Endowed Chair in Biomedical Engineering

Old Dominion University

238 Kaufman Hall

Norfolk, VA 23529

Jonathan & Patrick,

Could you two please put together a fire safety protocol and send to me?

Thank you,

Jaime

3/16/2012

Pegasus team,

Emmylou will do the research I mentioned in my earlier e-mail about gasifiers' use on various scales and if they are or are not used much on smaller scales, and why (pros & cons).

Thank you, EmmyLou. I ran across a paper yesterday that might be helpful. See attached. The paper is about biomass ash byproduct from gasifiers, but there is some discussion in there about the various scales at which gasification is used, how much at each scale, and some ideas as to why. You might just try some text searches in Acrobat to find the topics. I didn't read the whole paper. I was looking for information on phase changes of biomass, and this one popped up on my Google search. Looks like a British company, so their focus may be more on Europe than on North America.

Team,

Jim & I met today on software modelling. Patrick didn't make it. I know I have sent a lot of e-mails lately, and I think my invite may have gotten buried in there. We found the owner's manual for the mower (see attached) on the Briggs & Stratton site, which gave us a lot to work with. See below.

So far, Jonathan said he will get the couplings for the piping. I think this is the most important item we have to complete right now, because our success depends on a sealed system.

EmmyLou said she will coordinate with John to get the temperature gauge and take the readings next time it's run. She will also do research mentioned above (and below) for part of the final report.

Ben is working on the leaks, especially in the filter.

John did the last hardware minutes.

John,

Could you take a look at the mower throttle and carburetor to see if the throttle can be adjusted, and if there is a valve on the carburetor to adjust air intake? The owner's manual might help with this. I tried to find a repair manual that would have better drawings, but the B & S site wanted to charge $22 for that. Maybe we could order that if we think it's important enough and if there's enough $ in the budget.

Patrick,

Let's talk about modelling or about your helping out the hardware team for a while. There is a lot of hardware work to be done. I know you have done a lot of research on the software side as well. It would be huge if you could help Ben & Jonathan seal these leaks.

Jim,

Thank you for your help today. I know you've been working on the mower combustion model. Keep it up.

Once the piping is all sealed, I think there are a lot of tests and other things we can do that will help us move this puppy closer to the finish line.

Software team update:

The B & S manual gave us

*the cylinder displacement (fuel & air = 11.57 cu. in inches, once every other revolution),

*cylinder bore (diameter = 2.687 in),

*cylinder/piston stroke (cyl length minus a tiny part for combustion to occur and to prevent the piston from slamming into the cylinder: 2.047 in.).

* the RPM's for which B & S calculate their Torque (3060 RPM) and horespower (3600 RPM) ratings

We came up with (11.57 cu in) * ((3060 RPM) / 2) * (1 min / 60 sec) = 295.035 cu. in. / s. That should help us sync up with what's coming from the gasifier.

(Note: based on the displacement, we figured out that the cylinder is 0.006634 inches longer than the piston stroke, which makes sense.)

We also worked on trying to figure out the fuel to air ratio of the CO and air coming from the gasifier, but I realized after looking at it at home that the equation I used was wrong. However, I think we're close to calculating that. This should help us determine whether the fuel & air density coming into the lawn mower is low enough and whether more heat transfer is needed. It should also help determine the carburetor air intake level. If we need more cooling, Jim had the idea of using an ice pack on the heat exchanger. <grin> We would just have to factor in how much cost and energy went into getting the ice pack frozen (and re-frozen) before we make any energy efficiency claims.

Then we took a swing at calculating the mass flow rate into the mower based on the 295 cu. in. / s (4.834E-3 cu meters / s) volumetric flow rate, using the ideal gas equation with 101.3 kPa, R = 8.3145 kJ/kmol*K, 298.16 K. I have m_dot as 1.975 E-4 kmol / s. To go from kmols to kg or lb, we need to figure out the ratio of CO to other products coming from the gasifier. My program has that for various temperatures, but I've been working with Dr. Taylor on that model, and it's looking like the model will change.

Dr. Taylor contacted me again (not sure if I've copied everyone on the e-mail yet or not), and I talked with him today. He worked over his notes and combustion model again and advised of some errors he had made in how he labeled the Hrp term for CO2, CO, and O2. These made it somewhat confusing to understand what was happening in combustion with this term, but now it makes more sense. He's going to fix his notes for future classes (I guess he gets to tell stories about me next semester, which is awesome. <grin>) I'm satisfied that the effect these components have in low oxygen conditions in the gasifier helps bring the temperature down below that of stoichiometric air and that my model scales their effects properly.

He also repeated his suggestion that I try using distinct temperature variables for the air and fuel in the model and to research how to model our solid fuel as a gas or how to account for the enthalpy change / departure from the solid wood to a gas in an adiabatic combustion model. He gave some good suggestions that I will follow, but that will take some time. We talked about how enthalpy departures can get very complicated, especially since they are generally for pure substances, not for mixtures like we have here. He recommended trying to keep only 5 products and not to get into trying to model dissociation reactions that could increase the number of products by a huge number.

I'm going to keep working on this and hopefully give you a better update Monday.

Thanks,

Jaime

I wouldn't mind doing the research for this. I'll start the research this weekend and bring it with me to the team meeting on Monday.

-Emmylou Dullas

3/6/2012

Larry,

I have an engineering senior design project going on that is rather remotely related: a non-fossil fuel gasifier to power an internal combustion engine, called the "PEGASUS" project. I guess the relationship is via; reduce fossil fuel combustion, reduce atmospheric CO2, reduce warming??, reduce sea level rise..

Do you want slides on that?

Stever

Stephen B Knisley, PhD

Professor of Mechanical and Aerospace Engineering

Batten Endowed Chair in Biomedical Engineering

Old Dominion University

238 Kaufman Hall

Norfolk, VA 23529

Please send me slides I can use to highlight CCSLRI research (or anything remotely related) at ODU.

At least two times a month I give a talk about the CCSLRI and related research at ODU.

If you can provide me with a few slides (ppt preferred) I can broaden the presentation and make it more representative of what is really going on here.

Thanks,

Larry

Larry Atkinson

Slover Professor of Oceanography

Old Dominion University

Norfolk VA 23529

2/28/2012

Jim & Jonathan,

Patrick and I have not been able to find the version of the powerpoint that we were working on in our meeting yesterday. We made changes to it at that time that we CANNOT now see in the version on Google docs. Patrick uploaded the version that is available now to Bawab's server, but it is not a finished product.

Can you guys login to whichever login you were in yesterday when we were working on this, find the correct version of the powerpoint presentation and make sure to SHARE it with everyone, so we can continue editing it and upload it to the website and our webpage?

Everyone,

I will contact Bawab and Haroon to advise we are still working on everything and that if they are looking for our report and powerpoint this am that we haven't finished. If it hurts our grade not having it done this morning, so be it, but I would rather turn in a more finished product than what we have now.

I'll let you know what they say, if anything.

Please feel free to edit the report and the powerpoint, once it's shared with everyone. We definitely need all hands on deck at this point. Just add whatever you think is important, to the report particularly, and anyone who is available in a few hours can get together with Patrick and myself by phone or voice chat to discuss editing.

Thanks,

Jaime

2/25/2012

Dr. Taylor,

I hope you're okay. Some my peers from Environmental Control and Gas Dynamics and I have been worried about you since you were sick last week.

Well, I'll get to the point. And I would completely understand if you don't have time to look at this and if would rather I ask you after class sometime. I would greatly appreciate your feedback.

I'm leading my senior design project in ME 435 (2nd sem), and we're working on our PEGASUS gasifier, trying to model it in Matlab to optimize syngas fuel production. I modified some of the programs I wrote in your Power Systems Design & Theory course last semester to try to model gasifier fuel production.

Basically, I'm running the C/H/O combustion program you outlined in that course based on the First Law, as a steady-state, single inflow, single outflow, no work i/o, no changes in PE or KE, using the enthalpies of the reaction of the fuel and for

CO + (1/2)O2 <=> CO2 dissociation, using the tables you gave us from A. Campbell to allow us to iterate for adiabatic flame temperature with enthalpy equations using approximations of the variable specific heats of the products of combustion as ideal gases.

I have been encouraged that we might be able to run the gasifier in excess fuel conditions by limiting the air intake, and successfully produce CO at temperatures below that we would expect for chemically correct air. If that's true, then I think we could get up to 60% syngas (neglecting water vapor), because the products would have so much less nitrogen and oxygen, and we could benefit from not having to get the flame temperature high enough to actually dissociate CO2.

That last part is where my questions get greater and greater in number.

I realize that the ideal gas specific heat approximation I'm using for the Hrp(Tr) of the CO2 dissociation reaction only works up to 900K, but I calculated some values for that equation using Table A.9 in the Borgnakke Thermo textbook, and the values I calculated are lower, but on the same order of magnitude and similar up to at least 2600K.

Here are some of the things I'm having a hard time getting my head around. In an excess fuel condition, let's say at Ymin, from what we learned from you, I am expecting that CO, with a lower enthalpy of formation than CO2, should be produced by the partial combustion process, instead of CO2, because there is not enough oxygen to react all the way to CO2. Now, given that, with the model you outlined for us, I'm using Hrp(Tr) for that reaction with a positive value, (as endothermic). However, from my reading I understand that the reaction isn't actually supposed to move significantly toward CO until the temperature of the reaction gets up above 800C (1073K) to 1000C (1273K).

So I'm wondering

(1) what to do with that Hrp value, wondering in what temperature ranges in an excess fuel environment it's accurate,

(2) wondering if it should actually be a negative value, since it seems that as CO, the reaction might be exothermic when operating in reverse, towards CO, away from CO2, or

(3) if in fact I should drop the term entirely in extreme excess fuel conditions, since at Ymin there theoretically isn't enough O2 available for the reaction to start.

I have experimented with dropping the Hrp value completely for this reaction in excess fuel conditions, and the flame temperature in my model shoots way up above the temperature at 100% theoretical air, ruining my hopes. <grin>

Also, the way we modeled it in the Power Systems course for excess fuel conditions was to multiply the Hrp(Tr) value for this reaction by the number of kmols of carbon monoxide in the products, without concern for the equilibrium constant of the reaction, which I understand, since we were mainly focused on excess air conditions at the time, for which the Hrp(Tr) value drops out of the equation, since there is no CO in the combustion products. Maybe that answers my question in a way. We were concerned about this term only when there was CO in the products of the combustion reaction. So, accordingly, my educated guess so far has been that the Hrp(Tr) value for the reaction is important, because even though the reaction cannot proceed without enough oxygen, energy is lost to the incomplete reaction (but how much?), dropping the flame temperature, proportionally to how much CO there is and perhaps inversely to how much O2 is available to it. As we move from Ymin to 100% theoretical air, the Hrp(Tr) value should have less and less significance, as there is less and less uncombusted CO.