710 exhaust manifold insulation

[RickRackstop]

In virtually every marine application and some emergency generator sets the owners have installed aftermarket insulation blankets, mostly to reduce engine room temperature but with the added benefit of increasing the turbine inlet temperature and airbox pressure. For some reason 12-645E5's are mostly benefited with the turb spooling up much faster.
On a nuclear unit they recorded a reduction of 11% on the fuel rack for the same output on the watt meter. Of course the first reading was with the heat shields in the dumpster and a bare manifold so the shields might be worth 5%. Someone at research center in Texas thought that the newest engines from EMD mite now have them as standard equipment.

[GOLDEN-ARM]

Welcome to the RR.Net Forums!!!
Was this a question, a statement, or just a musing? As a railroad forum, I don't see the tie in, for the marine section and the nuclear section.I see the topic is about 710's, but you speak about 645's, then go on to guess about percentages due to the manifold shields. No mention of what that percentage means though, and finally some guy in Texas thinks "they" might be standard equipment? What are "they", the blankets, or the shields? We don't run on rumors or inuendos here.

[RickRackstop]

Yes I wasn't clear I wanted to verify that all production engines at this time have factory applied insulation as the benefits have been known to everybody it seems except the factory. The picture on the side of the GP22 seems to indicate that it is.

[QuietGuy]

The exhaust tube from the cylinder goes right through the water manifold on the top of the engine, so a great deal of heat is lost right there in the manifold. Some experiments were done with insulation INSIDE the exhaust tube, to reduce the amount of heat lost to the water manifold. It was a fine line between squeezing the size of the manifold with insulation, thereby reducing the area and reducing the amount of exhaust that could be releived from the cylinder after combustion and having enough insulation to increase available heat for use in the turbocharger. There was a strong case for insulation to be installed, especially with the amount of power lost to meet Tier 3 emission standards. Unfortunately I left the company before any meaningful work was done on this concept. This is a simplified statement of the problems involved - there are fabrication issues too complex to discuss here, so don't try to overthink this unless you are a real expert in welding, thermal expansion & stresses, forging manufacturing, precision machining of large, heavy steel parts, turbocharger performance, computer modeling of these systems using FEA & CFD, etc. I am not the expert, but I was there and did a small part to look at these items.

[RickRackstop]

This all started because I noticed that all of Southwest Research's engines had an insulating blanket on it and if anybody would know about collecting data on this subject it would be them. They didn't know but assumed that EMD was putting insulation on exhaust manifolds but I would have to contact EMD. I did and have still have not received a reply.

I could go on and on about this subject but it will get too boring. If one of you railroad engineers get a chance to get on a new locomotive you take your flashlight open the door and take a peek then report back.

[Super Seis]

Nothing new here...basic thermodynamics of IC engines are at play.
Alco applied insulation to the exhaust manifold and turbo on the early 244's...those equipped with the GE turbo.
DLW has been doing this on their recent Alco 251-equipped loco production.

Of course, the challenge in railroad service is ensuring that the mechanics replace the stuff after performing top deck maintenance.

SS

[MEC407]

Rick,

Check out this photo of a relatively new 710 with the hood removed:

http://www.railpictures.net/viewphoto.php?id=262211

Is that the insulation you were talking about? The silver wrap around the exhaust manifold?

[RickRackstop]

Rick,

Check out this photo of a relatively new 710 with the hood removed:

http://www.railpictures.net/viewphoto.php?id=262211

Is that the insulation you were talking about? The silver wrap around the exhaust manifold?

This is a very interesting photo. At first I thought it was a 645 with add ons, but after looking at the aftercooler detail I see that this is the latest tier 2 setup. Then I read the photo data so I guess we can conclude that this is the factory insulation replacement for the heat shields. What sets me off is that the aftercooler has fresh paint on it and the piping is not painted at all. It is possible to add all this stuff to older engines including 645's to improve thermal efficiency as well as reduce pollutants. There is a Firwin company on the internet that specializes in insulation of this type and have there's is a picture of an blower engine (E6) as well custom insulation up the exhaust pipe to the muffler to the stack.