Thermal science research at GE

Todd Wetzel

imgI’m Todd Wetzel, manager of the Thermal Systems Lab at GE Global Research. My lab’s role is self-explanatory: develop advanced thermal technologies for the gamut of GE’s products.

Basically, every physical product that GE sells – jet engines, power plants, locomotives, medical equipment, electronic equipment, appliances, etc. – is limited in some way by temperature. Don’t believe me? Go ahead and try me: send me any example of a GE product, and I’ll tell you how it is limited by temperature.

But many GE products are obvious in their thermal limitations. The best examples are jet engines, and their gas turbines cousins in power plants. In both of these machines, thermodynamics dictates that engine efficiency improves substantially as the temperature of combustion is increased. In contemporary jet engines, combustion temperatures are so high that even exotic metals could never survive if left to their own. Therefore, all components in the ‘hot gas path’, or the region downstream of the combustor, utilize sophisticated cooling technologies to allow these parts to survive the harsh, high temperature combustion gases they touch. For decades, researchers at GE have developed increasingly sophisticated cooling technologies to allow jet engines to be safer, more reliable, and more fuel efficient. (See picture of the jet engine blade with this entry)

Another area of research for my group is electronics cooling. GE has so many products that are steeped in electronics – Healthcare, Sensors, Lighting, Security, Appliances, even Energy and Aviation. In all cases, we work to develop advanced cooling technologies that allow our products to have superior performance over our competitors. That advantage might mean higher heat fluxes, more processing power, lower temperature, longer life – whatever the product designers and ultimately our customers need. Power electronics devices need amazingly high heat fluxes. We realized several years ago that this necessitated the development of liquid microchannel heat sinks. Microchannels have been known for 20 years to be capable of providing exceptional cooling heat fluxes, but they have been challenging to implement due to manufacturing issues, clogging, pressure drop, etc. Over the last three years our researchers have developed a new and patent-pending implementation of microchannel heat sink, which we believe is among the best in the world in achievable heat flux. We were invited to write an article for Power Electronics Technology, and our article was featured on the cover of the magazine!

Got any questions about thermal sciences at GE? Feel free to submit a comment on my blog.

Comments

hey Todd! Great blog! What’s new in the world of heat recovery for internal combustion engines?

What techniques do you use to simulate flow and heat transfer? What role does turbulence play in your research?

Dear Todd, would you please pass this on to whoever at GE. And thank the boss for being so forward looking on global warming. May his tribe increase!

I have several ideas for “Imagination Breakthrough” inventions that I want to get out to you to develop at GE. I am in no position to make any of these happen as a designer in a non engineering field. However, being in the design field myself, I cannot stop possible solution type ideas from constantly bubbling to the surface on the area of most concern to me: global warming.

1. Add an automated Air Dry option to dishwashers: select Air Dry on the drying cycle, and dishwasher will open itself and slide out the 2 racks to airdry. We are at work or asleep when the dishwasher is going. We’re never around. This will make it happen every time. Save Co2.

2. Add windpower for hybrid cars. Put windturbine on roof, (lay it sideways)to recharge batteries when driving 55 mph: isn’t that like a 55 mile per hour wind for a turbine? Use it to recharge battery. Saves Gas: reduces Co2.

3. Add 2 Solar panels on top of that to add to wind tunnel effect and also makes it a Solar+Wind powered hybrid: the underneath Solar panel should slide down over the front when you are parked to cover from roof over front windshield down to bumper for extra Solar coverage, plus keeping car interior from getting too hot, so reducing air-conditioner use, also reducing Co2.

4. Design Solar Parking buildings available to electric car owners. Put intensive Solar on the roof. Use to recharge batteries of electric cars plugged in during the day whlie at work.(And GE should of course make the electric car we all want to plug in there. Only you have the busiess clout to overcome resistance by Detroit. They just don’t get it, never will. Please create electric car.)Both car and parking building reduce Co2.

5. Solar Clothes Dryer:

a. old-fashioned clothesline drying had the advantage of a great fresh sunshiny smell

versus

b. convenience is the advantage of the Clothes Dryer:

Convenience won: you just throw your clump of wet clothes in a box, flick a switch and its done. No one will go back to carting clumps of wet clothes outside to clip on a line, but if you combine the advantage of a. and b. I think they would.
I would.
So how about a box you throw the 10lb clump in, like now. But the box gets rolled outside. Think smaller supermarket cart: its all mesh to let the sunlight and fresh air in. It has wheels. Roll it outside in the sun.
Roll the cart to connect to a Solar Oven type box with a Solar powered 12 volt motor(or its some size like that now in my dryer) motor that makes the mesh box tumble around to dry the clothes in the Solar Oven, just like the motor does in current dryers. But there should be a way to let air(wind) in sideways as well.

The clumps of wet clothes should be separated like dishes are in a dishwasher. Maybe a sideways fanned out type of arrangement would work well. Underneath the motor is a Solar Oven type heat-concentrating reflecting heat upwards.

The combination of slight wind (created by the Solar motor tumbling the clothes, with air vents, and the solar oven underneath would provide the air and heat needed to dry the clothes.Reduces Co2.

6. Marketing idea for CFLs. Currently theres a lot of resistance because the package says if you buy this CFL you need to find a nuclear waste dump or something somewhere to dispose of the Mercury. This unneccessarily alarms people and they won’t buy CFLs. Instead setup CFL instore recycling like the Printer Cartridge industry did for Printer Cartridges. I don’t even know what bad stuff is in them, but its easy to recycle them, so I do it.

Look I know all this is beneath you dealing with such science as “simulate flow and heat transfer”, but I have no way to get this to who it should go to, to develop. And GE is at least adressing global warming in general.

So, sorry to bother you with all this. Now I can focus on my own work.

Totally agree

Rich,

We have a lot of different ways that we simulate flow and heat transfer in our labs. Many of our experiments are actually specialized wind tunnels, since we are often studying convective heat transfer. We will then often set up the heat transfer portion by using electrical heaters to provide a well-controlled heat flux on the surface we are studying.

Turbulence is a CRITICAL aspect of our research. Part of the expertise my team has is in knowing how to set up an experiment such that the turbulence and other flow quantities are appropriate simulations of the real life component.

Thanks for the questions!

-Todd

Do you use any software or computer code to numerically simulate the convection heat transfer? Or you just do experimental research? Thanks!

What is differeance between GE-90 and GE-115…..Is there any study material to know about the GE engines…..

I believe the steam-cooled 9H gas turbine (H-system)is a product of GE research. I am just wondering, is it possible to extend closed loop cooling technique to gas fuels? Instead of steam, gaseous fuel is used as a cooling medium circulated in the turbine blades This allows pre-heating of the fuel, improving combustion efficiency. This could also serve as an alternative to the air-cooled 3rd stage turbine blade of the 9H, reducing compressor bleed and improving output and efficiency.

Hi Todd,

I would appreciate it if you could respond to a quick question on retrofitting an inlet air cooling system to a CCGT power plant. How can an inlet air cooling (e.g., fogging and chiller) system recover lost capacity (MW) of a CCGT unit as well as gas consumption per unit of output (MHh) in a hot environment (e.g., ambient temperature > 15 C)? Thank you.

Dear Todd: Dec 18, 2008

Could I mail you a novel application of solar
thermal energy ? I would appreciate any comment.

Thanks Ralph

Thank you for posting about this, I would like to read more about this topic.

Greetings from Tim.

Where is the Black Swan?

Nice topic. I want to know more on this. Can I use this cooling system in my house? How about my electricity bill how much do I pay? Is it low or high? Because I’m using water cooled chillers and it’s very cheap when terms of my E bill. Thanks

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