Placeholder Image

字幕列表 影片播放

  • LONNIE JOHNSON: I'm going to talk about something that

  • has been touched on routinely throughout this conference--

  • the fact that we're in an unsustainable situation

  • with respect to energy.

  • We're hooked on dirty energy sources.

  • And we have inefficient means for converting those images

  • sources to work or power, even for refrigeration.

  • Imagine what would happen if we had a universal engine that's

  • more efficient than any engine that's been built before

  • and that would be versatile enough

  • that it could be used for large-scale power plants

  • for converting heat to useful power, but yet small enough

  • that you could actually use it convert body heat

  • to power to power personal electronics

  • or even harvesting energy from ambient environment using

  • the temperature variations in our environment

  • that we routinely take for granted.

  • Energy that could be used irreversibly for refrigeration

  • and air conditioning applications--

  • we could actually power and provide power and refrigeration

  • to remote, undeveloped areas of the world.

  • When you think about energy-- and the ideal sustainable

  • energy source is, of course, the sun-- there's

  • enough energy falling on a small area of desert, as shown here,

  • that could supply all of the needs of the world,

  • but yet we don't have the efficient conversion technology

  • and the cost effective technology that

  • would be able to do it.

  • So imagine if you could have an energy conversion system that

  • could convert this energy to useful power

  • at a cost that's competitive with coal,

  • natural gas, and fossil fuels.

  • I get very concerned when I hear people

  • talk about clean, natural gas, clean burning natural gas.

  • The fact is, natural gas is a hydrocarbon.

  • When you burn it, you get two reaction products.

  • The hydrogen reacts with oxygen to produce water, good.

  • The carbon reacts with oxygen to produce CO2, bad.

  • So you don't get around that.

  • So we really do need a sustainable energy source

  • that's really good for the environment.

  • Aside from having an effective, clean way

  • of supplying and sustainable way of supplying energy,

  • we also have an engine that could

  • allow us to use that energy more efficiently.

  • For example, buildings-- and it's

  • been talked about before here-- consume about 40%

  • of the energy that's produced in this country.

  • About 2/3 of that is used for heating, refrigeration,

  • air conditioning, those kind of things.

  • If we had an efficient technology,

  • we could actually cut that consumption in half.

  • That would be a profound effect.

  • I'm a proponent of electric transportation.

  • In fact, I'm developing battery technology

  • that could take that to another level.

  • But if we had to rely on fuels, if you

  • had a more efficient engine, what if we could cut

  • the amount of energy consumed for transportation in half,

  • almost 30% down to about 15%?

  • That would have profound implications for us.

  • When we think about engines, we generally

  • think about mechanical devices.

  • And the way they work is you compress

  • a working fluid at low temperature.

  • You heat it up and expand it at high temperature.

  • That hot temperature expansion gives you a lot more

  • work out than it takes to compress it at low temperature.

  • All engines work this way.

  • They generally do it by turbines, pistons, and things

  • like that.

  • Even refrigeration systems operate in reverse.

  • You compress the gas-- it actually

  • gets hotter when you compress it-- you

  • dump that heat off, bring it back

  • to your ambient temperature, then you expand it.

  • When you expand it from that ambient temperature,

  • it cools, and that's how you get to refrigeration effects.

  • So it's all about compressing and expanding working fluids.

  • We're taught in thermodynamics that the Carnot cycle

  • is the ideal cycle for converting heat to work.

  • It's represented by a rectangle and if temperature entered

  • the space, you'd have a high temperature expansion

  • and a low temperature compression.

  • This is an ideal curve for a Carnot cycle.

  • What's significant about it is that if you look at it,

  • internal combustion engines burn gas

  • at temperatures that are way off the scales

  • here, up around 2000 degrees centigrade and higher.

  • Yet the efficiency that you get here

  • from an internal combustion engine is only about 30%.

  • And you can get that with an ideal Carnot engine on a heat

  • source for about 200 degrees centigrade.

  • So it's a lot of energy loss, the engines that we presently

  • use are very inefficient.

  • So the JTECHH is basically an engine

  • that operates the same way.

  • We have a membrane electrode assembly stack,

  • not too different from what you would find in a fuel cell.

  • It's a proton-conducted membrane with a couple electrodes

  • on either side.

  • By applying power to this membrane,

  • you're able to drive hydrogen from low pressure

  • to high pressure.

  • That hydrogen goes through a heat exchanger

  • to the high temperature section of the engine, where

  • you have another stack that's at high temperature,

  • and you allow the hydrogen to expand

  • from high pressure, high temperature

  • to low pressure, high temperature.

  • Here is the high temperature expansion

  • where you get a lot more energy out,

  • and energy comes out directly as electricity.

  • You have enough that you can supply

  • some back to the low temperature stack and keep the compression

  • process going so you have a continuous supply

  • of high pressure hydrogen to the high temperature

  • section of the engine.

  • Not too different from what you'd

  • find in any conventional engine.

  • For example, I've got a jet engine here.

  • I've talked about internal combustion

  • using pistons for this process.

  • But here, you have a jet engine.

  • You're pulling air in at ambient temperature.

  • You have a turbine that's compressing it

  • to high pressure.

  • You supply the fuel, you burn the fuel, you heat the gas up.

  • Now it's expanding at high temperature from high pressure

  • to low pressure.

  • As it expands across the exit turbine here,

  • some of that work energy is extracted,

  • and it's coupled back to the front of the jet engine

  • to keep the supply of compressed air coming in.

  • So it's a self-sustaining process.

  • So you can see the similarities between the two engines.

  • The significant difference, though,

  • is that this engine operates on what's

  • called a breaking thermodynamic cycle, which

  • is less efficient than Carnot.

  • The JTECHH operates on the Ericsson thermodynamic cycle,

  • which is equivalent to Carnot.

  • So we have the potential for really achieving

  • a very high efficiency.

  • Here's an example.

  • The sun, as I referred to earlier,

  • is the single source that will be

  • able to meet the terawatt levels of power that

  • are going to be needed by the world in the future.

  • Here is shown the high temperature stack as I just

  • described it, and the low temperature stack here,

  • where we're cooling it using ambient air.

  • Here your stacks focus solely energy

  • onto the high temperature stack.

  • Here's a practical implementation of the engine.

  • Interesting thing about this.

  • Solo sales were attractive, competitive,

  • even though their efficiency is low.

  • But they're attractive because they are solid state.

  • They're very reliable.

  • There's nothing really there to fail mechanically.

  • You don't have an ongoing maintenance problem

  • rather than cleaning them.

  • On the other hand, the sterling engine is a mechanical device.

  • It operates on the thermodynamic cycle.

  • It's a lot more efficient than solar sales.

  • But the problem with it is that it's mechanical.

  • It requires maintenance.

  • Things are going to break.

  • And so the maintenance cycle for that system

  • makes it less than ideal.

  • The JTECH, of course, offers the best of both worlds,

  • because it's all solid state so you have a higher reliability.

  • It operates on the thermodynamic cycle

  • so you have the high efficiency.

  • Here's a chart here showing some examples.

  • I've got an internal combustion engine here, a car engine.

  • You can see the efficiency, around 30%.

  • This is a state-of-the-art power plant, about 40%.

  • JTECH operating on heat, coming in at about 1,000 degrees

  • as the solar powered JTECH is the example here.

  • Our model suggested we can achieve about 85% of Carnot,

  • in terms of our conversion efficiency,

  • because in the real world, you will have lost this.

  • If I were to take the internal combustion engine

  • and add a JTECH on top operating on waste heat

  • from the internal combustion engine,

  • you can get some pretty impressive efficiencies here.

  • When I do this chart, sometimes people say well,

  • how do you exceed Carnot efficiency?

  • That's really can't be.

  • But remember, the internal combustion engine

  • is actually burning fuel up here at about 2000 degrees.

  • So your Carnot potential is a lot higher.

  • You get high quality waste heat from it, and use that to power

  • the JTECH.

  • Any refrigeration applications?

  • The US, back in 2006, the government

  • increased the seasonal energy efficiency rating

  • for air conditioning systems from 10 to 13,

  • and they projected that that would avoid the need

  • to construct 39 400-megawatt power plants,

  • and that we would reduce the CO2 emissions

  • by 33 million metric tons.

  • The JTECH could increase that CO2 to about 26,

  • which would avoid 130 400-megawatt power

  • plants, and 110 million metric tons of pollution

  • to the environment.

  • Aside from the fundamental advantages and benefits

  • from the JTECH itself, being able to do the research, just

  • conducting and developing the technology,

  • will have a number of spin offs, not only

  • for pumping hydrogen, but actually-- hydrogen production,

  • electrolysis, compressing hydrogen, storing it,

  • supplying it.

  • So if we do go to a hydrogen economy,

  • this technology would benefit that.

  • But cryogenic cooling, refrigeration,

  • a wide range of applications that

  • would come as a result of that.

  • So to sum up, the JTECH is a universal engine

  • that has benefits across the board just about anywhere

  • you would have an engine application.

  • The really neat thing about it is not only does it

  • allow us to get green, environmentally sustainable

  • energy sources, but it also improves the efficiency

  • by which we will be able to use that energy.

  • Thank you.

LONNIE JOHNSON: I'm going to talk about something that

字幕與單字

單字即點即查 點擊單字可以查詢單字解釋

B1 中級

X的解法 - Lonnie Johnson--熱能直接轉化為電能 (Solve for X - Lonnie Johnson - Heat Direct to Electric Energy)

  • 36 3
    richardwang 發佈於 2021 年 01 月 14 日
影片單字