TERS : Thermal Energy Recovery System

[aussiegman]

Regarding recovery via exhaust turbines, how can the turbine only recover genuine waste energy ?
Essentially a turbocharger doesn't run on (genuine) waste energy, it runs by creating a back pressure (that it puts to very good use).
A turbine is a fluid-mechanical device driven by pressure difference (like a piston), not a magic device that turns heat as such into work/power
Additionally there's many ways in which the turbine can be deliberately fed either temporarily or not , and ultimarely it would come down to philosophical debate.
The practicalities of policing drive the rules (sooner or later)

Are you certain that is how a turbo charger works??
Are you sure it does not recover genuine waste energy in the form of heat from the exhaust??
Are you saying that there is no device that can turn heat (thermal energy) into kinetic energy (work) outside of magical devices??
Are you certain that a turbo is primarily or only driven by the "back pressure" or pressure difference it creates across the turbine??

If so would resolutely and absolutely disagree with these presumptions/assumptions and further submit that a turbocharger operates primarily on recovery of waste heat energy which is not a magical act but simple physics...

[netoperek]

I know it probably won't ever happen, but I for one would like to see some variation of Stirling engine as a TERS device Would look epic

[Cam]

Here's a link to a presentation with some nice info, graphs and stats from DEER in 2005. Tech has probably come a long way since then. Interesting to see they've been working on it for a while.

Edit: Their conclusion "Around 10% improvement in vehicle fuel economy through thermoelectric waste heat recovery in gasoline engine vehicles in the next few years is achievable."

http://www1.eere.energy.gov/vehiclesand ... _crane.pdf

[Tommy Cookers]

the above interesting paper reminds us that in F1 use an engine dumps as much energy in the form of heat in the exhaust flow as it delivers in the form of work from the crankshaft (in road use it dumps even more)

so a device that turns exhaust heat into work could double (or more than double) the efficiency of an engine !

the exhaust turbine and turbocharger seem very far from this ideal


the paper also reminds us that much of the economy benefit of the car diesel exists only in our skewed European perception
(also how much heat it dumps to coolant)

(relative to gasoline) diesel fuel is substantially denser (more energy per gallon) so mileage per gallon flatters the car diesel,
in crude oil consumption terms or (whole life) carbon terms the economy less impressive
(similarly bioethanol mpg is much worse than gasoline's, but we are being trained to ignore that disparity)

[Cam]

This TERS has got me mighty intrigued. I have further info to post, so more to come.

Here' a paper from the Department of Mechanical Engineering University of California in 2000: This work investigates a purely thermal control system for HCCI engines, where thermal energy from exhaust gas recirculation (EGR) and compression work in the supercharger are either recycled or rejected as needed.

Enjoy: https://e-reports-ext.llnl.gov/pdf/237490.pdf

Edit: added pic from paper for relevance.

[Cam]

Another one (presentation) from GM in 2005. Discussing TE from exhaust and radiators.

http://www1.eere.energy.gov/vehiclesand ... r_yang.pdf

[Cam]

Heat recovery overview via a TurboSteamer, presentation from BMW in 2009.

A 15% increase in engine performance could be demonstrated with a Dual-Loop-Rankine and 10% increase in engine performance could result from a Single-Loop-Rankine.

http://www1.eere.energy.gov/vehiclesand ... bieglo.pdf

[aussiegman]

I still think what will primarily be the result of the TERS is a turbo charger (which converts heat energy from the exhaust into kinetic energy of the turbine wheel and shaft) that includes an electrical CHRA that has both a generator mode to produce electricity to drive the KERS type electrical motor and a drive mode that provides for decreased spool time and transient response.

Other systems are either:

1: To cumbersome from a weight/packaging standpoint;
2: To fragile to remain usable during racing; and/or
3: Still in their infancy and not well enough understood to be made robust and weight effective is enough.

[pgfpro]

I still think what will primarily be the result of the TERS is a turbo charger (which converts heat energy from the exhaust into kinetic energy of the turbine wheel and shaft) that includes an electrical CHRA that has both a generator mode to produce electricity to drive the KERS type electrical motor and a drive mode that provides for decreased spool time and transient response.

Other systems are either:

1: To cumbersome from a weight/packaging standpoint;
2: To fragile to remain usable during racing; and/or
3: Still in their infancy and not well enough understood to be made robust and weight effective is enough.

I 100% agree!!!

I think the new F1 turbo/generator's are already being tested with great results. This technology was patent in 1999 US5906098. Its had a lot of time to be refined.
http://www.google.com/patents?id=7P4XAA ... &q&f=false

[netoperek]

how about putting Tesla turbine(s) on the exaust? It's light, quite efficient and... I would really like for some of Tesla's technology to have a recognition it deserves
It was problematic in Tesla's times, but today's technology should overcome weaknesses they had, especially on F1 level. What do You think?
Anyway, I really hope TERS will have some extraordinary or at least unexpected solutions to it. The way I see it, F1 should develop brand new technologies, not just expensively improving old ones. I know current rules system is efficiently slowing the race of ingenuity or inventivety, if You like, but wouldn't You like it if it was that way?

[Cam]

I still think what will primarily be the result of the TERS is a turbo charger (which converts heat energy from the exhaust into kinetic energy of the turbine wheel and shaft) that includes an electrical CHRA that has both a generator mode to produce electricity to drive the KERS type electrical motor and a drive mode that provides for decreased spool time and transient response.

Agreed 100%. While there seems to be several approaches, exhaust gases through a turbine seems the most practical.

Here's another paper that focusses on that subject. I have found another document by Volvo who are looking at the same thing as this.

RECOVERY OF EXHAUST GASES ENERGY BY MEANS OF TURBOCOMPOUND

The paper gives an analysis of solutions of turbocompound action: mechanical and electrical. Traces of power obtained by the turbine and power demand for driving the air compressor are also shown. A graphic presentation of power that maybe recovered from exhaust gases energy by application of these systems is also given.

The last part of the paper contains conclusions on turbocompound systems and their advantages.

Application of these systems permits:
Increase in attained power even by 10-11%,
The torque increase as well by about 11%,
Fuel consumption is reduced by 5-11%.

http://www.heat2power.net/competitors/t ... chmark.pdf

[Tommy Cookers]

..... this is all related to diesels ?
(with spark ign there is a tradeoff, induction boost vs piston expansion ratio)

the Caterpillar plot shows compounding alleviating a surplus exhaust energy problem caused by unregulated turbocharging ?

do the F1 'TERS' rules allow (as in the paper) seperate turbines for power recovery and for driving the compressor ?

the only design flexibility in the rules is high revs, low boost, high expansion ratio or the opposite
(surely high piston ER would win without the demand for electric power recovery aka TERS)

do the rules mandate a minimum EPRT capacity ? (related to the obscuring of KERS with TERS?)


for ordinary road (car) use engine downsizing via centrifugal supercharging (driven electrically or by electrically modulation of differential input gearbox) with EPRT seems technically plausible, and credible as TERS
(once you have all this electric system capacity there's a lot of options)

[Cam]

Yeah there's not much publicly available for modern petrol engines so I guess we have to see what the other industries are doing and try to see how they may work into a F1 car. Until they give us the blueprint I think we have to put these pieces together ourselves.

[aussiegman]

IIRC the TERS allow a single turbine so no separate systems.

This is one of the main reasons why I think that a single turbo charger with an electrical CHRA generator/motor unit will be the system that is most utilised.

It has significant advantages from a packaging (weight & size), power output, robustness and thermal energy recovery standpoint as well as being a very mature and well understood technology (so cost effective). The primary issue has previously been the thermal insulation of the CHRA electrical motor/generator, however I have seen a number of systems where this has been mostly overcome.

[Tommy Cookers]

Regarding recovery via exhaust turbines,

NOTE to self ......

R.K.Rajput in his ICE book says (p522) that a turbocharger 'extracts' up to one third (of the exhaust energy)
(and ... losses, related to 'back' pressure)

Wright 'Turbo-Compound' recovery adds 6% to power in cruise (my earlier post was wrong) and up to 18% to takeoff power
(the CR is standard at only 6.7 and blowdown starts with 200 psi in the cylinder, instantaneous pressure in the sonic exhaust flow to the turbine never exceeds 10 psi, 'back pressure' is small, and importantly becomes favourable late in blowdown)
the TC turbine conditions and use (designed for lowish altitudes and speeds) are similar to modern car turbos
(engines for higher altitudes and speeds recovered energy from exhaust optimised as a jet, hybrid systems were possible)

the above seem consistent with the (consensus?) view that a turbo SI engine can be about 35% efficient currently
(and does not suggest that a turbine can recover most of the exhaust energy, that would give 55-60% efficiency)