I am not sure if it has been used before but we have discussed this before on CR4.

We came to the conclusion that there is never a free lunch so to speak as you would still need input from the engine to pump various substances around.

Have a look in the archives, I am sure you can find info on this.

Hello tcchandran

Great thinking!

The IC engine system, which has become prevalent as the most predominant mode of power source for the automobile has never been able to achieve more than 29 to 30% "heat conversion" efficiency; and all of today's automobiles waste a total of not less than 80% of the available energy - thereby reducing the ultimate efficiency to as low as 15% or lesser!

It is possible for us to utilize at least an additional 40% to 50% of the total heat energy, for which we need to devise and design mechanisms. One method is to convert the heat directly into electricity. Other electro-thermal and thermo-chemical methods may also be attempted.

This writer has been hoping to get answers for this, for some time now, and all of CR4 has only responded with the usual "hybridization" mumbo-jumbo. Please see the Discussion thread:

http://cr4.globalspec.com/thread/14678#newcomments

So far no REAL attempts to utilize the exhaust heat (and also the cooling system heat) have been made. In fact, this would be the real revolution of the future IC engine for the automobile - not the presently hyped "hybridization" mumbo-jumbo

Best wishes

pvhramani

Exhaust heat, or water heat from the radiator?

Yes, it is possible, on a property I go to that has no power (apart from plugging in the car) we have 2 refrigerators, they have a Kero (lately converted to LPG) flames under a tower tube, this is then heats some liquid in the back, and I'm not sure of the internals, but it does make ice inside, and keeps the food cold, have to keep it loaded as the internals can freeze everything ;o)

I understand that the air conditioning for a car requires several horsepower to run a compressor big enough for the job. The car is not insulated like a fridge, and there is a constant leakage of energy into the air conditioned air from the out side, either by air interchange or absorption of heat through the windows and the car body.

On the other hand a refrigerator is well insulated, and runs on a fraction of a kWatt to one or 2 kWatts and pumps 2 to 3 times this rate of heat. The fridge accumulates it "coolth" by slowly (relative to the constant cooling effect required of an air conditioner) pumping heat to the outside of the insulated cabinet.

The Electrolux style gas, kero, electric heat cycle fridge pumps heat at quite a small rate in comparison to the air conditioning requirements of a car. A refrigeration unit unit substantially larger than a gas/kero/fridge would be needed to air condition a car.

Perhaps the heat from a car could run a Stirling Engine, which in turn runs the compressor for an air conditioner. The hot side of the Striling engine is fed with the exhaust heat or radiator water, the cool side by the air from the car's movement through fins of a heat sink.

But it is still possible.

Better insulation of the car, windows and the like.

There was no stipulation as to how cold it was required to get, or the time to get to the cooler temperature.

cooling using the heat of exhaust/coolant is possible, but, problems come in when the limits get tightened.

a car is not insulated like a fridge, yes this is true, but on the other hand, how often does a fridge have to cool something that has been sitting in the sun for hours and is well over 70 degrees (it has been found that some car components inside the passenger compartment rise well over 120C) it takes a car air-con a long time to cool those parts pumping full.

Anything is possible, but not necessarily practical.

There was no stipulation on how cool the system gets, nor how quickly it cools things. Using common English meanins, a fridge and a car airconditioner have differing properties, requirements and are designed with those things in mind

A fridge is affective as a fridge even though it is only powered by a fraction to one or 2 KW because is is insulated and its main requirement is to cool and keep cool items over a long period.

A car air conditioner is effective as an air conditioner despite the fact that it is not well insulated because it is fed with several horsepower to deliver the main requirement, namely to make the occupants of a car comfortable whilst they are journeying.

As has been also said by others, the absorption refrigerator unit capable of air conditioning a car would be impractically large.

This one is powered by waste heat from an electric motor and solar collector:

https://www.freepatentsonline.com/4307575.html

It is interesting that the patent was issued in 1981, and in it they describe the subcompact electric and hybrid vehicles being developed. 27 years later, hybrids are just getting a foothold.

This one uses a desiccant, which is described as being rejuvenated electrically, but it would seem that exhaust heat would work:

https://www.freepatentsonline.com/5327739.html

Propane refrigerators are common in boats and recreational vehicles (motor homes) so the concept could be applied to vehicles as well, although such refrigerators are usually only run on propane when stationary.

But in any case, the idea makes sense as one means to make use of waste heat. I am not aware of an absorption system having been used in a car or truck -- although it seems that the very first air conditioners for cars might have been of this type.

You could, but don't. It would require a trailer or an extra large trunk to carry the equipment. These little gas refrigerators represent fractional horspower, whereas an auto requires multiple horsepower---maybe 5 HP or so.............................

Is it possible to use the heat of exhaust of an automobile to air condition the car with an absorption cycle?

It would not be practical as absorption freezers like to run in a level position they loose a lot of efficiency when they are being rocked around and would not produce enough cooling for air conditioning.

Though the waste exhaust heat could possibly be used with thermocouples to produce electricity to help reduce generator load.

I've had a couple of travel trailers with the gas refrigerators, and we didn't have any problem with malfunction. Look at the size of a 5 ton gas refrigerant unit, it won't fit in the trunk of a car...........The thermocouple idea could very well work, although not efficient. Gas floor furnaces are fitted with a "self-generating" electrical control system. A group of thermocouples surrond the pilot flame producing a small electrical current which energizes the main gas valve through a room thermostat. Since the floor furnace is a gravity heater, heat is available even in power outages.

have any of those who pretend that air conditioning systems relying upon wasted energy of exhaust and cooling systems of ic engines would be too voluminous, when considering the actual size of air conditioning systems in rv or gas powered freezers, ever thought that a car engine as an average wastes 75 to 80% of the heat produced by the fuel it consumes through its exhaust and cooling systems and that the energy contained in that wasted heat is so many times more than the 5 or 6hp they are talking about? i think that this should be a highly feasible idea.

I think what tcchandran is referring to is not an absorption refrigerator but a way of improving the efficiency of a conventional refrigeration system that uses ammonia as the refrigerant. This idea has been used in industrial applications for decades.

Long story short the ammonia is allowed to combine with water and the mixture pumped to high pressure. The ammonia is then driven out of the mix with the addition of heat. This technique allows the replacement of the compressor with a more efficient fluid pump. needless to say the efficiency gains are offset by the heat requirements, unless the heat is free.

The biggest problem with using ammonia in an automotive application is the accidental breach of the system. At best it would be like having a tear gas grenade go off in the cabin with you.

Instead of using ammonia in the system, a safer , less toxic system may be Lithium Bromide and water.This may not be as efficient as a hydrogen ammonia system but good enough for cooling purproses.

If you use lithium - bromide I would think you would have the problem of system freeze-up in Winter.

It is true that there may be a problem of freezup in winter, but I was referring this particular application to tropical climates where there is no winter and air conditioning is used to cool the air in summer and the coolest ambient tempearture is far above the freezing point.

I have done the design of an automobile air conditioner using Li Br using the exhaust gas as an undergraduate project during the year 1982 in Madras University. I do not have th project report copy with me now . I did it for Ambassador car.

Now I am in Gulf . I am seriously planning to design and fabricate a Li Br V.A cycle for one of the leading brands in gulf countries.

Suggestions are welcome.

Regards,

Dr. M. Ramaswamy

Dear Dr.Ramaswamy,

It is great to note that you are planning to design an automobile air cond. system using heat from exhaust gas.

I can work with you together on this because it has always been my dream to get something like this going.

Please contact me in the following address if you have no objection of my collaborating with you.

I have a few more ideas to utilise the exhaust heat like designing a stirling engine with a high torque and hooking it up with an air cond. system etc. More when we meet.

Dr.T.C.Chandran

Tel: 607 3884202

Fax: 607 3884203

Email:tcchandran@gmail.com

Appreciate your reply.

Thank you

Dr.T.C.Chandran

Dear Dr. Chandran,

Nice to recive your mail. I have recently submitted an abstract for a confernce to be held in Oman during Oct 2008. Abstract is given below . I request you to join with us in this work. Can u please inform me which country you are working now. From the phone no I am not able to guess. If it is in Indai I have to use the code 0091!!!.

With Kind Regards,

Dr. M. Ramaswamy

A feasibility Study to design an Automobile Air-Conditioner using Lithium Bromide –Water Absorption Cycle.

Ali Al Alawi, M. Ramaswamy*, Khalifa Saif Sultan Al Jabri**, Holger Gutgesell***

PDO, Oman

*Hospital Engineer (SBR), Rustaq Hospital, Rustaq; Sultanate of Oman

**Associate Dean, Sultan Qaboos University, Oman

***Gutgesell Renewable Energy Projects, Germany

Abstract:

With carbon dioxide levels in the atmosphere hitting a record high, reducing the amount of gas in the atmosphere is more necessary than ever. Human generated climate change made flowers bloom sooner and autumn leaves fall later, turned some polar bears into early breeders. Hundreds of previous studies have confirmed that there is a vast change in the climate during the late few decades and it this the right time that world researches should collectively focus their attention to save the planet earth. Therefore worldwide researchers are working to reduce the carbon emission into the atmosphere. Automobiles are one of main sources of emitting Co2 into the atmosphere. Usually vapour compression refrigeration system is employed in automobile air-conditioning. In the present system the compressor derives power from the engine, resulting in a higher power engine and the exhaust gas pollutes the atmosphere. The exhaust gas temperature from automobile engine is approximately 300 C. This heat can be used to operate the vapour absorption system. Utilization of waste heat from the automobile exhaust, lesser power consumption from the engine and noise reduction are few of the salient features of this project. In this project a feasibility study to design an automobile air conditioner using Li-BR – Water absorption system is carried out and reported. Design calculations are presented. Commercial aspects of this project are briefly summarised.

Key words: - Refrigeration system, Vapour Absorption system, COP, Waste heat, Global warming, air- conditioning, Generator, absorber.

Dear Dr.Ramaswamy,

Thank you for your response. I am living in Malaysia, but am at present in India working on a project.

My Malaysian country code is 60 and area code 7.

My mobile number in India is 9847144444. I would love to hear from you.

Thank you

Regards

Dr.Chandran

Just a thought, but maybe, this would have been best as PM's (Private Messages)

All this information now available for everyone on the net to use, and abuse :P

will u pls send me the details.

i am a b-tech student.this is for doing my project work

Hello Sir,

I am Lokesh Jeswani a B.E in Mechanical.

Just read your view on exhaust gas utilization to do air conditioning.

Just have a small doubt.

Is it there any device to store the power when the exhaust gas not sufficent(at no load condition ) to provide the required power to Li br absorption system.

Thanks in advance

Thanks and Regards

Lokesh Jeswani

Dear Sir,

Please request you to do let me know are we have any practical application (vehicle) using this Air conditioning automobile using heat of exhaust by Vapor absorption system

I ama Canadian and moving ahead with the development of a vehicle air conditioner, it shall be applied to Buses, Cars and Vans. It shall use the exhaust from the manifold. Ammonia gas is suitable as the winters are harsh. Middle East and tropics can use other efficient heat absorbers.

The same principle is being developed for our homes in the tropics. Having a respectable heating and cooling by the sun heating techniques ( Solars )

Hello Sir,

I am Lokesh Jeswani from India.

Thanks for providing information.

I am actually interrested in the total size of the components .

Like generater, absorber,condensor, evaporater etc.

Is it there any practical application (Please specify the name of vehicle and Brand)

which is currently using this system.

Please request you to provide the detail size of each component if possible.

Thanks for your corporation .

Reagrds

Lokesh

Why use the Exhaust from the manifold, and not the water from the radiator?

If you cool the exhaust (I guess thats what your doing) then your trying to move a more dense medium down the exhaust system.

If you use the heat from the radiator, then your cooling the liquads that the radiator is trying to do normally.

Hello,

Briefly scouring the internet, I found one potential for an ammonia absorption refrigeration system for automobiles in the Journal of Energy in Southern Africa titled "A Car Air-conditioning System Based on an Absorption Refrigeration Cycle using Energy from Exhaust Gas of an Internal Combustion Engine"

Hope this helps.

SIR

WE ARE WORKING ON THE PROJECT OF Air conditioning automobile using heat of exhaust SO I WANT SOME GUIDANCE AND DO SOME MORE EXPERIMENT ON THIS PROJECT SO KINDLY PROVIDE ME YOUR EXPERIENCE ON IT.

THANKING YOU.

Hello Sir,

I am Lokesh Jeswani a B.E in Mechanical.

Just read your view on exhaust gas utilization to do air conditioning.

Just have a small doubt.

Is it there any device to store the power when the exhaust gas not sufficent(at no load condition ) to provide the required power to Li br absorption system.

Thanks in advance

Thanks and Regards

Lokesh Jeswani

currently I have no knowledge of anyone coming up with such devices, but incorporating a turbine and coupling it with a bicycle dynamo, you could charge your battery but a small circuit has to be placed to distribute it in a 12 volt recharger.

sir,iam Ganesh doing my final year in mechanical engg,i want your project report sir.plz forward ur report to my Email-id[ganes3@gmail.com]

Dear Mr.Ganesh , I did this project 28 years ago. I gave my copy to one of the students long ago and he has not returned back. I am sorry. If I can help in any other way I will do it. All the best for your project work. Regards, Dr.Ram

its ok sir. do u know where to get the Li Bi unit. give me your suggestion for this. i am planing to buy this unit.Now we are doing Thermal Storage device using PCM to store the heat in no load condition,if you give the details of input temperature given to Generator it helpful to me.Thank you for ur reply for the previous message sir.........

The idea seems to be pretty nice but i have only one doubt if this system can be designed and made to work then why nobody has started manufacturing cars with this system till now??

This is good question the constrains are :-

1. size of VARS

2. the set up cost.

It is not easy to store such asystem in small cars etc as system size is a big constrain.

Hello, I was researching this exact idea all week. It started out as an air to water inter-cooler design for my turbo charged racing car. Then I realized my RV uses propane to run the refrigerator. So why not use the same process for an intercooler? Better yet an air conditioner!

I thought that it was definitely a patentable process, did a search and of course some one had patented it from Taiwan in 1996. # 5,537,837. I am surprised it hasn't been implemented in vehicles today. My thoughts are it was either costly or too complex for the automotive industry. I could not find any related studies or attempts to achieve this idea.

Has there been any tests or prototypes?