Micro Organic Rankine Cycle

[Aurel STDL]

This is my basic micro ORC concept to be developed as DIY project.

www.scoop.it/t/organic-rankine-cycle
www.microgenerationconcepts.com/

ORC converts low temperature heat to mechanical work for generatig elecricity.
The simple ORC consists from 5 basic components: see below.


E-HX - Evaporator heatexchanger
TEX - Turboexpander
G - Generator
C-HX - Condenser heatexchanger
P - Pump

[LowGear]

Do they work?

Will they harvest heat from the sun?

Do you have a KISS link?

Casey

[Aurel STDL]

Just one prototype was tested an year ago. It reached the working temperature and pressure but the turbine did not achieve sufficient power to spin generator.
It is designed for 65 Watt output power and it is realy needed to design and produce very precise micro turbo expander.

It is designed to convert heat from boiler or thermal solar colectors to mechanical work and generate power.

www.scoop.it/t/organic-rankine-cycle
www.microgenerationconcepts.com/

See picture below
Micro TEX 65W (Micro turbo expander, 65 Watt)

[Aurel STDL]

I have got more information regarding working temperature and pressure of that ORC.
See link below.

http://www.slideshare.net/MicrogenConcepts/organic-rankine-cycle

[millman56]

Does it use ammonia as the working fluid ?
Mark.

[Aurel STDL]

Ammonia is a typical fluid for Kalina cycle. It can work also with ORC but there are more enviromental friendly fluids on  the market.
Most common and ecological refrigerant is R134a. It is used in most car aircondinditioning systems, available and inexpensive.
It has also sufficient thermodynamic properties to use it for this purpose.
Probably the most disadvange is the reguirements for leaking of the system.

See the working pressure and teperature here:
http://www.slideshare.net/MicrogenConcepts/organic-rankine-cycle

[Aurel STDL]

http://www.scoop.it/t/turbines
Here are some interesting information which I am following about turbines design.

[Aurel STDL]

A picture below shows concept of counterflow heatexchanger.
This represents basic design of evaporator and condenser. Also it is designed to simple make it.
http://www.scoop.it/t/organic-rankine-cycle

[Henry W]

Hi Aural STDL,

There are others here that will want to ask lots of questions so please be prepaired to answer them.

A person working with refrigerant gasses under high pressure that this system needs to operate calls for a CFC type II or Universal certification.
The prohibition on venting HFC-134a has been in effect since November 1995 And if anyone violates any laws it is a hefty fine in the neighborhood $37,500.00 for the first offence What is intresting is people go into automotive stores and is able to purchase R134a. Most are clueless of proper proceedures and what they can be held accountable for by venting R134a. I would not recommend anyone here to get involved in a project like this unless they had the proper training and are certified.
Another thing is licensing for home use. I think it would be hard to have it approved. Than insurance.


Getting or making an effecient turbine is not cheap. But who knows what will be available in the future.

Overall it will be an intresting what other members think and comment about ORC.

Henry

[Aurel STDL]

Hi hwew,

thanks for your reply and arguments regarding refrigerant R134a. As you wrote the R134a is available everywhere and cheap. Many services are able to charge it. But some other specific working fluids for ORC  are available. I would prefer Solkatherm ES 36. This is not available as r134a and it is also much expensive, but it has properties more sufficient for this purpose.

[Aurel STDL]

http://sco.lt/5wEMq1

See the link over. This is an article why is the ORC a perspective energy "recovery" system.
It also argue that it is cheap and economic.
But the micro scale version with around 50-100 watts nett output power is not so economically recoverable.

That is the reason I am trying to create an DIY system.

[Henry W]

Most members here would would be looking for at least 3000 watts.

[Aurel STDL]

http://sco.lt/6Uug65
>3000 watts is power to supply whole family house. What to do with the heat produced in spring, fall or summer time. I am thinking about sistem what is able to supply necessary accesories like lights during the blackout. The most important accessories are circulating pumps of the heating system during the winter time. They can by supply by micro power plant and whole heating system can be independnt from public network.   

[Derb]

Looks like a simplified version of an Ormat N-Pentane power plant. We use them in NZ for energy recovery from geothermal brine wastewater from geothermal steam turbines. Pentane is pretty volatile stuff though.

[Henry W]

Aurel STDL,

The bottom line here is:

1. Generating enough power to operate equipment and appliances in homes.

2. Getting it approved by Underwriters Labratories, Insurance Companies, States and Counties, ect-ect to operate in homes.

3. Cost

There is no small efficent turbine available at this time for home use.
The issue is making a turbine that is small enough that will operate for this application. The biggest factor is cost. No one here would want to invest a large fortune to make something that will put out very little power.

Who will make a turbine for this application and what will it cost? Unless you know or have e team of engineers that designes turbines for a company that have the tooling to manufacture them, and you or others have the resourses and ability to do research and testing.

These issues need to be addressed. In the future it might be feasable but right now it will be very expensive. Solar panels are getting cheaper but it is still not cost effecive for most.

We are 100% electric and our electric bill is around $120.00 a month year around. right now I can live with this cost. Others are not so lucky so an alternate source can be helpful to lower utility costs.

Keep us posted if something works out. It would be nice to see progress in differant alternate energy producing systems.

Henry