How it works


The Prometheus Turbine works like a conventional gas turbine, but uses electrical heating elements to heat the air in its combustors. Please see pictures 1 to 1c. NB: pictures are not drawn to scale.

Picture 1: Flow chart of the Prometheus Turbine    

 

  Flow chart of the Prometheus Turbine

Picture 1a: Cross view of  Prometheus Turbine combustors

Cross view of the Prometheus Turbine

A = Air, B = compressors, C = combustors, D = electric heating element, E = axis connecting the compressor and the turbines driving them, F = turbines, G = turbine generator, H = walls made of insulating and heat reflecting material, I = thermo-electric generators which convert that might permeate the insulation and reflecting material (H) in to electricity.

Air is sucked in, compressed and send through the air-flow channels of the 120 cm long combustors (C) where it is heated to 1200 C by 7 kW electric heating elements (D).

The hot air expands and drives the turbines (F) of the compressors and the power generator (G) Axis (E). Also see picture 1b.

Picture 1b: cross-section view of a combustor fitted with electric heating element


Diagram of combustor with electric heating element

The number and diameter of the combustor and air-flow channels depends on the volume of air they have to take in. The sides of the space containing the combustor can be made to function as a reflector.

This way the air gets evenly heated from virtually all sides, and it saves energy.

Picture 1c



The combustor will resemble the receiver from an concentrated solar plant using the Brayton cycle. It is made of ceramics but also could made of metals already used in gas turbines.











Main advantages:


A thermostat controls the temperature inside the combustors, so there is no need for cooling air. All the air coming from the compressors can be fully heated and used to drive power turbine.

There is no flame to keep alive, so there is no need to slow down the air stream coming from the high-pressure compressor by using a diffuser.

Unlike in conventional combustors, the air coming from the compressors does not expand in the air-flow channels of an electric combustor. This means there is no loss of compression.

All of this will save electricity/energy and add more pressure on the turbines of the generator.


Picture 2 - nuclear reactor of Pluto ram jet

Nuclear reactor of the Pluto ram jet

Heating the air over a distance of 120 cm should be sufficient to heat the air to the same temperatures as in conventional combustors.

It is about the same distance the incoming air was heated passing through the nuclear core of the Pluto nuclear ram jet, which would have been capable of generating 500 MW.

Watch this Discovery Channel video on YouTube to learn more.




Picture 2a - Pluto ram jet


500 MW is enough power to fly the Pluto ram jet, weighing 27540 kg (60780 lb), at a speed of Mach 3 to 4.
 
Artist impression - Pluto nuclear ramjet in flight


Picture 2b - Flowchart Atomic Bomber


Image below is a screenshot taken from the Discovery Channel series "The Planes that never flew".

The reactor in this experimental plane based on a B52 bomber was even smaller.

Please watch it on YouTube It might help to understand how the idea is suppose to work.

Flowchart or the Atomic Bomber
A = air inlet. B = compressors. C = the compressed air is send to the nuclear reactor (D) where it is heated. The heated air (E) drives the turbine of the compressor and propels the Atomic Bomber (F).

Picture 2c - The real thing


Direct cycle atomic plane engine

Picture of the real thing depicted in the flowchart above.


Picture 3 - The combustors are basically fitted in a furnace


Open pot type furnace consumes only 84 kW
The type of electric heating element used in pictures 1, 1a and 1b is based on the Kanthal heating elements shown in picture on the left, depicting a open pot type furnace used for melting glass.

This type of heating element consumes 7 kW.

The 12 heating elements combined consume only 84 kW.

Temperature inside the furnace is 1300 Celsius.

Comparing the efficiency of a conventional and Prometheus Turbine


If you would replace each one of the eight combustors of a Kawasaki GPC 80 DLE gas turbine with an electrically heated combustor, capable of processing the same quantity of air, the amount of energy that might be saved is astonishing. Please compare pictures 4 and 5.

Picture 4

Fuel consumption Kawasaki gas turbine

The eight combustors of the conventional Kawasaki gas turbine in picture 4 consume 23492 kWh!

The 1000 kw diesel generator powering the eight electric combustors of the Prometheus Turbine in picture 5 consumes 2690 kWh!! (1000 kW is enough to power over one hundred 7 kW heating elements)

Picture 5

Fuel consumption Prometheus Turbine
This means it is perhaps possible to save 20802 kWh, it also means the Prometheus Turbine could be self-sustaining!

The Prometheus Turbine's output 7800 kW - 1000 kW for heating elements and starter engine gives a net output of 6800 kW.

However, even if each of the eight heating elements would consume 420 kW (enough to power 60 electric heating elements or 5 of the furnaces in picture 3), and the starter engine would consume 440 kW, the net output would still be 4000 kW.

Breaking the law?

Does the Prometheus Turbine conflict with the first law of thermodynamics / law of conservation of energy?

Yes, if you only take into account the direct use of energy (amount of fuel burned).

Meaning, why not also take into account the amount of energy that was used to find, drill for, refine, store and transport the fuel that is burned.

Or the energy costs of building the generator /turbine, energy used by the staff operating and maintaining the power plant, and constructing and maintaining the building housing the power plant?

If you also take into account the use of this indirect energy use, the Prometheus Turbine probably complies with the law of conservation of energy / first law of thermodynamics.

It’s not a perpetuum mobile, just a very efficient gas turbine.

A more extreme example:


Assembly of a Siemens SGT5-8000-H gasturbine<< The Siemens SGT5-8000H gas turbine, with 16 combustors, has an open cycle gross output of 375 MW* and a combined cycle output of 578 MW (using the hot exhaust air to generate steam).

If all of the 375 MW open cycle power would be used to electrically heat the air inside the 16 combustors, about 22 MW* of electricity per combustor, its gross output would still be 203 MW (578 MW - 375 MW) in a combined cycle configuration.

Please compare the combustor in the red square with the two engineers. Just imagine concentrating 22 MW of electricity in a combustor roughly the size of a oil drum.

Induction furnace capable of smelting 50 tons of steel

* 22 MW is a lot of power.

Enough to power 1 of these 22 MW induction furnaces (left picture) capable of smelting 50 tons of steel, which has a melting point of 1500 C.

Click picture for source.



Even if 577 of the 578 MW combined cycle output is needed to power the combusors, it probably still can sustain itself and supply the grid with 1 MW of electricity.

Most if not all nuclear fusion experiments like ITER haven't even been able to achieve breakeven point!

Btw, ITER is supposed to generate ten times the input. For some reason, the laws of thermodynamics don't seem to apply to nuclear fusion.

Efficiency of heating electrically


Using electric heating elements might seem inefficient, but is not. Electric heating elements convert 99% of the electric input into heat.

For instance, many energy intensive industries like the glass and ceramics industries, are replacing fossil fuel heated furnaces by furnaces heated by electric heating elements.

On Kanthal.com you can find many case stories in which companies achieved fuel cost savings of over 40%.

There are many examples of gas turbines which do not burn fossil fuel in order to heat air. For instance in a Gas-Cooled Fast Reactor (GFR) or in a Pebble Bed Reactor helium is heated by nuclear fuel elements.

Another good example is AORA's solar-thermal technology: concentrated sunlight heats ceramic tiles. Next, the hot ceramic tiles heat compressed air which drives the turbine of a generator.

Environment


In addition to the enormous reduction of fuel costs, there is also a considerable reduction of the emission of green house gases.

According to the online calculator of the US Environmental Protection Agency, the carbon dioxide equivalent of 20802 kWh is ± 14363 kilograms.