Why is the Quasiturbine superior to conventional turbine ?

At the bottom of electrical water dams, in steam boiler, in pressurized gas reservoir, as well as in fuel mixture combustion, the energies are all initially under the form of "potential pressure forces". 

The conventional TURBINE (hydro- or aerodynamic) : 
The conventional turbine is a continuous flow engine at intake and exhaust. As the conventional turbines do not convert the pressure forces but rather the kinetic energy of rapid flows, it is then first necessary to convert the pressure forces in high speed flows by a channeling or by oriented expansion. This intermediary conversion is particularly complex and not without energy lost, specially due to viscosity, turbulences, and some time thermal conduction of hot gases. The conventional turbine is generally located where the flow is the fastest. On the other hand, the conventional turbine cannot convert in mechanical energy all the kinetic energy in the flow, so that it is often suitable for efficiency improvement to have other succession of turbine stages, which increases the complexity. In many applications one has flow velocity near the sound speed where any instability, impurity or condensate may damaged the turbine, which consequently requires well trained operators. Finally, as explained at the section referred below "Quasiturbine - Comparative efficiency  with other engines", the conventional turbine is the engine which requires the highest gas flux (and consequently the highest consumption) just to maintain its free operational RPM (without producing any net energy), explaining why they are so fuel inefficient when not producing their full power. The conventional turbines are however well adapted to aeronautical applications, but have others limitations which the Quasiturbine does not have :

- The efficiency decreases generally as the size (power) of the turbine is reduced, due to the relative increase of thermal effect, turbulences and viscosity. A characteristic which limit the potential of low power turbine. 

- The conventional turbines have a very narrow regime of efficient power, which is defined at design by the selected flow condition. They are not suitable for vehicles propulsion by example. 

- They present the inconvenient to rotate at very high speed and to require costly and sensitive gearboxes to increase their torque. 

- They do not tolerate any operation error.

- Because they use important and very fast flows, they are noisy and very sensitive to dusts, which after acceleration hit hard on the blades.

- Reversible and bi-directional. The aerodynamic shape of the blades does not permit conventional turbine to reverse the flow direction. The Quasiturbine is efficiently reversible (by motorizing, it becomes a pump) and bi-directional (in inverting the direction of the flow).

The QUASITURBINE (hydro- or aerostatic) : 
As the conventional turbine, the Quasiturbine is a continuous flow engine at intake and exhaust. However, the Quasiturbine is a turbine which turns under the effect of static forces and does not make use of hydro- or aerodynamic flows properties. Consequently, the Quasiturbine convert the potential forces directly into mechanical energy, without first going through the intermediary conversion in rapid flows required by conventional turbine. Notice that in pressurized fluid converter mode (pneumatic, steam...), the fluid (liquid or gas) pushes at relatively low speed in the Quasiturbine, without expansion (we exclude here the internal combustion mode). The expansion occurs only at the end of each 90 degrees angular displacement, once the pressure force has already been converted to mechanical energy. This property reduces considerably the interest of successive units and permit a much better control of residual exhaust energies which are rather thermal than kinetic, and to recover heat more efficiently when suitable. Because the Quasiturbine operates under the effect of static forces, it can not be damaged by saturated steam, neither by small impurities in the fluid flow. The Quasiturbines have consequently 4 interesting characteristics :

- The efficiency stays constant and optimum no matter the size (power) of the unit.

- For a given unit, the operation efficiency is optimum on a wide power range.

- They have the advantage to rotate at low speed and to produce a strong torque.

- They do not mind most operational errors.

The MICROTURBINES :
We hear a lot about distributed electricity production by microturbines. As the efficiency of those small units is inferior to large conventional plants, the operating cost and total pollution volume are consequently superior (Notice that the combustion of natural gas - methane - produces relatively few pollution, no matter what engine is used). To attenuate this debate, the microturbine manufacturers generally avoid discussing the efficiency of their microturbines, but rather mention the combined efficiency of 50% to 70% when used with thermal combined applications. They are not wrong, but every one must know that technologies of all kind can also incorporated the same way the thermal cascade applications to increase the global efficiency (... and not only the microturbines, which have certainly a good raison d'être as backup or security power plant).

See also:
Quasiturbine - Comparative efficiency with other engines
http://quasiturbine.promci.qc.ca/QTEfficaciteComparative.html

Quasiturbine Agence Inc., Promotional Agent for the Quasiturbine Continuous Combustion Rotary Engine or Compressor
Casier 2804, 3535 Ave Papineau, Montréal Québec H2K 4J9 CANADA (514) 527-8484 Fax (514) 527-9530
http://quasiturbine.promci.qc.ca             quasiturbine@promci.qc.ca