This invention relates primarily to a combined turbine and rocket engine that implements the Carnot cycle. The combined turbine and rocket engine, also termed a turbine-rocket or turbo rocket, is designed to provide a highly fuel-efficient propulsion system for high altitude flight where available oxygen diminishes to levels where rocket propulsion with supplemental oxygen is required. To accommodate different levels of oxygen availability from atmospheric, where oxygen is freely available, to space, where oxygen is absent, new engine designs are required.
The Carnot cycle has been considered an ideal thermodynamic cycle maximum theoretical efficiency. However, the real Carnot cycle has not heretofore been implemental in a physical embodiment that effectively follows the four phases of the cycle. As indicated in the cycle diagrams included in this specification, the real thermodynic Carnot cycle includes the following four basic phases in a T-S (temperature-enthalpy) diagram:
The rocket engines of this invention incorporate the Carnot cycle and are represented in several different embodiments. Many of the component elements of the specific embodiments of the turbo rocket engine are derived from prior turbine engine designs and turbojet engine designs of this inventor.
The turbo rocket engine of this invention is designed to incorporate the real Carnot cycle into physical embodiments, primarily for high altitude propulsion. In addition, the embodiments of the turbo rocket engine define propulsion systems for aircraft that are operable in atmospheric and stratospheric conditions at maximum efficiency. Certain embodiments of the engines omit the turbine component and other embodiments are adapted for power generation. The engine cycle is by definition a universal Carnot cycle that is advantageous for air and near space propulsion.
High efficiencies are achieved by use of a ram air intake to enhance compression and drive associated air turbines that operate a counter rotating axial compressor for ultra high compression of combustion air. Where altitudes cause a diminishing supply of air, the process is supplemented by liquid oxygen supplied in progressive proportions.
Referring to
In the turbo rocket engine 10 of the figures, there is typically a central core 12 with an outer housing 14 with an intake opening 16 and a discharge orifice 18, with a complex of passages from intake opening 16 to the discharge orifice 18 that generates the unique cycle of operation.
In the engine embodiment 20 of
Centrifugal compression of air in the hollow core 21.2 of the air turbine blades 21.3 is cooled by the cold by-pass air around the blades which usually has a 5-20 by-pass ratio over air funneled through the air-turbine rotor 21 and hollow struts 22, which function as an intercooler between the centrifugal and axial compressors to further cool the centrifugally compressed air. The intensive cooling of the centrifugally compressed air results in an isothermal compression indicated in
The staged axial compressor 19 is provided with alternating counter rotating, outwardly directed blades 21.a-21.f, and inwardly directed blades 24.a-24.f to produce a polytropic (adiabatic) compression indicated in
Isothermic-stoichiometric combustion and expansion represented by phase 3-4 in
The majority of the intake air flows through the engine 10, by-passing the compressor apparatus except to drive the hollow blades 21.3 of the air turbine rotor in one direction and the fan blades 23.1 of the fan turbine 23 in the opposite direction.
Air that is highly compressed in the centrifugal and axial compressors from the phase 1-2 and 2-3 points, is divided into two flows 3.a and 3.b as shown in the enlarged schematic of
The variable volume intake control 27 regulates the high volume of the by-pass air flow 28-29 and the compressor air flow, and regulates the angularity of the prewhirl air at the entrance to the engine 10. The ram compressed, by-pass air mixes with the combustion gases for a final heated expansion through the discharge orifice 18.
The combustion process can be stoichiometric, since the products of combustion do not drive a turbine for compression but expand in a combustion-staged nozzle, producing a maximum power density.
For high altitude flight, ram air can be supplemented by liquid oxygen injected by one or more nozzles, similar to the fuel injection nozzles 30 and 31. Oxygen is added to the air stream in progressive proportions as available high altitude air diminishes.
In
In the engine embodiment 50 of
The final adiabatic expansion 4-5 closes the total real Carnot cycle. In parallel with the internal Carnot cycle, the ram compressed by-pass air proportionately provides greater thrust and is enhanced at higher elevations by liquid oxygen injectors 58 at the intake 16, and liquid hydrogen or liquid natural gas injectors 59 at the final mixing nozzle 57 before the discharge orifice 18, extending a combined cycle phase from 4-5-6 with a final adiabatic pressure-temperature expansion from phase points 6-7.
At very high speed, the energy of the ram air drives the centrifugal compressor 51 and counter-rotating air turbine 23, and the power required for the gas turbine 54 diminishes. To prevent over rotation, the peripheral combustion chamber 26 has a variable opening valve 55, which regulates flow through the gas turbine 54 by diverting the gas flow directly into the by-pass flow 29 for mixing and discharge through the discharge orifice 18.
Referring to
Using the multiple compressor stages, including the axial compressor 19 with counter rotating blades driven by centrifugal compressors 51 and 62, pressure ratios over 100 can be created and the efficiencies of the modified Carnot cycle maximized as shown in
At high speed, the ram air will raise the pressure ratios for precombustion at 3.2, followed by isothermal combustion 3.2-4, constant pressure combustion 4-5 and maximum stoichiometric combustion 5-6 and final expansion 6-7.
Referring to
The high pressure compressed air is supplied to a combustion chamber 71 with central fuel injectors 72 and staged fuel and air injectors 73 along the venturi section 75 with a variable geometry nozzle control 74 to regulate expansion. The liquid oxygen injectors 58 and liquid hydrogen or liquid natural gas injectors 59 provide supplemental oxygen as needed and added thrust for the final expansion in the mixing nozzle 57 before ejection from the discharge orifice 18.
Again, with the additional three stages of combustion, the Carnot cycle is extended from 3.2-4-5-6-7 for maximized power and efficiency.
Although embodiments of the turbo rocket engine that omit a gas turbine can easily operate at the stoichiometric level of fuel combustion, those embodiments including a gas turbine operate most efficiently with cooling of the rotor and stator blades to achieve stoichiometric levels.
Referring the FIGS. 8 to 10, a design for internal and external cooling of the blades of the gas turbine 54 of
Referring to
In the gas turbine engine 110 of
Additional cooling is provided by water or fuel injection into and through the blades of the turbines as described with reference to
The double process of evaporative cooling of the combustion chamber walls and the air and super fine spray of vaporizing fuel into the multiple stages of the gas turbine 123 permits a complete process of combustion at stoichiometric levels. The controlled maintenance of the maximum pressure at part loads maintains the cycle efficiency and the lowered pressure and consequently lower efficiency at part loads, typical of the Brayton cycle.
Referring to
The first assembly includes a centrifugal two-stage compressor 236 with a first isothermal stage central rotor 141 surrounded by a second adiabatic stage, counter rotating peripheral rotor 142 driven by the electric motors 143 and 144, respectively.
A series of water injectors 145 spray cooling water into the central compressor rotor 141 proportional to the compression level to generate a polytropic-isothermic effect for cooling the first stage compression. This phase is indicated on the T-S diagram of
A second assembly is formed by a gas turbine 146 with isothermal combustion. The gas turbine 146 drives the electric generator 237 by shaft 238. The gas turbine 146 is similar in construction to the gas turbines in
The third assembly is formed by an axial, polytropic, adiabatic power turbine 147 which drives the electric generator 148 by the shaft 149. Controlled injection of water into the turbine blades 234 and stators 239 allows the gas turbines 146 and 147 to maintain temperatures that are consistent with the temperature limits of the materials of the turbines.
The exhaust of the gases and final expansion completes the cycle from phase points 4.2-5 and 5-1, closing the cycle.
The universal thermodynamic gas turbine cycle, as depicted in
Also, at full load including the isothermal-stoichiometric phases of the cycle 1-4.1, 4.2-5.1-1, a maximum power can be generated. For comparison, the Brayton cycle 1.a-2a-4.2-5.1-1 and diesel cycle 1a-2.a-4.a-5.a-1a are included in the diagram of
Referring to
The ram-jet rocket engine 150 has an outer body 151 having a variable geometry intake port 152 regulated by an intake control valve 153. A central primary combustion chamber 155 is followed by an expanding multi-stage isothermal combustion chamber 156 of the type described with reference to
The configured engine 150 of
As illustrated in
Referring to
A series of multiple conical venturi nozzles 198 of increasing size with accompanying staged fuel injectors 199 form an injection cascade of fuel and cryogenic oxygen through the nested windows 200. The isothermal combustion and expansion continues to the final ejection nozzle 201 where the adiabatic expansion within the cooled walls 202 provides final propulsion in a nozzle structure that is sufficiently cooled to allow for stoichiometric combustion. In this manner, by definition, the motive gas flow has a maximum density providing a super powerful reactive mass flow for propulsion.
The successive addition of new heat energy to the central adiabatic flow produces an isothermal Carnot cycle stage to maintain the outer nozzle structure within thermal limits until the final adiabatic expansion in the discharge nozzle 201.
Referring to
In the embodiments of
The gas turbine 170 is configured with the annular combustion chamber 171, into which compressed air from the staged high pressure compressors is delivered with a toroidal swirl for complete mixing and combustion. By measured injection of water, the combustion chamber and expansion in the turbine is isothermal with staged entry of the motive gases by the window features as previously described with reference to
The torroidal rotation of the air and fuel around the gas turbine 170 produces the maximum mixing and complete combustion even for heavy, inferior fuels.
From the high pressure chamber 178, an exhaust pipe 172 conveys the medium pressure motive gases to a medium pressure combustion chamber 173.
In the medium pressure combustion chamber 173, the motive gases are introduced with a torroidal swirl where fuel may be added through staged injectors 179 for the isothermal gas turbine 163 before final expansion through an adiabatic power turbine 74 and exit through a discharge nozzle or conduit 175.
In a preferred configuration, the power turbine 174 drives an electric generator 176.
As diagramatically illustrated in
Isothermal ultra high combustion and expansion indicated by phase points 4-5 is produced in the isothermal combustion chamber 171 and isothermal gas turbine 170.
Isothermal medium combustion and expansion with torroidal swirl is indicated by phase points 5-6 and produced in the combustion chamber 173 and gas turbine 163.
Final adiabatic expansion indicated by phase points 6-7 is produced in power turbine 174.
While, in the foregoing, embodiments of the present invention have been set forth in considerable detail for the purposes of making a complete disclosure of the invention, it may be apparent to those of skill in the art that numerous changes may be made in such detail without departing from the spirit and principles of the invention.
This application relies on the priority of the following provisional applications: U.S. Provisional Application Ser. No. 60/466,270, filed Apr. 28, 2003, entitled, “Turbo Rocket with Real Carnot Cycle;” U.S. Provisional Application Ser. No. 60/470,706, filed May 15, 2003, entitled, “Turbo Rocket with Real Carnot Cycle and Transpiration Blades;” U.S. Provisional Application Ser. No. 60/486,637, filed Jul. 11, 2003, entitled, “Turbo Rocket with Real Carnot Cycle Continued;” U.S. Provisional Application Ser. No. 60/507,400, filed Sep. 30, 2003, entitled, “Turbo Rocket with Real Carnot Cycle Continued Second.”
Number | Date | Country | |
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60466270 | Apr 2003 | US | |
60470706 | May 2003 | US | |
60486637 | Jul 2003 | US | |
60507400 | Jan 2004 | US |