RU2131529C1 - Swirl-chamber turbo engine - Google Patents

Abstract

FIELD: gas-turbine plants using regeneration and isobaric supply of heat. SUBSTANCE: engine has combined compressor and turbine wheels shaft-mounted in casing and separated by heat-regenerating wall, as well as continuously acting combustion chamber and two impellers mounted on shaft between combined compressor and turbine wheels for axial displacement to compensate for thermal expansion of wheels. One of impellers used for auxiliary compression of heated gas has larger radius. Other impeller designed for dynamic release of compressor and turbine wheels in radial direction has smaller radius. Both impellers separate combustion chamber from engine shaft. Casing is built up of two halves with vertical split joint and accommodates, in addition, contraction with variable-section helical taper flow passages. EFFECT: improved power capacity and efficiency of engine. 5 dwg

Description

 The invention relates to internal combustion engines.

 As analogues of the invention, the following devices can be considered.

 Vortex machine. V.D. Lubenets, V.N. Khmara, I.Ya. Sukhomlinov, M.A. Radugin, N.A. Smirnov, L.N. Belotelova. A. s. 306282, USSR. Stated 01/13/1970 (N 1398122 / 24-6), publ. 06/11/1971 (Bulletin No. 19), UDC 621.515 (088.8). IPC F 04 D 23/00.

 Single-stage supercharger 6400-11-1 of the NZL design with double suction. F. M. Chistyakov, V. V. Ignatenko, N. T. Romanenko, E. S. Frolov, book "Centrifugal Compressor Machines", publishing house "Engineering", Moscow, 1969

 Centrifugal compressor of a VK-1 turbojet engine with two-sided input. K.P. Seleznev, Yu.S. Podobuev, S.A. Anisimov, book "Theory and calculation of turbocompressors", publishing house "Engineering", Leningrad, 1968

 Gas turbine unit (GTU) with regeneration and isobaric supply of heat. V. I. Krutov, book "Technical Thermodynamics", publishing house "Higher School", Moscow, 1991 (pp. 289-293).

 The method of operation of an air turbocharger with a steam turbine drive. G.S. Rastorguev. A.S. 85063A, USSR, IPC 6 F 04 D 25/02, 1959.

 Jet augmenter for combustion turbine propulsion plants. F.A.M. Heppner. US 2,430,399, cl. 60-264, 1947.

 As an analogue (prototype) closest to the claimed invention, Jet augmenter for combustion turbine propulsion plants (US 2430399) can be distinguished.

 The characteristic, essential features of the analogue (prototype) and the claimed invention are the presence of a turbocharger that provides operating pressure in the combustion chamber; continuous combustion chambers, where the mixture temperature rises at constant pressure; a working turbine, where the potential energy of the gas mixture is converted into the kinetic energy of the rotor rotational motion with expansion and lowering of the gas temperature in the interscapular channels. The prototype scheme works on a cycle of gas turbines with regeneration and isobaric supply of heat. The gas passing through the working parts of the turbine and discharged into the environment has a higher temperature than the air entering the combustion chamber after compression in the compressor. This allows you to use the heat of the flue gases to preheat the air before feeding it into the combustion chamber.

 The invention is aimed at solving the problems of reducing hydraulic losses during gas flow in the channels of the compression and motor wheels, in the channels of the confuser, providing gas inlet to the turbine blades; increase in operating pressure and torque on the engine shaft due to the vortex effect of the gas flow on the turbine blades; increase engine power and efficiency.

 The proposed engine operates on the scheme of gas turbines with regeneration and isobaric supply of heat.

The essential features of this device include:
1. The presence of rotating and stationary screw channels in the impeller of the compressor, in the turbine and in the confuser, creating a gas flow in the form of a helical vortex as a flow with the least resistance, which is confirmed by natural analogues:
draining water through a cylindrical neck with the formation of a helical vortex in the form of a funnel;
tornado-helical vortex between zones with different pressures;
the range of a bullet from a rifled weapon is greater than from a smoothbore.

 2. An increase in torque and power on the motor shaft due to the swirling effect of the flow on the turbine blades.

 3. The combination of the impeller of the compressor and the turbine in the radial plane in order to ensure regeneration through the wall separating the channels of the compressor and the turbine, instead of using a separate heat exchanger.

 4. Transfer of torque from the turbine of the impeller to the shaft through the compressor part, rigidly connecting the turbine and the motor shaft.

 5. The presence of two impellers between symmetrically arranged wheels, one of which (a larger radius) provides additional compression of the heated gas, the other (a smaller radius) provides dynamic unloading of the impellers in the radial direction, and together these impellers reduce the thermal effect of the combustion chamber products on the engine shaft .

The features of the design include the following elements of the device:
a wheel, the distinguishing features of which include the fact that it as a whole integrates in a radial plane the impeller of the compressor and the turbine; has screw conical flow channels of variable cross-section both in the compressor part and in the turbine part;
a confuser, the distinguishing features of which include the fact that it has helical conical channels that accelerate gas along a helical path and provide a vortex effect of the gas flow on the turbine blades;
a system of two impellers of compression (larger radius) and unloading (smaller radius), the distinguishing features of which include the fact that they are located between the impellers, from which torque is transmitted to them; has the ability to move along the axis of rotation to compensate for temperature deformations of the wheels; separates the combustion chamber and the engine shaft, protecting the latter from thermal effects.

 FIG. 1 - thermodynamic cycles of a gas turbine engine and a turbo-vortex engine in the (V-P) diagram.

 FIG. 2 - thermodynamic cycles of gas turbine engine and turbo-vortex engine in (S-T) diagram.

 FIG. 3 - scheme of gas turbines with regeneration and isobaric supply of heat.

 FIG. 4 is a design sketch of a turbo-vortex engine.

 FIG. 5 is a sketch of the constructive use of the system of two impellers.

 The possibility of carrying out the invention is considered on the design of an engine running on any liquid fuel supplied through a nozzle to a continuous combustion chamber.

 A qualitative thermodynamic analysis of the operability of a turbo-vortex engine with thermal efficiency adequate to the thermodynamic efficiency of a gas turbine is shown in the (VP) (Fig. 1) and (ST) (Fig. 2) diagrams, which show in comparison the thermodynamic cycles of a gas turbine with regeneration and isobaric supply of heat and turbo vortex engine.

A cycle of a gas turbine installation (GTU) with regeneration and isobaric supply of heat, a diagram of which is shown in FIG. 3, consists of the following thermodynamic processes: in the compressor, the air is compressed adiabatically (process 1-2), after which it enters the heat exchanger, where it is heated by exhaust gases at constant pressure (isobar 2-8). Heated air is supplied to the combustion chamber, where the heating of the working fluid continues at a constant pressure due to the heat q ₁ coming from a hot heat source, i.e. due to the heat released during the combustion of fuel (isobar 8-4). Then the gas expands adiabatically in a gas turbine (process 4-5), enters the heat exchanger and gives off heat to air at constant pressure in the isobaric process 5-7. Further isobaric cooling 7-1 occurs outside the unit due to the transfer of heat to the environment.

With complete heat recovery T ₃ = T ₇ and T ₅ = T ₈ , therefore T ₅ - T ₇ = T ₈ - T ₂ . The specific heat supplied in the presence of regeneration to the working fluid in the combustion chamber is q ₁ = c _p (T ₄ -T ₈ ) given to the cold heat source q ₂ = c _p (T ₇ - T ₁ ), therefore, the thermal efficiency of the cycle with complete regeneration
η _t = 1 - (T ₇ - T ₁ ) / (T ₄ - T ₈ ) = 1 - T ₂ - T ₁ ) / (T ₄ - T ₅ )
Since T ₂ = T ₁ ε ^k-1 ; T ₄ = T ₁ ρ _v ε ^k-1 ; T ₅ = T ₁ ρ _v , then η _t = 1 - 1 / ρ _v = 1 - T ₁ / T ₅ (which is true for the cycle under consideration), where ε = V ₁ / V ₂ is the compression ratio, ρ _v = V ₄ / V ₂ - the degree of preliminary expansion.

 But in reality, regeneration cannot be complete, and therefore, the real value of thermal efficiency will be somewhat lower.

The turbo-vortex engine cycle involves regeneration not in the heat exchanger, but through the wall separating the compressor and turbine channels. In this case, air compression (process 1-8) proceeds with the supply of heat, i.e. with a polytropic exponent n> k. This leads to a decrease in the compression ratio ε = V ₁ / V ' ₈ , but then the degree of increase in pressure increases λ = P' ₈ / P ₁ . Heat supply during fuel combustion (process 8'-4 ') will be carried out at a higher energy level. The gas mixture from the combustion chamber, accelerating in a confuser with conical screw channels, enters the turbine blades in the form of a helical vortex, where there is an expansion of the flow, accompanied by a vortex action on the turbine blades and heat recovery (process 4'-7). In this case, the turbine does a positive job (area 4''4'77 ', Fig. 1), spent by the compressor on compressing fresh air (area 7'18'4'', Fig. 1) and overcoming the payload l _c (area 18'4'7, Fig. 1 - work cycle). Further isobaric cooling 7-1 occurs outside the unit, similar to a gas turbine.

The specific heat supplied in the presence of regeneration to the working fluid in the combustion chamber is q ' ₁ = c _p (T' ₄ - T ' ₈ ) = c _p (T ₄ - T ₈ ) = q ₁ given to the cold heat source q ₂ = c _p (T ₇ - T ₁ ), therefore, the thermal efficiency of the turbo-vortex engine cycle will correspond to the thermal efficiency of the gas turbine cycle with full regeneration
η _t = 1 - (T ₇ - T ₁ ) / (T ' ₄ - T' ₈ ) = 1 - (T ₇ - T ₁ ) / (T ₄ - T ₈ ).

Forcing the turbine to work from a higher pressure level (P ' ₄ ) and taking into account the significantly larger turbine blade area compared to the gas turbine engine, we can expect a corresponding increase in the amount of torque transmitted to the engine shaft, and therefore, engine power and efficiency.

 The engine design was developed in a preliminary design based on a typical kinetic compression compressor (application N 97108710 (009391)) and is presented in FIG. 4. In the proposed engine, the rotor is made in the form of a shaft 12 with impellers mounted on it, consisting of compressor 13 and turbine 14 parts, with helical conical channels. Two impellers are installed between the wheels: compression 15 and unloading 16. The engine contains a housing made of two halves 17, 18, in which confusers 19, 20 are installed, having helical conical channels. Suction and exhaust pipes are located in each half of the housing. The vertical planes of the housing connector provide good shaft alignment and ease of engine assembly, as well as simplified lithium technology and machining of coaxial surfaces.

 The symmetrical arrangement of the wheels on the motor shaft provides dynamic axial balancing of the shaft. The shaft only accepts torque.

 The unloading impeller 16, creating a vacuum in the area between the compressor parts of the wheels, reduces the action of centrifugal forces and, therefore, reduces the pressure on the interface with the turbine part of each wheel.

 Due to the vortex effect of the screw flow coming from the screw blades of the confuser to the screw blades of the turbine, the potential energy of the compressed and heated gas mixture, as well as its kinetic energy, is converted into kinetic energy of the rotor, which is partially transmitted to the consumer, partially returned to the compressor stage.

 In FIG. 4 conventionally shows the direction of the blades of the confuser, compressor and turbine parts of the wheel, as well as the corresponding direction of rotation of the shaft. It also shows the direction of flow of gas mixtures along the working channels of the engine.

In FIG. 5 shows an embodiment of the system of two impellers: compression 15 and unloading 16. The torque from the impellers is transmitted to the impellers through pins 21. When assembling the rotor, an axial clearance (Δ) between the impellers and impellers is provided, which compensates for the temperature deformation of the wheels along axis of rotation. Due to the adequacy of the radial dimensions of the impellers and the corresponding sections of the impellers operating under the same temperature conditions, the tolerance of the running fit of the pins and adjacent surfaces of the impellers and impellers is sufficient to compensate for temperature deformations in the radial direction. Section (AA) explains the principle of operation of the system of two impellers. To explain the processes during the passage of the working fluid through each impeller, three regions are distinguished that differ in gas state parameters (P ₁ , T ₁ , P ₂ , T ₂ , P ₃ , T ₃ ).

The unloading impeller 16 provides a reduced pressure in the area of the shaft P ₁ <P ₂ due to the process of pumping a certain mass of gas from this zone. As can be seen from the velocity triangles, at the initial moment the gas enters the impeller blades with an absolute speed of C ₁ (U ₁ is the portable gas velocity, W ₁ is the relative gas velocity) and leaves the blades with an absolute speed of C ₂ . At the moment when C ₁ becomes equal to zero, and the pressure decreases to P ₁ , a circulation flow (vortices) will appear in the interscapular channels, which establishes a balance of the gas flow entering and leaving the shaft zone. A change in the number of shaft revolutions will shift this equilibrium state in one direction or another, changing the pressure value P ₁ accordingly. From the balance of forces (Fig. 5) on the wall of the compressor part of the wheel’s operation, it is seen how the centrifugal force (F _cb ) _decreases due to the pressure difference on the wall (P ₂ - P ₁ ).

The compression impeller 15 operates as a centrifugal supercharger, which compresses the gas from pressure P ₂ to pressure P ₃ , and does not require additional explanations.

 The engine should be equipped with a fuel pump, an electric motor-generator for unwinding the shaft at the time of start-up, a gearbox with a friction clutch to transfer mechanical energy to the consumer. The listed elements are somehow attached to the motor shaft. In addition, a fuel mixture ignition system is required.

Claims (1)

 A turbo-vortex engine operating on the basis of a gas-turbine installation with regeneration and isobaric supply of heat, comprising combined compressor and turbine impellers installed in a housing on a shaft having a dividing wall through which heat is regenerated, and a continuous combustion chamber, characterized in that the engine is equipped with two impellers mounted on the shaft between the combined impellers with the possibility of axial movement to compensate for the thermal expansion of the wheels, while one of the impellers has a larger radius for additional compression of the heated gas, and the other has a smaller radius for dynamic unloading of the impellers in the radial direction, both impellers separate the combustion chamber and the engine shaft, the casing is made of two halves with a vertical plane connector and it is additionally equipped with confusers with screw conical flow channels of variable cross-section.

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