Gas generator
The present invention relates to a gas generator having a plurality of vibration chambers organized in a circle, cham¬ bers in which vibrating gas forms nodes of gas pressure and velocity.
The state of the art can be deemed to comprise various jet engines, as disclosed, for example, in US Patents 2,675,675 and 3,008,292. Finnish Patent Application 874918 also dis¬ closes a gas resonance device representing the state of the art. In prior-art gas generators of this type, operating ac¬ cording to the vibration principle, there are used, for feed¬ ing in the gas, flap valves operated by gas pressure; having a short useful life and causing flow resistance, these valves have prevented the gas vibration principle from being applied more extensively. The object of the invention is to provide a gas generator of a new type, without the known disadvantages. The gas generator according to the invention is characterized in that, in conjunction with the vibration chambers, the a is a valve block which revolves relative to the vibration cham¬ bers and by mediation of which the guiding of fresh mixture into the vibration chamber is arranged.
In the gas generator, the piston of the conventional piston engine is replaced with a gas column. The vibration of gas in the working chambers is staged in such a manner that the stage difference between the vibrations of adjacent working chambers is of the same magnitude as the angular difference between the working chambers. Thus the various stages of gas vibration appear evenly in the different chambers of the working-chamber group. The rotary valve piece lets in fresh gas always into that chamber or those chambers in which the gas pressure i„, low. This is comparable to the suction stroke of a convention¬ al piston engine. Since the valve, while revolving, opens con-
tinually into chambers having the same pressure, the flow of gas from the feed pipe into the working chambers is contin¬ uous, and thus also relatively free of losses. This is advan¬ tageous in terms of the efficiency of the engine. The gas col¬ umn vibrating in the chamber compresses to a compression pres¬ sure the fresh gas fed in at its end, and at this pressure the gas is ignited or it ignites spontaneously under the effect of the small amount of hot gases fed in by the adjacent chamber. Since the mixture of fresh gas and fuel is burned during the pressure peak, compressed, it considerably increases the in¬ tensity of the vibration, at a good thermal efficiency. In¬ tense vibration for its part sucks in new fresh mixture during low pressure, and thus the operation of the generator is con¬ tinuous.
One embodiment of the invention is characterized in that the valve block is a valve block revolving inside circular vibra¬ tion chambers, the valve block having on its outer circum¬ ference suction and exhaust slots opening into the vibration chambers so that the burned gas mixture is also controlled by the same valve block. By means of a valve such as this the outlet of gas from the vibration chamber can be controlled so as to be most advantageous in terms of the operation and ef¬ ficiency of the engine. By the use of a rotary valve a con¬ stant gas flow from the vibration chamber into the turbine is obtained, since the opening of the valve is continually engag¬ ing with new vibration chambers, but always at the same "work¬ ing stroke" , in which both the pressure and the velocity of the gas are the same.
Another embodiment of the invention is characterized in that the vibration chambers are elongate, conically widening tubu¬ lar or sectoral chambers and that the suction and exhaust slots of the valve block open into the narrower ends of the vibration chambers.
The claims further disclose more embodiments pertaining to the gas generator.
The advantages of the gas generator according to the invention include:
- no lubrication oil is needed in the gas generator, only a few permanently lubricated roller contact bearings are re¬ quired,
- there are no octane number requirements set on the fuel, and so there are no emissions of lead,
- immoderate quantities of nitrogen compounds are not formed, since the speed of combustion is high and the combustion tem¬ perature can be controlled by means of an excess of air so that a good compromise between efficiency and the purity of the exhaust gases is obtained,
- no coolant is needed, nor is a considerable cooling capac¬ ity,
- when the gas generator is used in an automobile, the power transmission devices can be made simple, owing to the good torque properties of the turbine,
- the gas generator/turbine gear combination with its auxilia¬ ry devices can be made lighter in weight than the correspond¬ ing combination in a piston engine, in which case the auto¬ mobile structure can even otherwise be made more lightweight,
- the need for maintenance is small, s_nce the number of wear¬ ing parts is small,
- the costs of manufacture are low owing to the simple struc¬ ture and the small number of parts to be machined,
- the efficiency is higher than that of currently used gas turbine engines of corresponding power, owing to the periodic combustion under high pressure and to a smaller amount of ex¬ cess air,
- no expensive and maintenance-requiring regenerator or cor¬ responding equipment is needed in the apparatus,
- the efficiency is good even with a partial load.
The invention is described below with the help of an example, with reference to the accompanying drawing, in which
Figure 1 depicts a longitudinal cross section of a gas genera¬ tor.
Figure 2 depicts a section through II-II in Figure 1, and
Figure 3 depicts a section through III-III in Figure 1.
The gas generator is made up of a cylinder frame 1 having plu¬ rality of vibration chambers 10 arranged in a circle and in conjunction with, i.e. inside, the vibration chambers a rotary valve block 2, by mediation of which the guiding of fresh mix¬ ture into the vibration chamber is arranged. On the outer cir¬ cumference of the valve block there are suction and exhaust slots 6, 7 opening into the vibration chambers in such a man¬ ner that the burned gas mixture is also controlled by the same valve block. The vibration chambers 10 are elongate, conically widening sectoral chambers. The suction and exhaust slots 6, 7 of the valve block 2 open into the narrower ends of the vibra¬ tion chambers. The valve block 2 is coupled by mediation of a rotor shaft 18 and a clutch 17 to a three-stage engine 4, by means of which the valve block 2 can be revolved during start¬ ing, and which at the same time serves as a brake for the gas generator and thus also as an electric generator. The rotor shaft 18 is supported by a thrust bearing 20 and a free bear¬ ing 21. The exhaust slot 7 has the shape of a Laval nozzle and is coupled directly to the gas turbine 3. The center inside the circle formed by the vibration chambers 10 forms a conduit via which the inflowing fresh mixture is directed from the suction frame 5 to the valve block 2. The injection of the fuel is arranged via a fuel nozzle 24 in the valve block 2, at a point immediately after the suction slot 6. The ignition of the fuel is arranged by means of an igniter 25 in the valve block 2, at a point after the fuel injection. An arrow in Fig¬ ure 2 indicates how the valve block 2 revolves clockwise. Ref-
erence numeral 8 indicates the suction aperture of the vibra¬ tion chamber, there being suction in the chamber 16. Above there is respectively an exhaust aperture 9, exhaustion taking place in the chambf 15, as indicated by an arrow. Figure 2 further depicts fuel injection 11, fuel volatilization 12, fuel ignition 13, and combustion 14. From the ignition genera¬ tor 27 the conductor 23 of the igniter 25 is led via the cen¬ ter. The fuel pump 28 ic' lso led to the fuel nozzle 24 via the center. In conjunct l with the vibration chambers 10 there are mounted a temperature gauge 32, a pressure gauge 31, and a pulse gauge 30, all of which for their part are coupled to the velocity control 29 of the gas generator in such a man¬ ner that the velocity of the gas generator can be controlled on the basis of variations in the temperature and the pressure so that the valve block 2 will revolve in synchronization with the vibration of the gas. Fresh gas flows via the gas genera¬ tor suction frame 5 to the valve block 2 and further via the suction opening 8 into the vibration chamber 16. The vibrating gas forms nodes of gas pressure and velocity, in which case the gas mixture burned in a pressure node during high pressure maintains the vibration, and under its effect during low pres¬ sure there flows into the vibration chamber fresh gas which maintains continuous operation. The burned gas flows via the exhaust slot 7 in the valve block 2 into the turbine 3, from which the power of the gas generator is obtained.
The invention is not confined to the schematic example de¬ scribed above; it can vary within the claims given below. Thus the vibration chamber may be a tubular or sectoral part con¬ verging at both ends in such a manner that the vibration cham¬ ber as if comprises two parts and can thus be double-acting, in both longitudinal directions. The exhaust slot 7 may be constructed so that it opens into the vibration chamber 10 at the end opposite to the suction aperture 8, or at a point be¬ tween the ends.