US1278499A - Internal-combustion turbine. - Google Patents

Description

R. ESNAULT-PELTERIE.

INTERNAL COMBUSTION TURBINE.

APPLICATION FILED JULY 8. 1915. RENEWED FEB. 1.1918.

1,278,499 Patented Spt. 10, 1918.

2 SHEETSSHEET 1- R. ESNAULT-PELTERIE.

INTERNAL COMBUSTION TURBINE.

APPLlCATlON FILED JULY 8. 1915. RENEWED FEB. 1,1918.

Patented Sept. 1() 1918.

2 SHEETS-SHEET 2.

"* IQE.

' ROBERT ESNAULT-PELTERIE, 0F BOULOGNE-SUR-SEINE, FRANCE.

INTERNAL-COMBUSTION TURBINE.

Application filed July 8, 1915, Serial No. 38,640.

and useful Improvements in Internal-Combustion Turbine-Engines, of which the following is a specification.

The principal obstacle that an engineer meets with in producing an internal combustion turbine engine is the difficulty of limiting the temperature of the gases which act on the vanes ofthe motor disk.

Thelimiting of this temperature is so important that several treatises and patents have been devoted 'to the investigation of the most practical manner of overcoming the difliculty. It is this limitation which until now has stood in the way of a practical solution of a combustion turbine.

Different methods have been conceived of obviating it and. they can be classed under two categories 1. Cooling by means of theexpansion of the combustion gases.

2. Limiting the temperature of the said gases by the means of water or steam.

The first solution gives rise to a considerable expansion of the gases at a rapid rate. The hydraulic efficiency of the turbine is then so lovs that it. is impracticable; the

work done by the wheel being less than the work expended on the compression.

The second solution leads to the loss, in the condenser, of the heat of vaporization of the Water employed, and this loss is prejudicial to the efliciency of the engine. It can be reducedby various artifices which need not be examined here, but even with the help of these artifices, this second solution allows of a satisfactory efiiciency being attained only by the employment of very high pressures, 30 kilograms for instance.

The present invention has for its object a combustion turbine system Whose end is to overcome these several dilliculties and allow of the production of a motor with" a very good output and consequently small consumption without recourse to very high pressures.

The cycle followed in this machine is,

however, of known character and is as follows I 1. Compression of the gas. It is advantageous that this compression should be as nearly isothermic as possible, but it can, in

Specification of Letters Patent.

Patented Sept. 10, 1918.

Renewed February 1, 1918. Serial No. 214,986.

certain cases referred to later on, be perfectly adiabatic without affecting in an appreciable manner the total output.

2. Heating the compressed gases, by the exhaust gases in a heat exchanger.

3. Combustion efi'ected under special conditions which are hereafter defined and constitute one of the important features of the present invention.

4. Adiabatic expansion with loss of heat and production of useful energy.

All authors, who have studied the question and have published works thereon, have always arrived at this conclusion that the output was the better the higher the ratio of the pressure used.

The applicant, in studying the question has perceived that this assertion is only partially exactand that the above cycle, followed without careful consideration, in nowise by itself insures good outputs being obtained, even with high pressures. On the contrary, it is only under certain conditions that the said cycle can yield really good results, especially with low pressures.

The present invention has especially for its object the different conditions that should be observed in constructing the engine referred to to obtain such results. The conditions are as follows First of all, the fall of pressure being.

small there is during expansion a trifling reduction of temperature, and the gases, be- I foreexpansion, should have only a relatively low temperature.

It is then evidently necessary that the quantity of combustible introduced into the air should be suitably limited and in every case much smaller than the maximum quantity necessary for complete carburation.

If the air be carbureted in an incomplete manner, the result would be that the components of the combustible mixture would be in proportions far from what is best and the combustion would be too slow and could mitted to the nozzles, expands and acts on the blades of the turbine. The heated gases which issue from the turbine are then led 'into a heat or temperature exchanger, where than that of combined converging and diverging nozzles especially when these latter are of moderate len h.

In this case, however, the fall of temperature during expansion is, as stated above, relatively small and the loss of temperature in the heat exchanger can be-nearly proportional to the said fall in temperature. There naturally results an appreciable lowering,

in the output.

To obviate this difliculty, it is better to make use of several stages of expansion, taking care to pass the gases into a combustion chamber between each stage of expansion, so as each time to raise their temperature by the quantity they have been lowered during the preceding expanslon.

This arrangement is qulte posslble, because, as stated above, the air each time receives only a quantity of combustible much less than what is necessary for complete combustion, and consequently, after these partial combustions, there still remains for the succeeding combustions a sufiicient quantity of oxygen.

The present process, moreover, possesses the advanta e that the mass of as per horse power whic traverses the tur ine, can be considerably reduced and the number of calories transmitted by the temperature exchanger be also equally reduced. Moreover, the loss of temperature in the said exchanger is inversely proportional to the number of expansion stages. c

In the case where there are many expansion stages it is possible, without inconvenience, to utilize, as mentioned above, adiabatic compression, but it is nevertheless desirable that this compression be effected in several stages (for preference in number at least equal to the number of sta es of expansion), care being taken to cool the gases effectively between each stage.

From the point of view of the losses of temperature the combustion chamber about to be described is particularly favorable, for it is disposed in such a way that the gases which arrive from the. compressor at the said chamber commence to pass around it many times in a manner to recover or take .the gases which emanate from the temperature exchanger be circulated once or twice. To the same end, it may 'beremarked, a farther preferred arrangement may be employed. Instead of placing the lagging around the chamber, this arrangement consists in putting the chamber within thetemperature excha er by disposing the latter around the cham er in a manner to preserve the general arrangement in which the temperature of "the gases constantly increases from the exterior toward the interior.

In the accompanying drawing, Figure 1 is a view in longitudinal section of-thecombustion chamber embodying the .conditions enumerated above.

Fig. '2 is a sectional-view of the combustion chamber with its jacket for recovery of lost heat.

Fig. 3 is'a view, partially in elevation and partially in vertical section, illustrating a three stage gas turbine, the section being along the line a: y zu a) 10, F 4.

Fig. 4 is the. top plan view of the gas turbine illustrated in Fig. 3.

In Fi 1 and 2 is an annular space a, in which an arrives .under pressure. This air, following the course indicated by the arrows in Fig. 1, is divided into two portions proportional to the two sections 6 0 presented to them. The portion which traverses section '0 is generally thesmaller, and is that which should be carbureted and burnt. For

this purpose, a nozzle 11 enters the cavity a and pulverizes the combustible for example by opposing the gaseous current. A sparking plug e placed just opposite the carbureted current allows firing at. the start off subsequent to which the combustion can maintain itself, it being understood of course that the sections 2 are madeso large that the speed of the gas may be less than that of the speed of the propagation of the flame in the mixture.

The two portions of air, always following the direction indicated bv the arrows, meet in the end f of the chamber and mixing return by the annular space 9. They proceed .toward the other end and are admitted into the nozzles h h from which they escape to act on wheel 2' 'of'the turbine, which wheel Y can be conveniently mounted as a false door as the figure shows. Y

The combustion chamber can be disposed in a manner to give free passage to the turpossible to place the bearings farther from bine shaft which can be supported between two bearings. In this arrangement it will be the heated disk'of the turbine, so that they will not seize. Such constructions can be carried out in many suitable ways, which need not be here indicated. I

Of the three spaces a, g, b, it is the central space 0 which contains gases at the highest temperature and it is the outer space 6 which contains the cool gases or at least the nearly cool gas arriving from the compressor. In this way, the heat lost by the gas in a through the wall 7' is taken up by the gas which traverses the space 9 and is given up to the turbine. The heat lost by the gas in the inclosure'g across the Wall is is taken up by the gas admitted to the inclosure b and only the heat lost by the latter through the wall Z is really lost without recovery. However, it is naturally allowable and advantageous that the wall Z be surrounded by a covering as heat-retaining as possible,

which is easily done owing to the low temperature of the gas, a low temperature which contributes besides to limit the total loss.

On Fig. 2 is shown in section the temperature exchanger disposed around the combustion chamber. The space m communicates with the space a, previously referred to, by a large orifice n. The chamber m terminates at its other extremity by a partition 0 in which are fixed the ends of tubes 19. These tubes are rolled around the combustion chamber with a metal sheet 9 which describes with them a spiral whose convolution forms a helicoidal space for the tubes. The tubes are kept in place by suitable p'erforated plates 1', 1', which have holes for the tubes 32 and supplementary holes for the circulation of gas around the tubes. At their outer ends the tubes 1) open into the chamber t which through orifice u receives gases forced in by a fan. The space exterior to the tubes has near its inner end an orifice c which is connected to the exhaust of the turbine. At its exterior end the same space can communicate with the atmosphere or with an appropriate. exhaust pipe through orifice s.

It is evident that under these conditions the temperature exchanger is traversed exteriorly to the tubes by a centrifugal current of exhaust gas and internally of the tubes by a centripetal current of air from the compressor. The two gaseous currents exchange their temperatures across the walls of the tube in such a way that the same principle is always observed, namely that the temperatures always increase from the exterior toward the interior and in a way that the heat lost in any one portion is recovered in the part of the apparatus which surround it and moreover the heat preserving envelop which it is advantageous to use on the outside only acquires a small-tempera- Air is partially carbureted in the combustion chamber 9 by fuel asolene for example) coming from the supp y pipe d. Being thus additionally heated, the air expands against the first wheel i, there loses heat in consequence of the expansion, is then reheated by a. second combustion of fuel therein in the second combustion chamber 9 parallel to g. The air again expands, and again loses heat 1n passing through the second wheel '5 The air (or rather the air containing the products of combustion) is again reheated by a third combustion of fuel therein in the third chamber g' and expands against the third wheel 6 and the air and combustion products mixture finally gives up its calories 1n the temperature exchanger 4, before passing out in the atmosphere at 6.

The combustion, therefore, in the example just referred to, takes place at three times or stages, the oil fuel being injected through pipes d, (1 d in such a manner that each of the wheels 5, z, i is under identical condit1ons of temperature. 1

These successive combustions are advantageous, because they permit of having the maximum suitable temperature at all of the turbine wheels 71, i i and there is the capabillty of a large excess of air being used, as regards the fuel injected.

Claims:

l. A process of converting fuel energy into mechanical work, comprising combusting a combustible fuel and combustion-supporting gas 1n an inclosed space under pressure, mixing the gas formed with other gas at a lower temperature, directing a jet of the compressed and partially cooled gas against the rotor of the turbine, the gas being allowed but a small degree of. expansion in passing through the turbine, consequently undergoing but a slight loss in temperature, combusting a further quantity of fuel in the partially cooled gas to restore the loss in temperature, and again allowing the gas to expand slightly to perform work, and repeating the combusting of further quantities of fuel and slight expansion of the gas.

2. A process of converting fuel energy into mechanical work comprising combusting a combustible fuel and a combustion supporting gas, the resulting gas containing suflicient quantities of combustion supportrooting a jet of compressed gas a ainst the rotor of a turbine, the gas being allowed but a small degree of expansion in passing' through the turbine, consequently undergoing but a slight loss in temperature, combusting a further quantity of fuel in the par-' tially cooled gas to restore the loss in temperature, and again allowing gas to expand slightly to perform work, and repeatin the combustion of further quantities of fuei and slight expansion of the gas.

3. An apparatus of the character described comprising a generator havinv a hollow interior, a parti. lly inclosed combustion chamberin said generator, means for introducing a liquid-fuel into said combustion chamber,

means for introducing a'combustion supporting gas into said combustion chamber and to the interior of said generator, said combustion chamber being in communication with the interior of said generator, whereby the gases of combustion may passinto and mix with the gas in the interior of said generator, and a heat regenerator around said generator, said regenerator comprising. a spiral conduit through which exhaust gases pass in an evolute direction and a spiral conduit in heat interchanging relation with the other conduit through which gases entering the generator pass in an involute direction.

In witness whereof, I have hereunto signed my name in the presence of two subscri ing witnessse.

ROBERT ESNAULT-PELTERIE. Witnesses:

DANIEL C. POOLE, Jr., GABRIEL BELLIARD.

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