US1075677A - Gas-turbine. - Google Patents

Description

N. B. WALES.

GAS TURBINE.

APPLICATION FILED AUG.'21, 1912.

Patented Oct. 14, 1913.

2 SHEETS-SHEET 1.

mine ses N. B. WALES.

GAS TURBINE.

APPLICATION FILED AUG. 21, 1912.

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F a i M 6 J 2 4 p y N w WW. wy W d W i) am; sra'rns PATENT ihhhi-tle NATHANIEL B. WALES, .015 'EBOSTON, MASSACHUSETTS.

Gas-TURBINE.

"construction which can be operated efiiciently under variableloads and to this end I provide a plurality of independent, self- ,actuated impulse generators each of which can be worked at various speeds irrespective of the turbine shaft speed and can be cut-- out or thrown in as the casemay be, to govcm the power of the turbineandto adapt it to its load.

Another object ofitl e inyent on is, to provide generators which are self-actuated independently of each otherand to this end I provide means whereby each generator compresses its own working fluid to the; desired extent and in sufiicient quantity as required by it without reference to any other generatorr Another object of the inyention is to provide a generator adapted to generate high power in proportion to its weight and to this end I provide ,a generator, having a combustion chamber of relatively largeclearance volume.

.Other objects of the invention w ll he more specifically set forth and described hereinafter. D Briefly my gas turbine comprises a tur bine Wheel suitably connected to and operated by a plurality of independent, self-actuated impulse generators arranged in a,

circular plan. Each generator comprises a a suitable supply of air or gas and .a piston therein which piston is operated by the pressurc'generated in the combustion chamber after each explosion. In order to accomplish this result without aiiecting the efii- Specification of Letters Patent.

epplicatianfiled Augus 2 1 .12- al No 7 ,199-

Patented Got. 114, 1913.

ciency of the goneratorto any material extent I proyidea piston within said combustionchamber which connected to or inteseal with the piston in the compression ha the mer. p s on i g of relatively small area and just suiticient to operate the compression piston'in the compression chamber and to overcome frictionof the mechanism. e

In the accompanying drawings showing the best mode of carrying out my invention now knownto me, Figure 1 is a side eleva tion of ,a gas turbine constructed. and operated inaccordance with my invention and combined with an electrical generator; Fig. 2 is a vertical sectional View on line 2-2 in Fig. 1 showing the construction of a generator adapted torusing a fluid fuel in combination with air under compression and Fig. 3' is a vertical sectional view of a generator adapted for gaseous fuel.

Referring to the drawings illustrating the preferred embodiment of my invention Fig. 1 shows a gas turbine directlyconnected to electrica generator slot any well know n t u tion; \5 de ign ti g the turbine casg and 6- .thejenhaust ondui t ere .fllheturbine may be actuated by any number of generators butas shown in Fig. 1 it i YQ by. e ght indepen en selfeactuated impulse generato s a rang in .a ir r p an. m

1 Fig. .2, 7, designates a turbine wheel provided with suitable'buekets 8 and mounted on a shaft 9 supported in a suitable thrust bearing 10.

The meter-red form of generator shown in the drawings comprises a combustion chamber 11, a piston 12 having access thereto, a compression chamber 13 and a piston 14 therein. The pistons 12 and 14 may be 3 made integral as shown or may be independent- ,and connected so as to move in unison, order that the explosive pressure in the combustion chamber will directly operate the compression piston 14 The combustion chamber ll'is preferably constructed with a clearance yolunie in excess of the volume swept by the piston 12 and the area of the latter is so proportioned that its resultant power is just sufiicien'tto operate the compression piston ,to compress the working fluid to its required pressure and to overcome the friction of the operative parts.

The compression chamber is provided with suitable intake valves 15 through which is drawn the fluid to be compressed and with suitable exhaust valves 16 through which the compressed fluid is exhausted into a reservoir 17 through a pipe 18. As shown in the drawings, the compression chamber has two valves of each kind so as to compress both on the upward and on the downward stroke of the piston. In some cases it may be found preferable to compress the working fluid'on the upward stroke only of the piston in which case but one intake valve and one exhaust valve will be required. Any suitable valve of the automatic type may be employed for these purposes. From the reservoir the working fluid under compression is admitted to the combustion chamber 11 through a valve 19 at the proper time. At this point there is a slight difference in construction between the generator shown in Fig. 2 and that illustrated in Fig. 3. The latter is designed to use a gaseous combustible fluid and the former to use liquid fluid in connection with compressed air and therefore in Fig. 3thevalve 19 admits to the combustion chamber the gaseous fluid under compression and ready for ignition but in Fig. 2 the valve 19 admits air under compression. In the latter case the liquid fuel is sprayed into the combustion chamber at the proper time through a valve 20 to produce the explosive fluid. Any suitable ignition means may be arranged within the combustion chamber as for instance a spark plug 21. Such portions of the combustion chamber as may be necessary may be sur rounded by suitable water jackets 22.

In the construction shown in Fig. 2 where compressed air is used the reservoir 17 is preferably so made as to surround the combustion chamber and the turbine exhaust 6. This arrangement has a double advantage in that the reservoir serves as a cooling jacket for the combustion chamber and other heated parts and the heat absorbed by the compressed air raises its temperature and increases the efficiency of thegenerator.

The combustion chamber 11 is provided with an exhaust opening 23 communicating with an exhaust chamber 24 from which the gases flow through an exhaust valve 25 and opening 26 to the buckets 8 of the turbine wheel. The exhaust valve is made up of two disks 27 normally seated in two openings in the valve casing 28 so that the valve is at all. times balanced. The valve is of such dimensions as to permit of a free flow of the gases to the turbine when the valve is open.

Any suitable means may be provided for operating the exhaust valve at the proper times and one such means is shown in .the drawings in which the piston 14 is connected by a piston-rod 29 and a crank-arm 30 to a fly-wheel 31. 'Upon the shaft of the flywheel is a beveled gear 32 meshing with a similar gear 33 mounted on a shaft supported in a bracket 34; the other end of the shaft carrying a beveled gear 35 meshing with a beveled gear 36'mounted on a vertical shaft 37 supported in a bracket 38 and thrust bearing 39! The shaft 37 carries an eccentric cam 40 which operates the exhaust valve 25 through the medium of a valve stem 41. A spring 42 maintains the valve in a normally closed position except when it is held open by the cam. The gears 35 and 36 are so proportioned that the cam operates the exhaust valve at the proper time in the operation of the generator. To operate the valve 19 admitting compressed gaseous fluid into the combustion chamber or the valve 20 admitting liquid fuel, a cam 43 is mounted on the shaft 37, which cam operates the valve through the medium of a valve stem 44, a spring 45 serving to maintain the valve in a normally closed position.

The valves of my generator are so de-. signed that the generator is in short an enlarged clearance volume four cycle gas engine, the clearance volume being represented by the combustion chamber 11 in which a large volume of gas under pressure is ignited resulting in a large volume of high pressure gas which is exhausted through the valve 25 onto the blades of the turbine 7.

The operation of my gas turbine is as follows: Taking the condition as shown in Fig. 2, the combustion chamber 11 is filled with an explosive mixture made up of compressed air which has been admitted through the valve 19 and liquid fuel which has been sprayed through the valve 20. As soon as the piston 12 has passed its lower dead center, a spark is generated by any suitable mechanism in the spark plug 21 thereby igniting the explosive mixture in the combustion chamber and forcing back the piston 12 in the usual manner as in a four cycle gas engine. Just before the piston 12 reaches its extreme upperposit-ion exhaust valve 25 is opened by its cam 40 and the gas under pressure issues through the valve to the bladesof the turbine. The pressure in the combustion chamber is not materially reduced by the upward movement of the piston since the clearance volume of the combustion chamber is. much larger than the volume swept by the piston, and therefore approximately the full force of the explosive pressure is expended upon the turbine. The exhaust valve remains open for a period and when the pressure' in the combustion chamber has fallen below the pressure in the reservoir 17, the valve 19, which is automatic, opens and allows the compressed air to flow into the combustion chamber and out through the exhaust thereby scavaging the chamber, and forcing out the products of combustion. The operation of the exhaust imam? is so timed that it is held 0 en a sutiicient period to permit of this result. In addition to scavaging the combustion chamber, the eompressedair also cools the chamber, the exhaust valve and turbine blades thereby preventing excessive temperatures in those parts. During this time the piston 12 has returned to the position shown in Fig. 2. The exhaust valve is then closed and the automaticvalve 19 remains open until the pressure in the combustion chamber equals that in the reservoir 17 during which time the piston has again receded. On its return it' compresses the contents of the combustion chamber to a slight degree and liquid fuel is sprayed into the chamber and when the piston passes its dead center the mixture is exploded.

In Fig. 3 I show a slight modification of Fig. 2 in so far as the impulse generator is concerned, as follows: The intake valves 15 of the compressor 13 are connected to a source of suitable gas, such as for instance a suction-type gas producer. The gas enters through valves 15, is compressed in compressor 13 and passes through exhaust valves 16 into the reservoir 17, which is con nected to a suitable intake valve 19 which corresponds in all respects to the intake valve of a four cycle gas engine. In this form I show the combustion chamber 11 surrounded by a water jacket 22, in that I have no scavaging and cooling features as shown in Fig. 2, therefore I prefer to surround the combustion chamber as well as the exhaust valve, with a suitable water jacket. The exhaust valve 25 is similar to the exhaust valve in a four cycle gas engine and the mode of operation of the impulse generator, as shown in Fig. 3 carries out the exact requirem'entsof operation of a four cycle gas engine. The intake valve may be variably governed, or the impulse generator may be speeded up or slowed down by a suitable throttle as in a conventional four cycle gas engine, or it may be varied in speed by advancing or retarding the spark in the spark plug 21 so that the rate of impulses delivered to the turbine may be varied as desired. I have found that it is best to run the impulse generator shown in Fig. 3 on a lower number of impulses per unit number than in Fig. 2 so that the average temperature of the exhaust gas will not exceed a workable temperature in respect to the turbine. This type of gas turbine is particularly adapted to large power units such as those in power stations for running a dy-- name and with a plurality of independent impulse generators, one can always be kept in reserve so that if any accident happens to one of these in ordinary use, it can be immediately stopped and the reserve one cut in without affecting the power developed in the turbine excepting during the time of change. Also this form of gas turbine is especially desirable in that it can be so designed that for the average load there will be three or four generators idle and as peaks come on during the rush hours of the day, reserve units can be thrown into operation thereby adapting itself to an over-load over the normal output of the unit. This is particularly desirable in power station work and overcomes one of the great drawbacks in the ordinary gas engine which lacks flexibility and overload capacity.

Temperatures delivered by this apparatus compare in all respects to exhaust temperatures in the ordinary four cycle gas engine so that steel construction can be used without regard to abnormal temperatures.

It is to be noted that one of the important features of my invention is that I am enabled to transform into kinetic energy which is utilized to compress the succeeding charge of working fluid a small amount of the upper range of pressure generated in the combustion chamber at the moment of explosion thereby not materially reducing the pressure of the gases in the combustion chamber which are available for expansion on the turbine blades, together with the fact that, through the intermittency of the cycle employed in the generator, my temperatures are no higher or more severe on the turbine structure than those in the ordinary four cycle gas engine.

My invention may be embodied in con structions other than that herein shown and described and I desire to claim it broadly except where it is specifically limited in the following claims.

I claim 1. A gas turbine comprising a turbine and a plurality of impulse generators each of which is independently actuated by its explosion pressure.

2. A gas turbine comprising a turbine and a plurality of independent, self-actuated impulse generators.

3. A gas turbine comprising a turbine and a plurality of independent impulse generators in operative connection therewith; each of said generators comprising a combustion chamber and means for compressing the fluid supplied to said combustion chamber, said compressing means being operated by the pressure generated in said combustion chamber after each explosion.

1. A gas turbine comprising a turbine and a plurality of independent, self-actuated impulse generators; each of said generators comprising a combustion chamber and means for delivering to said chamber fluid under pressure.

5. A gas turbine comprising a turbine in combination with a plurality of independent, self-actuated impulse generators; each -pawuma of said generators comprising means for generatingintermittent impulses by the explosion of a fluid under pressure.

6. A gas turbine comprising a turbine in combination with a plurality of independent, self-actuated impulse generators; each of said generators comprising means for generating intermittent impulses by the explosion of a fluid under pressure and means operated by said impulses for compressingsaid fluid before it is exploded.

7. A gas turbine comprising a turbine in combination with a plurality of independent impulse generators; eachof said generators comprising a combustion chamber, a piston having access thereto and means actuated by said piston for compressing the working fluid before it is supplied to said combustion chamber.

8. A gas turbine comprising a turbine in combination with a plurality of independent, self-acting impulse generators; each of said generators comprising a combustion chamber, a compression chamber, a piston having access to said combustion chamber and provided with means for compressing the working fluid in said compression cha nmvam ing a greater volume than the volume of that portion swept by the said piston.

11. A gas turbine comprising a turbine in combination with a pluralityof independent, self-actuated impulse generators; each of said generators comprislng a combustion chamber, havlng a clearance volume in excess of the volume swept by the piston, a piston having access to said chamber and means actuated by said piston for compressing the working fluid before it is supplied to said chamber. 7

12. A gas turbine comprising a turbine wheel and a plurality of independent, selfactuated impulse generators, each of said generators having no mechanical connection with the turbine wheel and each compris- 6o -ing a combustion chamber with a piston' having access thereto, said piston being actuated by the explosion pressure in said combustion chamber before said explosion pressure is given access to the turbine wheel,

and means for delivering to said chamber a working fluid under pressure.

13.'A gas turbine comprising a turbine wheel and a plurality of independent selfactuated impulse generators, each of said generators having no mechanical connection with the turbine wheel and each comprising a combustion chamber, a piston having access thereto, and means whereby the pressure generated in said chamber after each explosion is utilized for compressing the next charge of working fluid before the pressure is given access to the turbine wheel.

In testimony whereof, I hereunto set my hand in the presence of two subscribing witnesses, this the twentieth day of August,

NATHANIEL B. WALES.

Witnesses:

E. F. Nome, F. J. V. DAKIN.

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