US2544941A - Gas turbine plant - Google Patents

Description

March 23:, 1951 R STRUB 2,544,941

GAS TURBINE PLANT Filed May 2, 1944 I g 7 g l x h- 4 39 I13 INVENTOR: RENE STRUB ATTO EY Patented Mar. 13, 1951 UNITED STATES PATENT OFFICE GAS TURBINE PLANT Ren Strub, La Chaux-de-Fonds, Switzerland, assignor to Sulzer Freres, Societe Anonyme, Winterthur, Switzerland Application May 2, 1944, Serial No. 533,676

bine to the turbo-compressor a heat-exchanger may be provided through which heat is supplied to the expanded fresh air. It is expedient for the waste heat from the plant, for instance that contained in the heated cooling-water, to be supplied to this heat-exchanger. It is preferable to regulate the passage of heating medium through the heat-exchanger in accordance with the air temperature at the entrance to the turbocompressor in such a way that the air temperature is adjusted to aconstant level. The passage of heating medium can be interrupted as soon as the air temperature at the entrance to the turbo-compressor exceeds a certain fixed figure. The passage of cooling-medium through the cooler can be so regulated that the temperature of the cooling-medium remains at an approximately constant level.

One exemplification of the invention is explained in more detail below with the aid of the drawing.

The working-medium compressed by the lowpressure compressor I passes through the intermediate cooler 2 into the high-pressure cornpressor 3 and then, after having been brought up to the maximum working pressure, is preheated in the tubes of the heat-exchanger 4. At the point 20 in the outlet pipe from the heatexchanger the working medium is divided. A part of it passes through pipe 2| into the heater 5' where it fiows over the heat-exchange tubes and is brought up to the maximum working temperature.

The compressed and heated working medium then passes into the turbine 6, expands there and flows into the space surrounding the tubes of the heat-exchanger 4, where it gives up part of its residual heat to the working medium coming from the compressor 3. A further part of the residual heat is led off by a coolingmedium in the cooler 1, whereupon the working medium again flows to the low-pressure compressor l and recommences the circuit.

burner of the gas heater 5 as combustion air.

The combustion gases flow through the heatexchange tubes and then pass to the turbine 8 from which they can be led 01f after expansion to further points of consumption not shown in the drawing, for instance to heat-exchangers, or to atmosphere.

,The turbo-compressor I l continually supplies air from the atmosphere to the open circuit in the plant to replace the quantity withdrawn. This make-up quantity is introduced into the heat-exchanger 4 at a point at which the working medium flowing back from the turbine 6 is at approximately the same temperature as the make-up quantity.

The turbine 6 operated by the flow of work- 7 ing medium in the circuit drives the compressors The other part of the working medium after I, 3 and H, while the turbine 8 operated by the quantity withdrawn produces the useful output given up to the outside. This useful output turbine, for instance, drives the ship's propeller 24 through the useful output shaft 25 and the gear 23. The useful output is adjusted to be greater or less by the raising or lowering of the sequence of pressures of the working medium flowing in the circuit.

A turbine 9 with an adjustable distributor I0 is provided before the turbo-compressor I l which continuously supplies the fresh air. The output of this turbine is transmitted to the useful output shaft 25. The air from atmosphere passes through the distributor II] to the blades of the turbine rotor. Each blade of the distributor I0 is mounted on a shaft placed at right angles to its profile. All the blades can be adjusted in common about the shaft, so that the crosssection of flow through the distributor is increased or reduced and at the same time the inflow angle of the air is made steeper or flatter. After expansion in the turbine to a pressure below atmospheric the air passes through the pipe 26 to the turbo-compressor II.

The air is compressed by the turbo-compressor H to a higher or a lower pressure according to the degree of expansion in the auxiliary turbine. In this way the sequence of pressures in the working medium circuit is also adjusted to be higher or lower and the useful output is thus increased or diminished. If the distributor I!) is adjusted for a larger cross-section and a steeper inflow angle, then a higher sequence of pressures results and consequently a greater output is obtained from the plant than when the distributor is adjusted for a smaller cross-section offlow and a flatter inflow angle.

In the pipe 26 a heat-exchanger I2 is arranged through which heat is supplied to the fresh air expanded in the auxiliary turbine. The coolingmedium heated in the cooler I flows through the tubes of the heat-exchanger I2 and gives off part of its heat to the expanded air. In this way the danger of ice formation in the compressor l l, is obviated. The fresh air can be supplied to the compressor at a temperature at which the moisture in the air is no longer precipitated in the form of needles of ice on the walls of the. .the adjustable blading IQ of the turbine 9 is pipes and the compressor blades.

In the supply pipe 2? of the heat-exchanger 12 a regulating member M is provided. Further, a by-pass pipe 28 with a regulating member lv is connected to the pipe 21. Both regulating members l4 and I5 are controlled by a. thermostat [3, which in its turn is inffuenced by the" fresh air heated in the heat-exchanger IE2. B'yfi] means of this regulating device the temperature of: the fresh air is maintained at such a level:

that no ice formation can take place and further no undesirable increase in the work of compres sion in compressor H arises. 1 V When the output of the whole plant is high,v only a slight expansion of. the air in the turbine 9, if any, takes place, so that the air temperature remains above freezing point when the temperature of the surrounding air is normal. In this case the heating of the; heat-exchanger would only be harmful to the running of the whole plant because of the increase in the work done by the compressor. The passage of water through the heat-exchanger i2 is then completely interrupted. is closed while the regulating member W in the by-pass pipe is' open.

When the output decreases, increased expansion of the fresh air is caused by the adjustment of the distributor if] of the turbine 9. As expansion increases, the cooling of the fresh. air is intensified. If the air temperature approaches freezing point, the regulating member M is opened by the thermostat i3 and the heating medium is freed to flow through the tubes of the heat-exchanger l2. The control by the thermostat l3 can be so adjusted that, for instance, the supply of heat-isinterrupted at air temperatures above 4 C.,

while at temperatures below 4 C. heating medium is supplied in such quantities that the air ESE l perature only falls very slightly below 4 C. In, this way the temperature can be maintained-in the neighbourhood of 4* 0. approximately.

In the cooling-medium supply pipe '29 ofthe; cooler l a regulating member is is provided which is influenced by the thermostat ea in the pipe 21. The influencing of the regulating member Hi is effected in such a way that the outlet temperature of the cooling-medium from the cooler remainsapproximat-ely constant. When the load on the plant is slight, this regulating member is nearer to its closed position in accordance with the decreased heat abstraction. in the cooler 1', while when the load is greater, the member. is nearer to its open position. The end is thus attained. that, when the load on the plant is. slight, the difierence of temperature between the heating medium and the air to be heated in the heat-exchanger i2 is sufficient to enable the. quantity of heat particularly required to be supplied to the air.

To the pipe 22. leading from the turbine 9 to the turbo-compressor H is connected a supply pipe 3| with a closing member -1, through which,

The regulating member; hi

25 compressor,.an air heater disposed 4 when the load on the plant is great, air can be introduced from atmosphere direct into the pipe 25, the turbine 9 being by-passed. In this way any throttling of the air supplied to the turbocompressor H is avoided.

The invention offers the advantage that the balance of power provided and consumed by the turbo-set I, 3, 6, H can. he maintained independently of the load on the whole plant. The extra output which arises from the regulation without loss of the turbo-compressor H by means of transmitted direct to the useful output shaft 25.

The transmission of the output of the turbine 9 to the useful output shaft may in principle be effected equally well by electric, magnetic, hydraulic or similar means. The heating of the 'heat-exchanger'l2 may also be done by means ofexhaust gases from the plant or the coolingmedium of another cooler, for instance the intermediate cooler 2. The heat might .alsobe transmitted direct from the coolers to the heat exchanger l2 without the use of a heatecarrying' medium. The heated working medium would then flow directly through the heat-exch'an'ger.' Iclaim: 1. A gas turbine, plant comprising, in combinai tion, an auxiliary operating circuit includin an auxiliary turbine, a main compressor driven. by said turbine and receiving operating gas 8X7. hausted therefrom for compression, a gas heater for heating the gas compressed in said com-1 prssor and supplying heated and compressedgas to-said turbine for operating same, andi an aux-Q iliary air compressorconnected to and driven by said turbine and having air intake means, and supplying compressed air to said auxiliary cir'e, cult ahead or said heater; a power shaft, amain gas turbine receiving operating gas from said heater and connected to and driving said power shaft, and an atmospheric air pressure operated turbine connected for air how to and exhausting into said air intake means and connected toand supplying power to said main shaft and having adjustable air intake means for controlling the flow of air from the atmosphere to said auxiliary. circuit and the power output of said plant. 'ff

2. A gas turbine plant as defined in claim 1, comprising an air heater disposed in said air in,- take means and heating the expanded air drawn from said air-operated turbine before it enters the auxiliary air compressor.

3. A gas turbine plant as defined in clai'mll', comprising conduit means for conducting th jex haust from said auxiliary turbine to said compressor, an air heater disposed in. said ai'r intake means for heating the expanded air drawn from said atmospheric. air pressure turbine; beg fore it enters the auxiliary air compressor, and heat transfer means connected with said conduit means and with said air heater for transferring heat from the exhaust of the auxiliary turbine to the air exhausted from the atmospheric airpres sure turbine. 4. A: gas turbine plant as defined in claim 3', said heat transfer means comprising a conduit having a heat receiving portion disposed in said conduit means. and a heat dispensing portion. dis posedin said air heater and a heat carrying fluid circulating from the first portion to the second portion of said conduit. 7

5. A gas turbine plant as defined in claim' l comprising conduit means for conducting the-exhaust from said auxiliary turbine to said main intake means for heating the expanded air drawn from said atmospheric air pressure turbine before it enters the auxiliary air compressor, a conduit for a heat carrying fluid, having a heat receiving portion disposed in said conduit means and a heat dispensing portion disposed in said air heater for transferring heat by said fluid from the exhaust of the auxiliary turbine to the air exhausted from the atmospheric air pressure turbine, and temperature responsive control means connected with said conduit and controlling the flow of heat carrying fluid therethrough.

6. A gas turbine plant as defined in claim 1, comprising conduit means for conducting the exhaust from said auxiliary turbine to said main compressor, an air heater disposed in said air intake means for heating the expanded air drawn from said atmospheric air pressure turbine before it enters the auxiliary air compressor, a conduit for a heat carrying fluid, having ,a heat receiving portion disposed in said conduit means and a heat dispensing portion disposed in said air heater for transferring heat by said fluid from the exhaust of the auxiliary turbine to the air exhausted from the atmospheric air pressure turbine, temperature responsive means connected with said air intake means between said air heater and said auxiliary air compressor, and control means connected with said temperature responsive means and with said conduit and controlling the flow of heat carrying fluid through the portion thereof disposed in said air heater in dependence on the temperature of the air entering the auxiliary compressor.

7. In a gas turbine plant, the combination of a turbo-compressor supplying the compressed air needed by said plant and having air intake means, a main power shaft, a main turbine connected with and operating said shaft, an atmospheric air pressure operated turbine disposed for air flow in said air intake means and being connected with and contributing power to said shaft, adjustable air intake guide vanes connected with said air operated turbine and controlling the flow of air from the atmosphere to and the power output of said plant, a heat exchanger connected to and receiving heat from gas exhausted by the turbine of said turbo-compressor and transferring it to a heat carrier medium, flow control means connected with said heat exchanger and controlling the flow of said medium therethrough and being responsive to the temperature of said medium as it leaves said heat exchanger, and an air heater receiving heat from said medium and being disposed in said air intake means and heating the expanded air drawn from said airoperated turbine before it enters the compressor of said turbo-compressor.

RENE STRUB.

REFERENCES CITED The fo lowing references are of record in the file of this patent:

UNITED STATES PATENTS

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