DE1239890B - Combined gas-steam power plant - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

FOIk

German class: 46 h

Number: 1 239 890

File number: S 886011 a / 46 h

Filing date: December 6, 1963

Open date: May 3, 1967

The invention relates to combined gas-steam power plants, in which those heated by a nuclear reactor, for example Steam generator-fed steam turbine supplies the base load and the gas turbine supplies the peak load, whereby a series of feed water preheaters heated by means of bleed steam, at least in part in parallel are arranged by the gas turbine exhaust heated feedwater preheaters.

For various reasons it is necessary in power plants to generate electrical energy od. The like. Provide the possibility of being able to generate energy peaks over and above the base load. This is particularly necessary in the case of steam turbines, the steam generators heated by nuclear reactors have, since such systems are always operated under full load for economic reasons Need to become.

It is well known the power of a steam powered vehicle working power generation plant to increase that a continuously running gas turbine on the system is connected. In the case of heavy loads, the liquid returned from the condenser becomes liquid Propellant through bleed steam from the steam turbine in heat exchangers and partly also preheated by means of waste heat from the gas turbine. In this case, when the steam is applied to the turbine weakly for better utilization of the fuel, the caloric efficiency of the system is improved, that with low load the propellant is preheated only by gas turbine waste heat, while the taps of the steam turbine are opened when the load is higher.

In contrast, the object of the invention is to improve the performance of a preferably always piractic to improve running at full load steam turbine for peak loads so that the of A turbine, which is only designed for base load, is fed with additional propellant at peak times how steam can be supplied.

To solve this problem, in a combined gas-steam power plant, the method described at the outset is used Art proposed one of the exhaust-gas heated feedwater preheaters as an evaporator to train, its closable outlet via a relative to the regenerative preheater assigned to it The tapping line is closed and the steam generated and possibly superheated directly returns to the steam turbine. So it is used in addition to the steam turbine for peak times a gas turbine whose hot exhaust gases are used to generate steam and ge-combined Gas-steam power plant

^Applicant:;

Societe Rateau SA, Paris ... ', -. . ,. Representative: '' ■ · '■

Dr.-Ing. Dr. jur. F. Redies, Dr. rer. nat. B. Redies and Dr. rer. nat. D. Türk, patent attorneys, Opladen, Rennbaumstr. 27

Named as inventor:

Marcel Henri Louis Sedille, Paris.

Claimed priority:

France of December 10, 1962 (918 101) -

possibly to overheat that of the steam turbine in addition can be supplied to the steam supplied by the steam generator. The exhaust gases from the gas turbine are still warm enough even after overheating a portion of the propellant to preheat condensed feed water sufficiently so that the taps at peak times the steam turbine can remain closed.

The invention is particularly suitable for steam power plants in which the steam turbine with constant Actuation works and the temperature gradient practically due to the temperature in the steam generator is limited, which is the case, for example, with steam generators heated by nuclear reactors is. Here, the temperature and the steam pressure in the last stages of the steam turbine are proportionate low, so that an additional introduction of motive steam in, for example, the medium pressure stage a significant improvement in the efficiency and the total output power of the steam turbine proclaimed. So there is not only an additional steam turbine for generating at peak times electrical power available, but the maximum power output by the steam turbine can be significantly improved by making sensible use of the exhaust gases supplied by the gas turbine.

Combined gas-steam power plants are known in which the propellant of a steam turbine is heated in two different streams by means of the exhaust gases of a gas turbine. Here will be

709 578/79

3 4

different final temperatures of the blowing agent in a boiler C generated. That in a kondensa-

reached, so that the two partial flows at different gate K accruing water is in the boiler via a

which points are introduced into the steam turbine. Line, in which a pump P ₁ , a valve

have to. The exhaust gases from the steam turbine heat up to F ₀ , a number of feed water preheaters R ₁ ,

in each case the propellant of the steam turbine, 5 R ₂ , R ₉ ... R ₇ , in which the water with a suitable

ie not only during peak times. neten places of the turbine via the valves V ₁ , V ₂ ,

According to one embodiment of the invention, V is ₃ . . .V ₁ removed bleed steam heated

in a system of the type described, in which a valve F ₁₀ and a pump P ₂ are arranged

which is heated with the gas turbine waste heat. The feed water preheaters are in two groups

water preheater one behind the other in the exhaust gas stream io pen divided, the preheaters R ₁ , R ₂ , R ₃ die

are switched on, the evaporator in the exhaust gas flow first group and the preheater .R ₄ , R ₅ , R ₆ , R ₁ die

form a second group arranged in the first place downstream of the gas turbine. Between the two groups

and if a separate feed water flow is provided , valves V ₈ and F ₉ and a pump P _{3 are connected.}

permeated. This will arrange a subset of the.

Feed water overheats and can enter the steam door

bine to be initiated. The organs cooled as a result are shown with full lines. This one

Exhaust gases then reach further heat exchangers, a gas circuit is assigned to the steam circuit

around the rest of the feed water on a low is shown with broken lines.

Preheat temperature before it is in the than The gas cycle contains a gas turbine Tg, which

Steam generator serving boiler flows back. 20 an alternator A ₂ and a Kom-

According to another embodiment example , the extinguishing agent Co, which sucks in air in parallel in the exhaust gas flow via a line α atmospheric finding, drives the evaporator. The arranged in the compressor Co komzu one of the feed water preheaters. Primed air is heated in a combustion chamber CA, which means that only part of the hot gas turbine is warmed and then enters the gas turbine Tg an evaporator E, in the tubes of which, via a valve, a portion of the water from the contact exchanger for heating the feed water passes _{directly into one of the two heat exchangers F 8} 'and a pump P _4. condenser K discharged feed water to be heated The flowing out of these heat exchangers can be directed.

Gases can then through a second heat 30 The exhaust gases then pass through two as a heat exchanger for preheating the feed water back exchanger formed feedwater Rf ₁ pass through before they are completely discharged. and Rf ₂ , which are located one behind the other in the exhaust gas flow.

The invention makes it possible, by means of which are arranged and in which the exhaust gas heats up the water turbine returning from the gas turbine exhaust gases, which have a temperature of approximately 450 ° C. at the exit from the gas capacitor K into the boiler C. The exhaust gases finally escape through a portion of the feed water in the evaporator to an outlet e into the atmosphere. To be heated to 350 ° C in the gas circuit, while the exhaust gases are arranged up to one of the valves V ₀ , F ₉ ', temperature of 100 ° C in this evaporator and Vl ₀ , F ₁₁ and V _n ,
The system works as follows: Can be outside. This means that at peak times, the steam turbine safeguards the electrical loads, an additional improvement in the generation of economic efficiency through the degree of alternating current, because in known systems the gate is A ₁ . The gas turbine is out of order. The final valve temperature of the door valves V ₀ ', F ₈ ', F ₉ ', F / _o and F ₁₁ used for preheating are closed, all the binenabgases are around 200 ° C. The other valves are open. The heating of the

The efficiency 45 achieved by the invention from the condenser K to the boiler C is far higher than that achieved by the pure summation of the feed water exclusively by generating the power of the steam turbine and the gas bleed steam that the feed water preheater R ₁ , turbine achieves can be. The flow in R ₂ , R ₃ .. -R _{1 is} once through.

The amount of heat contained in the turbine exhaust gases. During peak times, the

put into operation as much as possible in a compact heat exhaust gas turbine by adding

exchangers to preheat the feed water the next valve F ₁₂ opens so that the exhaust gases

Steam turbine is exploited, and on the other hand it will also be able to escape directly into the atmosphere and the

additionally in the steam turbine hot or superheated back pressure on the exhaust gases from the gas turbine is reduced

Steam introduced so that its performance is also increased. As soon as the gas turbine has started up, it will

when the connections are largely or completely closed, valve F _{12 is} closed so that the exhaust gases can

taps improved. fer E and the feed water preheaters Rf ₁ and Rf ₂

In the drawing are flow through for a better understanding; open the valves V ₀ ' F ₈ ',

the invention two embodiments of the inven- F ₉ ', F / _o and F _n and closes all other valves,

according to the proposed combined gas The steam taps are then closed, Steam power plant shown, namely 60 shows what the available in the steam turbine

F i g. 1 is a circuit diagram of the one embodiment performance enlarged. The water that is in the

and boiler C returns, valve V ₀ 'passes through

Fig. 2 is a circuit diagram of the second embodiment preheater Rf ₂ , the valve F ₈ ', the pump P ₃ , the

form. Valve F ₉ ', the preheater Rf ₁ , the valve F ₁₀ ' and

According to FIG. 1, a three-stage steam turbine 65 drives the pump P ₂ .

an alternator A ₁ . The steam turbine Part of the one leaving the preheater Rf ₂

has a high pressure part HP, a medium pressure part water is drawn off from the pump P ₄ and in

MP and a low pressure part BP. The steam is directed to the evaporator E , in which it is already

Preheated water is evaporated and, if necessary, superheated by the high temperature exhaust gases from the gas turbine. The steam generated in this way is introduced into the steam turbine at a suitable expansion stage via valve F _11. In the device shown for example in the drawing, this steam is introduced into the medium-pressure part of the steam turbine on the bleed line assigned to valve V _6. The pressure of the steam generated in the evaporator E can vary within sufficiently wide limits. Of course, there is a maximum steam pressure that depends on the temperature of the exhaust gases from the gas turbine.

The in F i g. The system shown in FIG. 2 differs from that of FIG. 1 in that the evaporator £ and the feedwater preheater Rf _{1 are} parallel to one another in the exhaust gas circuit. In addition, the valve V ₀ , which regulates the entry of the feed water into the preheater Rf ₂ , is arranged behind the feed water preheaters R ₁ and R ₂ , so that these preheaters remain in the feed water circuit even at peak times. Switching off the bleed steam heating this Vorwänner results in only a slight increase in the performance of the steam turbine, since the steam pressure at these bleed points is only low. In addition, the steam generated in the evaporator E can be introduced into the medium-pressure part MP of the steam turbine, specifically at the level of the last tap point (valve F ₄ ).

It can be seen that in the system shown in FIG. 1, the division of the feed water preheaters used to heat the water into two separate preheaters Rf ₁ and Rf ₂ allows mixed modes of operation. For example, at peak times it is possible to keep valve V ₀ ' closed and valves F ₀ , F ₁ , F ₂ , F ₃ and F ₈ to open. In this case, the water withdrawn from the condenser K is first heated in the preheaters R ₁ , R ₂ , R ₃ with tap steam, whereupon part of the water heated in this way is before being returned to the boiler C through the valve V ( _o and the pump P ₂ in the preheater, RZ ₁ undergoes additional heating, while the other part of the water is passed through the valve F ₈ 'and the pump F ₄ into the evaporator £ and evaporated there.

Claims (3)

Patent claims: 1. Combined gas-steam power plant, in which the steam turbine fed by a steam generator heated, for example, by a nuclear reactor provides the base load and the gas turbine provides the peak load, with a series of feed water preheaters heated by means of bleed steam being arranged at least in part parallel to feed water preheaters heated by the gas turbine exhaust gas , characterized in that one of the exhaust-gas-heated feedwater preheaters (E, Rf ₁ , Rf ₂ ) is designed in a manner known per se as an evaporator (E) , the closable outlet of which the generated and possibly superheated steam via a tapping line that is closed off from the associated regenerative heater directly back into the steam turbine. 2. Plant according to claim 1, in which the feed water preheater heated with the gas turbine waste heat are switched on one behind the other in the exhaust gas flow, characterized in that the evaporator (E) is arranged in the exhaust gas flow in the first place downstream of the gas turbine (Tg) and is traversed by a separate feed water flow . 3. Plant according to claim 1, characterized in that the evaporator (E) is arranged in the exhaust gas stream parallel to one of the feed water preheaters (Rf ₁ ) . Considered publications:
German Auslegeschrift No. 1050 609;
"Power", Volume 92, No. 9 (September 1948), pp. 64 to 71. 1 sheet of drawings 709 578/79 4.67 <& Bundesdruckerei Berlin