EP2655832A2

EP2655832A2 - Method for operating a small gas turbine assembly and small gas turbine assembly

Info

Publication number: EP2655832A2
Application number: EP11801588.2A
Authority: EP
Inventors: Franz Wimmer; Friedrich Benra; Hans-Josef Dohmen
Original assignee: Conpower Patente & Co KG GmbH
Current assignee: Conpower Patente & Co KG GmbH
Priority date: 2010-12-14
Filing date: 2011-11-23
Publication date: 2013-10-30
Also published as: WO2012079694A8; WO2012079694A3; DE102011102599A1; WO2012079694A2

Abstract

Invention relates to methods for operating a small gas turbine assembly and a small gas turbine assembly itself, comprising at least one compressor/compressor stage and at least one turbine or turbine stage, in which compressor and turbine/turbine stages act on a generator shaft to generate power. In this connection, in order to achieve a considerable increase in efficiency, according to the invention at a number N of turbines or turbine stages, a combustion chamber is arranged before each turbine or turbine stage, and the gas output from each turbine or turbine stage is introduced first into the combustion chamber of the next following turbine or turbine stage, and the gas outlet from the last turbine or turbine stage again leads back into the gas stream via a recuperation of thermal energy before entry into the first combustion chamber of the first turbine stage.

Description

The invention relates to a method for operating a small-gas turbine arrangement, as well as a small-gas turbine arrangement itself

Small gas turbine arrangement, as well as small gas turbine itself, according to the preamble of claims 1 and 11.

Micro or small gas turbines are becoming increasingly important in connection with the use of renewable energy sources or renewable raw materials. Meanwhile, techniques are known in which high process temperatures are achieved with the help of dust firing of dry biomass. With regard to the overall concept, small gas turbines are therefore important for the generation of electricity from renewable raw materials. It is also known that gas turbines currently achieve a maximum efficiency of less than 40% with the cycle processes carried out. The invention is therefore based on the object to further develop a method of the generic type to the effect that significantly higher efficiencies, and especially on the use of renewable raw materials especially

advantageous applicable technique arises. The stated object is achieved in a method of the generic type by the characterizing features of claim 1. Further advantageous embodiments of the method are specified in the dependent claims 2 to 8.

With regard to a small gas turbine itself, the stated object is achieved by the characterizing features of claim 11.

Further relevant embodiments are specified in the remaining dependent claims. This is in the claims 9 and 10 a

use according to the invention.

Core of the inventive method is that in a number of turbines, before each turbine or turbine stage a

Combustion chamber is arranged, and the gas outlet of each turbine or turbine stage is first introduced into the combustion chamber of the next turbine or turbine stage, and that the

Gas outlet of the last turbine or turbine stage in turn via a recuperation thermal energy back into the

Gas flow before entering the first combustion chamber of the first turbine stage leads.

The resulting benefits is that this leads to a significant increase in efficiency. In addition, such small gas turbine arrangements can be built extremely compact. Furthermore, a high speed

created, with means that are described in more detail below. In a further advantageous embodiment, it is stated that in the mechanical rotary engagement of the turbines or turbine stages, a compressor arrangement with M stages is provided, in which the compressor stages (1 to M) (pressure medium-locking) are connected in series, and that between each two successive compressor stages, ie behind each compressor stage, a liquid evaporator medium is injected, such that also behind the last compressor is also a final injection. This concept results in the already mentioned efficiency increases in the process.

One of the essential aspects of the invention is that the small gas turbine arrangement is configured with a plurality of compressor stages and a plurality of turbine stages, in the manner of a turbine circuit process.

In summary, the following aspects are revealed in detail in this concept.

- As a gear assembly with a central sun gear to which the generator is connected, and arranged on the star wheels compressor and turbine stages are mechanically coupled.

- One or max. two compressor or turbine stages on both sides of a starwheel shaft.

- The possibility that different speeds of compressor stages and turbine stages are given results from the arrangement or use of multiple waves.

A single-wave arrangement is nevertheless not excluded.

- Free selection as axial or radial version of the compressors or turbine stages. - A fixed selectable speed for generator (sun gear) is possible, given by the respective existing, or

desired mains frequency (usually 50 or 60 Hz).

- Power control of the small gas turbine at constant speed by means of adjustment of the vanes in the first

Compressor stage.

- One cooling after each compressor stage.

- Cooling by evaporation of evaporator medium, for example water, but preferably not exclusively to the saturation point. - Cooling energy is retained in or in the system, and represents also in this regard the cycle.

- Utilization of waste heat as heat decoupling: heating / power gas turbine (HKGT), or further use of the waste heat by means of ORC plant. - Suitable for island or grid parallel operation.

- Multi-stage compressor.

- Multi-stage turbine with intermediate combustion.

- Compressor cooling after compression.

- Used recuperation and compressor cooling together.

Although the recooling in series circuits of compressors per se state of the art. The difference according to the invention, however, consists in that

in the inventive or according to the design

Evaporator media injection is the energy consumed by the cooling system (i.e., energy removal by reducing the

Air temperature) is not discharged via the system boundary, but remains in the system (in the manner of a cycle). With the evaporator medium water, the system is easy and effective to operate. Especially with the accruing

Process temperatures of several hundred degrees Celsius.

Nevertheless, other evaporation media than water are possible.

Accordingly, it is further configured that as

Evaporator medium and liquid fuel is used, and thus injected at those injection sites at which the evaporator medium is injected.

The liquid fuel initially serves as

Evaporator media.

From the use of flux fuels at the same time as

Evaporating medium and fuel provide a number of advantages. Due to the multi-stage injection of the fuel, initially as the evaporator medium, there is a subsequent optimal air mixing of the fuel, and then ensures in the combustion chamber for optimal subsequent combustion. It is important in the case of the use of vaporizable liquid

Fuels initially as an evaporator medium that the process is controlled so that it does not come to ignition of the evaporated fuel outside of the combustion chambers.

Since the often very volatile liquid fuels have a high evaporation enthalpy, their use is also highly suitable as the evaporator medium.

In the low-temperature range, for example in the area of cooling, ORC medium (Organic Rankine Cycle) can additionally also be used.

be used, for the Nachverstromung also this

low calorific waste heat. However, this takes place in a separate cyclic process separated from the above-mentioned cyclic process.

Furthermore, it is advantageous that even before entry in the turbines or in the turbine stages evaporator medium, preferably water is temporarily injected for the purpose of turbine cleaning. With regard to the fuel for such an arrangement, basically any energy carrier in liquid and / or gaseous and / or powdered form can be injected into the combustion chambers for this process. Furthermore, it is advantageously designed that a

Capacity control of the small gas turbine or the

Small gas turbine arrangement by an adjustment of the

Anstellwinkels the vanes takes place in at least the first compressor stage.

Furthermore, it is advantageously configured that the turbines and the compressors mechanically engage with a shaft coupled to a generator / motor arrangement, and that in a starting mode the generator is operated in the drive or motor mode and subsequently in the generator mode. So it requires only one relevant aggregate with the said

Dual function. The execution of this double function lies in the unit-external elektischen switching between motor and generator operation.

Furthermore, a significant advantageous use of biomass dust-finely ground, with ash melting points above 1000 ° C, for injection into the combustion chambers by the method according to one of claims 1 to 9 given.

The reason for this is not trivial. At temperatures in this range results in a high efficiency per se. But in order to reach these temperatures, it is necessary to have a biomass available, for example a high one

Lignin content has. This is far from being anybody renewable resource reached. Slowly growing woods such as poplar and willow achieve this rather than

Short rotation crops. A special exception here is the biomass IGNISCUM (CPVO 2007/0149). Although this is also a short rotation plant with at least one harvest per year, its lignin content is surprisingly high and above all, the ash melting point is well above 1,000 ° C.

As a result, the combustion is effective, without sooting etc, and protects the turbines by avoiding or significantly reducing deposits. For this reason, said biomass is so advantageous in connection with the method and the device according to the invention.

Furthermore, this biomass Igniscum has the advantage that it is both solid or dust-fine fuel, as biogas can be obtained. The mixed fuel supply of simultaneously gas and dust from the same energy crop achieves extremely high levels

Combustion temperatures with a nearly complete

residue-free combustion.

With regard to a small gas turbine arrangement itself, the gist of the invention is that with a number of N

Turbines or turbine stages, in front of each turbine resp

Turbine stage is arranged a combustion chamber, and the

Gas output of each turbine or turbine stage is first introduced into the combustion chamber of the next turbine or turbine stage, and that the gas outlet of the last turbine or turbine stage in turn leads via a recuperation thermal energy back into the gas stream before entering the first combustion chamber of the first turbine stage.

Furthermore, there is a combination of recuperation,

unconventional compressor cooling and multi-stage

Combustion, as the essence of the invention. this causes

following:

Due to the recuperation is achieved that a much higher efficiency at the same time lower

Compression ratio is achieved.

The cooled outlet air from the last compressor stage ensures that recuperation becomes significantly more effective.

By a multi-stage combustion, the middle

Working temperature of the heat supply increased, so that the thermal efficiency is increased. Multi-stage steam turbines with reheat are known, but small gas turbines with intermediate combustion are not common. Due to the combination of recooling and recuperation not yet used with small gas turbines and a multi-stage (at least

two-stage) turbine with intermediate combustion can one

mechanical efficiency of equal to or greater than 50% can be achieved.

Another potential of the increase in efficiency lies in the still possible turbine blade cooling. Type of cooling:

Cooling at the outlet behind each compressor stage: A maximum of so much evaporator medium is introduced into the air stream that the saturation point of the air is in accordance with their

State variables is achieved behind the compressor stage.

The evaporator medium, for example water is finely injected so that it evaporates, in each case at a defined point in the process. This requires small droplets. The small size of the droplets favors the ratio of drop surface to

Drop volume. This means that the drop surface becomes large in relation to the drop volume.

Multi-stage compressors are known per se. With everyone

Compressor stage is fed to the air more energy, or the pressure of the compression process is increased. When cooling multistage compressors, the compression is kept almost isothermal and thus requires less compressor work.

The peculiarity, however, lies in the fact that with small gas turbines the cooling is used on the one hand behind the compressor stage and on the other so targeted that after the last compressor stage a recuperation is extremely effective and still the

Energy absorbed by the evaporative cooling system does not leave the system.

Also, multi-stage transmission compressors are generally known per se. In contrast, the invention provides an arrangement for small gas turbines in which the simultaneous

Placement of the turbine stages is brought together on a common transmission with the multi-stage compression. This results in a very considerable compactability of the arrangement on the one hand, but on the other hand also means that the

Overall heat balance and the overall heat management of the process is significantly optimized. In a further advantageous embodiment, it is therefore stated that in the connecting line between the (n-1) -th and the nth compressor stage, as well as directly after the n-th

Compressor stage, the injection of the evaporator medium is carried out by an injection opening arranged there, such that the evaporation already shortly before reaching the following

Compressor stage takes place, unless it is the injection port behind the last compressor stage, so that at the same time a drop erosion of the compressor is avoided.

Furthermore, it is advantageously configured that the central shaft of the generator is provided or connected with a sun gear, and that the individual shafts of both the turbines, or

Turbine stages, as well as the compressor or compressor stages are provided with gear elements and the central

Sun gear element of the generator shaft engage. This causes the very significant, already described above

Compactness of the arrangement with all the advantages already mentioned. It is advantageous here that a combined generator / motor arrangement is arranged on the central shaft. By appropriate simple electrical wiring from the outside, the generator assembly can also temporarily on engine function

be switched to start the turbine and compressor assembly first. Later, i. after starting it is switched back to generator mode.

In order to design this accordingly, it is further proposed that the turbines or turbine stages, as well as the compressors or compressor stages themselves, also be planetary around the central one

Generator assembly are arranged around, and so form a compact unit.

In a further advantageous embodiment is provided that all transmission elements are arranged in an existing housing parts but ultimately in a contiguous in the assembled state housing. The case may be jagged, but still connected. So also an effective heat management is possible. Mechanically, this one has

Compactness but also the advantage that the

Transmission elements are so compact that a friction-reduced gear engagement is possible. As an alternative embodiment, the realization of the

inventive concept but also in a serial

Compressor and turbine arrangement possible. This design relates to a single-shaft configuration of the entire arrangement. An embodiment of the invention is illustrated in the drawing and explained in more detail below.

It shows:

Figure 1: Schematic representation of the entire process.

Figure 2: embodiment of a compact arrangement with

Sun gear.

Figure 1 shows a schematic representation of the process with a multi-stage compression (here m = 4). In the first

Compressor stage 1, outside air is sucked in, and before it goes into the second compressor stage 2, is between the first and second compressor stage, the first injection site 5, which may also be designed as a conduit extension, so one

Injection space forms. Between the compressor stage 2 and 3 is a further injection site 6, and between the third and the fourth compressor stage, the further injection site 7 is placed. Also at the output of the fourth and thus here last compressor stage 4, a further injection point 8 is placed. From there it goes then pressure-locked into the first combustion chamber 13, in which gaseous and / or liquid and / or

dusty solid fuel, such as Igniscum powder is sprayed for combustion. From there it goes into the first turbine 10 and the first turbine stage 10. The output of the first turbine stage 10 then opens into the second combustion chamber

14, in which also Igniscum pulverulent ground is sprayed. In each of the combustion chambers 13 and 14, any other fuel, gaseous, liquid, or as pulverized

Solid fuel be sprayed.

As already stated above, a recuperator 12 is arranged between the output of the last compressor stage 4 after the cooling injection site 8, in which the at the second

Heat arising turbine stage to the point before entering the first combustion chamber 13, that is recuperated in the process.

The residual heat generated there is still remanufactured by a downstream ORC cycle. For this purpose, this heat is passed through a heat exchanger 32, which transfers the residual heat of the primary process in a low-temperature working fluid. From there, it goes via a turbine 31 in the ORC process, which is coupled to a second generator. The output of the turbine 31 is guided via a recuperation 33 in the ORC process and then fed to a capacitor 35, subsequently the ORC medium is guided in the ORC cycle process by means of pump 34. This is therefore an arrangement of N = 2 turbines, and also N = 2 combustion chambers.

All compressors and turbines arranged in the primary process are in mechanical operative engagement with each other. This can be realized by a common wave, or by a

Gear coupling. An example of a transmission coupling is shown in FIG. Figure 2 shows a very significant

advantageous design, by the use of a to the central arrangement of the generator 20 and on the shaft arranged sun gear has all other components such as turbines and compressors in mechanical engagement.

The compressors 1 to 4 are in this case arranged below, and the generator 20 is centrally placed around the axis (central shaft) not shown here centrally.

The compressor 1 has the adjusting means for the

Compressor vanes on. The turbines 10 and 11 are placed above the generator 20, with the first turbine 10 in the front and the second turbine in the back. Between the individual compressor stages, the water or evaporator media injection sites are placed. The

Item numbers 13 and 14 show the also structural

Integration of the two combustion chambers.

The invention thus described is a specific gas turbine cycle process that utilizes continuous water injection to recirculate the compression process, that uses the energy of the combustion gas to a very high degree in the context of recuperative heat transfer, and the multiple combustion to another

Increase in efficiency begins.

Reference numerals;

1,2,3,4 compressor

5,6,7,8 injection sites / injection rooms

10 first turbine

11 second turbine

12 recuperator in the main process

13 first combustion chamber

14 second combustion chamber

20 generator / motor in the main process

30 generator in the ORC process

31 turbine in the ORC process

32 heat exchangers

33 recuperator

34 pump

35 capacitor

Claims

Claims:

1. A method for operating a small gas turbine arrangement with at least one compressor / stage and at least one turbine or turbine stage, in which compressor and turbine / turbine stages on a generator axis to

Activation of electricity, characterized in that with a number N of turbines, before each turbine (10, 11) or turbine stage, a combustion chamber (13,14) is arranged, and the gas output of each turbine or turbine stage first in the combustion chamber of the next turbine or

Turbine stage is initiated, and that the gas outlet of the last turbine or turbine stage in turn leads via a recuperation thermal energy back into the gas stream before entering the first combustion chamber of the first turbine stage.

2. The method according to claim 1, characterized in that in the mechanical rotary engagement of the turbine or turbine stages, a compressor arrangement with M stages is provided, in which the compressor stages (1 to M)

(fluid pressure) are connected in series, and that between two consecutive each

Compressor stages, i. behind each compressor stage, a liquid evaporator medium is injected, such that also behind the last compressor is also a final injection.

3. The method according to claim 2, characterized in that the evaporator medium is water.

4. The method according to claim 2, characterized in that the evaporator medium is liquid fuel.

5. The method according to any one of claims 1 to 4,

characterized in that even before entering the turbine or turbine stages evaporator medium,

Preferably water is temporarily injected for the purpose of turbine cleaning.

6. The method according to any one of the preceding claims,

characterized in that liquid and / or gaseous and / or dust-like energy carriers are injected into the combustion chambers as energy carriers.

7. The method according to any one of the preceding claims,

characterized in that a power control of the small gas turbine or the small gas turbine arrangement is effected by an adjustment of the angle of attack of the guide vanes in at least the first compressor stage.

8. The method according to any one of the preceding claims,

characterized in that the turbines and the

Compressor mechanically engage a coupled to a generator / motor assembly shaft, and that in a starting mode, the generator in the drive or motor mode and subsequently in the operating mode of the generator in

Generator mode is operated.

9. Use of biomass dusted fine, with

Ash melting points above 1000 ° C, for injection into the combustion chambers according to the method of any one of claims 1 to 8.

10. Use according to claim 9,

characterized,

that the biomass is IGNISCUM (CPVO 2007/0149), or wood, in particular poplar and / or willow.

11. Small gas turbine arrangement with at least one compressor / stage and at least one turbine or turbine stage, in which compressor and turbine / turbine stages on a common generator axis / generator shaft to

Actively generate power generation, or are coupled to this gearbox, characterized in that at a number N turbines (10, 11) or

Turbine stages, before each turbine or turbine stage, a combustion chamber (13, 14) is arranged, and the gas outlet of each turbine or turbine stage first in the

Combustion chamber of the next turbine or turbine stage is initiated, and that the gas outlet of the last turbine or turbine stage in turn leads via a recuperation thermal energy back into the gas stream before entering the first combustion chamber of the first turbine stage.

12. small gas turbine arrangement according to claim 11,

characterized in that in the connecting line between the (n-1) -th and the nth compressor stage, as well as after the n-th compressor stage, the injection of the evaporator medium by a respective injection opening arranged there (5, 6, 7, 8) takes place, such that the evaporation takes place shortly before reaching the compressor stage, so that at the same time a drop erosion of the

Compressor is avoided.

Small gas turbine arrangement with at least one compressor stage and at least one turbine or turbine stage, in which compressor and turbine / turbine stages on a common generator axis / generator shaft to

Mechanically acting power generation, or are coupled with this transmission technology, according to claim 11, characterized in that the central shaft of the generator / motor is provided with a sun gear or connected, and that individual shafts of both the turbine or turbine stages, and the compressor or Compressor stages are provided with gear elements and engage the central sun gear element of the generator shaft.

Small gas turbine arrangement according to one of the preceding claims 11 to 13, characterized

that on the central shaft a combined

Generator / motor assembly is arranged.

Small gas turbine arrangement according to claim 12,

characterized in that the turbines or turbine stages, and the compressor or compressor stages themselves are arranged like a planet around the central generator assembly around, and thus form a compact unit.

Small gas turbine arrangement according to one of claims 11 to 15, characterized in that all

Gear elements in one of housing parts but ultimately in a mounted state

contiguous housing are arranged. Small gas turbine arrangement according to one of claims 11 to 16, characterized in that the recuperator (12) of the primary process at the outlet of the turbine (11) thermally with an ORC (Organic Rankine cycle) cycle for

Nachverstromung the low-temperature waste heat is connected