EP1015819A1

EP1015819A1 - Adapter armature for use in a stationary gas turbine installation

Info

Publication number: EP1015819A1
Application number: EP98954140A
Authority: EP
Inventors: Thomas Weber
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1997-09-18
Filing date: 1998-09-07
Publication date: 2000-07-05
Also published as: DE19741197C1; CN1268215A; US6205767B1; WO1999014533A1; JP2001516850A

Abstract

The invention relates to an adapter armature for use in a stationary gas turbine installation (1) which is provided with a compressor (4), a turbine (6), a combustion chamber (9) and an external pressure-loaded fluidized-bed furnace (28). The inventive adapter armature is fitted between the turbine (6) and the burner (9), and can be used to run various operating modes of the gas turbine installation (1) by virtue of various controllable inlets and outlets (32 to 35).

Description

description

Adapter fitting for use in a stationary gas turbine system

The invention relates to an adapter fitting for use in a stationary gas turbine system, which is provided with a compressor, turbine, combustion chamber and an external pressure-charged fluidized bed furnace.

Conventional gas turbines are suitable for use in power plants, in which a pressure-charged fluidized-bed furnace is used to generate the hot flue gas instead of the combustion chamber. For this purpose, conventional gas turbine systems with two externally flanged combustion chambers can be used, whereby for the connection of the gas turbines to the pressure-charged fluidized bed firing system only the two combustion chambers have to be removed and replaced by a connection fitting for the fluidized bed firing system. This connection fitting can be, for example, a concentric double-pipe arrangement in which the flue gas originating from the fluidized bed furnace is passed to the gas turbine in the inner pipe and the compressed process air generated by the compressor of the gas turbine system is passed to the fluidized bed combustion system in the outer annular space.

The disadvantage of the low turbine inlet temperature of the flue gas in such fluidized bed systems is eliminated by a further development in which part of the coal introduced is gasified and this low-calorific fuel gas is used for further heating of the fluidized bed smoke gas before it enters the turbine.

In configurations that have already been tried and tested for such a gas turbine with a pressure-charged fluidized-bed furnace, this is the case The low-calorific fuel gas is supplied at a high temperature level by mixing the hot flue gases from the pressure fluidized bed with compressed air from the compressor outlet of the gas turbine system and using them as combustion air. The air inlet temperature at these burners is around 760 ° C.

Various problems arise due to this configuration:

- High NO _x values are to be expected when burning with hot combustion air.

- Difficulties arise in the combustion of natural gas on the one hand and low-calorific coal gas on the other hand with a single combustion chamber which is operated at a high air inlet temperature.

- The fluidized bed flue gas can carry ash particles which can melt when passing through the flame while the coal gas is being fired. - Elaborate hot gas fittings are necessary.

- Protecting the gas turbine against accidental startup by fluidized bed flue gases is problematic.

In the prior art, burner types have already been developed which are designed for the combustion of low-caliber synthesis gas with hot combustion air and at the same time acceptable NO _x emissions. However, the problems with the melting of ash particles, the use of expensive hot gas fittings and the heat losses caused by the use of concentric pipes remain unsolved due to the cooling of the inside of the flue gas.

To solve these problems, the invention proposes an adapter fitting with the attachment in the characterizing part of claim 1. given characteristics. This adapter fitting is characterized by

a housing which can be used between a combustion chamber connecting flange and a combined connecting flange for the process air compressed by the compressor and for the flue gas leading to the turbine,

a first line connection on the housing for attachment to the combined connection flange with an inlet for the process air compressed by the compressor and with an outlet for the flue gas,

a second line connection on the housing for attaching the combustion chamber connecting flange with an inlet for the flue gas originating from the combustion chamber and with an outlet for the process air compressed by the compressor,

a third line connection with an inlet for flue gas originating from the fluidized bed furnace, and

- A fourth line connection with an outlet for the discharge of compressed process air for fluidized bed firing and / or a coal gasification plant, wherein

- The outlets for the compressed process air are connected to the inlet thereof and can be opened and closed alternately via closing members, and

- A flow channel is provided between the burner-side inlet for the flue gas and its outlet to the turbine, which is connected to the inlet for the flue gas originating from the pressure vortex firing for admixing it with the burner flue gas via at least one closing element which can be activated and closed.

By designing this adapter fitting according to the invention, conventional gas turbines with external combustion chambers can be used. The adapter fitting is inserted between the actual gas turbine and the respective combustion chamber. puts. The intended connection of the inlet for the flue gas originating from the fluidized bed furnace with the flow channel between the burner-side inlet for the burner flue gas and its outlet to the turbine enables hot flue gases to be injected from the fluidized bed furnace downstream of the combustion chamber. So there is no passage of the flue gases from the fluidized bed furnace through the flame in the combustion chamber, which largely prevents melting of ash particles that may be carried in the fluidized bed flue gases.

By guiding the compressed process air on the inlet side, it is fed directly to the combustion chamber, which means that the combustion air can be operated at low air inlet temperatures corresponding to the compressor outlet temperature of approx. 400 ° C to 420 ° C. This brings significant reductions in NO _x emissions when using conventional type burners.

Due to the design of the adapter fitting according to the invention, compressed process air can also be discharged simultaneously to the fluidized-bed furnace and / or a coal gasification plant, as a result of which no separate plant components are necessary for the supply of process air to these components.

The subclaims indicate advantageous developments of the adapter fitting according to the invention, which are discussed in the description of the exemplary embodiment to avoid repetition.

Further features, details and advantages of the invention also result from this description which now follows, in which an embodiment of the subject matter of the invention is explained in more detail with reference to the accompanying drawings. Show it: WO 99/14533 PCTYDE98 / 02641 "-

5 Figure 1 is a schematic section of an adapter fitting in its position between the gas turbine system and the combustion chamber, and

Figure 2 shows a section through the adapter fitting according to the

Section line II-II according to FIG. 1.

In Fig. 1, the actual gas turbine system 1 is shown only in a small section, which shows a combined connection flange 2. This has a ring mouth 3 for the compressed process air brought in by the compressor 4 and a concentrically located insert line 5 for the hot flue gas flowing to the turbine 6.

The adapter fitting 7 is placed between the combined connecting flange 2 and a connecting flange 8 of a combustion chamber 9. The connecting flange 8 of the combustion chamber 9 has an external ring line 10 with an opening which is open towards the connecting flange 8 and which leads to the head 11 of the burner chamber 9. The process air is led through the ring line 10 to the burners 12 in the head 11 of the combustion chamber 9, where it is used for the combustion of natural gas or synthesis gas. The combustion process is indicated by the flames 14. The interior 13 of the conventional combustion chamber 9 is formed by a pot insert 16 arranged concentrically in the burner housing 15. Towards the connecting flange 8, this pot insert 16 forms an opening 17 for the hot flue gas generated by the combustion chamber 9.

1 and 2, the housing 18 of the adapter fitting 7 is essentially designed as a pot with a cylinder-jacket-shaped outer wall 19, a base 20, a cover 21 and a concentrically arranged ring insert 22. The housing 18 basically has a first line connection 23 with which the adapter fitting on the combined Niert connection flange 2 is attached. With a second line connection 24, the housing 18 is attached to the connecting flange 8 of the combustion chamber 9. Third and fourth line connections 25, 26 are with the flue gas discharge line 27, which is only indicated as lines, of the pressure-charged fluidized bed furnace 28 or the process air supply 29 to this fluidized bed furnace 28 and to a coal gasification plant 30, which may be present. Fluidized bed furnace 28 and Coal gasification system 30 are also only indicated in the form of a block diagram by rectangles in FIG. 1. The third and fourth line connections 25, 26 are located at diametrically opposite positions of the adapter fitting 7 and are each formed by attached rectangular tubes, as can be seen from an overview of FIGS. 1 and 2.

Inlets, outlets and outlets of the adapter fitting are explained below, which are represented by arrows in FIGS. 1 and 2. The first line connection 23 is provided with an inlet 31 for the process air compressed by the compressor 4. The second line connection 24 has an inlet 32 for the flue gas flowing out of the combustion chamber interior 13 and an outlet 33 for the process air generated by the compressor. Furthermore, an inlet 34 for the flue gas originating from the fluidized bed furnace and an outlet 35 for discharging compressed process air to the fluidized bed furnace 28 and to the coal gasification plant 30 are provided at the third line connection 25.

In a manner yet to be explained in more detail, the two outlets 33, 35 for the compressed process air are connected to their inlet 31 together and can alternately be opened and closed by closing members 36. Furthermore, through the ring insert 22, a flow channel 37 is centered in the housing 18 between the burner-side inlet 32 for the flue gas and its outlet 38 at the first line connection 23 to the turbine intended. The flow channel 37 has a passage 39 up to the inlet 34 at the third line connection 25, as a result of which flue gas originating from the fluidized bed furnace can be mixed with the combustion chamber flue gas. The passage 39 and the inlet 34 at the third line connection 25 can be opened and closed by a closing element 40 to be explained in more detail.

As can be seen from FIGS. 1 and 2, an inlet space 42 is formed between the inlet 34 and the passage 39 for the flue gas originating from the fluidized bed furnace in the annular space formed between the outer wall 19 and the ring insert 22. On the other hand, an outlet space 43 is provided in the annular space, which creates the connection between the two outlets 33 and 35 and the inlet 31 for the compressed process air. The inlet space 42 and the outlet space 43 are separated from one another by radially extending partition walls 44, 45 in the annular space, the inlet space 42 taking up a circumferential angle UE which is approximately 40 ° greater than the circumferential angle UA of the outlet space 43, since the fluidized bed flue gas has a larger volume flow and mass flow than that Combustion air has.

The design and arrangement of the individual inlets and outlets are discussed in more detail below. Thus, the inlet 31 for the process air brought in by the compressor 4 is formed by a row of holes 46 arranged in a circular arc in the base 20 of the housing 18. The row of holes runs along the wall of the ring insert 22 over the circumferential angle UA of the outlet space 43. Aligning axially with these holes 46, the cover 21 of the housing 18 also has holes 47 which form the outlet 33 for the compressed process air. Furthermore, a row of holes 48 is provided in the outer wall 19 of the housing 18 facing the fourth line connection 26, which holes 48 define the outlet 35 for the compressed process form air. A series of holes 49 are also diametrically opposite in the outer wall of the housing 18, which form the inlet 34 for the flue gas arriving from the fluidized bed furnace 28. Holes 50 in the part of the ring insert 22 facing the inlet space 42 form the passage 39 for this flue gas to the flow channel 37

As can be seen from FIG. 1, the rows of holes 47, 48 can be opened and closed by a common closing element 36, which is formed from two perforated screens 52, 53 connected to one another. These perforated diaphragms 52, 53 run along the walls of the housing carrying the holes 47 and 48, respectively, and are displaceable in the circumferential direction. As from Fig. 1 and

2, the aperture openings 54, 55 corresponding to the holes 47 and 48 in the aperture plates 52, 53 are arranged in such a way that, when the cover openings 55 are completely covered, for example, the aperture openings 55 in the aperture plate 53 with the holes 48 (fitting position in FIG 1 and 2) the diaphragm openings 54 of the perforated diaphragm 52 do not align with the holes 47 of the outlet 33. Outlet 33 is thus closed, whereas outlet 35 is fully open. When the closing member 36 is rotated in the circumferential direction, the holes 48 are closed successively, whereas the holes 47 are opened successively until finally in the other end position (not shown) of the closing member 36, the outlet 33 is fully opened and the outlet 35 is completely closed. By operating the locking device

36 achievable operating states are discussed in more detail at the end of the description.

The closing member 40, which opens and closes the inlet 34 and the passage 39, in turn has two perforated apertures 56, 57, which are used to open or close the holes 49, 50. The diaphragm openings 58, 59 in the perforated diaphragms 56, 57 are arranged relative to one another such that in the one end position (Fig. 1, 2) all holes 49, 50 are fully open. By turning the closing member 40, the holes 49, 50 are successively closed by the perforated diaphragm 56, 57 until smoke gas can no longer pass through.

Finally, it should be pointed out that in the inlet space 42 for the flue gas originating from the fluidized bed furnace 28, baffles 60 are arranged for the flow guidance of the flue gas. This will make a smaller one

Pressure loss and good mixing of the fluidized-bed flue gas with the flue gas flowing out of the combustion chamber 13 are achieved.

With respect to ^"the one used for the adapter fitting 7 materials should be noted that the ring insert 22 to high temperature as the inner shell is executed. It thus can absorb the thermal stress of the fitting. The outer shell formed by the outer wall is made of low-alloy cast steel and increases the mechanical Load on the adapter fitting 7. It therefore forms the actual "backbone" of the fitting.

Due to the two closing members 36, 40, the adapter fitting 7 offers variable operating and control options, which are to be discussed as follows:

Standard operation of the gas turbine system only with natural gas or synthesis gas: the inlet 34 and the passage 38 are closed by appropriate adjustment of the closing member 40. The flue gas path from the fluidized bed furnace 28 into the turbine 6 is thus blocked. Furthermore, the closing member 36 is adjusted so that outlet 33 is fully open and outlet 35 is completely closed. The over the always open inlet 31 in the Compressed process air flowing through the outlet space 43 thus reaches the burners 12 completely and is used there for the combustion of the synthesis gas supplied from the coal gasification system 30 via the feed line 61 or of the natural gas made available via a feed line 62. At the same time, the process air flowing in the ring line 10 to the burner head 11 cools the combustion chamber 9.

Exclusive fluidized bed firing mode: The closing member 40 is set so that the inlet 34 and the passage 39 are completely open. Closing member 36 is positioned so that outlet 33 is fully closed and outlet 35 is fully open. Thus, on the one hand, the flue gas path from the fluidized bed furnace via the inlet space 42 and the flow channel 37 to the turbine 6 is open, as a result of which the fluidized bed flue gas is used to operate the turbine. The closure member 36 is positioned so that the outlet 33 is completely closed and the outlet 35 is fully open. The compressed process air thus passes completely to the fluidized bed furnace 28 and is used there for combustion.

Combined operation with fluidized bed firing, coal gasification and synthetic gas burner: The closing member 36 is arranged in a central position, so that both the outlet 33 and the outlet 35 are partially open. Care should be taken to ensure that a similar pressure drop is produced via both outlets 33, 35, so that the compressed process air does not only flow through one of the two outlets. In particular, in the case of combined operation, constructive measures must be provided in the area of the outlet 33 towards the combustion chamber 9 so that a corresponding pressure drop is caused. Towards the fluidized bed furnace 28, a relatively high back pressure is caused by the fluidized bed, gas cleaning and a usually existing a fluid bed cooler. In any case, the compressed process air reaches the combustion chamber 9 on the one hand and the fluidized bed furnace 28 on the other hand, thus serves on the one hand for combustion in the fluidized bed furnace 28 and on the other hand for the operation of the combustion chamber 9 The power distribution between fluidized bed furnace 28 and combustion chamber 9 can be adjusted via the outlets 33, 35. Furthermore, in this operating mode, the closing element 40 is positioned in the open position, so that the flue gas path from the fluidized bed furnace 28 to the flow channel 37 is open. The fluidized-bed flue gas arriving at a temperature of approximately 750 to 950 ° C. is mixed with the combustion chamber flue gas (temperature approximately 1400 ° C.) in the flow channel 37, so that a flue gas temperature at the inlet to the turbine 6 of approx. 1000 to 1200 ° C.

Rapid shutdown of the gas turbine:

In the event of a malfunction, for example when the gas turbine is shedding loads, it must be protected against start-up by the fluidized bed flue gases. For this purpose, the closing member 40 is to be provided with a quick adjustment. In an emergency quick close outlet 35 is now closed by the closing member 36 and outlet 33 is fully opened. The entire compressed process air thus flows into the combustion chamber 9, where, however, the fuel supply is severely throttled or completely interrupted at the same time. The excess process air flows through the combustion chamber 9 and the flow channel 37 through the turbine 6, where, however, no power is generated in the combustion chamber 9 due to the lack of heating. At the same time inlet 34 and passage 39 are quickly closed, so that no more flue gas can get from the fluidized bed furnace 28 to the turbine 6. The turbine 6 cannot run up.

Claims

claims

1. Adapter fitting for use in a stationary gas turbine plant (1), which is provided with a compressor (4), turbine (6), combustion chamber (9) and external pressure-charged fluidized-bed furnace (28), g e k e n n z e i c h n e t d u r c h

a housing (18) which can be used between a combustion chamber connecting flange (8) and a combined connecting flange (2) for the process air generated by the compressor (4) and for the flue gas leading to the turbine,

- a first line connection (23) on the housing (18) for attachment to the combined connecting flange (2) with an inlet (31) for the process air generated by the compressor (4) and with an outlet (38) for the flue gas,

- A second line connection (24) on the housing (18) for attaching the combustion chamber connecting flange (8) with an inlet (32) for the flue gas originating from the combustion chamber (9) and with an outlet (33) for the process air generated by the compressor ,

- A third line connection (25) with an inlet (34) for flue gas originating from the fluidized bed furnace (28), and

- A fourth line connection (26) with an outlet (35) for the discharge of compressed process air for fluidized bed firing (28) and / or a coal gasification plant (30),

- The outlets (33, 35) for the compressed process air ic the inlet (31) of which are in connection and can be opened and closed alternately via closing members (36), and

- A flow channel (37) is provided between the burner-side inlet (32) for the flue gas and its outlet (38) to the turbine (6), which is connected via at least one and controllable closing member (40) is connected to the inlet (34) for the flue gas originating from the fluidized bed furnace for admixing it to the combustion chamber flue gas.

2. Adapter fitting according to claim 1, so that the housing (18) is essentially designed as a pot with an outer wall (19), a bottom (20), a cover (21) and a concentrically arranged ring insert (22).

3. Adapter fitting according to claim 2, characterized in that on the outer wall (19) at diametrically opposite positions of the inlet (34) for the flue gas originating from the fluidized bed furnace (28) and the outlet (35) for the fluidized bed furnace ( 28) and / or outgoing process air to the coal gasification plant (30) are arranged, the annular space formed between the outer wall (19) and the ring insert (22) through intermediate walls (44, 45) into an inlet space (42) for the flue gas and an outlet space (43) are divided for the process air.

4. Adapter fitting according to claim 3, so that the inlet space (42) occupies a preferably 15 ° to 25 ° larger circumferential angle range (UE) than the outlet space (43).

5. Adapter fitting according to one of claims 2 to 4, d a d u r c h g e k e n n z e i c h n e t that the inlet (31) for the process air in the bottom (20) of the housing (18) is arranged and opens into the outlet space (43) for the process air.

6. Adapter fitting according to one of claims 2 to 5, characterized in that the off let (33) for the process air to be removed to the combustion chamber (9) is arranged in the cover (21) of the housing (18).

7. Adapter fitting according to one of claims 2 to 6, characterized in that a passage (39) in the ring insert (22) between the flow channel (37) for the combustion chamber flue gas and the inlet space (42) for the flue gas originating from the fluidized bed furnace. is provided.

8. Adapter fitting according to one of claims 1 to 7, d a d u r c h g e k e n n z e i c h n e t that all inlets (31, 32, 34), outlets (33, 35) and the passage

(39) are designed as rows of openings (46-50) in the corresponding walls (19, 20, 21, 22) of the housing (18), which can be opened and closed by means of displaceable perforated screens (52, 53; 56, 57) are.

9. Adapter fitting according to claim 8, characterized in that the perforated diaphragms (52, 53) for the two process gas outlets (33, 35) in the outlet space (43) are coupled to one another such that a control of the one outlet (33 or 35) a control of the other outlet (33 or 35) causes.

10. Adapter fitting according to claim 8 od <§r 9, characterized in that the two perforated screens (56, 57) of the inlet (34) and the passage (39) for the flue gases originating from the fluidized bed furnace (28) are coupled in such a way that inlet (34) and passage (39) can be opened and closed simultaneously.

11. Adapter fitting at least according to claim 3, characterized in that in the inlet space (42) for the flue gas originating from the fluidized bed firing (28) Baffles (60) are arranged for the flow guidance of the flue gas.