JP2001090949A - Partial regeneration two-fluid gas turbine with reduced pressure loss and its combustor - Google Patents

Abstract

[PROBLEMS] To significantly increase the bleed air without increasing the driving steam pressure, thereby greatly increasing the air / steam suction ratio, and exergy loss of the exhaust heat recovery unit. The present invention provides a partially regenerative two-fluid gas turbine capable of reducing power generation and improving power generation efficiency, and a combustor thereof. SOLUTION: A partly regenerating two-fluid in which a part of air compressed by a compressor 2 is extracted before a combustor 3, mixed with steam, heated by turbine exhaust heat, and then injected into the combustor. In a gas turbine, an extraction port a of a compressor and an air introduction port c in a combustor are provided, combustion air of the combustor is directly introduced into the combustor, and the remaining compressed air is extracted from the extraction port a and mixed with steam. Then, after being heated by the exhaust heat of the turbine, it is introduced into the air introduction port c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine power generation system for generating power and generating steam, and more particularly to a partially regenerative two-fluid gas turbine for injecting steam into a gas turbine and a combustor thereof.

[0002]

2. Description of the Related Art A two-fluid cycle gas turbine for injecting steam into a gas turbine is disclosed in, for example, Japanese Patent Publication No. Sho 54-3.
No. 4865, "Two Working Fluid Heat Engine" is known. As shown in FIG. 5, this two-fluid cycle gas turbine (hereinafter referred to as the chain cycle from the inventor's name) has a throttle valve 1, a compressor 2, a combustion chamber 3, a water treatment device 4, a pump 5, a heat Exchanger 6, turbines 7, 8,
The compressor 9 is composed of a condenser 9 and the like, and the air sucked from the atmosphere is compressed by the compressor 2 and supplied to the combustion chamber 3.
The fuel is burned with the compressed air to generate high-temperature combustion gas, which drives turbines 7 and 8 to drive the compressor 4 and the load, and further uses the combustion gas leaving the turbine to generate heat in the heat exchanger 6. The steam is generated, the water is collected by the condenser 9 and released into the atmosphere. In the chain cycle, the steam S generated in the heat exchanger 6 is injected into the combustion chamber 3 to increase the flow rate of the combustion gas flowing into the turbine and increase the specific heat of the combustion gas. It has the characteristic that can increase.

The inventor of the present invention has filed and applied for Japanese Patent Publication No. 8-26780 as a two-fluid cycle gas turbine having an improved chain cycle.

As shown schematically in FIG. 6, a "partially regenerating two-fluid gas turbine" disclosed in Japanese Patent Publication No. 8-26780 has a compressor 2 for compressing air and a combustor 3 for burning fuel.
A gas turbine comprising: a turbine 7 driven by combustion gas to drive a compressor; a mixer 10 for increasing the pressure of compressed air using steam S (saturated steam) as a driving source and mixing the two fluids; A superheater 6 provided downstream to heat the mixed gas by the mixer 10 with turbine exhaust.
An exhaust heat boiler 12 provided downstream of the superheater 6 for evaporating water using turbine exhaust as a heat source, and air for guiding a part of the compressed air from the compressor 2 to the combustor 3 and the rest to the mixer 10. A line 13, a main steam line 14 for sending a part of the steam S from the exhaust heat boiler 12 to the mixer,
0, and a mixed gas line 15 for guiding the mixed gas according to 0 to the combustor 3 via the superheater 6.

In this partially regenerating two-fluid gas turbine,
A part of the compressed air is sucked and mixed with the steam S generated by collecting the exhaust heat of the gas turbine, and the exhaust heat of the gas turbine is recovered by the superheater 6 and then injected into the combustor.
The amount of air whose temperature has been increased by exhaust heat recovery of the gas turbine,
More energy can be recovered than in the chain cycle and cycle efficiency can be improved.

FIG. 7 is an exhaust heat recovery diagram of the above-mentioned partial regeneration type two-fluid gas turbine. In this figure, the horizontal axis represents the heat exchanged with respect to the gas turbine exhaust gas, and the vertical axis represents the temperature. The abscissa specifically corresponds to the enthalpy of gas turbine exhaust gas based on 0 ° C. In this figure, the gas turbine exhaust gas is from about 550 ° C. to about 150 ° C.
Water is heated to the saturation temperature with that amount of heat,
It evaporates at the saturation temperature to become saturated steam, and is further heated to become superheated steam.

[0007] The heat recovery after evaporation is heating only steam in the chain cycle, while heating the mixed gas of steam and air in the partially regenerating two-fluid gas turbine. Therefore, in FIG. 7, the temperature rises due to the mixing of the compressed air, and the flow rate of the mixed gas further increases, so that the temperature rise gradient becomes gentle. As a result, the recovery of the effective energy corresponding to the area shown by hatching in FIG. 7 is larger than that of the chain cycle, and the cycle efficiency is improved accordingly.

[0008]

However, in the partially regenerative two-fluid gas turbine shown in FIG. 6, it is necessary to increase the amount of compressed air sucked by the mixer 10 in order to improve the cycle efficiency. However, the bleed port of the compressor 2 (a
Point) and the introduction port (point b in the figure) of the combustor 3 are structurally close to each other, and the pressure loss (hereinafter, pressure loss) therebetween is only about several hundred mmAq. The pressure loss in the vessel 6 is several thousand mmAq (for example, about 3000 mmA
q). For this reason, in order to increase the bleed air, it is necessary to greatly increase the boosting performance of the mixer, and it is necessary to greatly increase the driving steam pressure supplied to the mixer.

That is, it is necessary to increase the air / steam suction ratio by overcoming the pressure loss of the exhaust heat recovery heat exchanger (superheater 6) and the static pressure of the introduction port to the combustor by the mixer. The pressurizing performance of the vessel was limited, and it was difficult to significantly increase the suction ratio.

The present invention has been made to solve such a problem. That is, an object of the present invention is to significantly increase the bleed air without increasing the driving steam pressure, thereby greatly increasing the air / steam suction ratio and reducing the exergy loss of the exhaust heat recovery unit. Decrease
An object of the present invention is to provide a partially regenerative two-fluid gas turbine capable of improving power generation efficiency and a combustor thereof.

[0011]

The sum of the pressure loss of the combustor itself, that is, the pressure loss of the swirl constituting the combustor and the pressure loss due to the increase in the flow velocity during combustion in the combustion zone is usually several thousand m.
mAq (eg, about 3000 mmAq). The present inventor has noticed that the suction ratio can be increased by bypassing this portion. The present invention is based on such a new finding.

That is, according to the present invention, a compressor (2)
A part of the air compressed in is extracted before the combustor (3),
In a partially regenerative two-fluid gas turbine that mixes with steam and heats it with turbine exhaust heat, this mixed gas is injected into a combustor. In a partially regenerative two-fluid gas turbine, an air introduction port c is provided at a position that bypasses a bleed port a of the compressor and a combustion zone. The combustion air of the combustor is directly introduced into the combustor, the remaining compressed air is extracted from the extraction port a, mixed with steam, heated by turbine exhaust heat, and then introduced into the air introduction port c. Pressure-reduction type partially regenerating two-fluid gas turbine is provided.

According to a preferred embodiment of the present invention, a mixer (22) for mixing the compressed air and steam extracted from the extraction port (a) with the mixed gas heated by the turbine exhaust heat and then supplied to the air inlet port c mixed gas line (2
4).

According to the configuration of the present invention, the bleed port a
Bleed air extracted from the above can be mixed with steam, heated and directly introduced from the air introduction port c, bypassing the combustion area, whereby the pressure loss of the line extracted and introduced becomes equal to the pressure loss passing through the combustion area. Become. Therefore, the pressure loss due to combustion and the pressure loss passing through the superheater become parallel, and the suction ratio (air / steam ratio) of the mixer can be increased without increasing the boosting performance of the mixer.
Can be greatly increased. As a result, compressed air that can be used for exhaust heat recovery can be increased, and as a result, cycle efficiency can be increased.

According to the present invention, the combustion zone (31a)
And a combustor liner (3) having a dilution zone (31b) inside.
2) and a bleed port (3
4) and an air introduction port (36) directly communicating with the dilution area of the combustor liner, whereby a part of the compressed air is extracted from the extraction port, and a mixed gas of the compressed air and the steam is introduced into the air. A combustor for a gas turbine, wherein the combustor is directly introduced into a dilution zone from a port.

With this combustor, the bleed port (34)
A large amount of compressed air is extracted from the air inlet port (36)
A large amount of mixed gas (air and steam) can be introduced with low pressure loss by bypassing the combustion zone.

Furthermore, according to the present invention, the combustion zone (31a)
And a combustor liner (3) having a dilution zone (31b) inside.
2) and a partition (39) partitioning between the combustor casing (38) and the combustor liner at an intermediate position between the combustion zone (31a) and the dilution zone (31b), and the combustor liner in the dilution zone (31b). Is an opening (32) communicating with a gap with the casing.
a), whereby the combustion air is supplied to the combustion area side of the partition wall and directly flows into the combustion area, and the mixed gas of the compressed air and the steam is supplied to the dilution area side of the partition wall to open the opening (32a ) To a dilution zone.

According to this configuration, a large amount of compressed air is extracted from the extraction port, and a mixed gas of compressed air and steam is supplied to the dilution area side of the partition wall, and flows into the dilution area through the opening (32a) with low pressure loss. be able to.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. Note that the same reference numerals are used for common parts in each drawing. FIG. 1 is an overall configuration diagram of a partially regenerating two-fluid gas turbine with reduced pressure loss according to the present invention. In this figure, a partially regenerating two-fluid gas turbine according to the present invention includes a compressor 2 for compressing air A, a combustor 3 for burning fuel F, and a turbine 7 driven by combustion gas E to drive the compressor 2. , A superheater 6 provided downstream of the turbine 7, and an air line 13 for guiding a part of the compressed air from the compressor 2 to the combustor and the rest to the mixer.

The partially regenerative two-fluid gas turbine of the present invention further includes a mixer 22 for mixing the compressed air and steam extracted from the extraction port a of the compressor with steam, and heating the mixed gas by the mixer 22 with turbine exhaust heat. And a mixed gas line 24 leading to the air introduction port c. The superheater 6 provided downstream of the turbine 7 further heats the mixed gas from the mixer 22 with turbine exhaust.

In this embodiment, the mixer 22 is an ejector that is driven by the saturated steam S supplied from the exhaust heat boiler 12 through the main steam line 14 and sucks compressed air. In the present invention, the mixer 22 is not limited to the ejector, and may be another type of mixing device having a small pressure loss as long as the backflow of the compressed air in the air line 13 can be prevented. The mixed gas line 24 heats the mixed gas (air and steam) by the mixer 22 with the turbine exhaust heat in the superheater 6,
It leads to the air introduction port c. Also. The air introduction port c is located at a position bypassing the combustion zone of the combustor,
That is, it is provided at a position where the static pressure is lower by about several thousand mmAq (for example, about 3000 mmAq) than the bleed port a of the compressor.

With the above-described structure, a large amount (for example, 60 to 70% of the whole) of compressed air is extracted from the extraction port a of the compressor, and the remaining air is directly introduced into the combustor as combustion air, and the compressed air is extracted. After the air is mixed with the steam and heated by the turbine exhaust heat, it can be introduced into the air introduction port c.
According to this configuration, the pressure loss of the line to be extracted and introduced is:
Since the pressure loss is equal to the pressure loss passing through the combustion zone, the pressure loss due to combustion and the pressure loss passing through the superheater are paralleled, and the suction ratio (air / steam ratio) of the mixer is greatly increased without increasing the boosting performance of the mixer. Can be increased.

FIG. 2 is an exhaust heat recovery diagram of FIG. In this figure, the horizontal axis represents the heat exchanged on the basis of the gas turbine exhaust gas (enthalpy based on 0 ° C. of the gas turbine exhaust gas), and the vertical axis represents the temperature.

In this figure, the exhaust gas of the gas turbine is
The water is cooled from about 550 ° C. to about 160 ° C., and the heat is used to heat the water to a saturation temperature, evaporate at the saturation temperature to a saturated steam, and further heat to a superheated steam.

As is clear from FIG. 1, the exhaust heat boiler 12
Is supplied with water (for example, about 50 ° C.), and a part of the water is supplied as low-pressure (for example, about 20 kg / cm 2 g) saturated steam.
It is supplied to a mixer 22 via a steam drum, the main steam line 14. This vapor evaporation line is approximately 200 in FIG.
It is a constant temperature line of ° C.

Next, in the subsequent heating in the superheater 6, since a large amount of air is mixed with the low-pressure steam in the mixer 22, both the amount of air and the amount of steam are larger than before, and the temperature rise gradient is further gentle.

As is apparent from comparison of this exhaust heat recovery diagram with the conventional FIG. 7, since the air amount and the steam amount of the configuration of the present invention are both larger than those of the prior art, the temperature rise gradient of the mixed gas of steam and air is increased. Since the temperature becomes closer to the temperature gradient of the exhaust gas and the amount of evaporated water is relatively reduced, the amount of exchanged heat at the evaporation completion position is reduced. In other words, the amount of heat recovered in the mixed gas of steam and air is increased, and as a result, the energy recovery corresponding to the area shown by the diagonal lines in FIG. 2 is increased as compared with FIG. 7, and in this example, the generator end efficiency is reduced. Conventional maximum of about 3
From 9.8% to about 41.0%, a cycle efficiency of about 5
% Can be improved.

FIG. 3 is an overall configuration diagram of a gas turbine combustor according to the present invention. As shown in this figure, a gas turbine combustor 30 of the present invention has a combustion zone 31a and a dilution zone 3
1b inside and a combustion zone 31
a combustor liner 32 and an air inlet port 36 directly connected to the dilution zone 31b of the combustor liner 32. In this figure, Z-Z is the compressor 2
And the rotation center of the turbine 7.

With this configuration, a part of the compressed air is extracted from the extraction port 34, and a mixed gas of the compressed air and the steam can be directly introduced from the air introduction port 36 into the dilution zone. A large amount of mixed gas (air and steam) can be introduced with low pressure loss by extracting compressed air and bypassing the combustion area from the air introduction port 36.

FIG. 4 is another schematic diagram of a gas turbine combustor according to the present invention. The gas turbine combustor 30 of the present invention includes a combustor liner 32 having a combustion zone 31a and a dilution zone 31b inside, and a combustor casing 38 and a combustor liner at an intermediate position between the combustion zone 31a and the dilution zone 31b. And a partition wall 39 for partitioning. Further, the combustor liner 32 in the dilution zone 31b has an opening 32a communicating with a gap with the casing 38.

With this configuration, the combustion air is supplied to the combustion area side of the partition wall 39 to flow directly into the combustion area, and the mixed gas of the compressed air and the steam is supplied to the dilution area side of the partition wall 39, and is supplied through the opening 32a. A large amount of compressed air can be extracted from the extraction port, and a mixed gas of compressed air and steam can be introduced into the dilution area with low pressure loss through the opening 32a.

As described above, according to the present invention, the combination of a low-pressure-drop mixer and a low-pressure-drop bypass combustor suppresses exergy loss and increases the air / steam suction ratio efficiently and greatly. In addition, power generation efficiency can be improved.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously changed without departing from the gist of the present invention.

[0034]

As described above, the partial pressure regenerating type two-fluid gas turbine of the present invention and the combustor thereof can greatly increase the bleed air without increasing the driving steam pressure. It has excellent effects such as greatly increasing the air / steam suction ratio, reducing exergy loss in the exhaust heat recovery section, and improving power generation efficiency.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a pressure-loss reduction type partially regenerating two-fluid gas turbine according to the present invention.

FIG. 2 is an exhaust heat recovery diagram of FIG.

FIG. 3 is an overall configuration diagram of a gas turbine combustor according to the present invention.

FIG. 4 is another schematic diagram of a gas turbine combustor according to the present invention.

FIG. 5 is an overall configuration diagram of a conventional two-fluid gas turbine.

FIG. 6 is an overall configuration diagram of a partially regenerating two-fluid gas turbine of the prior application.

FIG. 7 is an exhaust heat recovery diagram of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Throttle valve 2 Compressor (compressor) 3 Combustor (combustion chamber) 4 Water treatment device 5 Pump 6 Superheater 7, 8 Turbine 9 Condenser 10 Mixer (ejector) 12 Waste heat boiler 13 Air line 14 Main steam line 15 Mixing Gas line 22 Mixer 24 Mixed gas line 31a Combustion zone 31b Dilution zone 32 Combustor liner 34 Bleed port 36 Air introduction port 38 Combustor casing A Air F Fuel S Steam E Combustion gas W Water supply

Claims (4)

[Claims] 1. A part of air compressed by a compressor (2) is extracted before a combustor (3), mixed with steam, heated by turbine exhaust heat, and then injected into the combustor. In the partially regenerative two-fluid gas turbine, an extraction port a of the compressor and an air introduction port c are provided in the combustor, combustion air of the combustor is directly introduced into the combustor, and the remaining compressed air is extracted from the extraction port a. A pressure-reduced partially regenerating two-fluid gas turbine, wherein the gas is mixed with steam, heated by turbine exhaust heat, and then introduced into an air introduction port c. 2. A mixer (22) for mixing the compressed air and steam extracted from the extraction port (a) with steam, and a mixed gas line (24) for guiding the mixed gas by the mixer with turbine exhaust heat and leading it to an air introduction port (c). 2. The partially regenerating two-fluid gas turbine according to claim 1, further comprising: 3. A combustor liner (32) having a combustion zone (31a) and a dilution zone (31b) inside, a bleed port (34) provided upstream of the combustion zone, and a combustor liner dilution zone. And an air introduction port (36) directly communicating with the air intake port, whereby a part of the compressed air is extracted from the extraction port,
A gas turbine combustor, wherein a mixed gas of compressed air and steam is directly introduced into a dilution zone from an air introduction port. 4. A combustor liner (32) having a combustion zone (31a) and a dilution zone (31b) inside, and a combustion zone (31).
a) and a partition wall (39) partitioning between the combustor casing (38) and the combustor liner at an intermediate position between the dilution zone (31b), and the combustor liner in the dilution zone (31b) communicates with a gap between the casing and the casing. An opening (32a) for supplying combustion air to the combustion area side of the partition wall to directly flow into the combustion area, and supplying a mixed gas of compressed air and steam to the dilution area side of the partition wall; A combustor for a gas turbine, wherein the combustor flows into a dilution zone through an opening (32a).