JPH11148372A - Gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high moisture gas turbine system with high efficiency and good operability by providing a flow passage bypassing a humidification tower and varying flow through the flow passage according to operation condition of the gas turbine. SOLUTION: After self sustaining is started by separating a starter, temperature of liquid phase water 16 is varied by supply of low temperature make-up water 24 and a heater 32, and is adjusted to maximize system efficiency according to each load condition. Operation speed of pumps 18, 22 is also adjusted to maximize system efficiency, referring to indication value of each thermometer. Operations of the pump 18 and the pump 22 are controlled by a controller. If a pump 25 is operated to feed water of amount equivalent to that of water flowing to air 8 referring to indication value of a water gauge 31, troubles such as overflow of a humidification tower 7 or lack of water amount can be avoided. For stopping a gas turbine, the pump 25 is operated with a valve 33 opened and a valve 34 closed. This decreases the temperature of the air 8 as low as possible and facilitates stopping of the gas turbine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine for recovering heat of a gas turbine exhaust gas and intercooling or post-cooling a compressor by using an air / steam mixture.

[0002]

2. Description of the Related Art Heated liquid water and air are brought into contact inside a humidification tower to obtain a mixture of air / steam and cooled liquid water. The former is used for heat recovery from exhaust gas, and the latter is used for heat recovery. About gas turbine system used for compressor intermediate cooling
These are described in JP-A-1-19053 and JP-A-1-31012. However, all of them are descriptions regarding static characteristics at the time of rated operation, and do not consider issues at the time of transient characteristics such as starting and load change.

[0003]

When the high-humidity gas turbine system is actually operated, during the operation from start to stop, the efficiency of the system is increased as much as possible in the components constituting the system. It is desirable to operate as follows.

A humidification system included in a high-humidity gas turbine system uses liquid-phase water having a larger heat capacity than gas and poor response characteristics. Therefore, the start-up time becomes longer. There is a problem that it costs.
Further, in a high-humidity gas turbine system, high-humidity air is used as an oxidizing agent for combustion. If the moisture content is not appropriate, a situation such as poor combustor ignition performance and unstable combustion occurs.

[0005] The object of the present invention is to devise
It is an object of the present invention to provide a high-humidity gas turbine system having high efficiency and excellent operability.

[0006]

In order to solve the above-mentioned problems, a flow path bypassing the humidification tower is provided, and the flow rate in the flow path is changed according to the operating condition of the gas turbine.

A chilled water supply system and a heater for arbitrarily changing the temperature of the liquid phase water of the humidification system and the supply / discharge amount of the humidification tower in accordance with the operation state of the gas turbine are provided.

A flow path is provided for bypassing a heat exchanger for performing intermediate cooling or post-cooling of a compressor and a heat exchanger for recovering heat of exhaust gas from a gas turbine. Vary accordingly.

Further, the heat exchanger for performing the intermediate cooling or the post-cooling of the compressor and the heat exchanger for recovering the heat of the exhaust gas from the gas turbine have a structure in which a heat transfer area can be arbitrarily changed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a system diagram showing a gas turbine system according to a first embodiment of the present invention. In the gas turbine system shown in FIG. 1, the air 3 is compressed by the compressor 2 and then enters the humidification tower 7 via the post-cooler 5. In the humidification tower 7, the air 6 is brought into countercurrent contact with the high-temperature waters 20 and 23 to be heated and humidified, and becomes high-humidity air 8. High humidity air 8 is regenerator 1
The fuel is heated in 3, reacts with the fuel 35 in the combustor 10, becomes high-temperature gas, and drives the turbine 11. The gas 12 that drives the turbine 11 exchanges heat with the regenerator 13 and the feedwater heater 15 and is released to the atmosphere.

On the other hand, high-temperature water 20, which is obtained by heating and humidifying air 6,
23 evaporates a part when it comes into contact with the air 6,
By being deprived of heat of vaporization, it becomes low-temperature liquid phase water 16 and stays in the lower part of the humidification tower 7. A part of the liquid-phase water 16 is pressurized by a pump 18 and heat-exchanged by a post-cooler 5 to remove the high-temperature water 2.
It is sprayed into the humidification tower as 0. The other liquid phase water 16 is pressurized by the pump 22, heat exchanged by the feed water heater 15, and
And spray it into the humidification tower. The amount of water corresponding to the amount transferred from the high-temperature waters 20 and 23 to the air inside the humidification tower 7 is supplied by increasing the pressure of the low-temperature supply water 24 by the pump 25.

In the present gas turbine system, the maximum efficiency is always obtained by calculating in advance the combination of the temperatures of the respective devices at which the efficiency becomes maximum under each load condition, and controlling the operation of the humidifying system so as to match the combination. Can be

The operation of the humidification system is performed as follows. Before starting the gas turbine, the pump 25 is operated while monitoring the measurement value of the water level gauge 31 to store a certain amount of water inside the humidification tower 7. This amount of water is sufficient to circulate water when the pumps 18 and 22 start operating.

The operation of the pump 18 is started simultaneously with the start of the gas turbine in order to preheat the humidification system. At this time, the pump 18 refers to the indicated values of the thermometers 26 and 29 and
And T3 are operated so as to have an appropriate temperature difference, and the amount of heat recovered from the air 4 is increased as much as possible.

After the fuel is injected, the operation of the pump 22 is started when the combustion of the combustor is confirmed. The pump 22 refers to the indicated values of the thermometers 28 and 30 similarly to the pump 18 and
Is operated to increase the amount of heat recovered from.

After the starter is disconnected and the self-sustaining operation is started, the temperature of the liquid phase water 16 is changed by injecting the low-temperature make-up water 24 and the heater 32 so that the system efficiency is maximized according to each load condition. I do. Similarly, pumps 18 and 2
The operation speed 2 is also adjusted so as to maximize the system efficiency by referring to the indicated value of each thermometer. The operation of the pump 18 and the pump 22 is controlled by a controller (not shown). The pump 25 refers to the indicated value of the water level
If the operation is performed so as to replenish the water equivalent amount that shifts to, it is possible to avoid a situation such as overflow of the humidification tower or a shortage of water.

When the gas turbine is stopped, the valve 33
Is opened, the valve 34 is closed, and the pump 25 is operated. This is to reduce the temperature of the air 8 as much as possible to make it easier to stop the gas turbine.

FIG. 2 is a system diagram showing a gas turbine system according to a second embodiment of the present invention. Only the differences between the embodiment of FIG. 2 and the embodiment of FIG. 1 will be described, and the features thereof will be described.

In the embodiment shown in FIG. 2, a system for supplying a part of the compressor discharge air 4 to the combustor 10 without passing through a humidifying system is provided, and the air flow rate flowing through the system is controlled by a valve 36, 3
7 is characterized in that it can be changed arbitrarily by using. That is, when the temperature of the high-humidity air 8 is to be increased or the contained moisture is to be reduced in order to improve the ignitability of the combustor and the combustion stability, the valves 36 and 37 are operated to provide the post-humidification. The flow rate of the air passing through the cooler 5 and the humidification tower 7 can be reduced. Therefore, the operability of the system can be improved.

FIG. 3 shows a third embodiment of the present invention. FIG.
Only the differences between the embodiment of FIG. 1 and the embodiment of FIG. 1 will be described, and the features thereof will be described.

The embodiment shown in FIG. 3 is characterized in that a flow path bypassing the post-cooler 5 and the feed water heater 15 is provided, and the bypass flow rate can be changed by valves 38, 39, 40 and 41. There is. That is, the amount of heat exchanged in the post-cooler 5 and the feedwater heater 15 is changed in accordance with the gas turbine operation state, and each temperature of the humidification system is changed so that the efficiency is maximized. Therefore, the efficiency of the system can be improved.

FIG. 4 shows a fourth embodiment of the present invention. FIG.
Only the differences between the embodiment of FIG. 1 and the embodiment of FIG. 1 will be described, and the features thereof will be described.

FIG. 4 shows an example of a structure in which the post-cooler 5 or the feed water heater 15 in the gas turbine system of FIG. 1 has a structure capable of changing the heat transfer area. In FIG. 4, reference numeral 43 denotes a fluid to be heated (the liquid phase water 1 in FIG. 1).
9 or 21), and the heat transfer tubes 44, 45, 46, 4
The heating fluid 42 (the air 4 or the exhaust gas 14 in FIG. 1) is heated by passing through 7, 48, 49, and 50.

To minimize the heat transfer area, open the valve 51,
When the valve 52 is closed and maximized, the valves 51, 53, 55
, And the valves 52, 54, 56 may be opened, and an intermediate state may be taken. That is, the amount of heat exchanged in the post-cooler 5 and the feed water heater 15 is changed in accordance with the gas turbine operation state while keeping the flow rate constant, so that each temperature of the humidification system is changed so that the efficiency is maximized. be able to. Therefore, the efficiency of the system can be improved.

[0026]

According to the present invention, it is possible to provide a high-humidity gas turbine system having high efficiency and excellent operability in all load ranges.

[Brief description of the drawings]

FIG. 1 is a system diagram of a gas turbine system according to a first embodiment of the present invention.

FIG. 2 is a system diagram of a gas turbine system according to a second embodiment of the present invention.

FIG. 3 is a system diagram of a gas turbine system according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a post-cooler used in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Load, 2 ... Compressor, 3,4 ... Air, 5 ... Post-cooler, 6 ... Tube, 7 ... Humidifying tower, 8,9 ... High humidity air, 10 ...
Combustor, 11 turbine, 12, 14 gas, 13 regenerator, 15 feed water heater, 16, 17, 19, 21 liquid phase water, 18, 22, 25 pump, 20, 23 high temperature water , 24 ... Low temperature make-up water, 26,27,28,29,30
... thermometer, 31 ... water level gauge, 32 ... heater, 33, 34,
36, 37, 38, 39, 40, 41, 51, 52, 5
3, 54, 55 ... valve, 35 ... fuel, 42, 56 ... heated fluid, 43 ... heated fluid, 44, 45, 46, 47, 4
8, 49, 50 ... heat transfer tubes.

Claims (2)

[Claims] 1. A compressor for compressing air, a humidifying tower for humidifying the compressed air compressed by the compressor, and a humidified air humidified by the humidifying tower mixed with fuel for combustion and combustion. A combustor for generating gas, a turbine driven by the combustion gas generated by the combustor, and a circulation system for exchanging liquid-phase water in the humidification tower with the compressed air and then spraying the liquid phase water into the humidification tower. In the gas turbine having a first temperature detector for detecting the temperature of the liquid phase water before the heat exchange of the circulation system, and a second temperature detector for detecting the temperature of the liquid phase water after the heat exchange of the circulation system A temperature detector, and a controller that controls a flow rate of the liquid-phase water in the circulation system based on a signal from the first temperature detector and a signal from the second temperature detector. And gas turbine. 2. A compressor for compressing air, a humidifying tower for humidifying the compressed air compressed by the compressor, and a humidified air humidified by the humidifying tower mixed with fuel for combustion and combustion. A combustor for generating gas, a turbine driven by the combustion gas generated by the combustor, and spraying liquid phase water in the humidification tower into the humidification tower after exchanging heat with exhaust gas from the gas turbine. A first temperature detector for detecting the temperature of liquid-phase water before heat exchange in the circulation system, and detecting the temperature of liquid-phase water after heat exchange in the circulation system. A second temperature detector, and a controller that controls a flow rate of the liquid-phase water in the circulation system based on a signal from the first temperature detector and a signal from the second temperature detector. A gas turbine characterized by the above.