JPS5844925B2 - Kakiyubo Irano Fukajiyousyou Kasokuhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves pressurizing the combustion air of a pressurized combustion boiler with an air compressor and guiding it into a combustion chamber to burn fuel under pressure, and the combustion gas generated here is sent to a gas turbine. The present invention relates to a load increase acceleration method in a so-called air compressor->pressure boiler->gas turbine system (hereinafter, this system will be referred to as a supercharged boiler), in which the air compressor is also driven by the turbine.

Furthermore, in order to obtain the amount of fuel that controls the load of the supercharged boiler, such as the use of steam obtained from the pressurized boiler or the power generation by a gas turbine, the amount of air sufficient to burn the fuel, and the amount of air required. Adjustment of the output of the gas turbine that drives the air compressor, and the interaction of the temperature, flow rate, and pressure of the gas at the gas turbine inlet to obtain the required output of the turbine, are carried out by introducing steam from outside the system into the air or combustion gas of this system. Alternatively, the present invention relates to a method of accelerating the load increase of a supercharging boiler to efficiently obtain a desired gas turbine output by appropriately adjusting the temperature and flow rate of gas at the gas turbine inlet by introducing water.

Conventionally, increasing the output of a gas turbine (by increasing the temperature or flow rate of combustion gas at the inlet of the gas turbine) has been carried out as follows.

(1) Increase the amount of fuel.

In other words, the amount of air supplied to the combustor is much larger than the theoretical amount of air required for combustion, so if the amount of fuel is increased, complete combustion will occur within the excess amount of air even without increasing the amount of air.
The gas temperature at the gas turbine inlet increases, the amount of combustion gas also increases, and thereby the gas turbine output also increases.

(2) If the rotation speed of the air compressor is constant, a combustion air flow rate adjustment valve is installed at the outlet of the air compressor to supply the amount of air necessary for combustion of fuel according to the output of the gas turbine, and to Increase the power of the turbine.

(3) If the air compressor can control its rotational speed, increase the rotational speed to increase the amount of combustion air and increase the amount of fuel accordingly to achieve the desired purpose.

However, in either method, the turbine output is increased after increasing the gas temperature at the gas turbine inlet, so it is difficult to rapidly increase the temperature due to constraints on the material of the gas turbine (strain and thermal stress). There are restrictions and the temperature must be gradually increased.

Therefore, a sudden increase in load could not be expected.

To solve this problem, a method is currently being used to increase the gas flow rate by injecting steam or water into the combustion gas section of the gas turbine instead of increasing the gas temperature at the gas turbine inlet to obtain the required output of the gas turbine. ing.

However, there is a problem due to the large difference in the temperature of the combustion gas at the gas turbine inlet and the temperature of the steam or water blown into it.

For example, in the case of blowing steam, the gas temperature at the gas turbine inlet is about 1000°C,
The steam temperature is about 540°C at most.

Increasing the gas turbine output only by increasing the flow rate requires a large amount of steam or water, so if the mixture ratio that achieves the objective is achieved, the turbine population gas temperature will drop significantly.

Therefore, it is not possible to rapidly increase the output of the gas turbine, and rather it has a drawback that it has poor followability to the output of the supercharging boiler.

The object of the present invention is to overcome all these drawbacks.

In particular, by injecting steam or water into the combustion air in a duct at the compressor inlet or outlet or in a wind box, or into the flame or combustion gases in the combustion chamber at the burner throat or at the combustion chamber circumferential wall. The feature is that the flow rate can be increased without reducing the temperature of the combustion gas at the gas turbine inlet, and the output of the gas turbine can be rapidly increased without any problems with strain or thermal stress on the gas turbine.

The present invention will be described below with reference to Examples.

In FIG. 1, atmospheric air is sucked in from an air intake port 1 as combustion air for fuel 5, and is pressurized by an air compressor 2 to a pressure necessary for a gas turbine 7 to obtain a required output.

This pressurized air is transferred to the conduit 1 on the air compressor inlet side before the fuel 5 is combusted in the combustion chamber of the pressurized boiler 4.
The mixture is sufficiently mixed with steam or water blown in from the conduit 10' on the inlet side of the pressure boiler, and the mixture is introduced into the pressure boiler 4 as combustion air.

Injecting steam or water into the combustion air in this way lowers the combustion temperature in the combustion chamber of the pressurized boiler 4 and reduces the amount of radiant and absorbed heat.

In addition, on the contact heat transfer surface of the pressurized boiler 4, the temperature difference Δt・
... becomes smaller, the amount of heat absorbed is reduced, the combustion gas outlet temperature of the pressurized boiler 4 is not lowered much, and the gas temperature and flow rate required for the gas turbine output can be obtained.

Alternatively, as described below, steam or water can be blown directly into the flame or combustion gas in the combustion chamber through the four ports 11 or 11'.

In this case as well, the same effect as above can be obtained.

FIG. 2 shows an example of the pressurized boiler 4.

The arrow 3 indicates a combustion air conduit led from the air compressor 2 described in FIG. 1, and is connected to the wind box 13.

In this embodiment, the steam or water inlet is placed in the vicinity of the burner 14, and the steam or water supplied from the inlet 11 is collected in the annular collecting pipe 17 and passes through the nozzle 18 to the burner 14.
around No.4, it does not inhibit combustion and lowers the combustion temperature, reducing NOx
The steam or water blown in from another air inlet 11' is collected in an annular collector pipe 19, and the steam or water is sucked into the combustion chamber 15 evenly at a suitable position to reduce the generation of steam or water. A mechanism is provided in which the air is blown into the combustion chamber from the nozzle 20 almost evenly at positions that do not inhibit combustion, lower the combustion temperature, and reduce the generation of NOx.

The combustion gas generated in the combustion chamber 15 first passes through the radiation heat transfer surface 2.
1, and then flows as shown by the arrow while being further absorbed by the contact heat transfer surface 22, and is guided from the combustion gas outlet to the gas turbine through the conduit 6 at the gas temperature, flow rate, and pressure required for the desired output of the gas turbine. .

In the figure, 5 is a fuel conduit, 23 is a refractory and a heat insulating material, 24 is a water supply pipe of a pressurized boiler, and 25 is a steam outlet of the pressurized boiler, which is used to send air to, for example, a factory.

In this embodiment, steam or water is blown into the vicinity of the burner 14 and into the combustion chamber 15, but the supercharging boiler 4
Either one may be used depending on the output conditions.

FIG. 3 shows changes over time in the gas turbine inlet gas temperature and flow rate of the supercharging boiler 4 configured as described above in comparison with a conventional system.

In the conventional method shown by curve A in FIG. 3, as shown in the required time t2, it is not possible to rapidly increase the temperature and flow rate due to material problems with the high temperature of the gas turbine.
Also, when blowing steam or water into the gas turbine inlet, there is a large difference between the gas temperature and the steam or water temperature.
It can be clearly deduced that steam or water had to be gradually injected to increase the flow rate without reducing the gas energy, ie the gas temperature, required by the gas turbine.

The vertical axis in FIG. 3 is the gas turbine inlet gas temperature and flow rate, and the horizontal axis is the required time t.

Curve A according to the conventional method is a curve with a gentle slope, and curve B according to the method of the present invention rises at a steep slope, so the difference in required time between the two is 12-1. It will be understood that a difference in acceleration occurs by .

In other words, the gas turbine inlet gas temperature and flow rate are 12-11
This means that the output of the gas turbine, the output of the air compressor, and the load of the supercharging boiler are also accelerated by t2-t.
It will be accelerated by l.

As described in detail above, according to the present invention, it is possible to rapidly follow the load of a supercharged boiler, for example, load fluctuations in factory air supply or power generation, and at the same time, it can be made to respond quickly to changes in the load of a supercharging boiler, such as load fluctuations due to the temperature of the gas turbine, and thermal stress. There is no problem and the effect is great.

[Brief explanation of drawings]

Figures 1 and 2 show an embodiment of the present invention, with Figure 1 showing the overall configuration of a supercharged boiler, and Figure 2 showing a pressurized boiler that is one of the components of the supercharged boiler. FIG. 3 is a vertical cross-sectional view showing changes over time in gas temperature and flow rate at the gas turbine inlet in comparison with a conventional one. 1... Air suction port, 2... Air compressor, 3... Air conduit, 4... Pressurized boiler, 5... Fuel pipe, 6...Gas conduit, 7
...Gas turbine, 8...Exhaust pipe, 9
...Turbine main shaft, 10...Steam or water inlet, 10', 11, 11'...Steam or water inlet, 13... Wind box, 14... Burner, 15... Combustion chamber,
16...Heat transfer tube, 17...Collecting pipe, 1
8...Nozzle, 19...Collecting pipe, 20
... Nozzle, 21, 22 ... Heat transfer surface,
23... Refractory, 24... Water supply pipe, 2
5...Steam outlet.

Claims (1)

[Claims] 1 Adjust the gas turbine inlet gas temperature and flow rate,
In a method of increasing the load of a supercharged boiler, steam or water is supplied to combustion air or combustion air and the combustion chamber of a pressurized boiler, and the steam or water is heated with combustion gas in the combustion chamber of the pressurized boiler. A method for accelerating a load increase in a supercharged boiler, characterized by supplying the gas to a gas turbine at a specified gas temperature and flow rate.