JPH09221686A - Coal gasification power plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power plant making an air compressor for starting and a gas treating furnace unnecessary and enabling reduction of building area and cost by introducing an inert gas to a gas turbine combustion device, charging from the head or the middle of the combustion device according to calorific value of the inert gas and burning the gas. SOLUTION: The first path for charging an inert gas into a combustion device is provided in the course of body part of a gas turbine combustion device 1 and the second path is provided in the head of the combustion device 1. Further, a fuel nozzle for feeding gas oil which is an auxiliary fuel is provided in the head of the combustion device 1. The charge of an inert gas from the first and second paths and feed of an auxiliary fuel from the combustion nozzle are selected by using calorific vale of the inert gas as an index. Thereby, the objective plant is operated without installing an air compressor and a gas treating facility.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coal gasification power plant in which a gas turbine is operated by using gas generated in a coal gasification furnace.

[0002]

2. Description of the Related Art A conventional device will be described with reference to FIGS. FIG. 3 is a system diagram of this type of coal gasification power generation plant. The starting air compressor 9, the gasification furnace 4, the gas refining equipment 10, the gas processing furnace 11, the combustor 1, the gas turbine 5,
Compressor 6, generator 20, air booster 7, exhaust gas boiler 1
2 and the like.

At the time of startup, after purging the gasification furnace 4 with nitrogen, the startup compressor 9 is started, air is sent to the gasification furnace 4, and the gasification furnace 4 is operated with light oil or the like (not shown). After that, coal is put into the gasification furnace 4 to carry out gasification. At that time, when gas oil or the like is burned, an inert gas containing nitrogen and carbon dioxide steam as main components is generated from the gasification furnace 4, and after the coal is charged, it is changed to carbon dioxide and carbon monoxide increases, and at the same time, the gasification gas The amount of heat generated also increases.

On the other hand, the gas turbine 5 is started by burning light oil or the like, whose supply system is not shown, in the combustor 1, and is operated in a low load state to operate the compressor 6 and the generator 20.
Is driving. Exhaust gas from the gas turbine 5 is guided to the exhaust gas boiler 12 to recover heat.

After that, a part of the air from the compressor 6 of the gas turbine 5 is extracted, and the air is boosted by an air booster 7 and supplied to the gasification furnace 4. The gasification furnace 4 reduces the amount of air from the starting air compressor 9 by that amount, and is finally operated only by the air extracted from the compressor 6 driven by the gas turbine 5.

Further, the combustor 1 gradually reduces the fuel such as light oil and introduces the coal gasification gas correspondingly. Finally, the supply of fuel such as light oil is stopped and only the coal gasification gas is burned to operate the gas turbine 5.

At the time of stop, the flow rate of air drawn from the compressor 6 driven by the gas turbine 5 is reduced. As a result, the supply amount of the coal gasification gas is reduced, but fuel such as light oil is added by that amount and the operation of the gas turbine 5 is maintained. Eventually, the minimum amount of air necessary for the operation of the gasification furnace 4 is extracted from the compressor 6 driven by the gas turbine 5, and the gas turbine 5 itself is operated by burning only light oil or the like. .

In such a series of operations, at the time of starting the gasifier, immediately after the coal is charged, or when the gasifier is stopped, the gas emitted from the gasifier 4 is a burnt gas or has an extremely high calorific value. Since it is a very low gas (a coal gasification gas including these gases is generically referred to as an inert gas in this specification), it cannot be used for operating the gas turbine 5.

However, even though the gas has a low calorific value, it cannot be exposed to the atmosphere as it is. Therefore, the gas processing furnace 11 is burned with light oil. As shown in FIG. 4, the gas treatment equipment ignites a main fuel such as light oil by an ignition device (not shown) and burns this main fuel, and the inert gas is generated around the main fuel supply section or by the main fuel depending on the calorific value. It is injected downstream of the flame to burn combustible components.

[0010]

Although the conventional coal gasification power plant which is in operation has the above-mentioned structure,
The start-up air compressor 9 and the gas treatment facility 11 occupy a considerable part of the construction area and construction cost of the coal gasification power generation plant. In the coal gasification power plant, where the construction area and construction cost are enormous compared to other types of power generation equipment, it is an issue to reduce the facility area and construction cost by simplifying the equipment. .

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the former of the first path and the second path for injecting inert gas into the gas turbine combustor is the same combustor. The latter is provided in the head of the combustor in the middle of the body, and a fuel nozzle for supplying auxiliary combustion fuel such as light oil is provided in the head of the combustor, and the first calorific value of the inert gas is used as a guide. Providing a coal gasification power plant adapted to selectively actuate a second path and a fuel nozzle, directing inert gas to a gas turbine combustor,
According to the calorific value of the inert gas, select the 1st path in the middle of the combustor and the 2nd path of the combustor head to inject the inert gas, and then select the auxiliary fuel such as light oil from the combustor head. The starting air compressor and the gas treatment facility are omitted by supplying and combusting the gas.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. It should be noted that the same parts as those described as the related art previously are designated by the same reference numerals in the drawings, and overlapping description will be omitted.

After the gasification furnace 4 is purged with nitrogen before the plant is started, the gas turbine 5 is started by supplying light oil 8 to the combustor 1 and burning it, and a part of the air from the compressor 6 is extracted. Is further boosted by the air booster 7, and air is sent to the gasification furnace 4. The air is used to burn a fuel such as light oil supplied from a system (not shown) to operate the gasification furnace 4.

After that, coal is put into the gasification furnace 4 to carry out gasification. At that time, an inert gas containing nitrogen, carbon dioxide, and steam as main components is generated from the gasification furnace 4 during combustion of light oil, and after coal is added, carbon monoxide increases and carbon monoxide increases, and at the same time, the calorific value of the inert gas. Will also increase.

These inert gases are introduced into the combustor 1 of the gas turbine 5 through the gas refining equipment 10, and are injected from the head of the combustor or in the middle thereof in accordance with the amount of heat generated by the inert gas and burned. That is, when the calorific value of the inert gas is low and it is difficult to burn the inert gas, the inert gas is injected into the combustor 1 through the first path 1A provided immediately upstream of the bypass valve 3 in the middle of the combustor 1 and burned.

The bypass valve 3 is provided for the purpose of adjusting the flow rate of the air that normally flows into the upstream side of the combustor 1. By opening the valve 3, the head of the combustor 1 is bypassed. It is provided for the purpose of merging air from the middle of the combustor 1.

On the other hand, when the calorific value of the inert gas rises, the gas turbine combustor 1 is supplied with the fuel 8 such as light oil being supplied, with the calorific value calculated by a device (not shown) for analyzing the inert gas component as a guide. The inert gas is injected from the second path 1B including the fuel swirler 2 and the like at the head of the engine and burned. At this time, the flow rate of fuel such as light oil is adjusted by an appropriate control device (not shown) so that the temperature of the outlet of the combustor 1 (the inlet of the first stage vane 13 of the turbine 5) becomes constant.

When the calorific value of the inert gas further rises and starts to burn independently, the supply of fuel such as light oil is stopped and only the inert gas which is a coal gasification gas is burned to operate the gas turbine 5. Becomes

At the time of stopping, the coal charging to the gasification furnace 4 is stopped. As a result, the calorific value of the coal gasification gas is reduced, but the auxiliary combustion fuel such as light oil is injected into the combustor 1 and burned to maintain the operation of the gas turbine 5.

Using the calorific value calculated by the inert gas component analysis as a guide, the gas supply is switched from the middle to the supply from the first path 1A upstream of the bypass valve 3 and finally the minimum required for the operation of the gasification furnace 4. A transition is made to a mode in which a limited amount of air is extracted from the gas turbine 5, and the gas turbine 5 itself is operated by burning only light oil.

As described above, according to this embodiment, the plant can be operated without the need for the starting air compressor and the gas treatment furnace, unlike the conventional one. Then, as a result of operating the gas turbine 5, the generator 20
Is driven to obtain a predetermined amount of electric power, which is a power plant.

The exhaust gas of the gas turbine 5 is introduced into the exhaust gas boiler 12, and the subsequent steps are omitted in the drawing, but the steam generated by the exhaust gas boiler 12 operates the steam turbine to generate electricity separately. It goes without saying that, if done, the combined power generation plant can be completed here together with the generator 20.

Therefore, in this case, the term "coal gasification power generation plant" in this specification may be appropriately read as "coal gasification combined cycle power generation plant".

Although the present invention has been described with reference to the illustrated embodiment, the present invention is not limited to such an embodiment.
It goes without saying that various modifications may be made to the specific structure within the scope of the present invention.

[0025]

As described above, according to the present invention, the inert gas is introduced into the gas turbine combustor, and the starting air compressor and the gas are injected by burning the inert gas from the head of the combustor or in the middle of the combustor according to the calorific value of the inert gas. No processing furnace required,
We were able to obtain a power generation plant that made it possible to reduce the construction area and cost.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a combustor used in a coal gasification power plant according to an embodiment of the present invention.

FIG. 2 is a system diagram of a coal gasification power plant incorporating the combustor of FIG.

FIG. 3 is a system diagram of a conventional coal gasification power generation plant.

FIG. 4 is a schematic diagram of a gas treatment furnace incorporated into that of FIG.

[Explanation of symbols]

 1 Combustor 3 Bypass Valve 4 Gasification Furnace 5 Gas Turbine 6 Compressor 12 Exhaust Gas Boiler 20 Generator 1A 1st Route 1B 2nd Route

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroyuki Nishida, Inventor Hiroyuki Nishihama 1-1-1, Arai-cho, Takasago-shi, Hyogo Mitsubishi Heavy Industries, Ltd. Takasago Research Center (72) Inventor Watao Sato 2-chome, Niihama, Arai-cho, Takasago-shi, Hyogo No. 19 Takahishi Engineering Co., Ltd.

Claims (1)

[Claims] 1. A first path and a second path for injecting inert gas into a gas turbine combustor, the former is provided in the middle of the body of the combustor and the latter is installed at the head of the combustor, and light oil, etc. A fuel nozzle for supplying auxiliary combustion fuel is provided at the head of the combustor, and the first and second paths and the fuel nozzle are selectively operated by using the calorific value of the inert gas as a guide. Characteristic coal gasification power plant.