JP2802504B2 - Coal gasifier startup or hot banking system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a coal gasification plant, and to starting or hot banking of a coal gasification furnace suitable for improving plant safety, environmental protection and economy. (Temperature maintenance) system.

[Conventional technology]

In a conventional coal gasifier start-up or hot banking system, a burner was burned by supplying fuel from utilities such as oil and gas, which were separate from coal, and the coal gasifier was heated until coal ignition. Thereafter, a system is provided in which coal is supplied, the coal is ignited, and coal gasification is performed (see Japanese Patent Application Laid-Open No. 58-154797).

In addition, a slag tap burner is installed to facilitate the flow of slag from the lower part of the coal gasifier during operation (see JP-A-60-92391).

That is, as shown in FIG.
Is equipped with a starter burner 36 and a slag tap burner 2, each of which is provided with fuel equipment 34, 35 for the burner.

In a plant such as an integrated gasification combined cycle power plant where load fluctuations such as daily start and shutdown occur severely in a day, burners 6 and 7 are ignited for hot banking in order to shorten the startup time of the gasifier. The system keeps the temperature. However, in these methods, for hot banking and slag tap burners,
This system does not use coal, which should be the original raw material, but uses a large amount of another fuel such as oil or gas.

[Problems to be solved by the invention]

In the conventional coal gasifier start-up or hot banking system, the start-up and hot banking of the coal gasifier use fuels other than coal, such as oil and gas,
There was a problem with poor economy.

SUMMARY OF THE INVENTION An object of the present invention is to provide a coal gasifier having high economic efficiency and high environmental preservation that can operate with little use of utilities such as oil and gas even when the coal gasification operation is not performed during normal operation. It is to provide an activation or hot banking system.

[Means for solving the problem]

In order to achieve the above object, the start-up or hot-banking system of the coal gasifier according to the present invention starts or starts the coal gasifier that performs heating and hot banking before the start of the coal gasifier by burning a burner. In the hot banking system, the generated gas is connected to a burner so that it can be used as a heating source at the time of startup or hot banking.

In the start-up or hot-banking system of the coal gasification furnace in which heating and hot banking before the start of the coal gasification furnace are performed by burning a burner, a circulation line for circulating a part of the generated gas is provided, and the circulation line is provided. The structure connected to the slag tap burner of a coal gasifier may be sufficient.

Further, a configuration in which a starting or tap burner is installed below the slag tap of the coal gasifier may be used.

Further, a configuration in which a compressor is provided in the circulation pipe, and a gas holder and its bypass pipe are provided downstream of the compressor may be used.

Further, a configuration having a pipeline for flowing excess gas during hot banking to the combustion facility may be provided.

[Action]

According to the present invention, the start-up and hot-banking system of the coal gasifier is provided with a circulation pipe for circulating a part of the generated gas and connected to a burner such as a slag tap burner, so that the gas is generated in the burner at startup. Gas is supplied, and the generated gas generated by minimizing the coal supply during hot banking is circulated to the burner. In addition, the flow of slag is promoted.

At start-up (cold start), a part of the generated gas is stored in the gas holder before the previous operation stop, so that the stored generated gas is supplied to the burner and used as fuel. Example] An embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 1, in the start-up and hot-banking system of the coal gasifier 1 in which the heating and hot banking before the start of the coal gasifier 1 are performed by the burner 2, a part of the generated gas is circulated. In this configuration, a pipeline 14 is provided, and the circulation pipeline 14 is connected to the slag tap burner 2 of the coal gasifier 1. Then, a starting or tap burner may be installed below the slag tap of the coal gasifier 1.

Further, the compressor 10 is provided in the circulation line 14, and the gas holder 9 and its bypass line 25 are provided downstream of the compressor 10.
And a pipeline 15 for flowing excess gas during hot banking to a combustion facility, for example, an exhaust heat recovery boiler 18.

In this system, a heat recovery device 11 and a dedusting / desulfurization device 12 are connected to a generated gas line from a coal gasifier 1 to produce a clean gas, and then the gas is generally supplied to a gas turbine 20 via a main gas line 16. Send and generate electricity. Exhaust gas is HR
The heat is recovered by steam by an SG (exhaust heat recovery boiler) 18 and then exhausted from a chimney 19. Steam from HRSG18,
Along with the steam generated in the coal gasifier 1 and the heat recovery unit 11, the steam is sent to a steam turbine 21 via a pipe 22 to generate power. A circulation pipe (recycling line) 14 is installed in the generated gas line 13 to partially bleed the generated gas, pressurized by the compressor 10, and then supplied as fuel to the burner 2 through the recycle valve 8. A surplus gas line 15 is provided in the generated gas line 13, and the surplus gas is circulated to the HRSG 18 via the duct burner 17, and is incinerated to recover heat.

 Next, the operation of the present embodiment will be described.

During a normal coal gasification operation, in order to promote the slag flow down of the coal gasifier 1, a part of the generated gas is extracted by the circulation line 14, the pressure is increased by the compressor 10, and then the oxidizing agent for the burner is burned by the burner 2. Incinerate with oxygen or air. That is, the slag tap burner does not require any fuel other than coal, and can be handled only with coal.

When performing a daily start or a shutdown after normal operation, the coal gasifier 1 has a built-in membrane wall 23 for generating steam, so that the temperature in the coal gasifier 1 rapidly decreases and hot banking is difficult. become.
Then, the minimum amount of coal 3 is fed into the coal gasifier 1 together with the coal carrier gas 5 and the gasifying agent 6 via the lock hopper 4 to gasify the coal, and the generated gas is supplied to the burner 2 through the circulation line 14. Also, it is used for maintaining hot banking and for heating the slag tap section. However, in this case, it is assumed that the burner 2 does not burn completely but burns under the theoretical combustion condition or less. In complete combustion or in the state of excess air (oxygen), the combustion is performed under theoretical combustion conditions in order to further combust with the coal gasification gas in the upper part and reduce calorie generated gas. Therefore, gas increases in the product gas system due to the combustion of coal gasification gas and burner 2,
A part of surplus gas is removed from the pipe 15, burned by the duct burner 17, heat is recovered by the HRSG 18, and hot banking of the HRSG 18 is maintained. By maintaining the temperatures of the coal gasifier 1, the heat recovery unit 11, and the dust removal / desulfurization unit 12 of the produced gas system by such means, it is possible to remove dust and desulfurize the produced gas, and to reduce the environment of exhaust gas. Maintenance can be maintained. Further, since all the steam systems are maintained in the hot banking state, a short-time restart (starting of the gas turbine) is also possible.

At the time of startup (at the time of a cold start), the generated gas is stored in the gas holder 9 before the previous operation is stopped, and the generated gas is supplied to the burner 2 from the gas holder 9 at the time of startup, and burned.
It is something that starts.

According to the present embodiment, gasification operation and start-up can be performed using only coal without using fuel other than coal, and the temperature can be maintained during hot banking, and the daily start and shutdown can be performed in a short time. Become.

As another embodiment of the present invention, coal gasification product gas,
The plant used for fuel or chemical feedstock has no steam turbine equipment after the gas turbine shown in Fig. 1, and it is assumed that surplus gas is incinerated in a flare stack normally used instead of a duct burner, Roads are provided.

〔The invention's effect〕

According to the start-up or hot-banking system of the coal gasifier of the present invention, since fuel such as oil and gas other than coal is hardly used, no equipment is required, utility costs are reduced, and economy is improved. In addition, hot banking is sufficient for both the gasification system and the steam system, so that startup can be performed in a short time. The gasification system also hot banking state due to the gasification atmosphere (reducing atmosphere), the performance of the desulfurization apparatus (desulfurization H ₂ S) is also sufficiently exhibited,
Environmental preservation is also ensured.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional technique. 1 ... coal gasifier, 2 ... burner, (slag tap burner) 9 ... gas holder, 10 ... compressor, 14 ... circulation line, 15 ... line.

Claims (5)

(57) [Claims] In a starting or hot banking system for a coal gasifier in which heating and hot banking before starting of the coal gasifier are performed by burning a burner, generated gas is used as a heating source at the time of startup or hot banking. A coal gasifier startup or hot banking system operably connected to said burner. 2. A starter or hot banking system for a coal gasifier in which heating and hot banking before starting the coal gasifier by burning a burner are provided with a circulation line for circulating a part of the product gas. A startup or hot banking system for a coal gasifier, wherein the circulation line is connected to a slag tap burner of the coal gasifier. 3. A starting or hot banking system for a coal gasifier according to claim 2, wherein a starting or tap burner is installed below the slag tap of the coal gasifier. 4. The starting or hot banking system for a coal gasifier according to claim 2, wherein a compressor is provided in the circulation line, and a gas holder and a bypass line are provided downstream of the compressor. 5. The starting or hot banking system for a coal gasifier according to claim 2, further comprising a pipeline for flowing surplus gas during hot banking to the combustion equipment.