KR100729990B1 - Coal gasfication reactor system using recirculation of coal gas - Google Patents

Abstract

The present invention relates to a coal gasifier system using coal gas recycle.

The present invention provides a coal gasifier system in which a gasification reaction of pulverized coal as a fuel is generated using a coal gasifier to generate a synthesis gas, and the generated synthesis gas is discharged to a subsequent stage. By spraying upward from the lower side in the coalification gasifier, it is characterized in that the gasification reaction by supporting the unburned carbon falling without gasification reaction again.

Therefore, by heating the slack tab to prevent clogging due to slack solidification, the unburned carbon that is not gasified can be gasified again, thereby improving the carbon conversion rate, thereby improving the yield and quality of the synthesis gas, and Since the use of low-cost synthesis gas is produced, it is possible to significantly reduce the maintenance cost.

Gasifier, Coal, Coal Briquette, Slack Tap, Slack, Syngas, Unburned Carbon, Burner

Description

Coal gasifier system using coal gas recirculation {COAL GASFICATION REACTOR SYSTEM USING RECIRCULATION OF COAL GAS}

1 is a schematic view showing a conventional coal gasifier system,

2 is a schematic view showing a coal gasifier system according to the present invention;

Figure 3 is a partial perspective schematic showing the injection nozzle of the syngas burner of the coal gasifier system according to the present invention.

<Description of the symbols for the main parts of the drawings>

110: coal gasifier 112: reaction zone

114: slack tap 116: quencher

118: syngas outlet 120: discharge line

122: cooler 124: dust collector

130: circulation line 132: first pressure flow control valve

132a: bypass line 132b ~ d: manual control valve

134: first high pressure storage container 136: compressor

138: second high pressure storage container 139: second pressure flow control valve

139a: bypass line 139b ~ d: manual control valve

140: differential pressure sensor 150: control unit

160: oxidant supply line 200: methane burner

300: syngas burner 302: burner body

304: injection nozzle 304a: upper shield

304b: lower flame plate 304c: oxidant injection pipe

304d: synthetic gas injection hole

The present invention relates to a coal gasifier system, and more particularly, by compressing and circulating some of the synthesis gas generated by the gasification reaction to be injected upward from the dedicated burner located below the slack tap to heat and block the slack tap. The present invention relates to a coal gasifier system using coal gas recirculation that can prevent the gasification reaction and support the unburned carbon falling to the lower side to allow the gasification reaction again.

In general, coal gasifiers, which are a kind of combustion furnace, are gasified by pulverization of pulverized coal as a fuel, and carbon components in coal are converted into syngas whose main components are carbon monoxide and hydrogen, and the minerals in coal are melted and molten. Will be generated as a slag of.

1 is a schematic view showing a conventional coal gasifier system.

The coal gasifier 110 has a reaction zone 112 in which pulverized coal and an oxidant react in the inner space thereof, and the synthesis gas generated as the gasification reaction proceeds in the reaction zone 112 has an upper end thereof. It is discharged through the formed synthesis gas discharge port 118 is transferred to the rear end process side is used as fuel, etc. At this time, the discharged synthesis gas is a very high temperature, while passing through the cooler 122 installed on the discharge line 120 It is then quenched and then refined while passing through the precipitator 124.

In addition, a slag-tap 114 is formed at the lower side of the reaction region 112 to induce the generated molten slag to flow smoothly to the lower side, and at the lower side of the slack tab 114. A quencher 116 is formed which contains cooling water for cooling and solidifying the slack falling from the side and being immersed.

Therefore, the molten slag generated by the gasification reaction is led to the lower side through the narrow slack tab 114, flows down, and then falls into the quencher 116 to be quench solidified, and then collected in a solidified solid state .

However, the molten slag solidifies in the process of flowing down the portion of the slag tab 114 having a relatively low temperature due to the cooling water at the lower portion, thereby gradually blocking the slag tab 114, thereby preventing normal operation. In order to prevent this in advance, a methane burner 200 using methane gas as a fuel is installed below the slack tab 114 so that the slag is constantly heated around the slack tab 114 during operation. It prevents sticking and solidifying.

However, since the methane burner 200 only plays a role of heating the slack tab 114 by employing a very small injection nozzle, the unburned carbon that is not partially reacted during the gasification reaction and falls to the lower quencher 116 side is By falling as it is and being immersed in the quencher 116, there is a problem that the carbon conversion rate (gasification efficiency) of the fuel is lowered, and as a result, the yield and quality of the synthesis gas are lowered.

In addition, the slack molten methane burner 200 has a problem in that it takes a lot of maintenance costs because it uses a very expensive methane gas as a fuel.

The present invention was devised to solve the above-mentioned problems, by heating the slack tab by circulating a portion of the synthesis gas generated in the coal gasifier under the slack tab to be sprayed upward, as well as not falling. It is an object of the present invention to provide a coal gasifier system capable of supporting carbon back to the reaction zone to allow gasification reaction.

The present invention for achieving the above object, in the coal gasifier system for generating a synthesis gas by the gasification reaction of the pulverized coal as a fuel using a coal gasifier, and discharges the generated synthesis gas to the rear stage side, the discharged Coal gasifier system using a coal gas recirculation characterized in that by circulating some of the synthesis gas to be injected upward from the lower side in the coalification gasifier to support the unburned carbon falling in the gasification reaction to fall again gasification reaction To provide.

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the invention described below with reference to the accompanying drawings by those skilled in the art.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic view showing a coal gasifier system according to the present invention.

Prior to the description, the same reference numerals are given to the same components as in the related art, and detailed description thereof will be omitted.

According to the present invention, by compressing and circulating a part of the synthesis gas generated in the coal gasifier 110, a synthetic gas burner (installed below the slag tab 114 to replace the conventional slag melting methane burner 200 ( By spraying upward from the 300, the slack tab 114 is heated to prevent the slack tab 114 from clogging, and the unburned carbon that cannot be gasified is dropped back to the reaction region 112 for gasification. Allow reaction.

To this end, a circulation line 130 is provided to be branched from the discharge line 120 from which the generated synthesis gas is discharged and connected to the synthesis gas burner 300, and the first pressure flow control is sequentially performed on the circulation line 130. The valve 132, the first high pressure storage container 134, the compressor 136, the second high pressure storage container 138, and the second pressure flow control valve 139 are provided.

The first pressure flow control valve 132 controls the pressure and flow rate of the synthesis gas flowing into the circulation line 130, and a separate bypass line 132a is installed around the bypass line 132a. ) And front and rear ends thereof may be provided with manual control valves 132b to d, respectively.

Accordingly, when the replacement of the first pressure flow control valve 132 occurs due to a failure, the manual control valves 132b and 132c provided on the front and rear ends thereof are closed, and only the manual control valve 132d on the bypass line 132a is closed. Open so that the syngas is supplied through the bypass line (132a).

The first high pressure storage container 134 performs a buffer role of storing the syngas supplied from the first pressure flow control valve 132 side once and supplying it to the next compressor 136 at a constant pressure and flow rate. do.

Compressor 136 may be a dedicated compressor suitable for the characteristics of the synthesis gas, it is supplied by supplying after increasing the pressure by compressing the syngas supplied constant.

The second high pressure storage container 138 performs a buffer role of storing the synthesis gas supplied after being compressed by the compressor 136 and supplying the same at a predetermined pressure and flow rate.

The second pressure flow control valve 139 finally accurately adjusts the pressure and flow rate of the synthesis gas to be supplied to the synthesis gas burner 300 side, and for the same purpose as in the first pressure flow control valve 132 described above. A bypass line 139a is installed around the bypass line, and manual control valves 139b to d may be provided at the bypass line 139a and the front and rear ends thereof.

On the other hand, the syngas burner 300 uses a synthetic gas circulated and supplied as its fuel, and uses an oxidizing agent such as oxygen as a fuel auxiliary agent, and an oxidant is supplied from the outside in addition to the circulation line 130 through which the syngas is circulated. It is also connected to the oxidant supply line 160.

Here, looking at a preferred configuration of the injection nozzle 304 for injecting the syngas and oxidant upward in the syngas burner 300 with reference to the partial perspective schematic view of Figure 3, the upper shield portion of the reverse funnel shape bonded to each other 304a and a funnel-shaped lower retainer plate portion 304b, the center of the upper shield portion 304a and the lower retainer plate portion 304b helps to bond and fix the oxidants therein, and at the upper end thereof. The oxidant injection pipe 304c to be injected is provided in the vertical direction.

Then, the lower flame plate portion 304b is provided to be inserted into the burner body 302 side so that a circular syngas injection port 304d is formed in the gap between the upper end side and the upper end side of the burner body 302.

Here, the upper shield portion 304a has a reverse funnel shape to serve as a protective shield to prevent damage from the molten slack falling from the slack tab 114 side.

The lower flame plate 304b is sprayed through the syngas injection port 304d formed at the upper side after the syngas is moved along the outer surface thereof, and the synthetic gas is pivoted on the outer surface thereof. Guide plates (not shown) may be appropriately laid.

Here, the reason for the syngas to be turned is to be uniformly distributed with the oxidant while being evenly distributed after being injected, in the same manner as the spiral groove for forming the swirl flow on the inner surface of the oxidant injection pipe (304c) Means can be laid appropriately.

On the other hand, according to the present invention, the differential pressure sensor (PDT) 140 for detecting the pressure difference between the upper side and the lower side inside the coal gasifier 110 based on the slack tab 114 is also provided, A control unit 150 for driving control of the first pressure flow control valve 132 (and / or the second pressure flow control valve 139) is also provided according to the result value detected by the differential pressure sensor 140. .

The operation of the coal gasifier system according to the present invention having the above configuration will be described below.

As is well known, first, the inside of the coal gasifier 110 is heated to an appropriate temperature to enable spontaneous gasification reaction, and thereafter, pulverized coal and an oxidant are supplied therein, and the spontaneous gasification reaction proceeds in the reaction region 112. Will be.

Accordingly, the synthesis gas is generated in the coal gasifier 110 is discharged to the discharge line 120 side through the synthesis gas discharge port 118 formed at the upper end, the discharged synthesis gas on the discharge line 120 After being quenched while passing through the installed cooler 122, it is then purified while passing through the dust collector 124 is supplied to the rear stage process side.

At the same time, as the gasification reaction proceeds, molten slack is also generated therein, flows through the slack tab 114, and then falls into the lower quencher 116 to solidify.

Subsequently, some of the synthesis gas discharged to the rear stage is introduced into the circulation line 130 branched from the discharge line 120, and the inflow pressure and flow rate are controlled by the first pressure flow control valve 132. .

Next, the synthesis gas introduced into the circulation line 130 is stored in the first high pressure storage container 134 and then supplied to the next compressor 136 at a predetermined pressure and flow rate to be compressed, and then second high pressure. After being stored in the storage container 138 and also supplied at a constant pressure and flow rate, and finally passed through the second pressure flow control valve 139 is finally adjusted to the appropriate pressure and flow rate for the synthesis gas burner 300 Then, it is supplied to the synthesis gas burner 300 side.

At this time, the oxidant is also supplied to the synthesis gas burner 300 through the external oxidant supply line 160.

Therefore, the syngas burner 300 injects the syngas and the oxidant supplied upward through the injection nozzle 304, and in detail, the syngas is discharged from the lower flame plate portion 304b of the injection nozzle 304. After being moved along the outer surface is injected through the synthesis gas injection port 304d formed in a circular shape on the upper side of the lower flame plate portion 304b, the oxidant is moved through the oxidant injection pipe 304c of the injection nozzle 304 After being sprayed from the upper end.

Here, the injected syngas and the oxidant may be injected to form a swirl flow, respectively, and thus the injected syngas and the oxidant are mixed while moving upward in the coal gasifier 110 and spontaneously according to the internal high temperature situation. It causes a combustion reaction.

Accordingly, the slack tab 114 is heated to prevent the slack from solidifying around the slack tab, and unburned carbon that is not gasified by the injected syngas and the oxidant is dropped in the middle and is supported by the reaction zone. Transfer back to the unit 112 to achieve a gasification reaction.

As a result, the slack tab 114 is prevented from being blocked by the slack, thereby allowing the normal operation continuously, and enabling the gasification of pulverized carbon to improve the carbon conversion rate of the pulverized coal to further improve the production and quality of the syngas. In addition, it is possible to significantly lower the maintenance cost because it uses a synthetic gas produced in-house and cheaper than conventional methane gas.

Meanwhile, according to the present invention, when the slack tab 114 is blocked by the slack under a specific situation, since the pressure between the upper side and the lower side based on the slack tab 114 is different, the differential pressure sensor 140 is provided. Detects the pressure difference and sends the result to the controller 150, the controller 150 further opens the first pressure flow control valve 132 (and / or the second pressure flow control valve 139). It is possible to act to restore the clogged slack tab 114 immediately by increasing the heating temperature by allowing a greater amount of syngas is injected from the syngas burner 300 side.

In addition, the syngas burner 300 according to the present invention should inject syngas at a speed that can adequately support the unburned carbon falling in consideration of the operating conditions inside the coal gasifier 110, for this purpose A control unit (not shown) is provided to control the opening and closing of the second pressure flow control valve 139 according to the operating conditions of the coal gasifier 110 to synthesize the fuel gas at a speed corresponding to the operating conditions at all times. The gas may be configured to be injected.

In the foregoing description, it should be understood that those skilled in the art can make modifications and changes to the present invention without changing the gist of the present invention as merely illustrative of a preferred embodiment of the present invention.

According to the present invention, while preventing the blockage by slack solidification by heating the slack tab, it is possible to gasify the unburned carbon that is not gasified and falls again, thereby improving the carbon conversion rate to improve the production and quality of the synthesis gas. In addition, since low-cost synthetic gas produced by itself is used, the maintenance cost can be greatly reduced.

Claims (5)

In the coal gasifier system for producing a synthesis gas by the gasification reaction of the pulverized coal as a fuel using a coal gasifier, and discharges the generated synthesis gas to the downstream process side, Coal using the coal gas recycle to circulate some of the syngas discharged to be injected upward from the lower side in the coalification gasifier to support the unburned carbon that is not a gasification reaction to fall gasification again Gasifier system. The method of claim 1, Syngas burner which is provided on the coal gasifier side for injecting the syngas to be circulated supply upward; A coal gasifier system using coal gas recirculation comprising a circulation line for circulating and supplying the syngas discharged from the coal gasifier to the syngas burner. The method of claim 2, On the circulation line, At least one pressure control valve for regulating the pressure and flow rate of the circulated syngas, A compressor for increasing the pressure by compressing the circulated syngas; Coal gasifier system using a coal gas recirculation characterized in that the high-pressure storage container for storing and supplying the synthesis gas is provided at each of the front and rear ends of the compressor and supplied at a constant pressure and flow rate. The method of claim 2, The syngas burner, Coal gasifier system using a coal gas recirculation characterized in that the oxidant supplied through the oxidant supply line is connected to the oxidant supply line with the syngas. The method of claim 3, wherein A differential pressure sensor for sensing and transmitting a pressure difference between an upper side and a lower side based on the slack tap provided in the coal gasifier; Coal gasifier system using a coal gas recirculation further comprising a control unit for controlling the opening and closing of the pressure regulating valve in accordance with the detection result of the differential pressure sensor.

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