DD282142A7 - PROCESS FOR LOAD DISTRIBUTION IN A GAS GENERATION SYSTEM - Google Patents

Abstract

The invention relates to a method for load distribution in a gas generating plant. It relates to the field of fixed bed pressure gasification of coal. The aim of the invention is to improve the efficiency of gas production in a fixed bed pressure gasification plant. The task is to find a suitable load distribution. According to the invention, the object is achieved by the load distribution for the individual gas generators as a function of economic criteria such as CO2 content, oxygen consumption and ash discharge after each ash removal process and in particular the ash discharge behavior and CO2 content in the raw gas ; Brown coal; Oxygen stress; CO2 concentration; raw gas; ash discharge}

Description

Field of application of the invention

The invention relates to the field of fixed bed pressure gasification of brown coal, in particular Niederlausitzer lignite.

Characteristic of the known state of the art

In a modern gas generation plant, the individual fixed-bed pressure carburetors are regulated in a generator-specific manner on account of the action of a large number of influencing variables on the combustion, gasification and heat exchange processes.

Depending on the requested total gas output and the supply of gasification agent and gasification agent, the total load on the available gas generators is approximately evenly distributed.

In DD-WP 241f 08 it is proposed to carry out a state analysis for a specific time range for each individual generator for the safe operation of generator quadrature, assuming the performance for a certain time range and to perform an optimal power distribution within the group of four according to the determined power limit, which in particular the required optimum utilization of the generator group of four at the same time as compliance with the applicable safety requirements.

Although the proposed method allows to carry out the load distribution so that a gas generating plant can be safely operated with maximum time utilization at the upper power limit, but has the distinct disadvantage that the economic production of gas is disregarded.

However, for coal upgrading and especially for fixed-bed pressure gasification, the effectiveness or efficiency of the process is the decisive criterion.

Object of the invention

The aim of the invention is to improve the economics of generating gas in a fixed bed pressure gasification plant.

Explanation of the essence of the invention

The invention has for its object to find a load distribution for a fixed-bed pressure gasification plant, with the aid of the economy of gas production can be improved.

According to the invention the object is achieved in that as a criterion for the load distribution, the combination of ash discharge behavior and CO ₂ content in the raw gas is used. In this way, for the first time at the same time the efficiency of the gasification reaction and the Arteil of the carbon of the gasification coal used, which is chemically reacted in Festbettdruckvergaser be used as a control variable.

To carry out the process, the detection of the CGy content, the use of coal and the ash discharge takes place in real-time operation. According to the invention, the process is carried out at the fixed bed pressure gasification of Niederlausitzer lignites having an ash content of 8-11% and a water content of 18-26%, in such a way that event-related after each deashing process those gas generants having a CGy content of less than 33.5 %, are operated with an oxygen load of greater than 350m ³ iN / hm ² generator cross section and those with greater than 33.5% CGyGehalt in the raw gas to less than 200 m ³ iN / hm ² generator cross section are used, with a difference to the total load requested by those with greater than 33.5% CGy content in the raw gas, in which equal / greater than 60% of the ash introduced with the coal is discharged via the rotary grate, is generated in equal parts.

In addition, those gas generators that have a COy content of more than 34% in the raw gas over an operating time of 24 hours and an ash discharge will be present. less than 60% above the rotary grate, put out of service. It was found that at unfavorable

Flow conditions in the fixed bed pressure carburetor, which cause incomplete conversion reactions, the CO ₂ content increases to greater than 34% and the proportion of ash discharged through the rotary grate decreases. The ash which has not been removed via the rotary grate is transported with the raw gas and leads proportionally to about 30% carbon from the reactor, which can not be converted into gas. This can be tracked by measuring the oxygen consumption, based on the feed coal, metrologically.

embodiment

The invention will be explained in more detail below by means of an embodiment.

The example relates to a fixed bed pressure gasification plant with 10 i ^T estbeddruckvergasern, which have an inner diameter of 3.6 m and a total available amount of oxygen of 30000m ³ iN / h. The 10 gas generators are in operation with 3 000 m ³ iNO ₂ / h each. As Vergasungsstc'f lignite briquettes are used. For each gas generator, a determination of the ratio of total to total ash is made with each ash removal operation, this ratio being compared with the trend of the last eight ash removal operations. At the same time, the actual value of COy content was recorded and compared with the trend of the last 24 hours

 The following conditions result for the 10 gas generators:

gas generator GyBelastung CO ₂ content CO ₂ content discharged ash 08 ash removal m ³ iN / h Actual value % 24-h value Actual value operations 75 1 30C0 33 33 70 76 2 3000 32.5 33 65 75 3 3,000 32.5 33 70 65 4 1.6 3000 34 33 65 55 5 0 3 00C 3t 34.5 58 55 6 0 2,000 34 34 58 65 7 1.6 3,000 33.8 33.5 70 80 8th 3000 33 33 80 80 9 3,000 33 33 80 75 10 3000 33 33 75

According to the invention, the load distribution on the basis of this state analysis is as follows: Gas generator 1 2 3 4 5 6 7

O ₂ load m ³ iN / h

4000

4,000

4,000

3,000

4,000

4,000

4,000

Gas generators 5 and 6 are put out of operation. After discharging a portion of the bed of gas generators they can be put into operation again.

Claims (2)

1. A method for load distribution in a gas generating plant, in particular a consisting of several gas generators plant for fixed bed pressure gasification of Niederlausitzer brown coal with an ash content of 8-11% and a Wasserrjehalt 18-26%, the CO ₂ content in the raw gas, the coal and the ash discharge are detected in real-time operation, characterized in that event-related after each ash removal the dieienigen gas generators, which have a CO ₂ content in the raw gas of equal / less than 33.5% with an oxygen load greater than 350m ³ iN / hm ² generator cross section and operated those with greater than 33.5% CGy content in the raw gas to an oxygen load of less than 200m ³ iN / hm ² generator cross section are sunk, with a difference to the total load requested to the gas generators with a CO ₂ content of greater than 33.5% is divided equal to or greater than 60% of the ash introduced with the coal over the rotary grate be gene. 2. The method according to claim 1, characterized in that those gas generators that have over 24h operating time a CO ₂ content in the raw gas of greater than 34% and an ash discharge of less than 60% on the rotary grate, are put out of service.