DD158556A1 - METHOD FOR CONTROLLING FIXED BED GENERATORS - Google Patents

Abstract

The invention relates to the control of the generator process of fixed-bed generators. The aim of the invention is to set up an operating regime by selecting technological parameters which determine the generator process, which automatically reacts when faults occur and which prevents the generator from being decommissioned. An increase in operating time, an increase in technological safety and an increase in the availability of the generators are the target variables of the process. The essence of the invention is that in certain technological deviations of the generator is sunk to a minimum load, thereby procedurally brought under control and thus need not be taken out of service.

Description

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Title of the invention

Method of controlling pest bed generators

Field of application of the invention

The invention relates to the field of thermal coal upgrading, especially to the pressure gasification of lignite.

Characteristic of the known technical solutions

The known methods for controlling Pestbettgeneratoren and for technological control of Uormalbetriebes refer to the maintenance of the height of the Peuerbettes and to a uniform flow through the bed. For this purpose, various methods have been developed to measure the instantaneous state, for example according to DD-WP C 10 J / 220 481, in order then to be able to drive the Pest bed generator relatively optimally. However, the staff of the plant is psychologically overwhelmed by the abundance of measured values to be recorded and consequently unable to react ·. Blowing operations, which can lead to accidents and accidents, are therefore inevitable in practical operation. Despite these known laugh parts no solutions for monitoring operations on Pestbettgeneratoren have become known.

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In the further penetration of the process of gas generation in Pestbettgeneratoren has been found, however, that not only the above parameters for a relatively optimal process performance are crucial, but further, previously unnoticed parameters and process conditions must be taken into account.

Object of the invention

The aim of the invention is to avoid the performance reductions due to disruptions in the technological process of the Pestbettgeneratorprozesses, or to reduce to a minimum.

Explanation of the essence of the invention

The object of the invention is to provide a control for Pestbettgeneratoren, according to the Palle of technological disturbances on the Pestbettgenerator this must not be taken out of service and thus the production loss remains within reasonable limits.

Analyzes of the operation process of the Pestbettgeneratoren have shown that the majority of technological disturbances in the Schuttungsaufbau and in the flow behavior of these Pestbettgeneratoren can be overcome by a targeted transition to temporary transient operation. Pestbed generators with disturbed operating behavior can thus continue to be operated by changing the flow behavior through a short-term load reduction and, after returning to the llor mallast, again subject to necessary operating conditions.

The load reduction takes place to a well-defined minimum load and that in case of disturbances in the provision of supplies, allowing a flexible response to operating fluctuations in upstream systems possible

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is, in case of deviations of the vapor-to-oxygen ratio of the gasification agent, in case of deviations of the generator pressure, the raw gas temperature, the oxygen content of the raw gas and the differential pressure of the bed.

The introduced load reduction causes an immediate change in the flow behavior and leads to the construction of an improved bed. Subsequently, the 3 ° estbettgenerator can be increased again to its! Tormalleistung.

During the load depression, a step-shift between vapor and oxygen of the gasification agent is so "always" first the oxygen is reduced and then the gasification vapor and the variations in the vapor-to-oxygen ratio of the gasifying agent remain by the choice of the step width (about 100 cm 0 ₂ / step) low.

embodiment

The invention will be explained below with reference to an embodiment, this embodiment relates to the control of a Pestbettgenerators means of a microcomputer. The gasification agent supply to the Pestbettgeneratoren carried out by means of Vergasungsmittel- single mixture or by a gasification agent collecting system and the generated lianteldampf is used for flushing safety valves and then discharged into the raw gas To control the fixed bed generator, the following technological parameters are used /

- steam-oxygen ratio

- amount of oxygen

- Gasification vapor pressure

- Raw gas temperature

- generator pressure

- Temperature after washer cooler

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- Oxygen content in the raw gas

- Differential pressure over bed.

The magnitude of the deviation is divided into two stages for each technical parameter, namely in

- slight deviation, pre-alarm ♦

- dangerous deviation, ETotaus alarm.

If the following pre-alarms occur during the operation of a Pestbed Generator, the generator will be at minimum load, that is approx. 1.400 Ένα. Q ₀ / h and high steam

"3 oxygen ratio (about 8.5 kg steam / Um O ₂ ) sunk:

- steam-oxygen ratio "high"

- steam-oxygen ratio "deep"

- Gasification steam pressure "deep" - Raw gas temperature "high"

- Raw gas temperature "low"

- generator pressure "high"

- Oxygen content in the raw gas "high"

- Temperature after wash cooler "high" - differential pressure over bed "high"

- differential pressure over bed "deep"

The sinking itself is carried out in 100 NnrOg steps such that always first the oxygen is reduced and then the gasification vapor. In the depression, a step shift between oxygen and steam is maintained, necessary changes in the vapor-to-oxygen ratio occur in 0.1 kg steam / BOrO ₂ steps, the steam being the variable size. This process causes the generator process determining Anazahl of gasification channels of the bed is changed and the Pestbettgenerator reacts properly again. After setting the normal operating conditions, the power of the generator can be increased again as desired.

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The power increase in 100 Hm oxygen steps is carried out by a microcomputer so that first increased according to the steam-oxygen ratio, the corresponding amount of steam and then oxygen is drawn.

For large deviations from the hormonal operation, d. H. Deviation beyond the pre-alarm until the photo-out alarm is triggered, the generator is automatically shut down. The shutdown of the generator is carried out by automatically shutting off the gas mixture single mixture, in which the generator remains at the raw gas network and only a small amount of purging steam ensures the technological flow direction. Automatic relaxation of the generator takes place in response to the Uotausparameters: oxygen content in the raw gas "high".

As there is a risk of explosion, the generator is disconnected from the raw gas network, the gasification agent supply is shut off and the generator is decompressed. During the relaxation process again purging steam flows. If the power of the generator is to be changed during operation and a pre-alarm responds to this load change, which does not automatically lead to load reduction, the load change is stopped until the normal state is reached again and only then is the load change continued.

Claims (2)

229832 2 invention claim 1 · Method for controlling plague bed generators for the brown coal pressure gasification, in particular for the pail of technological disturbances in the mode of operation, in which the supply of the gasification 16O by means of a single gas mixture mixture each. Generator or by means of a gasification agent collecting system and the jacket steam is discharged into the raw gas system, characterized in that a load depression is briefly introduced to a defined minimum load, which is characterized by a still acceptable process, ^j and a predetermined steam-oxygen ratio is set, that further the entire load drop for safety reasons via a step-shift in the steam-oxygen ratio between steam and oxygen is controlled by the fact that during this load reduction of the oxygen is always sunk in front of the steam and that restored after the achieved change in the flow behavior of the Uormalbetrieb and, during the load increase, the step shift between steam and oxygen is exactly the opposite. 2. The method according to item 1, characterized in that load changes are automatically stopped at different technological conditions and continued after setting the normal conditions.