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Abstract

Content

Introduction

The main problem of operating modern boiler, using solid fuel, such as a black coal is the low quality of the latter. The content of coal dust often reaches 30–40 %, which is too high for many types of boiler plants. Therefore, it is expedient to use a low-temperature fluidized bed fire chamber, which can work even under conditions of high ash content of up to 60 %. In the coal enterprises using this type of boiler plant for the recycling from coal mining or an enrichment [1]. Therefore, the question becomes relevant automation of the technical process, which still not fully disclosed. The reason for this is the uniqueness of each company, and various heat consumers on it, which often leads to solutions that will satisfy only one company, for which developed these solutions.

1. Analysis of boiler plant with low-temperature fluidized bed fire chamber

The low-temperature fluidized bed has been used successfully for burning lean coal. It is intended to create conditions for the existence of кипящего слоя and forced combustion of solid fuel with an ash content not exceeding 60 %and a calorific value of not less than 1800 kcal/kg, with a size of 0-35 mm pieces of coal and fines content of up to 1 mm no more 30 % [2]. In a general view boiler plant with a furnace with low-temperature fluidized bed is shown in Figure 1.

Figure 1 — The boiler plant with a furnace with low-temperature fluidized bed

Figure 1 — The boiler plant with a furnace with low-temperature fluidized bed

The installation, which is the object of study and automation, and is used in the coal company for the needs of heat supply coal mine and needs of modern automation solutions to increase energy efficiency boiler plant and its safety.

2. A critical review of the known technical solutions for the automation of boiler plants with low-temperature fluidized bed fire chamber

Sole system of automation of boiler plants is the automatic control system КОНТУР [4]. The main function of the automatic control system КОНТУР is a secure automated management of technological boiler equipment in accordance with the technical regulations of the enterprise, in order to maintain the necessary technical and economic parameters of the equipment. Structurally boiler automatic control system made in a separate cabinet.

3. Rationale for structure of the mathematical model of thermal processes in low-temperature fluidized bed fire chamber

To accomplish analyzed the theory of combustion of gaseous, liquid and solid fuels involved in the process of firing and transfer to a stationary mode with low-temperature fluidized bed furnace. The estimation of the dynamic properties of boiler plant with a furnace with low-temperature fluidized bed, the reaction of the combustion process on the disturbing effects and dependence of these reactions [6].

Synthesis of a mathematical model of thermal processes in low-temperature fluidized bed furnace to be carried out in MATLAB software package, and therefore, the structure of the mathematical model of the furnace firing in low-temperature fluidized bed furnace presented in a dynamic (Fig. 2). The structure based on a decomposition method [7]. All input and output values change over time.

Figure 2 — Structure of the mathematical model (animation: 7 frames, 5 repetition cycles, 139 KB)

Figure 2 — Structure of the mathematical model
(animation: 7 frames, 5 repetition cycles, 139 KB)

Conclusion

Thus, this structure is a mathematical model of thermal processes in low-temperature fluidized bed furnace taken as the basis for the research towards the development of a system for automatic control of transients in the boiler system with low-temperature fluidized bed fire chamber.

In writing this essay master's qualification work is not completed. Date of final completion — June 2017. Full text of work and materials on a work theme can be received from the author or his supervisor after that date.

References

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