Material drying system utilizing flue gas waste heat of power plant

Abstract

The utility model discloses a material drying system utilizing flue gas waste heat of a power plant. The material drying system comprises a boiler, a boiler tail flue, a denitration device, an air preheater, a dust remover, an induced draft fan, a desulfurizing tower and a chimney which are communicated in sequence. A bypass flue is arranged on the main flue between the denitration device and the air preheater, a material drying barrel, a dry waste dust remover and a dry waste induced draft fan are sequentially arranged on the bypass flue, and an air outlet of the dry waste induced draft fan is communicated with the main flue behind the dust remover and in front of the induced draft fan through a pipeline. The flue gas waste heat of the power plant is suitable for a newly-built material drying device, the flue gas of the power plant is used as a drying heat source, the system structure is simple, water-containing materials are dried while the flue gas waste heat is recycled, and the fuel utilization efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy conservation and emission reduction in thermal power plants, in particular to a material drying system utilizing waste heat from flue gas in power plants. Background Art

[0002] During the operation of a thermal power plant, the flue gas generated by boiler combustion can reach over 1000°C. The final flue gas temperature is reduced to about 130°C after passing through the heating surfaces at various levels at the rear of the boiler. After denitrification, dust removal, and desulfurization, near-zero emissions are achieved. There are many solid combustibles in conventional production and life, such as sludge, domestic garbage, and high-water-content coal. These materials can be used as fuel, but due to their high water content, they cannot be directly burned and used extensively. Dehydration is generally required, and dehydration requires a high-temperature heat source. The conventional heat source is to burn coal in a newly built coal-fired drying furnace to generate high-temperature flue gas to dry the material. This method has the problems of complex system, low degree of automation, and environmental pollution. Utility Model Content

[0003] The technical problem to be solved by the utility model is that the conventional high-temperature heat source for material dehydration treatment is to burn coal in a newly built coal-fired drying furnace to generate high-temperature flue gas to dry the material. This method has the problems of complex system, low degree of automation and environmental pollution. In order to solve the above problems, a material drying system using waste heat from power plant flue gas is provided.

[0004] The purpose of the utility model is achieved in the following ways:

[0005] A material drying system utilizing waste heat from flue gas in a power plant comprises a boiler 1, a boiler tail flue 2, a denitration device 3, an air preheater 4, a dust collector 5, an induced draft fan 6, a desulfurization tower 7 and a chimney 8 which are connected in sequence; a bypass flue is arranged on the main flue between the denitration device 3 and the air preheater 4, and a material drying cylinder 10, a drying waste dust collector 11 and a drying waste induced draft fan 12 are arranged in sequence on the bypass flue, and an air outlet of the drying waste induced draft fan 12 is connected to the main flue after the dust collector 5 and before the induced draft fan 6 through a pipeline.

[0006] An adjusting door baffle 13 is installed on the main flue after the denitration device 3 and before the air preheater 4, a hole is opened on the main flue before the adjusting door baffle 13 to lead a bypass flue, and a branch adjusting door baffle 14 is arranged on the bypass flue.

[0007] The drying cylinder 10 is provided with a drop hopper 9 .

[0008] A dry fume shutoff door 15 is provided on the flue after the dry waste induced draft fan 12 and before the induced draft fan 6.

[0009] Beneficial effects of the utility model: the utility model utilizes the waste heat of flue gas from power plants, is suitable for newly-built material drying devices and utilizes the flue gas from power plants as a drying heat source, has a simple system structure, dries water-containing materials while recycling the waste heat from the flue gas, and improves fuel utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the utility model.

[0011] Among them, 1-boiler, 2-boiler tail flue, 3-denitrification device, 4-air preheater, 5-dust collector, 6-induced draft fan, 7-desulfurization tower, 8-chimney, 9-drop hopper, 10-material drying cylinder, 11-drying exhaust gas dust collector, 12-drying exhaust gas induced draft fan, 13-main flue regulating door, 14-drying flue gas regulating door, 15-drying flue gas shut-off door. DETAILED DESCRIPTION

[0012] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0013] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same technical meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0014] like Figure 1 As shown, the present invention provides a material drying system utilizing waste heat from flue gas in a power plant, comprising a boiler 1, a boiler tail flue 2, a denitrification device 3, an air preheater 4, a dust collector 5, an induced draft fan 6, a desulfurization tower 7 and a chimney 8 which are connected in sequence; a bypass flue is arranged on the main flue between the denitrification device 3 and the air preheater 4, and a material drying cylinder 10, a drying waste dust collector 11 and a drying waste induced draft fan 12 are arranged in sequence on the bypass flue, and an air outlet of the drying waste induced draft fan 12 is connected to the main flue after the dust collector 5 and before the induced draft fan 6 through a pipeline.

[0015] An adjusting door baffle 13 is installed on the main flue after the denitration device 3 and before the air preheater 4, a hole is opened on the main flue before the adjusting door baffle 13 to lead a bypass flue, and a branch adjusting door baffle 14 is arranged on the bypass flue.

[0016] The drying cylinder 10 is provided with a drop hopper 9 .

[0017] A dry fume shutoff door 15 is provided on the flue after the dry waste induced draft fan 12 and before the induced draft fan 6.

[0018] The working principle of the utility model is as follows: an adjusting door damper 13 is installed on the main flue after the denitrification device 3 and before the air preheater 4, a hole is opened on the main flue before the adjusting door damper, and part of the flue gas is led to the bypass flue, and an adjusting door damper 14 is also added to the bypass flue. After the dry flue gas passes through the material drying cylinder 10, some impurities such as material powder or material volatiles will be carried in the dry flue gas, which is called dry exhaust gas, and the flue gas temperature is reduced to below 150°C. A dry exhaust gas dust collector 11 is installed to remove solid impurities in the dry exhaust gas, and the dust concentration of the outlet dry exhaust gas is lower than 10mg / Nm3. A dry exhaust gas induced draft fan 12 is set after the dry dust collector to overcome the resistance of the dry flue gas. The air volume and pressure head parameters of the dry exhaust gas induced draft fan need to be specifically calculated according to the dry exhaust gas flue layout. The dry exhaust gas after the dry exhaust induced draft fan 12 is connected to the original main flue through the flue, and the access point is selected between the original dust collector 5 and the induced draft fan 6. Because the dry exhaust gas has passed through the denitrification and dust removal devices before, the NOx and dust concentrations in the exhaust gas are up to standard, but the SO2 concentration does not meet the environmental protection requirements, so the dry exhaust gas needs to be mixed with the main flue gas and enter the induced draft fan 6 for further pressure increase and then enter the desulfurization tower 7 for desulfurization treatment, and finally discharged through the chimney 8 to meet the standards.

[0019] The flue gas emitted by the power plant boiler contains NOx, SO2, dust, etc., which need to go through denitrification, dust removal and desulfurization before being discharged through the chimney. The corresponding flue gas temperature also drops from about 1000°C at the furnace outlet to about 50°C at the desulfurization outlet.

[0020] The flue gas temperature in the flue after the denitrification device 3 and before the air preheater 4 is 300-400℃, and the NOx concentration meets the emission requirements. Part of the flue gas is led from this position to the material drying cylinder, and the material falls into the cylinder from the top of the cylinder and is sent from one end of the cylinder to the other end of the cylinder. After the flue gas dries the material, the dry exhaust gas has a low flue gas temperature, and the dust is removed by the dust collector. The dust content of the dry exhaust gas is less than 10mg / Nm3, and then the waste gas is pressurized by the newly built dry exhaust gas induced draft fan and connected to the inlet of the main engine induced draft fan to return to the main flue gas system for discharge after desulfurization.

[0021] The utility model utilizes the waste heat of flue gas from power plants and is suitable for newly-built material drying devices and utilizes the flue gas from power plants as a drying heat source. The system has a simple structure and dries the water-containing material while recycling the waste heat of the flue gas, thereby improving fuel utilization efficiency.

[0022] The above is only a preferred embodiment of the present invention. It should be pointed out that, for those skilled in the art, several changes and improvements can be made without departing from the overall concept of the present invention, and these should also be regarded as the protection scope of the present invention.

Claims

1. A material drying system utilizing waste heat from flue gas of a power plant, comprising a boiler (1), a boiler tail flue (2), a denitration device (3), an air preheater (4), a dust collector (5), an induced draft fan (6), a desulfurization tower (7) and a chimney (8) connected in sequence; characterized in that: A bypass flue is provided on the main flue between the denitration device (3) and the air preheater (4), and a material drying cylinder (10), a drying waste dust collector (11) and a drying waste induced draft fan (12) are provided on the bypass flue in sequence, and an air outlet of the drying waste induced draft fan (12) is connected to the main flue after the dust collector (5) and before the induced draft fan (6) through a pipeline.

2. The material drying system utilizing waste heat from power plant flue gas according to claim 1 is characterized in that: An adjusting door damper (13) is installed on the main flue after the denitration device (3) and before the air preheater (4), a hole is opened on the main flue in front of the adjusting door damper (13) to lead a bypass flue, and a branch adjusting door damper (14) is arranged on the bypass flue.

3. The material drying system using waste heat from power plant flue gas according to claim 1 is characterized in that: The drying cylinder (10) is provided with a drop hopper (9).

4. The material drying system using waste heat from power plant flue gas according to claim 1 is characterized in that: A dry smoke shutoff door (15) is provided on the flue after the dry waste induced draft fan (12) and before the induced draft fan (6).

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