Ignition stable combustion pulverized coal burner

Abstract

The utility model provides an ignition stable combustion pulverized coal burner, which belongs to the technical field of thermal power generation and comprises a heating component, a pre-combustion component and a flame extension tube. The heating assembly comprises a heating pipe, a heating pipe heat preservation layer, a copper pipe and a heating pipe shell. The pre-combustion assembly comprises a pre-combustion chamber, a secondary air inlet pipe, a secondary air cyclone, a pre-combustion chamber fire-resistant layer and a pre-combustion chamber heat preservation layer. According to the ignition stable combustion pulverized coal burner, ignition starting and stable combustion of pulverized coal fuel under the condition of a cold furnace can be achieved, fuel oil, fuel gas or electric energy does not need to be used as auxiliary energy in the operation process, a fuel oil burner and a plasma ignition device can be completely replaced, the ultralow-load stable combustion and flexibility adjusting functions of a power plant boiler can be achieved, and the service life of the power plant boiler is prolonged. And fuel oil does not need to be used as fuel in a thermal power plant.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of thermal power generation, and specifically discloses a coal powder burner for ignition and stable combustion. BACKGROUND

[0002] At present, the burners or auxiliary systems for ignition and stable combustion in the thermal power generation industry generally use fuel oil as fuel, such as the fuel oil burner device and boiler disclosed in CN201822194419.1. However, the use of fuel oil burners has the problems of incomplete combustion in the starting stage, inability to use flue gas treatment environmental protection equipment, and tail gas emission exceeding the standard; in the ignition and stable combustion stage, the fuel oil consumption is huge, and the high price of fuel oil leads to high operation cost.

[0003] The coal powder boiler plasma ignition and stable combustion technology can directly ignite coal powder to replace fuel oil, and is safe, economical and reliable in use. However, the plasma technology has certain limitations when used for ignition, especially for low volatile matter coal, and the ignition ability is not ideal; when used for stable combustion, continuous consumption of electric energy is required during operation, which is poor in economy; in addition, the cathode material of the plasma ignition device has a short service life and needs to be frequently replaced, which seriously affects the operation. CONTENT OF THE UTILITY MODEL

[0004] The utility model provides a kind of coal powder burner for ignition and stable combustion, use coal powder as fuel, and existing fuel in power plant is identical, can completely replace fuel oil burner and plasma ignition device, can realize power plant boiler ultra-low load stable combustion and flexibility regulation function, make thermal power plant not again use fuel oil as fuel.

[0005] The coal powder burner for ignition and stable combustion provided by the utility model, including heating assembly, pre-combustion assembly and flame extension pipe;Heating assembly includes heating pipe, heating pipe heat preservation layer, copper pipe and heating pipe shell;Heating pipe is externally installed with connecting flange II, connecting flange II divides heating pipe into first section and second section;Heating pipe heat preservation layer is wrapped outside the first section of heating pipe;Copper pipe is wound outside heating pipe heat preservation layer, for generating alternating electromagnetic field by electrification;Heating pipe shell is wrapped outside copper pipe;Pre-combustion assembly includes pre-combustion chamber, secondary air inlet pipe, secondary air cyclone, pre-combustion chamber refractory layer and pre-combustion chamber heat preservation layer;Pre-combustion chamber heat preservation layer is laid in pre-combustion chamber;Pre-combustion chamber refractory layer is laid in pre-combustion chamber heat preservation layer;Secondary air inlet pipe passes through pre-combustion chamber, pre-combustion chamber heat preservation layer and pre-combustion chamber refractory layer;Secondary air cyclone is located in pre-combustion chamber refractory layer;The second section of heating pipe is inserted from the first end of pre-combustion chamber refractory layer, connecting flange II is connected with the first end of pre-combustion chamber, secondary air cyclone is sleeved outside the second section of heating pipe, connecting flange II, the second section of heating pipe, pre-combustion chamber refractory layer and secondary air cyclone are enclosed into secondary air passage, and secondary air passage is communicated with secondary air inlet pipe;The first end of flame extension pipe is connected with the second end of pre-combustion chamber refractory layer.

[0006] The ignition and stable combustion pulverized coal burner has a plurality of groups of turbulence components arranged along the axial direction in the heating pipe, each group of turbulence components comprising a plurality of turbulence blocks distributed along the circumferential direction of the heating pipe, and the adjacent two groups of turbulence components are arranged in a staggered manner.

[0007] The ignition and stable combustion pulverized coal burner has a plurality of groups of turbulence components arranged along the axial direction in the heating pipe, each group of turbulence components comprising a plurality of turbulence blocks distributed along the circumferential direction of the heating pipe, and the adjacent two groups of turbulence components are arranged in a staggered manner.

[0008] The ignition and stable combustion pulverized coal burner has a plurality of groups of turbulence components arranged along the axial direction in the heating pipe, each group of turbulence components comprising a plurality of turbulence blocks distributed along the circumferential direction of the heating pipe, and the adjacent two groups of turbulence components are arranged in a staggered manner.

[0009] The ignition and stable combustion pulverized coal burner has a plurality of groups of turbulence components arranged along the axial direction in the heating pipe, each group of turbulence components comprising a plurality of turbulence blocks distributed along the circumferential direction of the heating pipe, and the adjacent two groups of turbulence components are arranged in a staggered manner.

[0010] The ignition and stable combustion pulverized coal burner has a plurality of groups of turbulence components arranged along the axial direction in the heating pipe, each group of turbulence components comprising a plurality of turbulence blocks distributed along the circumferential direction of the heating pipe, and the adjacent two groups of turbulence components are arranged in a staggered manner.

[0011] The ignition and stable combustion pulverized coal burner has a plurality of groups of turbulence components arranged along the axial direction in the heating pipe, each group of turbulence components comprising a plurality of turbulence blocks distributed along the circumferential direction of the heating pipe, and the adjacent two groups of turbulence components are arranged in a staggered manner.

[0012] The ignition and stable combustion pulverized coal burner has a plurality of groups of turbulence components arranged along the axial direction in the heating pipe, each group of turbulence components comprising a plurality of turbulence blocks distributed along the circumferential direction of the heating pipe, and the adjacent two groups of turbulence components are arranged in a staggered manner.

[0013] The ignition and stable combustion pulverized coal burner has a plurality of groups of turbulence components arranged along the axial direction in the heating pipe, each group of turbulence components comprising a plurality of turbulence blocks distributed along the circumferential direction of the heating pipe, and the adjacent two groups of turbulence components are arranged in a staggered manner.

[0014] The ignition and stable combustion pulverized coal burner further comprises a connecting flange V; a connecting flange I is installed outside the first end of the heating pipe; a connecting flange III is installed outside the first end of the precombustion chamber, and a connecting flange IV is installed outside the second end of the precombustion chamber; the connecting flange II is connected with the connecting flange III; a sealing groove is arranged at the second end of the precombustion chamber refractory layer, and a sealing ring is installed in the sealing groove; the connecting flange V is connected with the connecting flange IV and the main burner back plate, and the first end of the flame extension pipe is pressed on the second end of the precombustion chamber refractory layer and in contact with the sealing ring.

[0015] Compared with the prior art, the utility model has the advantages of the following beneficial effects.

[0016] 1、The ignition and stable combustion pulverized coal burner can realize ignition starting and stable combustion of the pulverized coal fuel under the cold furnace condition, does not need to use fuel oil, fuel gas or electric energy as the auxiliary energy source in operation, can completely replace the fuel oil burner and the plasma ignition device, can realize the ultra-low load stable combustion and the flexibility regulation function of the power plant boiler, and makes the thermal power plant not need to use the fuel oil as the fuel.

[0017] 2、Adopting the secondary air distribution, the primary air distribution takes the rapid ignition of the pulverized coal as the target, the secondary air distribution takes the complete combustion and large heat release of the pulverized coal as the target, the range of the applicable coal is increased, the burner is adjusted flexibly, and the ignition and stable combustion effect is good.

[0018] 3、The heating pipe and the precombustion chamber are separated and adopt different materials, the material requirement is obviously reduced, the reliability is increased, and the manufacturing cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the specific embodiment of the utility model or the technical scheme in the prior art, the drawings needed to be used in the specific embodiment or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are some embodiments of the utility model, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 It is a structure schematic view of the ignition and stable combustion pulverized coal burner.

[0021] Figure 2 It is a sectional view of the heating assembly (the spoiler block is wedge-shaped).

[0022] Figure 3 It is a sectional view of the heating assembly (the spoiler block is hemispherical).

[0023] Figure 4 It is a sectional view of the precombustion assembly.

[0024] In the figure: 1-heating pipe; 2-heating pipe insulation layer; 3-copper pipe; 4-heating pipe shell; 5-connection flange I; 6-connection flange II; 7-turbulence block; 8-dividing cone; 9-fixing ring; 10-precombustion chamber; 11-secondary air inlet pipe; 12-secondary air cyclone; 13-precombustion chamber refractory layer; 14-precombustion chamber insulation layer; 15-connection flange III; 16-connection flange IV; 17-sealing ring; 18-flame extension pipe; 19-connection flange V; 20-main burner back plate. DETAILED DESCRIPTION

[0025] The technical scheme of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0026] The embodiment provides a kind of ignition stable combustion pulverized coal burner, including heating assembly, precombustion component, flame extension pipe 18 and connection flange V 19.

[0027] Heating assembly is used to preheat and ignite the coal powder delivered by primary air, including heating pipe 1, heating pipe insulation layer 2, copper pipe 3 and heating pipe shell 4.

[0028] Heating pipe 1 is the core component of heating assembly, is in the alternating electromagnetic field and is inducted to heat, and directly heats the primary air and coal powder flowing in heating pipe 1, reaches the ignition temperature of coal powder;The first end of heating pipe 1 is externally provided with connection flange I 5;Heating pipe 1 is externally provided with connection flange II 6, and connection flange II 6 divides heating pipe into first section and second section.The inner diameter D1 of heating pipe 1 is related to the flow of primary air and coal powder, and the inner diameter D1 is in the range of 0.2m-0.4m, and the length L1 of first section is in the range of 0.6m-1.0m.The material of heating pipe 1 is heat-resistant steel (310S, 0Cr25Ni20).

[0029] Heating pipe insulation layer 2 is wrapped outside the first section of heating pipe 1, to reduce the heat loss of heating pipe 1;The material of heating pipe insulation layer 2 is aluminum silicate fiber felt.

[0030] Copper pipe 3 is wound outside heating pipe insulation layer 2, for generating alternating electromagnetic field by electrification;Condensate water is passed in copper pipe 3 for cooling.

[0031] Heating pipe shell 4 is wrapped outside copper pipe 3, to protect copper pipe 3 and heating pipe insulation layer 2.

[0032] A plurality of groups of turbulence components are arranged along the axial direction in the heating pipe 1, each group of turbulence components comprising a plurality of turbulence blocks 7 arranged along the circumferential direction of the heating pipe 1, and adjacent groups of turbulence components are arranged in a staggered manner. The turbulence blocks 7 are wedge-shaped or hemispherical. In this embodiment, six groups of turbulence components are arranged, each group comprising four turbulence blocks 7 arranged along the circumferential direction of the inner wall of the heating pipe 1, and the installation angle between each group is rotated by 30° along the circumferential direction of the inner wall of the heating pipe 1.

[0033] A flow distribution cone 8 is arranged in the heating pipe 1, the flow distribution cone 8 being located between the turbulence components and the second end of the heating pipe 1, and the diameter of the flow distribution cone 8 gradually increases from the first end to the second end. A fixing ring 9 is arranged vertically on the second end of the flow distribution cone 8, and the fixing ring 9 is fixed to the inner wall of the heating pipe 1. The material of the flow distribution cone 8 is ceramic or silicon carbide. The flow distribution cone 8 is used to scatter the primary air and the coal powder gas flow sent by the heating pipe 1.

[0034] The pre-combustion assembly comprises a pre-combustion chamber 10, a secondary air inlet pipe 11, a secondary air swirler 12, a pre-combustion chamber refractory layer 13 and a pre-combustion chamber insulation layer 14.

[0035] The ignited coal powder stably combusts in the pre-combustion chamber 10 to form a continuous and stable ignition heat source. A connecting flange III 15 is arranged outside the first end of the pre-combustion chamber 10, and a connecting flange IV 16 is arranged outside the second end of the pre-combustion chamber 10.

[0036] The pre-combustion chamber insulation layer 14 is arranged in the pre-combustion chamber 10, and the material is aluminum silicate fiber felt.

[0037] The pre-combustion chamber refractory layer 13 is arranged in the pre-combustion chamber insulation layer 14, and the material is heavy low cement castable. The pre-combustion chamber refractory layer 13 and the pre-combustion chamber insulation layer 14 are used to reduce the heat loss of the pre-combustion chamber 10. The pre-combustion chamber refractory layer 13 comprises an inlet circular table section, a straight cylinder section and an outlet circular table section. The diameter of the inlet circular table section gradually decreases from the first end to the second end. The diameter of the straight cylinder section is equal to the diameter of the second end of the inlet circular table section and the diameter of the first end of the outlet circular table section. The diameter of the outlet circular table section gradually decreases from the first end to the second end. The inner diameter D2 of the straight cylinder section is related to the coal powder flow, and the value range of the inner diameter D2 is 1.4D1-1.6D1. The length L2 of the pre-combustion chamber 10 is in the range of 0.7m-0.9m. A sealing groove is arranged at the second end of the pre-combustion chamber refractory layer 13, and a sealing ring 17 is arranged in the sealing groove.

[0038] The secondary air inlet pipe 11 penetrates through the pre-combustion chamber 10, the pre-combustion chamber insulation layer 14 and the pre-combustion chamber refractory layer 13.

[0039] The secondary air swirler 12 is located in the straight cylinder section of the pre-combustion chamber refractory layer 13.

[0040] The second section of the heating pipe 1 is inserted from the first end of the precombustion chamber refractory layer 13, connected with the connecting flange III 15 of the precombustion chamber 10, and the secondary air swirler 12 is sleeved outside the second section of the heating pipe 1, the connecting flange II 6, the second section of the heating pipe 1, the precombustion chamber refractory layer 13 and the secondary air swirler 12 are enclosed to form a secondary air passage, and the secondary air passage is communicated with the secondary air inlet pipe 11; the secondary air enters from the secondary air inlet pipe 11, forms a rotational flow after passing through the secondary air swirler 12, is uniformly mixed with the primary air and the pulverized coal in the cavity of the precombustion chamber 10, is fully combusted, and a continuous and stable flame is formed.

[0041] The flame extension pipe 18 is used for making the burning pulverized coal flame pass through the cavity of the main burner or the air duct, and is combined with the pulverized coal gas flow of the main burner at a proper position, and plays a role of ignition and stable combustion. The inner diameter D3 of the flame extension pipe 18 is related to the pulverized coal flow, the value range of D3 is 0.9D1-1.1D1, and the length L3 is not more than 3m. The material of the flame extension pipe 18 is silicon carbide or silicon nitride.

[0042] The connecting flange V 19 is connected with the connecting flange IV 16 and the main burner back plate 20, the first end of the flame extension pipe 18 is pressed on the second end of the precombustion chamber refractory layer 13 and is in contact with the sealing ring 17, so that the sealing contact between the flame extension pipe 18 and the precombustion chamber refractory layer 13 is realized.

[0043] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A pulverized coal burner with ignition and stable combustion, characterized in that, Includes heating components, pre-combustion components, and flame extension tubes; The heating assembly includes a heating tube, a heating tube insulation layer, a copper tube, and a heating tube outer shell; A connecting flange II is installed on the outside of the heating tube, which divides the heating tube into a first section and a second section. The insulation layer of the heating tube is wrapped around the outside of the first section of the heating tube; The copper tube is wound around the insulation layer of the heating tube and is used to generate an alternating electromagnetic field when energized. The heating element shell is covered by the copper tube; The pre-combustion assembly includes a pre-combustion chamber, a secondary air inlet pipe, a secondary air cyclone separator, a pre-combustion chamber refractory layer, and a pre-combustion chamber insulation layer; The insulation layer of the pre-combustion chamber is laid inside the pre-combustion chamber; The refractory layer of the pre-combustion chamber is laid inside the insulation layer of the pre-combustion chamber; The secondary air inlet pipe passes through the pre-combustion chamber, the pre-combustion chamber insulation layer, and the pre-combustion chamber refractory layer; The secondary air cyclone separator is located inside the refractory layer of the pre-combustion chamber; The second section of the heating tube is inserted from the first end of the refractory layer of the pre-combustion chamber, and the connecting flange II is connected to the first end of the pre-combustion chamber. The secondary air cyclone is sleeved on the outside of the second section of the heating tube. The connecting flange II, the second section of the heating tube, the refractory layer of the pre-combustion chamber and the secondary air cyclone form a secondary air channel, which is connected to the secondary air inlet pipe. The first end of the flame extension tube is connected to the second end of the refractory layer of the pre-combustion chamber.

2. The ignition and stable combustion pulverized coal burner according to claim 1, characterized in that, Multiple sets of turbulence-disrupting components are arranged along the axial direction inside the heating tube. Each set of turbulence-disrupting components includes multiple turbulence-disrupting blocks evenly distributed along the circumference of the heating tube, and adjacent sets of turbulence-disrupting components are staggered.

3. The ignition and stable combustion pulverized coal burner according to claim 2, characterized in that, The spoiler is wedge-shaped or hemispherical; The adjacent sets of aerodynamic components are offset by 30°.

4. The ignition and stable combustion pulverized coal burner according to claim 2 or 3, characterized in that, A flow divider cone is installed inside the heating tube; The flow divider cone is located between the turbulence assembly and the second end of the heating tube, and the diameter of the flow divider cone gradually increases from the first end to the second end.

5. The ignition and stable combustion pulverized coal burner according to claim 4, characterized in that, A fixing ring is vertically installed at the second end of the flow divider cone, and the fixing ring is fixed to the inner wall of the heating tube; The flow divider cone is made of ceramic or silicon carbide.

6. The ignition and stable combustion pulverized coal burner according to claim 1, characterized in that, The copper pipe contains condensate.

7. The ignition and stable combustion pulverized coal burner according to claim 1, characterized in that, The refractory layer of the pre-combustion chamber includes an inlet frustum section, a straight section, and an outlet frustum section; The diameter of the imported frustum section gradually decreases from the first end to the second end; The diameter of the straight section is equal to the diameter of the second end of the inlet frustum section and the diameter of the first end of the outlet frustum section; The diameter of the outlet frustum section gradually decreases from the first end to the second end; The second end of the heating tube and the secondary air cyclone separator are both located within the straight section.

8. The ignition and stable combustion pulverized coal burner according to claim 7, characterized in that, The inner diameter D1 of the heating tube ranges from 0.2m to 0.4m, and the length L1 of the first section ranges from 0.6m to 1.0m. The inner diameter D2 of the straight section ranges from 1.4D1 to 1.6D1; The length L2 of the pre-combustion chamber ranges from 0.7m to 0.9m; The inner diameter D3 of the flame extension tube ranges from 0.9D1 to 1.1D1, and the length L3 does not exceed 3m.

9. The ignition and stable combustion pulverized coal burner according to claim 1, characterized in that, The heating element is made of heat-resistant steel; The insulation layer of the heating element is made of aluminum silicate fiber felt; The refractory layer of the pre-combustion chamber is made of heavy low-cement castable. The insulation layer of the pre-combustion chamber is made of aluminum silicate fiber felt; The flame extension tube is made of silicon carbide or silicon nitride.

10. The ignition and stable combustion pulverized coal burner according to claim 1, characterized in that, It also includes connecting flange V; A connecting flange I is installed on the first end of the heating element; A connecting flange III is installed at the first end of the pre-combustion chamber, and a connecting flange IV is installed at the second end. Connecting flange II is connected to connecting flange III; A sealing groove is provided at the second end of the fire-resistant layer of the pre-combustion chamber, and a sealing ring is installed in the sealing groove; Connecting flange V is connected to connecting flange IV and the back plate of the main burner, pressing the first end of the flame extension tube against the second end of the refractory layer of the pre-combustion chamber and into contact with the sealing ring.

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