Supercritical unit boiler soot blowing steam source device

Abstract

The present application relates to the technical field of air preheater, in particular to a supercritical unit boiler soot blowing steam source device. The present application separately leads a soot blowing pipeline from a boiler body soot blowing steam source adjusting door to separate the air preheater soot blowing device from the boiler body soot blowing device, which can ensure the steam supply when the air preheater continuously blows soot, and can solve the problems of unstable steam supply pressure of auxiliary steam to the air preheater and long-term pressure on the boiler body soot blowing device lifting valve.

Description

Technical Field

[0001] This invention relates to the field of air preheater technology, and in particular to a soot blowing steam source device for a supercritical boiler unit. Background Technology

[0002] The air preheater soot blowing steam source consists of two parts: one is the auxiliary steam source, and the other is the boiler body soot blowing steam source. When the coal type varies significantly in ash content, the air preheater needs to continuously blow soot to prevent blockage. Because the auxiliary steam pressure changes in sync with the unit load, sometimes the auxiliary steam supply pressure is less than 1 MPa, which cannot meet the air preheater soot blowing steam source pressure requirements. When the air preheater uses the boiler body soot blowing steam source, this source connects to all soot blowers in the boiler body. During air preheater soot blowing, the soot blowers in other boiler body soot blowers are under pressure. If the soot blower soot blower riser valves are not airtight and leak internally, they can scour and damage the boiler body's heating surfaces, potentially causing surface bursts and unit shutdown.

[0003] The existing technology has the following problems:

[0004] 1. Due to changes in the type of coal burned in the boiler, when the ash content of the coal changes significantly, in order to prevent the air preheater from becoming clogged, the pressure difference between the inlet and outlet of the air preheater increases, and the air preheater needs to be continuously blown with soot.

[0005] 2. The air preheater soot blowing steam source is provided by two parts: one is the auxiliary steam source for air preheater soot blowing, and the other is the boiler body soot blowing steam source. Since the auxiliary steam pressure is linked to the unit load change, the auxiliary steam supply pressure is sometimes less than 1MPa at low load, which cannot meet the soot blowing conditions. Therefore, the air preheater continuous soot blowing steam source can only be taken from the boiler body soot blowing steam source.

[0006] 3. When the air preheater soot blowing steam source is provided by the boiler body soot blowing steam source, since the air preheater soot blower, boiler body soot blower, furnace long soot blower, and economizer soot blower belong to the same system, when the air preheater is blowing soot, the riser valves of other boiler body soot blowers are also under pressure. If these soot blowers leak internally in their riser valves when they are not blowing soot, the leaking steam will wash away and damage the heating surface, threatening the safe operation of the heating surface. Summary of the Invention

[0007] To address the above problems, the present invention provides a steam source device for soot blowing in supercritical boiler units.

[0008] This invention provides a soot blowing steam source device for a supercritical boiler, comprising:

[0009] The first pipe from the boiler body to the furnace soot blower is equipped with a soot blowing safety valve 4.

[0010] The first pipeline soot blowing safety valve 4 is connected to the furnace soot blower by a second pipeline leading to the denitrification soot blower. The second pipeline is equipped with a denitrification check valve.

[0011] A third pipe leading to the air preheater is connected between the second pipeline denitrification check valve and the denitrification soot blower.

[0012] A fourth pipe leading to the air preheater is installed between the connection point of the first and second pipes and the soot blowing safety valve 4.

[0013] Furthermore, a new active electric door 5 is installed on the first pipe between the connection point of the first pipe and the connection point of the second pipe and the connection point of the first pipe and the fourth pipe.

[0014] Furthermore, between the connection point of the first and fourth pipes and the connection point of the fourth and third pipes, a new air preheater soot blowing steam source electric door 7 is installed on the fourth pipe.

[0015] Furthermore, between the connection point of the first and fourth pipelines and the connection point of the fourth and third pipelines, a new manual valve 6 for the air preheater soot blowing steam source is also installed on the fourth pipeline.

[0016] Furthermore, the device also includes a fifth pipeline from the auxiliary steam to the air preheater.

[0017] Furthermore, the fifth pipeline is equipped with an auxiliary steam to air preheater soot blowing isolation door 8 and an auxiliary steam to air preheater soot blowing non-return door 9.

[0018] Furthermore, a soot blowing steam source regulating valve 3 is installed between the boiler body and the soot blowing safety valve 4 on the first pipeline.

[0019] Furthermore, a manual soot blowing valve 1 and an electric soot blowing valve 2 are installed between the boiler body and the soot blowing steam source regulating valve 3 on the first pipeline.

[0020] Furthermore, a denitrification and soot blowing isolation door 11 is installed at the end of the second pipeline near the denitrification soot blower.

[0021] Furthermore, an air preheater soot blowing isolation door 12 is installed at the end of the fourth pipeline near the air preheater.

[0022] This invention has at least the following beneficial effects:

[0023] This invention provides a separate soot blowing pipeline from the boiler body soot blowing steam source regulating valve to supply soot blowing to the air preheater, which is separate from the boiler body soot blowing. This not only ensures the steam supply during continuous soot blowing in the air preheater, but also solves the problems of unstable auxiliary steam supply pressure to the air preheater and long-term pressure in front of the boiler body soot blowing lifting valve.

[0024] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the soot blowing steam source device according to an embodiment of the present invention.

[0027] In the attached diagram: 1 - Manual door for soot blowing steam source; 2 - Electric door for soot blowing steam source; 3 - Regulating door for soot blowing steam source; 4 - Soot blowing safety valve; 5 - Newly added active electric door; 6 - Newly added manual door for air preheater soot blowing steam source; 7 - Newly added electric door for air preheater soot blowing steam source; 8 - Auxiliary steam to air preheater soot blowing isolation door; 9 - Auxiliary steam to air preheater soot blowing non-return door; 10 - De-pin non-return door; 11 - De-pin soot blowing isolation door; 12 - Air preheater soot blowing isolation door. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] In the existing technology, when the air preheater soot blowing steam source is provided by the boiler body soot blowing steam source, since the air preheater soot blower, boiler body soot blower, furnace long soot blower, and economizer soot blower belong to the same system, when the air preheater is blowing soot, the riser valves of other boiler body soot blowers are also under pressure. If these soot blowers leak internally in their riser valves when they are not blowing soot, the leaking steam will wash away and damage the heating surface, threatening the safe operation of the heating surface.

[0030] This invention provides a separate soot blowing pipeline from the boiler body soot blowing steam source regulating valve 3 to supply soot blowing to the air preheater soot blower, which is separate from the boiler body soot blower. This not only ensures the steam supply during continuous soot blowing in the air preheater, but also solves the problems of unstable auxiliary steam supply pressure to the air preheater and long-term pressure in front of the boiler body soot blower lifting valve.

[0031] like Figure 1 As shown, the present invention provides a soot blowing steam source device for a supercritical unit boiler, comprising:

[0032] The first pipe from the boiler body to the furnace soot blower is equipped with a soot blowing safety valve 4.

[0033] The first pipeline soot blowing safety valve 4 is connected to the furnace soot blower by a second pipeline leading to the denitrification soot blower. The second pipeline is equipped with a denitrification check valve.

[0034] A third pipe leading to the air preheater is connected between the second pipeline denitrification check valve and the denitrification soot blower.

[0035] A fourth pipe leading to the air preheater is installed between the connection point of the first and second pipes and the soot blowing safety valve 4.

[0036] In one embodiment, a new active electric door 5 is provided on the first pipe between the connection point of the first pipe and the second pipe and the connection point of the first pipe and the fourth pipe.

[0037] In one embodiment, between the connection point of the first pipe and the fourth pipe and the connection point of the fourth pipe and the third pipe, an additional electric door 7 for the soot blowing steam source of the air preheater is provided on the fourth pipe.

[0038] In one embodiment, between the connection point of the first pipe and the fourth pipe and the connection point of the fourth pipe and the third pipe, a new manual door 6 for the air preheater soot blowing steam source is also provided on the fourth pipe.

[0039] In one embodiment, the apparatus further includes a fifth conduit from the auxiliary steam to the air preheater.

[0040] In one embodiment, the fifth pipeline is equipped with an auxiliary steam to air preheater soot blowing isolation door 8 and an auxiliary steam to air preheater soot blowing non-return door 9.

[0041] In one embodiment, a soot blowing steam source regulating valve 3 is provided between the boiler body and the soot blowing safety valve 4 on the first pipeline.

[0042] In one embodiment, a manual soot blowing valve 1 and an electric soot blowing valve 2 are provided between the boiler body and the soot blowing steam source regulating valve 3 on the first pipeline.

[0043] In one embodiment, a denitrification and soot blowing isolation door 11 is provided at the end of the second pipe near the denitrification soot blower.

[0044] In one embodiment, an air preheater soot blowing isolation door 12 is provided at the end of the fourth pipe near the air preheater.

[0045] To enable those skilled in the art to better understand the present invention, the principles of the present invention are explained below in conjunction with the accompanying drawings:

[0046] The air preheater soot blowing steam source consists of two parts: one is the auxiliary steam source, and the other is the boiler body soot blowing steam source. When the coal type varies significantly in ash content, the air preheater needs to continuously blow soot to prevent blockage. Because the auxiliary steam pressure changes in sync with the unit load, sometimes the auxiliary steam supply pressure is less than 1 MPa, which cannot meet the air preheater soot blowing steam source pressure requirements. When the air preheater uses the boiler body soot blowing steam source, this source connects to all soot blowers in the boiler body. During air preheater soot blowing, the soot blowers in other boiler body soot blowers are under pressure. If the soot blower soot blower riser valves are not airtight and leak internally, they can scour and damage the boiler body's heating surfaces, potentially causing surface bursts and unit shutdown.

[0047] If a separate soot blowing pipeline is led from the boiler body soot blowing steam source regulating valve 3 to supply the air preheater soot blower separately from the boiler body soot blower, it can not only ensure the steam supply during continuous soot blowing of the air preheater, but also solve the problems of unstable auxiliary steam supply pressure to the air preheater and long-term pressure in front of the boiler body soot blower lifting valve.

[0048] Considering the mutual steam leakage between systems after the pipeline modification, the pipeline outlet is led out from behind the boiler body soot blowing steam source regulating valve, and an isolation valve is installed. The junction point is connected to the boiler body to air preheater non-return valve and the auxiliary steam to air preheater soot blowing non-return valve 9.

[0049] The on-site survey showed that there was sufficient space for pipeline laying, and the plan was feasible.

[0050] The plan was implemented from July to September 2022, and the modification technology was temporarily applied to Unit 1 of our plant. After Unit 1 was started up in October 2022, the system was put into operation. The steam source pipeline from the boiler body to the sootblower was separated from the steam source pipeline of the boiler body sootblower. When the air preheater sootblower blows soot, the boiler body sootblower is not pressurized, and there is no pressure before the lifting valve of the boiler body sootblower. This eliminates the safety hazard of the lifting valve not being tight enough to flush and damage the heating surface, and ensures the safe operation of the unit.

[0051] A separate soot blowing pipeline is led from the boiler body soot blowing steam source regulating valve 3 to supply soot blowing to the air preheater soot blower, which is separate from the boiler body soot blower. This can not only ensure the steam supply during continuous soot blowing of the air preheater, but also solve the problems of unstable auxiliary steam supply pressure to the air preheater and long-term pressure in front of the boiler body soot blower lifting valve.

[0052] Considering the mutual steam leakage between systems after the pipeline modification, the pipeline outlet is led out from behind the boiler body soot blowing steam source regulating valve, and an isolation valve is installed. The junction point is connected to the boiler body to air preheater non-return valve and the auxiliary steam to air preheater soot blowing non-return valve 9.

[0053] This invention solves two problems:

[0054] The unit load caused the auxiliary steam pressure to the air preheater to be less than 1 MPa, which could not meet the air preheater's soot blowing steam pressure requirements.

[0055] When the air preheater uses the boiler body as the soot blowing steam source, the safety hazards caused by the lifting valve not being tight enough to flush and damage the heating surface are eliminated, ensuring the safe operation of the unit.

[0056] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A soot blowing steam source device for a supercritical boiler unit, characterized in that, include: The first pipe from the boiler body to the furnace soot blower is equipped with a soot blowing safety valve (4). The first pipeline soot blowing safety valve (4) is connected to the furnace soot blower by a second pipeline leading to the denitrification soot blower. A denitrification check valve is installed on the second pipeline. A third pipe leading to the air preheater is connected between the second pipeline denitrification check valve and the denitrification soot blower. A fourth pipe leading to the air preheater is provided between the connection point of the first and second pipes and the soot blowing safety valve (4); A new active electric door (5) is installed on the first pipe between the connection point of the first pipe and the second pipe and between the connection point of the first pipe and the fourth pipe. At the connection point between the first and fourth pipelines, and between the connection point between the fourth and third pipelines, an electric door (7) for the new air preheater soot blowing steam source is installed on the fourth pipeline. The connection point between the first and fourth pipelines, and the connection point between the fourth and third pipelines, is also equipped with a manual door for the air preheater soot blowing steam source (6) on the fourth pipeline; The device also includes a fifth pipeline from the auxiliary steam to the air preheater; The fifth pipeline is equipped with an auxiliary steam to air preheater soot blowing isolation door (8) and an auxiliary steam to air preheater soot blowing non-return door (9).

2. The soot blowing steam source device for a supercritical boiler unit according to claim 1, characterized in that, A soot blowing steam source regulating valve (3) is installed between the boiler body and the soot blowing safety valve (4) on the first pipeline.

3. The soot blowing steam source device for a supercritical boiler according to claim 2, characterized in that, A manual door (1) and an electric door (2) for the soot blowing steam source are installed between the boiler body and the soot blowing steam source regulating door (3) on the first pipeline.

4. The soot blowing steam source device for a supercritical boiler unit according to claim 1, characterized in that, The second pipeline is equipped with a denitrification soot blowing isolation door (11) at the end near the denitrification soot blowing device.

5. A soot blowing steam source device for a supercritical boiler according to claim 1, characterized in that, The fourth pipeline is equipped with an air preheater soot blowing isolation door (12) at the end near the air preheater.

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