Steam soot blowing steam source supply system of coal-fired boiler

Abstract

The utility model relates to a coal-fired boiler steam soot blowing steam source supply system which comprises a steam source supply system body which is composed of a first pipeline, a second pipeline and a third pipeline which are arranged in parallel. One ends of the first pipeline, the second pipeline and the third pipeline are respectively connected with an outlet of a rear screen superheater, an outlet of a low-temperature reheater and an outlet of a reheater temperature reduction water mother pipe, and the other ends of the first pipeline, the second pipeline and the third pipeline are connected to a soot blower after being merged into a pipeline with a safety valve; the first pipeline is a steam soot blowing high-pressure steam source pipeline, the second pipeline is a low-pressure soot blowing steam source pipeline, the third pipeline is a temperature reduction pipeline, and the first pipeline and the third pipeline serve as standby air sources of the second pipeline and are used for soot blowing of a boiler through a soot blower. The utility model has the advantages of simple and reasonable structure, practicability, convenience and the like.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of steam soot blowing system of thermal power plant, and relates to a coal-fired boiler steam soot blowing steam source supply system. BACKGROUND

[0002] At present, the steam soot blowing steam source of the boiler body of the 600MW thermal power plant is mostly taken from the outlet steam of the back screen superheater, and the steam source has high pressure and high temperature, and is reduced to about 2.5MPa and 390 DEG C, and then is supplied to the soot blower for soot blowing.

[0003] The high-temperature and high-pressure steam soot blowing steam source system has high requirements for the soot blowing valve and the pressure reducing device, and the equipment is seriously eroded, and the problems of internal leakage of the electric valve, air leakage of the packing, sticking of the valve, blowing of the valve core and valve seat, and adjustment failure are prone to occur in the operation process, and the adjustment failure of the valve leads to the action of the soot blowing safety valve for several times, so that the equipment has many defects and the reliability of the equipment is affected.

[0004] When the above-mentioned faults occur, the boiler body cannot be sooted in time, which may further cause the boiler coking and other faults, and threatens the safe and stable operation of the unit.

[0005] On the other hand, the throttling loss is large when the high-temperature and high-pressure steam is throttled and reduced in pressure for soot blowing, and the economy of the unit is affected.

[0006] Therefore, the coal-fired boiler steam soot blowing steam source supply system is designed to overcome the above-mentioned problems. UTILITY MODEL CONTENTS

[0007] The utility model aims at overcoming the defects of the prior art, and provides a coal-fired boiler steam soot blowing steam source supply system which has the advantages of simple and reasonable structure, convenience, stable operation, and high working efficiency.

[0008] The utility model is realized by the following technical scheme: a coal-fired boiler steam soot blowing steam source supply system, which comprises a steam source supply system body, the steam source supply system body is composed of a first pipeline, a second pipeline and a third pipeline which are arranged in parallel with each other, one end of the first pipeline, the second pipeline and the third pipeline is connected with the outlet of the back screen superheater, the outlet of the low-temperature reheater and the outlet of the reheater desuperheating water mother pipe respectively, the other end of the first pipeline, the second pipeline and the third pipeline is connected to a soot blower through a pipeline which is provided with a safety valve, the first pipeline is a steam soot blowing high-pressure steam source pipeline, the second pipeline is a low-pressure soot blowing steam source pipeline, the third pipeline is a desuperheating pipeline, and the first pipeline and the third pipeline are used as the standby gas source of the second pipeline for the soot blower to blow the soot of the boiler.

[0009] As preferred, the first pipeline is sequentially provided with a first stop valve, a first electric stop valve, a first pneumatic regulating valve and a second stop valve.

[0010] As preferred: the third stop valve, the second electric stop valve, the second pneumatic regulating valve, the desuperheater, the first check valve and the fourth stop valve are sequentially arranged on the second pipeline, the desuperheater on the second pipeline is connected with the third pipeline, and the fourth stop valve on the second pipeline is connected with the first pipeline.

[0011] As preferred: the fifth stop valve, the sixth stop valve, the third electric stop valve, the third pneumatic regulating valve and the second check valve are sequentially arranged on the third pipeline, and the third pipeline is used for cooling the second pipeline.

[0012] As preferred: the branch pipeline is arranged between the third electric stop valve and the third pneumatic regulating valve on the third pipeline, the branch pipeline is provided with a first drain valve and a second drain valve, and the first drain valve and the second drain valve are used for draining condensate generated on the third pipeline and ensuring normal operation of the third pipeline.

[0013] As preferred: the pressure gauges and the temperature gauges are arranged on the first pipeline, the second pipeline and the third pipeline, and are used for preventing the pipelines from being damaged due to overheating.

[0014] As preferred: the first stop valve, the second stop valve, the third stop valve, the fourth stop valve, the fifth stop valve and the sixth stop valve on the first pipeline, the second pipeline and the third pipeline are manual valves, and the other valves are electric valves, and the other valves can be remotely controlled through a PLC controller.

[0015] The beneficial effects of the utility model are as follows:

[0016] The coal-fired boiler steam soot-blowing steam source supply system designed in the utility model draws a reheat steam (second pipeline) as a low-pressure soot-blowing steam source through a connecting pipe between a low-temperature reheater outlet header and a high-temperature reheater inlet header, the low-pressure soot-blowing steam source is added into a first pipeline (high-pressure steam soot-blowing steam source system) after passing through a pressure and temperature reducing regulating station (third pipeline) and is used as a normal operation soot-blowing steam source, and a high-pressure soot-blowing steam source of a rear platen superheater is used as a standby steam source, thereby further increasing the system reliability. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a whole structure schematic view of the utility model. DETAILED DESCRIPTION

[0018] In order for those ordinary skilled in the art to more clearly understand the purpose, technical scheme and advantages of the utility model, the utility model is further described below in combination with the drawings and embodiments.

[0019] In the description of the utility model, it is understood that the orientation or position relation indicated by the terms such as ''up'', ''down'', ''left'', ''right'', ''inner'', ''outer'', ''horizontal direction'', ''vertical direction'' is the orientation or position relation based on the orientation or position relation shown in the drawing, and is only for the convenience of describing the utility model, and does not indicate or imply that the indicated device or element must have a particular orientation, so it cannot be understood as a limitation on the utility model.

[0020] The utility model will be described in detail below in combination with the drawings: as Figure 1 The utility model discloses a coal-fired boiler steam soot-blowing steam source supply system, including steam source supply system body, steam source supply system body is by the parallelly connected first pipe 20, second pipe 21 and third pipe 22, one end of first pipe 20, second pipe 21 and third pipe 22 is connected with rear screen superheater export, low temperature reheater export and reheater desuperheating water mother pipe export respectively, and the other end of first pipe 20, second pipe 21 and third pipe 22 is connected to soot-blower after being connected to soot-blower in a pipe with safety valve 16, and first pipe 20 is as steam soot-blowing high pressure steam source pipe, second pipe 21 is as low pressure soot-blowing steam source pipe, third pipe 22 is as desuperheating pipe, and first pipe 20, third pipe 22 are as the standby gas source of second pipe 21, and the soot-blower is used to carry out soot-blowing to boiler.

[0021] First stop valve 1, first electric stop valve 2, first pneumatic regulating valve 3, second stop valve 14 are sequentially arranged on the first pipe 20.

[0022] Third stop valve 4, second electric stop valve 5, second pneumatic regulating valve 6, desuperheater 13, first check valve 7, fourth stop valve 15 are sequentially arranged on the second pipe 21, and the desuperheater 13 on the second pipe 21 is connected with the third pipe, and the pipe body on the fourth stop valve 15 away from the desuperheater 13 side on the second pipe 21 is connected with the first pipe 20.

[0023] Fifth stop valve 8, sixth stop valve 9, third electric stop valve 10, third pneumatic regulating valve 11, second check valve 12 are sequentially arranged on the third pipe 22, and are used to cool the second pipe 21.

[0024] Branch pipe 19 is arranged between third electric stop valve 10 and third pneumatic regulating valve 11 on the third pipe 22, and hydrophobic primary valve 17 and hydrophobic secondary valve 18 are arranged on the branch pipe 19, which is used to discharge the condensate generated on the third pipe 22, and guarantee the normal operation of the third pipe 22.

[0025] Pressure gauge and temperature gauge (not shown in the drawing) are arranged on the first pipe 20, the second pipe 21 and the third pipe 22, which are used to prevent the pipeline from being damaged due to overheating.

[0026] The first stop valve 1, the second stop valve 14, the third stop valve 4, the fourth stop valve 15, the fifth stop valve 8 and the sixth stop valve 9 on the first pipeline 20, the second pipeline 21 and the third pipeline 22 are manual valves, and the remaining valves are electric valves, which can be remotely controlled by a PLC controller.

[0027] The design features and working process of the utility model are as follows:

[0028] The low reexport to the furnace body soot blowing steam source has the operating condition, in order to improve the economy, low pressure soot blowing steam source should be used preferentially, under normal circumstances, the low reexport steam source of the second pipeline is used as normal soot blowing steam source, and the rear screen superheater outlet steam source of the first pipeline is used as standby steam source. The manual isolation valves of the screen superheater soot blowing steam source and the low reexport soot blowing steam source cannot be opened simultaneously. When low reexport steam source is used for soot blowing, the temperature of the second pipeline should be controlled between 330 DEG C and 380 DEG C, otherwise soot blowing cannot be carried out, to prevent the steam overheating degree being too low to cause soot blowing steam to carry water, thereby causing the furnace tube to be damaged. A part of cold water can be in the pipe inside when the standby soot blowing steam source is not used for a long time, and the manual door should be slowly opened according to the temperature change of the second pipeline (soot blowing mother pipe) when the pipe is warmed up before steam source switching, to prevent pipeline vibration. When the low reexport to the furnace body soot blowing system fails, the low reexport steam source of the second pipeline can be switched to for soot blowing.

[0029] The coal-fired boiler steam soot blowing steam source supply system designed in the utility model can reduce the use frequency of high-temperature and high-pressure steam source for soot blowing, reduce equipment requirements, reduce the scouring of equipment, avoid problems such as electric valve internal leakage, packing air leakage, valve jamming, valve core and valve seat blowout and adjustment failure, and improve equipment reliability. On the other hand, the throttling loss of high-pressure steam throttled and depressurized for soot blowing use can be reduced, and the economic efficiency of the unit can be improved. Embodiment

[0030] The utility model is further described below in combination with the normal state and the maintenance state of boiler soot blowing, and it is particularly pointed out that the low-temperature reheater steam source of the second pipeline is selected as the boiler steam soot blowing operating steam source, and the rear screen superheater steam source is selected as the standby steam source in the following examples, and the selection should be distinguished according to the on-site equipment in actual application.

[0031] When the unit is normally operated, the low reexport steam source is used for soot blowing, the soot blowing steam source of the rear screen superheater outlet is standby, and the first stop valve 1, the first electric stop valve 2, the first pneumatic regulating valve 3 and the second stop valve 14 are in the closed state.

[0032] When the second electric cut-off valve 5, the second pneumatic regulating valve 6, the desuperheater 13 or the second pipeline (low-pressure soot blowing steam source pipeline) fails, and needs to be isolated for maintenance, the following steps can be followed:

[0033] S1, close the third pneumatic regulating valve 11 (reheater desuperheater to low-reheat soot blowing steam source desuperheater pneumatic regulating valve);

[0034] S2, close the third electric cut-off valve 10 (reheater desuperheater to low-reheat soot blowing steam source desuperheater electric cut-off valve);

[0035] S3, close the second pneumatic regulating valve 6 (low-reheat soot blowing steam source pneumatic regulating valve);

[0036] S4, close the second electric cut-off valve 5 (low-reheat soot blowing steam source electric cut-off valve);

[0037] S5, close the fifth cut-off valve 8 (reheater desuperheater to low-reheat soot blowing steam source desuperheater cut-off valve 1);

[0038] S6, close the sixth cut-off valve 9 (reheater desuperheater to low-reheat soot blowing steam source desuperheater cut-off valve 2);

[0039] S7, close the fourth cut-off valve 15 (low-reheat soot blowing steam source cut-off valve);

[0040] S8, close the third cut-off valve 4 (low-reheat soot blowing steam source cut-off valve).

[0041] In the case of effective isolation of the low-reheat soot blowing steam source of the second pipeline, the first cut-off valve 1 (screening soot blowing steam source cut-off valve), the first electric cut-off valve, the first pneumatic regulating valve 3, and the second cut-off valve 14 can be opened to perform boiler body soot blowing.

[0042] As can be seen from the above example, after the boiler steam soot blowing steam source supply system is used, during the maintenance process of the low-pressure soot blowing steam source of the second pipeline or the first pipeline of the rear superheater, the other soot blowing steam source is in a standby state, which overcomes the disadvantage that the original single soot blowing steam source system cannot blow soot in the maintenance process of the soot blowing steam source pipeline or equipment.

[0043] The specific embodiments described herein are merely illustrative of the principles of the present application and its efficacy, and are not intended to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept disclosed by the present application shall be covered by the claims of the present application.

Claims

1. A coal-fired boiler steam sootblowing steam supply system comprising a steam supply system body, characterized by: The steam source supply system body is composed of a first pipeline (20), a second pipeline (21) and a third pipeline (22) arranged in parallel with each other, one end of the first pipeline (20), the second pipeline (21) and the third pipeline (22) is connected with the back screen superheater outlet, the low-temperature reheater outlet and the reheater desuperheating water mother pipe outlet respectively, the other end of the first pipeline (20), the second pipeline (21) and the third pipeline (22) is connected to the soot blower after being connected to a pipeline with a safety valve (16), the first pipeline (20) is a steam soot blowing high-pressure steam source pipeline, the second pipeline (21) is a low-pressure soot blowing steam source pipeline, the third pipeline (22) is a desuperheating pipeline, and the first pipeline (20) and the third pipeline (22) serve as a backup gas source of the second pipeline (21) for the soot blower to blow the boiler.

2. The coal-fired boiler steam sootblowing steam source supply system of claim 1, wherein: The first pipeline (20) is sequentially provided with a first stop valve (1), a first electric stop valve (2), a first pneumatic regulating valve (3) and a second stop valve (14).

3. A coal-fired boiler steam sootblowing steam supply system according to claim 1 or 2, characterised in that: The second pipeline (21) is sequentially provided with a third stop valve (4), a second electric stop valve (5), a second pneumatic regulating valve (6), a desuperheater (13), a first check valve (7) and a fourth stop valve (15), the desuperheater (13) on the second pipeline (21) is connected with the third pipeline, and the fourth stop valve (15) on the second pipeline (21) is connected with the first pipeline (20) at the side of the pipe body away from the desuperheater (13).

4. The coal-fired boiler steam sootblowing steam source supply system of claim 3, wherein: The third pipeline (22) is sequentially provided with a fifth stop valve (8), a sixth stop valve (9), a third electric stop valve (10), a third pneumatic regulating valve (11) and a second check valve (12) for cooling the second pipeline (21).

5. The coal-fired boiler steam sootblowing steam source supply system of claim 4, wherein: The third pipeline (22) is provided with a branch pipeline (19) between the third electric stop valve (10) and the third pneumatic regulating valve (11), the branch pipeline (19) is provided with a primary drain valve (17) and a secondary drain valve (18) for draining the condensate generated on the third pipeline (22) to ensure normal operation of the third pipeline (22).

6. The coal-fired boiler steam sootblowing steam source supply system of claim 5, wherein: Pressure gauges and temperature gauges are arranged on the first pipeline (20), the second pipeline (21) and the third pipeline (22) to prevent the pipelines from being damaged due to overheating.

7. The coal-fired boiler steam sootblowing steam supply system of claim 1 or 6, wherein: The first stop valve (1), the second stop valve (14), the third stop valve (4), the fourth stop valve (15), the fifth stop valve (8) and the sixth stop valve (9) on the first pipeline (20), the second pipeline (21) and the third pipeline (22) are manual valves, and the remaining valves are electric valves which can be remotely controlled through a PLC controller.

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