Adjusting device and method for coal pulverizing system of coal-fired power plant

Abstract

The invention provides an adjusting device and method for a coal pulverizing system of a coal-fired power plant. The adjusting device comprises a powder feeding pipeline, an adjusting unit and a sealing air pipe. An annular air ring is arranged on the side wall of the powder feeding pipeline; the adjusting unit comprises a first hollow part and a second hollow part, the adjusting unit is arranged on the outer side of the powder feeding pipeline in a sleeving mode, and the first part is connected with the annular air ring in a sealed mode through the second part; a preset included angle is formed between the central axis of the second part and the central axis of the powder feeding pipeline; the sealing air pipe is connected with the first part; high-pressure sealing air sequentially passes through the sealing air pipe, the first part and the second part and is sprayed out at a high speed from the annular air ring to the interior of the powder feeding pipeline, and an annular air curtain barrier is formed in the center of the powder feeding pipeline so as to adjust the air volume of the powder feeding pipeline. The powder feeding system has the technical effects that the design is reasonable, the air volume deviation of all the powder feeding pipelines can be controlled within the preset range all the time, and the combustion working condition of the boiler can be optimized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coal-fired power plant power generation, and particularly relates to a regulating device and method for a coal-fired power plant pulverizing system. BACKGROUND

[0002] At present, if the deviation of primary air powder of a coal-fired power generating unit boiler in service is too large during operation, especially under low load, it will directly lead to unbalanced combustion of the boiler.

[0003] Therefore, a regulating device and method for a coal-fired power plant pulverizing system are urgently needed to effectively control the deviation of primary air of each powder feeding pipe within a preset range, so as to optimize the combustion condition of the boiler. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art, and provide a new technical solution of a regulating device and method for a coal-fired power plant pulverizing system.

[0005] According to a first aspect of the present application, a regulating device for a coal-fired power plant pulverizing system is provided, comprising: a powder feeding pipe, an annular air ring being arranged on a side wall of the powder feeding pipe; a regulating unit, the regulating unit comprising a first part and a second part which are hollow, the regulating unit being arranged on the outside of the powder feeding pipe, and the first part being in sealed connection with the annular air ring through the second part; wherein a preset angle is formed between the central axis of the second part and the central axis of the powder feeding pipe; a sealing air pipe, the sealing air pipe being connected with the first part; high-pressure sealing air is sprayed at high speed from the annular air ring to the inside of the powder feeding pipe through the sealing air pipe, the first part and the second part in sequence, and an annular air curtain barrier is formed at the center of the powder feeding pipe to regulate the air volume of the powder feeding pipe.

[0006] Optionally, the regulating device for the coal-fired power plant pulverizing system further comprises an air volume measuring unit, the air volume measuring unit being arranged on the powder feeding pipe and being used for measuring the air volume in the powder feeding pipe in real time.

[0007] Optionally, the regulating device for the coal-fired power plant pulverizing system further comprises a regulating valve, the regulating valve being arranged on the sealing air pipe and being used for regulating the air volume of high-pressure sealing air in the sealing air pipe.

[0008] Optionally, the regulating device for the coal-fired power plant pulverizing system further comprises a controller, the air volume measuring unit and the regulating valve being connected with the controller, the controller being used for calculating an air volume deviation value according to the measured value of the air volume measuring unit and an air volume set value, and controlling the opening degree of the regulating valve according to the air volume deviation value so that the air volume deviation value is within a preset range.

[0009] Optionally, the regulating device of the coal-fired power plant pulverizing system further comprises a wind pressure monitoring unit and an alarm unit, the wind pressure monitoring unit is arranged in the sealing air pipe and is used for measuring the wind pressure in the sealing air pipe; the wind pressure monitoring unit and the alarm unit are connected with the controller; When the wind pressure in the sealing air pipe is less than a preset threshold, an alarm or interlock protection is triggered.

[0010] Optionally, the preset range is ±5%.

[0011] Optionally, the preset included angle is 30°.

[0012] According to a second aspect of the present application, a regulating method of a coal-fired power plant pulverizing system is provided, comprising the following steps: Step S1, measuring the wind volume in the powder feeding pipe in real time to obtain a wind volume measurement value; Step S2, calculating a wind volume deviation value according to the wind volume measurement value and a wind volume set value; Step S3, controlling the opening of the regulating valve according to the wind volume deviation value, changing the wind volume in the powder feeding pipe by adjusting the wind volume of the high-pressure sealing air in the sealing air pipe, and making the wind volume deviation value within a preset range.

[0013] Optionally, the regulating method of the coal-fired power plant pulverizing system further comprises: measuring the wind pressure in the sealing air pipe, and triggering an alarm or interlock protection when the wind pressure in the sealing air pipe is less than a preset threshold.

[0014] Optionally, when the high-pressure sealing air enters the powder feeding pipe through the annular air ring, the wind direction of the high-pressure sealing air is opposite to the flow direction of the wind-powder in the powder feeding pipe.

[0015] One technical effect of the present application is that: In the embodiments of the present application, the high-pressure sealing air is sequentially sprayed from the annular air ring to the inside of the powder feeding pipe through the sealing air pipe, the first part and the second part, and an annular air curtain barrier is formed in the center of the powder feeding pipe to regulate the wind volume of the powder feeding pipe. Since the air curtain itself produces throttling effect on the coal powder airflow in the powder feeding pipe, by adjusting the wind volume or wind pressure of the sealing air in the sealing air pipe, the stiffness and wind volume of the air curtain can be changed, so as to dynamically change the pipe resistance in the powder feeding pipe, realize the wind volume regulation of the powder feeding pipe and ensure that the wind volume deviation value in the powder feeding pipe is within a preset range, and the boiler combustion condition is better optimized. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 FIG. 1 is a structural schematic view of a regulating device of a coal-fired power plant pulverizing system according to an embodiment of the present application; Figure 2A cross-sectional view of a regulating device of a coal pulverizing system of a coal-fired power plant according to an embodiment of the present application; Figure 3 A flow chart of a regulating method of a coal pulverizing system of a coal-fired power plant according to an embodiment of the present application.

[0017] In the figure: 1, powder conveying pipe; 2, regulating unit; 21, first part; 22, second part; 11, annular air ring; 3, sealing air pipe. DETAILED DESCRIPTION

[0018] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of the components and steps set forth in the embodiments, numerical expressions, and numerical values, unless specifically stated otherwise, do not limit the scope of the present application.

[0019] Embodiments of the present application will be described in detail below, examples of which are shown in the accompanying drawings, in which the same or similar components or components having the same or similar functions are denoted by the same or similar reference numerals throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are intended only for the purpose of explaining the present application, and should not be construed as limiting the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts fall within the scope of the present application.

[0020] The terms "first", "second" in the specification and claims of the present application can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise stated. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally means that the front and rear associated objects are in an "or" relationship.

[0021] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present application.

[0022] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0023] According to the first aspect of the present application, referring to Figure 1 and Figure 2 , a regulating device for a coal-fired power plant pulverizing system is provided, which can fundamentally solve the problems of traditional mechanical shrinkage regulation, such as jamming, easy wear and tear, and large maintenance amount, and can realize that the deviation of the primary air flow of each powder conveying pipe 1 is controlled within ±5%, and the boiler combustion condition is optimized.

[0024] Specifically, the regulating device for the coal-fired power plant pulverizing system comprises: a powder conveying pipe 1, an annular air ring 11 is arranged on the side wall of the powder conveying pipe 1; a regulating unit 2, the regulating unit 2 comprises a first part 21 and a second part 22 which are hollow, the regulating unit 2 is sleeved on the outside of the powder conveying pipe 1, and the first part 21 is sealingly connected with the annular air ring 11 through the second part 22; wherein a preset included angle is formed between the central axis of the second part 22 and the central axis of the powder conveying pipe 1; wherein the regulating unit 2 and the annular air ring 11 form a novel air ring sealing type shrinkage structure; a sealing air pipe 3, the sealing air pipe 3 is connected with the first part 21; high-pressure sealing air is sequentially sprayed from the annular air ring 11 to the inside of the powder conveying pipe 1 through the sealing air pipe 3, the first part 21 and the second part 22 at high speed, and an annular air curtain barrier is formed at the center of the powder conveying pipe 1 to regulate the air flow of the powder conveying pipe 1. Wherein, the high-pressure sealing air can be taken from the outlet of the primary air fan or an independent sealing air fan.

[0025] In the embodiment of the present application, high-pressure sealing air is sequentially sprayed from the annular air ring 11 to the inside of the powder conveying pipe 1 through the sealing air pipe 3, the first part 21 and the second part 22 at high speed, and an annular air curtain barrier is formed at the center of the powder conveying pipe 1 to regulate the air flow of the powder conveying pipe 1. Since the air curtain itself produces throttling effect on the coal powder flow in the powder conveying pipe 1, by adjusting the air flow or air pressure of the sealing air in the sealing air pipe 3, the stiffness and air flow of the air curtain can be changed, so as to dynamically change the pipe resistance in the powder conveying pipe 1, realize the air flow regulation of the powder conveying pipe 1 and ensure that the air flow deviation value of the powder conveying pipe 1 is within the preset range, and the boiler combustion condition is better optimized.

[0026] It should be noted that, since the adjusting unit 2 and the annular air ring 11 form a new type of air ring sealing type orifice structure, the limitations of the traditional mechanical adjusting type orifice are broken, and the traditional mechanical adjusting valve core is abandoned, and the pneumatic sealing and throttling principle is adopted. Among them, the throttling principle is as follows: Because the air curtain itself has a throttling effect on the pulverized coal gas flow in the powder conveying pipe 1, by adjusting the air volume or air pressure of the sealing air, the stiffness and air volume of the air curtain can be changed, thereby dynamically changing the pipeline resistance in each powder conveying pipe 1, thereby realizing the air volume adjustment of the powder pipe. In addition, by cooperating with the closed-loop logic operation system, the air volume deviation in each powder conveying pipe 1 is always controlled within ±5%. Further, the high-speed air curtain simultaneously isolates the direct contact of the pulverized coal and the new type of air ring sealing type orifice structure, and fundamentally eliminates the disadvantages of the traditional orifice that cannot be adjusted due to the long-term accumulation of coal powder in the components.

[0027] Optionally, the adjusting device of the coal-fired power plant pulverizing system further comprises an air volume measuring unit, which is arranged in the powder conveying pipe 1 and is used for measuring the air volume in the powder conveying pipe 1 in real time. For example, the air volume measuring unit can adopt a wind-powder online monitoring device based on the differential pressure principle.

[0028] In the above embodiment, the air volume measuring unit can accurately and in real time measure the air volume in the powder conveying pipe 1, thereby helping to accurately adjust the air volume in each powder conveying pipe 1.

[0029] Optionally, the adjusting device of the coal-fired power plant pulverizing system further comprises an adjusting valve, which is arranged in the sealing air pipe 3 and is used for adjusting the air volume of the high-pressure sealing air in the sealing air pipe 3. For example, the adjusting valve can be pneumatic or electric. The adjusting valve can better adjust the air volume of the high-pressure sealing air in the sealing air pipe 3, thereby helping to adjust the air volume deviation value in each powder conveying pipe 1.

[0030] Optionally, the adjusting device of the coal-fired power plant pulverizing system further comprises a controller, the air volume measuring unit and the adjusting valve are connected with the controller, and the controller is used for calculating an air volume deviation value according to a measured value of the air volume measuring unit and an air volume set value, and controlling the opening degree of the adjusting valve according to the air volume deviation value so that the air volume deviation value is within a preset range.

[0031] In the above embodiment, the opening degree of the adjusting valve can be effectively adjusted by the controller, thereby better ensuring that the air volume deviation value in each powder conveying pipe 1 is within a preset range.

[0032] Optionally, the adjusting device of the coal-fired power plant pulverizing system further comprises a wind pressure monitoring unit and an alarm unit, the wind pressure monitoring unit is arranged in the sealing air pipe 3 and is used for measuring the wind pressure in the sealing air pipe 3; the wind pressure monitoring unit and the alarm unit are connected with the controller. When the air pressure in the sealing air pipe 3 is less than a preset threshold value, an alarm or interlock protection is triggered, and measures such as reducing the output of the coal mill or cutting the mill can be taken.

[0033] In the above embodiment, the minimum pressure difference required for effective sealing and throttling of the air curtain in the powder feeding pipe 1 can be ensured, and the safe and stable operation of the regulating device of the coal-fired power plant pulverizing system can be ensured.

[0034] Optionally, the preset range is ±5%. This helps to ensure that the flow in each powder feeding pipe 1 approaches balance, thereby optimizing the boiler combustion condition.

[0035] Optionally, the preset included angle is 30°. This helps to ensure the effectiveness of the novel air ring sealing type contraction hole structure formed by the regulating unit 2 and the annular air ring 11, so that an air curtain barrier can be formed in the powder feeding pipe 1.

[0036] In the embodiments of the present application, the regulating device of the coal-fired power plant pulverizing system not only prolongs the service life of the coal-fired power plant pulverizing system, completely eliminates coal powder erosion and wear, doubles the service life of the equipment, greatly reduces the replacement frequency and spare parts cost, but also has a simple and reliable structure, significantly reduces the maintenance cost and workload, basically realizes "maintenance-free", reduces the operation and maintenance intensity of the power plant and the shutdown loss. Further, precise, rapid and automatic regulation can be realized, which lays a solid foundation for optimizing the air-powder ratio, improving the boiler combustion efficiency and responding to load changes.

[0037] In addition, the regulating device of the coal-fired power plant pulverizing system not only has excellent sealing and environmental protection, i.e. the dynamic air curtain effectively isolates coal powder leakage, greatly improves the working environment, reduces the safety risk, and meets the increasingly strict environmental protection requirements, but also improves the system operation reliability, i.e. avoids mechanical jamming failure, reduces unplanned mill shutdown, and improves the unit operation stability. In addition, based on the optimized system design, key hardware support is provided for intelligent upgrading of the pulverizing system and full-automatic combustion control.

[0038] According to a second aspect of the present application, referring to Figure 3 , a regulating method of a coal-fired power plant pulverizing system is provided, comprising the following steps: Step S1, measuring the air volume in the powder feeding pipe 1 in real time to obtain an air volume measurement value; Step S2, calculating an air volume deviation value according to the air volume measurement value and an air volume set value; Step S3, controlling the opening degree of the regulating valve according to the air volume deviation value, changing the air volume in the powder feeding pipe 1 by adjusting the air volume of the high-pressure sealing air in the sealing air pipe 3, and making the air volume deviation value within a preset range.

[0039] In the above-mentioned embodiments, by virtue of the innovative pneumatic throttling and sealing principle, the core problems of wear, leakage, jamming, and large maintenance amount faced by the traditional mechanical throttle in the application of the coal-fired power plant pulverizing system are effectively solved. The introduction of the regulating unit 2 and the sealing air pipe 3 brings the advantages of super-long service life, extremely low maintenance, precise control, and excellent sealing, and the like, and thus the device has significant comprehensive competitiveness in economy, safety, and environmental protection in long-term operation, and is an advanced technical direction to replace the traditional mechanical throttle, and is especially suitable for modern power plants with high requirements for reliability, automation level, and environmental protection.

[0040] Optionally, the regulating method of the coal-fired power plant pulverizing system further comprises: The air pressure in the sealing air pipe 3 is measured, and when the air pressure in the sealing air pipe 3 is less than a preset threshold value (i.e., the air pressure in the sealing air pipe 3 is lower than the minimum effective sealing differential pressure), an alarm or interlock protection is triggered. That is, when the sealing air differential pressure in each sealing air pipe 3 is abnormal, the air volume regulating function of each sealing air pipe 3 will fail, at which time, the system alarms and triggers the interlock protection of the coal mill.

[0041] In the above-mentioned embodiments, the stability of the regulating device of the coal-fired power plant pulverizing system is helped to be ensured, so that the coal mill is better protected.

[0042] Optionally, the air direction of the high-pressure sealing air when entering the pulverizing pipe 1 through the annular air ring 11 is opposite to the flow direction of the air and coal powder in the pulverizing pipe 1. This helps to form an annular air curtain barrier in the center of the pulverizing pipe 1, so that the air volume of the pulverizing pipe 1 can be better regulated. It can be understood that the above-mentioned embodiments are only exemplary embodiments for illustrating the principles of the present application, and the present application is not limited thereto. Various modifications and improvements can be made by those of ordinary skill in the art without departing from the spirit and essence of the present application, and these modifications and improvements are also considered to be within the protection scope of the present application.

Claims

1. A regulating device for a pulverizing system in a coal-fired power plant, characterized in that, include: A powder feeding pipe, wherein an annular air ring is provided on the side wall of the powder feeding pipe; An adjustment unit comprising a hollow first part and a hollow second part, the adjustment unit being sleeved on the outside of the powder feeding pipe, and the first part being sealed to the annular air ring through the second part; wherein, the central axis of the second part forms a preset angle with the central axis of the powder feeding pipe; A sealed air duct, which is connected to the first part; High-pressure sealing air is sequentially ejected from the annular air ring into the powder delivery pipe through the sealing air duct, the first part, and the second part, forming an annular air curtain barrier in the center of the powder delivery pipe to regulate the air volume of the powder delivery pipe.

2. The regulating device for a coal-fired power plant pulverizing system according to claim 1, characterized in that, It also includes an air volume measurement unit, which is installed in the powder delivery pipe and is used to measure the air volume in the powder delivery pipe in real time.

3. The regulating device for a coal-fired power plant pulverizing system according to claim 2, characterized in that, It also includes a regulating valve, which is installed in the sealed air duct and is used to regulate the air volume of the high-pressure sealing air in the sealed air duct.

4. The regulating device for a coal-fired power plant pulverizing system according to claim 3, characterized in that, It also includes a controller, and the air volume measurement unit and the regulating valve are both connected to the controller. The controller is used to calculate the air volume deviation value based on the measurement value of the air volume measurement unit and the air volume set value, and to control the opening of the regulating valve based on the air volume deviation value so that the air volume deviation value is within a preset range.

5. The regulating device for a coal-fired power plant pulverizing system according to claim 4, characterized in that, It also includes a wind pressure monitoring unit and an alarm unit. The wind pressure monitoring unit is installed in the sealed air duct and is used to measure the wind pressure inside the sealed air duct. Both the wind pressure monitoring unit and the alarm unit are connected to the controller. When the air pressure inside the sealed duct is less than a preset threshold, an alarm or interlock protection is triggered.

6. The regulating device for a coal-fired power plant pulverizing system according to claim 5, characterized in that, The preset range is ±5%.

7. The regulating device for a coal-fired power plant pulverizing system according to claim 6, characterized in that, The preset included angle is 30°.

8. A method for regulating a pulverizing system in a coal-fired power plant, characterized in that, Includes the following steps: Step S1: Measure the air volume in the powder delivery duct in real time to obtain the air volume measurement value; Step S2: Calculate the air volume deviation value based on the measured air volume value and the set air volume value; Step S3: Control the opening of the regulating valve according to the air volume deviation value, change the air volume in the powder delivery pipe by adjusting the air volume of the high-pressure sealing air in the sealed air duct, and make the air volume deviation value within the preset range.

9. The adjustment method for a coal-fired power plant pulverizing system according to claim 8, characterized in that, Also includes: The system measures the air pressure inside the sealed duct. When the air pressure inside the sealed duct is less than a preset threshold, an alarm or interlock protection is triggered.

10. The adjustment method for a coal-fired power plant pulverizing system according to claim 9, characterized in that, When the high-pressure sealing air enters the powder delivery pipe through the annular air ring, the air direction is opposite to the flow direction of the air and powder inside the powder delivery pipe.

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