Primary air whole-process self-adaptive control optimization system

Abstract

The utility model discloses a primary air whole-process self-adaptive control optimization system which comprises a fan system, the fan system comprises a controller, the controller is connected with a primary fan, the primary fan is connected with a hot primary air pipe with an air pre-heater through a pipeline, and the hot primary air pipe is connected with a hot secondary air pipe with an air pre-heater through a pipeline. A cold primary air pipe is connected to the portion, between the inlet end of the air pre-heater and the primary fan, of the hot primary air pipe, the cold primary air pipe and the portion, at the outlet end of the air pre-heater, of the hot primary air pipe are converged and then connected with a coal mill, and the upper end of the coal mill is connected with two coal mill outlets. And at least one electric wind shield in communication connection with the controller is arranged in each of the hot primary air pipe and the cold primary air pipe. According to the invention, the primary air pressure can be adjusted, the throttling loss of a hot air door is reduced, the power consumption of a primary fan is reduced, and the overall operation efficiency of the unit is improved; the structure is simple and practicability is high.

Description

Technical Field

[0001] The utility model relates to a primary wind optimization system, more specifically, to a primary wind full-process adaptive control optimization system, and belongs to the field of power plants. Background Art

[0002] The power consumption of the primary fan of the coal mill is affected by many factors, not only by the unit load and the throttling size of the damper, but also by the fan air volume and air pressure during design. When the unit load fluctuates greatly, the fan cannot operate in the best state, resulting in low fan efficiency and increased power consumption. Utility Model Content

[0003] The utility model aims to provide a primary air full-process adaptive control optimization system which has the technical characteristics of being able to reduce the power consumption of a primary fan, improve the overall operating efficiency of the unit, and having a simple structure and strong practicality.

[0004] In order to achieve the above purpose, the utility model is implemented by the following technical solutions:

[0005] A full-process adaptive control optimization system for primary air comprises a fan system, wherein the fan system comprises a controller, wherein the controller is connected to a primary fan, wherein the primary fan is connected to a hot primary air duct with an air preheater through a pipeline, wherein a cold primary air duct is connected to the hot primary air duct between the air preheater inlet and the primary fan, wherein the cold primary air duct is connected to a coal mill after being merged with the hot primary air duct at the air preheater outlet, wherein two coal mill outlets are connected to the upper end of the coal mill, and wherein at least one electric wind shield connected to the controller for communication is provided in the hot primary air duct and the cold primary air duct.

[0006] Preferably, flow meters are provided in the hot primary air duct and the cold primary air duct, and the flow meters are communicatively connected with the controller; the flow meter in the cold primary air duct is close to its outlet end, and the flow meter in the hot primary air duct is close to the inlet end of the coal mill.

[0007] Preferably, the primary fan includes a primary fan A and a primary fan B, the hot primary air duct connected to the primary fan A is a No. 1 hot primary air duct, the hot primary air duct connected to the primary fan B is a No. 2 hot primary air duct, and two air supply lines are connected between the No. 1 hot primary air duct and the No. 2 hot primary air duct;

[0008] Among them, the two ends of one air supply pipeline are respectively connected to the outlet end of an air preheater, and the two ends of another air supply pipeline 7 are respectively connected to the outlet ends of the primary fan A and the primary fan B.

[0009] Preferably, a sealed air duct is led out from the cold primary air duct to act on the sealing air of the coal mill outlet gate to prevent coal powder from spraying out and polluting the environment.

[0010] Preferably, the primary fan is an axial flow fan with adjustable blades, which is provided with a hydraulic control oil system, which includes a hydraulic oil return pipe and two hydraulic control oil pumps, and a cooler is provided on the hydraulic oil return pipe to cool the hydraulic oil return oil with closed cooling water.

[0011] Preferably, electric wind shields are connected to the hot primary air ducts at both ends of the air preheater, the hot primary air ducts at the outlet of the primary fan, and the hot primary air ducts near the coal mill.

[0012] Preferably, a muffler is connected to the inlet end of the primary fan.

[0013] Preferably, the cold primary air duct is also provided with a cold air duct with an electric wind shield, and the cold air duct is directly connected to the coal mill.

[0014] Beneficial effects: It can adjust the primary air pressure, reduce the throttling loss of the hot air door, reduce the power consumption of the primary fan, and improve the overall operating efficiency of the unit; it has a simple structure and strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0016] Figure 2 It is a schematic diagram of the connection between the hot primary air duct and the cold primary air duct of the utility model. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings, but the present invention is not limited to the following embodiments.

[0018] like Figure 1-2 The figure shows a specific embodiment of the full-process adaptive control optimization system for primary air, which includes a fan system. The fan system includes a controller, and the controller is connected to a primary fan 3. The primary fan 3 is connected to a hot primary air duct 6 with an air preheater 4 (air preheater) through a pipeline. The hot primary air duct 6 between the inlet end of the air preheater 4 and the primary fan 3 is connected to a cold primary air duct 5. The cold primary air duct 5 is connected to a coal mill 1 after being merged with the hot primary air duct 6 at the outlet end of the air preheater 4. Two coal mill outlets are connected to the upper end of the coal mill 1. At least one electric wind shield 2 communicatively connected to the controller is provided in the hot primary air duct 6 and the cold primary air duct 5.

[0019] The function of the primary air provided by the primary fan 3 in this application is to dry and transport the coal powder, including the drying ventilation volume during pulverizing and the coal grinding ventilation volume. Among them, the function of the drying ventilation volume in the hot primary air duct 6 is to provide heat to the raw coal entering the furnace, complete the drying effect of the coal during the grinding process, and maintain the ventilation volume required for the coal volume corresponding to the outlet temperature of the coal mill, and the ventilation volume in the cold primary air duct 5 is required to carry and transport the coal powder.

[0020] The outlet of the primary air fan 3 divides the primary air into two paths, which enter the cold primary air duct 5 (cold air main duct) and the hot primary air duct 6 (hot air main duct) respectively. The primary air entering the cold air main duct is used as temperature-adjusting air and does not pass through the air preheater 4, while the primary air entering the hot air main duct needs to be heated by the air preheater 4. The cold primary air duct 5 and the hot primary air duct 6 are set to introduce cold air and hot air into the coal mill 1. Specifically, the cold primary air duct 5 and the hot primary air duct 6 are connected to the coal mill 1 after being collected, and the gases are mixed and sent to the coal mill 1. The controller can control the electric windshield 2 to adjust the wind pressure of the cold primary air duct 5 and the hot primary air duct 6 to ensure the pulverizing effect of the coal mill, and the cold air of the cold primary air duct 5 can adjust the air-coal ratio of the coal mill and the suitability of the outlet temperature, which is conducive to the increase of the primary air speed and the increase of the coal carrying capacity.

[0021] When the wind pressure is too low, the opening and closing degree of the electric wind shield 2 is reduced to avoid blockage of the coal powder pipe and flame damage to the burner; when the wind pressure is too high, the coal powder particles become coarser. By increasing the opening and closing degree of the electric wind shield 2, the wind pressure is reduced to avoid an increase in the probability of wear and tear of the coal powder pipe elbow and incomplete combustion under the same conditions, which leads to a decrease in the operating efficiency of the unit and a decrease in economic benefits.

[0022] The technical solution of the present application can reduce the primary air pressure when the ventilation volume of the coal mill 1 is constant. Specifically, the opening degree of the electric wind shield 2 in the hot primary air duct 6 can be increased to reduce the throttling loss of the hot air door, so as to reduce the power consumption of the primary fan and improve the overall operating efficiency of the unit. The structure is simple and practical.

[0023] In a preferred embodiment, flow meters are provided in both the hot primary air duct 6 and the cold primary air duct 5, and the flow meters are communicatively connected with the controller; the flow meter in the cold primary air duct 5 is close to its outlet end, and the flow meter in the hot primary air duct 6 is close to the inlet end of the coal mill 1, and real-time data feedback is achieved by the flow meters to achieve efficient control.

[0024] In a preferred embodiment, the primary fan 3 includes a primary fan A and a primary fan B, the hot primary air duct 6 connected to the primary fan A is a No. 1 hot primary air duct, and the hot primary air duct 6 connected to the primary fan B is a No. 2 hot primary air duct, and two air supply pipelines 7 are connected between the No. 1 hot primary air duct and the No. 2 hot primary air duct; wherein, both ends of one air supply pipeline 7 are respectively connected to the outlet end of an air preheater 4, and both ends of the other air supply pipeline 7 are respectively connected to the outlet ends of the primary fan A and the primary fan B.

[0025] The design of primary fan A and primary fan B can achieve single-sided isolation of the primary fan to avoid overall shutdown (during the isolation process, the disturbance to the other primary fan and the boiler should be minimized).

[0026] The method of isolating the primary fan on one side: reduce the unit load to about 300MW, keep the coal mill 1 running, change the rotor blades of the primary fan to be stopped from "automatic" to "manual", gradually close the rotor blades of the primary fan to be stopped, confirm that the rotor blades of the other primary fan are automatically opened, maintain the pressure of the hot primary air duct 6 at about 11.0kPa, and closely monitor the pressure of the hot primary air duct 6, the current of the two primary fans, and the inlet flow rate changes to be normal. If a primary fan is found to be stalled during operation, the rotor blades of the other primary fan should be opened immediately, and the rotor blades of the stalled fan should be closed to make it out of the stall zone, while maintaining the pressure of the hot primary air duct 6 normal. When the rotor blades of the primary fan to be stopped are fully closed, close its outlet electric wind shield 2, shut down the primary fan to be isolated, and confirm that the speed of the shut-down fan is zero, pay attention to prevent the fan from reversing.

[0027] In a preferred embodiment, a sealing air duct 8 is led out from the cold primary air duct 5 to act on the sealing air of the outlet gate of the coal mill 1 to prevent coal powder from spraying out and polluting the environment. Generally, the boiler adopts positive pressure direct blowing, and the pressure in the coal mill 1 is about 9.52kPa. Therefore, another channel is led out from the cold primary air duct 5 as the sealing air of the coal mill to prevent coal powder or hot primary air from leaking out from the loose parts of the grinding bowl, grinding roller, coal feeder, etc. of the coal mill 1, so that the rotating parts of the coal mill and the coal feeder are not damaged by coal powder.

[0028] In a preferred embodiment, the primary fan 3 is an axial flow fan with adjustable blades, adopts a two-stage impeller, has a rated flow rate of 131m3 / s, and a rated outlet pressure of 15.68kPa. The axial flow fan with adjustable blades is provided with a hydraulic control oil system, which includes a hydraulic oil return pipe and two hydraulic control oil pumps. A cooler is provided on the hydraulic oil return pipe to cool the hydraulic oil return oil with closed cooling water.

[0029] Since the hydraulic control oil system is equipped with two hydraulic control oil pumps, one is in operation and the other is in standby during normal operation. Closed cooling water is used to cool the hydraulic oil return oil to control the hydraulic oil temperature.

[0030] Forced oil lubrication can be used for the bearings of the primary fan 3. Specifically, a bearing lubricating oil system can be set up. The bearing lubricating oil system is used to lubricate and cool the main bearings of the primary fan. It is mainly composed of two lubricating oil pumps, an oil cooler, and a filter. The lubricating oil is pressurized by the oil pump, cooled by the oil cooler, and filtered out impurities by the filter to provide lubricating oil for the fan bearings, and then returned to the oil tank. A pressure relief valve is provided on the outlet main pipe of the oil pump to adjust the pressure of the lubricating oil main pipe. The cooling water source of the oil cooler is closed water, and an electric heater is installed in the lubricating oil tank to control the oil temperature in the oil tank.

[0031] Run parameters:

[0032] Primary fan motor current ≤181A

[0033] Primary fan motor bearing temperature <85℃

[0034] Primary fan bearing temperature < 90°C

[0035] Primary fan coil temperature <110℃

[0036] Hydraulic oil pressure of primary fan ≥2MPa

[0037] Hydraulic oil temperature>15℃

[0038] Primary fan lubrication flow ≥19L / min

[0039] Lubricating oil temperature>10℃

[0040] Primary fan bearing vibration <4mm / s (34.4um)

[0041] Primary fan stall probe differential pressure <0.2KPa

[0042] Hot primary air duct pressure = 10.78KPa

[0043] In a preferred embodiment, electric wind shields 2 are connected to the hot primary air ducts 6 at both ends of the air preheater 4, the hot primary air ducts 6 at the outlet of the primary fan 3, and the hot primary air ducts 6 near the coal mill 1. By controlling multiple electric wind shields 2, multi-section wind pressure control can be achieved when the ventilation volume of the coal mill 1 is constant.

[0044] In a preferred embodiment, a muffler is connected to the inlet end of the primary fan 3 to reduce noise.

[0045] In a preferred embodiment, the cold primary air duct 5 is further provided with a cold air duct 9 with an electric wind shield 2, and the cold air duct 9 is directly connected to the coal mill 1, which can increase the ventilation volume required for carrying and transporting coal powder to a certain extent.

[0046] Finally, it should be noted that the present invention is not limited to the above embodiments, and there are many variations. All variations that can be directly derived or associated with the content disclosed by ordinary technicians in this field should be considered as the protection scope of the present invention.

Claims

1. The primary air whole process adaptive control optimization system is characterized by: The invention comprises a fan system, wherein the fan system comprises a controller, the controller is connected to a primary fan (3), the primary fan (3) is connected to a hot primary air duct (6) with an air preheater (4) through a pipeline, the hot primary air duct (6) between the inlet end of the air preheater (4) and the primary fan (3) is connected to a cold primary air duct (5), the cold primary air duct (5) and the hot primary air duct (6) at the outlet end of the air preheater (4) are connected to a coal mill (1) after being combined, the upper end of the coal mill (1) is connected to two coal mill outlets, and at least one electric wind shield (2) is provided in the hot primary air duct (6) and the cold primary air duct (5) and is communicatively connected to the controller.

2. The primary air full-process adaptive control optimization system according to claim 1 is characterized in that: Flow meters are provided in the hot primary air duct (6) and the cold primary air duct (5).

3. The primary air full process adaptive control optimization system according to claim 2 is characterized in that: The flow meter is communicatively connected to the controller; the flow meter in the cold primary air duct (5) is close to its outlet end, and the flow meter in the hot primary air duct (6) is close to the inlet end of the coal mill (1).

4. The primary air full process adaptive control optimization system according to claim 1, 2 or 3, characterized in that: The primary air fan (3) comprises a primary air fan A and a primary air fan B, the hot primary air duct (6) connected to the primary air fan A is a No. 1 hot primary air duct, the hot primary air duct (6) connected to the primary air fan B is a No. 2 hot primary air duct, and two air supply pipelines (7) are connected between the No. 1 hot primary air duct and the No. 2 hot primary air duct.

5. The primary air full-process adaptive control optimization system according to claim 4 is characterized in that: The two ends of one air supply pipeline (7) are respectively connected to the outlet end of an air preheater (4), and the two ends of another air supply pipeline (7) are respectively connected to the outlet ends of a primary fan A and a primary fan B.

6. The primary air full-process adaptive control optimization system according to claim 1 is characterized in that: A sealed air duct (8) is led out from the cold primary air duct (5) to act on the sealed air of the outlet gate of the coal mill (1) to prevent coal powder from spraying out and polluting the environment.

7. The primary air full-process adaptive control optimization system according to claim 1 is characterized in that: The primary fan (3) is an axial flow fan with adjustable blades, which is provided with a hydraulic control oil system, which includes a hydraulic oil return pipe and two hydraulic control oil pumps, and a cooler is provided on the hydraulic oil return pipe to cool the hydraulic oil return oil with closed cooling water.

8. The primary air full-process adaptive control optimization system according to claim 1 is characterized in that: Electric wind shields (2) are connected to the hot primary air ducts (6) at both ends of the air preheater (4), the hot primary air ducts (6) at the outlet of the primary fan (3), and the hot primary air ducts (6) near the coal mill (1).

9. The primary air full-process adaptive control optimization system according to claim 1 is characterized in that: The inlet end of the primary fan (3) is connected to a silencer.

10. The primary air full process adaptive control optimization system according to claim 8, characterized in that: The cold primary air duct (5) is also provided with a cold air duct (9) with an electric wind shield (2), and the cold air duct (9) is directly connected to the coal mill (1).

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