CN108035905A - A kind of automatic frequency-conversion control system for preventing wind turbine surge - Google Patents

Abstract

The invention discloses an automatic frequency conversion control system for preventing fan surge, which comprises an inlet valve, a fan and a first muffler which are sequentially connected through pipelines, the fan is driven by a motor, the motor is controlled by a frequency converter, and the front-end pipeline of the fan passes through the pipeline The vent valve and the second muffler are connected in sequence, the front end pipe of the fan is provided with a temperature sensor, the front end pipe of the inlet valve is connected with a stop valve and the first pressure transmitter in sequence, and the rear end pipe of the fan is connected through a pipe The second pressure transmitter is connected, the temperature sensor, the first pressure transmitter, the second pressure transmitter, the vent valve and the frequency converter are all electrically connected to a controller, the first pressure transmitter and the second pressure transmitter The transmitter monitors the pressure at the front end of the inlet valve and the rear end of the fan respectively, and transmits the pressure data to the controller. The invention has simple structure and precise control, can effectively avoid fan surge and prolong the service life of the fan.

Description

An Automatic Frequency Conversion Control System to Prevent Fan Surge

technical field

The invention relates to an automatic frequency conversion control system for preventing fan surge.

Background technique

Industrial vacuum cleaner is a kind of matching or cleaning equipment commonly used in industry. It can be used for waste collection, air filtration and purification and environmental cleaning in the process of industrial production. At the same time, it can be used in conjunction with industrial production equipment to absorb dust and debris generated during production to ensure the cleanliness of the working environment and the health of employees. For example, industrial vacuum cleaners are widely used in the textile and chemical industries, reducing the hazards of some occupational diseases; they can absorb metal debris generated by mechanical processing to prevent damage to machinery and equipment.

The fan is an important part of the industrial vacuum cleaner. When the industrial vacuum cleaner is used in harsh working conditions, the fan is prone to surge, which greatly shortens the service life of the fan.

Contents of the invention

In view of the above problems, the present invention provides an automatic frequency conversion control system for preventing fan surge, thereby effectively solving the problems pointed out in the background technology.

The technical scheme adopted in the present invention is:

An automatic frequency conversion control system for preventing fan surge, including an inlet valve, a fan and a first muffler connected in sequence through pipelines, the fan is driven by a motor, and the motor is controlled by a frequency converter. The front-end pipeline is sequentially connected with a vent valve and a second muffler through pipelines, the front-end pipeline of the fan is provided with a temperature sensor, and the front-end pipeline of the inlet valve is sequentially connected with a shut-off valve and a first pressure transmitter through pipelines, The rear end pipeline of the fan is connected with a shut-off valve and a second pressure transmitter through pipelines, and the temperature sensor, the first pressure transmitter, the second pressure transmitter, the vent valve and the frequency converter are all connected with a The controller is electrically connected, and the first pressure transmitter and the second pressure transmitter respectively monitor the pressure at the front end of the inlet valve and the rear end of the fan, and transmit the pressure data to the controller.

As a preference, the controller calculates the actual surge flow of the fan according to the standard surge flow of the fan, the actual number of revolutions, the standard number of revolutions, the standard operating temperature and the actual operating temperature, and the calculation formula is: The controller calculates the actual flow of the fan according to the standard flow of the fan, the actual number of revolutions and the standard number of revolutions, and the calculation formula is:

Among them, F _X is the actual surge flow of the fan, F _S is the standard surge flow of the fan, S _X is the actual number of revolutions of the fan, S _S is the standard number of revolutions of the fan, T _S is the standard operating temperature of the fan, T _X is the actual working temperature of the fan, F _Y is the actual flow of the fan, F _C is the standard flow of the fan, and the T _X is monitored by the temperature sensor and sent to the controller.

Preferably, the vent valve is an on-off valve, and the vent valve is in a fully open state when the fan is started. After the fan is started for 10-200 seconds, the controller starts to control the vent valve to close the vent valve according to a preset time interval. When the ratio of the actual flow rate to the actual surge flow rate is 0.93-1.15 during the closing process, the controller controls the vent valve to stop closing the valve and gives an alarm, and then the controller controls the vent valve to increase the opening until the alarm is eliminated, and then the controller continues to control The vent valve is closed at preset time intervals until the vent valve is fully closed.

Preferably, the vent valve is a regulating valve, and the vent valve is in a fully open state when the fan is started. After the fan is started for 10-200 seconds, the controller starts to control the vent valve to decrease the offset according to the preset time interval. Close the vent valve, when the ratio of the actual flow rate to the actual surge flow rate is 0.93-1.15 during the closing process, the controller controls the vent valve to stop closing and gives an alarm, then the controller controls the vent valve to increase the opening until the alarm is eliminated, and then The controller continues to control the vent valve to close according to the preset time interval and decreasing offset until the vent valve is fully closed.

The invention has simple structure and precise control, can effectively avoid fan surge and prolong the service life of the fan.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Detailed ways

The present invention will be described in further detail below through specific embodiments and in conjunction with the accompanying drawings.

As shown in Figure 1, an automatic frequency conversion control system for preventing fan surge, the arrows in the figure indicate the flow direction of the air flow, including the inlet valve 1, the fan 2 and the first muffler 3 connected in sequence through the pipeline, the described The fan 2 is driven by a motor 4, and the motor 4 is controlled by a frequency converter 5. The front-end pipeline of the fan 4 is connected with a vent valve 6 and a second muffler 7 in turn through the pipeline, and the front-end pipeline of the fan 4 is provided with There is a temperature sensor 8, the front-end pipeline of the inlet valve 1 is connected with a shut-off valve 9 and a first pressure transmitter 10 through pipelines in turn, and the rear-end pipeline of the fan 2 is connected with a shut-off valve 9 and a second pressure transmitter through a pipeline. The pressure transmitter 11, the temperature sensor 8, the first pressure transmitter 10, the second pressure transmitter 11, the vent valve 6 and the frequency converter 5 are all electrically connected to a controller 12, and the first The pressure transmitter 10 and the second pressure transmitter 11 monitor the pressure at the front end of the inlet valve 1 and the rear end of the fan 2 respectively, and transmit the pressure data to the controller 12 .

The controller 12 calculates the actual surge flow rate of the fan 2 according to the standard surge flow rate, the actual number of revolutions, the standard number of revolutions, the standard operating temperature and the actual operating temperature of the fan 2, and the calculation formula is: The controller 12 calculates the actual flow rate of the fan 2 according to the standard flow rate, the actual number of revolutions and the standard number of revolutions of the fan 2, and the calculation formula is:

Among them, F _X is the actual surge flow of fan 2, F _S is the standard surge flow of fan 2, S _X is the actual number of revolutions of fan 2, S _S is the standard number of revolutions of fan 2, and T _S is the speed of fan 2. Standard working temperature, T _X is the actual working temperature of the fan 2, F _Y is the actual flow of the fan 2, F _C is the standard flow of the fan 2, and the T _X is monitored by the temperature sensor 8 and sent to the controller 12.

The vent valve 6 is an on-off valve, and the vent valve 6 is in a fully open state when the fan 2 is started. After the fan 2 is started for 10-200 seconds, the controller 12 starts to control the vent valve 6 to close the vent valve according to a preset time interval. Valve 6, when the ratio of the actual flow rate to the actual surge flow rate is 0.93-1.15 during the closing process, the controller 12 controls the vent valve 6 to stop closing the valve and alarms, and then the controller 12 controls the vent valve 6 to increase the opening until the alarm Eliminate, and then the controller 12 continues to control the vent valve 6 to close according to the preset time interval until the vent valve 6 is fully closed.

The vent valve 6 is a regulating valve, and the vent valve 6 is in a fully open state when the fan 2 is started. After the fan 2 is started for 10-200 seconds, the controller 12 starts to control the vent valve 6 according to a preset time interval, decreasing The offset closes the vent valve 6. During the closing process, when the ratio of the actual flow rate to the actual surge flow rate is 0.93-1.15, the controller 12 controls the vent valve 6 to stop closing the valve and gives an alarm, and then the controller 12 controls the vent valve 6 again. Increase the opening until the alarm is eliminated, and then the controller 12 continues to control the vent valve 6 to close according to the preset time interval and decrementing offset until the vent valve 6 is fully closed.

Motor overload protection function: The motor signal given by the inverter is 4-20mA, and the current signal enters the controller. When the actual current value reaches 95% of the overload value, the controller will give an over-current alarm. When the actual current value reaches 100% When the overload value is reached, the controller will give an alarm for high current and interlock to stop the motor. In order to avoid overload protection shutdown due to excessive starting current, the interlock bypass time must be set. The time is 10-200 seconds. Current overload protection does not work.

Claims (4)

1. a kind of automatic frequency-conversion control system for preventing wind turbine surge, it is characterised in that enter including what is be sequentially connected by pipeline Mouth valve (1), wind turbine (2) and the first muffler (3), the wind turbine (2) are driven by motor (4), and the motor (4) passes through Frequency converter (5) is controlled, and the front-end pipelines of the wind turbine (4) are connected with blow valve (6) and the second noise reduction in turn by pipeline Device (7), the front-end pipelines of the wind turbine (4) are equipped with temperature sensor (8), pass through on the front-end pipelines of the inlet valve (1) Pipeline is connected with shut-off valve (9) and first pressure transmitter (10) in turn, is connected on the rear end pipeline of the wind turbine (2) by pipeline It is connected to shut-off valve (9) and second pressure transmitter (11), the temperature sensor (8), first pressure transmitter (10), second Pressure transmitter (11), blow valve (6) and frequency converter (5) are electrically connected with a controller (12), the first pressure pick-up Device (10) and second pressure transmitter (11) are respectively monitored the pressure of inlet valve (1) front end and wind turbine (2) rear end, and will Pressure data sends controller (12) to.

2. a kind of automatic frequency-conversion control system for preventing wind turbine surge according to claim 1, it is characterised in that described Controller (12) is according to the standard Surging flow of wind turbine (2), actual revolution, standard revolution, standard operating temperature and real work The actual Surging flow of temperature computation blowing machine (2), calculation formula are：Controller (12) basis Normal flow, actual revolution and the standard revolution of wind turbine (2) calculate the actual flow of wind turbine (2), and calculation formula is：Wherein, F_XFor the actual Surging flow of wind turbine (2), F_SFor the standard Surging flow of wind turbine (2), S_XFor wind The actual revolution of machine (2), S_SFor the standard revolution of wind turbine (2), T_SFor the standard operating temperature of wind turbine (2), T_XFor wind turbine (2) Actual work temperature, F_YFor the actual flow of wind turbine (2), F_CFor the normal flow of wind turbine (2), the T_XBy temperature sensor (8) monitor and be transmitted to controller (12).

3. a kind of automatic frequency-conversion control system for preventing wind turbine surge according to claim 2, it is characterised in that described Blow valve (6) is switch valve, and the blow valve (6) is shown in a fully open operation when wind turbine (2) starts, and wind turbine (2) starts 10-200 After second, controller (12) starts to control blow valve (6) to close blow valve (6) according to default time interval, in closing process When the ratio of actual flow and actual Surging flow is 0.93-1.15, controller (12) control blow valve (6) stops closing valve, and Alarm, then controller (12) controls blow valve (6) to increase aperture again, until alarm eliminates, then controller (12) continues to control Blow valve (6) processed is closed according to default time interval, until blow valve (6) is fully closed.

4. a kind of automatic frequency-conversion control system for preventing wind turbine surge according to claim 2, it is characterised in that described Blow valve (6) is regulating valve, and the blow valve (6) is shown in a fully open operation when wind turbine (2) starts, and wind turbine (2) starts 10-200 After second, controller (12) starts to control blow valve (6) to close blow valve (6) according to default time interval, decremental offset amount, In closing process during the ratio 0.93-1.15 of actual flow and actual Surging flow, controller (12) control blow valve (6) stops Valve is closed, and is alarmed, then controller (12) controls blow valve (6) to increase aperture again, is eliminated until alarming, then controller (12) Continue to control blow valve (6) to be closed according to default time interval, decremental offset amount, until blow valve (6) is fully closed.