INDUCED DRAFT FAN

Abstract

An induced draft fan, including: a fan housing, a wind wheel, and an ECM motor including a motor body and a motor controller. The motor controller is a control board that is not enclosed in a control box. The control board includes a microprocessor unit, an IGBT switch and a drive unit thereof, a detection unit for detecting operating parameters of the motor, and a DIP switch unit. The detection unit transmits operating parameters of the motor to the microprocessor unit. The microprocessor unit outputs a signal to control the IGBT switch and the drive unit thereof. An output end of the IGBT switch and the drive unit thereof is connected to the coil winding of the stator. An output end of the DIP switch unit is connected to an input end of the microprocessor unit.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an induced draft fan.

2. Description of the Related Art

A typical induced draft fan, as shown in FIG. 1, is generally driven by a single phase motor PSC, and the single phase motor PSC is controlled by a system controller via a plurality of gear switch signals output therefrom. However, the single phase AC motor has low efficiency, relatively high energy consumption, large noise, and low controllability. The technical scheme has poor compatibility, and different application loads demand different compatible motors, thereby resulting in long development cycle, high management costs, poor versatility, and inconvenience in use.

An electronically commutated motor (ECM motor), including a DC brushless motor, a switched reluctance motor, and PMSM, is advantageous in energy saving, intelligence, high stability and controllability, and small noise. It is capable of regulating the output torque and the air volume, thereby shortening the development time and saving the development costs.

Although the ECM motors have been utilized in the induced draft fan, it is troublesome to regulate the output power, the rotation torque, the rotational speed, and the air volume of the ECM motor, which demands either rewriting the control program of the motor by professional programmers or replacing the motor, thereby being very inconvenient.

SUMMARY OF THE INVENTION

In view of the above-described problems, it is one objective of the invention to provide an induced draft fan that adopts an energy-saving ECM motor to substitute for the conventional single phase AC motor PSC and that is convenient for the user to regulate the operating parameters of the motor.

To achieve the above objective, in accordance with one embodiment of the invention, there is provided an induced draft fan, comprising: a fan housing, the fan housing comprising a surface; a wind wheel; and an ECM motor, the ECM motor comprising a motor body and a motor controller. The motor body comprises: a stator, a rotor, and a casing. The stator comprises a coil winding. The rotor comprises a rotor shaft comprising an end. The motor controller is a control board that is not enclosed in a control box (control box-free control board). The control board comprises: a microprocessor unit comprising an input end, an IGBT switch and a drive unit thereof comprising an output end, a detection unit for detecting operating parameters of the motor, and a DIP switch unit comprising an output end. The wind wheel is disposed inside the fan housing. The ECM motor is disposed on the surface of the fan housing. The end of the rotor shaft of the rotor protrudes inside the fan housing and is connected to the wind wheel. The motor body is connected to the motor controller via an electric wire. The detection unit transmits operating parameters of the motor to the microprocessor unit. The microprocessor unit outputs a signal to control the IGBT switch and the drive unit thereof. The output end of the IGBT switch and the drive unit thereof is connected to the coil winding of the stator. The output end of the DIP switch unit is connected to the input end of the microprocessor unit.

In a class of this embodiment, the DIP switch unit comprises a plurality of independent DIP switches.

In a class of this embodiment, a number of the DIP switches is between seven and twelve.

In a class of this embodiment, the microprocessor unit reads a signal of each DIP switch of the DIP switch unit to form a code set, selects parameters of a rotational speed, a torque, and an air volume, and outputs a signal to control the IGBT switch and the drive unit thereof.

In a class of this embodiment, the control board further comprises a gear switch detection circuit. The gear switch detection circuit detects a plurality of gear switch signals output by a system controller and transmits the gear switch signals to the microprocessor. The microprocessor outputs a signal to control the IGBT switch and the drive unit thereof according to the gear switch signals.

In a class of this embodiment, the gear switch detection circuit comprises a plurality of optical coupling isolation circuits.

In a class of this embodiment, the microprocessor unit is connected to a communication port. The microprocessor unit communicates with a PC computer via the communication port. The PC computer sets or modifies the operating parameters of the motor in the microprocessor by programming.

Advantages according to embodiments of the invention are summarized as follows:

1) The motor controller herein is a control board that is not enclosed in a control box. The control board is provided with the microprocessor unit, the IGBT switch and the drive unit thereof, and the detection unit for detecting operating parameters of the motor. The control board is further provided with the DIP switch unit, the output end of which is connected to the input end of the microprocessor unit. The microprocessor unit reads information of each DIP switch of the DIP switch unit to form the code set, selects parameters of the rotational speed, the torque, and the air volume, and outputs signals to control the IGBT switch and the drive unit thereof. Thus, persons skilled in the art are not required to know how to program, they can set the coding of the DIP switch unit by utilizing the operation book to regulate the parameters of the rotational speed, the torque, and the air volume of the induced draft fan and the operation mode thereof, thereby being simple and convenient to meet the demands of the user.

2) The DIP switch unit comprises a plurality of independent DIP switches. The number of the DIP switches is between seven and fifteen, so that relatively broad information is obtained from the code sets, thereby meeting the demands of the user.

3) The control board is further provided with the gear switch detection circuit that detects the gear switch signals of the system controller and sends them to the microprocessor unit. The microprocessor unit outputs the signal to control the IGBT switch and the drive unit thereof according to the gear switch signals, and is capable of communicating with the system controller and broadening the application range thereof.

4) The microprocessor unit is connected to the communication port. The microprocessor unit communicates with the PC computer via the communication port. The PC computer sets or regulates the operating parameters of the motor in the microprocessor unit by programming, thereby being convenient for debugging the induced draft fan.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described hereinbelow with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a conventional induced draft fan;

FIG. 2 is a structure diagram of an induced draft fan according to one embodiment of the invention;

FIG. 3 is a cross sectional view of an induced draft fan according to one embodiment of the invention;

FIG. 4 is a schematic diagram of an induced draft fan according to one embodiment of the invention; and

FIG. 5 is a specific circuit block diagram of FIG. 4.

DETAILED DESCRIPTION OF THE EMBODIMENTS

For further illustrating the invention, experiments detailing an induced draft fan are described below. It should be noted that the following examples are intended to describe and not to limit the invention.

As shown in FIGS. 2-5, an induced draft fan comprises: a fan housing 1, a wind wheel 2 disposed inside the fan housing 1, and an ECM motor disposed on a surface of the fan housing 1. The ECM motor comprises a motor body 3 and a motor controller. The motor body comprises: a stator 31, a rotor 32, and a casing 33. An end 320 of a rotor shaft of the rotor 32 protrudes inside the fan housing 1 and is connected to the wind wheel 2. The motor body is connected to the motor controller via an electric wire 5. The motor controller is a control board 4 that is not enclosed in a control box. The control board 4 comprises: a microprocessor unit, an IGBT switch and a drive unit thereof, and a detection unit for detecting operation parameters of the motor. The detection unit transmits the operating parameters of the motor to the microprocessor unit, and the microprocessor unit outputs a signal to control the IGBT switch and the drive unit thereof. An output end of the IGBT switch and the drive unit thereof is connected to a coil winding of the stator. The control board 4 is further provided with a DIP switch unit 6. An output end of the DIP switch unit 6 is connected to an input end of the microprocessor unit. The DIP switch unit 6 comprises a plurality of DIP switches, and a number of the DIP switches is between seven and fifteen. The microprocessor unit reads a signal of each DIP switch of the DIP switch unit to form a code set, selects parameters of a rotational speed, a torque, and an air volume, and outputs a signal to control the IGBT switch and the drive unit thereof. The microprocessor unit is a micro controller unit (MCU) or a digital signal processor (DSP). The control board 4 further comprises a gear switch detection circuit. The gear switch detection circuit detects a plurality of gear switch signals output by a system controller and sends the gear switch signals to the microprocessor. The microprocessor outputs a signal according to the gear switch signal to control the IGBT switch and the drive unit thereof. The gear switch detection circuit comprises a plurality of optical coupling isolation circuits.

The microprocessor unit is connected to a communication port. The microprocessor unit communicates with a PC computer via the communication port. The PC computer sets or modifies the operating parameters of the motor in the microprocessor unit by programming.

Thus, persons skilled in the art are not required to know how to program, they can set the coding of the DIP switch unit by utilizing the operation book to regulate the parameters including the rotational speed, the torque, and the air volume of the induced draft fan and the operation mode thereof, thereby being simple and convenient to meet the demands of the user. Definitions of different code sets of the DIP switch unit are all recorded on the operation book, so that it is convenient for the persons skilled in the art to directly set the operating mode and parameters of the induced draft fan according to actual operating environment.

EXAMPLE 1

The DIP switch unit 6 comprises nine DIP switches. When the coding of the nine DIP switches is 001001111, the microprocessor unit reads the information of each DIP switch of the DIP switch unit. The coding 001001111 means that the motor operates at a constant rotational speed of 1000 rpm. The microprocessor outputs a corresponding signal to control the IGBT switch and the drive unit thereof.

EXAMPLE 2

The DIP switch unit 6 comprises nine DIP switches. When the coding of the nine DIP switches is 101011100, the microprocessor unit reads the information of each DIP switch of the DIP switch unit. The coding 101011100 means that the motor operates at a constant torque of 400 N.m. The microprocessor outputs a corresponding signal to control the IGBT switch and the drive unit thereof.

EXAMPLE 3

The DIP switch unit 6 comprises nine DIP switches. When the coding of the nine DIP switches is 110011001, the microprocessor unit reads the information of each DIP switch of the DIP switch unit. The coding 110011001 means that the motor operates at a constant air volume. A torque is 600 N m, and a rotational speed is 800 rpm. The microprocessor outputs a corresponding signal to control the IGBT switch and the drive unit thereof.

While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.

Claims

1. An induced draft fan, comprising: a) a fan housing, the fan housing comprising a surface;b) a wind wheel; andc) an ECM motor, the ECM motor comprising a motor body and a motor controller; the motor body comprising: a stator, a rotor, and a casing; the stator comprising a coil winding; the rotor comprising a rotor shaft comprising an end;the motor controller being a control board that is not enclosed in a control box; the control board comprising: a microprocessor unit comprising an input end, an IGBT switch and a drive unit thereof comprising an output end, a detection unit for detecting operating parameters of the motor, and a DIP switch unit comprising an output end;

2. The induced draft fan of claim 1, wherein the DIP switch unit comprises a plurality of independent DIP switches.

3. The induced draft fan of claim 1, wherein a number of the DIP switches is between seven and twelve.

4. The induced draft fan of claim 1, wherein the microprocessor unit reads a signal of each DIP switch of the DIP switch unit to form a code set, selects parameters of a rotational speed, a torque, and an air volume, and outputs a signal to control the IGBT switch and the drive unit thereof.

5. The induced draft fan of claim 1, wherein the control board further comprises a gear switch detection circuit;the gear switch detection circuit detects a plurality of gear switch signals output by a system controller and transmits the gear switch signals to the microprocessor; andthe microprocessor outputs a signal to control the IGBT switch and the drive unit thereof according to the gear switch signals.

6. The induced draft fan of claim 2, wherein the control board further comprises a gear switch detection circuit;the gear switch detection circuit detects a plurality of gear switch signals output by a system controller and transmits the gear switch signals to the microprocessor; andthe microprocessor outputs a signal to control the IGBT switch and the drive unit thereof according to the gear switch signals.

7. The induced draft fan of claim 3, wherein the control board further comprises a gear switch detection circuit;the gear switch detection circuit detects a plurality of gear switch signals output by a system controller and transmits the gear switch signals to the microprocessor; andthe microprocessor outputs a signal to control the IGBT switch and the drive unit thereof according to the gear switch signals.

8. The induced draft fan of claim 4, wherein the control board further comprises a gear switch detection circuit;the gear switch detection circuit detects a plurality of gear switch signals output by a system controller and transmits the gear switch signals to the microprocessor; andthe microprocessor outputs a signal to control the IGBT switch and the drive unit thereof according to the gear switch signals.

9. The induced draft fan of claim 5, wherein the gear switch detection circuit comprises a plurality of optical coupling isolation circuits.

10. The induced draft fan of claim 6, wherein the gear switch detection circuit comprises a plurality of optical coupling isolation circuits.

11. The induced draft fan of claim 7, wherein the gear switch detection circuit comprises a plurality of optical coupling isolation circuits.

12. The induced draft fan of claim 8, wherein the gear switch detection circuit comprises a plurality of optical coupling isolation circuits.

13. The induced draft fan of claim 5, wherein the microprocessor unit is connected to a communication port;the microprocessor unit communicates with a PC computer via the communication port; andthe PC computer sets or modifies the operating parameters of the motor in the microprocessor by programming

14. The induced draft fan of claim 6, wherein the microprocessor unit is connected to a communication port;the microprocessor unit communicates with a PC computer via the communication port; andthe PC computer sets or modifies the operating parameters of the motor in the microprocessor by programming.

15. The induced draft fan of claim 7, wherein the microprocessor unit is connected to a communication port;the microprocessor unit communicates with a PC computer via the communication port; andthe PC computer sets or modifies the operating parameters of the motor in the microprocessor by programming.

16. The induced draft fan of claim 8, wherein the microprocessor unit is connected to a communication port;the microprocessor unit communicates with a PC computer via the communication port; andthe PC computer sets or modifies the operating parameters of the motor in the microprocessor by programming.