TW201827763A - Rotation speed control method of blower of hot-water heater, and hot-water heater having the same - Google Patents

Abstract

A rotation speed control method is for a blower of a hot-water heater. The rotation speed control method comprising: determining a target rotation speed of the blower according to the output of the gas valve; Controlling the level of the PWM signal and sending it to the control board inside the blower according to the target rotation speed of the blower so that the control board changes the three-phase voltage command to adjust the rotation speed of the blower; determining whether the rotation speed of the blower is equal to the target rotation speed of the blower, if it is judged that the rotation speed of the blower is equal to the target rotation speed of the blower, and then making the level of the PWM signal fixed.

Description

 Blower speed control method of hot water device and hot water device thereof  

The invention relates to a method for controlling the speed of a blower of a hot water device and a hot water device thereof, in particular to a method for controlling the speed of a blower that can also control the speed of a blower of a hot water device and a hot water device thereof.

With the advancement of the times, hot water devices have become an indispensable device for the current home life. The energy classification used by hot water devices can be roughly divided into gas water heaters, electric water heaters and solar water heaters. Among them, gas water heaters are the most Common use.

The gas water heater needs to control the speed of its blower to change the air volume, thus obtaining different air quantities. This is because the gas water heater needs to have a good ratio of air to gas when it is in a burning state. When gas and air have a good ratio, it can get better combustion efficiency and lower exhaust gas. If the gas is not well matched with air, red fire, flying fire, vibration and flameout may occur, resulting in excessive exhaust gas. Insufficient burning and other hazards that are harmful to health and safety.

Gas turbine water heaters are most commonly used with BLDC DC brushless motors. The BLDC blower can be divided into two types of high voltage and low voltage for the voltage VM for control, and it can be divided into two types: control board built-in and external control. Gas-fired water heaters that use BLDC blowers on the market generally use low-voltage and control-board built-in models. Referring to FIG. 1 to FIG. 5, FIG. 1 and FIG. 2 illustrate a rectifying and filtering circuit 1A of a gas water heater and a control side circuit 2A for generating a rotational speed control voltage VM. FIG. 3 exemplifies a control substrate circuit 3A built into a blower of a gas water heater and The motor M, and FIG. 4 exemplifies a detailed circuit diagram of the drive circuit 31A and the motor M that control the substrate circuit 3A. The gas water heater can calculate the target rotational speed of the blower according to the output of the gas valve (ie, the opening degree of the gas valve), and then generate a pulse width modulation signal FanPWM through the temperature controller according to the target rotational speed to control the pulse width modulation signal. The output of the FanPWM (ie, the duty ratio) changes the conduction period of the switching element MS2 to control the on and off of the switching element MD1 to change the voltage VM value, and sends it to the driving circuit 31A of the built-in control substrate circuit 3A of the blower (as shown in the figure). 3, 4), whereby the rotational speed of the motor M during operation is changed according to the voltage VM value. When the voltage VM is larger, the rotational speed rpm is higher (as shown in FIG. 5).

However, the circuit between the voltage VF and the voltage VM (the control side circuit 2A) includes a plurality of passive components in addition to the switching element MS2, which causes a significant increase in the cost of the water heater. Therefore, how to save the use of the above external components and achieve the speed control is an object of the present inventors. The present inventors have been engaged in the development and design of related products for many years, and have felt that the lack of improvement over the years can be improved. With great interest in research and the use of academics, the present invention finally proposes a present invention which is reasonable in design and effective in improving the above-mentioned defects.

The object of the present invention is to provide a method for controlling the speed of a blower of a hot water device and a hot water device thereof, which can save external components and achieve speed control, thereby effectively reducing the complexity of design and the man-hour and cost of manufacturing.

In order to achieve the above, the present invention provides a blower speed control method for a hot water device, which is suitable for a hot water device, which includes a gas valve, a main control unit and a blower with a control substrate circuit built therein. The gas valve and the blower are respectively coupled to the main control unit, and the blower speed control method comprises: calculating a target rotational speed of the blower according to the output of the gas valve; controlling the output of the main control unit according to the target rotational speed of the blower The output of the pulse width modulation signal is sent to the built-in control substrate circuit of the blower, so that the control substrate circuit changes the three-phase voltage command according to the output of the pulse width modulation signal to change the rotation speed of the blower; Whether the rotational speed reaches the target rotational speed of the blower; and if it is determined that the target rotational speed of the blower is reached, the output of the pulse width modulation signal is fixed.

In order to achieve the above, the present invention provides a hot water device, which is provided with: a gas valve, a main control unit and a blower with a control substrate circuit, the gas valve and the blower are respectively coupled to the main control a unit, wherein the main control unit is configured to calculate a target rotational speed of the blower according to the output of the gas valve, and control the output of the pulse width modulation signal according to the target rotational speed of the blower and send the control to the built-in control of the blower The substrate circuit causes the control substrate circuit to change the three-phase voltage command according to the output of the pulse width modulation signal to change the rotation speed of the blower.

As described above, according to the blower speed control method and the hot water apparatus of the hot water apparatus of the present invention, the use of external components can be saved and the effect of the rotational speed control can be achieved, and the design complexity and the man-hour and cost of manufacture can be effectively reduced.

 [Prior technology]  

1A‧‧‧Rectifier filter circuit

2A‧‧‧Control side circuit

3A‧‧‧Control substrate circuit

31A‧‧‧Drive Circuit

MS2, MD1‧‧‧ switching components

FanPWM‧‧‧ pulse width modulation signal

VF, VM‧‧‧ voltage

M‧‧ motor

Rpm‧‧‧speed

 [this invention]  

H‧‧‧Water heater

H1‧‧‧ body

10‧‧‧ gas valve

20‧‧‧Master unit

30‧‧‧Air blower

40‧‧‧burner

50‧‧‧ heat exchanger

31‧‧‧Control substrate circuit

311‧‧‧Microprocessor

312‧‧‧ drive

313‧‧‧ drive circuit

314‧‧‧Hor sensor

VM‧‧‧ voltage

FanPWM‧‧‧ pulse width modulation signal

M‧‧ motor

W, V, U‧‧‧ coil

Rpm‧‧‧speed

Tr1~Tr6‧‧‧Switching elements

C‧‧‧Three-phase voltage command

S‧‧‧ position sensing signal

1‧‧‧Rectifier filter circuit

S201~S207‧‧‧Steps

Figure 1 is a schematic diagram of a prior art circuit.

2 is a schematic view of the detailed circuit of FIG. 1.

3 is a circuit diagram of a prior art blower.

4 is a schematic view of the detailed circuit of FIG. 3.

Figure 5 is a schematic diagram showing the relationship between voltage and speed of the prior art.

Figure 6 is a schematic view of a hot water device of the present invention.

Figure 7 is a schematic diagram of the circuit of the present invention.

Figure 8 is a circuit diagram of the blower of the present invention.

Figure 9 is a schematic view of the detailed circuit of Figure 8.

FIG. 10 is a schematic diagram showing the relationship between the pulse width modulation signal and the rotational speed of the present invention.

Figure 11 is a flow chart of the present invention.

The following is a specific embodiment to explain the embodiment of the present invention relating to "the method of controlling the blower speed of a hot water device and its hot water device", and those skilled in the art can easily understand the contents disclosed in the present specification. Advantages and effects of the present invention. The present invention may be carried out or applied in various other specific embodiments, and various modifications and changes can be made without departing from the spirit and scope of the invention. In addition, the drawings of the present invention are merely illustrative and are not intended to be construed in terms of actual dimensions. The following embodiments will further explain the related technical content of the present invention, but the disclosure is not intended to limit the technical scope of the present invention.

Referring to FIG. 6 to FIG. 10, an embodiment of the present invention provides a hot water device H. The hot water device H of the embodiment is a gas water heater, and a gas valve 10, a main control unit 20 and a blower 30 having a control substrate circuit 31 built therein are disposed in the body H1 of the hot water device H, and the gas valve 10, The positions at which the main control unit 20 and the blower 30 are disposed are not limited and may be changed as needed. In addition, the hot water device H further includes various components and related circuits required for the operation of the general hot water device such as the burner 40 and the heat exchanger 50. These components and related circuits are not technical features of the present invention, and therefore will not be described again.

The gas valve 10 and the blower 30 can be controlled by the main control unit 20 to vary the flow rate of gas supplied to the burner 40 and to vary the amount of air supplied to the burner 40 to obtain a good air to gas ratio. In detail, the main control unit 20 can be, for example, any unit, device or module that can be used to generate the pulse width modulation signal FanPWM, such as a thermostat, a PID controller or a signal generator. Moreover, the main control unit 20 can calculate the target rotational speed of the blower 30 according to the output of the gas valve 10 (ie, the opening degree of the gas valve 10 or the gas flow rate), and perform PID control according to the target rotational speed of the blower 30 to control the output pulse. The output of the width modulation signal FanPWM (ie, the duty ratio), that is, when the output of the pulse width modulation signal FanPWM is half, the duty ratio is 50%, and when the output of the pulse width modulation signal FanPWM is four points In one of them, the duty ratio is 25%. Moreover, an external power source (such as an AC power source or a commercial power source) can be sent to the control board circuit 31 built in the blower 30 via the rectifier filter circuit 1 (see FIGS. 7 and 8). Therefore, in this embodiment, the voltage VM is fixed. It is not necessary to set the control side circuit 2A as shown in Figs. 1 and 2 to change its voltage value. The rectifying and filtering circuit 1 can be identical to the rectifying and filtering circuit 1A shown in FIG.

Specifically, as shown in FIG. 9, the blower 30 has a motor M therein, which may be a three-phase motor, and is provided with a coil W (W phase coil), a coil V (V phase coil), and a coil U (U phase coil). The control substrate circuit 31 is coupled to the motor M, and the control substrate circuit 31 includes a microprocessor 311, a driver 312, a driving circuit 313, and a Hall sensor 314. The driver 312 and the Hall sensor 314 are respectively coupled to The microprocessor 311 is coupled between the driver 312 and the motor M, and the Hall sensor 314 is mounted on the rotor of the motor M. The driving circuit 313 is controlled by the driver 312 for controlling to supply a driving current to the motor M to drive the motor M, and the driver 312 is controlled by the microprocessor 311 for controlling and controlling the action of the driving circuit 313. The switching elements of the driving circuit 313 are selectively turned on and the input voltage is changed. More specifically, the driving circuit 313 can be divided into two groups of upper and lower arms by using six switching elements Tr1 to Tr6, such as MOSFETs, the upper arms are Tr1, Tr2, and Tr3, and the lower arms are Th4, Th5, and Th6, and the six switches are The components Th1~Th6 can be selectively turned on to make the power supply on the U, V and W phase coils forward and reverse. For example, when Tr3 and Tr5 are turned on, the current will flow from the U phase of the motor M, and the V phase will flow out, resulting in U+. The power direction input of V-, which can be switched in sequence, can be simulated as a three-phase power input, so that the motor M continues to run. When the motor M is in operation, the microprocessor 311 can receive the position sensing signal S via the Hall sensor 314 to know the position of the rotor of the motor M, and can adjust the output of the signal FanPWM according to the received pulse width. The three-phase voltage command C outputted to the driver 312 is changed to pass through the pulse width modulation switching control technology of the driver 312, and the switching elements Tr1 to Tr6 are selectively turned on and the voltages output to the switching elements Tr1 to Tr6 are controlled to be controlled. The speed of the motor M. Therefore, the control substrate circuit 31 built in the blower 30 can directly change the rotation speed according to the output of the pulse width modulation signal FanPWM. When the output of the FanPWM is higher, the rotation speed rpm is higher (see FIG. 10). Thereby, the control side circuit 2A shown in FIG. 2 can be completely omitted, and the cost can be greatly reduced and the speed control can be achieved.

Please refer to FIG. 11 and please refer to FIG. 6 to FIG. 10 as appropriate. The embodiment of the invention provides a method for controlling the speed of the blower of the hot water device, which is suitable for the hot water device H. The hot water device H includes a gas valve 10, a main control unit 20, and a blower 30 having a control substrate circuit. The gas valve 10 and the blower 30 are respectively coupled to the main control unit 20. The blower speed control method includes:

In step S201, the target rotational speed of the blower 30 is calculated in accordance with the output of the gas valve 10. In practice, when the user opens the faucet or the shower head, the hot water device H starts to operate, the gas valve 10 is opened, and the blower 30 is operated, and can be passed through the main control unit 20 (such as a thermostat) according to the gas valve 10 The output (i.e., the degree of opening of the gas valve 10 or the gas flow rate) calculates the target rotational speed of the blower 30.

Next, in step S203, the output of the pulse width modulation signal FanPWM that is controlled to be output is output according to the target rotational speed of the blower 30, and sent to the control substrate circuit 31 built in the blower 30, so that the control substrate circuit 31 adjusts the signal according to the pulse width. The output of the FanPWM changes the three-phase voltage command C to change the rotational speed of the blower 30. In practice, the PID control (Proportional integral differential control) can be performed through the main control unit 20, that is, after the target speed is subtracted from the actual speed of the feedback, the deviation signal is used as an input signal to perform a PID operation to calculate the final control amount. The output of the pulse is modulated by the pulse width of the control output (ie, the duty cycle).

Then, in step S205, it is determined whether or not the rotational speed of the blower 30 reaches the target rotational speed of the blower 30.

If the decision result in the step S205 is NO, the flow returns to the step S203. If the answer of step S205 is YES, the process proceeds to step S207 to fix the output of the pulse width modulation signal FanPWM.

By using the output of the modified or fixed pulse width modulation signal FanPWM to inform the blower built-in control substrate circuit, the built-in control substrate circuit of the blower can change or fix the speed of the blower according to the pulse width modulation signal FanPWM, so that The control side circuit shown in Figures 1 and 2 can be completely omitted, so that the cost of the hot water device can be greatly reduced and the speed control can be achieved.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of the invention.

Claims (6)

 The utility model relates to a blower speed control method for a hot water device, which is suitable for a hot water device, which comprises a gas valve, a main control unit and a blower with a control substrate circuit built therein, wherein the gas valve and the blower are respectively coupled In the main control unit, the blower speed control method comprises: calculating a target rotational speed of the blower according to the output of the gas valve; and controlling the output of the pulse width modulation signal output by the main control unit according to the target rotational speed of the blower; The control substrate circuit built into the blower is configured to change the three-phase voltage command according to the output of the pulse width modulation signal to change the rotational speed of the blower; and determine whether the rotational speed of the blower reaches the target rotational speed of the blower; And if it is determined that the target rotational speed of the air blower is reached, the output of the pulse width modulation signal is fixed.    The method for controlling a blower speed of a hot water device according to claim 1, wherein the control substrate circuit comprises a microprocessor, a driver, a driving circuit, and a Hall sensor, and the driver and the Hall sensor are respectively coupled In the microprocessor, the driving circuit is coupled between the driver and the motor of the blower, and the driver selectively turns on and drives the driving circuit according to the three-phase voltage command output by the microprocessor. The input voltage value of the circuit changes.    The method for controlling a blower speed of a hot water device according to claim 2, wherein the drive circuit comprises six switching elements that are selectively turned on by the driver.    A hot water device is provided with: a gas valve, a main control unit and a blower with a control substrate circuit, the gas valve and the blower are respectively coupled to the main control unit, and the main control unit is used for The output of the gas valve calculates the target rotational speed of the blower, and outputs the output of the pulse width modulation signal according to the target rotational speed of the blower to the built-in control substrate circuit of the blower, so that the control substrate circuit is The output of the pulse width modulation signal changes the three-phase voltage command to change the speed of the blower.    The hot water device of claim 4, wherein the control substrate circuit comprises a microprocessor, a driver, a driving circuit and a Hall sensor, and the driver and the Hall sensor are respectively coupled to the microprocessor The driving circuit is coupled between the driver and the motor of the blower, and the driver selectively turns on the driving circuit according to the three-phase voltage command output by the microprocessor and causes an input voltage value of the driving circuit change.    The hot water device of claim 5, wherein the driving circuit comprises six switching elements that are selectively turned on by the driver.