JPH06117625A - Fan control method for burner and fan for burner - Google Patents

Abstract

PURPOSE:To secure an appropriate amount of air to be supplied and extend the range of hot water supply capacity of a hot water supply heater in view of combustion performance by using a load monitor means in order to determine the amount of load applied to a fan. CONSTITUTION:When external turbulence is applied to voltage control, for example, when air blows into an exhaust air port, a combustion operating point A moves to a point B. As a result, the air capacity is reduced from QA to QB while the rotary speed is increased from NA to NB. At that time, a load monitor means 17 determines the amount of load to a fan 6 based on a pulse signal 16 and applied voltage of the fan 6. A fan control means 14 corrects the applied voltage to the fan 6 to a value equivalent to the amount of the load based on the load thus determined. This constitution makes it possible to secure a proper amount of air in terms of combustion performance since the air capacity is recovers from QB to QA.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blower control method and apparatus used for combustion equipment such as a gas water heater.

[0002]

2. Description of the Related Art FIG. 2 shows a front view of a conventional water heater, and FIG. 3 shows a side view thereof. As shown therein, the water heater comprises a plurality of burners 1, a burner chamber 2 for housing the burners 1, a combustion chamber 3, a heat exchange chamber 4, an exhaust chamber 5, and a blower 6. The fuel gas 7 passes through the fuel flow rate control valve 8, is guided to the manifold 9, and is injected into each burner 1. The fuel air 10 is supplied by the blower 6, and a flame is formed in the burner 1 to completely burn it. The high temperature combustion gas 11 generated by combustion enters the heat exchanger 4 and heats the water 12.
The combustion gas 11 having the lowered temperature becomes the exhaust gas 13 and is discharged from the exhaust chamber 5 to the outside. Conventionally, each control voltage applied to the blower 6 and the fuel flow rate control valve 8 is determined to have a predetermined value from the maximum to the minimum according to the combustion amount, as shown in FIG. The blower 6 has been subjected to voltage control to keep the applied voltage constant and rotation speed control to keep the rotation speed constant.

[0003]

However, in the voltage control and the rotation speed control as described above, in the characteristic diagram showing the relationship between the blower air volume Q and the discharge pressure P and the rotation speed N as shown in FIG. There was such a problem. In voltage control, the combustion operating point A moves to B in the case of a disturbance in which wind pressure is applied to the exhaust port, and the air volume decreases from QA to QB, so the combustion performance deteriorates. Further, since the rotation speed increases from NA to NB, in the rotation speed control, the blower applied voltage is reduced from V ₁ to V ₂ in order to return the rotation speed from NB to NC, so that the P-Q characteristic is P (V ₁ ) To P (V ₂ ). As a result, the QC is further reduced, and the combustion performance is further deteriorated.

[0004]

According to the present invention, there is provided a blower for guiding combustion air to a burner, and a blower control means for applying a voltage to the blower so as to control the blower according to a required combustion air amount at that time. With a load amount monitoring means for obtaining a load amount applied to the blower from a pulse signal proportional to the number of rotations generated from the blower and a voltage applied to the blower, the voltage applied to the blower corresponds to the load amount. It has a control means for correcting the value to

[0005]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a blower control system according to an embodiment of the present invention. 6 is a blower, 14 is a blower control means including a DC power source, 15 is a voltage applied to the blower 6, 16 is a pulse signal generated by the blower 6 in proportion to the rotation speed, and 17 is a load amount applied to the blower 6. It is a load amount monitoring means. Since the load amount is uniquely determined by the blower rotation speed and the applied voltage, the load amount monitoring means 17 causes the pulse signal 16 (P
L) and the applied voltage (VF) to the blower 6, the load amount (W) on the blower 6 is obtained by a function W = f (PL, VF) predetermined by experiments or the like. Next, FIG. 5 shows a characteristic diagram of the air volume (Q) from the blower, the discharge pressure (P), and the rotation speed (N). Hereinafter, the operation of the present invention will be described with reference to FIG. In the case of voltage control, when a disturbance such as blowing of air into the exhaust port 5 is applied, the combustion operating point A moves to B, so the air volume decreases from QA to QB and the rotation speed increases from NA to NB. At this time, the load monitoring means 17 determines that the function W = f.
The load amount (W) is calculated from (PL, VF). The blower control means 14 receives it, and the applied voltage V to the blower 6 is V.
_By correcting 1 to a value V ₃ which also corresponds to W experimentally obtained and applying V ₃ to the blower 6, the rotation speed is increased from NB to ND and the air volume is recovered from QB to QA. Therefore, it is possible to secure an appropriate air volume in terms of combustion performance. Although the voltage control has been described in the present embodiment as well, the function W = f (P
Similar effects can be obtained by determining L, VF) by experiments or the like.

[0006]

According to the present invention, as a method for controlling a blower, a load amount monitoring means for determining a load amount applied to the blower is used to correct the voltage applied to the blower, which is suitable for combustion performance. It is possible to secure a sufficient amount of air from a blower. That is, it is possible to expand the hot water supply capacity range of the water heater and improve the usability.

[Brief description of drawings]

FIG. 1 is a block diagram of a blower control method according to an embodiment of the present invention.

FIG. 2 is a front view showing a water heater used in an embodiment of the present invention.

FIG. 3 is a side view showing a water heater used in an embodiment of the present invention.

FIG. 4 is a diagram showing a relationship between an air volume from a blower of a conventional example, a discharge pressure, and a rotation speed, for explaining conventional control.

FIG. 5 is a diagram showing the relationship between the air flow rate from the blower of one embodiment of the present invention, the discharge pressure, and the rotation speed.

FIG. 6 is a diagram showing a relationship between a combustion amount, an opening of a fuel flow rate control valve, and a blower control voltage in a conventional example.

[Explanation of symbols]

1. Burner 2. Burner room 3. Combustion chamber 4. Heat exchanger 5. Exhaust chamber 6. Blower 7. Fuel gas 8. Fuel flow control valve 9. Manifold 10. Fuel air 11. Fuel gas 12. Water 13. Exhaust gas 14. Blower control means 15. Applied voltage 16. Pulse signal 17. Load monitoring means

Claims (2)

[Claims] 1. A blower for guiding combustion air to a burner, and a method for controlling a blower for a combustion device in which a voltage is applied to the blower so as to control the blower in accordance with a required air volume for combustion at that time, a rotation generated from the blower. A blower characterized by obtaining a load amount applied to the blower from a pulse signal proportional to the number and a voltage applied to the blower, and correcting the voltage applied to the blower to a value corresponding to the load amount. Control method. 2. A blower for a combustion device, comprising: a blower for introducing combustion air to a burner; and a blower control means for applying a voltage to the blower to control the blower according to a required combustion air amount at that time. A means for producing a pulse signal proportional to the number of revolutions emitted from the blower, and a load amount monitoring means for obtaining the load amount applied to the blower from the pulse signal and the voltage applied to the blower are provided, and the voltage applied to the blower is A blower for a combustion device, comprising a means for correcting the value corresponding to the load amount.