JPS6066015A - Combustion control system - Google Patents

Abstract

PURPOSE:To control the temperature of hot water at optimum gains without varying control gains by detecting the frequency of a power supply for a combustion control system and arithmetically determining the optimum number of revolution to the frequency when the power supply is turned ON. CONSTITUTION:When a power supply for a combustion control system is turned ON, a power supply frequency detecting section 311 detects the frequency of the power supply, and outputs a frequency information (k) to a phase arithmetic section 312. The phase arithmetic section 312 memorizes and holds the frequency information (k) while arithmetically determining a phase control angle, where a fan motor 4 is brought to the optimum number of revolution, on the basis of the frequency information (k) and the aimed number of revolution (e), and outputs the phase control angle to a fan motor driving section 125 as a tripper signal (j). Accordingly, the fan motor 4 is turned and driven by the optimum number of revolution required for controlling the temperature of hot water regardless of applied power supply frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention controls the amount of combustion in a burner in a combustion device such as a water heater according to the amount of output, thereby controlling the temperature of hot water discharged from a heat exchanger. Regarding the combustion control device that maintains a controlled temperature,
In particular, combustion control controls the rotation speed of the fan motor that supplies combustion air to the burner based on the deviation between the outlet temperature of the heat exchanger and the target temperature, thereby adjusting the valve opening of the pressure equalizing valve as appropriate. Concerning improvements to equipment.

(Prior art and its problems) Figure ffi1 is a diagram showing the basic configuration of a lake boiler equipped with a combustion control device, which is the subject of the present invention. In the same figure: 1.
A temperature detector 2 for detecting the hot water temperature is provided on the outlet side of the boiler exchanger 1, and a water flow detector 3 for detecting water flow is provided on the water inlet side.

The fan motor 4 supplies combustion air to the burner 5, and the gas supply path of the burner 5 includes a source valve 6 that turns on and off the gas supply, a gas governor 7, and a gas governor 7 that controls the blowing air pressure of the fan motor 4. A pressure equalizing valve 8 is provided which changes the valve opening accordingly and adjusts the amount of gas supplied to the burner 6 in proportion to the air pressure.

Further, in relation to the burner 5, an igniter 9 that generates an ignition spark and a flame detector 10 that detects whether or not the ignition is normally ignited by the ignition operation are provided. J3.11 is a wind pressure switch for checking the operation of the fan motor 4.

Each of the above-mentioned human humidity meters is connected to a control circuit 12, and this control circuit 12 is provided with a humidity setting device 13 for setting a target temperature.

FIG. 2 is a block diagram showing the configuration of the portion of the control circuit 12 to which the present invention is applied as an operational system diagram for hot water temperature control. As shown in the figure, this control system is composed of a feedback loop. The basic combination of this control circuit 12 will be explained below along with the basic operation of the hot water temperature control 311.

First, when a water flow to the heat exchanger 1 is detected by the water flow detector 3, the main valve 6 is opened and the igniter 9 is activated. At the same time, the motor 4 is driven. Then, the amount of air blown by the fan motor 4 increases toward a predetermined value, and the valve 1tt of the pressure equalizing valve 8 increases in proportion to the air pressure.
1 degree increases, and the combustion in bar 5 grows toward a predetermined state.

When the temperature detector 2 detects that the hot water temperature of the heat exchanger 1 has risen, the control circuit 12 performs the following control operation. First, the deviation detection section 121 calculates the deviation C between the hot water detection signal a from the temperature detector 2 and the target temperature signal S from the target temperature setting device 13. Next PID calculation unit 1
At step 22, a PID calculation is performed on the deviation C to create a predetermined control amount d. Next, the target rotation speed calculating section 123 calculates the target rotation speed e of the fan motor 4 based on this control II ffi d. And phase calculation section 1
24, the fan motor 4 is controlled based on the target rotation speed e.
The phase angle of the rotating magnetic field that drives the rotor is calculated and determined, and the signal j is output to the fan motor drive section 125 as a trigger signal. In the fan motor drive unit 125, a switching element is provided to turn on and off the drive current of the fan motor 4.
), and this switching element controls the entire phase of the drive current of the fan motor 4 at the conduction angle determined by the trigger signal j.

As a result, the rotation speed of the fan motor 4 becomes a predetermined value, and a predetermined air pressure f corresponding to this rotation speed is transmitted to the pressure equalizing valve 8. As a result, the opening degree of the pressure equalizing valve 8 becomes a predetermined value, and the amount of gas supplied to the burner 5 becomes appropriate.

In this way, the hot water temperature is controlled to be the set temperature. The above operations are repeated to control and maintain the outlet humidity at the set humidity, and combustion in the burner 5 continues at a predetermined amount of gas. Note that if there is a change in the set humidity or the amount of hot water dispensed, this is fed back as a change in the hot water temperature, and the hot water output m += i is corrected by the hot water temperature control operation.

In other words, the combustion control system to which the present invention is directed makes the combustion air-fuel ratio in the burner 5 appropriate by controlling the rotation speed of the fan motor 4.

By the way, since there are two types of power supply frequencies in Japan, this type of combustion control device is likely to be of a shared type.

Therefore, in the conventional shared type combustion control device, the rotation speed of the fan motor is controlled using a phase angle calculation formula that makes the rotation speed of the fan motor intermediate between 50H2 and 601-IZ.
ll'! I had decided to do it.

However, in this case, the control gain is 50 Hz and 6O
Since this is different from that of f-1z, there are drawbacks such as over/under temperature measurement control and the risk of hunting.

(Object of the Invention) An object of the present invention is to provide a common type combustion control device that can control hot water temperature with an optimum gain regardless of the power frequency.

(Configuration and Effects of the Invention) In order to achieve the above object, the present invention provides a temperature detector for detecting the outlet temperature of a heat exchanger, a target temperature setting device, a fan motor for supplying combustion air to a burner, a pressure equalizing valve whose valve opening changes according to the air pressure of the fan motor to adjust the amount of fuel supplied to the burner; a humidity detection signal of the temperature sensor; and an eye aJi temperature signal of the target temperature setter. a rotation speed determining means that calculates and determines a target rotation speed of the fan motor based on a change in the fan motor; a power frequency detector that detects a power frequency; The fan motor is characterized by comprising a phase angle determining means for calculating and determining the phase of the drive current of the fan motor.

According to this configuration, when the combustion control device is powered on, the power frequency is detected and the frequency information is stored and held. Then, since the optimum rotational speed corresponding to this frequency is determined by calculation, the hot water temperature can be controlled with the optimum gain without causing any fluctuation in the control gain.

(Description of Embodiments) FIG. 3 is a block diagram showing the control circuit of the combustion control device according to the present invention as an operation system diagram for temperature and humidity control. In addition,
Parts with the same names as in FIG. 2 are given the same reference numerals and their explanations are omitted, but the above-mentioned hot water temperature control operation of the control circuit 12 of the conventional device was performed by a combination of discrete parts. The hot water temperature control operation of the control circuit 31 of the apparatus of this embodiment is performed by a microcomputer.

The control circuit 31 according to the present invention includes a power frequency detection section 311 including a power frequency detector;
The frequency information k from the target rotation speed calculation section 123 is inputted to the target rotation speed e from the target rotation speed calculation section 123.

The power supply frequency detection section 311 detects the power frequency when the combustion control device is powered on, and outputs frequency information k to the phase calculation section 312. The phase calculation section 312t' stores and holds the frequency information k, and calculates and determines the control angle at which the fan motor 4 has the optimum rotation speed based on this frequency information and the target rotation speed e, and uses the control angle as described above. 1 to the fan motor drive unit 12 as the trigger signal j
Tsunozuru appears on 5th.

As a result, the fan motor is driven to rotate at the optimal rotational speed necessary for i-cooling control, regardless of the frequency of the applied power supply.

[Brief explanation of the drawing]

Fig. 1 is a basic configuration diagram of a boiler equipped with a combustion control device according to the present invention, which is attached to a ship; Fig. 2 is a block diagram showing the control circuit of the conventional device described above as an operation system diagram for hot water temperature control; Fig. 3; 1 is a block diagram showing an embodiment of the combustion control device according to the present invention as an operational system diagram for hot water control; FIG. 1... Heat exchanger 2... Temperature detector 4... Fan motor 5... Burner 8 ...... Pressure equalization valve 13 ... Target temperature regulator 31 ... Control circuit 311 ... Power supply frequency detection section 312 ... Phase calculation section special VF Applicant Tateishi Electric Co., Ltd. 1000 layers? Jigosha

Claims (1)

[Claims] (1) A temperature detector that detects the hot water temperature of the heat exchanger, a target g1 setting device, a fan motor that supplies combustion air to the burner, and a valve opening that changes depending on the air pressure of the fan motor. , a pressure equalization valve that adjusts the amount of fuel supplied to the burner, and a target rotation speed of the fan motor based on changes in the mixture detection signal of the temperature sensor and the target temperature signal of the target temperature setting device. a power supply frequency detector that detects a power supply frequency; and a phase angle that calculates and determines the phase of the drive current of the fan motor based on the target rotation number and the detection frequency of the power supply frequency detector. A combustion control device characterized by comprising: determining means.