JPH05346228A - Controller for combustion equipment - Google Patents

Abstract

PURPOSE:To provide a controller, by which data are simplified and the simplification is confirmed easily while a combustion test, etc., are facilitated and development of which is hardly borne, for a combustion equipment. CONSTITUTION:An air-blower control formula computing section 42a computing air-blower control operation formula from the minimum quantity of combustion and the maximum quantity of combustion and the minimum number of revolution and maximum number of revolution of an air blower II corresponding to these quantities of combustion respectively and a proportional-valve control formula computing section 43a computing proportional-valve control operation formula from the minimum number of revolution and the maximum number of revolution and the minimum current value and maximum current value of a proportional valve 12 corresponding to these number of revolution respectively are installed to a microcomputer 40. The control value (the number of revolution) of the air blower 11 is computed in response to the target quantity of combustion, the current value of the proportional valve 12 is calculated in response to the number of revolution of the air blower 11 detected, and the air blower 11 and the proportional valve 12 are controlled respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a combustion device, which calculates a control value for controlling the combustion device by a control calculation formula.

[0002]

2. Description of the Related Art In combustion equipment such as water heaters and heaters, a microcomputer is used to control the combustion state of the combustion equipment, and it is set by a predetermined arithmetic expression constructed by a program in the microcomputer. The burner combustion amount is determined based on the temperature, etc., and the control values of the blower and proportional valve are calculated corresponding to the determined combustion amount, and the blower and proportional valve are controlled based on each control value. ..
Conventionally, an arithmetic expression for calculating each control value is set for each model of the water heater and the heater based on the capacity of the burner and the like, and therefore, in order to specify each arithmetic expression, the memory is A plurality of data for designating an arithmetic expression and its arithmetic range are stored, and these data are stored as unique data corresponding to each model even if the models are similar.

[0003]

DISCLOSURE OF THE INVENTION As described above,
The arithmetic expression used to control the combustion equipment is set so that a control value that is appropriately determined based on a combustion test performed after the burner unit, the fuel supply system, the blast system, etc. are combined as the combustion equipment can be obtained. It is something. Therefore, at the development stage where a combustion test is required, the memory of the microcomputer contains, for example, a program only for determining the combustion sequence and the combustion amount, but the control value of the blower and the proportional valve that affect the combustion state are included. The arithmetic expression for determining the control value is not included in the program because it is preferable to include it as the data of the arithmetic expression only after determining the appropriate combustion characteristics. Therefore, in the combustion test, for example, when an arithmetic expression represented by a linear expression is given, the minimum control value and the maximum control value assumed corresponding to the minimum combustion amount and the maximum combustion amount set in the combustion equipment are set. It was necessary to calculate the coefficient and constant of the linear equation from the value and test. Further, when the determined arithmetic expression is stored in the memory as program data after determining these coefficients and constants, the data for specifying the arithmetic expression includes the combustion amount and the control value corresponding thereto. It becomes the maximum value, each minimum value, and the coefficient and constant in the linear expression, and the number of data is 6 for each linear expression. Even when confirming after storing these data in the memory, the linear expression is used. Calculation is required.

An object of the present invention is to provide a control device for a combustion device, which simplifies data and facilitates its confirmation, and facilitates a combustion test or the like and reduces the burden of development.

[0005]

SUMMARY OF THE INVENTION The present invention provides a control value having a control arithmetic expression for calculating a control value of a combustion device corresponding to a target combustion amount determined based on a set temperature, a detected temperature of a thermistor and the like. In a control device comprising a calculation means and controlling a combustion device based on a control value calculated by the control calculation formula, in a plurality of combustion amount information and a plurality of control value information respectively corresponding to the plurality of combustion amount information, The technical means includes an arithmetic expression calculating means for calculating the control arithmetic expression in the control value calculating means.

[0006]

In the control apparatus for the combustion equipment of the present invention, the control calculation formula is calculated by giving a plurality of combustion amount information and control value information corresponding to each combustion amount information to the calculation formula calculation means. When the target combustion amount is determined, the control value is calculated by the calculated control calculation formula. The combustion device is controlled by the calculation result of the control calculation formula. Therefore, at the stage of developing the control device, the most appropriate control value can be found by giving an arbitrary control value corresponding to a plurality of pieces of combustion amount information to the arithmetic expression calculation means to conduct a combustion test of the combustion equipment. It's easy. At that time, for example, if the control arithmetic expression is given by a linear expression, the linear expression can be specified by giving a maximum combustion amount, a minimum combustion amount, and two control values corresponding to them, The information such as the coefficient and the constant of the equation becomes unnecessary, and the number of information necessary for specifying the combustion characteristics can be reduced. When the combustion characteristics are determined after performing a combustion test or the like, it is possible to store a plurality of combustion amount information for specifying the control calculation expression and the corresponding control value information in the storage means. The control device can have combustion characteristics.

[0007]

According to the present invention, the control arithmetic expression for determining the combustion characteristic is calculated by giving a plurality of pieces of combustion amount information and a plurality of pieces of control value information corresponding thereto.
It is possible to reduce the number of information (data) required to specify the control arithmetic expression. Therefore, a combustion test or the like in development is facilitated, and information (data) after the control characteristics are determined can be easily confirmed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described based on the embodiments shown in the drawings. In the gas water heater 1 schematically shown in FIG. 1, 10 is a burner, 11 is a blower for supplying combustion air to the burner 10, and the combustion amount of the burner 10 is controlled by a proportional valve 12 provided in a gas supply pipe 11. Adjusted. In addition, in the gas supply pipe 11, 13 and 14 are gas solenoid valves, which are provided with an ignition electrode 15, a frame rod 16, and a thermocouple 17 in proximity to the burner 10, respectively.

On the other hand, 20 is a heat exchanger heated by the combustion heat of the burner 10, 21 is a water supply pipe for supplying water to the heat exchanger 20, and 22 is a hot water outlet pipe through which hot water heated by the heat exchanger 20 flows out. , 23 are tap water pipes 2 for water that is not heated by the heat exchanger 20.
A bypass pipe 24 directly leading to 2 is a bypass mixing valve for adjusting the amount of water passing through the bypass pipe 23 by changing the opening degree as necessary. In the water supply pipe 21, 25 is a water amount control valve, 26 is a water amount sensor for detecting the flow rate, 27 is a water supply temperature thermistor for detecting the water supply temperature, 28 is a hot water outlet pipe thermistor 28, and 29 on the downstream side of the heat exchanger 20 is It is a heating temperature thermistor. Gas water heater 1 having the above configuration
In the above, the control device 30 performs the combustion control of the burner 10, the flow rate control for adjusting the flow rate of the water supply pipe 21, and the bypass water amount control for adjusting the passing water amount of the bypass pipe 23.

The control device 30 is mainly composed of a microcomputer (hereinafter referred to as a microcomputer) 40, an input circuit 31, and a drive circuit 32, and is provided with a main remote controller 33 and a bath remote controller 34 for setting the operating state of the gas water heater 1. There is. The microcomputer 40 is an integrated circuit element in which a memory 50 as an input / output interface circuit and a storage device is housed in the same chip.
Programs for each control and various data set according to the model are stored. In the control by the control device 30, water flow starts according to the opening operation of a water tap (not shown) provided at the downstream end of the hot water outlet pipe 22, and the water amount sensor 26
When water flow is detected based on the flow rate signal of the burner 10, combustion of the burner 10 is started in a predetermined sequence, the combustion amount of the burner 10 is controlled based on signals of each remote controller, each thermistor, etc. When the water flow stop is detected, the combustion of the burner 10 is stopped by controlling the amount of water passing through the bypass pipe 21 and the amount of water passing through the bypass pipe 23, respectively.

The combustion control of the burner 10 in the microcomputer 40 will be described below. In order to perform combustion control, the microcomputer 40, as shown in FIG.
1, functional units of a blower control unit 42 and a proportional valve control unit 43 are provided. The combustion amount determination unit 41 first determines the combustion amount Q of the burner 10 based on the detection signals of the feed water temperature thermistor 27 and the water amount sensor 26 and the temperature set by one of the remote controls by feedforward control, and then the hot water discharge. When the detection signal of the temperature thermistor 28 satisfies a predetermined condition, the combustion amount Q is determined by feedback control based on each signal including the detection signals of the heating temperature thermistor 29 and the hot water temperature thermistor 28, and the combustion temperature Q is determined according to the set temperature. Correction is performed so that the tap water temperature can be obtained.

The range of the determined combustion amount Q corresponds to the capacity range of the burner 10 and the like for each model, and the minimum combustion amount Qmin and the maximum combustion amount Qmax are stored in the memory 50 as combustion amount range data. Has been given. In the combustion control, the blower 11 and the proportional valve 12 are controlled according to the combustion amount Q determined as described above, but the ratio between the combustion air amount and the fuel gas amount supplied to the burner 10 becomes appropriate. In order to achieve this, in the present embodiment, the blower controller 42 drives and controls the blower 11 in accordance with the determined combustion amount Q, the rotational speed of the blower 11 is detected, and the proportional valve controller 43 supplies the energizing current of the proportional valve 12. It controls the value.

In the blower control unit 42, the combustion amount determining unit 41
The blower control arithmetic expression for determining the rotation speed N of the blower 11 corresponding to each combustion amount Q from the minimum combustion amount Qmin to the maximum combustion amount Qmax determined in And the corresponding rotation speed N
Is calculated and the current value of the blower 11 is controlled so that the rotation speed N is obtained. Here, the blower control arithmetic expression is not directly given in advance by the program according to the model, but is given to the memory 50 as the maximum rotation speed Nmax and the minimum rotation speed Nmin of the blower 11 set for each model. Rotating speed range data,
Based on the above combustion amount range data, the microcomputer 4 depending on the model
It is calculated and functions within 0, and the blower control unit 42 is provided with a blower control formula calculation unit 42a for calculating a blower control calculation formula by a program.

Similarly, in the proportional valve control unit 43, the proportional valve controller 43 is proportional to each rotation speed N from the minimum rotation speed Nmin to the maximum rotation speed Nmax detected according to the operation of the blower 11 controlled as described above. A proportional valve control arithmetic expression for determining the current value I of the valve 12 is provided, and when the rotation speed N of the blower 11 is detected by the rotation speed detection circuit, the current value I corresponding thereto is calculated, The current value of the proportional valve 12 is controlled so that the current value I is obtained. Here, the proportional valve control arithmetic expression is not directly given by the program in the memory 50 like the above blower control arithmetic expression, but is proportional to the rotational speed range data set for each model. It is calculated in the microcomputer 40 according to the model from the current value range data given to the memory 50 as the maximum current value Imax and the minimum current value Imin of the valve 12 and functions. Proportional valve control formula calculation unit 4 for calculating a proportional valve control calculation formula
3a is provided.

Summarizing the above, in the present embodiment,
The combustion amount Q and the rotation speed N of the blower 11 have a linear relationship between the maximum value and the minimum value, as shown by a straight line A in FIG. The number N and the current value I of the proportional valve 12 have a linear relationship between the maximum value and the minimum value, for example, as shown by a straight line B in FIG. Therefore, each of the above control arithmetic expressions can be expressed as a part of a linear function, and the blower control expression calculating unit 42a uses the straight line A
The blower control arithmetic expression showing the above is expressed by the coordinates a (Qmax,
Nmax), b (Qmin, Nmin), and in the proportional valve control equation calculation unit 43a, a proportional valve control equation showing a straight line B is determined by two points determined by the rotation speed N and the maximum and minimum values of the current value I. Coordinates c (Nmax, Imax), d
It is calculated from (Nmin, Imin).

As is clear here, as the information for specifying each control arithmetic expression, there are only six data indicating the maximum value and the minimum value for the combustion amount Q, the rotation speed N, and the current value I, respectively. In the past, the coefficients and constants required to show a straight line are not included. Therefore, in the control device 30 provided in a plurality of types of water heaters having the same basic design, among the data provided to the memory 50 provided in the microcomputer 40, the data different for each model is the above combustion amount. Since there are only six pieces of data indicating the maximum and minimum values of Q, rotation speed N, and current value I, the number of data that needs to be confirmed when checking the data for each model It will be less than before.

In a combustion test before each data is determined, an arbitrary rotation speed N corresponding to two combustion amounts Q and an arbitrary current value I corresponding to these two rotation speeds N are respectively set. Since it is possible to easily carry out a test relating to an arbitrary control characteristic only by giving it as control value information, it is possible to reduce the load when giving data for the test. As a result, a combustion test or the like is facilitated at the development stage of the device, and also when confirming the data in the memory 50 after determining the combustion characteristics, the burden of confirmation is small and the data can be confirmed easily.

In the gas water heater 1 of the present embodiment having the above-described structure, the memory 50 does not store six data indicating the maximum value and the minimum value of the combustion amount Q, the rotation speed N, and the current value I. Thus, a combustion test or the like can be easily performed, and appropriate data can be easily determined. Further, even when the data is confirmed after being stored in the memory 50, since the number of data to be confirmed is small, it can be easily confirmed. In the above embodiment, the blower 11 was controlled according to the determined combustion amount Q, and the proportional valve 12 was controlled according to the rotational speed N of the blower 11, but both the blower 11 and the proportional valve 12 burned. The quantity Q may be directly controlled. Although the gas water heater 1 is shown in the above embodiment, a hot air heater, a floor heater or the like may be used.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a gas water heater showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a control device of a gas water heater showing an embodiment of the present invention.

FIG. 3 is a functional block diagram showing a functional configuration of a microcomputer in the control device according to the embodiment of the present invention.

FIG. 4 is a control characteristic diagram showing the rotation speed of the blower with respect to the combustion amount by the microcomputer in the embodiment of the present invention.

FIG. 5 is a control characteristic diagram showing the current value of the proportional valve with respect to the rotation speed of the blower by the microcomputer in the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 gas water heater (combustion equipment) 30 control device (combustion equipment control device) 42 blower control unit (control value calculation means) 42a blower control formula calculation portion (calculation formula calculation means) 43 proportional valve control portion (control value calculation means) ) 43a Proportional valve control formula calculation unit (calculation formula calculation means)

Claims (1)

[Claims] 1. A control value calculating means having a control calculation formula for calculating a control value of a combustion device corresponding to a target combustion amount determined based on a set temperature, a detection temperature of a thermistor, etc. In a control device for controlling a combustion device based on a control value calculated by a formula, the control in the control value calculation means from a plurality of combustion amount information and a plurality of control value information respectively corresponding to the plurality of combustion amount information. A control device for a combustion device, comprising an arithmetic expression calculating means for calculating an arithmetic expression.