JP3137778B2 - Water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply apparatus having an arithmetic expression setting section and an arithmetic expression correction section, which can control the rotation speed of a combustion fan.

[0002]

2. Description of the Related Art In a conventional hot water supply device, a required heat amount calculating section for calculating a required heat amount based on a set temperature, a feed water temperature and a hot water supply amount, or a required heat amount correction based on the set temperature and an actual hot water supply temperature. A correction calorie calculation unit
2. Description of the Related Art There is known a hot water supply device configured to control the number of revolutions of a combustion fan in accordance with a required heat amount or a corrected heat amount.

[0003]

The conventional hot water supply apparatus is used for a hot water supply apparatus since the number of revolutions of a combustion fan is uniformly controlled in accordance with the amount of heat required for obtaining a set temperature and the correction amount of heat. Insufficient air volume because the actual combustion amount differs from the required combustion amount or the corrected combustion amount depending on the type of gas fuel ( heat amount ) and the strength of gas pressure, and the number of revolutions of the combustion fan is lower than the actual combustion amount. There is a risk that incomplete combustion may occur, or that the gas burner may be extinguished due to an excessive amount of air due to an excessive number of revolutions.

[0004] As an example, FIG. 7 shows the number (burning amount) of a conventional hot water supply apparatus when the amount of heat is small or the gas pressure is weak.
And characteristic diagrams of rotation speed. In FIG. 7, when the correction number 10 is necessary to secure the actual number 8, the rotation speed is corrected to the number 10 even though the actual combustion amount is 8.
Therefore, the difference between the actual rotation speed and the required rotation speed as shown in the figure becomes excessive.

The present invention has been made to solve such a problem, and has as its object the purpose of using a type of fuel (gas heat).
It is an object of the present invention to provide a hot water supply device capable of controlling the number of revolutions of a combustion fan required to secure an air volume necessary for actual combustion even if the amount ( volume ) and the condition (strength of gas pressure) are different.

[0006]

In order to solve the above-mentioned problems, a hot water supply apparatus according to the present invention comprises a set temperature Ts for hot water supply.
The required combustion amount of fuel is determined from the water supply temperature Tc and the hot water supply amount Q, and a signal related to the required combustion amount is calculated based on the hot water supply temperature Th.
Signal related to the corrected combustion amount multiplied by the feedback ratio
Controls the valve opening to regulate the amount of fuel combustion
Calculation of the number of revolutions of the combustion fan
The fuel with the corrected combustion amount is burned by the air volume accompanying the rotation speed.
In hot water supply device for performing hot water supply by the Fidoba
Is determined based on the difference between the set temperature Ts and the hot water supply temperature Th.
It has a feedback ratio calculation unit for PID calculation, this
The feedback obtained by the operation of the feedback ratio operation unit.
After the feedback ratio stabilizes at a constant value,
Multiply the signal related to the back ratio by the signal calculated by the above equation
Then, in place of the above-mentioned arithmetic expression, an arithmetic expression consisting of the multiplied signal is used.
And wherein <br/> obtaining the rotational speed of the combustion fan for the correction combustion amount.

[0007]

In the water heater according to the present invention, a standard fuel is required.
After the combustion control based on the combustion amount is stabilized, the non-standard fuel
The feedback ratio αfb accompanying the combustion of
The arithmetic expression is corrected by the arithmetic expression correction unit. This allows
The rotational speed of the combustion fan can be controlled by a corrected arithmetic expression suitable for non-standard fuel combustion .

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram of a hot water supply apparatus according to the present invention, using a hot water supply temperature Th as a parameter. In FIG. 1, the hot water supply apparatus includes a required number calculation unit 1, a correction number calculation unit 2, a valve opening / burning amount (number) conversion unit 4, a proportional valve control unit 5, and a correction coefficient calculation unit 6. And a timer 7 and a memory 8
, An arithmetic expression correcting unit 9, an arithmetic expression setting unit 10, and a comparing unit 1.
1, a rotation speed calculation unit 12, and a fan rotation speed control unit 13
, A combustion fan 14, a gas proportional valve 15, a heat exchanger 16, a feed water temperature (Tc) sensor 17, a hot water temperature (T
h) Sensor 18 and water supply amount (= water supply amount, Q) sensor 1
9 types of sensors.

The required number calculation unit 1 calculates the required amount of heat (number) required to obtain hot water at the set temperature based on the set temperature Ts, the water supply temperature Tc, and the hot water supply amount Q, and calculates the required heat amount (F).
s) Output information 1a.

The correction number calculator 2 includes a PID calculator 2A,
The PID calculation unit 2A is composed of an adder 2B and a multiplier 2C. The PID calculation unit 2A performs a PID calculation based on a value obtained by dividing the deviation ΔTe between the set temperature Ts and the hot water supply temperature Th by the required heat quantity (Fs) from the required number calculation unit 1. Then, the corrected combustion amount (Fo) is calculated by multiplying the required heat amount (Fs) from the required number calculation unit 1 by a value 2b obtained by adding the constant 1 to the result 2a and calculating the corrected combustion amount (F
o) The information 2c is converted to the valve opening / burning amount converter 4 and the comparator 1
1 to provide.

The valve opening / burning amount conversion section 4 converts the corrected combustion amount (Fo) information 2c from the correction number calculating section 2 into valve opening degree information 4a corresponding to the combustion amount. Outputs a valve control signal 5a corresponding to the valve opening information 4a to control the gas proportional valve 15 to adjust the amount of gas required for combustion.

The correction coefficient calculating section 6 calculates a coefficient based on the input parameter (here, the hot water supply temperature Th), and the calculating equation correcting section 9 calculates, for example, the maximum combustion amount of the standard gas stored in the storage section. Correction coefficient calculator 6 for minimum combustion amount
And a combustion amount maximum value correction unit and a combustion amount minimum value correction unit that correct the combustion amount maximum value and the combustion amount minimum value, respectively, by multiplying by a coefficient from.

When the parameter Th is input, the correction coefficient calculator 6 outputs a corresponding correction coefficient α.

In this case, the initial value of the correction coefficient α is stored in the memory 8 as 1 in advance, and when the water heater is started, α = 1 is provided to the arithmetic expression correcting section 9 as correction coefficient information 8a. When the correction coefficient α obtained based on Th continues for a predetermined value set by the timer 7 for a predetermined time, the value is stored in the memory 8 as a new correction coefficient, and is used as correction coefficient information 8a. 9 to provide.

The arithmetic expression correction unit 9 multiplies the maximum combustion amount Fmax and the minimum combustion amount Fmin of the standard gas stored in the storage unit in advance by a correction coefficient α, and obtains Fmax ′ (= αF
max) and Fmin ′ (= αFmin) to output maximum value correction information 9a and minimum value correction information 9b.

The arithmetic expression setting unit 10 includes a combustion fan 14 corresponding to the maximum value correction information 9a and the minimum value correction information 9b from the arithmetic expression correction unit 9 and the maximum combustion amount Fmax and the minimum combustion amount Fmin of the standard gas. The standard coefficient A and the correction coefficient A ′ are set from the rotation speed maximum value Nmax and the rotation speed minimum value Nmin, and are provided to the rotation speed calculation unit 12 as coefficient information 10a.

[0017]

A = (Nmax−Nmin) / (Fmax−Fmin) A ′ = (Nmax−Nmin) / (Fmax′−Fmin ′)

The comparison unit 11 uses the corrected combustion amount (Fo) information 2c from the correction number calculation unit 2 as the maximum value correction information (Fmax ') 9a and the minimum value correction information (Fmi) from the arithmetic expression correction unit 9.
n ′) 9b, and outputs a corrected output combustion amount (Fout) signal 11a to the rotation speed calculation unit 12.

The corrected output combustion amount (Fout) takes the following value according to the corrected combustion amount (Fo) value.

Fout = Fo (Fmin ′ <Fo <Fmax ′) = Fmin ′ (Fo ≦ Fmin ′) = Fmax ′ (Fo ≧ Fmax ′)

The rotational speed calculating unit 12 calculates the rotational speed N from the following equation based on the coefficient information 10a (A, A ') from the arithmetic expression setting unit 10 and the corrected output combustion amount (Fout) signal 11a from the comparing unit 11. The rotation speed information 12a is calculated and sent to the fan rotation speed control unit 13.

[0021]

## EQU00003 ## N = A.times.Fout + B N = A'.times.Fout + B '

FIG. 6 shows a characteristic diagram of the combustion output (Fout) and the rotational speed (N). N = A × Fout + B represents the number of revolutions with respect to the combustion output when the standard gas is used.
= A '× Fout + B' indicates the relationship between the combustion output and the number of revolutions when a gas having a small heat value or a low gas pressure is used.

According to FIG. 6, when a gas having a small heat value or a low gas pressure is used, the maximum value Fmax of the combustion amount and the minimum value Fm of the combustion amount are smaller than when the standard gas is used.
in is calculated using the correction coefficient α as Fmax ′ (= αFma
x) and Fmin '(= αFmin), the rotation speed (N) for the same combustion output (Fout) as the standard gas is reduced.

On the other hand, when a gas having a larger calorific value than the standard gas is used, the same combustion output (Fou) as the standard gas is used.
The rotation speed (N) with respect to t) will be increased.

FIG. 2 is a block diagram of the hot water supply apparatus according to the present invention using the actual number (actual combustion amount) Fr as a parameter. The difference from FIG. 1 is that the actual number calculation unit 3 is added, and the parameter input to the correction coefficient operation unit 6 is the actual combustion amount (real number) Fr.

The actual number calculation unit 3 calculates the actual combustion amount (actual number) of the water heater based on the hot water temperature Th, the water temperature Tc and the hot water amount Q, and obtains the actual combustion amount (Fr) information. 3
a is provided to the correction coefficient calculator 6. It is the same as FIG. 1 except that the input parameter of the correction coefficient α is different.

FIG. 3 is a block diagram of the hot water supply apparatus according to the present invention using the actual number (actual combustion amount) Fr and the correction number Fo as parameters.

The correction coefficient α (= Fo /
It is the same as FIG. 1 except that it becomes Fr).

FIG. 4 is a block diagram of the hot water supply apparatus according to the present invention using the correction number Fo and the required number Fs as parameters.

The correction coefficient α (= Fo /
Fs), except that Fs).

FIG. 5 is a block diagram of the hot water supply apparatus according to the present invention using the feedback ratio αfb as a parameter. In FIG. 5, the correction number calculation unit 2 is composed of a feedback calculation unit 2B and a multiplier, and based on the deviation ΔTe between the set temperature Ts and the hot water supply temperature Th, the required number calculation unit 1
Is calculated by multiplying the information 2d relating to the feedback ratio αfb by the required combustion amount Fs to output a corrected combustion amount Fo, and using the feedback ratio αfb as a correction coefficient as an arithmetic expression correcting unit. 9 to provide.

As shown in FIG. 1, the initial value of the correction coefficient α is constant 1, and when the same value continues for a predetermined time, it is αfb. That is, assuming that the initial value of the correction coefficient α is 1,
When the water heater is started beforehand stored in the memory 8
Provides α = 1 to the arithmetic expression correcting unit 9 as the correction coefficient information 8a.
Offer . In addition, deviation ΔT between set temperature Ts and hot water supply temperature Th
The feedback ratio αfb obtained based on e is a constant value
If the timer continues for a predetermined time set by the timer 7,
The value of the feedback ratio αfb as a new correction coefficient.
The data is stored in the memory 8 and is performed as the correction coefficient information 8a.
This is provided to the equation correction unit 9 .

[0033]

As described above, the water heater according to the present invention is provided with an arithmetic expression for calculating the number of revolutions of the combustion fan.
Feedback based on deviation between constant temperature Ts and hot water supply temperature Th
The rotation ratio of the combustion fan can be controlled by correcting the combustion ratio αfb as a parameter by the arithmetic expression correction unit. Therefore, even when the type ( heat amount ) and condition (gas pressure) of the gas fuel actually used are different from the assumed standard gas, it is possible to secure a fan rotation speed suitable for combustion. Therefore, it is possible to provide a safe hot water supply apparatus in which there is no fear of incomplete combustion due to insufficient rotation speed or flame extinguishing of the gas burner due to excessive rotation speed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a hot water supply apparatus according to the present invention, using a hot water supply temperature Th as a parameter.

FIG. 2 is a block diagram showing the actual number (actual combustion amount) Fr of the hot water supply apparatus according to the present invention as a parameter;

FIG. 3 is a block diagram of the hot water supply apparatus according to the present invention in which the actual number (actual combustion amount) Fr and the correction number Fo are parameters.

FIG. 4 is a block diagram of the hot water supply apparatus according to the present invention, in which a correction number Fo and a required number Fs are used as parameters.

FIG. 5 is a block diagram of the hot water supply apparatus according to the present invention, using a feedback ratio αfb as a parameter.

FIG. 6 is a characteristic diagram of combustion output (Fout) and rotation speed (N).

FIG. 7 is a characteristic diagram of the number (combustion amount) and the rotation speed of a conventional hot water supply device when the amount of heat is small or the gas pressure is weak.

[Explanation of symbols]

 1 Required Number Operation Unit 2 Correction Number Operation Unit 3 Actual Number Operation Unit 4 Valve Opening / Combustion Quantity Conversion Unit 5 Proportional Valve Control Unit 6 Correction Coefficient Operation Unit 7 Memory 8 Timer 9 Operation Expression Correction Unit 10 Operation Expression Setting Unit 11 comparison unit 12 rotation speed calculation unit 13 fan rotation speed control unit 14 combustion fan 15 gas proportional valve 16 heat exchanger 17 water supply temperature (Tc) sensor 18 hot water temperature (Th) sensor 19 water supply amount (= water supply amount Q) Sensor

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toru Tsuruta 43-1, Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Prefecture Inside Nippon Yupro Corporation (72) Inventor Hiroshi Munemura 43-1, Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo (72) Inventor Hiroki Maruyama 43-1, Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Prefecture Inside Japan-Yupro Corporation (56) References JP-A-1-219413 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) F23N 3/08 F23N 5/14 370

Claims (1)

(57) [Claims] 1. A set temperature Ts and a feed water temperature T for hot water supply.
determine the necessary amount of combustion fuel from c and hot water supply amount Q, this必
Feedback based on hot water supply temperature Th based on signal related to required combustion amount
The fuel-related signal multiplied by the fuel ratio
Control the valve opening to control the amount of fuel burned
The rotational speed of the combustion fan is obtained by an arithmetic expression, and the corrected combustion amount is calculated.
Hot water by burning the fuel of
In the hot water supply apparatus, the feedback ratio is set to a set temperature Ts and a hot water supply temperature Th.
Feedback ratio calculation that calculates PID based on the deviation of
And a feedback section which is obtained by the operation of the feedback ratio operation section.
After the feedback ratio stabilizes at a constant value, the feedback
The signal related to the feedback ratio
Multiplication, and an operation consisting of the signal after multiplication instead of the operation expression
The rotation speed of the combustion fan with respect to the corrected combustion amount is calculated by the following equation.
Hot water supply apparatus, wherein the mel.