JP2529503B2 - Combustion control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for heating water, heating means for heating the heat exchanger, target temperature setting means for setting a target hot water temperature, and the target hot water temperature. There is provided computing means for computing the heating amount of the heating means by substituting the deviation of the tapping temperature from the above into a predetermined computing expression, and control means for controlling the heating amount of the heating means based on the information of the computing means. Combustion control device.

[0002]

2. Description of the Related Art The above combustion control device is used for a water heater and the like. Conventionally, the coefficient in the above-mentioned arithmetic expression was generally a fixed value. That is, the heating amount of the heating means is uniquely determined based on only the deviation.

[0003]

When the amount of water supplied to the heat exchanger is large, it is necessary to control the heating amount of the heating means to be large even when the deviation is the same as when the amount is small. However, in the above-mentioned conventional technique, even if the amount of water supplied to the heat exchanger is different, if the deviation is the same, the heating amount of the heating means is basically the same. So, for example,
If a suitable coefficient is set when the water supply amount is large, the operating amount of the heating amount becomes excessive and hunting occurs when the water supply amount is small. On the other hand, conversely, if a coefficient suitable for a small amount of water supply is set, the operation amount becomes insufficient and the rise time becomes long when the amount of water supply becomes large. An object of the present invention is to eliminate the above-mentioned conventional drawbacks and to make the coefficient in the above-mentioned arithmetic expression appropriate according to the water supply amount etc. to improve the control characteristics of the combustion control device.

[0004]

In order to achieve this object, the characteristic structure according to the present invention is provided with a water amount detecting means for detecting the amount of water supplied to the heat exchanger, and the computing means is provided with a large amount of water supplied. It is configured such that the coefficient in the arithmetic expression is set to a larger value and the coefficient is set to a larger value when the deviation is negative than when the deviation is positive.

[0005]

The operation of the above characteristic structure is as follows. Since the coefficient is set to a larger value as the water supply amount increases, the manipulated variable of the heating amount increases as the water supply amount increases, even if the deviation is the same. Therefore, the operation amount of the heating amount can be set to an appropriate value according to the water supply amount at that time. Moreover, the magnitude of the coefficient is not simply set by the magnitude of the amount of supplied water, but the deviation of the actual hot water discharge temperature from the target hot water discharge temperature is also taken into consideration. The deviation is originally taken into consideration as a variable of an arithmetic expression for calculating the heating amount of the heating means, but it should be more positively influenced to set the coefficient of the arithmetic expression. And specifically,
The magnitude of the coefficient is set depending on whether the deviation is positive or negative. It is considered that the deviation becomes negative when overshoot occurs. Therefore, by setting the coefficient to a large value and increasing the operation amount of the heating amount, the overshoot can be eliminated relatively quickly. That is, in consideration of the fact that the discomfort given to the user of the hot water becomes stronger in the state of overshooting, the overall tendency is to more strongly suppress the hot water temperature from becoming higher than the target hot water temperature. .

[0006]

According to the above-mentioned characteristic structure, the operation amount of the heating amount can be set to an appropriate value according to the water supply amount at that time, and the overshoot can be eliminated relatively quickly. Therefore, the combustion control device having excellent control characteristics can be obtained. Can be obtained. Therefore, for example, even if the amount of hot water supply increases or decreases during hot water supply, the combustion control is accurately executed to suppress the temperature change, and even if an overshoot of the hot water temperature occurs, the overshoot is resolved relatively quickly, so the overall It is possible to provide the user with a comfortable hot water use environment. Further, regarding the two factors of the feed water amount and the deviation that affect the result of the combustion control, by uniformly treating them as the setting of the coefficient of a predetermined calculation formula for calculating the heating amount, the control configuration becomes This is to avoid complication as much as possible.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment in which the present invention is applied to a water heater will be described below with reference to the drawings. As shown in FIG. 1, a water heater having a heat exchanger 1 for heating water and a burner 2 as a heating means for heating the heat exchanger 1 has a hot water supply passage W2 at a hot water tap 4. Connected through. W1 in the figure
Is a water supply channel for the heat exchanger 1. The fuel gas supply path G1 for the burner 2 is provided with two on-off valves 9 and 10 for intermittently supplying the fuel gas and an electromagnetic gas amount adjusting valve 11 for adjusting the fuel gas supply. The water supply passage W1 is provided with a water amount sensor S1 as a water amount detecting means for detecting the amount Q of water supplied to the heat exchanger 1, and a water temperature sensor S2 for detecting an incoming water temperature Ti to the heat exchanger 1. . Hot water supply path W
A hot water temperature sensor S3 for detecting the hot water outlet temperature Tm of the heat exchanger 1 is provided at 2. In the figure, 14 is an igniter,
Reference numeral 15 is a frame rod that detects whether or not the burner 2 is ignited. These are connected to the control device H, respectively.

Further, a remote controller R for instructing control information to the control device H is provided. The remote controller R includes an operation switch 20 for instructing start / stop of hot water supply operation, an operation lamp 21, and a burner 2. A combustion lamp 22 that is turned on during combustion is provided, and a target temperature setting device 23 as a target temperature setting device that sets a target hot water outlet temperature Ts on the outlet side of the heat exchanger 1.

Control of heating amount Ip of burner 2 (combustion control)
Will be added. The heating amount Ip of the burner 2 is obtained based on the equation 1 so that the hot water discharge temperature Tm becomes the target hot water discharge temperature Ts. That is, equation 1 corresponds to a predetermined arithmetic expression.

[0010]

## EQU1 ## Ip = Ka × (Ts−Ti) × Q + Kp × Δt + Ki × ∫Δtdt

Here, Ka is a constant and Δt is a deviation of the outlet heated water temperature Tm from the target outlet heated water temperature Ts. Also, Kp and Ki
Is a coefficient whose value is changed and set based on the water supply amount Q and the deviation Δt.

The setting of the coefficients Kp and Ki will be further described. As shown in FIG. 3, here, there are six types of coefficients Kp and K.
i is prepared. Then, one of the coefficients Kp, K
i will be selected 3 and set. The numbers in the figure are hexadecimal numbers. First, it is divided into two types depending on whether or not the deviation Δt is positive. When the deviation Δt is positive, the water supply amount Q is 7
It is divided into two types depending on whether it is less than (liter / min). When the water supply amount Q is less than 7 (liter / min), it is further divided into two types depending on whether the deviation Δt is less than 1 (deg). Similarly, when the water supply amount Q is 7 (liter / min) or more, it is further divided into two types depending on whether the deviation Δt is less than 3 (deg). That is, when the deviation Δt is positive, there are four types. When the deviation Δt is negative, it is divided into two types depending on whether or not the water supply amount Q is less than 7 (liter / min). By the way, when the water supply amount Q is the same, the coefficients Kp and Ki set when the deviation Δt is negative are larger than the coefficients Kp and Ki set when the deviation Δt is positive. Further, when the condition of the deviation Δt is the same, the water supply amount Q is 7
Coefficient K set when (liter / min) or more
p and Ki are larger than the coefficients Kp and Ki set when the water supply amount Q is less than 7 (liter / min).

Next, the operation of the controller H will be described with reference to the flow charts shown in FIGS.
First, the necessity of hot water supply is determined based on the information of the operation switch 20, and if hot water supply is not required, it is determined whether or not hot water supply is currently being performed. If the hot water is not being supplied up to now, it returns as it is. If the hot water is being supplied up to the present, the process returns after executing the fire extinguishing process. When it is determined that hot water supply is required, it is determined whether or not the hot water tap 4 is open based on the information from the water amount sensor S1. When the hot water tap 4 is closed, it is determined whether or not hot water is being supplied up to the present time. If the hot water is not being supplied up to the present time, the process returns as it is. To return. When it is determined in the above determination that the hot water tap 4 is open, it is determined whether or not the ignition is being performed, and the ignition process for igniting the burner 2 is executed only when the ignition is not being performed. . Next, the coefficients Kp and Ki are calculated by the above procedure.
After setting, the heating amount Ip of the burner 2 is obtained based on the equation 1. Then, the opening degree of the gas amount adjusting valve 11 is controlled so as to reach the heating amount Ip. The above operation is repeated every elapse of a predetermined time.

That is, using the control device H, the calculation means 100 for calculating the heating amount Ip of the burner 2 and the control means 101 for controlling the heating amount Ip of the burner 2 based on the information of the calculation means 100 are provided. It is configured.

[Other Embodiments] In the above embodiment, the heating amount Ip of the burner 2 is obtained by feedforward + feedback, but it may be obtained only by feedback.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a block diagram of a control configuration.

FIG. 2 is a flowchart of control operation.

FIG. 3 is a flowchart of control operation.

[Explanation of symbols]

 1 Heat Exchanger 2 Heating Means 23 Target Temperature Setting Means 100 Computing Means 101 Control Means Ip Heating Amount Kp, Ki Coefficients Q Water Supply Amount S1 Water Amount Detection Means Ts Target Outlet Temperature Tm Outlet Temperature Δt Deviation

Claims (1)

(57) [Claims] 1. A heat exchanger (1) for heating water, a heating means (2) for heating the heat exchanger (1), and a target temperature setting means for setting a target tap water temperature (Ts). (2
3) and the outlet heated water temperature (T) from the target outlet heated water temperature (Ts).
The calculation means (10) for calculating the heating amount (Ip) of the heating means (2) by substituting the deviation (Δt) of m) into a predetermined calculation expression.
0) and a control means (101) for controlling the heating amount (Ip) of the heating means (2) based on the information of the calculation means (100). A water amount detecting means (S1) for detecting the water supply amount (Q) to the exchanger (1) is provided, and the calculating means (10) is provided.
0) sets the coefficients (Kp) and (Ki) in the arithmetic expression to larger values as the water supply amount (Q) increases , and
On the other hand, when the deviation (Δt) is negative,
A combustion control device configured to set the coefficients (Kp) and (Ki) to large values .