JPH07198130A - Function switching type combustion device - Google Patents

Abstract

PURPOSE:To smoothen a jump switching between function lines by a method wherein when a void part without an overlapping part is generated between a combustion characteristic line being used, and a combustion characteristic line to be switched to, the combustion characteristic line is switched by a function line switching cushioning operation part. CONSTITUTION:When receiving a jump command from a function line L1 to function line L2, a function line switching cushioning operation part temporarily stops a jump from the function line L1 to L2 by slightly decreasing the combustion function by throttling a water quantity control valve for a time by a specified quantity, when the generation of a void part without an overlapping part between the function line L1 and L2 is found by the judgement by a function line lapping judging part. Then, when the requirement for the increase of the water quantity is recognized, it is judged that the increase of the combustion function is assuredly required, the combustion function jumps from a point Q on the function line L1 to a point C on the function line L2, and the function line L1 is switched to L2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacity-switching type combustion device such as a water heater.

[0002]

2. Description of the Related Art FIG. 6 shows a system configuration of a water heater which is generally used as a combustion apparatus of a capacity switching type. In the figure, a water supply pipe 3 of water as a fluid to be heated is connected to the inlet side of the heat exchanger 2, and the water supply thermistor 10 serving as an input temperature detecting means for detecting the input water temperature is connected to the water supply pipe 3.
And a flow rate sensor 9 as a flow rate detecting means for detecting the amount of water entering. The hot water supply pipe 4 is connected to the outlet side of the heat exchanger 2, and the hot water supply tap 1 is provided on the outlet side of the hot water supply pipe 4. Further, in the hot water supply pipe 4, a water amount control valve 16 as a flow rate control unit whose valve opening amount is controlled by a gear motor,
A hot water outlet thermistor 11 is provided as a hot water outlet temperature detecting means for detecting the hot water outlet temperature.

Below the heat exchanger 2, a burner 7 of a capacity switching type as a combustion heating means, an igniter electrode 18 for igniting the burner 7, and a frame rod electrode 1 for detecting ignition.
9, and a combustion fan 5 as an air supply means for supplying and exhausting gas, a gas nozzle 6 is arranged opposite to the gas inlet of the burner 7, and a gas supply amount is supplied to a gas pipe 8 leading to the gas nozzle 6. A gas proportional valve 13 as fuel supply control means for controlling the valve opening amount by a valve opening amount, and a gas solenoid valve 12 for opening and closing the pipeline are provided. The gas chamber of the gas nozzle 6 is divided into two by a partition wall 46. By closing the capacity switching electromagnetic valve 45, the burner 7 is brought into a one-side combustion state of small capacity, and by opening the capacity switching electromagnetic valve 45, large capacity is achieved. In the two-sided combustion state, the combustion capacity can be switched by opening and closing the solenoid valve 45.

This type of water heater is provided with a control device 14, and a remote controller 15 is connected to the control device 14. The remote controller 15 has a temperature setting unit such as a button for setting the hot water temperature and hot water setting. A temperature display is provided. The controller 14 controls the hot water supply operation of the water heater, and when the hot water tap 1 is opened, the flow rate sensor 9 detects the amount of water input, and when the amount of water input exceeds a certain level (minimum operating flow rate). In response to the signal from the flow sensor 9, the controller 14 rotates the combustion fan 5. Then, when the rotation of the combustion fan 5 enters a predetermined rotation region, the gas solenoid valve 12 and the gas proportional valve 13 are opened to supply the gas to the burner 7, and the ignition operation by the igniter electrode 18 is performed. Frame rod electrode 19
When the gas ignition is detected, the control device 14 performs feedforward control so that the hot water temperature is set to the set temperature, the opening amount of the gas proportional valve 13 is varied, and the hot water temperature output from the heat exchanger 2 is set to the set temperature. After the hot water temperature is stabilized, the combustion control is performed by the combined control of the feedforward control and the feedback control.

As is well known, the hot water supply device is provided with hot water supply combustion capability, and the hot water supply device performs combustion control within the range of this combustion performance to bring the hot water discharge temperature to a set temperature. The combustion capacity given to a water heater is given by the number, which is 1
No. means the burning capacity required to raise 1 liter of water by 25 ° C. per minute.

In other words, the number of products = water input (liter / min) x
It is expressed by the formula of {outflow temperature (° C) -inlet temperature (° C)} ÷ 25. Since the hot water outlet temperature is equal to the set temperature, the set temperature may be used instead of the hot water outlet temperature to calculate the number. For example, the amount of water input is 24 liters / minute and the temperature of hot water is 40
When the water temperature is 15 ° C and the inlet water temperature is 15 ° C, the combustion capacity of the water heater is given as No. 24 by the above formula. Thus, given the number of combustion capacity, the appropriate flow rate suitable for that number is given by the following equation. Appropriate flow rate (liter / min) = number x 25 / (set temperature (° C) -inlet temperature (° C)). In the combustion operation of the water heater, the combustion control is performed so that the hot water of the set temperature is discharged by passing the appropriate flow rate with the given maximum combustion capacity. In addition, when obtaining the appropriate flow rate, the hot water outlet temperature may be used instead of the set temperature.

When the combustion capacity is given as a specification value, the control apparatus 14 is set with combustion capacity characteristic data and combustion air volume characteristic data as shown in FIG. As shown in (a) of the same figure, the combustion capacity characteristic data includes a combustion capacity characteristic line L ₁ for a small capacity and a large capacity on a graph in which the horizontal axis represents the operation amount of fuel supply and the vertical axis represents the combustion capacity. It is a drawing of the combustion capacity characteristic line L ₂ for capacity, and both the capacity lines L ₁ and L ₂ are variable within the range of the operation amount of 0% to 100% to freely control the gas supply amount. It functions as linear characteristic data.

Further, FIG. 5 (b) shows the combustion air flow rate characteristic data, and the capacity line L _{1 is} plotted on a graph in which the horizontal axis shows the operation amount of combustion supply and the vertical axis shows the air flow rate (fan rotation speed). The air flow rate characteristic line M ₁ corresponding to and the air flow rate characteristic line M ₂ corresponding to the capacity line L ₂ are drawn, and the combustion amount is matched by varying the operation amount within the range of 0% to 100%. The produced air volume is supplied to the burner 7.

Incidentally, ignition operating points E ₁ and E ₂ are given to the combustion performance characteristic data and the combustion air flow rate characteristic data, respectively. The ignition operating points E ₁ and E ₂ are the operating points of ignition at which the optimum gas supply amount and the air flow amount at the time of ignition of the burner 7 are given.

The operation amount of fuel supply shown in FIG. 5 corresponds to the opening amount of the gas proportional valve 13, and the capacity switching solenoid valve 45.
In the operating state of small combustion capacity with the closed
The valve opening drive current of the gas proportional valve 13 is set so that the gas supply amount corresponding to the combustion capacity of the point B is supplied to the burner 7 at the position of%, and the combustion capacity of the point A of the combustion capacity at the position of the operation amount 0%. The valve opening drive current of the gas proportional valve 13 is set so that the gas supply amount corresponding to the combustion capacity is supplied to the burner 7.

Similarly, at the time of large capacity combustion operation in which the capacity switching solenoid valve 45 is opened, the operation amount 100% and the capacity line L ₂
The gas supply amount corresponding to the combustion capacity at point D is 0%
At the position where the operation amount is 100% and the operation amount is 0 so that the gas supply amount corresponding to the combustion capacity at point C is supplied to the burner 7, respectively.
The valve opening drive current at the position of% is set respectively.
The valve opening amount of the gas proportional valve 13 is proportional to the magnitude of the valve opening drive current, the magnitude of the valve opening drive current changes according to the magnitude of the operation amount, and the gas amount according to the operation amount is the burner. 7 is supplied. Similarly, the rotation speed of the combustion fan 5 is controlled according to the magnitude of the operation amount, and the air volume suitable for the combustion amount is supplied according to the operation amount.

In this type of capacity switching type water heater, when the combustion operation is performed at the point B along the capacity line L ₁ , when the combustion capacity larger than the combustion capacity at the point B is required, the capacity is increased. jumps to S _a point of the line L _2, the combustion operation is performed according to the capabilities line L _2. On the contrary, when the combustion operation is performed at the point C of the capacity line L ₂ , when a smaller combustion capacity is required, the capacity line L ₁
To point S _b, and the combustion operation is performed according to the capacity line L ₁ .

[0013] Normally, a portion to fly S _a point of capacity line L ₂ from the point B of the capacity line L _1, the part to fly from point C of capacity line L ₂ to S _b point capabilities lines L _1, overlap The generations X ₁ and X ₂ are given, and the ability line L ₁ and
The jump between L ₂ is performed smoothly.
If the overlap margins X ₁ and X ₂ are not provided, for example, when jumping from the capacity line L ₁ to the capacity line L ₂ , if the combustion capacity delicately fluctuates and decreases due to water pressure fluctuations or the like, the capacity line is immediately reduced. Jump from L ₂ to L ₁ ,
That flow back and forth frequently between capacity lines L _1, L ₂ each time fluctuate, so-called, there is a problem that hunting phenomenon occurs, as shown in FIG. 5, the line L _1, L
By skipping the provision of the over-lapping X _1, X ₂ of the shift between the _2, it is possible to smoothly switching capacity line L _1, L _2.

[0014]

However, when a hot water heater is installed at the destination and the combustion operation is to be performed,
If the gas supply pressure (primary pressure) in the area is lower than the predicted range, the previously set FIG.
The combustion performance characteristic data shown in Fig. 3 does not fit the actual situation, and as shown in Fig. 3, where it should be the line characteristic of AB and CD, in reality, as shown by the lines of AQ ₁ B'and CQ ₂ D ' There is a problem that the characteristic line goes to sleep on the side where the operation amount becomes large.

FIG. 7 shows the governing characteristics of the gas proportional valve 13. The horizontal axis of this figure shows the gas supply pressure (primary pressure) in the area where the water heater is installed, that is, the gas pressure P ₁ on the input side of the gas proportional valve 13, and the vertical axis shows that of the gas proportional valve 13. The pressure on the output side, that is, the pressure (secondary pressure) P ₂ supplied to the burner 7 is shown. As the specifications of the gas proportional valve 13, the minimum primary pressure and the maximum primary pressure are given to both sides of the primary pressure P _{1 based} on the standard primary pressure, and the operation amount is 0% of the minimum operation amount to 100 of the maximum operation amount. When the manipulated variable is varied within the range of%, the secondary pressure P _{2 at} each manipulated variable is set to be flat in the section between the minimum primary pressure and the maximum primary pressure, and the primary pressure P ₁ is the minimum. Even if there is a variation between the primary pressure and the maximum primary pressure, the secondary pressure P ₂ is designed so that a constant pressure corresponding to each manipulated variable can be obtained.
As shown in (a) of Fig. 4, as long as the primary pressure is within the range of the minimum primary pressure and the maximum primary pressure, the lines L ₁ and L ₂ of the combustion capacity characteristic are normal within the operation amount range of 0% to 100%. A linear characteristic with a large inclination is obtained, and a suitable combustion operation is secured.

However, when the primary pressure in the area where the water heater is installed is lower than the minimum primary pressure of the covering characteristics, for example, as shown in FIG. Driving, the maximum secondary pressure corresponding to the maximum combustion capacity that should be originally output cannot be obtained, resulting in a secondary pressure lower by ΔP, and only the secondary pressure P _{2 of the} original operation amount of about 80%. In the example of this figure, the secondary pressure of 80% or more of the original operation amount cannot be obtained. In this way, when the actual primary pressure falls below the minimum primary pressure given by the covering characteristics, at the actual primary pressure, the water heater is actually operated because it deviates from the flat region of the covering characteristic line at each manipulated variable. Then, as described above, the combustion ability characteristic is in the region where the manipulated variable is large, as shown in FIG.
The characteristic line is in a lying state, and in the lying state, the combustion ability cannot be increased even if the manipulated variable is increased.

Therefore, for example, even if the combustion operation is performed with the operation amount of 100%, only the combustion capacity of the original operation amount of about 80% is obtained, but on the combustion fan 5 side, the gas proportional valve 13 Since the fan is rotated at 100% of the operation amount according to the operation amount, the air volume commensurate with the original operation amount of 100% gas is supplied even though only the operation amount of 80% of the fuel is actually supplied. As a result of being supplied, there is a problem that excess air is generated and combustion performance deteriorates.

[0018] The present inventors, in order to solve such a problem, as shown in FIG. 3, the combustion capacity characteristic line L _1, L
Suggests a way to update ₂ . According to this proposed method, the combustion capacity is updated by the combustion operation, and when the gas supply pressure in the area where the water heater is installed falls below the predicted range, the capacity line AB is changed to AQ ₁ B ′. Detected as a line, and the CD capability line L ₂ is CQ
Detected as a line of ₂ D ', these capabilities line L _1,
The points at which the slope of L ₂ lies are detected as saturation points Q ₁ and Q ₂ ,
The capacity line L ₁ is within the range of AQ ₁ , that is, the operation amount is 0.
Update configured to use a range of LV ₁ from%, also the ability line L ₂ in the range of CQ _2, that is, is to update set as a line that is limited to a range from the operation amount of 0% LV _2. By doing so, the capacity lines L ₁ and L ₂ both have linearity, and by using the updated capacity lines L ₁ and L ₂ , the combustion amount is matched without excess air. The air volume is supplied to the burner 7, and good combustion operation can be ensured.

However, as described above, the capacity line L
_1, when the L ₂ updated set, combustion capability for Q ₁ point capability line L ₁ is smaller than the combustion capability of the point C of the capacity line L _2, the overlap area between the Q _1, C When it burns at the Q ₁ point of the capacity line L ₁ , and when a larger combustion capacity is required, there is no point to jump from the Q ₁ to the capacity line L ₂ , and likewise. , Point C of ability line L ₂ to ability line L ₁
I faced the new problem that the ability to switch between the ability line L ₁ and the ability line L ₂ could not be switched because there was no point to jump to the side.

The present invention has been made to solve the above problems, and an object of the present invention is to make a jump over between the capacity lines L ₁ and L ₂ by updating and setting the combustion capacity line. It is an object of the present invention to provide a capacity-switching combustion device that can smoothly switch between capacities L ₁ and L ₂ even when the lap region is exhausted.

[0021]

In order to achieve the above object, the present invention is constructed as follows. That is, the present invention, the combustion heating means of the fluid to be heated passing through the heat exchanger,
A flow rate control means for controlling the flow rate of the fluid to be heated and a fuel supply control means for controlling the amount of fuel supplied to the combustion heating means are provided. Between the upper and lower combustion capacity characteristic lines, and the lower side of the combustion capacity characteristic line with the larger capacity, jump between the lines and select the combustion capacity characteristic line according to the required combustion capacity. Then, in the capacity switching type combustion device that drives the combustion heating means to burn according to the selected combustion capacity characteristic line and raises the temperature of the fluid to be heated to the set temperature, the required combustion is judged by switching the combustion capacity characteristic line during combustion operation. A capacity line determination unit that specifies the combustion capacity characteristic line of the switching destination according to the capacity, and a jumping part of the combustion capacity characteristic line on one side that is currently adjacent Side of the combustion capacity characteristic line on the side, the ability line lap determination unit that determines whether there is an overlap margin of combustion ability between the jump arrival portion and this ability line lap determination unit determines that there is no overlap margin. If the combustion capacity of the void portion without the overlap margin is required, the flow rate of the fluid to be heated is reduced to lower the combustion capacity and the jump of the combustion capacity characteristic line is stopped. When the heating fluid is heated to a set temperature and combustion is controlled, and when a request to increase the flow rate of the fluid to be heated is detected in this combustion state, the combustion capacity characteristic line in use jumps to the combustion capacity characteristic line with a larger combustion capacity. If a combustion performance characteristic that is smaller than the flying portion below the combustion performance characteristic line is required, the flow rate of the fluid to be heated is reduced to reduce the combustion performance before It is configured as characterized by having a capacity line switching cushioning movement unit for switching jump over the depleted portion without flop margin to a smaller combustion capability characteristic line of more capable.

[0022]

In the present invention having the above-described structure, for example, when the combustion operation is performed in accordance with the combustion capacity characteristic line on the small capacity side, a combustion capacity larger than the combustion capacity on the upper side of the combustion capacity characteristic line is required. , The capacity line lap determination unit determines whether or not there is an overlap margin with the combustion capacity line at the jump destination, and when it is determined that there is an overlap margin, the line with the larger capacity is normally used. Jump. If it is judged that there is no overlap margin, the flow rate of the fluid to be heated is reduced and the combustion ability is lowered so that the fluid to be heated is heated and burned to the set temperature, and jumping switching of the capacity line is stopped. Combustion operation is performed in this state.

When a request to increase the flow rate of the fluid to be heated is detected in this combustion operation state, it is judged that the combustion capacity beyond the void portion without overlap margin is required, and the combustion performance is ranked one rank higher. Jumps to the lower side of the upper combustion capacity characteristic line and performs the combustion operation according to the combustion capacity characteristic line of the jump destination.

When the combustion operation is performed according to a predetermined combustion capacity line, and when a combustion capacity smaller than the lower end side of the capacity line is required, the flow rate is reduced and the small combustion exceeding the void portion to the lower side. After setting the capacity state, the combustion capacity characteristic line is switched by jumping to the upper end side of the combustion capacity characteristic line one rank below.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. The combustion apparatus of the present embodiment is intended for the water heater having the system configuration shown in FIG. 6, the same name parts as those shown in FIG. 6 are designated by the same reference numerals, and the duplicate description thereof will be omitted. . FIG. 1 shows a block diagram of a control circuit according to the combustion apparatus of the present invention. The control circuit of this embodiment includes a combustion capacity calculation unit 20, a proportional valve operation amount calculation unit 21, a proportional valve drive unit 22, a temperature deviation detection unit 23, and a set flow rate calculation unit.
24, a flow rate deviation detection unit 25, a capacity update condition monitoring unit 26 that functions as a capacity update determination command unit, timers 27 and 39, a correction flow rate integration unit 28, a correction flow rate storage unit 29, and a capacity update calculation unit. 30, a water amount control valve operation amount calculation unit 31, a water amount control valve drive direction determination unit 32, a water amount control valve drive unit 33, a water amount control valve fully open / fully closed detection unit 34, an initial data storage unit 35, Update data storage unit 36, fan operation amount calculation unit 37, fan drive unit
38, ability line determination unit 40, ability line wrap determination unit
41 and a capacity line switching buffer operation unit 42.

In the initial data storage unit 35, the value of the hot water supply combustion ability determined at the design stage according to the specifications of the water heater is stored as, for example, No. 24, and further, the combustion ability characteristic data as shown in FIG. 5 which is determined by this combustion ability. And the combustion air flow rate characteristic data is stored.

Combustion capacity calculation unit 20 and proportional valve operation amount calculation unit
21, the proportional valve drive unit 22, the temperature deviation detection unit 23, the fan operation amount calculation unit 37, the fan drive unit 38 is a circuit of a portion for performing a normal combustion control, to briefly describe this, first, ,
The combustion capacity calculation unit 20 stores the temperature information set by the temperature setting unit such as the remote controller 15, the information of the incoming water temperature detected by the incoming water thermistor 10, and the flow rate detection value detected by the flow rate sensor (flow sensor) 9. Upon receiving the information, further, by receiving the detection information of the deviation between the hot water temperature detected by the temperature deviation detection unit 23 and the set temperature, the amount of combustion heat (combustion capacity) required to raise the incoming water temperature to the set temperature is calculated. The calculation result is added to the proportional valve operation amount calculation unit 21.

The proportional valve operation amount calculation unit 21 is a combustion capacity calculation unit.
The manipulated variable for obtaining the combustion ability calculated in 20 is calculated, and this value is added to the proportional valve drive unit 22. The proportional valve drive unit 22 applies the valve opening drive current corresponding to the operation amount calculated by the proportional valve operation amount calculation unit 21 to the gas proportional valve 13 to add the gas proportional valve 13
The valve opening amount, that is, the gas supply amount is controlled. On the other hand,
The fan operation amount calculation unit 37 calculates the operation amount of the fan rotation of the combustion fan 5 corresponding to the magnitude of the combustion heat amount calculated by the combustion capacity calculation unit 20, and calculates the calculated fan operation amount. Add to 38. The fan drive unit 38 rotationally drives the combustion fan 5 according to the operation amount added from the fan operation amount calculation unit 37. As a result, an air volume matching the amount of gas supplied to the burner 7 is supplied, and good burner combustion is performed.

The set flow rate calculating section 24 calculates an appropriate flow rate corresponding to the combustion capacity of the water heater. This suitable flow rate is obtained by the following equation as described above.

Appropriate flow rate (liter / minute) = number of items x 25 /
(Set temperature (℃) -Inlet temperature (℃))

For example, the set temperature is 48 ° C. and the incoming water temperature is 13
Calculating the proper flow rate when the combustion capacity is 24 ° C, it is about 17
Calculated as liters / minute.

The flow rate deviation detecting section 25 compares the detected flow rate obtained from the flow rate sensor 9 with the appropriate flow rate obtained by the set flow rate calculating section 24, detects the flow rate deviation, and outputs the detection result as the capacity update condition. Monitoring unit 26 and water amount control valve operation amount calculation unit
Add to 31.

A condition for judging whether or not to perform the capability update calculation is preset in the capability update condition monitoring unit 26, and when the condition is satisfied, the capability update calculation is instructed. As a determination material of whether or not the temperature deviation range between the set temperature and the hot water temperature, a flow rate deviation range between the detected flow rate and the appropriate flow rate, and the like are given in advance. For example, a deviation temperature range of ± 0.5 ° C. with respect to the set temperature and a flow deviation range of ± 0.1 liter with respect to an appropriate flow rate are given.

The capacity update condition monitoring unit 26 causes the hot water outlet temperature to fall within the temperature deviation range (and if necessary, the detected flow rate to fall within the flow deviation range), and that state is maintained for a predetermined time given in advance. When this is confirmed, a capacity update calculation command is added to the capacity update calculation unit 30. When the flow rate is not within the flow rate deviation range, information to that effect is added to the corrected flow rate integrating section 28.

The water amount control valve fully open / fully closed detection unit 34 detects when the water amount control valve 16 is in the fully open state and when the water amount control valve 16 is in the fully closed state, and the detection result is detected by the capacity update condition monitoring unit 26 and the water amount control valve. The operation amount calculation unit 31 is added.

The water amount control valve operation amount calculation unit 31 receives the detection result from the flow rate deviation detection unit 25, and when the detected flow amount deviates from the flow amount deviation, calculates the operation amount in the direction in which the detected flow amount approaches the proper flow amount. The calculation result is added to the water amount control valve drive direction determination unit 32.

The water amount control valve drive direction determination unit 32 receives information from the water amount control valve operation amount calculation unit 31 and the opening / closing drive direction of the water amount control valve and the operation calculated by the water amount control valve operation amount calculation unit 31. The quantity value is added to the water quantity control valve drive unit 33. The water volume control valve drive unit 33 controls the opening amount of the water volume control valve 16 based on the information added from the water volume control valve drive direction determination unit 32. The correction flow rate integration unit 28 integrates the correction amount of the guess control that is momentarily controlled during the combustion operation of the water heater, and stores the integration result in the correction flow rate storage unit 29.

The capability update calculation unit 30 is a capability update condition monitoring unit.
When the capacity update command is received from 26, using the values of the incoming water temperature, the hot water temperature, and the flow rate (the flow rate obtained by the set flow rate calculation unit 24 corrected by the correction flow rate), the above-mentioned number is calculated. The combustion capacity is calculated using the calculated formula, the combustion capacity characteristic data is updated, and the updated data is stored in the update data storage unit 36. When this update data is stored, the next combustion operation is performed according to the update data.

The capacity line determination unit 40 is the combustion capacity calculation unit 20.
Depending on the magnitude of the required combustion capacity calculated in step _1, which of the capacity lines L ₁ and L ₂ of the combustion capacity characteristic data is to be used is determined, for example, when combustion is performed using the capacity line L ₁ . When a capacity exceeding the capacity line L ₁ is requested to the capacity line L ₂ , a jump is commanded to the capacity line L _2, and when combustion is performed using the capacity line L ₂ , when a capacity smaller than the capacity line L ₂ is requested. , L ₂ to L ₁ command.

The capacity line lap judgment unit 41 judges whether or not there is an overlap margin between the capacity lines L ₁ and L ₂ of the updated combustion capacity characteristic data, by the capacity update of the capacity update calculation unit 30. Then, the result is added to the capacity line switching buffer operation unit 42.

When the capacity line switching / buffering section 42 receives a jump command from the capacity line L ₁ to the capacity line L ₂ , the capacity line wrap judging section 41 judges by the judgment result.
If it is found that there is a gap between the performance lines L ₁ and L ₂ with no overlap margin, the performance line L
Without immediately jumping from ₁ to L ₂ , the water amount control valve 16 is once throttled by a predetermined amount to slightly reduce the combustion capacity to temporarily prevent the jump from the capacity line L ₁ to L ₂ . Then, the water amount control of the water amount control valve 16 is stopped to detect whether or not the water amount is increased. This increase in water amount is detected even if the water amount control valve 16 stops the water amount control.
When the hot water tap 1 is further opened (in this case, the load resistance is small) or the water pressure is increased, the water amount is increased, which is detected by the flow rate sensor 9 or the like and the flow rate increase request is made. To detect.

When the request for increasing the amount of water is recognized, the capacity line switching buffer operation unit 42 determines that the increase in combustion capacity is definitely requested, and the Q ₁ point of the capacity line L ₁ shown in FIG. 3 is determined. To the point C of the ability line L ₂ and the ability line L ₁ is switched to L ₂ . Then, after the switching, the timer 39 is operated for a predetermined time to judge the stable state of the hot water temperature, and when there is no decrease in the hot water temperature, the water quantity control valve 16 is gradually opened in accordance with the capacity line L ₂ to make a request. The amount of water that can be used is output. When there is reduction in the temperature of hot water immediately after moved flew to the point C from Q ₁ point, back to Q ₁ point again from point C is determined not to be a state of increasing the combustion capability, the combustion operation in accordance with capacity line L ₁ Let it continue. When a combustion capacity smaller than the point C is required in the combustion operation according to the capacity line L ₂ , the water amount control valve 16 is throttled to decrease the combustion capacity, and then the point C is jumped to the point Q _1. Then, the combustion operation is performed according to the capacity line L ₁ .

This embodiment is constructed as described above,
Next, the operation of the combustion apparatus of this embodiment will be described based on the flowchart of FIG. First, when the hot water supply operation is commanded by the remote controller 15 and combustion is started when an ON signal is applied from the flow sensor (flow rate sensor) 9, when the hot water supply apparatus is installed and constructed, the initial data storage unit 35 of the initial data storage unit 35 is used for the first operation. After performing a data check and checking the data stored in the update data storage unit 36 for the second and subsequent combustion operations, the set temperature T _SP , the incoming water temperature TM _IN, and the flow rate FW are read in step 204, and the step The required combustion capacity is calculated at 205. The calculation of the combustion ability is performed using the arithmetic expression for obtaining the above-mentioned number.

Next, at step 206, the capability lines L ₁ and L
_It is determined whether there is an overlap allowance between the _two . If it is determined that there is an overlap allowance, step
At 222, the set temperature is compared with the hot water temperature, and it is determined whether the hot water temperature is within the temperature deviation range of the set temperature. If it is within the temperature deviation range, the combustion operation is continued as it is.If the tap water temperature is not within the temperature deviation range, the combustion control in step 223 and the water amount control in step 224 are performed to make the tap temperature equal to the set temperature. The capacity line currently in use will be updated.

In step 206, the capacity lines L ₁ and L ₂
It is judged that there is no overlap margin with
_When a change command from ₁ to L ₂ is issued, at the position of the combustion capacity at the Q ₁ point of the capacity line L ₁ , the water quantity control valve 16 throttles the water quantity by a predetermined amount (α) to slightly reduce the combustion capacity,
Combustion control is performed as it is on the capacity line L ₁ . Then, in step 210, it is judged whether or not the outlet heated water temperature is within the temperature deviation range of the set temperature, and if it is not within the temperature deviation range, the operations of steps 208 to 210 are repeated and the outlet heated water temperature is within the temperature deviation range. To control. When the outlet heated water temperature is within the temperature deviation range and the outlet heated water temperature and the set temperature are substantially equal to each other, the control of the water amount control valve 16 is stopped in step 212 after confirming the stable state of the flow rate.

Next, at step 213, it is judged from the detection signal of the flow rate sensor whether or not the increase in the amount of water is required due to, for example, the hot water tap 1 being further opened or the water pressure being increased, as shown in FIG. When an increase in the amount of water is recognized, the timer 39 is used to detect the increase in the amount of water.
₁ second, stable capacity line L ₁ make sure that that Q ₁
From the point to the point C of the ability line L ₂ , the ability line is switched from L ₁ to L ₂ . And step 216
Then, the timer 39 waits for t ₂ seconds to elapse, and in step 217, it is judged whether or not the hot water temperature has dropped.

If a decrease in the tap water temperature is recognized, it is judged that the request for increasing the combustion capacity is not appropriate, and the amount of water is reduced in step 208 to decrease the combustion capacity.
_Return from ₂ to L ₁ and perform combustion operation. If it is found in step 217 that the tapping temperature has not dropped and the tapping temperature is within the temperature deviation range of the set temperature, the water volume control valve 16 is driven to set the tapping temperature in order to meet the request for an increase in the flow rate. While confirming that the temperature is within the temperature deviation range, the total water amount increases until it reaches the proper water amount FW _SP , and when the water flow amount reaches the proper water amount, or the water amount control valve 16 is fully opened. When it becomes, the combustion operation is continued by the operation after step 222.

According to this embodiment, the capacity lines L ₁ and L ₂
There is no overlap margin with and both ability lines L ₁ ,
Even when a gap is generated between L ₂ , the ability line lap determination unit 41 and the ability line switching buffer operation unit 42 can switch the ability lines L ₁ and L ₂ without any trouble. Become.

Therefore, the water heater is used in an area where the gas supply pressure is out of the predicted range and has a low pressure, and the combustion capacity characteristic data is updated.
Even if there is a void portion between ₁ and L _2, the capacity lines L ₁ and L ₂ can be switched according to the required heat amount, and a water heater with good usability can be provided.

The present invention is not limited to the above-mentioned embodiment, but can take various modes. For example, the two-stage switching example has been described as the capacity switching type burner, but the present invention is also applied to the case where a three-stage switching type burner is used. In the case of capacity switching of three or more stages, capacity characteristic lines corresponding to the number of stages are given, and when there is no overlap margin between each capacity characteristic line, switching between capacity lines is performed by the same operation as in the above embodiment. Will be done.

Further, in the above embodiment, the capacity line L ₁
When switching from L ₂ to L ₂ , once the flow rate is narrowed and the increase in flow rate is detected in the capacity line L ₁ , the increase in flow rate is detected based on the signal from the flow rate sensor 9, but this is detected by the pressure sensor or the tap water thermistor 11. May be detected. At the time of detecting this increase in the flow rate, the water volume control valve 16 is in a state in which the water volume control is stopped. In this state, it is confirmed that the load water pressure decreases when the hot water tap 1 is further opened. An increase in the flow rate can be detected by detecting it. Further, as shown in FIG. 4, when the amount of water is increased, the outlet heated water temperature is lowered, so that the decrease in the outlet heated water temperature can be detected to detect the increase in the flow rate.

Furthermore, in each of the above-mentioned embodiments, the hot water supply device has been described as the combustion device, but the present invention is applicable to other combustion devices such as an air conditioner for heating or cooling by using gas or oil as a fuel, or a bath cooker. Also applies to.

[0053]

According to the present invention, when switching of the combustion capacity characteristic line is instructed during the combustion operation, there is an overlap margin between the combustion capacity characteristic line being used and the combustion capacity characteristic line of the switching destination. It is determined whether or not there is, and when there is a void portion without overlap margin, the capacity line switching buffer operation unit is configured to smoothly switch the combustion capacity characteristic line. Even if the fuel supply pressure is out of the expected range and is low, and the combustion capacity line is updated to match the actual situation of actual operation, and there is a gap between the capacity lines that does not have an overlap margin, there is a problem. It is possible to switch the combustion capacity line without any need, and it is possible to perform a suitable combustion operation.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a control circuit of a combustion device according to the present invention.

FIG. 2 is a flow chart showing the operation of the embodiment.

FIG. 3 is a graph showing both initial data and updated data of a combustion capacity characteristic line of a capacity switching type combustion device.

FIG. 4 is a graph showing the relationship between the set temperature and the amount of water when switching between the combustion performance characteristic lines in the present embodiment.

FIG. 5 is an explanatory diagram of a combustion capacity characteristic line provided to a general capacity switching type combustion apparatus.

FIG. 6 is a system configuration diagram of a general capacity switching type water heater.

FIG. 7 is a governing characteristic diagram of a gas proportional valve used in a water heater.

FIG. 8 is an explanatory diagram of a defective state when the supply gas pressure of the water heater is outside the predicted range and is low.

[Explanation of symbols]

 14 Control device 16 Water flow control valve 20 Combustion capacity calculation section 30 Capacity update calculation section 40 Capacity line determination section 41 Capacity line lap determination section 42 Capacity line switching buffer operation section

Claims (1)

[Claims] 1. A combustion heating means for heating a heated fluid passing through a heat exchanger, a flow rate control means for controlling a flow rate of the heated fluid, and a fuel supply control means for controlling an amount of fuel supplied to the combustion heating means. In addition, multiple combustion capacity characteristic lines are provided depending on the combustion capacity range, and there is a jump between lines on the upper side of the adjacent combustion capacity characteristic line with smaller capacity and the lower side of the combustion capacity characteristic line with larger capacity. Perform a capacity-switching combustion that selects the combustion capacity characteristic line according to the required combustion capacity by jumping, drives the combustion heating means according to the selected combustion capacity characteristic line, and raises the temperature of the fluid to be heated to the set temperature. In the device, a capacity line determination unit that determines the switching of the combustion capacity characteristic line during combustion operation and specifies the combustion capacity characteristic line of the switching destination according to the required combustion capacity, and A capacity line lap determination unit that determines whether or not there is an overlap margin of combustion capacity between the jumping-out portion of the combustion capacity characteristic line on the one side and the jumping arrival portion of the combustion capacity characteristic line on the other side that are adjacent to each other. , If the capacity line lap determination unit determines that there is no overlap allowance and the combustion capacity of the void portion where there is no overlap allowance is requested, the combustion capacity is reduced by reducing the flow rate of the fluid to be heated. Lowering combustion capability characteristic The jumping of the line is stopped and the fluid to be heated is heated to a set temperature to perform combustion control.In this combustion state, the combustion in use is detected when a request to increase the flow rate of the fluid to be heated is detected. Jump from the capacity characteristic line to the combustion capacity characteristic line with a larger combustion capacity,
When a combustion capacity characteristic smaller than the flying portion below the combustion capacity characteristic line is required, the flow rate of the fluid to be heated is reduced to reduce the combustion capacity, and then the air gap with no overlap margin is jumped over to improve the capacity. A capacity switching type combustion apparatus having a capacity line switching buffer operation unit for switching to a small combustion capacity characteristic line.