JP3322977B2 - Capacity switching type combustion 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 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 general water heater as a capacity switching type combustion device. In the figure, a water supply pipe 3 for water as a fluid to be heated is connected to the inlet side of the heat exchanger 2. The water supply pipe 3 has an input water thermistor 10 as input temperature detection means for detecting the input water temperature.
And a flow rate sensor 9 of a flow rate detecting means for detecting the amount of incoming water. A hot water supply pipe 4 is connected to an outlet side of the heat exchanger 2, and a hot water tap 1 is provided at an outlet side of the hot water supply pipe 4. Further, the hot water supply pipe 4 has a water flow control valve 16 as flow control means whose valve opening is controlled by a gear motor,
A tapping thermistor 11 is provided as tapping temperature detecting means for detecting tapping temperature.

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

A water heater of this type 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 section such as a button for setting a hot water temperature and a hot water setting. A temperature display is provided. The control device 14 controls the hot water supply operation of the water heater, and when the hot water tap 1 is opened, the flow sensor 9 detects the amount of incoming water, and when the amount of incoming water becomes a certain value or more (the minimum operating flow or more). The controller 14 rotates the combustion fan 5 in response to the signal from the flow sensor 9. 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 gas to the burner 7, and the igniter electrode 18 performs an ignition operation. Frame rod electrode 19
When the controller detects gas ignition, the control device 14 performs feedforward control so that the tap water temperature is set to the set temperature, changes the valve opening amount of the gas proportional valve 13, and adjusts the hot water temperature exiting the heat exchanger 2 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.

[0005] As is well known, a hot water supply device is provided with a hot water supply combustion capability, and the hot water supply device performs combustion control so as to set a tapping temperature to a set temperature within the range of the combustion capability. The combustion capacity given to a water heater is given by the number,
The symbol refers to the combustion capacity required to raise one liter of water per minute by 25 ° C.

[0006] That is, the number of water = water input (liter / minute) x
｛Outlet water temperature (° C)-Inlet water temperature (° C)｝ ÷ 25 Since the tapping temperature is equal to the set temperature, the number may be calculated using the set temperature instead of the tapping temperature. For example, if the water input is 24 liters / minute and the tap water temperature is 40
When the water temperature is 15 ° C. and the water inlet temperature is 15 ° C., the combustion capacity of the water heater is given as No. 24 by the above equation. Thus, when the number of the combustion capacity is given, an appropriate flow rate suitable for the number is given by the following equation. Appropriate flow rate (liter / min) = number × 25 / (set temperature (° C)-incoming water temperature (° C)). In the combustion operation of the water heater, the combustion control is performed so that the appropriate flow rate is supplied with the given maximum combustion capacity to discharge hot water at a set temperature. In addition, when determining an appropriate flow rate, a tapping temperature may be used instead of the set temperature.

When the combustion capacity is given as a specification value, the control unit 14 is set with combustion capacity characteristic data and combustion air volume characteristic data as shown in FIG. Combustion capacity characteristic data, as shown in FIG. (A), the horizontal axis represents the amount of operation of the fuel supply, a combustion capacity characteristic line L ₁ for a small capacity and the vertical axis on the graph that the combustion capability, large but depicting a combustion capacity characteristic line L ₂ for ability, by varying in the range of 100% from the capacity line L _1, L ₂ are both operation amount of 0%, is variably controlled freely gas supply amount Functions as linear characteristic data.

Furthermore, the (b) is 5, shows a combustion air volume characteristic data, the operation amount of combustion supplied to the horizontal axis, the ability to vertical axis air volume on a graph taking the (fan speed) lines L ₁ the air volume characteristic line M ₁ corresponding to, which depicts the air volume characteristic line M ₂ corresponding to the capacity line L _2, by varying in a range from the operation amount of 0% to 100%, matching the combustion quantity The blown air volume is supplied to the burner 7.

The ignition performance points E ₁ and E ₂ are given to the combustion performance characteristic data and the combustion air volume characteristic data, respectively. The ignition operation points E ₁ and E ₂ are ignition operation points that provide an optimum gas supply amount and an air flow when the burner 7 is ignited.

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

[0011] Similarly, during combustion operation of the large capacity opened the capability switching solenoid valve 45, capacity line L ₂ by the operation amount 100%
The gas supply amount corresponding to the combustion capacity at point D is 0%
In order to supply the gas supply amount corresponding to the combustion capacity at the point C to the burner 7, the position of the operation amount 100% and the operation amount 0
The valve opening drive current at the% position is set respectively.
The 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 in accordance with the magnitude of the operation amount, and the gas amount corresponding to the operation amount is 7 is supplied. Similarly, the number of rotations of the combustion fan 5 is controlled by the magnitude of the operation amount, and an air flow suitable for the combustion amount is supplied by the operation amount.

[0012] In water heater capacity switchable of this kind, when doing the combustion operation at point B along the ability line L _1, when a large combustion capacity than the combustion capability of the point B is requested, the ability 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 doing the combustion operation at point C of capacity line L _2, when smaller combustion capability is required, the capacity line L ₁
Flew to the S _b point, the combustion operation is performed according to the capabilities 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 generation X _1, X ₂ has been given, capacity line L _1,
Hopping between the L ₂ is adapted to be carried out 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 fluctuates slightly due to fluctuations in water pressure and the like, the capacity line is immediately reduced. move 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 providing the overlap margins X ₁ and X ₂ that jump between the _two , the ability lines L ₁ and L ₂ can be switched smoothly.

[0014]

However, when a water heater is installed at a destination and a 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 match the actual condition, and as shown in FIG. 3, the line characteristics should be originally AB and CD, but actually, as shown by the lines AQ ₁ B ′ and CQ ₂ D ′. There is a problem that the characteristic line falls down on the side where the operation amount increases.

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 the gas proportional valve 13 the pressure on the output side, that is, an pressure supplied to the burner 7 (secondary pressure) P _2. As a specification of the gas proportional valve 13, as a primary pressure P ₁ is based on the standard primary pressure, and the minimum primary pressure and the maximum primary pressure is applied on both sides, of the maximum operation amount of the operation amount of 0% to a minimum operation amount 100 %, When the manipulated variable is varied in the range between the minimum primary pressure and the maximum primary pressure, the secondary pressure P ₂ for each manipulated variable is set to be flat, and the primary pressure P ₁ is minimized. The secondary pressure P ₂ is designed so that a constant pressure corresponding to each manipulated variable can be obtained even if the pressure varies between the primary pressure and the maximum primary pressure.
As shown in (a), 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 range of the operation amount 0% to 100%. It has a linear characteristic with an appropriate inclination, and a suitable combustion operation is ensured.

However, when the primary pressure in the area where the water heater is installed is lower than the minimum primary pressure of the governing characteristic, for example, as shown in FIG. , The maximum secondary pressure corresponding to the maximum combustion capacity that should be output is not obtained, and the secondary pressure becomes lower by ΔP, and only the secondary pressure P _{2 of} about 80% of the original operation amount is obtained. Therefore, in the example of this figure, a secondary pressure of 80% or more of the original operation amount cannot be obtained. As described above, when the actual primary pressure falls below the minimum primary pressure given by the governing characteristics, the actual primary pressure deviates from the flat region of the governing characteristic line for each operation amount, so that the water heater is actually operated. Then, as shown in FIG. 3, the combustion capacity characteristic is in the region where the operation amount is large, as described above,
The characteristic line becomes in a lying state, and the combustion capacity cannot be increased in the lying state even if the operation amount is increased.

For this reason, for example, even if the combustion operation is performed with the operation amount of 100%, only the combustion capacity of about 80% of the original operation amount can be obtained. Since the fan rotates at a 100% operation amount in accordance with the operation amount, the air flow corresponding to the original 100% gas supply amount is achieved even though only the 80% operation amount of fuel is actually supplied. As a result, there is a problem that the air becomes excessive and the combustion performance deteriorates.

In order to solve such a problem, the present inventor has set the combustion performance characteristic lines L ₁ and L ₁ as shown in FIG.
Suggests how 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 is lower than the predicted range, the capacity line AB is set to AQ ₁ B ′. detected as a line, also, the ability line L ₂ of the CD CQ
Detected as a line of ₂ D ', these capabilities line L _1,
The points where the slope of L ₂ falls are detected as saturation points Q ₁ and Q ₂ ,
The ability line L ₁ in the range of AQ _1, i.e., an operation amount 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 linearity of both the performance lines L ₁ and L ₂ is ensured, and by using the updated and set performance lines L ₁ and L ₂ , it is possible to match the combustion amount without excess air. The air volume is supplied to the burner 7, and a good combustion operation can be ensured.

However, as described above, the performance 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 will run out, when I was burned by Q ₁ point capability lines L _1, when a large combustion capability is required than that, it will run out of that fly from Q ₁ to capacity line L _2, similarly ability line L ₁ from the point C of capacity line L ₂
Will run out of the point to jump to the side faced to a new problem arises that it becomes impossible capacity switching between capacity lines L ₁ and capacity line L _2.

The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to perform an update setting of a combustion capacity line or the like so that a jump between the capacity lines L ₁ and L ₂ can be made. even when an area of the wrap was gone, to provide a capability switching combustion apparatus capable of performing hopping switching between capacity lines L ₁ and L ₂ smoothly.

[0021]

The present invention is configured as follows to achieve the above object. That is, the present invention provides a means for burning and heating a fluid to be heated passing through a heat exchanger,
A fuel supply control means for controlling a flow rate of the fluid to be heated and a fuel supply control means for controlling an amount of fuel supplied to the combustion heating means, wherein a plurality of combustion performance characteristic lines are provided according to a combustion performance range; Jumps between the lines on the upper side of the combustion performance characteristic line on the smaller side and on the lower side of the combustion performance characteristic line on the higher side, and selects the combustion performance characteristic line according to the required combustion performance by jumping Then, in the capacity switching type combustion apparatus which drives the combustion heating means in accordance with the selected combustion performance characteristic line and raises the temperature of the fluid to be heated to the set temperature, the switching of the combustion performance characteristic line is determined during the combustion operation to determine the required combustion. A capacity line determining unit that designates a combustion capacity characteristic line to be switched to in accordance with the capacity, and a jumping part of the currently adjacent combustion capacity characteristic line and other parts A capacity line wrap determining unit that determines whether there is an overlap margin of the combustion capacity between the jumping arrival part of the combustion performance characteristic line on the side, and the ability line lap determining unit determines that there is no overlap margin. In this case, if the combustion capacity of the empty space without the overlap margin is required, the flow rate of the fluid to be heated is reduced, the combustion capacity is reduced, and the jumping of the combustion performance characteristic line is stopped. The heating fluid is heated to the set temperature to perform combustion control.In this combustion state, when a request to increase the flow rate of the fluid to be heated is detected, the combustion performance characteristic line in use is changed to a combustion performance characteristic line having a larger combustion capability. If a combustion performance characteristic smaller than the rising portion below the combustion performance characteristic line is required, reduce the flow rate of the fluid to be heated, lower the combustion performance, and then Tsu is configured as characterized by having a capacity line switching cushioning movement unit to switch to a smaller combustion capability characteristic line of more capable jumping over the depleted portion without flop allowance.

[0022]

In the present invention having the above structure, for example, when the combustion operation is performed in accordance with the combustion performance characteristic line on the small capacity side, if a combustion capacity larger than the combustion capacity on the upper side of the combustion performance characteristic line is required. Is determined by the capacity line overlap determination unit whether there is an overlap margin with the combustion capacity line of the jump destination, and when it is determined that there is an overlap margin, the line with the larger capacity is used as usual. Jump over. If it is determined that there is no overlap, the flow rate of the fluid to be heated is reduced, and the fluid to be heated is heated and burned to the set temperature in a state where the combustion capacity is reduced, and the switching of the performance line is suppressed. Combustion operation is performed in the state where it is set.

In this combustion operation state, when a request to increase the flow rate of the fluid to be heated is detected, it is determined that the combustion capacity beyond the empty space without an overlap margin is required, and the combustion performance is ranked one rank higher. Jumps to the lower side of the upper combustion performance characteristic line, and performs the combustion operation in accordance with the combustion performance characteristic line of the jump destination.

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

[0025]

Embodiments of the present invention will be described below with reference to the drawings. The combustion device of the present embodiment is intended for a water heater having the system configuration shown in FIG. 6, and the same reference numerals are given to the same components as those shown in FIG. 6, 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 calculating unit 20, a proportional valve operation amount calculating unit 21, a proportional valve driving unit 22, a temperature deviation detecting unit 23, and a set flow rate calculating unit.
24, a flow deviation detection unit 25, a capacity update condition monitoring unit 26 functioning as a capacity update determination command unit, timers 27 and 39, a corrected flow integration unit 28, a corrected flow 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 section 40, ability line lap determination section
41 and a capacity line switching buffer operation section 42.

In the initial data storage unit 35, the value of the hot water combustion capacity determined at the design stage according to the specifications of the water heater is stored as, for example, No. 24. Further, the combustion performance characteristic data as shown in FIG. And combustion air volume characteristic data.

Combustion capacity calculator 20 and proportional valve operation amount calculator
21, a proportional valve drive unit 22, a temperature deviation detection unit 23, a fan operation amount calculation unit 37, and a fan drive unit 38 are circuits for performing a normal combustion control. ,
The combustion capacity calculation unit 20 calculates the temperature information set by the temperature setting unit such as the remote controller 15, the information on the incoming water temperature detected by the incoming water thermistor 10, and the detected flow rate value detected by the flow rate sensor (flow sensor) 9. Receiving the information, and further detecting the deviation between the tapping temperature detected by the temperature deviation detection unit 23 and the set temperature, the amount of combustion heat (combustion capacity) required to increase 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 includes a combustion capacity calculation unit.
An operation amount for obtaining the combustion capacity calculated in 20 is obtained by calculation, and this value is added to the proportional valve drive unit 22. The proportional valve drive unit 22 applies a 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,
, That is, the gas supply amount is controlled. On the other hand,
The fan operation amount calculation unit 37 calculates an 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 obtained fan operation amount by the fan driving unit. 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 flow corresponding to the amount of gas supplied to the burner 7 is supplied, and good burner combustion is performed.

The set flow rate calculator 24 calculates an appropriate flow rate corresponding to the combustion capacity of the water heater. The appropriate flow rate is determined by the following equation as described above.

Appropriate flow rate (liter / min) = number × 25 /
(Set temperature (° C)-Inlet water temperature (° C))

For example, when the set temperature is 48 ° C. and the incoming water temperature is 13
Calculating the appropriate flow rate when the combustion capacity is 24 ° C
It is determined 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 uses the detection result as a capacity update condition. Monitoring unit 26 and water amount control valve operation amount calculation unit
Add to 31.

A condition for determining whether or not to perform the capacity update calculation is set in advance in the capacity update condition monitoring unit 26, and when the condition is satisfied, a capacity update calculation command is issued. The temperature deviation range between the set temperature and the tapping temperature, the flow deviation range between the detected flow rate and the appropriate flow rate, and the like are given in advance as a material for determining whether or not the flow rate is acceptable. For example, a value of ± 0.5 ° C. for a set temperature is given as a deviation temperature range, and a value of ± 0.1 liter is given for an appropriate flow rate as a flow deviation range.

The capacity update condition monitoring unit 26 sets the tapping temperature in the temperature deviation range (and, if necessary, the detected flow rate in the flow deviation range), and this state is maintained for a predetermined period of time. When it is confirmed that this is the case, a command for a capacity update calculation is added to the capacity update calculation unit 30. If the flow rate does not fall within the flow rate deviation range, information to that effect is added to the corrected flow rate integrating section.

The water flow control valve fully open / closed detection unit 34 detects when the water flow control valve 16 is in the fully open state and when it is in the fully closed state, and outputs the detection results to the capacity update condition monitoring unit 26 and the water flow control valve. It is added to the manipulated variable calculator 31.

The water amount control valve operation amount calculation unit 31 receives the detection result from the flow amount deviation detection unit 25, and when the detected flow amount is out of the flow amount deviation, calculates the operation amount in a direction in which the detected flow amount approaches an appropriate 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 judging section 32 receives the information from the water amount control valve operation amount operation section 31, and controls the opening / closing drive direction of the water amount control valve and the operation calculated by the water amount control valve operation amount operation section 31. The value of the amount is added to the water amount control valve driving unit 33.
The water amount control valve driving unit 33 includes the water amount control valve driving direction determination unit 3
Based on the information added from 2, the opening and closing of the opening amount of the water amount control valve 16 is controlled. The correction flow rate accumulating unit 28 accumulates the correction amount of the water amount 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 capacity update calculating section 30 is a capacity update condition monitoring section.
When a capacity update command is received from 26, using the values of the incoming water temperature, the outlet water temperature, and the flow rate (the flow rate obtained by correcting the flow rate obtained by the set flow rate calculation unit 24 with the corrected flow rate), The combustion capacity is obtained using the formula to be obtained, the combustion capacity characteristic data is updated, and the updated data is stored in the update data storage unit 36. When the updated data is stored, the next combustion operation is performed according to the updated data.

The capacity line determination section 40 is provided with a combustion capacity calculation section 20.
In is calculated according to the magnitude of the required combustion capability to determine whether to use the capacity line L ₁ and L ₂ of the combustion capacity characteristic data, for example, when the burning using the capacity line L ₁ commands the interlaced ability line L ₂ when the ability to cross the capacity line L ₁ is requested, when I was combusted using a capacity line L _2, when smaller capacity than capacity line L ₂ is requested , an instruction to jump from L ₂ to L _1.

The capacity line overlap determination section 41 determines 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 section 30. Then, the result is added to the capacity line switching buffer operation section 42.

When receiving the jump command from the performance line L ₁ to the performance line L ₂ , the capability line switching buffering operation unit 42 determines, based on the determination result of the capability line lap determination unit 41,
When it has been found that the sky cut-out portion with no overlap margin between the capacity line L ₁ and L ₂ has occurred, capacity line L
Without causing immediately hopping from ₁ to L _2, once temporarily restrain the jump of the water amount control valve 16 from the ability line L ₁ slightly dropped a predetermined amount squeezed combustion capability to L _2. Then, the water amount control of the water amount control valve 16 is stopped, and it is detected whether or not the water amount has increased. The detection of the increase in the water amount is performed 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 reduced) or when the water pressure is increased, the water amount is increased, and this is detected by the flow rate sensor 9 or the like, and the flow rate increase request is made. Is detected.

[0042] The ability line switching cushioning movement unit 42, when the water amount increase request is granted, it is judged that the combustion capacity of up is reliably requested, Q ₁ point capability line L ₁ shown in FIG. 3 switching the capacity line L ₁ to L ₂ proceeds skips to point C of the capacity line L ₂ from. After the switching, to determine the stability status of the hot water temperature by operating a predetermined time the timer 39, when no observed decrease water temperature in accordance with capacity line L _2, is required to gradually open the water amount control valve 16 Water volume. 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. Further, in a state where the combustion operation according to the capabilities line L _2, when the small combustion capability is required than point C, jumping from point C to Q ₁ point from dropped burning ability squeezing water control valve 16 Utsura allowed to perform the combustion operation in accordance with capacity line L _1.

This embodiment is configured as described above.
Next, the operation of the combustion apparatus of the present embodiment will be described based on the flowchart of FIG. First, the hot water supply operation is instructed by the remote controller 15, and when an ON signal is applied from the flow sensor (flow rate sensor) 9, the combustion starts. A data check is performed, and in the second and subsequent combustion operations, the stored data in the update data storage unit 36 is checked. At step 204, the set temperature T _SP , the incoming water temperature TM _IN, and the flow rate FW are read. At 205, the required combustion capacity is calculated. The calculation of the combustion capacity is performed using the above-described arithmetic expression for calculating the number.

Next, at step 206, the ability lines L ₁ and L
_It is determined whether there is an overlap fee between the _two . If it is determined that there is overlap,
At 222, the set temperature and the tapping temperature are compared, and it is determined whether or not the tapping temperature is within the temperature deviation range of the set temperature. When the temperature is within the temperature deviation range, the combustion operation is continued, and when the tapping 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 tapping temperature equal to the set temperature. The skill line currently used is updated.

In step 206, the performance lines L ₁ and L ₂
It is determined that there is no overlap with
_When a change command from ₁ to L ₂ is issued, the water flow control valve 16 narrows down the water flow by a predetermined amount (α) at the position of the combustion performance at point Q ₁ of the performance line L ₁ to slightly reduce the combustion performance.
Performs as combustion control in capacity line L _1. Then, in step 210, it is determined whether or not the tapping temperature is within the temperature deviation range of the set temperature. If the tapping temperature is not within the temperature deviation range, the operations of steps 208 to 210 are repeated to bring the tapping temperature into the temperature deviation range. Control. When the tapping temperature falls within the temperature deviation range and the tapping temperature is substantially equal to the set temperature, the flow rate control valve 16 is stopped in step 212 after confirming the stable state of the flow rate.

Next, at step 213, it is determined from the detection signal of the flow rate sensor whether or not an increase in the amount of water has been requested due to, for example, further opening of the hot water tap 1 or an increase in the water pressure, as shown in FIG. In addition, when an increase in the amount of water is recognized, the state of the increase in the amount of water
₁ second, stable capacity line L ₁ make sure that that Q ₁
By Utsura jumps to point C of the capacity line L ₂ from point switches the capacity line from L ₁ to L _2. And step 216
In wait for lapse of t ₂ seconds by the timer 39 determines whether or not there is reduction of tapping temperature at step 217.

When a drop in the tapping temperature is recognized, it is determined that the request for increasing the combustion capacity is not appropriate, and in step 208, the amount of water is reduced to reduce the combustion capacity, and the capacity line L
Perform combustion operation back from ₂ to L _1. If it is determined in step 217 that the tap water temperature does not decrease and that the tap water temperature falls within the temperature deviation range of the set temperature, the water flow control valve 16 is driven to set the tap water temperature in order to respond to the request for increasing the flow rate. While confirming that the temperature is within the temperature deviation range, the total water amount increases until the appropriate water amount FW _SP is reached, and when the water flow reaches the appropriate water amount, or when the water amount control valve 16 is fully opened. When this happens, the combustion operation is continued by the operation from step 222 on.

According to this embodiment, the performance lines L ₁ and L ₂
And the overlap fee with both ability lines L ₁ ,
When Soraketsu portion occurs between L ₂ also, by the operation of the capacity line wrap determination unit 41 and the capacity line switching buffer operation unit 42, and that can be switched in without trouble capacity lines L ₁ and L ₂ Become.

Therefore, the water heater is used in an area where the gas supply pressure is out of the predicted range and becomes low, and the combustion capacity characteristic data is updated. As a result, the capacity line L
Even Soraketsu portion occurs even between ₁ and L _2, will be able to switch the capacity line L ₁ and L ₂ on demand heat, it is possible to provide a user-friendly water heater.

The present invention is not limited to the above-described embodiment, but can take various embodiments. For example, although an example of two-stage switching has been described as a burner of a capability switching type, the present invention is also applicable to a case of using a burner of a three-stage switching type. In the case of switching of three or more levels, a performance characteristic line corresponding to the number of levels is given. If there is no overlap between the respective performance characteristic lines, switching between the performance lines is performed by the same operation as in the above embodiment. Will be performed.

Further, in the above embodiment, the performance line L ₁
When the switching to L _2, with capacity line L ₁ once targeted flow rate, when detecting an increase in flow rate, based on the signal of the flow sensor 9 has been detected an increase in the flow rate, thereby a pressure sensor or a hot water thermistor 11 May be detected. When the increase in the flow rate is detected, the water amount control valve 16 is in a state in which the water amount control is stopped. In this state, it is confirmed that when the hot water tap 1 is further opened, the load water pressure decreases. By detecting, an increase in the flow rate can be detected. Further, as shown in FIG. 4, when the amount of water is increased, the tapping temperature drops, so that a drop in the tapping temperature can be detected to detect an increase in the flow rate.

Further, in each of the above embodiments, the description has been given of a water heater as a combustion device. However, the present invention is not limited to an air conditioner for heating or cooling using gas or oil as fuel, or another combustion device such as a bath kettle. Also applies to

[0053]

According to the present invention, when the switching of the combustion performance characteristic line is instructed during the combustion operation, the overlap margin between the used combustion performance characteristic line and the switching target combustion performance characteristic line is obtained. Judgment is made as to whether or not there is, and when an empty space with no overlap margin has occurred, the combustion capacity characteristic line is configured to be smoothly switched by the capacity line switching buffer operation unit. Even if the fuel supply pressure is out of the predicted range and is low, and the combustion capacity line is updated to match the actual operation situation and there is an empty space between the capacity lines without overlap, there is no problem. Therefore, it is possible to switch the combustion capacity line, and a suitable combustion operation can be performed.

[Brief description of the drawings]

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

FIG. 2 is a flowchart showing the operation of the embodiment.

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

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

FIG. 5 is an explanatory diagram of a combustion capacity characteristic line given 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 graph showing a governing characteristic of a gas proportional valve used in a water heater.

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

[Explanation of symbols]

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

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-25625 (JP, A) JP-A-2-225907 (JP, A) JP-A-7-198129 (JP, A) JP-A-7- 198131 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) F23N 1/02 101 F23N 1/08 101 F23N 5/14 370 F24H 1/10 301

Claims (1)

(57) [Claims] 1. A combustion heating means for heating a fluid to be heated passing through a heat exchanger, a flow control means for controlling a flow rate of the fluid to be heated, and a fuel supply control means for controlling an amount of fuel supplied to the combustion heating means. A plurality of combustion capacity characteristic lines are provided according to the combustion capacity range, and the jump between the lines is performed on the upper side of the adjacent combustion capacity characteristic line with the smaller capacity and the lower side of the combustion capacity characteristic line with the larger capacity. A combustion performance characteristic line corresponding to the required combustion performance is selected by jumping, and the combustion heating means is driven for combustion in accordance with the selected combustion performance characteristic line to increase the temperature of the fluid to be heated to the set temperature. A capacity line determining unit for determining switching of a combustion performance characteristic line during a combustion operation and designating a combustion performance characteristic line to be switched according to a required combustion performance; A capacity line lap determination unit that determines whether there is an overlap margin of the combustion capacity between the jumping portion of the adjacent one of the combustion capacity characteristic lines and the jumping arrival part of the other combustion capacity characteristic line. When the capacity line overlap determination unit determines that there is no overlap margin, and when the combustion capacity of the empty space without the overlap margin is required, the combustion capacity is reduced by reducing the flow rate of the fluid to be heated. in the state of being restrained to hopping of lowering the combustion capacity characteristic line to heat the heated fluid to a set temperature to perform the combustion control, in use when the flow rate increases in the heated fluid request is detected by the combustion state When a jump is made from the combustion performance characteristic line to a combustion performance characteristic line having a higher combustion performance, and a combustion performance characteristic smaller than the fly-out portion below the combustion performance characteristic line is required. Capacity switching combustion device having a capacity line switching cushioning movement unit to switch to a more capacity smaller combustion capability characteristic line Lower the combustion capability down the flow rate jump over the depleted portion non-overlapping margin of the heated fluid.