JP3578547B2 - Combustion equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a burner for heating a heat exchanger for heating a heating medium,
Fuel supply amount adjusting means for adjusting the fuel supply amount to the burner;
Air supply amount adjustment means for adjusting the combustion air supply amount to the burner,
Air supply amount setting means for setting the combustion air supply amount according to the fuel supply amount so that the excess air ratio increases as the fuel supply amount increases,
The present invention relates to a combustion apparatus provided with control means for controlling the operation of the air supply amount adjusting means so that the combustion air supply amount set by the air supply amount setting means is obtained.
[0002]
[Prior art]
Conventionally, the air supply amount setting means is configured to set the combustion air supply amount as described below.
That is, as shown in FIG. 5, the excess air ratio α increases as the fuel supply amount F increases in accordance with the fuel supply amount F so as to maintain the thermal efficiency R constant regardless of the fuel supply amount F. The combustion air supply amount is set in accordance with the fuel supply amount F so that the excess air ratio α is set as described above.
[0003]
The thermal efficiency is indicated by the ratio of the amount of heat transferred to the heat medium in the heat exchanger, of the amount of heat generated by burning the fuel supplied to the burner. That is, the fuel supply amount is F, the heat generation amount generated when a unit amount of fuel is burned is C, the inflow temperature of the heat medium into the heat exchanger is Ti, and the outflow temperature of the heat medium from the heat exchanger is To. , And the heat capacity of the heat medium is represented by D, and the thermal efficiency R is obtained from the following equation.
R = {(To-Ti) × Qi × D} (F × C) (1)
[0004]
In other words, increasing the thermal efficiency means reducing the excess air ratio. Therefore, the higher the thermal efficiency, the higher the temperature of the combustion gas of the burner, and the higher the temperature of the heat medium flowing out of the heat exchanger, which is advantageous in terms of energy saving. (Hereinafter referred to as NOx) and the amount of condensed water (hereinafter referred to as drain) that corrodes the heat exchanger increases, which is a problem.
[0005]
Therefore, conventionally, as shown in FIG. 5, when the fuel supply amount F is the maximum within the adjustment range (hereinafter, sometimes referred to as the maximum fuel supply amount F _max ), the drain and the NOx generation amount pose a problem. become not allowable value to be less than, set the thermal efficiency R (e.g., about 80% or less, thus setting the thermal efficiency R may be referred to as maximum input Tokinetsu efficiency value R _a), the fuel supply amount F Regardless, the supply amount of combustion air is adjusted so that the thermal efficiency R is maintained at the maximum input thermal efficiency value _Ra , so that the amount of drainage and NOx generation does not matter.
[0006]
[Problems to be solved by the invention]
However, the conventional combustion apparatus has no problem in terms of the amount of drainage and NOx generated, but still has room for improvement in terms of energy saving.
[0007]
The present invention has been made in view of the above circumstances, and an object of the present invention is to improve energy saving while not causing a problem in drain and NOx generation.
[0008]
[Means for Solving the Problems]
If the thermal efficiencies are the same, the smaller the fuel supply amount, the smaller the drain and NOx generation amount. Therefore, when the fuel supply amount is smaller than the maximum value, the thermal efficiency can be set to a value larger than the maximum input thermal efficiency value while the drain and NOx generation amounts are kept below the allowable values.
[0009]
The present invention is based on the above-mentioned viewpoint, and in the characteristic configuration according to claim 1, the thermal efficiency and the fuel supply amount are within the adjustment range in a state where the amount of drain and NOx generated is suppressed to an allowable value or less. Is set to be greater than the maximum value of the fuel supply amount within the adjustment range, that is, the maximum input thermal efficiency value, and the fuel supply amount is set to the maximum value within the adjustment range. When it is between the minimum and the minimum, the combustion air supply amount is set so that the fuel supply amount is not less than the maximum input thermal efficiency value and not more than the minimum value within the adjustment range. Then, the control means obtains an actual value of the thermal efficiency, and controls the operation of the air supply amount adjusting means so that the obtained actual thermal efficiency becomes the thermal efficiency set according to the fuel supply amount. It is.
In addition, based on the above-mentioned viewpoint, when the fuel supply amount is the minimum within the adjustment range, the thermal efficiency can be set to the maximum, so that the heat efficiency can be reduced when the fuel supply amount is the minimum within the adjustment range. When the value is set to the maximum and the fuel supply is between the maximum and the minimum within the adjustment range, setting the fuel supply to a value equal to or less than the minimum value within the adjustment range is effective in terms of energy saving. It becomes.
Accordingly, it has become possible to improve energy saving while preventing the generation of drain and NOx from becoming a problem.
[0010]
By the way, the thermal efficiency can be increased as the fuel supply amount decreases, but as the thermal efficiency increases, the excess air ratio decreases, and if the excess air ratio becomes too small, the stable burnability of the burner is impaired. I do. Therefore, even if the thermal efficiency is increased, it is necessary to ensure stable burnability of the burner.
[0011]
Therefore, in the characteristic configuration according to the second aspect, as shown in FIG. 2, when the fuel supply amount F is the minimum within the adjustment range (hereinafter, sometimes referred to as the minimum fuel supply amount F _min ), the burner The minimum value α _min of the excess air ratio α capable of performing stable combustion of the above is determined, and the thermal efficiency R corresponding to the minimum excess air ratio α _min is set as the maximum thermal efficiency value R _max . Further, within the adjustment range of the fuel supply amount F, when the thermal efficiency R is set to the maximum thermal efficiency value _Rmax , the maximum value of the fuel supply amount F that can suppress the amount of drain and NOx generation to an allowable value or less is determined. _Is set as the set value FS.
Then, the thermal efficiency R, when fuel supply amount F is equal to or greater than the set value F _S, while suppressing the allowable value or less drainage and NOx generation amount, the more the fuel supply amount F becomes large small west, and the fuel when the supply amount F is the maximum fuel supply amount F _max, and the maximum input Tokinetsu efficiency value R _a, and, when the smaller than the fuel supply amount F is the set value F _S, the maximum thermal efficiency value R _max Set to maintain. Then, the excess air ratio α is set according to the fuel supply amount F so as to achieve the thermal efficiency R set as described above, and the combustion air supply amount is set so as to achieve the excess air ratio α thus set. It is.
[0012]
Incidentally, when the thermal efficiency R is set in a state in which the stable burnability of the burner is ensured, for example, as shown in FIG. 3, the thermal efficiency R is set to the value when the fuel supply amount F is the minimum fuel supply amount _Fmin. set to the maximum thermal efficiency value R _max, the maximum input Tokinetsu set efficiency value R _a, maximum fuel supply amount F is a minimum fuel supply amount F _min value of the time of fuel supply amount F is the maximum fuel supply amount F _max When the fuel supply amount _Fmax is between the fuel supply amount _Fmax and the fuel supply amount F, the thermal efficiency R is set to be smaller as the fuel supply amount F increases, or as shown in FIG. as when the set value Fs small to maintain the maximum heat efficiency values R _max, and, when the fuel supply amount F is equal to or greater than the set value Fs, set to maintain the maximum input Tokinetsu efficiency value R _a Is assumed.
[0013]
However, when the thermal efficiency is set as shown in FIG. 2 as compared with the case where the thermal efficiency is set as shown in FIG. 3 and FIG. 4, stable burnability of the burner is ensured. In this state, the thermal efficiency can be set as large as possible.
Therefore, according to the characteristic configuration of the second aspect, energy saving can be improved as much as possible without causing any problem in the amount of drainage and NOx generation.
[0014]
According to the characteristic configuration of the third aspect, the heat medium heated by the heat exchanger is supplied to the heating device as a heat source.
Since the heating device is operated for a long time, applying the present invention to a combustion device for supplying a heating medium to the heating device is preferable in terms of energy saving.
[0015]
According to the characteristic configuration of the fourth aspect, the heat medium heated by the heat exchanger is supplied to the floor heating device as a heat source.
The operation mode of the floor heating device is, among the heating devices, particularly one that is operated for a long time and in a low input state where the fuel supply amount is small.
Accordingly, when the present invention is applied to a combustion device for supplying a heating medium to a floor heating device, particularly among heating devices, it is optimal in terms of energy saving.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a heat source unit for a floor heating device will be described with reference to the drawings.
As shown in FIG. 1, a heat source device H for a floor heating device as an example of a combustion device according to the present invention includes a hot water generator 1, a control unit 2 that controls the operation of the hot water generator 1, and a control unit thereof. And an operation unit 3 for instructing the control unit 2 to perform a control operation. The heating medium generated by the hot water generator 1 is circulated and supplied to a floor heating device M as a heating device to heat the room. I have.
[0017]
The hot water generator 1 includes a combustion chamber 11, a gas burner 12 provided inside the combustion chamber 11, a heat exchanger 13 heated by the gas burner 12 to heat water as a heat medium, and a gas burner 12. A fan 14 for supplying combustion air, a heating return channel 15 for supplying a heat medium for heating to the heat exchanger 13, a heating outgoing channel 16 for delivering the heat medium heated in the heat exchanger 13, and a gas burner 12. And a fuel supply path 17 for supplying a fuel gas to the fuel cell.
[0018]
The heating return water passage 15 includes a water supply amount sensor 18 for detecting a flow rate Qi of the heat medium flowing through the heat exchanger 13 and an incoming water temperature sensor 19 for detecting an inflow temperature Ti of the heat medium into the heat exchanger 13. The heating outgoing water channel 16 is provided with a hot water temperature sensor 20 for detecting the outflow temperature To of the heat medium from the heat exchanger 13.
The fuel supply passage 17 is connected to a general household gas supply pipe. The fuel supply passage 17 has an electromagnetic gas amount adjusting valve 21 for adjusting a fuel supply amount F to the gas burner 12, and a fuel supply passage 17 to the gas burner 12. An electromagnetic on-off valve 22 for interrupting the supply of fuel gas is provided.
An igniter 23 for igniting the gas burner 12 and a frame rod 24 for detecting ignition are provided near the gas burner 12.
Further, a pump 25 for sending out hot water from the heating outgoing water passage 16 is interposed in the heating return water passage 15.
[0019]
That is, the gas amount adjusting valve 21 corresponds to a fuel supply amount adjusting unit, and the fan 14 corresponds to an air supply amount adjusting unit.
[0020]
The operation unit 3 includes an operation switch 26 for instructing operation and stop of the heat source device H, a temperature setting switch 27 for setting the target hot water supply temperature Ts, a display unit 28 for displaying the set target hot water supply temperature Ts, and lighting of the heat source device H. Is provided with an operation display lamp 29 and the like for displaying a state in which the vehicle is operating.
[0021]
The control unit 2 includes a microcomputer, and detects and stores information on the operation unit 3, the water supply amount sensor 18, the incoming water temperature sensor 19, the outgoing water temperature sensor 20, and the frame rod 24, as well as preset and stored. The operation of each of the fan 14, the gas amount adjustment valve 21, the on-off valve 22, the igniter 23, and the pump 25 is controlled based on various control information and a control program.
[0022]
The floor heating apparatus M is configured such that a hot water flow path 5 through which a heat medium flows is embedded in a mat-like body 4 laid on the floor in a state of being wrapped in a meandering shape over substantially the entire surface of the mat-like body 4. .
The inlet of the hot water flow path 5 is connected to the heating outgoing water path 16 of the hot water generator 1, and the outlet of the hot water flow path 5 is connected to the heating return water path 15 of the hot water generator 1.
Then, in the hot water generator 1, the heat medium heated to the target hot water supply temperature Ts set by the temperature setting switch 26 is supplied to the hot water flow path 5 through the heating going water path 16, and the hot water flow path 5 is caused to flow. After that, the return heat medium is supplied again to the hot water generator 1 through the heating return water passage 15.
[0023]
Next, the control operation of the control unit 2 will be described.
When the operation is commanded by the operation switch 26, the pump 25 is operated. When the flow rate Qi detected by the water supply amount sensor 18 becomes equal to or more than the set water amount, the ignition control of the gas burner 12 and the fuel supply amount F to the gas burner 12 are adjusted so that the outflow temperature To becomes the target hot water supply temperature Ts. At the same time, hot water supply control for controlling the fan 14 is executed as described later . When a stop command is issued by the operation switch 26, the pump 25 is stopped, and fire extinguishing control for stopping combustion of the gas burner 2 is executed.
[0024]
In the ignition control, the on-off valve 22 and the gas amount adjusting valve 21 are opened to supply fuel gas to the gas burner 2 and to perform ignition by the igniter 18. When ignition is confirmed by the flame rod 24, the ignition control is stopped, and subsequently, hot water supply control is executed.
[0025]
Hereinafter, the hot water supply control will be described.
As shown in FIG. 2, the thermal efficiency R and the excess air ratio α are set in advance according to the fuel supply amount F.
In addition, in FIG. 2, α _min is the minimum value of the excess air ratio α at which the stable combustion of the gas burner 12 is possible when the fuel supply amount F is the minimum fuel supply amount F _min , and the maximum thermal efficiency value R _max is the thermal efficiency R corresponding to its minimum excess air ratio α _min . F _S, within the adjustment range of the fuel supply amount F, when the heat efficiency R was the maximum heat efficiency values R _max, the maximum value of the fuel supply amount F can be suppressed to below the allowable value drain and NOx generation amount Which is equivalent to the set value.
Then, the thermal efficiency R, when fuel supply amount F is equal to or greater than the set value F _S, while suppressing the allowable value or less drainage and NOx generation amount, the small as the fuel supply amount F becomes large, and the fuel When the supply amount F is smaller than the set value F _S , it is set so as to maintain the maximum thermal efficiency value R _max . _Ra is the value of the thermal efficiency R when the fuel supply amount F is the maximum fuel supply amount _Fmax , and corresponds to the maximum input thermal efficiency value.
Further, the excess air ratio α is set in accordance with the fuel supply amount F so as to achieve the thermal efficiency R set as described above.
[0027]
Incidentally, for example, maximum fuel supply amount _{F max} is the case of the heat source apparatus H of the ability of the 12000 kcal / time value converted into heat, the set value _{F S} 8000 kcal / h, the maximum input Tokinetsu efficiency value _{R a} is The maximum thermal efficiency value R _max is set to 80% and the maximum thermal efficiency value R _max is set to 85%. In that case, the excess air ratio α when the maximum fuel supply amount F _max fuel supply amount F is 1.8, the fuel supply amount F is 1.6 excess air ratio α when the set value F _S .
[0028]
The control unit 2 obtains the actual value of the thermal efficiency, and controls the operation of the fan 14 so that the obtained actual thermal efficiency becomes the thermal efficiency set as shown in FIG. 2 according to the fuel supply amount. It is configured to
That is, the control unit 2 is based on the target hot water supply temperature Ts set by the temperature setting switch 27, the flow rate Qi detected by the water supply amount sensor 18, and the inflow temperature Ti detected by the incoming water temperature sensor 19. Then, the fuel supply amount F is obtained, and the gas amount adjusting valve 21 is controlled so as to become the obtained fuel supply amount F. Also, based on the obtained fuel supply amount F, the flow rate Qi detected by the water supply amount sensor 18, the inflow temperature Ti detected by the incoming water temperature sensor 19, and the outflow temperature To detected by the outflow water temperature sensor 20. Then, the thermal efficiency R is obtained by the above equation (1), and the fan 14 is controlled such that the obtained thermal efficiency R becomes a value corresponding to the fuel supply amount F as shown in FIG.
[0029]
In the fire extinguishing control, the on-off valve 22 and the gas amount adjusting valve 21 are closed, the fuel gas supply to the gas burner 2 is cut off, and the gas burner 2 is extinguished.
[0030]
Therefore, using the control unit 2, the air supply amount setting means for setting the combustion air supply amount according to the fuel supply amount F such that the larger the fuel supply amount F is, the larger the excess air ratio α is. 2A and a control means 2B for controlling the operation of the fan 14 so as to achieve the combustion air supply amount set by the air supply amount setting means 2A.
[0031]
[Another embodiment]
Next, another embodiment will be described.
(1) Set value F _S , maximum input thermal efficiency value R _a , maximum thermal efficiency value R _max , excess air ratio α when fuel supply amount F is maximum fuel supply amount F _max , and fuel supply amount F is set value F _S In this case, the excess air ratios α can be appropriately set according to the specifications of the heat source device H.
[0032]
(2) The relationship between the fuel supply amount F and the thermal efficiency R is not limited to the relationship shown in FIG.
For example, as shown in FIG. 3, the thermal efficiency R is set to a value when the fuel supply amount F is the minimum fuel supply amount F _min to the maximum thermal efficiency value R _max , and the fuel supply amount F is set to the maximum fuel supply amount F _max . the value set to the maximum input Tokinetsu efficiency value R _a of time, when the fuel supply amount F is between the minimum fuel supply amount F _min and a maximum fuel supply amount F _max is accompanied fuel supply amount F becomes larger May be set to be small.
As shown in FIG. 4, when the fuel supply amount F is smaller than the set value Fs, the maximum thermal efficiency value _Rmax is maintained, and when the fuel supply amount F is equal to or larger than the set value Fs, the maximum input efficiency is maintained. it may be set to maintain in time the thermal efficiency value R _a.
[0035]
(3) In the above-described embodiment of the present invention, the case where the gas burner 12 that burns gas fuel is applied as the burner is exemplified. However, as the burner, a liquid that burns a liquid fuel such as heavy oil or petroleum is used. A fuel burner can be applied.
[0036]
(4) In the above embodiment of the present invention, water is used as the heat medium. However, the heat medium is not limited to water, and any other heat-exchangeable and fluid substance can be used. Can be applied.
[0037]
(5) In the above embodiment of the present invention, the case where the present invention is applied to a heat source unit for a floor heating device is exemplified. However, in addition to the above, the present invention also applies to a heat source unit for various heating devices and a hot water supply device. It can be applied to devices and the like.
[0038]
Incidentally, reference numerals are written in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.
[Brief description of the drawings]
FIG. 1 is a block diagram of a heat source unit for a floor heating device. FIG. 2 is a diagram showing a relationship between a fuel supply amount, a thermal efficiency, and an excess air ratio. FIG. 3 is a fuel supply amount, a thermal efficiency, and an excess air amount in another embodiment. FIG. 4 is a diagram showing the relationship between the fuel supply amount and the thermal efficiency and the excess air ratio in another embodiment. FIG. 5 is a diagram showing the relationship between the fuel supply amount and the thermal efficiency and the excess air ratio in a conventional combustion device. Diagram showing the relationship with each other [Explanation of reference numerals]
Reference Signs List 12 burner 13 heat exchanger 14 air supply amount adjusting means 21 fuel supply amount adjusting means 2A air supply amount setting means 2B control means M heating device

Claims (4)

A burner (12) for heating a heat exchanger (13) for heating a heating medium;
Fuel supply amount adjusting means (21) for adjusting the fuel supply amount to the burner (12);
Air supply amount adjusting means (14) for adjusting the supply amount of combustion air to the burner (12);
Air supply amount setting means (2A) for setting the combustion air supply amount according to the fuel supply amount such that the larger the fuel supply amount is, the larger the excess air ratio is;
A combustion apparatus provided with control means (2B) for controlling the operation of the air supply amount adjusting means (14) so that the combustion air supply amount set by the air supply amount setting means (2A) is obtained. So,
The air supply amount setting means (2A) determines a ratio of a heat transfer amount given to a heat medium in the heat exchanger (13) to a heat amount generated by burning of fuel supplied to the burner (12). Is set so that the value when the fuel supply amount is the minimum within the adjustment range is larger than the value when the fuel supply amount is the maximum within the adjustment range, and the fuel supply amount is adjusted. When the fuel supply is between the maximum and the minimum in the range, the fuel supply amount is equal to or more than the maximum value in the adjustment range and the fuel supply amount is set to be equal to or less than the minimum value in the adjustment range. configured to set a use amount of air supply,
The control means (2B) obtains an actual value of the thermal efficiency, and the air supply amount adjusting means (14) so that the obtained actual thermal efficiency becomes a thermal efficiency set according to the fuel supply amount. A combustion device configured to control the operation of the combustion device. The air supply amount setting means (2A) decreases the thermal efficiency as the fuel supply amount increases, when the fuel supply amount is equal to or more than a set value corresponding to an intermediate portion within the adjustment range, and When the fuel supply amount is smaller than the set value, the combustion air supply amount is set so that the thermal efficiency is maintained at the value when the fuel supply amount is at the set value. 2. The combustion device according to 1. 3. The combustion device according to claim 1, wherein the heat medium heated by the heat exchanger is supplied to a heating device as a heat source. 4. The combustion device according to claim 3, wherein the heating device (M) is a floor heating device.

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