JP3745008B2 - Burner combustion equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a burner combustion method and a combustion apparatus in which fuel and primary air are mixed and burned.
[0002]
[Prior art]
In a burner combustion apparatus (for example, a gas water heater) that mixes and burns fuel and primary air, it is generally known that the primary air is supplied by a blower fan. The number of rotations of the blower fan is controlled so as to obtain an air supply amount corresponding to the burner combustion amount. In this case, the amount of air supplied corresponding to the amount of combustion of the burner, or the rotational speed of the blower fan corresponding to the amount of supplied air is determined so that good combustion of the burner can be obtained during steady combustion operation of the burner. Yes.
[0003]
In this type of combustion apparatus, conventionally, the burner is supplied to the burner at the rotation speed of the blower fan determined as described above on the assumption that the burner is in a steady combustion operation from the start of combustion of the burner. I was trying to supply air.
[0004]
However, in such a case, particularly when the temperature in the vicinity of the burner is low at the start of combustion, the combustion flame is temporarily lifted at the initial stage of combustion, and it is easy to cause defective combustion. It became clear by examination.
[0005]
As a result of various studies by the inventors of the present application regarding this point, the following knowledge was obtained.
[0006]
That is, when the temperature in the vicinity of the burner is low at the start of the combustion operation, the temperature of the primary air mixed with the burner fuel is lower than in the steady combustion operation of the burner, so the combustion flame combustion speed is also steady. Slower than during combustion operation. For this reason, when the combustion operation is started in a state where the temperature near the burner is low, if the burner is supplied with an air supply amount for steady combustion operation, the air supply amount becomes excessive at the initial stage of the combustion operation, and the burner The jet speed of the air-fuel mixture becomes considerably higher than the combustion speed, and the combustion flame lift tends to occur. If combustion of the burner continues after the start of the combustion operation, the temperature of the primary air rises due to the radiant heat, and the combustion speed also increases.
[0007]
[Problems to be solved by the invention]
In view of the such circumstances, and an object thereof is to provide a combustion apparatus Luba over Na can perform good combustion operation without causing lifting of the combustion flame at the start combustion.
[0008]
[Means for Solving the Problems]
In order to achieve this object, the burner combustion apparatus of the present invention is a burner combustion apparatus comprising a blower fan that supplies primary air mixed with fuel to the burner, and is supplied to the burner by the blower fan. A temperature detecting means for detecting a temperature in the vicinity of the burner, and a fan for steady combustion of the burner when the supply air temperature detected by the temperature detecting means at the start of the combustion operation of the burner is equal to or lower than a predetermined temperature Combustion start rotational speed setting means for setting a combustion start rotational speed smaller than the rotational speed in accordance with the detected supply air temperature, and the blower fan at the combustion start rotational speed set at the start of the combustion operation of the burner The rotation speed of the blower fan is gradually increased from the combustion start speed toward the fan speed for steady combustion after the burner starts combustion. Control means, and the combustion start rotation speed setting means sets the combustion start rotation speed to be larger as the detected supply air temperature is higher, and the fan control means is configured to start the combustion of the burner, The rotational speed of the blower fan is increased from the combustion start rotational speed toward the fan speed for steady combustion at a predetermined rate of time increase .
[0014]
According to the present invention, when the supply air temperature detected by the temperature detection means at the start of the combustion operation of the burner is in a low temperature state equal to or lower than the predetermined temperature , the combustion start rotation speed setting means causes the steady combustion of the burner. A combustion start rotational speed smaller than the fan rotational speed is set according to the detected supply air temperature. At this time, the combustion start rotational speed is set so as to increase as the detected supply air temperature increases. Then, the constant by the pre-Symbol fan control means rotates the blowing fan in a combustion start rotation speed which is the set, gradually in subsequent predetermined time rate of increase of the rotational speed predetermined for air blowing fan Increase toward the fan speed for combustion . For this reason, the burner is supplied with an air supply amount that matches the supply air temperature from the start of the combustion operation, and an appropriate injection speed corresponding to the combustion speed corresponding to the supply air temperature is achieved. Maintained at speed.
[0015]
As a result, according to the burner combustion apparatus of the present invention, even if the combustion speed is low at the start of combustion, the ejection speed is limited so as to cope with it. It can be carried out.
[0017]
In addition , the air supply amount corresponding to the combustion start rotational speed at the start of the combustion operation and the ejection speed corresponding to the air supply amount increasing in response to the subsequent increase in the fan rotational speed are surely matched to the combustion speed. Therefore, it is possible to reliably perform a good combustion operation at the start of combustion.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. 1 is a system configuration diagram of a gas water heater provided with a burner combustion apparatus of the present embodiment, FIG. 2 is a block diagram of the main part of the gas water heater of FIG. 1, and FIG. 3 is a diagram of a burner of the gas water heater of FIG. It is a diagram for demonstrating a combustion action.
[0019]
With reference to FIG. 1, the water heater of a present Example is provided with the water heater main body 1 and the remote control 2 connected to it.
[0020]
The water heater main body 1 includes a water supply channel 3, a gas burner 4, a combustion chamber 5 that houses the gas burner 4, a blower fan 6 that supplies combustion air into the combustion chamber 5, and a control that controls the operation of the water heater. A unit 7 and a fuel supply path 8 for supplying fuel gas to the gas burner 4 are provided.
[0021]
The water supply path 3 includes an original water supply pipe 9, a heat exchanger pipe 10, and a hot water pipe 11 that are sequentially connected in series from the upstream side to the downstream side, and a bypass pipe 12 that is connected in parallel to the heat exchanger pipe 10. It is comprised by. At the branch point from the original water supply pipe 9 to the heat exchanger pipe 10 and the bypass pipe 12, there is an electric water amount control valve 13 that adjusts the ratio of the amount of water flowing through the heat exchanger pipe 10 and the bypass pipe 12 according to the instruction of the control unit 7. Is provided.
[0022]
The main water supply pipe 9 has an upstream side connected to the water supply and a downstream side connected to the inlet of the electric water amount control device 13. The main water supply pipe 9 has a water filter / drain plug 14 from the upstream side, a water amount sensor 15 for detecting the flow of water in the water supply channel 3 and the flow rate of water flowing through the water supply channel 3, and a water supply temperature. A water supply thermistor 16 is arranged.
[0023]
The heat exchanger pipe 10 has an upstream inlet side connected to one outlet side of the electric water amount control device 13, an intermediate portion thereof passing through a heat exchanger 17 provided above the gas burner 4, and a downstream outlet side connected to the outlet pipe 11. Has been. The heat exchanger 17 is heated by the combustion of the gas burner 4, whereby the water flowing inside the heat exchanger tube 10 is heated in the process of passing through the heat exchanger 17. Further, an overheat prevention device 18 for preventing overheating of the heat exchanger 17 is disposed on the outer wall of the heat exchanger 17, and water that has passed through the heat exchanger 17 is disposed on the downstream outlet side of the heat exchanger pipe 10. A can thermistor 19 for detecting the temperature of the hot water is provided.
[0024]
The bypass pipe 12 is connected to the other outlet side of the electric water amount control device 13 at the upstream inlet side and is diverted from the main water supply pipe 9, and the downstream end is upstream of the tap water pipe 11 (downstream end side of the heat exchanger pipe 10). Merged and connected.
[0025]
The tapping pipe 11 detects the tapping temperature of the hot water flowing through the tapping pipe 11 of the water supply channel 3 on the downstream side of the joining point between the heat exchanger pipe 10 and the bypass pipe 12 in order to prevent freezing. A hot water discharge thermistor 21, an overpressure safety valve / water tap 22 and a hot water tap 23 for discharging hot water are disposed from the upstream side to the downstream side. The hot-water tap 23 is a hot-water tap that adjusts the amount of hot water discharged from a faucet (not shown) arranged in the kitchen or bathroom.
[0026]
In the fuel supply path 8, the original solenoid valve 24 that opens and closes under the control of the control unit 7 and the fuel gas supply amount according to the amount of current supplied by the control unit 7 are sequentially supplied from the upstream side. A variable governor proportional solenoid valve 25 is provided.
[0027]
In the combustion chamber 5 containing the gas burner 4, an exhaust passage 26 for collecting combustion exhaust gas and discharging it to the outside is extended in the upper part, and the combustion air of the gas burner 4 is supplied to the combustion chamber 5. An air supply passage 27 is communicated, and the air blowing fan 6 is provided in the air supply passage 27.
[0028]
In this case, the combustion air supplied to the gas burner 4 by the blower fan 6 through the air supply passage 27 is partially a primary air, and a fuel gas supplied to the gas burner 4 from the fuel supply path 8 and a damper (not shown). Etc., and the mixture is burned by the gas burner 4. The remainder of the combustion air supplied by the blower fan 6 is used as secondary air for the combustion flame of the gas burner 4. A distribution plate 4a is provided in the secondary air supply passage to improve the distribution of air to the burner 4 and to increase the primary air supply pressure. Further, in the combustion chamber 5, a temperature sensor 28 (temperature detecting means) for detecting the supply temperature of the primary air supplied from the supply passage 27 to the gas burner 4 is provided in the vicinity of the gas burner 4 (for example, primary air). And in the vicinity of the portion where the fuel gas is mixed.
[0029]
In FIG. 1, 29 is an ignition electrode that generates spark discharge for igniting the gas burner 4, 30 is an igniter that drives the ignition electrode 29 under the control of the control unit 7, and 31 is a frame for detecting the combustion flame of the gas burner 4. A rod 32 is a thermal fuse for preventing overheating in the combustion chamber 5, and 33 is a low temperature detection switch for operating the freeze prevention heater 20. In addition, the remote controller 2 is provided with a temperature setting switch 34, an operation switch 35, and the like for setting the tapping temperature.
[0030]
Next, referring to FIG. 2, the control unit 7 is constituted by a microcomputer or the like, and its main functional configuration is a fuel supply control for controlling the fuel gas supply to the gas burner 4. Unit 36, fan control unit 37 (fan control means) for controlling the blower fan 6, combustion amount setting unit 38 for setting the combustion amount of the gas burner 4, and detection by the temperature sensor 28 at the start of the combustion operation of the gas burner 4. A combustion start rotation speed setting unit 39 (combustion start rotation speed setting means) for setting the rotation speed (combustion start rotation speed) of the blower fan 6 at the start of combustion according to the supplied air temperature, as will be described later. .
[0031]
In this case, the combustion amount setting unit 38 sets the combustion amount of the gas burner 4 so that the tapping temperature detected by the tapping temperature thermistor 21 during the hot water supply operation matches the set temperature set by the temperature setting switch 34 of the remote controller 2. Then, it is given to the fuel supply control unit 36 and the fan control unit 37. However, the combustion amount setting unit 38 sets a predetermined predetermined combustion amount at the start of combustion of the gas burner 4.
[0032]
Then, the fuel supply control unit 36 determines an energization amount to the governor proportional solenoid valve 25 so as to supply the fuel supply amount corresponding to the set combustion amount to the gas burner 4, and the proportional energization amount is determined by the determined energization amount. The solenoid valve 25 is energized and the original solenoid valve 24 is opened and closed when the hot water supply operation is started and stopped.
[0033]
Further, the fan control unit 37 basically determines the rotational speed of the blower fan 6 so as to supply the gas burner 4 with an air supply amount corresponding to the combustion amount set by the combustion amount setting unit 38, and the determination. The blower fan 6 is actuated at the rotation speed. However, the fan control unit 37 is described later when the supply air temperature detected by the temperature sensor 28 at the start of the combustion operation of the burner 2 is in a low temperature state that is equal to or lower than a predetermined temperature (a temperature at which lift may occur). Thus, the rotational speed of the blower fan 6 is controlled based on the combustion start rotational speed of the blower fan 6 set by the combustion start rotational speed setting unit 39.
[0034]
Note that the fuel supply amount and the rotational speed of the blower fan 6 defined by the fuel supply control unit 36 and the fan control unit 37 corresponding to the combustion amount set by the combustion amount setting unit 38 as described above are the combustion chamber. The temperature inside the gas burner 2 is sufficiently high and the supply temperature to the gas burner 4 is also sufficiently high. The gas burner 2 is determined so that the combustion can be performed satisfactorily during the steady combustion operation. .
[0035]
Although not shown in detail in FIG. 2, in addition to the detection signal of the temperature sensor 28, the control unit 7 detects each sensor such as the tapping temperature thermistor 21, the feed water temperature thermistor 16, and the water amount sensor 15. The signal is input as data for setting the combustion amount by the combustion amount setting unit 38.
[0036]
Next, the operation of the water heater of the present embodiment during hot water supply (when the gas burner 4 is combusted) will be described. First, the basic operation of the water heater will be described.
[0037]
When water flow through the water supply channel 3 is started, this is detected by the control unit 7 via the water amount sensor 15, and at this time, the control unit 7 uses the combustion amount setting unit 38 to perform predetermined combustion at the start of combustion of the gas burner 4. As will be described later while setting the amount, the blower fan 6, the original solenoid valve 24, the governor proportional solenoid valve 25, etc. are controlled to start the combustion operation of the gas burner 4. Then, when the combustion operation of the gas burner 4 is started, the control unit 7 starts the tapping temperature detected by the tapping temperature thermistor 21 (water tapping water that combines water flowing through the heat exchanger pipe 10 and water flowing through the bypass pipe 12). (Temperature) is controlled by the blower fan 6 and the governor proportional solenoid valve 25 while setting the combustion amount of the gas burner 4 by the combustion amount setting unit 38 so as to match the set temperature set by the temperature setting switch 34 of the remote controller 2, The amount of blown air and the amount of fuel supplied to the gas burner 4 are controlled.
[0038]
As a result, water flowing toward the hot water tap 23 through the water supply channel 3 is heated with a required amount of heat through the heat exchanger 17 by the heat of combustion of the gas burner 4 in the heat exchanger pipe 10. And the water heated with the heat exchanger pipe | tube 10 joins the non-heated water which flows through the bypass pipe 12, turns into hot water which corresponds to preset temperature, and the hot water supply to the hot-water tap 23 is performed at preset temperature.
[0039]
When the water flow through the water supply channel 3 is stopped, this is detected by the control unit 7 via the water amount sensor 15, and at this time, the control unit 7 stops the combustion operation of the gas burner 4.
[0040]
In such a hot water supply operation, the combustion operation of the gas burner 4 is performed as follows.
[0041]
First, when the combustion of the gas burner 4 is started, the supply temperature of the gas burner 4 is detected by the temperature sensor 28, and the combustion start rotation of the blower fan 6 is detected by the combustion start rotation speed setting unit 39 of the control unit 7 in accordance with the detected temperature. Number is set. As shown in FIG. 3B, the combustion start rotational speed is higher than the rotational speed for steady combustion of the gas burner 4 (the rotational speed corresponding to a predetermined combustion amount set at the start of combustion by the combustion amount setting unit 38). It is set to be smaller and larger as the detected temperature of the supply air temperature is higher (smaller as the detected temperature is lower). When the temperature in the combustion chamber 5 is sufficiently high and the temperature detected by the temperature sensor 28 is equal to or higher than a predetermined temperature, such as when the combustion is resumed immediately after the combustion of the gas burner 4 is stopped, it is used for steady combustion. The rotation speed is set as the combustion start rotation speed.
[0042]
When the combustion start rotational speed is set in this way, the control unit 7 causes the fan control section 37 to rotate the blower fan 6 at the set combustion start rotational speed, and the fuel supply control section 36 is operated by the original solenoid valve. After the valve 24 is opened, the energization amount of the governor proportional solenoid valve 25 is set so that the fuel gas is supplied from the fuel supply path 8 to the gas burner 4 with the fuel supply amount corresponding to the combustion amount set by the combustion amount setting unit 38. Control. In this state, the control unit 7 causes the ignition electrode 29 to generate a spark discharge for a certain period of time via the igniter 30 and ignites the air-fuel mixture ejected from the flame outlet of the gas burner 4 to start combustion.
[0043]
After the start of combustion, the fuel supply control unit 36 controls the governor proportional electromagnetic so as to continue the fuel supply to the gas burner 4 with the fuel supply amount corresponding to the combustion amount set by the combustion amount setting unit 38 according to the tapping temperature etc. While the energization control of the valve 25 is continued, the fan control unit 37 changes the rotational speed of the blower fan 6 toward the rotational speed for steady combustion, for example, at a predetermined time increase rate, as shown in FIG. increase. Then, after the rotational speed of the blower fan 6 finally increases to the rotational speed for steady combustion, the fan control unit 36 performs the blower fan 6 at a rotational speed corresponding to the combustion amount set by the combustion amount setting unit 38. Is activated.
[0044]
When the temperature detected by the temperature sensor 28 at the start of combustion is not more than a predetermined temperature and the supply air temperature of the primary air to the gas burner 4 by the blower fan 6 is low due to such combustion operation of the gas burner 4, combustion is performed. Since the rotation speed of the blower fan 6 at the start is controlled to be a combustion start rotation speed that is smaller than the rotation speed for steady combustion, in other words, with a small amount of air supply consistent with a low air supply temperature, in other words, a low combustion speed The primary air to be mixed with the fuel gas is supplied to the gas burner 4 with a small amount of air supply consistent with the above. Therefore, the jet speed of the air-fuel mixture ejected from the flame outlet of the gas burner 4 matches the combustion speed of the air-fuel mixture as in the case of steady combustion of the gas burner 4, and the gas burner does not cause the combustion flame lift. 4 combustion can be started.
[0045]
After the start of combustion of the gas burner 4, the supply air temperature detected by the temperature sensor 28 increases as shown in FIG. 3 (a) due to the combustion heat of the gas burner 4, and accordingly the combustion speed also increases. However, as the combustion speed increases, the rotational speed of the blower fan 6 is increased toward the rotational speed for steady combustion, and the amount of air supplied to the gas burner 4 is also increased. As shown in FIG. 3C, after the combustion of the gas burner 4 is started, the jet speed of the air-fuel mixture is also increased so as to match the gradually increasing combustion speed.
[0046]
As a result, even when the supply air temperature is low and the combustion speed of the gas mixture in the gas burner 4 is low at the beginning of the combustion operation of the gas burner 2, the gas mixture burns at a consistent jet speed. A good combustion operation that does not occur can be performed.
[0047]
Further, when the supply air temperature detected by the temperature sensor 28 at the start of the combustion operation is in a low temperature state below a predetermined temperature, the higher the supply air temperature, the higher the combustion start rotational speed of the blower fan 3 (supply). In other words, the higher the combustion speed, the higher the combustion start rotational speed of the blower fan 3 is set. Therefore, it is ensured that the combustion operation is started from the start of the combustion operation. The primary air mixed with the fuel gas is supplied to the burner body 5 with an air supply amount that matches the air temperature, and the injection speed of the air-fuel mixture surely matches the combustion speed, so that a good combustion operation is performed reliably. be able to.
[0048]
Further, when the supply air temperature detected by the temperature sensor 28 is equal to or higher than a predetermined temperature, such as when the combustion operation is restarted immediately after the combustion of the gas burner 4 is stopped, the rotational speed for steady combustion is from the start of combustion. Since the blower fan 6 operates, in order to ensure a good combustion operation, in the state where the air supply to the gas burner 4 by the blower fan 6 should be performed at the rotational speed for steady combustion from the start of the combustion operation, Thus, it is possible to avoid a situation in which the combustion operation of the gas burner 4 is started in a state where the blower fan 6 operates at a lower rotational speed and the supply amount of the gas burner 4 is too small.
[0049]
Therefore, in the water heater of the present embodiment, it is possible to reliably perform a good combustion operation without causing a combustion flame lift or the like from the start of combustion of the gas burner 4.
[0050]
In the embodiment described above, the gas burner 4 provided in the water heater has been described as an example. However, the present invention is not limited to this, and the present invention may be applied to other combustion apparatuses. In the present embodiment, the Bunsen burner has been described. However, the present invention can also be applied to a semi-Bunsen burner or an all-primary air burner.
[0051]
Further, in the present embodiment, the air supply amount is increased at a predetermined increase rate after the start of the burner combustion operation. However, the air supply amount is increased according to the detected temperature of the primary air. May be.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a gas water heater provided with a burner combustion apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram of a main part of the gas water heater in FIG.
3 is a diagram for explaining the combustion operation of the burner of the gas water heater in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 4 ... Gas burner, 6 ... Blower fan, 28 ... Temperature sensor (temperature detection means), 37 ... Fan control part (fan control means), 39 ... Combustion start rotation speed setting part (combustion start rotation speed setting means)

Claims (1)

In a burner combustion apparatus comprising a blower fan for supplying primary air mixed with fuel to a burner, temperature detection means for detecting a supply air temperature to the burner by the blower fan at a location near the burner, and When the supply air temperature detected by the temperature detection means at the start of the combustion operation of the burner is equal to or lower than a predetermined temperature, a combustion start rotation speed smaller than the fan rotation speed for steady combustion of the burner is detected. Combustion start rotational speed setting means that is set according to temperature, and the blower fan is rotated at the set combustion start rotational speed at the start of the combustion operation of the burner, and the rotational speed of the blower fan is started after the combustion of the burner is started. Fan control means for gradually increasing the combustion start rotational speed from the combustion start rotational speed toward the fan speed for steady combustion, the combustion start rotational speed setting means, The higher the supplied air temperature, the larger the combustion start rotational speed, and the fan control means determines the rotational speed of the blower fan from the combustion start rotational speed after the combustion of the burner is started. Further , the burner combustion apparatus is configured to increase toward the fan speed for steady combustion at a predetermined time increase rate .

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