JP2000111037A - Ignition controller for petroleum water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress occurrence of a combustion sound at the time of igniting a petroleum water heater using a pressure spraying burner, an incomplete combustion gas or smoke. SOLUTION: A fuel pressurized by an electromagnetic pump 1 is discharged in a foggy state from a spraying nozzle, a blower 2 for supplying an air amount corresponding to the sprayed fuel is provided, and a burner for igniting sprayed fuel by a discharging spark of a discharging igniter 3 is mounted at a boiler of the water heater. The blower 2 is energized by the ignition to supply a large supply air amount to the burner, then deenergized to inertially supply the air. An ignition time phase control means 5 for slightly enhancing a fuel spraying pressure is mounted at the pump 1, an optimum air and fuel balance is obtained and ignited at the time of igniting in the state that the sprayed fuel flow rate is smaller than a specified fuel flow rate on the way of the inertial air supply, and then the blower 2 is again energized to realize soft ignition by a controller for increasing a fuel flow rate while enhancing the supply air volume to a specified air volume.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition control device that suppresses the generation of combustion noise, incomplete combustion gas, and smoke when igniting an oil hot water heater.

[0002]

2. Description of the Related Art A pressure spray burner used as a heat source of an oil hot water heater sends a predetermined amount of air blown by a blower, a specified fuel flow rate pressurized by an electromagnetic pump and blown out from a spray nozzle to the burner, and discharges the gas. Since ignition and combustion occur instantaneously with sparks generated from the electrodes, at the time of ignition, sound and vibration close to explosion sound are generated, and odors and smoke associated with incomplete combustion are generated.

For this reason, the electromagnetic pump controls the air flow rate and the fuel flow rate so that the burner at the time of ignition can be completely burned, with the main purpose of gradually increasing the discharge pressure (flow rate) by phase control, and causes ignition. Low fuel flow, then 1
There is a proposal of a soft ignition device for increasing the output to 00%.
(See No. 59-13480)

On the other hand, pressure spray burners used in oil hot water heaters do not allow a large amount of combustion to be regulated, so they operate intermittently when supplying a small amount of hot water, and are restarted during the after-purge time when the blower continues to rotate even after the fire is extinguished. Sometimes it takes. At the time of such reignition, there is a proposal to apply an emergency stop operation by applying a brake to the rotating blower, and then perform a normal ignition sequence. (Tokuhei 7-10930
(See No. 1)

[0005]

In an oil water heater using a pressure spray burner, reducing noise and vibration at the time of ignition involves igniting at a small fuel flow rate, and thereafter gradually increasing the amount of combustion. In order to reduce odor and smoke at the time of ignition, it is necessary to control and supply the amount of air so that the increased fuel flow can be completely burned. For this purpose, it is necessary to provide a phase control device in the blower as well as the electromagnetic pump to control the air amount finely, but as a practical matter, it will increase the cost greatly to perform the phase control up to the blower. is there.

[0006] For this reason, when power is supplied to the blower in the stopped state, there is always a delay time for the rotation speed to rise from zero to the specified rotation speed. Therefore, the blower does not perform the phase control but performs only the phase control of the electromagnetic pump. In general, control for changing the fuel flow rate in accordance with the air flow rate is performed.

However, if the fuel is supplied while maintaining the optimum air-fuel ratio with the rise of the blown air amount to make it difficult to incompletely burn, there is a relation that the ignition sound becomes large due to the rapid rise of the combustion. In order to reduce the noise, the fuel flow is slightly deviated from the optimum air-fuel ratio and the increase in the fuel flow is delayed, so that the exhaust gas is not so bad and the ignition sound can be tolerated. Therefore, starting the ignition operation while the blower is operating during the after-purge time greatly reduces the balance between the amount of the blown air and the fuel. Therefore, in the Japanese Patent Publication No. 7-109301, the emergency stop operation of the blower is performed. It is proposed to perform the normal ignition operation from the state where the blower fan is stopped or near the stop.

[0008] In the case of controlling only the fuel flow rate without controlling the amount of air blow as described above, the reliability for suppressing the generation of ignition sound, odor, smoke, and the like is inferior. Some things did not fit, and some kind of response was required.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has an electromagnetic pump 1 having a function of varying the flow rate of discharged fuel spray, and a blower capable of supplying an air amount corresponding to the variable fuel flow rate. 2 and a discharge igniter 3 that ignites the spray fuel by a spark to be discharged. The discharge igniter 3 that is operated by the ignition operation ignites when the spray fuel flow rate is smaller than a specified fuel flow rate, and discharges the spray fuel after ignition. In a soft-ignition device for a water heater that increases to a prescribed fuel flow rate, a blower control means 4 is provided, which is energized to a blower 2 in conjunction with an ignition operation, and thereafter is re-energized through an inertial blow operation by non-energization. 1 is provided with an ignition phase control means 5 for gradually increasing the fuel spray pressure to reach a specified fuel flow rate and constituting an ignition control device for igniting during the inertial air blowing operation of the blower 2. A.

Further, the blower 2 is provided with a rotation speed detecting means 6, which drives the electromagnetic pump 1 by the phase control means 5 when a predetermined rotation speed is detected during the inertial blowing operation. After a predetermined time, the blower 2 is instructed to re-energize, so that the blower 2 can be accurately ignited during the inertial blowing operation.

The blower 2, which is energized in conjunction with the ignition operation, is provided with a blower control means 4 for re-energizing through an inertial blow operation by non-energization after a short time brake operation.
By igniting during the inertial air blowing operation, the fuel flow rate and the air blowing amount suitable for the ignition can be balanced in a short time, and the entire ignition time can be shortened.

[0012]

According to the present invention, the blower 2 is energized together with the ignition operation to increase the blown air amount to a specified amount. However, the operation of the electromagnetic pump 1 is not balanced with the rise of the blown air amount, and the blower 2 is ignited. Is temporarily stopped, and the phase control of the electromagnetic pump 1 is performed such that the amount of air and the amount of fuel in the middle of the reduction due to inertial air blowing become optimal for ignition and the fuel is ignited. Blowing was not forcibly performed to the combustion chamber of the water heater, so that the maximum pressure of the combustion chamber could be kept low, and ignition noise and vibration were reduced.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to an embodiment of a heater shown in the drawing. Reference numeral 1 denotes an electromagnetic pump for supplying fuel to a burner 7, and 8 denotes a spray which sprays fuel pressurized by an electromagnetic pump in a mist state. The nozzle 3 is a discharge igniter whose tip is disposed in front of the spray nozzle 8, and 2 is a blower for supplying combustion air to the burner 7.

4 is a blower control means for the blower 2 and 5 is an electromagnetic pump 1 for controlling the flow rate of fuel supplied to the burner 7.
9 is a discharge igniter 3 and a blower control means 4.
A burner controller for controlling the phase control means 5, and the burner controller 9 is preferably operated by the blower control means 4 and the phase control means 5 so that the air and the fuel sent to the burner 7 maintain the optimum air-fuel ratio. Allow complete combustion.

Reference numeral 10 denotes a combustion chamber into which the flame of the burner 7 is blown, 11 denotes a heat exchange chamber following the combustion chamber 10, 12 denotes an exhaust pipe for discharging combustion exhaust gas passing through the heat exchange chamber 11, and 13 denotes a combustion chamber 10 This is a water chamber that constitutes a can body of a water heater that covers the outside of the heat exchange chamber 11, and the water chamber 13 is provided with a water supply pipe 13a and a hot water supply pipe 13b.

Reference numeral 14 denotes ignition means for instructing the burner controller 9 to start the oil hot water heater, 15 denotes fire extinguishing means for instructing the operation of the oil hot water heater to stop, and 16 denotes the temperature of hot water in the water chamber 13 of the hot water heater. When the water heater is started by the ignition means 14, the burner controller 9 starts the operation of the burner 7 while detecting the hot water temperature by the hot water temperature detection means 16, and the hot water temperature detection means 16 When the temperature is detected, the operation of the burner 7 is stopped. Since the inside of the water chamber 13 is heated to a constant temperature in this manner, the water supply pipe 1
The water sent from 3a becomes hot water and can be taken out from hot water supply pipe 13b.

In an oil water heater equipped with such a pressure spray burner, ignition can be performed even when a specified fuel / air flow rate is sent to the burner 7 during an ignition operation. However, if specified combustion is performed immediately after ignition, it is limited. The internal pressure of the combustion chamber 10 in the closed space becomes high immediately after ignition, and the combustion start sound called “dawn” and vibration,
It also produces smoke and odor. As a countermeasure, the amount of fuel sent to the spray nozzle 8 by the phase control means 5 of the electromagnetic pump 1 or the blow control means 4 of the blower 2 is reduced immediately after the ignition operation, and an air amount capable of igniting even with this small fuel flow rate is obtained. By controlling
A soft ignition device that ignites when the amount of combustion is small and suppresses a rise in the pressure of the combustion chamber 10 has been put to practical use.

However, in order to perform fine control such as phase control on both the air amount and the combustion amount, it is necessary to interlock with some kind of sensor means. Accurately interlocking with large rising fluctuations is a very difficult control. For this reason, the conventional control utilizes the delay in the rise of the amount of air when the blower is energized, and realizes an increase in the fuel flow rate similar to the increase in the amount of air by the phase control, which is smaller than the specified flow rate. At times, soft ignition was realized by controlling the balance of the fuel and air amounts optimal for ignition, but it was not applicable to all pressure spray burners.

The present invention realizes silent ignition despite simple air blowing control. The operation of the air blowing control means 4 energizes the air so as to have a specified air blowing amount together with the ignition operation, and the rotation of the air blower 2 increases. After that, the power supply is stopped, the inertial air blowing operation is performed, and then the power supply is started again. On the other hand, the operation of the phase control means 5 of the electromagnetic pump 1
The supply of fuel is controlled so that the amount of air during the inertial air blowing operation in which the amount of air blows decreases becomes a balance suitable for ignition, and after ignition, the fuel flow rate is increased in response to the increase in the amount of air of the blower 2 that has been energized. It will increase.

As described above, the inertial air blowing operation is performed at the ignition point, and the air is not forcibly blown when the pressure of the combustion chamber 10 increases at the time of ignition. Therefore, the ignition sound is reduced, and after the ignition, the blower is turned on again. The combustion air is supplied by 2 to prevent incomplete combustion from occurring.

As a specific embodiment, reference numeral 6 denotes a rotation speed detecting means attached to a blower motor or the like of the blower 2, and operates the phase control means 5 when the rotation speed of the blower 2 decreases to a predetermined rotation speed. By starting the supply of fuel, the ignition point can be specified during the inertial blowing operation of the blower 2, and the blower 2 can be re-energized a predetermined time after the rotation speed detecting means 6 has been activated. Thus, the operation of the blower 2 can be started immediately upon ignition. For this reason, even when the fuel flow rate is small, the ignition point can be reliably specified and ignition can be performed, and the generation of ignition sound, vibration, odor, and smoke of the oil hot water heater can be extremely reduced.

Further, the quieting of the ignition sound is caused when the fuel flow rate is low, that is, when the air flow rate is reduced by inertial air blowing. Therefore, when aiming for a small fuel flow rate, the operation of the blower 2 is stopped. A considerable amount of time has passed since. The blower control means 4 according to the embodiment of the present invention stops the energization of the blower 2 after performing a brake operation for supplying a half-wave DC to the blower 2 for a short time before performing the inertial blow operation. The amount of air blown can be reduced in a short time, and the time from ignition operation to completion of ignition can be shortened.

If the fan 2 is provided with the rotation number detecting means 6, the brake operation may be performed until a predetermined rotation number is detected, and then the energization of the fan 2 may be stopped. Even when the number of rotations at which the operation was performed was considerably reduced, the ignition could be accurately performed at an appropriate time in combination with the operation control of the electromagnetic pump 1.

Reference numeral 17 denotes a pressure sensor provided in the flow path of the combustion gas. If ignition of the blower 2 is delayed after the ignition during the inertial blowing operation, incomplete combustion may occur.
When the pressure sensor 17 detects the pressure increase, it is the time when ignition is possible. Therefore, by starting the operation of the blower 2 by the signal of the pressure sensor 17, when the blower 2 with good response is used, incompleteness after the ignition is used. It can eliminate combustion.

Further, in the case of the pressure spray burner, if the spraying of the fuel is continued while the ignition has failed, a serious trouble will occur. Therefore, a photoconductive cell made of Cds is attached and the completion of the ignition is detected by light to determine the ignition. Most burners have a system that operates safely when no light can be detected within this time. For this reason, a structure may be adopted in which ignition is performed during inertial blowing and the blower 2 is energized as soon as the photoconductive cell detects light. In this case, it is not necessary to newly add a special sensor, so that the cost increases. It can be handled without any problem.

It should be noted that the main point of the present invention is to provide an ignition point during inertial air blowing. However, it has been found that the amount of air blowing does not increase immediately after energization depending on the air blower, and there is a case where there is a delay. Therefore, even if the blower 2 is energized at the same time as or before the ignition, the state of the air is still substantially the same as that of the inertial air, and the air volume needs to be increased immediately after the ignition. Therefore, depending on the characteristics of the blower 2, the operation of the present invention is more realized when the start time of energization is shifted before the time of ignition without using the pressure sensor 17 or the photoconductive cell described above. In some cases it can be successful.

[0026]

As described above, according to the present invention, instead of providing an ignition point at the rising of the blower of the blower 2 as in the conventional oil water heater, the energization of the blower 2 is stopped and the inertial blow operation is performed. Since the ignition point is provided when the amount of air blown by the blower 2 decreases, the combustion noise and vibration at the time of ignition become extremely small, and a quiet oil hot water heater can be obtained.

Further, since the blower 2 starts blowing again when the ignition is ignited, after the ignition, the fuel flow corresponding to the blowing amount is supplied in the same manner as when the conventional blower 2 starts to blow air. The incomplete combustion of the gas was suppressed, and the odor and smoke at the time of ignition were eliminated.

Further, in order to detect a decrease in the amount of air blown after the power supply to the blower 2 at the time of ignition is stopped, a rotation speed detecting means 6 of the blower 2 is provided, and the operation of the electromagnetic pump 2 is controlled by this signal. In addition, even if the degree of reduction in the amount of air blown during inertial air blow varies due to various conditions of the oil hot water heater, ignition can be performed under optimum conditions.

Further, when it takes time to reduce the air volume to the desired air volume of the blower 2 only by inertial air blow, if the brake operation is performed after the blower 2 is de-energized, this time can be greatly shortened. This contributes to shortening of the ignition time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an oil water heater according to an embodiment of the present invention.

FIG. 2 is a graph showing a relationship between an air blowing amount and a fuel flow rate according to the embodiment of the present invention.

FIG. 3 is a graph showing a relationship between an air blowing amount and a fuel flow rate according to another embodiment of the present invention.

FIG. 4 is a cross-sectional view of an oil water heater showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electromagnetic pump 2 Blower 3 Discharge igniter 4 Blow control means 5 Phase control means 6 Revolution detection means

Claims (3)

[Claims] 1. An electromagnetic pump 1 having a function of varying a flow rate of a discharged fuel spray, a blower 2 capable of supplying an air amount corresponding to the variable fuel flow rate, and a discharge igniter for igniting the spray fuel by a spark to be discharged. A discharge igniter 3 operated by an ignition operation, ignites when the sprayed fuel flow rate is less than a specified fuel flow rate, and increases the sprayed fuel to the specified fuel flow rate after ignition. 2 is a blower control means 4 which is energized in conjunction with the ignition operation and thereafter re-energizes through an inertial blow operation by non-energization.
And an electromagnetic pump 1 is provided with an ignition phase control means 5 for gradually increasing a fuel spray pressure to reach a specified fuel flow rate, and an ignition control device for an oil water heater for igniting during an inertial blowing operation of the blower 2. 2. A blower 2 is provided with a rotation speed detecting means 6,
The rotation speed detection means 6 drives the electromagnetic pump 1 by the phase control means 5 from the time when the predetermined rotation speed is detected during the inertial air blowing operation, and instructs re-energization of the blower 2 after a predetermined time, and 2. The ignition control device for an oil hot water heater according to claim 1, wherein the ignition is performed during the air blowing operation. 3. A blower 2 energized in conjunction with an ignition operation
The ignition control device for an oil hot water heater according to claim 1, further comprising: a blower control means (4) for re-energizing through an inertial blow operation by non-energization after a minute time brake operation, and igniting during the inertial blow operation of the blower (2).