JP2007010248A - Ignition controller for oil water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ignition controller suppressing misfires and incomplete combustion after ignition in an oil water heater using a pressure atomizing burner. <P>SOLUTION: Fuel pressurized by an electromagnetic pump 1 is discharged like mist, a blower 2 is provided for supplying an air amount corresponding to the mist fuel, and a soft ignition device is composed to carry out ignition when the fuel and air amounts are smaller than specific amounts by discharge sparks of a discharge ignition system 3. In a discharge pressure of the electromagnetic pump 1 driven by a phase control means 4, after a fuel flow rate is increased to a set fuel flow rate higher than a specific flow rate, irrespective of success or failure of ignition, it is returned to the specific flow rate, and even if ignition fails at a point of soft ignition, ignition can be positively carried out when it is increased to the set fuel flow rate. When ignition is carried out at the point of soft ignition, by carrying out increase to the set fuel flow rate, flame can be stabilized, and combustion can be carried out without incomplete combustion. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a soft ignition control device that improves the ignition performance of an oil water heater.

  A pressure spray burner used as a heat source for an oil water heater sends to the burner the amount of air blown by the blower and the flow rate of fuel pressurized by an electromagnetic pump and blown from the spray nozzle, and sparks generated from the discharge electrode of the discharge ignition device Since the ignition and combustion are started instantaneously, the sound and vibration close to the explosion sound are generated at the time of ignition, and the odor and smoke related to incomplete combustion are generated.

  For this reason, the electromagnetic pump gradually increases the discharge pressure by means of energization control means such as phase control, and controls so as to obtain an air amount that can be ignited even with a small fuel flow rate, and ignites when the discharge pressure is low. After that, ignition control is performed in which the discharge pressure is gradually increased to a prescribed fuel flow rate to reduce explosion sound and odor at the time of ignition.

  When it is used for the first time after installation of a water heater or when fuel runs out, air is mixed in the fuel pipe from the electromagnetic pump to the spray nozzle. The fuel is not sprayed just by discharging air, and the burner stops due to an ignition mistake. When the operation is restarted by operating the reset switch or operation switch, the electromagnetic pump restarts, but the control to ignite the discharge pressure of the electromagnetic pump at a low pressure does not exhaust the air in the fuel pipe and starts combustion It takes time to complete.

  For this reason, normally, when the discharge pressure of the electromagnetic pump at the time of ignition is driven at a low pressure and the ignition cannot be detected after the ignition operation has started for a predetermined time, the discharge pressure of the electromagnetic pump is set to a pressure higher than the low pressure. There is a proposal that measures and holds the gas and reliably ignites by forcibly discharging the air accumulated in the fuel pipe (see Patent Document 1).

Japanese Patent Laid-Open No. 2005-9783

  In the conventional control described above, when the ignition is confirmed, the ignition operation is terminated and the control is shifted to the control during normal combustion. However, the pressure spray burner may be able to ignite even if air remains in the fuel pipe. In this case, since fuel mixed with air is sprayed after ignition, the inside of the burner is in an excess of air, and combustion may continue with incomplete flame formation, generating odor and noise.

  Further, when the temperature is low, the viscosity of the fuel increases, the particle size of the sprayed fuel increases, and the oxygen concentration in the air increases. For this reason, if a pressure spray burner is used when the temperature is low, normal spray cannot be formed and air with a high oxygen concentration is supplied, so that it is easy to cause ignition mistakes, and flame formation does not occur even when ignited. Occasionally, combustion continued to generate odor and noise.

  In addition, during the ignition operation, if the ignition cannot be confirmed, the ignition operation is repeated several times. However, the fuel may accumulate in the burner during the repetition of the ignition operation several times, and could be ignited several times. Sometimes the fuel accumulated in the burner burns and generates soot with a loud combustion noise.

  In addition, when an ignition error is caused by an abnormality in the ignition device, a large amount of fuel is accumulated in the burner if fuel is normally supplied while the ignition operation is repeated. It is a problem and a method of repeating the ignition operation many times is not preferable.

  The present invention solves the above-mentioned problem, and sprays by an electromagnetic pump 1 having a function of varying the discharge spray fuel flow rate, a blower 2 capable of supplying an air amount corresponding to the variable fuel flow rate, and a discharge spark. The discharge ignition device 3 that ignites the fuel is provided, and the discharge ignition device 3 that is operated by an ignition operation performs ignition when the sprayed fuel flow rate is lower than the specified fuel flow rate, and increases the sprayed fuel flow rate to the specified fuel flow rate after ignition. In the soft ignition device of a hot water heater, the electromagnetic pump 1 is provided with an ignition phase control means 4 that gradually increases the sprayed fuel flow rate to reach a set fuel flow rate, and setting of the electromagnetic pump 1 driven by the phase control means 4 is set. The fuel flow rate is set to be higher than the specified fuel flow rate, and the sprayed fuel flow rate after ignition is increased to the set fuel flow rate, and then returned to the specified fuel flow rate.

  Further, the soft ignition device is provided with ignition detection means 5 for detecting the presence or absence of ignition, and after the spray fuel flow rate of the electromagnetic pump 1 is increased to the set fuel flow rate, the electromagnetic pump is detected by the ignition detection output from the ignition detection means 5. The sprayed fuel flow rate of 1 is returned to the specified fuel flow rate, and the electromagnetic pump 1 increases up to the set fuel flow rate regardless of the presence or absence of ignition.

  Further, after the spray fuel flow rate of the electromagnetic pump 1 is increased to the set fuel flow rate, when the ignition detection means 5 detects ignition, the spray fuel flow rate of the electromagnetic pump 1 is kept at the prescribed fuel after holding the spray fuel of the electromagnetic pump 1 for a predetermined time T1. By returning to the flow rate, the flame can be stabilized even when air-mixed fuel is sprayed from the spray nozzle after ignition or even when the temperature is extremely low.

  Further, after the spray fuel flow rate of the electromagnetic pump 1 is increased to the set fuel flow rate, when the ignition detection means 5 does not detect the ignition, the spray fuel flow rate of the electromagnetic pump 1 is kept at the set fuel flow rate for a predetermined time T2, When the ignition is not detected within the predetermined time T2, the alarm means 6 is activated and the operation of the water heater is stopped. Even if the discharge pressure of the electromagnetic pump 1 is maintained at the set fuel flow rate for the predetermined time T2, the ignition is performed. When this is not possible, it is possible to inform the user of equipment malfunctions before a large amount of fuel accumulates in the burner.

  The soft ignition control of the pressure spray burner was able to ignite when the discharge pressure of the electromagnetic pump 1 was low, and to increase the fuel flow rate to the specified fuel flow rate after ignition, so that the combustion noise during ignition could be kept low. However, when air is accumulated in the fuel pipe or when the air temperature is low, the air is excessive, and it is easy to cause an ignition error. It was.

  In the present invention, the discharge pressure of the electromagnetic pump 1 is increased to a set fuel flow rate higher than a specified fuel flow rate that balances the air amount of the blower 2 and then returned to the specified fuel flow rate. Even if ignition is not possible at the point of soft ignition Since the ignition can be performed when the discharge pressure of the electromagnetic pump 1 is increased to the set combustion flow rate, there is almost no occurrence of an ignition mistake.

  Further, when the discharge pressure of the electromagnetic pump 1 is increased to the set fuel flow rate, the fuel flow rate increases with respect to the air amount. Therefore, after the excess air condition is eliminated and the flame is stabilized, the control during normal combustion is performed. Therefore, incomplete combustion no longer occurs when air remains in the fuel pipe or when the temperature is low.

  Further, after the discharge pressure of the electromagnetic pump 1 is increased to the set fuel flow rate, when the ignition detection means 5 can confirm the ignition, the discharge pressure of the electromagnetic pump 1 is returned to the specified fuel flow rate, thereby soft ignition. Regardless of the ignition at the point, the discharge pressure of the electromagnetic pump 1 is increased to the set fuel flow rate, so that it is possible to reliably prevent ignition errors and incomplete combustion after ignition without complicated control. It was.

  Further, after the discharge pressure of the electromagnetic pump 1 is increased to the set fuel flow rate, when ignition is confirmed by the ignition detection means 5, the discharge pressure of the electromagnetic pump 1 is kept at the set fuel flow rate for a predetermined time T1 and then specified. Since the fuel flow rate is restored, it is possible to shift to control during normal combustion after the flame is surely stabilized even when fuel mixed with air is sprayed after ignition or even when the temperature is low.

  In addition, after the discharge pressure of the electromagnetic pump 1 is increased to the set fuel flow rate, when no ignition is detected, the set fuel flow rate is maintained for a predetermined time T2 to forcibly discharge the air in the fuel pipe. It was possible to ignite reliably by one ignition operation. On the other hand, when ignition is not detected after the predetermined time T2, the hot water heater is stopped and the alarm means 6 is activated to notify the user of the device abnormality. When an ignition error is caused by this, the user can notice abnormally before a large amount of fuel is accumulated in the burner, and repairs can be easily performed.

  The present invention will be described with reference to an embodiment shown in the drawings. Reference numeral 7 denotes a burner serving as a heat source for a hot water heater, 8 denotes a fuel spray nozzle placed in the burner 7, and 9 denotes a fuel tank and a fuel spray nozzle 8 (not shown). 1 is an electromagnetic pump attached to the fuel pipe 9, 3 is a discharge ignition device having a tip disposed in front of the fuel spray nozzle 8, and 2 is a blower for supplying combustion air to the burner 7. .

  In the burner 7 of the oil water heater shown in FIG. 3, 10 is a blower cylinder to which combustion air is sent from the blower 2, 11 is a bottomed cylindrical combustion cylinder disposed in the blower cylinder 10, and 11 a is a bottom plate of the combustion cylinder 11. A fuel inlet 12 provided in the center is a swirl vane disposed on a bottom plate around the fuel inlet 11a. A fuel spray nozzle 8 is inserted into the fuel inlet 11a and is pressurized by the electromagnetic pump 1. The fuel is sent to the fuel spray nozzle 8 and is sprayed into the combustion cylinder 11 as a mist-like fuel. The combustion air of the blower 2 enters the combustion cylinder 11 from the air holes on the side wall of the combustion cylinder 11 and the swirl vanes 12. Supplied.

  13 is a blow control means for the blower 2, 4 is a phase control means of the electromagnetic pump 1 for controlling the flow rate of fuel supplied to the burner 7, 14 is a discharge ignition device 3, a blow control means 13, a phase control means 4, etc. The burner controller 14 is preferably operated by the air blow control means 13 and the phase control means 4 so that the air and fuel sent to the burner 7 can be completely burned while maintaining the optimum air-fuel ratio. ing.

  Reference numeral 5 denotes ignition detection means composed of CdS or the like for detecting the brightness of the combustion flame of the burner 7. The mist fuel sent from the fuel spray nozzle 8 is ignited by the discharge spark of the discharge ignition device 3, and the ignition detection means 5 When this is detected, the burner controller 14 stops the discharge of the discharge ignition device 3 and shifts to normal combustion control, and the flame after ignition is drawn to the swirl vane 12 to form a ring-shaped flame. Therefore, even if the discharge of the discharge ignition device 3 is stopped, the combustion flame can be maintained without interruption by the ring-shaped fire type.

  15 is a combustion chamber into which the flame of the burner 7 is blown, 16 is a heat exchange chamber following the combustion chamber 15, 17 is an exhaust pipe for discharging the combustion exhaust gas that has passed through the heat exchange chamber 16, and 18 is a combustion chamber 15 and a heat exchange chamber 16 is a water chamber that constitutes a can body of a water heater that covers the outside of the water tank 16, and a water supply pipe 18 a and a hot water discharge pipe 18 b are attached to the water chamber 18.

  19 is an ignition means for instructing the burner controller 14 to start the oil water heater, 20 is a fire extinguishing means for instructing the stop of the operating oil water heater, and 21 is a hot water for detecting the temperature of the hot water in the water chamber 18 of the water heater. When the hot water heater is started by the ignition means 19, the burner controller 14 starts the operation of the burner 7 while detecting the hot water temperature by the hot water temperature detection means 21, and the hot water temperature detection means 21 detects the set temperature. Then, the operation of the burner 7 is stopped. Thus, since the inside of the water chamber 18 is boiled to a constant temperature, the water sent from the water supply pipe 18a can be taken out from the hot water pipe 18b as warm water.

  An oil water heater equipped with such a pressure spray burner can be ignited even when a prescribed fuel / air flow rate is sent to the burner 7 during ignition operation. However, if prescribed combustion is performed immediately after ignition, a limited space is required. The internal pressure of the combustion chamber 15 becomes a high pressure immediately after ignition, and generates a combustion start sound and vibration called “dawn”, and smoke and odor. As a countermeasure, the amount of fuel sent to the fuel spray nozzle 8 by the phase control means 4 of the electromagnetic pump 1 or the airflow control means 13 of the blower 2 is reduced immediately after the ignition operation, and an amount of air that can be ignited even with this small fuel flow is obtained. By controlling in this way, a soft ignition device that is ignited when the amount of combustion is small and suppresses the pressure increase in the combustion chamber 15 has been put into practical use.

  By the way, when air is in the fuel pipe 9 immediately after installing the water heater or after running out of fuel, fuel mixed with air is sprayed from the fuel spray nozzle 8 at the time of ignition and cannot be ignited. is there. In particular, in the soft ignition device as described above, since the discharge pressure of the electromagnetic pump 1 at the time of ignition is low, it takes time until the fuel in the fuel pipe 9 is discharged and the fuel can be stably sprayed. It was necessary to operate many times before burning.

  The present invention solves the above-mentioned problem, and increases the discharge pressure of the electromagnetic pump 1 driven by the phase control means 4 at the time of ignition up to a set fuel flow rate, and then changes to a specified fuel flow rate. The discharge pressure of the set fuel flow rate is set higher than the specified fuel flow rate that balances the amount of air supplied at the rotation speed of the blower at the time of ignition. Therefore, fuel mixed with air is supplied at the time of ignition and ignition occurs at the point of soft ignition. Even if it is not possible, when the discharge pressure of the electromagnetic pump 1 increases to the set fuel flow rate, the air in the fuel pipe 9 that could not be discharged at the discharge pressure at the soft ignition point can be forcibly discharged. Stable mist-like fuel is sprayed, so it can be ignited reliably.

  The burner 7 may be able to ignite even when air remains in the fuel pipe 9, and when the ignition detection means 5 detects a combustion flame, it shifts to normal combustion control. In this case, however, air is mixed after ignition. Since the fuel is supplied, the balance between air and the air-fuel ratio of the fuel is lost, and the air becomes excessive.

  Further, the viscosity of the fuel used increases as the temperature decreases, and the oxygen concentration increases as the temperature decreases. For this reason, when the temperature during use is low, the spray particle size of the atomized fuel sprayed from the fuel spray nozzle 8 becomes large and the fuel is difficult to vaporize, and the oxygen concentration of the supplied air also becomes high. The air-fuel ratio of air and fuel is lost, resulting in an excess of air.

  When the burner 7 shifts to normal combustion with an excess of air, the combustion flame is not attracted to the swirl vane 12 and burns without forming a ring-shaped flame, causing incomplete combustion and generation of odor. And troubles such as increased combustion noise.

  In the present invention, when the discharge pressure of the electromagnetic pump 1 is increased to the set fuel flow rate, reading of the ignition detection means 5 is started, and when the flame detection signal is output from the ignition detection means 5, the specified fuel flow rate It has been changed to. For this reason, the electromagnetic pump 1 always increases to the set fuel flow rate when the ignition detection means 5 detects the ignition, and the fuel flow rate increases with respect to the air amount supplied by the blower 2. Even when ignited with air remaining or when the temperature is low, excess air can be eliminated, and the combustion flame can be reliably attracted to the swirl blades to form a ring-shaped flame Therefore, after the electromagnetic pump 1 is returned to the prescribed fuel flow rate and the normal combustion is started, incomplete combustion does not occur.

  As described above, the reading of the ignition detection means 5 is started after the fuel flow rate of the electromagnetic pump 1 is increased to the set fuel flow rate, so that the electromagnetic pump 1 always increases to the set fuel flow rate regardless of whether or not ignition occurs. Therefore, it is not necessary to perform complicated control, and the control device can be implemented without drastically changing.

  In another embodiment of the present invention, reference numeral 22 denotes a first timer which is operated by an output signal with a flame of the ignition detection means 5, and the electromagnetic pump 1 increases to a set fuel flow rate and the flame from the ignition detection means 5. When a certain signal is input, the electromagnetic pump 1 is held at the set fuel flow rate until the first timer 22 counts for a predetermined time T1, and the electromagnetic pump 1 is changed to the specified fuel flow rate by the count-up output of the first timer 22 Since the flame drawn to the swirl vane 12 after ignition is stabilized and then shifted to normal combustion, incomplete combustion can be reliably prevented.

  Reference numeral 23 denotes a second timer that operates with an output signal without flame from the ignition detection means 5, and when the signal without flame from the ignition detection means 5 is inputted when the electromagnetic pump 1 is increased to the set fuel flow rate, The electromagnetic pump 1 is held at the set fuel flow rate until the second timer 23 counts for a predetermined time T2, and the electromagnetic pump 1 holds the set fuel flow rate to discharge the air in the fuel pipe 9 once. Since the ignition operation can be surely ignited, it is not necessary to repeat the ignition operation many times as in the prior art, and the usability can be improved.

  Further, 6 is an alarm means that is activated when the water heater is abnormal. After the discharge pressure of the electromagnetic pump 1 has increased to the set fuel flow rate, the second timer 23 counts up without any flame output from the ignition detection means 5. When this occurs, the alarm means 6 is activated to notify the operator of the abnormality and the operation of the water heater is stopped.

  If the ignition is not detected even when the second timer 23 counts for the predetermined time T2, the ignition cannot be ignited due to the abnormality of the discharge ignition device 3, and the ignition operation is performed when the abnormality of the discharge ignition device 3 occurs. If the operation is repeated many times, a large amount of fuel is accumulated in the burner 7. However, in this control, the operator can immediately notice the abnormality of the discharge ignition device 3, and repair is performed before the fuel is accumulated in the burner 7. Can be easily handled.

It is a block diagram which shows the structure of the Example of this invention. It is a graph which shows the relationship between the ventilation volume and fuel flow volume of the Example of this invention. It is sectional drawing of the water heater which shows the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electromagnetic pump 2 Blower 3 Discharge ignition device 4 Phase control means 5 Ignition detection means 6 Alarm means

Claims (4)

An electromagnetic pump 1 having a function of changing the discharge spray fuel flow rate, a blower 2 capable of supplying an air amount corresponding to the variable fuel flow rate, and a discharge ignition device 3 for igniting the spray fuel by a discharge spark, The discharge ignition device 3 activated by the ignition operation ignites when the sprayed fuel flow rate is lower than the specified fuel flow rate, and in the soft ignition device of the water heater that increases the sprayed fuel flow rate to the specified fuel flow rate after ignition,
The electromagnetic pump 1 is provided with ignition phase control means 4 that gradually increases the fuel flow rate to reach the set fuel flow rate,
The set fuel flow rate of the electromagnetic pump 1 driven by the phase control means 4 is set to be higher than the specified fuel flow rate, the sprayed fuel flow rate after ignition is increased to the set fuel flow rate, and then returned to the specified fuel flow rate. A soft ignition control device for oil water heaters.   The soft ignition device is provided with ignition detection means 5 for detecting the presence or absence of ignition, and after the spray fuel flow rate of the electromagnetic pump 1 is increased to the set fuel flow rate, the electromagnetic pump 1 is detected by the ignition detection output from the ignition detection means 5. 2. The soft ignition control device for an oil water heater according to claim 1, wherein the sprayed fuel flow rate is returned to a prescribed fuel flow rate.   After the atomized fuel flow rate of the electromagnetic pump 1 is increased to the set fuel flow rate, when the ignition detection means 5 detects ignition, the atomized fuel flow rate of the electromagnetic pump 1 is held for a predetermined time T1, and then the atomized fuel flow rate is set to the specified fuel flow rate. The soft ignition control device for an oil water heater according to claim 1, wherein After the spray fuel flow rate of the electromagnetic pump 1 is increased to the set fuel flow rate, when the ignition detection means 5 does not detect ignition, the spray fuel flow rate of the electromagnetic pump 1 is maintained at the set fuel flow rate for a predetermined time T2, 2. The soft ignition control device for an oil water heater according to claim 1, wherein when no ignition is detected within time T2, the alarm means 6 is activated and the operation of the water heater is stopped.

Images