JP3855919B2 - Combustion device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combustion apparatus that generates a spark by generating a spark discharge with respect to fuel supplied into a combustion chamber to generate a flame, and burns the combustion chamber with the generated flame.
[0002]
[Prior art]
Conventionally, in a hot water supply apparatus to which the above combustion apparatus is applied, a heat exchanger and a combustor are provided in the combustion can body, and the heat exchanger is heated by the combustor, whereby water flowing into the heat exchanger is supplied. The hot water is made to flow out to the outside (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Publication No.2-1818
[0004]
[Problems to be solved by the invention]
In such a water heater combustor, as an example, oil (kerosene) is ejected in a mist form from a nozzle, while sparks are generated by discharge to ignite the oil and detect flames in the combustion can body. Combustion is started when a flame detector (for example, a phototransistor) detects a flame.
[0005]
The combustion can body is provided with a heat insulating material made of, for example, silica (silicon dioxide) on the inner surface for the purpose of increasing the combustion efficiency in the can body. Further, the combustion can body may be provided with a baffle plate made of, for example, stainless steel for scattering a flame caused by fuel ejected from the nozzle. The baffle plate and the heat insulating material are red hot by the flame during combustion. For example, the red heat may remain for a while after the combustion.
[0006]
If such a red-hot state remains, the flame detector erroneously detects the flame even though there is no flame. At that time, when the user performs a tapping operation again, the flame detector However, since it is determined that the flame has been erroneously detected and the ignition has been performed, the ignition operation (that is, the start of combustion) is not immediately performed in the combustion chamber in response to the tapping operation. Therefore, if the hot water discharge operation is performed again immediately after the combustion is stopped, combustion is not immediately started, and combustion is started after the non-flame state is confirmed by the flame detector. It becomes a factor which causes the undershoot of so-called tapping temperature, such as being lowered. In addition, since a combustion instruction is issued in response to an erroneous determination that combustion is in progress due to erroneous detection of a flame, an error process for stopping the combustion operation may occur in some cases.
[0007]
DISCLOSURE OF THE INVENTION
The present invention has been conceived under the circumstances described above, and provides a hot water supply apparatus that can prevent an undershoot of a hot water temperature caused by erroneous detection of a flame detector and erroneous error processing. This is the issue.
[0008]
In order to solve the above problems, the present invention takes the following technical means.
[0009]
  A hot water supply apparatus provided by the present invention includes ignition means for igniting a fuel supplied into a combustion chamber by generating a spark discharge, and flame detection for detecting a flame generated by ignition by the ignition means. And a combustor for combusting the combustion chamber with the generated flame.Combustion start control means for starting combustion by the combustor based on a detection result by the flame detection means;A first discriminating means for discriminating whether or not a predetermined first predetermined time has elapsed after the combustion by the combustor is stopped;A second determination unit configured to determine whether or not a combustion time by the combustor is equal to or longer than a predetermined second predetermined time; and an input unit configured to input a combustion start; and the combustion start control unit is configured by the input unit. When the start of combustion is input, the second determination means determines that the previous combustion time by the combustor is equal to or longer than a second predetermined time, and the first determination means determines the first predetermined time after the previous combustion stop. When it is determined that the time has elapsed, the combustion by the combustor is started regardless of the detection result by the flame detection means.It is characterized by that.
[0010]
  According to this invention,When the combustion start is input by the input means, it is determined that the previous combustion time is equal to or longer than the second predetermined time, andWhen it is determined that the first predetermined time has elapsed since the last stop of combustion, combustion by the combustor is started regardless of the detection result by the flame detection means (for example, a flame detector comprising a phototransistor). That is, when it is determined that the first predetermined time (for example, 15 seconds) has elapsed since the previous combustion stop, for example, the baffle plate or the heat insulating material provided in the combustion can body continues to be red hot. In such a case, even if the flame detection means erroneously detects red heat, it is immediately ignited to burn the combustion chamber. Therefore, even when the user performs the hot water operation again immediately after the combustion is stopped, the combustion operation is started immediately, so that an undershoot of the hot water temperature can be prevented.
[0013]
  GoodAccording to a preferred embodiment,The ignition means supplies the fuel after a lapse of a first time after starting the spark discharge, ignites at a second time following the first time, and a third time following the second time. The spark discharge is stopped after a lapse of time,When combustion is started by the combustion start control means, when spark discharge is generated by the ignition means,The second time is lengthened compared to the case where the combustor is burned based on the detection result by the flame detection means.Time control means is provided.
[0014]
  According to the present invention, when a spark discharge is generated by the ignition means when ignoring the flame detection result by the flame detection means and starting combustion,Increasing the second time that is ignited by generating a spark discharge for the supplied fuel. Ie flame detectionmeansWhen igniting by ignoring the flame detection result, do not check the ignition means by the flame detection result.ButCompared to the normal operation that does not ignore the flame detection result by the flame detector,Long second timeBy settingSince the state in which a spark discharge is generated with respect to the supplied fuel becomes longer in time and the possibility of ignition in the second time increases,The certainty of ignition by the ignition means can be ensured.
[0015]
  According to another preferred embodiment,The time control means includesThe combustionstartWhen combustion is started by the control means,When spark discharge is generated by the ignition means, compared to the case where the combustor is burned based on the detection result by the flame detection means,The thirdofTimeLengthen.
[0016]
  According to this invention, flame detectionmeansWhen ignoring the flame detection result byWhen a spark discharge is generated by the ignition means, the second timeThe third to continue to generate spark discharge followingofTimeLengthen. Ie flame detectionmeansIgnoring the result of flame detection and causing combustionwhen, Flame detectionmeansCompared to normal operation that does not ignore the flame detection resultsThe second3ofBy setting the time to be longer,Since the state ignited in the second time is continued in the third time, the ignition state is likely to be stable,While ensuring the certainty of ignition by the ignition means, the flame holding effect can be further enhanced.
[0017]
According to another preferred embodiment, the feed water temperature detecting means for detecting the temperature of the supplied water, the hot water temperature detecting means for detecting the temperature of the hot water heated in the combustor, and the combustion When a predetermined time has elapsed from the start of combustion by the combustor, when the temperature of the water detected by the feed water temperature detecting means and the temperature of the hot water detected by the hot water temperature detecting means are within a predetermined temperature difference, the combustion by the combustor Combustion stop means for stopping the combustion.
[0018]
According to the present invention, when a predetermined time elapses from the start of combustion by the combustor, the temperature of the water detected by being supplied with water and the temperature of the hot water detected by being heated in the combustor are within a predetermined temperature difference. Since the combustion by the combustor is stopped, when the combustion operation is started in the red hot state, the relationship between the temperature of the supplied water and the temperature of the hot water heated by the combustor is confirmed. Therefore, it is possible to reconfirm that the combustion is performed, and it is possible to secure safety.
[0019]
Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the accompanying drawings.
[0021]
FIG. 1 is a diagram showing an overall configuration of an embodiment of a hot water supply apparatus according to the present invention.
[0022]
The hot water supply device is connected to the combustion can body 2, the combustor 3 provided on the upper portion of the combustion can body 2, the heat exchanger 4 provided on the lower portion of the combustion can body 2, and the lower end of the combustion can body 2. An exhaust pipe 5, a water supply unit 6 for supplying water to the heat exchanger 4, a hot water supply unit 7 for supplying hot water from the heat exchanger 4 to the hot water tap 12, and a part of the water supplied from the water supply unit 6 to the hot water supply unit 7 A water supply bypass unit 8 that guides the fuel, a fuel supply unit 9 that supplies oil fuel such as kerosene to the combustor 3, and a hot water supply control unit 101 that controls the hot water supply operation of the hot water supply device.
[0023]
The combustion can body 2 has a hollow, substantially rectangular parallelepiped shape and forms a copper box, and a heat insulating material 22 is provided on the inner surface. The heat insulating material 22 is made of, for example, alumina (aluminum oxide) and silica (silicon dioxide). The combustion can body 2 has a combustor 3 attached to an upper portion thereof, and an exhaust pipe 5 bent in an L shape is connected to a lower end thereof. A wind pressure switch 51 for detecting the wind pressure of the outside air is provided at a suitable position outside the tip of the exhaust tube 5. The combustion can body 2 constitutes a chamber in which oil is combusted by the combustor 3, and constitutes a chamber that transmits heat generated by the combustor 3 to the heat exchanger 4. A ribbon-like shape for dispersing the flame so that the flame generated in the combustor 3 does not directly hit the heat exchanger 4 at a predetermined position facing the lower end of the combustor 3 in the upper portion of the combustion can body 2. A baffle plate 21 is provided. A heat exchanger 4 (fin tube heat exchanger) composed of a copper tube 42 having a plurality of fins 41 protruding from the peripheral surface at a predetermined interval is attached to the lower part of the combustion can body 2. 4 is connected to a water supply pipe 61 constituting the water supply section 6, and a water supply pipe 71 constituting the hot water supply section 7 is connected to the water discharge end of the heat exchanger 4.
[0024]
The combustor 3 includes a nozzle 31 for spraying oil in a mist, a pair of electrode rods 32 for igniting the oil sprayed from the nozzles, and an ignition for generating a spark discharge by applying a high voltage between the pair of electrode rods 32. A transformer 33, a blower fan 34 made of, for example, a sirocco fan for supplying air to the combustion chamber 2a, a rotation speed sensor 35 for detecting the rotation speed of the blower fan 34, and a phototransistor for detecting whether or not the combustor 3 is burning. 36 and a burner high limiter 37 for detecting that an abnormality has occurred in the combustion of the combustor 3 due to the back wind from the exhaust pipe 5. The nozzle 31, the electrode rod 32, the phototransistor 36 and the burner high limiter 37 of the combustor 3 are disposed on the upper end face of the combustion can body 2, and the blower fan 34 is disposed on the upper end of the combustion can body 2 via the blower path. Has been.
[0025]
The combustor 3 drives the blower fan 34 to send air to the combustion chamber 2 a of the combustion can body 2, and sprays oil (kerosene) from the nozzle 31 into the combustion chamber 2 a to form a mist, and a pair of electrode rods 32. When a high pressure is applied to the spark and a spark is generated by discharge, the oil is ignited and combustion starts. When a flame is generated by igniting oil, the color of the flame is usually detected by the phototransistor 36, and combustion by the combustor 3 is started based on this detection signal.
[0026]
The heat generated by the combustion of the combustor 3 heats the fins 41 of the copper pipe 42 provided at the lower part in the combustion chamber 2a, and this heat is transmitted to the water flowing through the copper pipe 42 to generate hot water. Further, the combustion gas generated by the combustion of the combustor 3 is discharged to the outside through the combustion cylinder 5. When strong wind is generated in the outside air and the air flows back to the combustion chamber 2a of the combustion can body 2 through the exhaust cylinder 5, the flame of the nozzle 31 flows back to the blower fan 34 side, and an abnormal combustion state is caused. Abnormal combustion is detected by the burner high limiter 37, and the combustion of the combustor 3 is forcibly stopped based on this detection signal.
[0027]
The oil supply unit 9 employs a method (so-called return method) in which a part of the supplied oil is collected and joined to the oil supplied from the oil source to supply the oil to the nozzle 31. The oil supply unit 9 includes a first oil pipe 91 that supplies oil from the oil source, a second oil pipe 92 that supplies oil to the nozzle 31, a third oil pipe 93 that returns a part of the oil supplied from the nozzle 31 to the oil supply side, A control valve 94 provided at a connection point between the three oil pipes 93 and the first oil pipe 91, and controls the amount of oil supplied to the nozzle 31 via the second oil pipe 92 by adjusting the amount of return oil that returns through the third oil pipe 93. The oil temperature thermistor 95 is provided upstream of the control valve 94 of the third oil pipe 93 and detects the temperature of the oil to be recirculated, and is provided at the tip of the first oil pipe 91 to control the supply of oil from the oil source. And an electromagnetic pump 97 provided at the base end of the second oil pipe 92 for supplying oil to the nozzle 31 with a predetermined pressure.
[0028]
When the electromagnetic valve 97 is opened, the oil supply unit 9 is supplied to the nozzle 31 with the oil supplied from the oil source being pressurized to a predetermined pressure by the electromagnetic pump 97. Part of the oil supplied to the nozzle 31 is used for combustion, and the rest is returned through the third oil pipe 93 and then returned to the second oil pipe 92 again. The temperature of the oil returned via the third oil pipe 93 is detected by the oil temperature thermistor 95, and based on this temperature, the oil is returned via the third oil pipe 93 that joins the oil supplied from the oil source by the control valve 94. The amount of oil is adjusted. That is, the viscosity of the oil changes depending on the temperature, and the amount of oil per unit time flowing through the second oil pipe 92 changes. Therefore, the amount of oil supplied to the second oil pipe 92 is appropriately adjusted by the control valve 94.
[0029]
The water supply unit 6 includes a water supply pipe 61 made of a copper pipe that guides water supplied from a water tank (not shown) to the heat exchanger 4, and a filter that filters the supplied water provided at the base end of the water supply pipe 61. 62, a can body water amount sensor 63 that is provided downstream of the water flow branch point of the water supply pipe 61 and detects the amount of water supplied to the heat exchanger 4, and is provided at an appropriate position downstream of the can body water amount sensor 63. A water thermistor 64 that detects the temperature of the water flowing through the water supply pipe 61 is provided.
[0030]
The hot water supply section 7 is provided at a suitable location upstream from the junction of the hot water supply pipe 71 made of a copper pipe for guiding the hot water supplied from the heat exchanger 4 to the hot water tap 12 and the bypass pipe 81 of the hot water supply pipe 71. A can body water amount servo 72 that controls the amount of water flowing in the hot water supply pipe 71, a can body thermistor 73 that is provided at an appropriate downstream side of the can body water amount servo 72 and detects the temperature of the hot water flowing through the hot water supply pipe 71, and the hot water supply pipe 71. A hot water thermistor 74 for detecting the temperature of hot water discharged from the hot water tap 12 is provided at a position downstream of the junction with the bypass pipe 81.
[0031]
The water supply bypass unit 8 is provided with a bypass pipe 81 made of a copper pipe for guiding a part of the water supplied from the water supply pipe 61 to the hot water supply pipe 71, and a bypass that controls the amount of water flowing through the bypass pipe 81. A water volume servo 82 and a bypass water volume sensor 83 that detects the water volume of the bypass pipe 81 are provided at an appropriate position on the upper volume side of the bypass water volume servo 82. A hot water stirring mechanism 11 for stirring water and hot water is provided at the junction of the bypass pipe 81 and the hot water supply pipe 71 so that the temperature of the hot water led to the hot water tap 12 is uniform.
[0032]
When the hot-water tap 12 is opened, the water supplied from the water storage tank is constituted by the water supply pipe 61, the heat exchanger 4, and the hot water supply pipe 71, and the water supply pipe 61, the bypass pipe 81, and the hot water supply pipe 71. And is discharged from the hot water tap 12. When the amount of water detected by the can body water amount sensor 63 exceeds the minimum operating flow rate (MOQ) for the hot water supply device to start the hot water supply operation, the combustion operation of the combustor 3 is started and hot water is supplied from the heat exchanger 4. Will come to be. When combustion is started, the combustion amount of the combustor 3 changes in accordance with the amount of water flowing through the heat exchanger 4, so the amount of water flowing through the heat exchanger 4 is the amount of water in the can body so as not to exceed the combustion capacity of the combustor 3. It is automatically adjusted by the servo 72. Further, the temperature of the hot water supplied from the heat exchanger 4 is detected by a can body thermistor 73, and the combustion operation of the combustor 3 is controlled based on the detected temperature and the combustion capacity, so that the temperature of the hot water supply pipe 71 is a predetermined value. Held at temperature.
[0033]
On the other hand, the temperature of hot water supplied from the hot water tap 12 is detected by the hot water thermistor 74, and the water supplied to the hot water agitating mechanism 11 by the bypass water amount servo 82 based on this detected temperature and the hot water temperature set by the user. The amount is controlled. That is, the amount of hot water from the heat exchanger 4 and the amount of water to be mixed are automatically adjusted by the bypass water amount servo 82, whereby hot water at the tapping temperature set from the hot water tap 12 is stably supplied.
[0034]
The hot water supply control unit 101 is mainly composed of an electronic circuit such as a microcomputer, and performs overall control of the hot water supply operation described above. Although not shown, hot water supply control unit 101 is communicably connected to a remote controller (hereinafter referred to as a remote controller) for remotely operating a hot water supply device by a two-core wire, and based on operation information transmitted from the remote controller. To control the hot water supply operation.
[0035]
FIG. 2 is a block configuration diagram related to hot water supply control of the hot water supply apparatus according to the present invention.
[0036]
This figure is a block diagram of a configuration in which a remote controller is connected to the hot water supply apparatus. Block 100 has a configuration on the hot water supply apparatus side, and block 200 has a configuration on the remote control side. In the hot water supply apparatus side block 100, the same members as those shown in the overall configuration diagram of FIG. Since the same members as those shown in the overall configuration diagram of FIG. 1 have been described above, detailed description thereof will be omitted in the following description.
[0037]
The hot water supply apparatus side block 100 and the remote control side block 200 are connected by a communication line 300 composed of two core wires, and a drive power supply (DC power supply) is supplied from the hot water supply apparatus side block 100 to the remote control side block 200 via the communication line 300. In addition, necessary data is communicated between the hot water supply apparatus side block 100 and the remote control side block 200. For data communication, for example, an AM modulated wave (AM modulated wave in which digital data 0 and 1 are replaced with presence or absence of a predetermined carrier) by AM modulation of a predetermined carrier by an ASK (Amplitude Shift Keying) method is used for the communication line 300. This is done by superimposing it on the DC power supply supplied above.
[0038]
In the hot water supply device block 100, a control unit (hot water supply control unit) 101 controls the hot water supply operation of the hot water supply device, and is mainly composed of a microcomputer that incorporates a CPU 101a, ROM 101b, RAM 101c, and timer 101d in one chip. Yes.
[0039]
The CPU 101a controls the operation of the entire hot water supply apparatus by executing a control program stored in the ROM 101b. The ROM 101b stores a control program for the CPU 201a, default data necessary for executing the control program, and the like. The RAM 101c provides a work area for the CPU 101a to execute the control program, and temporarily stores the control program read from the ROM 101b and various data generated by the execution of the control program. In particular, in the present embodiment, the RAM 101c stores an A flag indicating whether or not the combustion time has continued for a predetermined time (for example, 1 minute), as will be described later. For example, the A flag is set to “1” when the combustion time continues for a predetermined time, and is set to “0” when the combustion time does not continue for the predetermined time.
[0040]
As will be described later, when there is combustion for a predetermined time (for example, 1 minute) or more during the previous combustion and within a predetermined time (for example, 15 seconds) since the previous combustion stop, the control unit 101, for example, the phototransistor 36 Regardless of the detection result of, control is performed to start combustion. The timer 101d is used when measuring the predetermined time.
[0041]
The communication unit 102 controls data communication with the remote controller 200. The communication unit 102 superimposes a carrier wave generation circuit that generates a predetermined carrier wave, a modulation circuit that AM-modulates the carrier wave with the data input from the control unit 101 by the ASK method, and a DC modulated power that is input from the power supply unit 104 And an output circuit for outputting to the remote control side block 200 via the communication line 300, a demodulation circuit for demodulating data from the AM modulated wave transmitted from the remote control side block 200 via the communication line 300, and the like.
[0042]
The EEPROM 103 is a non-volatile memory that stores data necessary for the control operation of the control unit 101 (data different from the data stored in the ROM 101b). Default data is also stored in the EEPROM 103. For example, information (ID code or the like) for specifying a product of the hot water supply device, information such as a repair history is stored.
[0043]
The power supply unit 104 includes, for example, a switching power supply, and generates drive power (DC voltage power) for each circuit in the hot water supply apparatus side block 100 and each circuit in the remote control side block 200 from, for example, a 100V AC power supply.
[0044]
Next, in the remote control side block 2, the control unit 201 controls the operation of the remote control, and is mainly composed of a microcomputer in which the CPU 201a, the ROM 201b and the RAM 201c are built in one chip. Control.
[0045]
The CPU 201a controls the operation of the entire remote controller by executing a control program stored in the ROM 201b. The ROM 201b stores a control program for the CPU 201a, default data necessary for executing the control program, and the like. Also. The RAM 201c provides a work area for the CPU 201a to execute the control program, and temporarily stores the control program read from the ROM 201b and various data generated by executing the control program.
[0046]
The communication unit 202 controls data communication with the hot water supply apparatus side block 100. The communication unit 202 is a carrier wave generation circuit that generates a predetermined carrier wave, a modulation circuit that AM modulates the carrier wave by the ASK method with digital data input from the control unit 201, and outputs an AM modulated wave to the water heater via the communication line 300 Output circuit, a power supply separation circuit that separates the AM modulated wave transmitted from the hot water supply apparatus side block 100 via the communication line 300 and the drive power supply, a demodulation circuit that demodulates data from the AM modulated wave, and the like.
[0047]
The EEPROM 203 is a non-volatile memory that stores data necessary for the control operation of the control unit 201 (data different from the data stored in the ROM 201b).
[0048]
The operation unit 204 mainly inputs operation information for remote operation of the hot water supply apparatus. The operation unit 204 is, for example, an operation button for operation on / off, hot water supply temperature, bath water amount and bath water level setting, bath automatic operation mode setting, and the like. The main component is a switch that converts the data into the control unit 201 and converts it into the control unit 201. The operation buttons are provided on the operation panel of the remote controller.
[0049]
The display unit 205 displays information such as the operation content of the operation unit 204 and the operation state of the hot water supply device. The display unit 205 is composed of, for example, a liquid crystal display or a fluorescent display tube, and is provided on the operation panel of the remote controller similarly to the operation buttons.
[0050]
Next, the control operation in the hot water supply apparatus will be described with reference to the flowcharts shown in FIGS.
[0051]
First, when a power switch (not shown) is turned on by a user operation, the A flag stored in the RAM 101c is set to “0” (S1). That is, when the power switch is turned on, the A flag is set to “0” on the assumption that no combustion has occurred for a predetermined time Ta (described later) or longer.
[0052]
Next, it is determined whether or not the operation switch (not shown) is turned on by the user's operation (S2). When the operation switch is turned on (S2: YES), the water supply pipe 61 is output based on the output from the can body water amount sensor 63. It is determined whether or not the amount of water flowing in the tank is equal to or greater than the MOQ (minimum working water amount) (S3). In the following description, it is said that the MOQ is turned on when the amount of water is equal to or greater than the MOQ, and the MOQ is turned off when the amount of water is equal to or less than the MOQ.
[0053]
In step S3, if the MOQ is off (S3: NO), it is determined whether or not a predetermined time Tb (for example, 15 seconds) has elapsed (S4). If the predetermined time Tb has elapsed (S4: YES), The process returns to the setting process for setting the A flag to “0”. If the predetermined time Tb has not elapsed (S4: NO), the operation switch on / off control process of step S2 is returned to. That is, in these processes, as described later, when the combustion is performed for a predetermined time Ta (for example, 1 minute) or more at the previous combustion, for example, the baffle plate 21 and the heat insulating material 22 provided in the combustion can body 2 are used. Assuming that it is red hot, it is determined whether or not the red hot state continues by determining whether or not a predetermined time Tb (for example, 15 seconds) has elapsed in step S4. That is, if the predetermined time Tb has elapsed after the previous combustion stop (S4: YES), it is determined that the red-hot state has been released, while if the predetermined time Tb has not elapsed (S4: NO), It is judged that the red hot state continues.
[0054]
On the other hand, if the MOQ is on in step S3 (S3: NO), it is determined whether or not the A flag stored in the RAM 101c is “0” (S5). When the A flag is “0” (S5: YES), that is, when the combustion is not performed for a predetermined time Ta or more during the previous combustion, it is determined whether or not a flame is detected by the phototransistor 36 (S6). When no flame is detected (S6: YES), the oil source solenoid valve 96 is opened, the electromagnetic pump 97 and the ignition transformer 33 are operated, oil is ejected from the nozzle 31, and a high pressure is applied to the electrode rod 32 to discharge. To generate a spark. This ignites the oil (S7).
[0055]
In step S6, when the flame is detected by the phototransistor 36 (S6: NO) and the detection time continues for a predetermined time Tc (for example, 20 seconds) (S8: YES), an error notification is given that the phototransistor 36 has erroneously detected. Perform (S9). Specifically, for example, the display unit 205 of the remote controller displays that the phototransistor 36 has erroneously detected. In this case, error notification may be made by voice or the like.
[0056]
After ignition (S7), it is determined whether or not a predetermined time T2 (flame determination time, for example, 0.1 second) until the flame is stabilized has passed (S10), and when the predetermined time T2 has passed (S10: YES) Combustion is started (S11).
[0057]
Here, at the start of combustion, for example, the ignition transformer 33 and the electromagnetic pump 97 shown in FIG. 5 are controlled. That is, the control unit 101 turns on the ignition transformer 33 to generate sparks by discharging, and after a predetermined time T1 (referred to as “pre-ignition time”) has elapsed, turns on the electromagnetic pump 97 to eject oil from the nozzle 31. Next, a predetermined time T2 (flame determination time) until the flame stabilizes, waits (the time from when a spark is generated until the flame determination time ends is referred to as “ignition time”), so that the flame is generated reliably. To. Usually, the flame is detected by the phototransistor 36 during the flame determination time T2. Then, after the predetermined time T3 has elapsed, the ignition transformer 33 is turned off (this predetermined time T3 is referred to as “post-ignition time”).
[0058]
Returning to FIG. 3, when the A flag is “1” in step S <b> 5 (S <b> 5: NO), that is, combustion is performed for a predetermined time Ta or more at the previous combustion, and a predetermined time Tb (for example, 15 seconds) elapses. By the time the user has performed the hot water supply operation and the MOQ is turned on (S3: YES), the A flag is set to “0” (S12), and ignition is performed (S13).
[0059]
That is, in this case, the ignition operation is performed immediately, ignoring the flame detection result by the phototransistor 36. That is, when the combustion is performed for a predetermined time Ta (for example, 1 minute) or more at the time of the previous combustion, the baffle plate 21 and the heat insulating material 22 in the combustion can body 2 are in a red hot state, and the predetermined time Tb (for example, 15). Seconds), when the MOQ is turned on (S3: YES), it is assumed that the baffle plate 21 and the heat insulating material 22 continue to be red hot. In such a case, the phototransistor 36 However, the ignition is performed despite the fact that the red-hot state is erroneously detected and the flame is detected.
[0060]
Conventionally, if the hot water discharge operation is performed again immediately after the stop of combustion, the phototransistor 36 may erroneously detect the flame, and it is determined that it is in an ignited state. The hot water supply operation is performed without being burned, and when the hot water supply operation is performed again immediately after the combustion is stopped, the hot water temperature is lowered, which causes an undershoot of the hot water temperature. However, in this embodiment, the ignition detection is performed ignoring the detection result of the flame by the phototransistor 36, so that the combustion operation can be started immediately, and undershoot of the tapping temperature can be prevented. .
[0061]
  Thereafter, the control unit 101 determines whether or not a predetermined time T2 ′ (flame determination time, for example, 0.2 seconds) until the flame is stabilized has passed (S14), and when the predetermined time has passed (S14: YES) ), Combustion is started (S11). At this time, the flame determination time T2 ′ is set to be slightly longer than the flame determination time T2 after the A flag is determined to be “0” in step S10. That is, when ignition is performed ignoring the flame detection result by the phototransistor 36, ignition by the ignition transformer 33 is not confirmed by the flame detection result.ButBy setting the flame determination time T2 ′ longer than the normal operation in which the detection result of the flame by the phototransistor 36 is not ignored,Since the state in which a spark discharge is generated with respect to the supplied oil becomes longer in time and the possibility of ignition at the flame determination time T2 ′ increases,The certainty of ignition by the ignition transformer 33 can be ensured.
[0062]
Next (see FIG. 4), the control unit 101 determines whether the combustion mode is proportional combustion or on / off combustion (S15). If the combustion mode is proportional combustion (S15: YES), It is determined whether the MOQ is on and the A flag is “1” before combustion (S16). That is, when the combustion time is equal to or longer than the predetermined time Ta in the previous combustion and the MOQ is turned on immediately after the combustion is stopped (S3: YES), it is determined whether or not a predetermined time Td (for example, 50 seconds) has elapsed since the start of combustion. When the predetermined time Td has elapsed (S17: YES), the incoming water temperature detected by the incoming water thermistor 64 and the temperature of hot water heated in the heat exchanger 4 detected by the can body thermistor 73 are determined. Are compared to determine whether or not both temperature differences are equal to or greater than a predetermined temperature difference (for example, 5 ° C.) (S18). If the temperature difference is not equal to or greater than the predetermined temperature difference (S18: NO), that is, if the hot water temperature does not rise much after the predetermined time Td has elapsed from the start of combustion, the combustion operation is forcibly stopped (S19). Then, the A flag is set to “0” (S20), and the process returns to the MOQ on / off determination process in step S3.
[0063]
By these processes, if the phototransistor 36 has failed, if the temperature of the hot water does not rise so much even after the predetermined time Td has elapsed from the start of combustion, it is determined that no flame has come out and the combustion is forcibly stopped. . Therefore, even when the phototransistor 36 is out of order, combustion can be prevented and kerosene can be prevented from being continuously ejected.
[0064]
Further, as in the above control, when the temperature difference between the incoming water temperature and the hot water temperature is not equal to or greater than the predetermined temperature difference, the combustion is forcibly stopped and the MOQ on / off determination process (S3) is returned. Compared to the case where the user cannot reset the vehicle without resetting it after the safe operation, the software can be restarted without losing data (without being reset).
[0065]
In the above embodiment, the temperature of the hot water detected by the hot water thermistor 74 may be used instead of the temperature of the hot water heated in the heat exchanger 4. In step S18, the incoming water temperature is compared with the hot water temperature, but instead of this process, the hot water temperature heated in the heat exchanger 4 or the hot water temperature detected by the hot water thermistor 74 is temporally changed. Such a change may be used as a determination condition.
[0066]
In step S18, when both temperature differences are equal to or larger than the predetermined temperature difference (S18: YES), or in step S16, MOQ is on before combustion and the A flag is “0” (S16: NO). ), It is determined whether or not combustion for a predetermined time Ta (for example, 1 minute) is continued (S21). When the combustion for the predetermined time Ta is continued (S21: YES), the A flag is set to “1” (S22). That is, it is assumed that the baffle plate 21 and the heat insulating material 22 are red hot. If combustion for a predetermined time Ta is not continued (S21: NO), the A flag is set to “0” (S23). That is, it is assumed that the baffle plate 21 and the heat insulating material 22 are not red hot.
[0067]
If the A flag is set to “1” or “0” in steps S22 and S23, it is determined whether or not the MOQ is off (S24). If the MOQ is off (S24: NO), the user To determine whether or not the operation switch is turned off (S25). In step S24, if the MOQ is on (S24: YES), combustion is stopped (S26), and the process returns to step S3.
[0068]
If the operation switch is not turned off in step S25 (S25: NO), the process returns to the combustion mode determination process in step S15. When the operation switch is turned off (S25: YES), the process returns to the initial state of step S1.
[0069]
On the other hand, in the combustion mode determination processing in step S15, when the combustion is on / off combustion (S15: NO), it is determined whether or not the combustion on-time has elapsed (S27), and the combustion on-time has elapsed. In the case (S27: YES), it is subsequently determined whether or not the combustion off time has elapsed (S28). If the combustion off time has elapsed in step S28 (S28: YES), the process returns to step S15.
[0070]
Note that when ignition is performed, the post-ignition time T3 (see FIG. 5) after the flame determination time T2 until the flame is stabilized is ignored when the ignition detection is performed ignoring the detection result of the flame by the phototransistor 36. Compared to the normal operation in which the detection result of the flame by the transistor 36 is not ignored, it may be set longer. Specifically, as shown in FIG. 6, in step S10, after determining whether or not the flame determination time T2 until the flame is stabilized has elapsed, the post-ignition time T3 is set to 1 second, for example (S31). ). On the other hand, when ignition is performed ignoring the detection result of the flame by the phototransistor 36, in step S14, it is determined whether or not the flame determination time T2 ′ until the flame is stabilized has elapsed, and then post-ignition. Time T3 'is set to 3 seconds, for example (S32).
[0071]
  That is, when igniting by ignoring the flame detection result by the phototransistor 36, by setting the post-ignition time T3 ′ to be long,Since the ignition state at the flame determination time T2 ′ is continued at the post-ignition time T3 ′, the ignition state is likely to be stabilized.While ensuring the certainty of ignition by the ignition transformer 33, the flame holding effect can be further enhanced.
[0072]
Of course, the scope of the present invention is not limited to the embodiment described above. For example, in the above embodiment, the business-use hot water supply apparatus has been described, but the above-described control may be applied to a domestic hot water supply apparatus. The control in the above embodiment is a control that is used when immediate hot water supply is required when the hot water tap 12 is operated in a hot water supply operation or the like. For example, in a heat exchanger for bathing or hot water heating On the other hand, since immediate hot water supply is not required, the control may be performed with the A flag kept at “0”.
[0073]
【The invention's effect】
According to the present invention, at the time of the next combustion after the combustion stop by the combustor, when it is determined that the first predetermined time has not elapsed since the previous combustion stop, flame detection means (for example, a flame detector comprising a phototransistor) ) Combustion by the combustor is started regardless of the detection result. That is, when it is determined that the first predetermined time (for example, 15 seconds) has elapsed since the previous combustion stop, for example, the baffle plate or the heat insulating material provided in the combustion can body continues to be red hot. In such a case, even if the flame detection means erroneously detects red heat, it is immediately ignited to burn the combustion chamber. Therefore, even when the user performs the hot water operation again immediately after the combustion is stopped, the combustion operation is started immediately, so that an undershoot of the hot water temperature can be prevented. In addition, when the combustion operation is started in the red hot state, the combustion is surely performed by checking the relationship between the temperature of the supplied water and the temperature of the hot water heated by the combustor. It can be reconfirmed that it is possible to secure more safety.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of an embodiment of a hot water supply apparatus according to the present invention.
FIG. 2 is a block configuration diagram related to hot water supply control of a hot water supply apparatus.
FIG. 3 is a flowchart showing a control operation of a control unit of the hot water supply apparatus.
FIG. 4 is a flowchart showing a control operation of a control unit of the hot water supply apparatus.
FIG. 5 is a timing chart of turning on and off an ignition transformer and an electromagnetic pump during ignition.
FIG. 6 is a flowchart showing a modification of the control operation of the controller of the hot water supply apparatus.
[Explanation of symbols]
2a Combustion chamber
3 Combustors
21 Baffle plate
22 Insulation
33 Ignition transformer
97 Electromagnetic pump
36 Phototransistor
101 Control unit (hot-water supply device)
103 EEPROM

Claims (4)

Ignition means for igniting a fuel supplied into the combustion chamber by generating a spark discharge, flame detection means for detecting a flame generated by ignition by the ignition means, and the generated flame A combustion apparatus comprising: a combustor that combusts in a combustion chamber; and a combustion start control unit that starts combustion by the combustor based on a detection result of the flame detection unit ,
Input means for inputting the start of combustion;
First discriminating means for discriminating whether or not a predetermined first predetermined time has elapsed since the combustion by the combustor was stopped;
Second discriminating means for discriminating whether or not the combustion time by the combustor is a predetermined second predetermined time or more;
The combustion start control means includes
When the start of combustion is input by the input means, the second determination means determines that the previous combustion time by the combustor is equal to or longer than a second predetermined time, and the first determination means after the previous combustion stop The combustion apparatus starts combustion by the combustor regardless of the detection result by the flame detection means when it is determined that the first predetermined time has elapsed within a period of time . The ignition means supplies the fuel after a lapse of a first time after starting the spark discharge, ignites at a second time following the first time, and a third time following the second time. The spark discharge is stopped after a lapse of time,
When combustion is started by the combustion start control means, when the spark discharge is generated by the ignition means , the second time is compared with the case where the combustor is burned based on the detection result by the flame detection means. The combustion apparatus according to claim 1, further comprising a time control means for increasing the time. When the combustion start control means starts combustion and the spark start is generated by the ignition means , the time control means is compared with the case where the combustor is burned based on the detection result by the flame detection means. , lengthening the third time, the combustion device according to claim 2. Water supply temperature detection means for detecting the temperature of the water to be supplied;
Hot water temperature detecting means for detecting the temperature of hot water heated in the combustor;
When a predetermined time has elapsed from the start of combustion by the combustor, when the temperature of the water detected by the feed water temperature detecting means and the temperature of the hot water detected by the hot water temperature detecting means are within a predetermined temperature difference, the combustor The combustion apparatus according to any one of claims 1 to 3 , further comprising combustion stop means for stopping combustion by the combustion.

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