JP4085263B2 - Combustion device and hot water supply device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a combustion apparatus and a hot water supply apparatus, and more particularly to a combustion apparatus that can accurately determine and cope with an abnormality occurring inside the combustion apparatus, and a hot water supply apparatus using the combustion apparatus.
[0002]
[Prior art]
  Developed a combustion device that performs combustion control according to the type of gas supplied, such as city gas (natural gas) and propane gas, and a combustion device that directly detects the amount of gas supplied and performs optimal combustion control Has been.
[0003]
[Patent Document 1]
          Utility Model Registration No. 2584346
[0004]
  For example, Patent Document 1 discloses a combustion apparatus that automatically determines a gas type to be supplied by detecting a gas flow rate supplied to a burner by a gas flow rate detection unit and performs combustion control suitable for the gas type. Is disclosed.
[0005]
[Patent Document 2]
          Utility Model Registration No. 2600879
[0006]
  Patent Document 2 discloses a combustion apparatus in which a gas flow rate supplied to a burner is directly detected by a gas flow rate detection means, and combustion control is performed with high accuracy in accordance with a detected value.
[0007]
  By the way, in a hot water supply device incorporating such a combustion device, the heat exchange efficiency decreases due to factors such as clogging of the fins of the heat exchanger, clogging of the gas injection nozzle, or clogging of the gas exhaust pipe. The temperature may decrease. In addition, the gas supply pressure to the gas injection nozzle side may decrease with the deterioration of the gas on-off valve and gas flow control valve provided in the combustion device, resulting in a problem that the hot water supply temperature decreases. .
[0008]
  Therefore, in the conventional hot water supply apparatus, a gas pressure sensor for detecting the gas supply pressure to the gas injection nozzle is provided, and feedback control is performed on the gas supply pressure so as to stabilize the hot water supply temperature by compensating for a decrease in heat exchange efficiency. The structure which applies is adopted.
[0009]
  Further, unlike such a problem, there is a combustion apparatus that includes a plurality of burners and switches and supplies gas to the burners according to the amount of combustion to perform combustion. In such a combustion apparatus, since the flame rod for detecting the occurrence of flame is provided only in the vicinity of the ignition site, as the amount of combustion increases, when generating a flame with a burner away from the ignition site, After the gas supply to the burner is started, the heat transfer to the burner is confirmed by monitoring the increase in the calorific value.
[0010]
[Problems to be solved by the invention]
  However, in the above-described hot water supply apparatus that feedback-controls the gas supply pressure to the gas injection nozzle, the hot water supply temperature is stabilized, but depending on the factors that reduce the heat exchange efficiency, the deterioration of the gas burner or the like is promoted. It was.
[0011]
  In other words, as described above, when the gas supply pressure decreases due to deterioration factors such as a gas on-off valve and a flow rate control valve, the hot water supply temperature is stabilized by compensating the gas supply pressure to the gas injection nozzle side. It is possible.
  However, if heat exchange efficiency is reduced due to factors such as clogged fins in the heat exchanger, clogged gas injection nozzles, or exhaust blockage, compensation control is performed to increase the gas supply pressure to maintain the hot water supply temperature. As a result, the temperature of the gas burner is excessively increased, which leads to deterioration.
[0012]
  In other words, in the conventional hot water supply device, the gas supply pressure is controlled to stabilize the hot water supply temperature regardless of the factors that cause a decrease in heat exchange efficiency. Was invited.
  Further, although the gas pressure sensor for detecting the gas supply pressure has extremely high responsiveness, the gas pressure sensor is easily affected by temperature fluctuations and the like, and accurate combustion control cannot be performed.
[0013]
  In addition, in the hot water supply apparatus provided with the plurality of burners described above, since the fire transfer to the burner newly ignited with the increase in the combustion amount is confirmed by the heat generation amount based on the hot water supply temperature and the hot water supply flow rate, It took a long time to make improvements.
  Furthermore, the conventional hot water supply apparatus is not provided with a function of detecting gas leakage such as a gas flow path and a gas on-off valve due to deterioration of the apparatus, and improvement has been desired in terms of safety.
[0014]
  This invention is proposed in view of the said situation, and it aims at providing the combustion apparatus which improved durability, improving the reliability and safety | security by accurately discriminating the abnormal state of a combustion apparatus. . Another object of the present invention proposed at the same time is to provide a hot water supply apparatus using the combustion apparatus.
[0015]
[Means for Solving the Problems]
  Here, the gas mass flow sensor in the following description means the flow velocity (m / s) and density (g / m) of the gas flowing in the flow path.^Three ), That is, the mass of the gas flowing in the flow path per unit time. Therefore, even if the gas volume varies due to variations in temperature and pressure, the detection signal is not affected.
[0016]
  In order to achieve the above object, the present inventors have taken the following technical means.
  In other words, the invention according to claim 1 is a combustion apparatus including a gas mass flow sensor for detecting a gas supply amount to the gas burner, and the gas supply amount detected by the gas mass flow sensor for each combustion amount. A data table that correlates the amount of heat generated by the combustion device and the amount of heat generated by the combustion device is created in advance, and during combustion operation, the gas supply amount is sequentially detected by the gas mass flow sensor and the amount of heat generated by the combustion device is calculated and detected. When the amount of heat during combustion operation exceeds a predetermined allowable range with respect to the amount of heat stored in the data table corresponding to the gas supply amount, it is determined that the combustion is abnormal and a predetermined abnormality handling process is performed. ing.
[0017]
  Here, considering troubles occurring in the apparatus by taking a hot water supply apparatus incorporating the combustion apparatus of the present invention as an example, clogging of fins of a heat exchanger that transmits heat generated in the combustion apparatus to hot water or a gas burner Some parts of the gas injection nozzle are clogged, or exhaust blockage may occur in the exhaust cylinder.
[0018]
  When clogging of the fins of the heat exchanger occurs, the heat exchange efficiency decreases with a decrease in the heat exchange area, and the hot water supply temperature decreases. Further, when some of the gas injection nozzles are clogged, the heat exchange balance in the heat exchanger is lowered, the heat exchange efficiency is lowered, and the hot water supply temperature is lowered. Further, when the exhaust gas blockage occurs, the balance of the air-fuel ratio is lost, the heat exchange efficiency is lowered, and the hot water supply temperature is lowered.
  However, when such a trouble occurs, if control is performed to compensate for the decrease in the heat generation amount, the hot water supply temperature is maintained at a predetermined value, but the gas burner is partially overheated to promote deterioration of the apparatus. Results in.
[0019]
  On the other hand, even if any of the above problems occur, the amount of heat generated by the combustion device has a characteristic that the amount of heat generated by the combustion device decreases with respect to the gas supply amount detected by the gas mass flow sensor.
  The present invention discriminates a combustion abnormality by utilizing a characteristic that is caused by the trouble that occurs in such a combustion apparatus, and causes an abnormality compared to a control that simply compensates for a decrease in hot water supply temperature. Can be accurately determined and dealt with, and deterioration of the combustion apparatus can be prevented.
[0020]
  In the present invention, when a combustion abnormality is determined, abnormality handling processing such as abnormality notification may be performed immediately. It is also possible to perform the abnormality handling process when the combustion abnormality continues for a predetermined time, or when the combustion abnormality is repeatedly determined within a predetermined period and determined a predetermined number of times.
  In the present invention, the creation of the data table in which the detection signal of the gas mass flow sensor is associated with the amount of heat generated in the combustion apparatus is preferably at the time of laying where the deterioration of the combustion apparatus has not occurred. By creating a data table when the combustion apparatus is laid, the data table can be used as a basis for determining normal combustion operation.
[0021]
  According to a second aspect of the present invention, in the combustion apparatus according to the first aspect, a data table in which the gas supply amount detected by the gas mass flow sensor is associated with each combustion amount in advance is created, The combustion amount and the gas supply amount detected by the gas mass flow sensor are detected, and the detected gas supply amount is within a predetermined allowable range with respect to the gas supply amount stored in the data table corresponding to the combustion amount. When the value exceeds, the compensation control is performed so that the gas supply amount becomes the gas supply amount stored in the data table corresponding to the combustion amount.
[0022]
  Here, the combustion amount referred to in the present invention refers to a control amount that is variably controlled by the combustion device in accordance with the combustion operation state.
  Here, unlike the clogging of the fins of the heat exchanger described in claim 1, clogging of some gas injection nozzles, or exhaust blockage, all the gas injection nozzles are clogged substantially uniformly, Deterioration (clogging) of the gas flow path may occur. When such a malfunction occurs, in any case, the gas supply amount detected by the gas mass flow sensor with respect to the combustion amount decreases.
[0023]
  When such a problem occurs, the gas supply amount to the gas burner itself decreases, so there is no possibility of causing deterioration of the combustion device even when compensation control for increasing the gas supply amount is performed.
  According to the present invention, when trouble occurs that the gas supply amount to the gas burner is reduced, that is, when all the gas injection nozzles are clogged substantially uniformly or clogged in the gas flow path, With reference to the table, the gas supply amount detected by the gas mass flow sensor is compensated and controlled, and the hot water supply temperature can be stabilized.
[0024]
  The invention described in claim 3 is a hot water supply device incorporating the combustion device according to claim 1, wherein the amount of heat generated in the combustion device is calculated based on the water supply temperature, the hot water supply temperature, and the water supply amount. Has been.
[0025]
  When the heat generated in the combustion device is exchanged with hot water, the temperature of the hot water rises. The amount of heat supplied to the hot water by heat exchange is given by a function having the feed water temperature, the hot water temperature, and the feed water amount as parameters. The amount of heat generated in the combustion apparatus is given as a function of the amount of heat supplied to the hot water and the conversion efficiency.
  Therefore, according to the present invention, the amount of heat generated in the combustion apparatus can be easily obtained by referring to the feed water temperature, the hot water supply temperature, and the feed water amount during the combustion operation. Accordingly, it is possible to accurately determine the combustion abnormality by comparing the detection signal of the gas mass flow sensor during the combustion operation with the generated heat amount while referring to the data table created in advance.
[0026]
[0027]
[0028]
  The combustion apparatus according to any one of claims 1 to 3 described above,A gas proportional control valve that adjusts and controls the gas supply amount to the gas burner, and a gas pressure sensor that is provided downstream of the gas proportional control valve and detects the gas pressure supplied to the gas burner, and for each combustion amount A data table in which the gas supply amount detected by the gas mass flow sensor is associated with the gas pressure detected by the gas pressure sensor is created in advance, and the gas supply amount and gas detected by the gas mass flow sensor are sequentially detected during combustion. The gas pressure detected by the pressure sensor is detected, and combustion is detected when the detected gas supply amount exceeds a predetermined allowable range with respect to the gas supply amount stored in the data table corresponding to the detected gas pressure. A configuration for performing a predetermined abnormality handling process by determining an abnormalityIt is also possible to do.
[0029]
  here,Configuration described aboveConsidering the problems that occur in the hot water supply device with an example of the combustion device, the heat exchanger fins that transfer the heat generated by the combustion device to the hot water are clogged, and the exhaust blockage and the intake blockage are blocked. May occur.
[0030]
  When the heat exchanger fins are clogged or the exhaust gas is blocked, the downstream side of the flow path is constricted, and the gas burner is filled with gas. The supply amount decreases.
  In addition, when the intake blockage occurs, the gas pressure decreases slightly, whereas the gas supply amount increases as the air supply decreases.
[0031]
  Combustion apparatus having the above configurationIs for accurately discriminating combustion abnormality by using the characteristics that accompany the occurrence of such abnormality of the combustion apparatus, and it is possible to accurately determine the cause of the abnormality and cope with it.
[0032]
  Combustion apparatus having the above configurationWhen a combustion abnormality is determined, abnormality handling processing such as abnormality notification may be performed immediately. It is also possible to perform an abnormality handling process such as abnormality notification when a combustion abnormality is repeatedly determined a predetermined number of times.
  Also,Combustion apparatus having the above configurationIn this case, the data table in which the gas supply amount detected by the gas mass flow sensor and the gas pressure detected by the gas pressure sensor are associated with each other is preferably constructed when the combustion apparatus is not deteriorated. By creating a data table when the combustion apparatus is installed, the data table can be used as a basis for determining the normal operation state.
[0033]
  Of the above configurationHot water supply device with built-in combustion deviceIsThe gas injection amount per unit time is calculated from the gas pressure detected by the gas pressure sensor and the opening area of the gas injection nozzle. From the calculated gas injection amount and the mass of the supply gas per unit time detected by the gas mass flow sensor Calculates the specific gravity of the supply gas, calculates the total calorific value of the supply gas based on the feed water temperature, the hot water supply temperature, and the water supply amount, and determines the type of the supply gas based on the calculated specific gravity of the gas and the total calorific value. The combustion control is performed at the air-fuel ratio according to the determined gas type andIt is also possible to do.
[0034]
  The gas mass flow sensor can accurately detect the mass of the gas flowing in the flow path per unit time regardless of temperature and pressure fluctuations. Therefore, it is possible to accurately calculate the specific gravity of the gas.
  In addition, as described above, the amount of heat supplied to the hot water can be calculated by calculating the heat exchange efficiency with respect to the total heat generation amount, and the amount of supplied heat is calculated by a function using the water supply temperature, the hot water supply temperature, and the water supply amount as parameters. it can.
  Therefore, the total calorific value by the supply gas can be calculated using the feed water temperature, the hot water supply temperature, the feed water amount, and the heat exchange efficiency as parameters.
[0035]
  If the above configuration is adoptedThe type of the supply gas can be specified based on the calculated specific gravity of the gas and the total calorific value, and the combustion control can be performed at the optimum air-fuel ratio according to the determined gas type. The gas type can be determined at the time of trial operation such as when the hot water supply apparatus is laid or moved.
[0036]
[0037]
[0038]
  AboveWater heaterIsThen, the specific gravity and total calorific value of the gas during combustion are sequentially calculated and compared with a pre-stored value, and at least one of the calculated specific gravity and total calorific value of the gas is predetermined with respect to the pre-stored value. When exceeding the permissible range, it is determined that there is an abnormality in at least one of the gas mass flow sensor and the gas pressure sensor, and a predetermined abnormality handling process is performed.It is also possible to do.
[0039]
  The gas mass flow sensor and the gas pressure sensor are not directly exposed to the flame ejected from the gas burner, but are provided at a location close to the gas burner. For this reason, heating and cooling are always repeated, and the sensor itself is likely to be deteriorated.
  The above configurationFor example, when the hot water supply apparatus is laid, the specific gravity of gas and the total calorific value are calculated and stored in advance from detection signals from the gas mass flow sensor and the gas pressure sensor.
  Then, by comparing the specific gravity or total calorific value of the gas calculated during combustion with the stored value and determining the abnormality of the sensor, it is possible to accurately determine the abnormality of the sensor itself that is the basis of the abnormality determination. It becomes possible.
[0040]
  Claim4The invention described inThe combustion apparatus according to any one of claims 1 to 3.A combustion device that has a plurality of gas burners and performs combustion operation by switching and supplying gas to a predetermined gas burner according to the amount of combustion. Each combustion amount corresponds to a gas supply amount detected by a gas mass flow sensor. The gas data flow sensor detects the gas supply amount stored in the data table corresponding to the increased combustion amount when the combustion amount increases during combustion. During a period in which the supply amount exceeds a predetermined range, it is configured to determine that the ignition of a part of the burner to which gas supply is performed is incomplete.
[0041]
  Here, the gas burner referred to in the present invention refers to a combustion section composed of a single gas injection nozzle or a set of a plurality of gas injection nozzles, and the present invention further includes a plurality of gas burners composed of the plurality of gas injection nozzles. It has a configuration.
  Here, in a combustion apparatus that performs combustion operation by switching and supplying gas to a predetermined gas burner according to the combustion amount, when igniting a gas burner that has not been ignited as the combustion amount increases, The flame of the gas burner is transferred.
  At this time, before the gas burner to be ignited is ignited by fire transfer, that is, in an unignited state, the gas burner internal pressure does not increase due to the generation of flame accompanying ignition, and the gas supply amount increases. On the other hand, when the ignition is completed by transferring to the gas burner to be ignited, the gas burner internal pressure due to the generation of the flame rises and the gas supply amount becomes a steady state.
[0042]
  This change in the gas supply amount can be immediately detected as a detection signal of the gas mass flow sensor, and after the combustion amount is switched, the heat generation amount (a value calculated from the hot water supply temperature and the hot water supply flow rate) is referred to to determine the fire transfer. Compared with the case of performing the above, it becomes possible to perform accurate discrimination in a short time.
[0043]
  Claim5The invention described inThe combustion apparatus according to any one of claims 1 to 4,Detect gas supply to gas burnerGas mass flow sensorAnd a gas on / off valve that controls the opening and closing of the gas supply to the gas burner, wherein the gas on / off valve is closed and controlled.Gas mass flow sensorWhen the gas supply is detected by the above, it is determined that the gas on / off valve is leaked and a predetermined abnormality handling process is performed.
[0044]
  According to the present invention, gas leakage in the gas on-off valve can be easily detected, and the reliability of the combustion apparatus can be improved.
  In the present invention, when a gas leak is determined, an abnormality handling process such as an abnormality notification may be performed immediately, or when a gas leak is repeatedly determined a predetermined number of times, an abnormality handling process may be performed.
  The determination of gas leakage according to the present invention is preferably performed during a period other than during the combustion operation, for example, during pre-purge (pre-scavenging) or post-purging (post-scavenging).
[0045]
  Claim6The invention described in claim5The combustion apparatus described in 1) has a plurality of gas burners, and has a capacity switching valve that supplies gas by switching to each gas burner or each group according to the amount of combustion, and the gas on-off valve is closed. In a state where all the capacity switching valves are opened and controlled,Gas mass flow sensorWhen gas supply is detected bySaidWhile determining gas leakage in the gas on-off valve, while controlling the opening of the gas on-off valve and closing control of all the capacity switching valve,Gas mass flow sensorWhen the gas supply is detected by any one of the capacity switching valves, orGas mass flow sensorIt is configured to perform abnormality handling processing by discriminating gas leakage in the downstream gas flow path.
[0046]
  According to the present invention, it is possible to easily detect gas leakage on the downstream side of the gas on-off valve and any capacity switching valve or the gas flow rate sensor, and to improve the reliability of the combustion apparatus. it can.
  In the present invention, when a gas leak is determined, an abnormality handling process such as an abnormality notification may be performed immediately, or when a gas leak is repeatedly determined a predetermined number of times, an abnormality handling process may be performed.
  Also in the present invention, it is preferable to determine the gas leakage during a period other than during the combustion operation, for example, during pre-purge (pre-scavenging) or post-purge (post-scavenging).
[0047]
[0048]
  In the combustion apparatus of Claims 5 and 6,By using the gas mass flow sensor, a minute gas flow rate can be accurately detected as the mass of the flowing gas, and the occurrence of gas leakage at the initial stage can be accurately determined.
[0049]
  Claim7The invention described in claim5 or 6In the combustion apparatus described in 1), a gas proportional control valve is provided downstream of the gas on-off valve, and the gas proportional control valve includes a step motor and a needle valve.
[0050]
  According to the present invention, by controlling the step motor, the needle valve can be stably controlled from the substantially fully closed state to the fully open state, and precise gas supply can be performed according to the combustion amount. . In addition, the possibility of breakage such as a flow control valve using a diaphragm or the like is reduced.
[0051]
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments of the present invention will be described below with reference to the drawings.
[0052]
  (First embodiment)
  FIG. 1 is a flow path system diagram of a hot water supply apparatus 1 according to the first embodiment of the present invention, FIG. 2 is a schematic diagram showing an operation principle of a gas mass flow sensor employed in the hot water supply apparatus 1, and FIG. FIG. 4 is a graph showing the relationship between the detection signal of the gas mass flow sensor and the calorific value, FIG. 4 is a graph showing the relationship between the detection signal of the gas mass flow sensor during combustion and the calorific value after the predetermined period of use, FIG. Is a graph showing the relationship between the combustion amount (control amount) during combustion at the initial stage of laying and the detection signal of the gas mass flow sensor, and FIG. 6 is a graph showing the combustion amount (control amount) and the gas mass flow sensor after a predetermined period of use. 7 is a graph showing the relationship with the detection signal, FIG. 7 is a graph showing the fluctuation of the detection signal of the gas mass flow sensor according to the presence or absence of fire transfer, FIG. 8 is a flowchart showing the operation of the hot water supply operation, and FIG. The flow state of gas Is a be enlarged view.
[0053]
  The hot water supply apparatus 1 of the present embodiment has a basic function of supplying hot water at a set temperature, and in order to stably perform the hot water supply function, a function for determining combustion abnormality, a function for detecting a fire transfer when the amount of combustion increases, and It is characterized by having a gas leak detection function.
  In the description of the hot water supply apparatus 1, first, the hot water supply operation that is the configuration and basic functions will be described. In FIG. 1, the gas secondary pressure sensor 24 provided in the gas flow path 12 is employed in a second embodiment to be described later. In the present embodiment, a description will be given assuming that the sensor 24 is not provided.
[0054]
  (Configuration of hot water supply system)
  As shown in FIG. 1, the hot water supply device 1 has a configuration in which the combustion device 2 is built in, and has a hot water supply function of supplying hot water at a temperature set by the remote controller 11 by opening a hot water supply tap (curan) 8. .
  The combustion device 2 includes a control circuit unit 10 that supervises combustion control, a remote controller 11, a gas burner 9 (9a, 9b), and a blower 19, and is supplied via a gas flow path 12 (in this embodiment, city gas) (Natural gas)) is a device that generates a flame by burning.
  The hot water supply device 1 includes a combustion device 2 and includes a water supply channel 6, a hot water supply channel 7, and a heat exchanger 5, and heats water supplied through the water supply channel 6 with the heat exchanger 5. In this apparatus, heated hot water is discharged from a hot-water tap (caran) 8 through a hot-water supply channel 7.
[0055]
  If it demonstrates sequentially, the combustion apparatus 2 has the gas burner 9 in the downstream edge part of the gas flow path 12. FIG. In addition, from the upstream side of the gas flow path 12, a gas on / off valve 23 that controls the opening and closing of gas supply, a gas proportional control valve 17 that controls and controls the gas flow amount in the gas flow path 12, and a gas that detects the gas flow rate A mass flow sensor 18 is provided in order.
  The gas burners 9a and 9b are provided with a plurality of gas injection nozzles 14a and 14b. In the present embodiment, a group of gas injection nozzles 14a arranged in three rows and a group of gas injection nozzles 14b arranged in two rows are grouped, and the capacity switching valves 13a and 13b are provided for each group. It is connected to the downstream end of the gas flow path 12.
  That is, when the capacity switching valve 13a is opened, gas is injected from the group of gas injection nozzles 14a, and when the capacity switching valve 13b is opened, gas is injected from the group of gas injection nozzles 14b. Moreover, it is the structure by which gas is injected from all the gas injection nozzles 14a and 14b by opening both capability switching valves 13a and 13b.
[0056]
  The gas burner 9 is fixed inside and below the substantially rectangular parallelepiped box 3, and a gas flow path 12 connected to the gas burner 9 extends from the box 3 to the outside. In addition, a blower 19 that sucks air from the outside to the inside of the box 3 and supplies the air to the gas burner 9 is provided at the lower part of the box 3.
  The blower 19 includes a fan 19c, a motor 19a that rotationally drives the fan 19c, and a rotation detection sensor 19b that detects the number of rotations of the motor 19a. The control circuit unit 10 supplies the gas burner 9 with air according to the combustion amount by controlling and driving the motor 19a to maintain the detection signal of the rotation detection sensor 19b at a predetermined value according to the combustion amount.
[0057]
  Also, in the vicinity of the gas injection nozzle 14a of the gas burner 9a, a spark plug 15 for igniting the injected gas and a frame rod 16 for detecting the occurrence of flame are arranged close to the gas injection nozzle 14a. 3 is fixed.
[0058]
  A heat exchanger 5 is provided above the inside of the box 3, that is, above the gas burner 9, and an exhaust cylinder 4 is provided above the heat exchanger 5. The heat exchanger 5 includes a plurality of heat exchange fins 5a arranged in parallel at predetermined intervals, and attached with a heat exchange pipe 5b bent through the heat exchange fins 5a. The combustion generated by the gas burner 9 It has a function of exchanging heat of the gas with hot water flowing through the heat exchange pipe 5b through the heat exchange fins 5a.
  The upstream side of the heat exchanger pipe 5b extends to the outside of the box 3 and is connected to the water supply passage 6. The downstream side of the heat exchanger pipe 5b extends to the outside of the box 3 and is connected to the hot water supply passage 7. Yes.
[0059]
  The upstream end of the water supply channel 6 is connected to a water tap (not shown), and a flow rate sensor 20 for detecting the amount of water supply and a water supply temperature sensor 21 for detecting the water supply temperature are provided on the channel.
  On the other hand, a hot-water tap (caran) 8 is attached to the downstream end of the hot-water supply passage 7, and a hot-water supply temperature sensor 22 for detecting the temperature of hot water to be supplied is provided on the flow passage.
[0060]
  Here, the gas mass flow rate sensor 18 provided in the gas flow channel 12 is a sensor that measures the mass flow rate (flow velocity × density) of the gas flowing in the gas flow channel 12. That is, the gas mass flow sensor 18 is a sensor that measures the mass of the gas flowing in the gas flow path 12 per unit time by measuring (flow velocity × density) of the gas flowing in the gas flow path 12. .
[0061]
  As shown in FIG. 2, the gas mass flow sensor 18 is provided with an upstream temperature sensor 18b and a downstream temperature sensor 18c on the upstream side and the downstream side of the heater 18a, and an ambient temperature sensor 18d for detecting the temperature of the flowing gas. Configured. In a state where the gas does not flow, the detected temperatures of the upstream temperature sensor 18b and the downstream temperature sensor 18c are balanced and no detected temperature is generated. The detected temperature of the downstream temperature sensor 18c increases in accordance with the gas flow, and the detected temperature difference increases compared to the upstream temperature sensor 18b. The gas mass flow sensor 18 detects the mass of the flowing gas based on this principle.
  Compared with the gas flow sensor, the gas mass flow sensor 18 measures the mass of the gas flowing per unit time, so that the detection signal is not affected by the ambient temperature and pressure, and the minute flow rate is precisely measured. It is possible to detect.
[0062]
  Moreover, in this embodiment, the gas proportional control valve 17 provided in the gas flow path 12 is comprised with the needle valve (needle valve) 17b and the step motor 17a like FIG. Thereby, by controlling the step motor 17a and proportionally controlling the open / closed state of the needle valve 17b, it is possible to control from the substantially fully closed state to the fully open state with fine and precise control.
[0063]
  (Hot water supply operation of the hot water supply device)
  Next, the operation of the hot water supply operation of the hot water supply apparatus 1 of the present embodiment will be described with reference to FIG.
  In the present embodiment, the hot water supply device 1 is configured to perform a trial operation at the time of installation, but the operation of the trial operation will be described in detail in the combustion abnormality determination control described later.
[0064]
  When the hot-water tap (calant) 8 is opened, water flows to the hot-water supply channel 7 side through the water supply channel 6 and the heat exchanger 5, and the flow of water is detected by the flow rate sensor 20.
  When the control circuit unit 10 receives the detection signal of the flow sensor 20 as a combustion command signal, the control circuit unit 10 sends a drive signal to the blower 19 to perform pre-purging (pre-scavenging) for a predetermined time, and then opens the gas on-off valve 23. Then, the step motor 17a of the gas proportional control valve 17 is driven to supply gas to the gas burner 9 with a predetermined opening, and the opening of the capacity switching valve 13a is controlled.
[0065]
  The control circuit unit 10 energizes the spark plug 15 to ignite the gas injected from the gas injection nozzle 14a, and starts combustion control when it is determined that a flame is generated by the detection signal of the frame rod 16.
  When the combustion control is started, the control circuit unit 10 refers to the detection temperature of the hot water temperature sensor 22, that is, from the hot water tap 8 while referring to the detection signals of the water supply temperature sensor 21 and the flow rate sensor 20 and the set temperature of the remote controller 11. The combustion amount of the combustion apparatus 2 is feedforward controlled so that the temperature of the discharged hot water becomes the temperature set by the remote controller 11.
[0066]
  In other words, in the adjustment control of the combustion amount, the control circuit unit 10 controls the gas proportional control with reference to the detection signal of the gas mass flow sensor 18 so that the gas corresponding to the combustion amount is supplied to the gas burner 9. While controlling the valve 17, the motor 19 a of the blower 19 is driven so that the detection signal of the rotation detection sensor 19 b becomes a predetermined number of revolutions so that air supply corresponding to the combustion amount can be obtained.
  Thereby, the amount of combustion is adjusted so that the hot water supply temperature becomes the set temperature of the remote controller 11, and hot water is supplied from the hot water tap 8.
[0067]
  When the discharge amount of the hot-water tap 8 increases during hot water supply, the control circuit unit 10 detects an increase in the hot water supply amount by the flow sensor 20, increases the opening of the gas proportional control valve 17, and switches the capacity. The valve 13b is opened. Thereby, the flame of the gas injection nozzle 14a is transferred to the gas injected from the gas injection nozzle 14b and ignited, and combustion with an increased combustion amount is started.
[0068]
  On the other hand, when the hot-water tap 8 is closed, the control circuit unit 10 detects the stop of the combustion command based on the detection signal of the flow rate sensor 20, fully closes the gas on-off valve 23, and closes the capacity switching valves 13a and 13b. To do. Then, after the blower 19 is driven for a predetermined time to perform post purge (post scavenging), the driving is stopped and the combustion control is ended.
[0069]
  (Combustion abnormality discrimination control)
  Next, combustion abnormality determination control of the hot water supply device 1 of the present embodiment will be described.
  In the present embodiment, a test operation is performed when the hot water supply device 1 is installed, thereby performing a data table creation process necessary for determining a combustion abnormality. Therefore, prior to the description of the combustion abnormality determination control, the data table creation processing will be described with reference to FIGS.
[0070]
  After operating the remote controller 11 and starting a trial run, first, the opening degree of the hot-water tap 8 is set to a low state. Thereby, the control circuit unit 10 detects the feed water flow rate based on the detection signal of the flow rate sensor 20, and performs the combustion with the combustion amount corresponding to the feed water flow rate, while detecting the detection signal E of the gas mass flow rate sensor 18._L And calorific value S obtained by calculation_LAnd remember. Next, the opening degree of the hot water tap 8 is set to a high state. Thereby, the control circuit unit 10 performs the detection with the detection signal E of the gas mass flow sensor 18 while performing the combustion with the combustion amount corresponding to the feed water flow rate._H And calorific value S obtained by calculation_HAnd remember.
  Then, as shown in FIG. 3, the control circuit unit 10 generates the data table 1 that connects the obtained data and associates the detection signal of the gas mass flow sensor 18 with the calorific value obtained by the calculation. Remember.
  At the same time, the control circuit unit 10 detects the detection signal E of the gas mass flow sensor 18 as shown in FIG._L , E_H Combustion amount (control amount) G corresponding to_L , G_H The data table 2 in which the combustion amount (control amount) and the detection signal of the gas mass flow sensor 18 are associated with each other is generated and stored.
[0071]
  Here, the calorific value in the combustion device 1, that is, the amount of heat supplied to the hot water is calculated by the function shown in Equation 1. In Equation 1, the water supply temperature is a detection temperature of the water supply temperature sensor 21, the hot water supply temperature is a detection temperature of the hot water supply temperature sensor 22, the amount of water supply is a detection signal of the flow sensor 20, and the heat exchange efficiency is a constant.
    Supply heat amount = f (feed water temperature, hot water supply temperature, water supply amount, heat exchange efficiency) (Equation 1)
[0072]
  Therefore, as shown in the graph of FIG. 3, the control circuit unit 10 changes the combustion amount in the trial operation, and the detection signal of the gas mass flow sensor 18 for each combustion amount and the calorific value obtained by Equation 1 Is created.
  Further, as shown in the graph of FIG. 5, the control circuit unit 10 creates the data table 2 in which the combustion amount (control amount) and the detection signal of the gas mass flow sensor 18 are associated with each other.
[0073]
  Next, combustion abnormality determination control during normal hot water supply operation will be described with reference to the flowchart of FIG. The operation of the hot water supply operation is the same as that described above.
[0074]
  During the period when the flow rate sensor 20 detects the feed water flow rate, the control circuit unit 10 receives the detection signal as a combustion command signal and performs combustion control.
  During the combustion control, the control circuit unit 10 reads the detection signal of the gas mass flow rate sensor 18 and takes in the detection signals of the feed water temperature sensor 21, the hot water supply temperature sensor 22 and the flow rate sensor 20, and generates a calorific value based on the above equation 1. Is calculated (see steps 100 to 102 in FIG. 8).
[0075]
  The control circuit unit 10 refers to the data table 1 (FIG. 4), and generates a calorific value S1 in the initial state corresponding to the read detection signal E1 of the gas mass flow sensor 18, and a calorific value S1-Δa calculated in step 102. And compare.
  As a result of the comparison, when the difference in the heat generation amount is within the allowable range (less than Δb), the efficiency is small and the hot water temperature fluctuation is small, that is, the heat exchange fin 5a is clogged, and the gas injection nozzles 14a and 14b The process proceeds to step 105 on the assumption that there is no uneven clogging or exhaust blockage (see steps 103 and 104 in FIG. 8).
[0076]
  Next, the control circuit unit 10 resets the timer for measuring the predetermined time t, and refers to the data table 2 (FIG. 6), and the detection signal S1 of the gas mass flow sensor 18 in the initial state corresponding to the combustion amount G1. The read detection signal S1-Δc of the gas mass flow sensor 18 is compared. Then, the gas proportional control valve 17 is controlled so that the difference Δc becomes zero, the gas supply amount to the gas burner 9 is adjusted and controlled, and the combustion operation is continued (see steps 105 to 107 in FIG. 8).
  In other words, in this state, even if the gas supply amount to the gas burner 9 is reduced due to a decrease in the primary gas pressure, clogging of the gas flow path 12, deterioration of the gas proportional control valve 17, etc., the gas supply amount is compensated for control. This makes it possible to obtain a necessary amount of heat generation without causing deterioration of the gas burner 9 or the like.
[0077]
  On the other hand, in step 104, the control circuit unit 10 refers to the data table 1 (FIG. 4), compares the heat generation amount S1 in the initial state with the heat generation amount S1-Δa calculated in step 102, and determines the heat generation amount. When the difference Δa is equal to or greater than the permissible range (Δb), it is determined that an abnormal combustion state in which a decrease in heat exchange efficiency is increasing has occurred.
  The control circuit unit 10 starts a timer for measuring the predetermined time t, and repeats steps 100 to 104 to monitor the difference in heat generation amount. When the timer expires, necessary abnormality handling processing such as abnormality notification is performed.
[0078]
  In other words, in this state, it is determined that a combustion abnormality in which the heat exchange efficiency is significantly reduced due to clogging of the heat exchange fins 5a, uneven clogging of the gas injection nozzles 14a and 14b, exhaust plugging, or the like has occurred. Then, the abnormality handling process is performed (see steps 104 and 108 to 111 in FIG. 8).
[0079]
  (Fire transfer detection function)
  Next, the fire transfer detection function when the amount of combustion of the hot water supply device 1 is increased will be described. In the hot water supply apparatus 1 of the present embodiment, as described above, control is performed to increase or decrease the combustion amount according to the detection signal of the flow sensor 20. That is, when the combustion amount is low, only the capacity switching valve 13a is opened and flame is injected from the gas injection nozzle 14a. When the combustion amount increases, both the capacity switching valves 13a and 13b are opened and the gas injection nozzle 14a is opened. , 14b to inject a flame.
[0080]
  Therefore, when the combustion amount shifts from a low state to a high state, the flame ejected from the gas injection nozzle 14a is transferred to the gas ejected from the gas injection nozzle 14b and ignited.
  In the hot water supply apparatus 1 of the present embodiment, when the capacity switching valve 13b is opened with an increase in the combustion amount, the control circuit unit 10 refers to the data table 2 (FIG. 7), and the gas corresponding to the combustion amount G1. A detection signal S1 of the mass flow sensor 18 is obtained.
[0081]
  Since the back pressure due to the flame of the gas injection nozzle 14b is not generated in the state where the fire transfer is not completed, the detection signal of the gas mass flow sensor 18 is S1 + Δd, which is higher than that in the state where the fire transfer is performed. On the other hand, when the fire transfer to the gas injection nozzle 14b side is completed, the detection signal of the gas mass flow sensor 18 decreases to S1 in the steady state with the back pressure due to the flame.
  Therefore, the control circuit unit 10 determines the completion of the fire transfer to the gas injection nozzle 14b by detecting that the detection signal of the gas mass flow sensor 18 has decreased to S1.
[0082]
  (Gas leak detection control)
  Next, the gas leak detection control of the hot water supply device 1 will be described with reference to FIG.
  In the present embodiment, the gas leak detection control is performed during the post purge (post scavenging) process of the hot water supply device 1.
[0083]
  That is, in parallel with the post-purge process, the control circuit unit 10 controls the closing of the gas on-off valve 23 and opens the capacity switching valves 13a, 13b of the gas burners 9a, 9b as shown in FIG. 9 (a). In this state, the detection signal of the gas mass flow sensor 18 is monitored. If no gas flow is detected by the gas mass flow sensor 18, it is determined that no gas leakage has occurred in the gas on-off valve 23. However, in this state, when the gas flow is detected by the gas mass flow sensor 18, it is determined that the gas proportional control valve 17 has leaked gas, and necessary abnormality handling processing such as abnormality notification is performed. Note that the gas proportional control valve 17 employed in the present embodiment is configured to allow a slight gas flow even when the opening degree is minimum. Therefore, when the gas leakage of the gas on-off valve 23 is detected, the opening degree of the gas proportional control valve 17 is not adjusted.
[0084]
  Subsequently, as shown in FIG. 9B, the control circuit unit 10 controls the opening of the gas on-off valve 23 and closes the capacity switching valves 13a and 13b of the gas burners 9a and 9b. The detection signal of the sensor 18 is monitored. If no gas flow is detected by the gas mass flow sensor 18, it is determined that no gas leakage has occurred in the capacity switching valves 13 a and 13 b and the gas flow path 12 on the downstream side of the gas mass flow sensor 18. However, in this state, when the gas flow is detected by the gas mass flow sensor 18, the gas is detected in at least one of the capacity switching valves 13 a and 13 b or in the gas flow path 12 on the downstream side of the gas mass flow sensor 18. It is determined that a leak has occurred, and necessary abnormality handling processing such as abnormality notification is performed.
[0085]
  In the above description, the gas leak detection control is described as being performed during the post purge (post scavenging) process of the hot water supply device 1, but it is also possible to perform it during the pre purge (pre scavenging) process.
[0086]
  As described above, according to the hot water supply device 1 of the present embodiment, by monitoring the change in the relationship between the detection signal of the gas mass flow sensor and the amount of heat (heat generation amount), the heat exchanger fins are clogged and the gas injection nozzle is biased. It is possible to distinguish from deterioration such as clogging of the gas flow path or uniform clogging of the gas injection nozzle by detecting characteristics peculiar to clogging or exhaust blockage. As a result, it is possible to accurately determine an abnormal factor that causes deterioration of the apparatus while maintaining stable combustion.
[0087]
  In addition, by adopting the gas mass flow sensor, it is possible to immediately detect the fire transfer at the time of increase in the combustion amount that conventionally required a detection time.
  Furthermore, by using a gas mass flow sensor, a slight gas leak can be detected, and the reliability and safety of the apparatus can be improved.
  In addition, the gas proportional control valve has a configuration using a needle valve and a step motor, so it is more durable than a diaphragm, and the gas supply volume can be controlled precisely and precisely from almost fully closed to fully open. Is possible.
[0088]
  (Second Embodiment)
  Next, the configuration and operation of the hot water supply apparatus 1 ′ according to the second embodiment of the present invention will be described.
  The flow path configuration of the hot water supply device 1 ′ is the same as the configuration shown in FIG. FIG. 10 is a graph showing the relationship between the gas secondary pressure and the gas supply amount at the initial stage of the water heater 1, and FIG. 11 shows the gas secondary pressure and gas supply amount after a predetermined period of use of the water heater 1. FIG. 12 is a flowchart showing a process performed during the trial operation, and FIG. 13 is a flowchart showing a combustion abnormality determination process performed during the combustion operation.
[0089]
  The hot water supply apparatus 1 'of the present embodiment has the same basic structure as the hot water supply apparatus 1 (FIG. 1) shown in the first embodiment, but only has a gas secondary pressure sensor (gas pressure sensor). The point is different. In other words, the gas secondary pressure sensor 24 is added to the combustion device 2 ′ incorporated in the hot water supply device 1 ′. Accordingly, the same components are denoted by the same reference numerals, and redundant description is omitted.
  The gas secondary pressure sensor 24 is provided on the gas flow path 12 of the combustion apparatus 2 ′ and on the downstream side of the gas proportional control valve 17, and is supplied to the gas injection nozzles 14a and 14b of the gas burners 9a and 9b. Detects the gas pressure.
[0090]
  (Operation during trial operation)
  The operation at the time of trial operation of the hot water supply apparatus 1 ′ will be described with reference to FIGS.
  After operating the remote controller 11 and starting a trial run, first, the opening degree of the hot-water tap 8 is set to a low state. Thereby, the control circuit unit 10 detects the feed water flow rate based on the detection signal of the flow sensor 20, and performs the combustion with the combustion amount corresponding to the feed water flow rate, while detecting the detection signal P of the gas secondary pressure sensor 24._LAnd the detection signal S of the gas mass flow sensor 18_LAnd memorize. Next, the opening degree of the hot water tap 8 is set to a high state. Thereby, the control circuit unit 10 performs the combustion with the combustion amount corresponding to the feed water flow rate, and the detection signal P of the gas secondary pressure sensor 24._HAnd the detection signal S of the gas mass flow sensor 18_HAnd remember.
  Then, as shown in FIG. 10, the control circuit unit 10 connects the obtained data to obtain the gas secondary pressure detected by the gas secondary pressure sensor 24 and the gas supply amount detected by the gas mass flow sensor 18. The corresponding data table 3 is generated and stored (see step 120 in FIG. 12 above).
[0091]
  Next, the control circuit unit 10 calculates the gas volume flow rate based on Equation 3. However, in Equation 3, the gas secondary pressure is a detection signal of the gas secondary pressure sensor 24, and the nozzle opening area is the opening area of the gas injection nozzles 14a and 14b measured in advance. The gas volume flow rate is obtained as a function of the gas secondary pressure and the nozzle opening area (see step 121 in FIG. 12).
      Gas volume flow rate = f (gas secondary pressure, nozzle opening area) ... (Formula 3)
[0092]
  The control circuit unit 10 calculates and stores the specific gravity of the gas based on the equation 4 from the gas volume flow rate calculated by the equation 3 and the gas supply amount (gas mass) that is a detection signal of the gas mass flow sensor 18 ( (See step 122 in FIG. 12).
      Gas specific gravity = Gas mass / Gas volume flow rate ... (Formula 4)
[0093]
  Next, the control circuit unit 10 calculates the total calorific value per unit time by the supplied gas. Here, the total calorific value can be obtained as a function of the amount of heat supplied to the hot water. Therefore, the total calorific value is calculated as follows using the above-described formula 1 and formula 5 below, and the control circuit unit 10 stores the calculated total calorific value (see step 123 in FIG. 12 above).
    Supply heat amount = f (feed water temperature, hot water supply temperature, water supply amount, heat exchange efficiency) (1)
    Total calorific value = f (supplied heat amount) (5)
[0094]
  The control circuit unit 10 compares the specific gravity of gas and the total calorific value calculated by Equations 4 and 5 with the data for each gas type stored in advance, and determines the type (component) of the gas to be supplied. Remember. Then, the combustion control data of the determined gas type is selected from the combustion control data stored in advance for each gas type, and thereafter, the combustion control is performed based on the selected combustion control data (see FIG. 12 steps 124 and 125).
[0095]
  (Distinguishing control for abnormal combustion in hot water supply equipment)
  Next, combustion abnormality determination control during the hot water supply operation of the hot water supply apparatus 1 ′ will be described with reference to FIGS. Since the hot water supply operation of the hot water supply device 1 ′ is the same as that of the hot water supply device 1 of the first embodiment, the duplicated explanation is omitted.
[0096]
  During the period when the flow rate sensor 20 detects the feed water flow rate, the control circuit unit 10 receives the detection signal as a combustion command signal and performs combustion control.
  During the combustion control, the control circuit unit 10 reads the detection signal (gas supply amount) of the gas mass flow sensor 18 and the detection signal (gas secondary pressure) of the gas secondary pressure sensor 24 (see FIG. 13 above). Steps 130-132).
[0097]
  The control circuit unit 10 refers to the data table 3 (FIG. 11), obtains the gas supply amount S1 in the initial state corresponding to the read gas secondary pressure P1, and detects the gas supply amount S1 in the initial state. The gas supply amount S1−Δf or the gas supply amount S1 + Δh is compared.
  As a result of the comparison, when the gas supply amount is lower than the initial state and the difference Δf in the gas supply amount is within the allowable range (less than Δg), the efficiency is small and the fluctuation of the hot water supply temperature is small. Assuming that no clogging of 5a or exhaust blockage has occurred, the routine proceeds to step 135.
  Further, as a result of the comparison, when the gas supply amount is larger than the initial state and the difference Δh in gas supply amount is within the allowable range (less than Δi), the efficiency is small and the hot water temperature fluctuation is small. Assuming that no blockage has occurred, the routine proceeds to step 135 (see steps 133 and 134 in FIG. 13).
[0098]
  Next, the control circuit unit 10 resets a timer that counts the predetermined time t. Then, referring to the data table 3 (FIG. 11), the blower 19 or the gas proportional control valve 17 is corrected and controlled so that an initial gas supply amount S1 corresponding to the gas secondary pressure P1 is obtained. Combustion control is continued while maintaining the air-fuel ratio (see steps 135 and 136 in FIG. 13).
[0099]
  On the other hand, in step 134, the control circuit unit 10 refers to the data table 3 (FIG. 11), compares the gas supply amount S1 at the gas secondary pressure P1 in the initial state with the detected gas supply amount, and determines the gas When the supply amount is lower than S1 and the difference is within the allowable range (Δg or more), it is determined that the decrease in heat exchange efficiency is increasing. Further, when the gas supply amount increases from S1 and the difference is equal to or larger than the allowable range (Δi), it is determined that the fluctuation of the heat exchange efficiency is increased (see step 134 in FIG. 13 above).
[0100]
  The control circuit unit 10 starts a timer for measuring the predetermined time t, and repeats steps 130 to 134 to monitor the difference in gas supply amount. When the timer expires, necessary abnormality handling processing such as abnormality notification is performed.
  In other words, in this state, it is determined that a combustion abnormality with significantly reduced heat exchange efficiency has occurred due to clogging of the heat exchange fins 5a, exhaust blockage or intake blockage, and abnormality handling processing such as abnormality notification is performed. (See steps 130 to 134 and 137 to 140 in FIG. 13).
[0101]
  Further, the hot water supply apparatus 1 ′ of the present embodiment employs a configuration that can detect an abnormality in the gas mass flow sensor 18 and the gas secondary pressure sensor 24 itself.
  That is, the control circuit unit 10 reads the detection signal of the gas secondary pressure sensor 24 and the detection signal of the gas mass flow sensor 18 at an appropriate time during the combustion operation of the hot water supply device 1 ′, and stores the detection signal during the test operation. Compare with the data table 3 (FIG. 10).
  As a result of the comparison, when the relationship between the gas secondary pressure and the gas supply amount differs from the relationship stored in the data table 3 beyond the allowable range, the control circuit unit 10 determines whether the gas mass flow sensor 18 or the gas secondary flow It is determined that there is at least one abnormality in the pressure sensor 24, and abnormality handling processing is performed.
[0102]
  Further, at an appropriate time during the combustion operation, the control circuit unit 10 reads the detection signal of the gas secondary pressure sensor 24 and the detection signal of the gas mass flow sensor 18, and the equations 4 and 4 described in the operation at the time of the test operation are performed. Based on Equation 5, the specific gravity of gas and the total calorific value are calculated.
  Then, the specific gravity and total calorific value of the gas obtained during the combustion operation are compared with the specific gravity and total calorific value of the gas stored during the trial operation (see steps 122 and 123 in FIG. 13), and the difference exceeds the allowable range. When they are different, the control circuit unit 10 determines that there is an abnormality in at least one of the gas mass flow sensor 18 and the gas secondary pressure sensor 24 and performs an abnormality handling process.
[0103]
  As described above, according to the hot water supply apparatus 1 ′ of the present embodiment, by adopting a configuration in which the gas mass flow sensor and the gas pressure sensor (gas secondary pressure sensor) are combined, the heat exchanger fins are clogged or the exhaust gas is blocked. It is possible to detect a characteristic unique to the intake blockage and distinguish it from other abnormal factors. As a result, it is possible to accurately determine an abnormal factor that causes deterioration of the apparatus while maintaining stable combustion.
  In addition, by combining a gas mass flow sensor and a gas pressure sensor, it is possible to automatically determine the type of supply gas and perform combustion control at an air-fuel ratio corresponding to the gas type, thereby improving reliability and stability. An improved hot water supply apparatus can be provided.
  Note that the hot-water supply device 1 ′ of the present embodiment can also be provided with a fire transfer detection function and a gas leak detection function similar to those of the hot-water supply device 1 described in the first embodiment.
  Further, in the hot water supply device 1 ′ of the present embodiment, when the back wind is instantaneously blown from the exhaust tube 4 and the exhaust blockage occurs, the exhaust blockage is detected by the fluctuation of the rotation speed of the blower 19, and the blower 19 It is also possible to perform control to compensate for a decrease in heat exchange efficiency due to exhaust blockage by changing the rotational speed.
[0104]
  In the first and second embodiments described above, an example in which city gas (LNG: liquefied natural gas) is employed as the supply gas has been described. However, the present invention uses a gas of another component or propane gas. It is also applicable to.
  In the embodiment, the hot water supply apparatus having only the hot water supply function has been described as an example, but the present invention is not limited to such a configuration. For example, in addition to the hot water supply function, the present invention can be applied to a hot water supply apparatus having a bath dropping function, a cooking function, or a heating function.
[0105]
  In the above-described embodiment, the abnormality handling process is performed when the abnormal combustion state is detected continuously for a predetermined time. However, for example, the abnormality is detected when the abnormal combustion state is detected a predetermined number of times at a predetermined interval. It is also possible to adopt a configuration that performs a corresponding process.
  Further, in the above embodiment, the configuration for detecting the pressure (primary pressure) of the supply gas upstream from the gas proportional control valve is not particularly described, but the configuration is provided with the gas pressure sensor for detecting the primary gas pressure. By adopting, it is possible to more appropriately control the air-fuel ratio when the primary gas pressure is reduced.
[0106]
【The invention's effect】
  According to the first and second aspects of the invention, there is provided a combustion apparatus capable of accurately determining a combustion abnormality and performing an appropriate abnormality handling process, improving reliability and improving durability and stability. Can be provided.
  According to the third aspect of the present invention, it is possible to provide a hot water supply apparatus that has improved durability and stability while improving reliability.
  Claim4According to the invention described in (1), it is possible to immediately and reliably detect the fire transfer when the combustion amount increases, and it is possible to provide a combustion apparatus with improved reliability.
  Claim5-7According to the invention described in 1), it is possible to provide a combustion apparatus that can prevent the occurrence of gas leakage and can improve durability and reliability.
[Brief description of the drawings]
FIG. 1 is a flow system diagram of a hot water supply apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing an operation principle of a gas mass flow sensor employed in the hot water supply apparatus shown in FIG.
FIG. 3 is a graph showing data contents of a data table stored in the hot water supply apparatus shown in FIG. 1;
4 is a graph showing the relationship between the detection signal of the gas mass flow sensor detected during combustion and the calorific value calculated in the hot water supply apparatus shown in FIG. 1 in comparison with the data table shown in FIG. 3; is there.
FIG. 5 is a graph showing data contents of another data table stored in the hot water supply apparatus shown in FIG. 1;
6 is a graph showing the relationship between the amount of combustion during combustion and the detection signal of the gas mass flow sensor in the hot water supply apparatus shown in FIG. 1 in comparison with the data table shown in FIG. 5;
7 is a graph showing characteristics of a combustion amount and a detection signal of a gas mass flow sensor in a fire transfer state when the combustion amount increases in the hot water supply device shown in FIG. 1;
FIG. 8 is a flowchart showing a combustion abnormality determination control operation in the hot water supply apparatus shown in FIG.
9A and 9B are flow path system diagrams showing a gas leak detection function of the hot water supply apparatus shown in FIG.
FIG. 10 is a graph showing data contents of a data table stored in a hot water supply apparatus according to another embodiment of the present invention.
11 is a graph showing the relationship between the gas secondary pressure during combustion and the gas supply amount in comparison with the data table shown in FIG. 10 in the hot water supply apparatus of another embodiment.
FIG. 12 is a flowchart showing control performed during a trial operation in the hot water supply apparatus of another embodiment.
FIG. 13 is a flowchart showing a combustion abnormality determination control operation in the hot water supply apparatus of another embodiment.
[Explanation of symbols]
1,1 'water heater
2,2 'combustor
9, 9a, 9b Gas burner
13a, 13b ability switching valve
17 Gas proportional control valve
17a Step motor
17b Needle valve
18 Gas mass flow sensor
23 Gas valve
24 Gas pressure sensor (gas secondary pressure sensor)

Claims (7)

A combustion apparatus provided with a gas mass flow sensor for detecting a gas supply amount to a gas burner, wherein a gas supply amount detected by the gas mass flow sensor and a heat amount generated by the combustion apparatus are associated with each combustion amount. Create a data table in advance,
During combustion operation, the gas mass flow sensor sequentially detects the gas supply amount and calculates the amount of heat generated in the combustion device, and with respect to the heat amount stored in the data table corresponding to the detected gas supply amount, A combustion apparatus characterized in that when the amount of heat during combustion operation exceeds a predetermined allowable range, it is determined as a combustion abnormality and a predetermined abnormality handling process is performed.   The combustion apparatus according to claim 1, wherein a data table is prepared in advance in which the gas supply amount detected by the gas mass flow sensor is associated with each combustion amount. When the detected gas supply amount exceeds a predetermined allowable range with respect to the gas supply amount stored in the data table corresponding to the combustion amount, the gas supply amount is A combustion apparatus that performs compensation control so that the gas supply amount stored in the data table corresponds to the combustion amount.   2. A hot water supply apparatus incorporating the combustion apparatus according to claim 1, wherein the amount of heat generated in the combustion apparatus is calculated based on a water supply temperature, a hot water supply temperature, and a water supply amount. A combustion apparatus that has a plurality of gas burners and performs a combustion operation by switching and supplying gas to a predetermined gas burner according to a combustion amount,
For each combustion amount, create in advance a data table that corresponds to the gas supply amount detected by the gas mass flow sensor,
When the combustion amount increases during combustion, the period during which the gas supply amount detected by the gas mass flow sensor exceeds the predetermined range with respect to the gas supply amount stored in the data table corresponding to the increased combustion amount 4. The combustion apparatus according to claim 1, wherein it is determined that the ignition of a part of the burner to which gas supply is performed is incomplete. A combustion apparatus comprising a gas mass flow sensor for detecting a gas supply amount to a gas burner, and a gas on / off valve for controlling opening / closing of gas supply to the gas burner, wherein the gas on / off valve is closed and controlled. The combustion apparatus according to any one of claims 1 to 4 , wherein when a gas supply is detected by a gas mass flow sensor , the gas on / off valve is determined to be a gas leak and a predetermined abnormality handling process is performed. . The combustion apparatus according to claim 5 , comprising a plurality of gas burners, and having a capacity switching valve for supplying gas by switching to each gas burner or each group gas burner according to the combustion amount,
When gas supply is detected by the gas mass flow sensor in a state in which the gas on / off valve is closed and all the capacity switching valves are controlled to open, it is determined that the gas on / off valve has a gas leak,
When gas supply is detected by the gas mass flow sensor in a state in which the gas on / off valve is controlled to open and all the capacity switching valves are closed, any one of the capacity switching valves or the gas mass flow rate is detected. A combustion apparatus characterized in that an abnormality handling process is performed by discriminating gas leakage in a gas flow path downstream of a sensor . The combustion apparatus according to claim 5 or 6 , wherein a gas proportional control valve is provided downstream of the gas on-off valve, and the gas proportional control valve includes a step motor and a needle valve. .

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