JP4110665B2 - Combustion improvement method for combined combustion equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a composite combustion apparatus in which a bath recuperation heat exchange circuit or a heating heat exchange circuit is combined with a hot water supply heat exchange circuit, such as a water heater with a water heater or a heater with a water heater, for example. The present invention relates to a combustion improvement method used for improving combustion when a circuit is operated simultaneously.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as this type of combined combustion equipment, a combination of a hot water supply heat exchange circuit and a heating heat exchange circuit is known (see, for example, JP-A-10-122579). In this apparatus, a blower fan, a combustion burner, and a heat exchanger are individually provided in each of the hot water supply heat exchange circuit and the heating heat exchange circuit, and the combustion exhaust from each heat exchange circuit is externally passed through individual exhaust pipes. Has been exhausted. Further, in a combined combustion device that combines a hot water supply heat exchange circuit and a bath heat exchange circuit, combustion exhaust from each is exhausted through the same exhaust pipe, and a CO sensor is provided in the common exhaust pipe. A thing is also known (for example, refer to Japanese Patent Publication No. 4-38973). This system compensates for changes in the characteristics of the CO sensor in accordance with changes in the temperature of the combustion exhaust to which the CO sensor is exposed, so that the incomplete combustion state can be detected correctly, and both combustions occur due to the occurrence of the incomplete combustion state. The fuel supply to the vessel is stopped.
[0003]
Also, in the above hot water supply heat exchange circuit, usually, combustion operation control by a combination of feedforward control (hereinafter referred to as “FF control”) based on the target hot water discharge capacity and follow-up correction by feedback control (hereinafter referred to as “FB control”). On the other hand, in the heating or regenerative heat exchange circuit, the combustion operation characteristics for the combustion of each combustor are greatly different such that the combustion operation control is performed by switching to one stage or a plurality of stages by a fixed value. .
[0004]
[Problems to be solved by the invention]
By the way, in each of the heat exchange circuits described above, in addition to incomplete combustion mainly due to long-term aging such as clogging of heat-absorbing fins of the heat exchanger, outdoor wind from the exhaust pipe side of the combustion exhaust enters the combustion chamber. Incomplete combustion (combustion abnormality) may occur due to temporary (continuous in a certain time range) disturbance such as reverse flow. Such an incomplete combustion state due to a temporary disturbance is greatly different in the combustion operation control in both heat exchange circuits for hot water supply and other reheating, as described above. Depending on the operation, it may occur only in one heat exchange circuit and not in both heat exchange circuits.
[0005]
However, in the combined combustion apparatus configured such that the combustion exhaust from the two heat exchange circuits as described above is discharged from a common exhaust pipe, when the two heat exchange circuits are simultaneously operated by combustion, The combustion exhaust from each combustor of both heat exchange circuits is discharged in a mixed state. For this reason, even if a CO sensor is provided in the common exhaust stack and the occurrence of an incomplete combustion state is known due to an increase in CO concentration, which side of the combustor is generating the incomplete combustion state. This is difficult or impossible.
[0006]
For this reason, in the combined combustion equipment in the simultaneous combustion operation state, even if a combustion abnormality (incomplete combustion) occurs in the heat exchange circuit on one side due to the temporary disturbance as described above, it is not possible to improve the combustion. It becomes difficult. On the other hand, if both the heat exchange circuits during simultaneous combustion operation are uniformly stopped by detecting the occurrence of an incomplete combustion state due to an increase in CO concentration, this will cause confusion and inconvenience for the user. . Further, if both the heat exchange circuits are uniformly improved in combustion, there is a risk of deteriorating the combustion state on the side where normal combustion is performed.
[0007]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a combustion abnormality during simultaneous combustion operation in a composite combustion device that collects and exhausts combustion exhaust from each heat exchange circuit. It is an object of the present invention to provide a combustion improvement method capable of accurately identifying a combustion apparatus in which a combustion abnormality has occurred even if this occurs, thereby performing appropriate combustion improvement.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, a combustor in which fuel is supplied so that the supply amount can be changed, a blower that supplies combustion air to the combustor so that the supply amount can be changed, and a combustor from the combustor. The first and second heat exchange circuits each having a heat exchanger that absorbs combustion heat and heats the introduced medium to be heated are provided, and the combustion exhaust from both heat exchange circuits is collected and exhausted. A combustion improvement method for a composite combustion device in which an exhaust component detection means for detecting a concentration of a specific component in combustion exhaust that fluctuates due to a combustion abnormality of the combustor
When the detected concentration from the exhaust component detection means exceeds a preset determination value in a state where the combustion operation in both the first and second heat exchange circuits is being performed alone, the first and second A combustion improvement step for improving the combustion state by correcting by increasing or decreasing the rotation speed of one of the blowers to the combustion improvement side,
A counter unit that counts and stores the number of times the combustion improvement step has been performed is provided, and when the count number of the counter unit exceeds a preset setting value, in the subsequent combustion operation, the corresponding blower A constant improvement step for constantly correcting the rotational speed from the initial stage of combustion;
When both the first and second heat exchange circuits are in a simultaneous combustion operation state, and the detected concentration from the exhaust component detection means exceeds a predetermined determination value, the first and second counter units , The combustion state on the side with the larger count number is determined to be abnormal, and the combustion state is improved by correcting by changing the rotational speed of the blower on the side determined to be abnormal combustion to the combustion improvement side And a simultaneous combustion improving step.
Further, as a second feature of the present invention, in addition to the method for improving the combustion of the composite combustor shown in the first feature, no combustion abnormality is detected in single combustion or simultaneous combustion, and a normal combustion state is previously detected. In the case where the process is performed continuously for a predetermined time or more, the count number of the counter unit may be reduced.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be specifically described with reference to the drawings.
FIG. 1 is a schematic view of a composite combustion device to which a combustion improvement method according to an embodiment of the present invention is applied. First, the basic structure and basic control of this composite combustion device will be described.
[0010]
This combined combustion apparatus is a combination of a hot water supply heat exchange circuit 101 and a bath heat exchanger circuit 201, and uses water or hot water as a heating medium.
[0011]
The hot water supply heat exchange circuit 101 heats the water introduced into the hot water supply side heat exchanger 22 from the water supply pipe 21 connected to a general household water pipe by the combustion heat of the hot water supply side combustion burner 23 as a combustor, The heated hot water is discharged to the downstream hot-water tap 25 through the hot water supply pipe 24. A bypass pipe 26 that bypasses the hot water supply side heat exchanger 22 is communicated with the water supply pipe 21 and the tapping pipe 24, respectively, and the opening degree control of the water amount adjusting valve 27 that is interposed in the bypass pipe 26 is performed. Thus, the temperature of hot water discharged from the hot water tap 25 is adjusted by flowing water into the hot water from the heat exchanger 22.
[0012]
The water supply pipe 21 on the heat exchanger 22 side (downstream side) with respect to the branch position of the bypass pipe 26 has an incoming water amount sensor 28 for detecting a flow rate flowing into the heat exchanger 22, and water flowing in An incoming water temperature sensor 29 for detecting the temperature is provided. On the other hand, a tapping temperature sensor 30 for detecting the temperature of the hot water discharged from the heat exchanger 22 is disposed in the tapping pipe 24 on the heat exchanger 22 side (upstream side) depending on the joining position of the bypass pipe 26. Yes. In addition, a water amount adjusting valve 31 and a hot water supply temperature sensor 32 for detecting a temperature of hot water supplied to the hot water tap 25 or a bath pouring pipe 41 described later are provided in the hot water supply pipe 24 downstream of the joining position. Is arranged.
[0013]
The reheating heat exchange circuit 201 combusts the reheating side combustion burner 37 using the hot water in the bath 36 returned to the reheating heat exchanger 35 by the suction operation of the circulation pump 34 from the return line 33 as a combustor. Further heating is performed by heat, and the heated hot water is returned to the bathtub 36 through the forward pipe 38 and circulated and chased. The return pipe 33 on the discharge side (downstream side) of the pump 34 is provided with a water flow switch 39 and a bath water temperature sensor 40 that detects the temperature of the hot water flowing into the tracking side heat exchanger 35. ing.
[0014]
The hot water pouring into the bathtub 36 is branched from the downstream side of the outlet hot water pipe 24 and communicates with the return pipe 33 at the discharge side of the pump 34 through the hot water hot water pipe 46 and the hot water supply heat exchange circuit 101. Hot water from is supplied. The bath pouring pipe 41 is poured into the bathtub 36 and a solenoid valve 43 for pouring the hot water by opening / closing control from the branching position with the outlet hot water pipe 24 to the joining position with the return pipe 33. A pouring amount sensor 42 for detecting the flow rate of hot water and two-stage check valves 44 and 45 for preventing the bath 36 side hot water from mixing into the hot water supply side are sequentially arranged.
[0015]
Each of the temperature sensors 29, 30, 32, and 40 may be formed of, for example, a thermistor, and the incoming water amount sensor 28 or the poured water amount sensor 42 is rotated by, for example, the flow of water or hot water in the pipe. What is necessary is just to comprise so that a flow volume may be detected by the rotation speed detection of an impeller.
[0016]
In the hot water supply heat exchange circuit 101, the heat exchanger 22 with the heat absorption fins 221 is disposed at the upper part of the combustion chamber 48 in the independent hot water supply side casing 47, and a combustion burner 23 as a combustor is provided at the lower part of the combustion chamber 48. It is arranged. The lower end portion of the hot water supply side casing 47 communicates with the blower cylinder 74a of the hot water supply side blower fan 74 as a blower so that the air blown by the rotational drive of the fan motor 75 is supplied to the combustion chamber 48 as combustion air. It has become.
[0017]
In the additional heat exchanging circuit 201, the heat exchanger 35 with the heat absorption fins 351 is also disposed at the upper part of the combustion chamber 50 in the independent additional casing 49, and a combustion burner as a combustor is disposed below the combustion chamber 50. 37 is disposed. A fan cylinder 77a of a fan side fan 77 as a blower communicates with the lower end portion of the tank side casing 49, and the air blown by the rotational drive of the fan motor 78 is supplied to the combustion chamber 50 as combustion air. It has become so.
[0018]
The hot water supply side fan motor 75 is provided with a rotation speed sensor 76 for detecting the rotation speed, and the tracking fan motor 77 is provided with a similar rotation speed sensor 79.
[0019]
Further, the upper ends of the two casings 47 and 49 on the hot water supply side and the retreat side are gathered together to form a collective exhaust pipe 72. The collective exhaust pipe 72 is assembled from both the hot water supply side and the retreat side. A CO sensor 71 is provided as exhaust component detection means for detecting the concentration of CO as a specific component in the combustion exhaust.
[0020]
A fuel supply pipe 55 is branched and connected to both the hot water supply side and the combustion side combustion burners 23 and 37, and a fuel solenoid valve 56 as a main plug is connected to the fuel supply pipe 55 in order from the fuel source side, An electromagnetic proportional valve 57 for adjusting the fuel supply amount is provided. In addition, at the downstream end of the hot water supply side branch pipe of the fuel supply pipe 55, a plurality (three in the example) of selectively increasing the heating capacity by selectively switching the fuel supply to the hot water supply side combustion burner 23. The solenoid valves 59, 60, 61 are provided. In addition, an electromagnetic valve 58 for opening / closing the fuel supply from the upstream side, a governor 58b for pressure adjustment, and a tracking side branch pipe branched from an intermediate position between the electromagnetic valve 56 and the electromagnetic proportional valve 57 of the fuel supply pipe 55, An electromagnetic valve 58a for switching the combustion capacity is provided.
[0021]
In FIG. 1, 62 is an ignition transformer, 63 and 64 are ignition plugs for igniting combustion burners, and 65 and 66 are flame rods for confirming ignition.
[0022]
In the combined combustion apparatus having the above basic structure, each operation of hot water supply, pouring and reheating is controlled based on outputs from the above-mentioned various sensors by a controller 301 configured by an MPU and a memory. It has become. The controller 301 is configured to control each operation as described above by issuing an operation command to each solenoid valve or the like according to a predetermined control program written in a memory or the like. Hereinafter, basic operation control for these driving operations will be described.
[0023]
The hot-water supply operation control of the hot-water supply heat exchange circuit 101 is performed by a user operating the hot water switch of a remote controller (hereinafter referred to as “remote controller”) 80 to ON and opening the hot-water tap 25 so that the incoming water amount sensor 28 is a predetermined minimum operation. It starts by detecting a flow rate above the amount of water. First, the number of hot water numbers (target number) necessary to realize the hot water supply temperature set in the remote controller 80 is calculated. Then, each FF control amount is calculated for a target fuel supply amount that realizes the calculated target number and a target air supply amount that becomes a predetermined air-fuel ratio with respect to this target fuel supply amount, and based on each FF control amount The rotational speeds of the various proportional solenoid valves 57 and 59 to 61 of the fuel supply pipe 55 and the fan motor 75 of the blower fan 74 are FF controlled. Next, after the hot water supply side combustion burner 23 is burned, the actual number of hot water discharged (actual number) is calculated based on the detected values from the incoming water amount sensor 28, the incoming water temperature sensor 29, and the outgoing hot water temperature sensor 30, and the target number is calculated. The target fuel supply amount is sequentially corrected by the FB control so that the number difference (FB control amount) between the number and the actual number becomes zero.
[0024]
On the other hand, the chasing operation control of the chasing heat exchanging circuit 201 is started when the chasing switch of the remote controller 80 is turned on, so that the combustion amount at the combustion stage corresponding to the boiling temperature set in the remote controller 80 is obtained. Stepwise switching control is performed. That is, the combination of the fuel supply amount and the blast amount is set in advance according to the combustion amount in a plurality of stages, and the various solenoid valves 56, 58, 58a and the fan motor 78 are switched and controlled so that the combustion amount in the predetermined stage is obtained. It has come to be. When the detected hot water temperature from the bath water temperature sensor 40 reaches the boiling temperature, the combustion by the combustion burner 37 is stopped.
[0025]
When the hot water supply heat exchanging circuit 101 and the additional heat exchanging circuit 201 are operated simultaneously, the hot water supply operation control and the additional operation control are controlled independently of each other.
[0026]
A combustion improvement method according to the present invention will be described with reference to a flowchart.
FIG. 2 is a flowchart showing a combustion improvement control method during single operation according to the present invention. Here, a single operation of hot water supply will be described as an example of the single operation.
[0027]
First, as described above, when an instruction to start a hot water supply operation is given (step S0), combustion in the hot water supply heat exchanger circuit 101 is started (step S1). Here, it is compared whether or not the hot water combustion improvement number Q is greater than a predetermined reference number Qk, and if Q is equal to or greater than Qk (YES in step S2), a constant combustion abnormality (heat absorption fin of the heat exchanger). The combustion operation is performed with the rotational speed of the hot water supply fan corrected (step S3), and then the process proceeds to step S4. If Q is Qk or less (NO in step S2), the process proceeds to step S4 with no abnormality.
[0028]
In step S4, the CO concentration detected by the CO sensor 71 is compared with the reference value X, and if the CO concentration is X or more (YES in step S4), the process proceeds to step S6, and the product of the CO concentration and time is integrated. . This is to eliminate the influence of temporary disturbances (for example, gusts). If the CO concentration does not exceed the reference value X (NO in step S4), the process proceeds to step S5, and if there is a CO integrated value, the integrated value is reset, and the process returns to step S4.
[0029]
If the integrated value exceeds the integrated reference value Y in step S7 (YES in step S7), it is determined that a combustion abnormality has occurred, and the combustion state is normalized by increasing the rotation speed of the hot water supply blower. (Step S8). When the rotation speed is corrected, the hot water supply combustion improvement count Q is increased by 1 (step S9), the process returns to step S4, and the combustion is continued.
[0030]
Next, processing when hot water supply is stopped will be described. When the hot water supply operation is stopped by closing the hot water tap 25 in step S10, combustion in the hot water supply heat exchange circuit 101 stops (step S11). In step S12, it is determined whether or not the rotation speed correction of the hot water supply blower has been performed during this hot water supply operation. If there is a correction (YES in step S12), the process proceeds to step S15 and enters a standby state for the hot water supply operation. If there is no correction (NO in step S12), the process proceeds to step S13, and the current hot water supply operation time is compared with the reference operation time t. If the combustion time is equal to or shorter than the reference operation time t (NO in step S13), the process proceeds to step S15. If the combustion time is equal to or longer than the reference operation time t (YES in step S13), it is determined that the normal combustion state is continued for a certain amount of time or more, and therefore a constant abnormal combustion state occurs. If not, the hot water combustion improvement count Q is decreased by 1 (step S14), and the process proceeds to step S15. Here, Q is assumed not to be 0 or less.
[0031]
FIG. 3 is a flowchart showing a combustion improvement control method during simultaneous operation according to the present invention. Here, the situation where the bath memorial operation is started during the hot water supply operation will be described. When a bath retreat command is issued during hot water supply combustion (step S20), combustion of the recuperation heat exchange circuit 201 is started in step S21, and a simultaneous combustion operation state is entered.
[0032]
Here, it is compared whether the number of memorial combustion improvements F is greater than a predetermined reference number Fk. If F is greater than or equal to Fk (YES in step S22), a permanent combustion abnormality (heat absorption of the heat exchanger). The combustion operation is performed in a state where the rotational speed of the bath blower is corrected by determining that the exhaust blockage due to clogging of the fins and the like is caused (step S23), and then proceeds to step S24. If F is equal to or less than Fk (NO in step S22), the process proceeds to step S24 with no abnormality. At this time, the hot water supply side continues the state before the simultaneous operation shift, and if there is a rotation speed correction of the hot water supply blower before the simultaneous operation shift, the correction state is continued even during the simultaneous operation.
[0033]
In step S24, the CO concentration detected by the CO sensor 71 is compared with the reference value Xd. If the CO concentration is equal to or greater than Xd (YES in step S24), the process proceeds to step S26, and the product of the CO concentration and time is integrated. . If the CO concentration does not exceed the reference value Xd (NO in step S24), the process proceeds to step S25, and if there is a CO integrated value, the integrated value is reset, and the process returns to step S24.
[0034]
If the integrated value exceeds the integrated reference value Yd in step S27 (YES in step S27), it is determined that a combustion abnormality has occurred and the combustion state is improved. At this time, the hot water supply combustion improvement frequency Q is compared with the additional combustion improvement frequency F in step S28, and if Q is equal to or greater than F (YES in step S28), there is a high possibility that the hot water combustion is in a combustion abnormality. In step S29, the rotational speed of the hot water supply side blower is corrected. If Q is less than F (NO in step S28), the rotational speed of the bath side blower is corrected in step S30. Combustion is continued (step S31).
[0035]
The above shows one preferred embodiment of the present invention, but the present invention is not limited to this. For example, in step S28, the hot water combustion improvement number Q and the supplementary combustion improvement number F are simply compared, but the comparison is made with the combustion improvement rate in consideration of the total operation time or the number of operations of the hot water supply operation and the supplementary combustion operation. You can also. In this embodiment, the number of times of improvement in combustion is increased or decreased by a constant, but this can also be handled in an analog manner depending on the magnitude of the CO integrated value and the length of normal combustion time.
【The invention's effect】
The present invention has the above-described configuration and operation. In the method for improving combustion of a composite combustion device according to claim 1, the number of times of combustion improvement at the time of single combustion in each heat exchange circuit is counted, and the total number of times is predetermined. When it reaches a certain number of times, it is judged that the combustion state in the heat exchange circuit is constantly deteriorated, and the rotational speed of the combustion blower is corrected immediately after the start of the combustion. A good combustion state can be maintained. In addition, when combustion failure is detected by the exhaust component detection means during simultaneous combustion, it is possible to identify the heat exchange circuit in a combustion failure state by comparing the number of times of improvement in combustion in each heat exchange circuit Therefore, the combustion state at the time of simultaneous combustion can be improved without performing unnecessary combustion correction. According to the combustion improvement method of the second aspect, when the normal combustion state is continuously performed for a predetermined time or more, a control method for reducing the count number of the combustion improvement times is performed. Adopted. This is because, for example, in the case of an appliance installed in a situation where a continuous strong wind is expected (such as a veranda in a high-rise apartment building), the deterioration of the combustion state is caused by factors other than the malfunction of the appliance body. However, if the number of times of improvement in combustion is increased unilaterally, even if there is no malfunction in the instrument, a misjudgment is made in which it is constantly determined that the combustion is defective. The control according to claim 2 makes it possible to prevent such erroneous determination and accurately detect the deterioration state of the combustion state.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a composite combustor according to the present invention.
FIG. 2 is a flowchart showing a combustion improvement method during single combustion in the present invention.
FIG. 3 is a flowchart showing a combustion improvement method during simultaneous combustion in the present invention.
[Explanation of symbols]
23, 37 Combustion burner (combustor)
74,77 Blower (blower)
71 CO sensor (exhaust component detection means)
72 Collective exhaust pipe (part where combustion exhaust is collected and discharged)
101 Hot Water Heat Exchange Circuit 201 Remembrance Heat Exchange Circuit

Claims (2)

A combustor in which fuel can be supplied in a variable amount, a blower that supplies combustion air to the combustor in a variable amount of supply, and a heated medium introduced by absorbing the heat of combustion from the combustor. The first and second heat exchange circuits each having a heat exchanger to be heated are provided, and the combustion exhaust from both the heat exchange circuits gathers and is exhausted by the combustion abnormality of the combustor. A combustion improvement method for a composite combustion device provided with exhaust component detection means for detecting the concentration of a specific component in combustion exhaust,
When the detected concentration from the exhaust component detection means exceeds a preset determination value in a state where the combustion operation in both the first and second heat exchange circuits is being performed alone, the first and second A combustion improvement step for improving the combustion state by correcting by increasing or decreasing the rotation speed of one of the blowers to the combustion improvement side,
A counter unit that counts and stores the number of times the combustion improvement step has been performed is provided, and when the count number of the counter unit exceeds a preset setting value, in the subsequent combustion operation, the corresponding blower A constant improvement step for constantly correcting the rotational speed from the initial stage of combustion;
When both the first and second heat exchange circuits are in the simultaneous combustion operation state, when the detected concentration from the exhaust component detection means exceeds a preset determination value, the first and second counter units are turned on. In comparison, it is determined that the combustion state on the side with the larger count number is abnormal, and the combustion state is improved by correcting by changing the rotational speed of the blower on the side determined to be abnormal combustion to the combustion improvement side. And a simultaneous combustion improving step. A method for improving the combustion of a composite combustion device. The method for improving combustion of a composite combustor according to claim 1,
In the single combustion or simultaneous combustion, when the combustion abnormality is not detected and the normal combustion state is continuously performed for a predetermined time or more, the count number according to claim 1 is reduced. Combustion improvement method for combined combustion equipment.

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