JP2020165555A - Combustor - Google Patents

Abstract

To provide a combustor capable of reducing the number of components to determine a state of a circulation path.SOLUTION: A combustor comprises: a circulation pump that forcibly circulates hot water in a bathtub; means of detecting the rotation speed of the circulation pump; a control unit that applies a voltage to the circulation pump so as to have a predetermined rotation speed, and drives the circulation pump; and a water level sensor that detects a water level of hot water in the bathtub. When a pressure detection value of the water level sensor at the time when the circulation pump is driven so that the circulation pump has a predetermined rotation speed by the control unit during reheating operation is within a predetermined range, in the combustor that allows combustion operation, the water level sensor is fixed to the circulation pump.SELECTED DRAWING: Figure 4

Description

The present invention relates to a combustion device having a function of determining whether or not there is hot water in a bathtub.

Combustion equipment that circulates hot water in the bathtub and reheats it is generally a combustion equipment equipped with a water flow switch in the bathtub circulation path.
As an example, this type of conventional combustion equipment includes a combustion unit 5b that heats the water supplied from the water supply pipe connection portion and the hot water in the bathtub, and a circulation pump that forcibly circulates the hot water in the bathtub. 6, a control unit 3 for applying a predetermined voltage to the circulation pump 6 to drive the circulation pump 6, a water flow switch 8 for detecting the circulating water, and a bath return thermista 7 for detecting the return temperature of the circulating water from the bathtub are provided. .. The water flow switch 8 is a sensor that determines the presence or absence of circulating water from the bathtub based on the water flow.

Further, in Patent Document 1, in recent years, for the purpose of making the combustion equipment compact and reducing the number of parts, the water flow switch is omitted and the rotation speed when the DC circulation pump is driven at a constant voltage is equal to or less than the reference value. Also disclosed is a method of detecting a temperature difference before and after a heat exchanger after combustion and determining that hot water in a bathtub is circulated in a certain amount or more when it is within a predetermined range.

Further, in Patent Document 2, a water level sensor that detects the water level of bathtub water is used to determine the amount of circulating water, and by detecting that the water level sensor detection value when the circulation pump is driven is within a predetermined range, the piping is connected. A method for detecting insufficient circulation flow rate (abnormality) due to crushing or blockage is disclosed.

JP-A-2010-156480 Japanese Patent No. 3925569

In the method described in Patent Document 1, the presence or absence of hot water in the bathtub can be accurately detected, but the insufficient circulation flow rate due to the blockage of the pipe cannot be detected before the combustion operation. Therefore, the combustion is performed in the closed state of the pipe and heated. There was a problem of doing it.

On the other hand, in the method described in Patent Document 2, the blockage of the pipe can be detected before the combustion operation, but a connection component for arranging the water level sensor in the pipe and a space for connection are required, and the component. There was a problem that the number of points increased and the piping space was expanded.

The present invention has been made in view of the above-mentioned problems in the conventional method, and can realize compactification of the combustion equipment and reduction of the number of parts, and can determine the presence or absence of hot water in the bathtub and the blocked state of the circulation pipe. It is to provide various combustion equipment.

The present invention has the following configuration as a means for solving the above-mentioned problems.
(1) The present invention includes a combustion unit that heats water supplied from a water supply pipe connection portion and hot water in a bathtub, a circulation pump that forcibly circulates hot water in the bathtub through a circulation path, and rotation of the circulation pump. It is equipped with a means for detecting the number, a control unit that applies a voltage to the circulation pump to drive it at a predetermined rotation speed, and a water level sensor that detects the water level of hot water in the bathtub, and controls when performing reheating operation. When the pressure detection value of the water level sensor when the circulation pump is driven to a predetermined rotation speed by the unit is within a predetermined range, the combustion device permits the combustion operation, and the water level sensor is the said. It is characterized by being fixed to a circulation pump.

(2) The present invention is the combustion apparatus according to the item (1), in which the water level sensor is fixed to the casing of the circulation pump, and the detection unit of the water level sensor is located in the discharge side passage of the circulation pump. It is characterized by being arranged.

(3) The present invention is the combustion apparatus according to the item (1) or (2), and when the change amount of the detection pressure of the water level sensor is detected to be a predetermined value or more, the state of the circulation path is abnormal. The control unit is provided with a function of determining a circulation path abnormality based on a pressure change for determining.

(4) The present invention is the combustion apparatus according to any one of items (1) to (3), and after determining that there is no abnormality in the circulation path and operating, the circulation path is performed during the combustion operation. The temperature difference between the temperature sensor of the circulating water provided on the suction side of the circulation pump and the temperature sensor of the circulating water provided on the downstream side of the reheating heat exchanger on the discharge side of the circulation pump of the circulation path is compared. When the comparison value is equal to or higher than the reference value, the control unit is provided with a function for determining a circulation path abnormality based on a temperature difference for determining the state of the circulation path as an abnormality.

(5) The present invention is the combustion apparatus according to any one of items (1) to (4), and has means for detecting a current flowing when the circulation pump is driven, and the circulation pump of the circulation pump. The control unit is provided with a circulation path abnormality determination function based on a circulation pump current that distinguishes an abnormality state of the circulation path based on the value of the current detected by the means for detecting the current.

According to the present invention, by adopting a structure in which a water level sensor for detecting the water level of the bathtub is attached to a circulation pump for forcibly circulating hot water in the bathtub, it is possible to reduce the number of dedicated parts for arranging the water level sensor, and further, combustion. Since no space for installing dedicated parts is required inside the equipment, it is possible to make the combustion equipment compact and reduce the number of parts.
In particular, by attaching the water level sensor to the casing of the circulation pump, the casing of the circulation pump can be used for attaching the water level sensor, the number of parts for attaching the water level sensor can be reduced, and the installation space for the attachment parts is unnecessary. As a result, the combustion equipment can be made more compact and the number of parts can be reduced. By attaching the water level sensor to the casing of the circulation pump, the water level sensor can be stably attached to the combustion device.

Furthermore, when the state of the circulation path is judged by the water level sensor detection pressure during operation of the circulation pump by attaching the detection unit of the water level sensor to the discharge side passage of the circulation pump casing, compared with the case where it is attached to the suction side of the circulation pump. , The pressure difference between normal and abnormal can be made relatively large, the range of discrimination can be widened, and the detection error due to the variation of the detection pressure of the water level sensor and the fluctuation of the water level can be absorbed, and the accuracy becomes higher. You will be able to make high judgments.
In addition, even when a water level sensor is installed in the circulation path piping on the downstream side of the discharge side of the circulation pump, the detection pressure during operation of the circulation pump can be increased, so that the suction side of the circulation pump A large pressure difference from the case where the pipe is blocked can be secured, and the same effect can be obtained.

In addition, if the circulation path is suddenly blocked during the reheating operation, the reheating combustion can be stopped by the sudden fluctuation of the detection pressure of the water level sensor or the temperature detection of the temperature sensor, so that the pressure in the circulation path piping rises sharply. It can be suppressed.

Furthermore, by detecting the current flowing through the circulation pump during operation of the circulation pump and making a judgment against the reference value, it is possible to distinguish between an abnormality in the circulation path due to blockage and a judgment that there is no water circulating in the bathtub. , It is possible to improve the efficiency of failure diagnosis by distinguishing the failure display.

A schematic diagram showing a configuration and an operating principle of a combustion device according to an embodiment of the present invention is shown. A schematic diagram showing the configuration and operating principle of a combustion device, which is an example of the conventional case, is shown. The operation principle diagram of the circulation pump of the combustion apparatus which is one Embodiment of this invention is shown. The structural drawing of the circulation pump of the combustion apparatus which is one Embodiment of this invention is shown, (a) is a side view of a circulation pump, (b) is a front view, (c) is a plan view of a circulation pump, (d). ) Indicates the mounting state of the thermista, which is a partial cross-sectional view along the AA line of the circulation pump shown in (b), and (e) shows the mounting state of the water level sensor, which is shown in the BB line of the circulation pump shown in (b). A partial cross-sectional view along the line is shown. The flow chart of the operation before combustion of the combustion apparatus which is one Embodiment of this invention is shown. The flow chart of the operation after combustion of the combustion apparatus which is one Embodiment of this invention is shown. A schematic diagram showing the operating principle of the combustion equipment, which is another conventional embodiment, is shown.

FIG. 1 is a schematic diagram illustrating a basic structure and an operating principle of the combustion device 1 of the present invention. Hereinafter, the combustion device 1 according to the present embodiment will be described with reference to FIG. 1 in relation to the flow of hot water, the flow of gas, and the like, in addition to the basic structure.
The combustion device 1 of the present embodiment is roughly configured to include a hot water supply device 4 that performs a hot water supply function and a reheating device 5 that performs a reheating function of bath water.

Further, the reheating device 5 is provided with a reheating combustion unit 5b and a reheating heat exchanger (single heat exchanger) 5a provided on the reheating combustion unit 5b.
The combustion gas that has passed through the reheating heat exchanger 5a passes through the reheating exhaust passage, merges with the combustion gas that has passed through the hot water supply heat exchanger 4a, and is exhausted from the exhaust port.

(Flow of hot water)
First, in the combustion device 1 shown in FIG. 1, the flow of hot water in the reheating device 5 will be described.
The bath return pipe 13b connected to the circulation fitting 15 and the return side pipe 13 are configured from the bath return pipe 13a, and the bath going pipe 14b connected to the circulation fitting 15 and the bath going pipe 14a to the going side pipe 14 are configured. Has been done.
By operating the circulation pump 6 provided inside the combustion equipment main body 1, the hot water in the bathtub 12 is supplied to the bath return pipe connection portion 13c via the circulation metal fitting 15 and the bath return pipe 13b.
The hot water that has passed through the bath return pipe connection portion 13c is guided to the reheating heat exchanger 5a via the bath return pipe 13a, and the sensible heat from the combustion gas is recovered by this reheating heat exchanger 5a. The hot water that has recovered the sensible heat is supplied into the bathtub 12 via the bath going pipe 14a, passing through the bath going pipe connecting portion 14c, and passing through the bath going pipe 14b and the circulation metal fitting 15. The bath going pipe 14a is located on the downstream side of the reheating heat exchanger 5a, and the bath going thermistor (temperature sensor) 16 is incorporated in the bath going pipe 14a so that the temperature of the circulating water can be measured.
In the combustion device 1 shown in FIG. 1, the hot water supply pipe 17 and the bath return pipe 13a in the hot water supply device 4 are connected via the connection pipe 11, and the connection pipe 11 is provided with a hot water injection solenoid valve 10.

(Combustion gas flow)
Next, the flow of fuel gas in the combustion device 1 shown in FIG. 1 will be described.
In the reheating device 5, combustion gas is supplied to the reheating combustion unit 5b via the reheating gas solenoid valve 18 via the connecting pipe 19 and burned, and the generated combustion gas is used in the reheating heat exchanger 5a and It passes through the reheating passage and is exhausted to the outside of the equipment from the exhaust port. In the hot water supply device 4, combustion gas is supplied to the hot water supply device 4 via the connection pipe 19 and burned. The generated combustion gas passes through the hot water supply heat exchanger 4a and the hot water supply passage, is mixed with the combustion gas that has passed through the reheating heat exchanger 5, and is exhausted from the exhaust port to the outside of the appliance.

Next, the arrangement of each sensor in the reheating device will be described with reference to FIGS. 1, 3 and 4.
The bath return thermistor 7 for detecting the temperature of the hot water in the bathtub 12 is generally provided in the bath return pipe 13a between the bathtub 12 and the circulation pump 6 as shown in FIG. 2 in the conventional structure.
However, in the combustion device 1 of this embodiment, a bath return thermistor 7 is provided on the suction side of the circulation pump 6 as shown in FIGS. 1, 4 (b) and 4 (d). In the circulation pump 6, the suction side piping portion 61 and the discharge side piping portion 62 that are mutually communicated with the casing 6A are integrated, and a motor is built in the communication portion between the suction side piping portion 61 and the discharge side piping portion 62. The pump main body 65 is integrated. The outer peripheral portion of the pump main body 65, the outer peripheral portion of the suction side piping portion 61, and the outer peripheral portion of the discharge side piping portion 62 are all integrated as a casing 6A.
As an example, the pump main body 65 is configured to include a drive motor 67 in which a rotary blade 66 is arranged at a communication portion between a suction side piping portion 61 and a discharge side piping portion 62.

As shown in FIG. 4D, the sensor portion 7a of the bath return thermistor 7 has a through hole 6C and an O-ring seal chamber 6D into which a through hole 6C and an O-ring seal chamber 6D can be inserted up to a part of the circulation path in the piping portion 61 on the suction side inside the casing 6A. Along with this, it is provided in the casing 6A of the circulation pump 6. In the circulation pump 6, the inside of the suction side piping portion 61 is a suction side passage 63 forming a part of the hot water circulation path, and the inside of the discharge side piping portion 62 is a discharge forming a part of the hot water circulation path. It is said to be a side passage 64.
A screw hole 6E for fixing the bath return thermistor 7 is provided in the casing 6A so as to be adjacent to the through hole 6C. The holding plate 21 is supported by the bolt 20 screwed into the screw hole 6E, and the bath return thermistor 7 inserted into the through hole 6C of the casing 6A is prevented from coming off by the holding plate 21 and fixed.

Further, as shown in FIG. 4 (e), the water level sensor 9 that detects the water level of the hot water in the bathtub 12 penetrates to the discharge side of the casing 6A of the circulation pump 6 to the circulation path like the bath return thermista 7. It is provided with a hole 6F, an O-ring seal chamber 6G, and fixing screw holes 6H and 6H, and is attached to the circulation pump casing 6A by screw fixing.

Flange portions 9B and 9B are projected on both sides of the main body portion 9A of the water level sensor 9, and bolts 22 penetrating these flange portions 9B are screwed into the screw holes 6H so that the water level sensor 9 can be used as the casing 6A of the circulation pump 6. It is attached to. The tip 9a of the pressure detection unit protruding from the main body 9A of the water level sensor 9 penetrates the through hole 6F and faces the discharge side passage 64 which is a part of the circulation path in the casing 6A.

The structure described above eliminates the need for special parts for arranging the bath return thermistor 7 and the water level sensor 9 in the pipe. That is, the casing 6A of the circulation pump 6 also serves as a part for attaching the bath return thermistor 7 and the water level sensor 9.
In the combustion device 1 of the present embodiment, the bath return thermistor 7 and the water level sensor 9 are arranged in the casing 6A by fixing the screws. However, the bath return thermistor 7 and the water level sensor 9 are provided in a retaining structure using sheet metal parts. Any method may be used for fixing to the casing 6A of the circulation pump 6, and these fixing methods are not limited.

Next, a flowchart of a method for determining the presence of hot water in the bathtub 12 during the reheating operation will be described with reference to FIG. The combustion device 1 shown in FIG. 1 is provided with a remote controller 2 for controlling various functions by the control unit 30, and the functions of the control unit 30 can be controlled by operating the remote controller 2 so that the combustion device 1 can be used. It has become. The control unit 30 has various functions described below in addition to the function of applying a predetermined voltage to the circulation pump 6 to drive the circulation pump 6. As will be described later, the temperature information of the hot water measured by the bath return thermistor 7 and the bath going thermistor 16 is sent to the control unit 30, the pressure information detected by the water level sensor 9 is sent, and the motor of the circulation pump 6 Information such as the number of revolutions is sent.

In step S1 shown in FIG. 5, when the reheating switch arranged on the remote control 2 is pressed by the user, the detection pressure of the water level sensor 9 is first obtained in step S2, and this detection pressure is obtained by the control unit 30 in step S3. It is stored in the storage unit as the pressure Ps when the circulation pump is stopped.
After that, in step S4, a predetermined voltage is applied from the control unit 30 to the circulation pump 6, and the circulation pump 6 is driven.
Subsequently, in step S5, the control unit 30 controls the voltage applied to the circulation pump 6 so that the rotation speed of the motor of the circulation pump 6 becomes the reference rotation speed. If the rotation speed of the circulation pump 6 does not become substantially equal to the reference rotation speed in step S5, the control unit 30 determines that the circulation pump 6 has failed in step S6, stops the circulation pump 6 in step S7, and steps S8. In, the reheating lamp of the remote control 2 is turned off.

When it can be confirmed in step S5 that the rotation speed of the circulation pump 6 has almost reached the reference rotation speed, the pressure is detected by the water level sensor 9 in step S9, and the detected pressure of the water level sensor 9 exceeds the predetermined pressure P1. If so, it is confirmed in step 10 that the detected pressure of the water level sensor 9 is equal to or less than the predetermined pressure P2. If the detected pressure of the water level sensor 9 is equal to or lower than the predetermined pressure P2, it is confirmed in step S11 whether the current flowing through the circulation pump 6 exceeds the predetermined current value I1, and if it exceeds the current value I1, the control unit 30 Starts the reheating operation in step S12. That is, the control unit 30 is provided with a function for determining a circulation path abnormality based on the circulation pump current.

On the other hand, when it is determined in step S9 that the detected pressure of the water level sensor 9 is equal to or less than the predetermined pressure P1 and in step S13 it is determined that the current flowing through the circulation pump 6 is equal to or less than the predetermined current value I1, in step S14. The control unit 30 determines that there is no hot water in the bathtub 12, and the control unit 30 either performs an operation of supplying hot water from the hot water supply path to the bathtub, or stops the reheating operation.
Further, in step S13, when it is determined that the current flowing through the circulation pump 6 exceeds I1, in step S15, the control unit 30 determines that an abnormality has occurred in the return side piping, and stops the reheating operation. That is, the control unit 30 is provided with a function for determining a circulation path abnormality based on the circulation pump current.

Next, a method of determining whether or not a certain amount or more of hot water is circulated during the reheating operation will be described with reference to FIG.
When the reheating switch arranged on the remote control 2 is pressed by the user, first, as described in steps S2 and S3, the detected pressure of the water level sensor 9 is first stored in the storage unit of the control unit 30, and the pressure Ps when the circulation pump is stopped. Remember as.
After that, a predetermined voltage is applied from the control unit 30 to the circulation pump 6, the circulation pump 6 is driven, and the voltage is controlled so that the rotation speed of the circulation pump 6 becomes the reference rotation speed. This is as described above in step S5.

If the piping is in a normal state, the detection pressure Pm of the water level sensor 9 is within the range of the predetermined pressures P1 and P2, and the current flowing through the circulation pump exceeds the predetermined current value I1, first. As described above, according to steps S9, S10, and S11, the control unit 30 determines that a certain amount or more of hot water is circulating, and performs a reheating combustion operation.
The circulation flow rate in the normal piping state of the combustion device 1 is set to about 7 to 9 L / min, and the detection pressure of the water level sensor 9 at that time is about 24 with respect to the pressure Ps when the circulation pump 6 is stopped. It will be doubled.

Here, when the hose is broken or the pipe on the suction side (upstream side) of the circulation pump 6 is blocked by a foreign substance, the detection pressure of the water level sensor 9 decreases with respect to the above-mentioned detection pressure Pm as the circulation flow rate decreases. .. In order to achieve circulation performance and prevent high-temperature hot water flow rate, the detection pressure P1 of the water level sensor 9 assuming a state in which the circulation flow rate drops to 2 to 4 L / min can be used as a threshold value for determination in the case of blockage.
By using this threshold value P1, the determination in step S9 described above can be made. That is, the control unit 30 is provided with a function for determining a circulation path abnormality based on a pressure change.

In the case of the present embodiment, in the combustion device 1, the threshold value P1 is set to be about 10 times the pressure Ps when the circulation pump 6 is stopped, but addition / subtraction (P1 = Ps) with respect to the pressure Ps when the circulation pump 6 is stopped. The threshold value may be the setting of ± α), the addition / subtraction to the detected pressure Pm, or the setting value of multiplication / division.

Next, when the hose is broken or the pipe on the discharge side (downstream side) of the circulation pump 6 is blocked by a foreign substance, the detection pressure of the water level sensor 9 increases with respect to the above-mentioned detection pressure Pm as the circulation flow rate decreases. .. In order to achieve circulation performance and prevent high temperature hot water, the detection pressure P2 of the water level sensor 9 assuming a state in which the circulation flow rate drops to 2 to 4 L / min is used as the threshold value for determination.
By using this threshold value P2, the determination in step S10 described above can be made. That is, the control unit 30 is provided with a function for determining a circulation path abnormality based on a pressure change.
In the combustion device 1, a value about 38 times the pressure Ps when the circulation pump 6 is stopped is set as the threshold detection pressure Ps, but addition / subtraction (P1 = Ps ± α) with respect to the pressure Ps when the circulation pump 6 is stopped. The threshold value may be the setting in the above, addition / subtraction to the detected pressure Pm, or the setting value in multiplication / division.

In step S16, when it is determined that the current flowing through the circulation pump 6 is I1 or more, in step S17, the control unit 30 determines that the circulation pump 6 has failed, and the control unit 30 stops the reheating operation. Further, when it is determined in step S16 that the current flowing through the circulation pump 6 is less than I1, the control unit 30 determines that an abnormality has occurred in the outgoing piping, and the control unit 30 stops the reheating operation.

Next, Ps, Pm, P1 and P2 for each position of the water level sensor 9 are compared.
When the water level sensor 9 is arranged in the piping on the suction side (upstream side) of the circulation pump 6 as in the conventional device shown in FIG. 2, the detected pressure Pm when the circulation pump is driven is a negative pressure of about -20 kPa, and P1 is about. The negative pressure of −35 kPa and P2 are negative pressure of −5 kPa, and the difference between P1 and P2 for determining the normal state is about 30 kPa.
On the other hand, in the combustion device 1 shown in FIG. 1, the detected pressure Pm when the circulation pump is driven becomes a positive pressure of about 48 kPa, P1 becomes a positive pressure of about 20 kPa, and P2 becomes a positive pressure of about 75 kPa, and a normal state is determined. The difference between P1 and P2 is about 55 kPa, which is about 1.8 times or more that of the conventional device (about 30 kPa) shown in FIG. 2 in which the water level sensor 9 is arranged in the suction side (upstream side) pipe. Pressure range can be secured.

That is, in the case where the tip 9a of the pressure detection unit of the water level sensor is attached to the discharge side passage 64 in the casing 6A of the circulation pump 6, the state of the circulation path is determined by the detection pressure of the water level sensor 9 during the operation of the circulation pump 6. Compared with the case where it is attached to the suction side of the circulation pump 6, the pressure difference between the normal state and the abnormal time can be relatively increased, for example, about 1.8 times, and the range of discrimination can be widened. it can. This makes it possible to absorb variations in the detection pressure of the water level sensor 9 and detection errors due to fluctuations in the water level, and to make a more accurate determination.

Next, an abnormality determination flowchart when the pressure Pm at the time of driving the circulation pump 6 is lower than P1 will be described with reference to FIG.
In step S9, when it is determined that the pressure Pm at the time of driving the circulation pump 6 is lower than P1, there is no hot water in the bathtub 12, or the piping on the suction side (upstream side) of the circulation pump 6 has a broken hose or foreign matter. It is assumed that the blockage is caused by.
At this time, if the current value flowing through the circulation pump 6 is determined to be I1 or less in step S13, it is determined that there is no hot water in the bathtub 12 as shown in step S14, and the current value flowing through the circulation pump 6 exceeds I1. In this case, it can be determined that the piping is abnormal (blocked) as shown in step S15.
The control unit 30 can display on the display unit of the remote controller 2 whether there is no hot water in the bathtub 12 or whether there is an abnormality in the piping.

Further, as shown in FIG. 7, when the water level sensor 9 is arranged in the pipe (bath going pipe 14a) on the discharge side (downstream side) of the circulation pump 6, the pressure Pm when the circulation pump 6 is driven is the pipe or heat exchange. Due to the pressure loss of the vessel, the positive pressure is about 25 kPa, P2 is about 15 kPa, P3 is about 70 kPa, and the pressure Pm when the circulation pump 6 is driven and the suction side from the circulation pump 6 ( The difference from P1 for determining the blocked state of the pipe on the upstream side) is about 10 kPa.

On the other hand, in the combustion device 1 having the configuration shown in FIG. 1, the water level sensor 9 is arranged in the discharge side casing 6A of the circulation pump 6, and the detection unit of the water level sensor 9 is positioned on the most upstream side of the discharge side of the circulation pump 6. Therefore, the pressure Pm at the time of driving can be set to the maximum value of the discharge pressure of the circulation pump 6, and the difference from P1 is about 28 kPa, which is about 2.8 times or more a pressure range.
Further, in the combustion device 1 shown in FIG. 1, even if an abnormality such as a blockage occurs in all parts of the piping on the discharge side (downstream side) of the circulation pump 6, it can be detected.

In step S10, when the detected pressure Pm of the water level sensor 9 exceeds a predetermined pressure P2, the current value flowing through the circulation pump 6 is measured in step S16, and when the current value exceeds I1, as shown in step S17. It can be determined that there is an abnormality (blockage) in the piping on the outgoing side. When the current value is I1 or less, it can be determined that the circulation pump 6 has failed as shown in step S18.
The control unit 30 can display on the display unit of the remote controller 2 whether it is a failure of the circulation pump 6 or an abnormality of the outgoing piping.

Next, a flowchart of a determination method when the piping condition becomes abnormal due to hose breakage or blockage due to a foreign object during the reheating operation after determining that the piping condition is normal will be described with reference to FIG.
If a hot water rubber hose is used for the circulation pipe between the bathtub 12 and the combustion device 1, and the hot water rubber hose is sandwiched between the bathtub 12 and the floor, it will not be crushed by cold water, but due to the reheating operation. As the water in the pipe is warmed, the rubber hose may soften and the hose may break.

Assuming such a case, in step S30, it is confirmed in step S30 that the detection pressure of the water level sensor 9 is within a predetermined pressure range (between P1 × 0.95 to P2) even during the reheating operation in the combustion device 1. , If it goes out of range, combustion is stopped. Here, the detection time when determining whether the detection pressure is out of the range is preferably about 2 seconds in order to avoid frequent repetition of reheating combustion ON and OFF.

When it is determined in step S30 that the pressure is within the predetermined pressure range (between P1 × 0.95 to P2), a determination equivalent to the determination made in steps S13, S14, and S15 described above based on FIG. 5 is made. , A judgment equivalent to the judgment made in steps S10, S16, S17, S18 is made. If it is determined that the piping is abnormal in steps S15 and S18, the reheating operation is stopped as shown in step S40.

However, in rare cases, if combustion is stopped after the detection time due to a sudden break in the hose, a sudden rise in pressure in the pipe cannot be suppressed, and there is a possibility that the hose may come off. Therefore, in the combustion equipment 1, when a sudden drop in the detection pressure of the water level sensor 9 is detected in response to a sudden hose break, it is determined that the return side piping is abnormal in step S, or step S. When a sudden rise in the detection pressure of the water level sensor 9 is detected as shown in S32, it is determined in step S34 that the piping on the outgoing side is abnormal, and combustion is immediately stopped as shown in step 31. Specifically, when it fluctuates by 10 kPa or more within about 0.5 seconds, combustion is stopped immediately.

Further, in the combustion device 1 of the present embodiment, a function of determining an abnormality in the piping is added based on the detection temperature of the thermistor arranged in the circulation path in consideration of the failure of the water level sensor and the like.
If the circulation flow rate drops below a certain amount due to hose breakage or blockage due to foreign matter during the reheating operation, the reheating heat exchange with the bath return thermistor 7 provided upstream from the reheating heat exchanger 5a in the circulation path. It is detected that the temperature difference from the bath going thermistor 16 provided on the downstream side of the vessel 5a rises above the reference value, and the combustion is stopped immediately.

When the temperature difference between the detection temperature of the bath going thermistor 16 and the detection temperature of the bath returning thermistor 7 exceeds the reference value as shown in step S35, it is determined in step S36 that the piping is abnormal and the reheating operation is performed as shown in step S40. To cancel.
Further, as shown in step S37, when the temperature difference between the detection temperature of the bath going thermistor 16 and the detection temperature of the bath returning thermistor 7 is less than the reference value, it is determined in step S38 that the return side piping is abnormal and the temperature difference is shown in step S40. Stop the reheating operation.
That is, the control unit 30 is provided with a function for determining a circulation path abnormality based on the temperature difference.

The temperature difference is applied by calculating the temperature difference when the circulation flow rate is lower than 2 to 4 L / min with respect to the reheating combustion amount.
Further, when the piping on the discharge side (downstream side) of the circulation pump 6 is suddenly and completely blocked, it is assumed that the hot water heated by the reheating heat exchanger 5a flows backward, and the bath return thermistor 7 is used. Even when the detected temperature becomes higher than the reference value of the bath going thermistor 16, it is determined in step S39, combustion is immediately stopped as shown in step S40, and the circulation pump 6 is stopped. As a result, it is possible to obtain a combustion device 1 having higher safety for a pipe blockage abnormality during reheating combustion.

Although various embodiments of the present invention have been described above, the configurations and combinations thereof in each embodiment are examples, and the configurations are added, omitted, replaced, and the configurations are added, omitted, replaced, and the like without departing from the spirit of the present invention. Other changes are possible. Further, the present invention is not limited to the embodiments.

1 ... Combustion equipment, 2 ... Remote control, 3 ... Control unit, 4 ... Hot water supply device, 4a ... Hot water supply heat exchanger,
4b ... Hot water supply combustion unit (combustion unit), 5 ... Reheating device, 5a ... Reheating heat exchanger,
5b ... Reheating combustion part (combustion part),
6 ... Circulation pump, 6A ... Casing, 7 ... Bath return thermistor (temperature sensor), 7a ... Sensor unit,
8 ... Water flow switch, 9 ... Water level sensor, 9A ... Main body, 9a ... Tip,
10 ... Hot water pouring solenoid valve, 11 ... Connection piping, 12 ... Bathtub, 13a, 13b ... Bath return piping,
14a, 14b ... Bath going piping, 15 ... Circulation fittings, 16 ... Bath going thermistor (temperature sensor),
18 ... Reheating gas solenoid valve, 19 ... Connection piping, 30 ... Control unit,
61 ... Suction side piping section, 62 ... Discharge side piping section, 63 ... Suction side passage, 64 ... Discharge side passage, 65 ... Pump body section.

Claims (5)

A combustion unit that heats the water supplied from the water supply pipe connection portion and the hot water in the bathtub, a circulation pump that forcibly circulates the hot water in the bathtub through a circulation path, and a means for detecting the rotation speed of the circulation pump. A control unit that applies a voltage to the circulation pump to drive it at a predetermined rotation speed and a water level sensor that detects the water level of hot water in the bathtub are provided, and the control unit determines the circulation pump during the reheating operation. When the pressure detection value of the water level sensor when the circulation pump is driven so as to reach the rotation speed of is within a predetermined range, it is a combustion device that permits combustion operation, and the water level sensor is fixed to the circulation pump. A combustion device characterized by being present. The combustion apparatus according to claim 1, wherein the water level sensor is fixed to the casing of the circulation pump, and the detection unit of the water level sensor is arranged in the discharge side passage of the circulation pump. When the amount of change in the detection pressure of the water level sensor is detected to be a predetermined value or more, the control unit is provided with a function of determining a circulation path abnormality based on the pressure change for determining the state of the circulation path as an abnormality. The combustion apparatus according to claim 1 or 2. After determining that there is no abnormality in the circulation path and operating, during the combustion operation, the temperature sensor of the circulating water provided on the suction side of the circulation pump of the circulation path and the reheating heat exchanger on the discharge side of the circulation pump of the circulation path. A function for determining a circulation path abnormality based on the temperature difference that compares the temperature difference with the temperature sensor of the circulating water provided on the downstream side and determines that the state of the circulation path is abnormal when the comparison value is equal to or higher than the reference value. The combustion apparatus according to any one of claims 1 to 3, wherein the control unit is provided. It has a means for detecting the current flowing when the circulation pump is driven, and distinguishes the abnormal state of the circulation path by the value of the current detected by the means for detecting the current of the circulation pump. The combustion apparatus according to any one of claims 1 to 4, wherein the control unit is provided with the determination function of the above.

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