JPS6069429A - Combustion control device for water heater - Google Patents

Abstract

PURPOSE:To provide a combustion control device for a water heater capable of acting as a convinient water heater in its use by a method wherein a diagnosis for trouble can be performed for a water flow sensor. CONSTITUTION:A combustion control device is provided with a water flow sensor 31 for sensing a water flow of a heat exchanger 23, a water volume sensor 30 for sensing an incoming water volume for the heat exchanger 23, a sensor means for turning on or off the water flow sensor 31, a reading means for reading the sensed value of the water flow volume sensor means 30 in case of turned-on or off condition of the water flow sensor 31 in response to the operation of the sensor means, and a discriminating means for discriminating whether the turned-on level or turned-off level of the water flow sensor 31 is normal or not. When the actual turned-on level or turned-off level of the water flow rato sensor 31 is displaced from the normal turned-on level or turned-off level, this condition is immediately detected. With this arrangement, it is possible to know a replacement time of the water flow rate sensor 31 before the water heater shows an abnormal condition.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a combustion control device for a water heater, and particularly to one equipped with a fault diagnosis function for a water flow detector.

(For the blue version of the invention) The heat exchanger's flow rate is a highlight! The amount of combustion is controlled by various control methods such as feedback control so that the temperature is the same, and the ignition operation of the burner and the combustion stop operation are controlled by the generation and disappearance of water flow in the heat exchanger. .

In other words, the water flow detector installed on the water inlet side of the heat exchanger turns on at IeK@small inflow water Φ required for hot water temperature control.
It also turns off when the water flow disappears.

This type of water flow detector is constructed, for example, as shown in FIG. In the figure, a housing 1 of the water flow detector is provided with a flow path 2 for water flowing in the direction of the arrow shown in the figure, and a holder 4 protrudes from a WI 3 installed above the flow path 2. It is set up. The holder 4 has an actuating plate 5, one end of which is rotatably supported by the bottle 6, and the other end of which is provided with a step (
). A magnet 7 is attached to the surface in the direction in which the actuating plate 5 is rotated by the water flow passing in the direction of the arrow shown in the figure (=J
-1), and a reed switch 8 driven by the magnet 7 is installed in the housing 1.The actuating plate 5 is connected to a bar (not shown) wound around the bottle 6. −=
It is biased in the opposite direction to the rotation direction p.

With such a configuration, when water flows through the flow path 2 in the direction of the arrow shown in the figure, the actuating plate 5 is biased by this and rotates to the receiving state as shown by the solid line in the figure. In the process of rotating to the state not shown by the solid line, the reed switch 8 is turned on by the magnet 7. That is, the reed switch 8 is turned on from the minimum amount of inflow water required for hot water temperature control to the maximum amount of inflow water m required for hot water control in the water heater. When the water flow in the channel 2 disappears, the actuating plate 5 is urged forward by the spring force and changes from the state shown by the solid line to the state shown by the broken line.

During this changing process, the reed switch 8 is turned on. - However, as is well known, when this type of water flow detector is used for a long period of time, the Q2.
There is so-called limescale on the H side, which changes the on level and off level of the reed switch 8. In other words, the reed switch 8 will not turn on unless the amount of water is larger than the minimum inflow water level required for hot water temperature control, and if there is a change to reduce the hot water output m, the reed switch 8 will turn on.
This causes the water heater to malfunction, resulting in a water heater that is extremely difficult to use.

(Object of the Invention) An object of the present invention is to provide a combustion control device for a water heater that can provide an easy-to-use water heater by enabling failure diagnosis of a water flow detector. It is in.

(Structure and Effects of the Invention) In order to achieve the above object, the combustion control device for a water heater according to the present invention includes a water flow detector that detects the water flow of the heat exchanger, and a water flow detector that detects the water flow m of the heat exchanger. a water flow detector for detecting water flow; a detection means for detecting on/off operation of the water flow detector;
reading means for reading the detected value of the water amount detector when it is off;
The apparatus is characterized by comprising a determining means for determining whether or not the on-level and off-level of the water flow detector are normal based on the reading value of the reading means.

According to this configuration, if the actual on/off level of the water flow detector deviates from the normal on/off level, this will be detected sloppily, and the water heater will be detected before it reaches normal operation. In addition, +i11 can be known at the time of replacing the water flow detector.

(Description of Embodiments) FIG. 2 is a diagram without showing the basic configuration of a water heater equipped with a combustion control device according to an embodiment of the present invention.

In the figure, a water heater body 21 is formed into a vertical cylindrical shape, and a burner 22 is disposed at the bottom thereof, and a heat exchanger 23 is disposed at the top thereof. In J5, a livery fan (not shown) is installed at the upper exhaust port of the heat exchanger 23.

The gas supply line to the barb 22 is supplied with gas.
Solenoid switching valve 24. A governor 25 and a gas flow rate regulating valve 26 are arranged in this order. In association with the barb 22, there are provided an igniter 27 that generates a J11 spark, and a flame detector 28 that detects whether or not the ignition operation ignites the fire secantly.

%h it M, IXl fishing lure mouth 11111
Jubayashi k I to the meeting! 1-11. ui 1llll m valve 29. Water H) Detector 30. A water flow detector 31 and an incoming water temperature detector 32 are arranged in this order.

A temperature detector 33 is installed in the hot water supply pipe on the outlet side of the heat exchanger 23.
is provided and a plurality of bells are attached.

The electromagnetic switching valve 24 has two states, a fully open state and a fully open state, and is controlled to open and close by a signal from the controller 1-roller 34.

The governor 25 has a machine O18 that mixes fuel gas and air in an appropriate ratio.

The gas flow rate adjustment valve 26 is composed of, for example, a motor-driven servo valve whose opening degree can be continuously adjusted from a fully open state to a fully open state. Controller 3 via potentiometer etc.
Sent to the 4th side.

The igniter 27 activates the burner 2 according to a command from the controller 34.
Perform the ignition operation for 2.

The flame detector 28 converts the flame into an electrical signal by using the rectification effect of the flame emitted from the burner 22, amplifies this as appropriate, smooths it with a fixed circuit having a relatively large time constant, and further converts the flame into an electrical signal. The signal is converted into a binary signal with a level, and the output drives a relay via a driver, and a contact signal is output to the controller 34.

The water stone detector 30 continuously detects water m in the water supply pipe from the minimum value to the maximum value, and the detected value is transmitted to the controller 34.
Sent to the side.

When the water flow detector 31 hears one of a plurality of clicks,
When a water flow exceeding a certain level occurs in the water supply pipe, this is detected and the ON operation is activated, and when the water flow disappears, the OFF operation 1114 is activated.
'1J switch. As explained in FIG. 1, the water flow when the water flow detector 31 is turned on (Nl) is different from the water flow when it is turned on (N2) (Nl >
N2). In this way, the predetermined hysteresis width (Nl-N
The reason for 2) is to prevent it from being determined that there is no water flow due to chattering when the water flow detector 31 is turned on. This signal is the controller 34
sent to.

The water inlet humidity detector 32 is, for example, a thermister or the like,
Outputs analog voltage corresponding to incoming water temperature.

The temperature detector 33 is composed of, for example, a reamister or the like, is connected to a processing circuit within the controller 34, and outputs an analog voltage corresponding to the tapped water temperature.

The controller 34 has a target temperature setting device 35, and controls the combustion sequence from the start of combustion υ) to the stop of combustion.
It consists of a sequence circuit, a temperature control circuit that maintains the outlet S degree at a set temperature, and a fault diagnosis circuit for the water flow detector 31 according to the present invention, and these circuits are implemented by a microcomputer.

Next, the flowcharts shown from FIG. 3 onwards do not show the control procedure executed by the microcomputer, and FIG. 3 shows the overall operation of the water heater, and FIGS. 7 shows the operation of fault diagnosis of the water flow detector according to the present invention, which is executed sequentially during the overall operation of the boiler.

First, at a3 in FIG. 3, in step (2) following step (1), the state of the water flow switch 7-31 is read, and if there is water flow, the process moves to combustion start processing.

In the combustion start process, a pre-purge is first performed in step (3), and when the pre-purge time has elapsed, step (4) is performed.
In step (5) following step (5), slow ignition processing is performed.

In step (5), the electromagnetic switching valve 24 is fully opened.

The gas flow rate adjustment valve 26 is slightly opened, and while the burner 22 blows out a small amount of combustion gas 31, the igniter 27 is driven and ignition is attempted for the safety switch time.

If the burner 22 is not ignited even after the safety switch time has elapsed, step (7) is executed following step (6) to perform some error processing.

If a stone fire is confirmed before the safety switch time elapses, the hot water temperature control process is carried out in step (9) until a new water flow and no water flow are detected in step (10) a5 and step (11), respectively. If a newcomer is detected during the hot water temperature control process, the process returns to step (3) and the pre-purge process is performed again.

On the other hand, if the lack of water flow is detected immediately after the hot water exhaustion control station, step (11) is followed by step (12) to perform after-purge processing.

Also, if water flow is detected again during the afterpurge process, the process returns to step (5) following step (13) and execution starts from the slow ignition process, and if the afterpurge process has elapsed for a predetermined time, step Following (14), the process returns to step (1), the use processing.

The temperature measurement control process performed in step (9) is roughly as follows.

First, the outputs of each detector and setting device are read, and the required combustion rate and the required gas flow rate are calculated.

This calculation is performed based on the incoming water temperature, the set temperature, the outgoing water, and therefore the amount of incoming water, and the opening degree of the Jζ regas flow rate regulating valve 26 is adjusted and set based on this. Then, when the hot water outlet humidity approaches the set humidity and the rate of increase in hot water temperature decreases, the valve opening degree of the gas flow rate regulating valve 26 is finely adjusted so that the hot water outlet temperature reaches the set humidity.

In addition, when there is a change in the set temperature, the amount of inflow water corresponding to this is determined, the water amount regulator 29 is driven, and the optimum inflow water is 1fif! : Set.

The above is a feed-off type water temperature control, but the hot water temperature is a feedback type in which the deviation between the outlet temperature and the set humidity is determined, and the valve opening of the ore adjustment valve 26 is adjusted and controlled to reduce this deviation. It may also be control.

Next, the operation of fault diagnosis of the water flow detector according to the present invention will be explained.

FIG. 4 is a flowchart showing a first embodiment of the invention. In the same figure, in the first step (40>),
Turn-off operation of the water flow detector 31 is detected. This is shown in the flowchart shown in Figure 3.
2), (11) J3 and (12> to J3L).

In step (41), the detected value W1 of the water amount detector 30 is read.

In step (42), it is determined whether the read value W1 is within the normal range. As described above, the point at which the water flow detector 31 turns off is the minimum amount of inflow water necessary for combustion control of the water heater, and this minimum amount of inflow water has a predetermined value of 1.
There is a 1 volume range. As a result, if it is not within the normal range, the process proceeds to step (43), where a predetermined 1-error process is performed, and the process proceeds to step (50). The termination process in step (50) corresponds to step (12) in the flowchart shown in FIG.

On the other hand, if the determination result in step (42) is within the normal range, the process proceeds to step (44) and performs a predetermined hot water tapping process. The processing at step (44) corresponds to step (9) in the flowchart shown in FIG.

When off-operation of the water flow detector 31 is detected during the process of step (44) (step <45), step (46)
) and read the detected value W2 of the water carrier detector 30. In addition,
Step (45) similarly corresponds to steps (2>, (11) and (12) in the flowchart shown in FIG. 3).

In step (47), it is determined whether the read value W2 is within the normal range. There is a predetermined jF@ range at the time when the water flow detector 31 is turned off as well as when it is turned on. and,
If the judgment result is within the normal range, proceed to step (43), and if the judgment result is within the normal range, proceed to step (48).
Proceed to.

In step (48), the difference between the reading value W1 of the ON operation aS and the reading ffW2 of the OFF operation is determined.

In other words, increase the hysteresis width.

In step (49), it is determined whether the hysteresis width is within a predetermined range. As a result, if the result is not within the normal range, the process proceeds to step 1 (43), and if it is within the normal range, the process proceeds to step (50).

In this way, when the water flow detector 31 is turned on.

The level during off operation is constantly monitored and hysteria occurs.

As a result, deterioration of the water flow detector 31 due to aging can be quickly detected, and appropriate measures such as parts replacement can be taken.

FIG. 5 is a flowchart showing a second embodiment of the invention. Note that the same parts as in FIG. 4 are given the same reference numerals, and their explanations will be omitted.

In step (51), the reading value W1 is the minimum inflow water IN+
It is judged whether it is equal to or greater than.

In step (52), it is determined whether the reading 1 division W2 is equal to or smaller than the off-level inflow water ff1N2 during normal operation.

In other words, in this second embodiment, the water flow detector turns on even though the water flow detector is below the regular A level and therefore the amount of inflow water is small, and the water flow detector is turned on even though the water flow detector is lower than the regular A level, and the water flow sensor is turned on when the water stone is larger than the water ω corresponding to the regular A level. It deals with cases where As a result, the water flow detector 31 or the water amount detector 30
failure can be detected.

FIG. 1 is a side sectional view showing an example of a water flow detector, FIG. 2 is a basic configuration diagram of a water heater equipped with a combustion control II device having a fault diagnosis operation for a water flow detector according to the present invention, and FIG. is the above combustion 1. A flowchart showing the basic operation of the IJIII device, FIG. 4 is a flowchart showing an example of the failure diagnosis operation of the water flow detector according to the present invention performed by the combustion control device, and FIG. 5 is a flowchart showing the above failure diagnosis operation of the water flow detector. 2 is a flowchart showing other embodiments.

21...Water boiler body 22...burner 23...Heat exchanger 26...Flow rate adjustment valve Two...Water ffi regulator 30...Water amount detector 31...Water flow detector 32...Water temperature detector 33...Temperature detector 34...controller 35...Temperature setting device

Claims (1)

[Claims] (1) a water flow detector that detects the water flow of the heat exchanger, a water flow detector that detects the amount of water flowing into the heat exchanger, and a detection means that detects on/off operation of the water flow detector; reading means for taking lJ+i the detected value of the water ffl detector when the water flow detector is turned on/on in response to the operation of the detection means;
Combustion control of 11 lagoons is characterized by having a judgment means for determining whether or not the frevel level and A freckle level are normal. Device.