JPH11141982A - Water heater, combustion equipment and method for displaying combustion state of the heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water heater for preventing an erroneous operation for lighting a combustion lamp during non-combustion due to a repetition of a combustion operation for a short time by preventing lighting of the lamp during a heat insulation operating with a simple circuit configuration, a combustion equipment and a method for controlling a combustion state of the heater. SOLUTION: A heat insulating operation controller 51 intermittently burns a burner in the state without water flow to heat insulate hot water in a heat exchanger within a predetermined temperature range. And, a flame sensor 54 senses a flame output from the burner via a flame rod 32 regardless of whether it is during a heat insulation operating or not. A combustion state display unit 53 displays the fact that the burner is burning only at the time of sensing the flame continuously for a predetermined time or more by the sensor 54 by lighting a combustion lamp 15. That is, it displays the fact that the burner is under combustion during a period from the time when the sensor 54 senses the flame continuously for a predetermined time or more to the time when it does not sense the flame.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater, a combustion device, and a water heater having a function of burning a burner in a state where no water flows and keeping the hot water in a heat exchanger ready for the next hot water. The present invention relates to a combustion state display method.

[0002]

2. Description of the Related Art In a conventional water heater, in order to further improve the comfort of the water heater, the hot water in a heat exchanger without water flow is supplied in order to supply hot water of almost a set temperature from the beginning of tapping. Some have a function of keeping the temperature within a predetermined temperature range. In such a water heater, the temperature of the hot water in the heat exchanger is monitored by a temperature sensor, and when the temperature of the hot water falls below the allowable lower limit temperature,
A heat retaining operation such as burning the burner for a short time of, for example, about 2 seconds while the plug is not opened is performed to keep the hot water in the heat exchanger within the target temperature range.

[0003] In a water heater, flame coming out of a burner is usually detected by a flame rod electrode, and whether or not the burner is burning is indicated by lighting a combustion lamp or the like.

[0004] By the way, the combustion by the above-mentioned heat retaining operation is as follows.
The water heater itself performs the operation autonomously based on the temperature of the water in the heat exchanger, and does not involve any operation such as opening a water faucet as in the case of tapping water. And cause anxiety. Therefore, conventionally, it was determined whether or not the combustion of the burner was caused by the heat retaining operation, and the combustion based on the heat retaining operation was controlled so as not to turn on the combustion lamp.

[0005]

However, in such a conventional technique, it is necessary to determine whether or not the combustion of the burner is based on a heat retaining operation, and a circuit configuration for controlling the lighting of the combustion lamp is required. However, there was a problem that it became complicated.

[0006] In addition, there is a certain time delay in the flame detection by the flame rod electrode. Therefore, there is a slight difference between a period in which the burner is actually burning and a period in which the flame is detected by the flame rod electrode. For this reason, even if the combustion is not based on the heat retention operation, if the short-time hot water supply operation is repeated at short time intervals, a malfunction such as a combustion lamp being turned on during a period in which the burner is not actually burning occurs. I was

The present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to prevent a combustion lamp from being turned on during a warming operation by a simple circuit configuration, and to provide a short-time combustion. An object of the present invention is to provide a water heater, a combustion device, and a method for controlling a combustion state of a water heater that can prevent a malfunction in which a combustion lamp is turned on during non-combustion due to repetition of operation.

[0008]

The gist of the present invention to achieve the above object lies in the following inventions. [1] In a water heater having a function of burning a burner (22) in a state where there is no flow of water and keeping the hot water in a heat exchanger (23) ready for the next hot water supply, the water heater operates to keep warm. Control means (51), flame detection means (32, 54) for detecting flame from the burner (22), and combustion state display means (53, 54) for displaying whether or not the burner (22) is burning. 15), and the thermal insulation operation control means (5)
1) intermittently burning the burner (22) in a state where there is no water flow to keep the hot water in the heat exchanger (23) within a predetermined temperature range, and to display the combustion state display means (53, 15). )
The hot water supply device displays an indication that the burner (22) is burning only when the flame detecting means (32, 54) continuously detects a flame for a predetermined time or more.

[2] Burner (22) without water flow
The hot water in the heat exchanger (23) is prepared for the next hot water supply by heating the hot water in the heat exchanger (23). The water heater includes a heat retaining operation control means (51) and the burner (2).
Flame detection means (32, 54) for detecting flame emitted from 2)
And a combustion state display means (53, 15) for displaying whether or not the burner (22) is burning. 22) is intermittently burned to heat exchanger (2).
3) Keeping the hot water in a predetermined temperature range, and the combustion state display means (53, 15) is provided with the flame detection means (32, 5).
(4) The water heater displays an indication that the burner (22) is burning during a period from when the flame is continuously detected for a predetermined time or longer until the flame is no longer detected.

[3] In a combustion device having a function of displaying whether or not the burner (22) is burning, flame detecting means (32, 5) for detecting a flame coming out of the burner (22).
4) and combustion state display means (53, 15) for displaying whether or not the burner (22) is burning. The combustion state display means (53, 15) is provided with the flame detection means (53, 15). 32, 54), only when the flame is detected for a predetermined time or more, an indication that the burner (22) is burning is displayed.

[4] Burner without water flow (22)
In a method for displaying the combustion state of a water heater having a function of keeping the hot water in the heat exchanger (23) ready for the next hot water by burning the burner, the burner (22) continuously burns for a predetermined time or more. A display indicating that the burner (22) is combusting only when the burner is in operation.

The present invention operates as follows. The heat retaining operation control means (51) controls the burner (2) in a state where there is no water flow.
2) intermittently burn to keep the hot water in the heat exchanger (23) within a predetermined temperature range, and the flame detecting means (32, 54)
The flame emitted from the burner (22) is detected irrespective of whether or not the heat retaining operation is being performed. Combustion state display means (53, 15)
Indicates that the burner (22) is burning only when the flame detecting means (32, 54) continuously detects the flame for a predetermined time or more. That is, the flame detecting means (32, 5
From 4) when the flame is continuously detected for a predetermined time or longer to when the flame is no longer detected, an indication that the burner (22) is burning is displayed.

As described above, the display that the burner (22) is burning is performed only when the combustion has continued for a predetermined time or more. It is possible to prevent a combustion lamp or the like from lighting. In addition, since it is determined whether or not to display that combustion is being performed based on the time elapsed since the flame was detected, when it is determined whether or not the current combustion is based on the heat retention operation, In comparison, the circuit configuration can be simplified.

Further, since the display indicating that the combustion is being performed is performed only when the combustion continues for a predetermined time or more, the burner (22) actually burns even if the short-time hot water supply operation is repeatedly performed separately from the heat retaining operation. It is possible to prevent a malfunction such as a case where the combustion lamp is turned on during a period in which it is not performed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Each drawing shows an embodiment of the present invention. As shown in FIG. 2, the water heater 10 according to the present invention
Adopts a forced exhaust (FE) system, which is installed indoors, takes in the indoor air into the appliance, supplies the burner 22, and discharges exhaust air to the outside through an exhaust pipe.

A combustion chamber 21 is provided at a substantially central portion in the housing 11, a burner 22 is provided at a lower portion thereof, and a heat exchanger 23 is provided at an upper portion for heating water by heat from the air supply port 12. Is arranged. An igniter electrode 31 functioning as an igniter and a flame rod electrode 32 for detecting a flame are provided near the combustion surface of the burner 22.
Is arranged.

At the lower left end of the combustion chamber 21, there is provided a combustion fan 24 for sending air taken in from the air supply port 12 to the burner 22, and at the center of the upper surface of the combustion chamber 21 an exhaust port 25. . An exhaust pipe (not shown) communicating with the outside is connected to the exhaust port 25.

A gas supply path 26 leading to the burner 22 has a source gas solenoid 27, a gas solenoid valve 28, a gas proportional valve 29,
Various valves such as a gas capacity switching valve 30 are attached. A water supply thermistor 34 for detecting water supply temperature, a water amount sensor 35 for detecting the presence or absence of water supply, and the like are provided in the middle of a water supply pipe 33 communicating with the inlet side of the heat exchanger 23.

The hot water supply pipe 36 extending from the outlet side of the heat exchanger 23 is provided with a water control section 37 for controlling the total flow rate of hot water to be discharged, and the water supply pipe 33 and the hot water supply pipe 36 are connected to the heat exchanger 23. Water solenoid valves 39 for controlling the bypass ratio are provided in the middle of the bypass passage 38 that connects the bypass valves. A heat exchange thermistor 40 for detecting the temperature of the hot water in the heat exchanger 23 is disposed near the outlet of the heat exchanger 23.

An operation unit 13 having an operation switch for receiving various operations such as ON / OFF of a heat retention function and setting of a tapping temperature and a small liquid crystal display are provided at a lower front portion of the housing 11. In addition, the operation unit 13 includes a combustion lamp 15 for displaying that the burner 22 is burning. In addition, the water heater 10
Has a function equivalent to that of the operation unit 13 and includes a main remote controller and a bath remote controller (not shown) installed in a kitchen or a bathroom.

At the upper right end in the housing 11, a control board 50 for controlling various controls in the water heater 10 is arranged. The control board 50 mainly includes a CPU (Central Processing Unit) (not shown), a ROM for storing programs and various fixed data, a RAM for temporarily storing data required for executing the programs, and the like. It is composed of a circuit as a unit.

FIG. 1 shows a control board 50 of the water heater 10.
Represents a functional configuration. The control board 50 includes a hot water supply operation control unit 51, a heat retention operation control unit 52, a combustion state display control unit 53, and a flame detection unit 54. The hot water supply operation control unit 51 includes a burner 22, a gas proportional valve 29, a combustion fan 24, and a water control unit 37 for discharging hot water at a set temperature.
It is a circuit part for controlling operations such as

The heat retaining operation control section 52 controls the operation when the burner 22 is intermittently burned in a state where there is no water flow to keep the hot water in the heat exchanger 23 in a predetermined temperature range in preparation for the next hot water discharge. This is the circuit part that performs. Specifically, the heat exchanger 23
The temperature of the hot water inside is monitored by the heat exchange thermistor 40, and when the hot water temperature falls below the allowable lower limit temperature, the burner 22 is burned for about 2 seconds for a short time with no water flowing, and the heat inside the heat exchanger is The hot water is kept within the target temperature range.

The flame detecting section 54 is a circuit section for detecting whether or not the burner 22 is burning through the flame rod electrode 32. The combustion state display control unit 53 includes the operation unit 1
3 is a circuit portion for controlling the lighting of the combustion lamp 15 provided in 3. The combustion state display control unit 53 includes a timer unit 55 that measures an elapsed time from the time when the flame detection unit 54 detects the flame, and 5 seconds elapse from the time when the flame detection unit 54 detects the flame. When the flame is still burning, the combustion lamp 15 is turned on.

Next, the operation will be described. Hot water supply operation control unit 51
When the water flow sensor 35 detects water flow, the combustion fan 24 is activated to pre-purge the combustion chamber 21, then the gas solenoid valve 28 and the gas proportional valve 29 are opened, and the combustion gas is sent to the burner 22, and the igniter electrode 31 Ignite by Thereafter, the gas proportional valve 29 controls the supply amount of the combustion gas and the water control unit 37 controls the total flow amount of the hot water so that hot water at the set temperature is discharged until the flow of water stops.

The heat retaining operation control section 52 monitors the temperature of the hot water in the heat exchanger 23 by the heat exchange thermistor 40 in a state where there is no water flow, and when the hot water temperature falls below the allowable lower limit temperature, the burner 22 is turned on for 2 seconds. Burn for about a short time, heat exchanger 2
Keep the hot water in 2 within the target temperature range. As a result, in the state where there is no water flow, short-time combustion of about 2 seconds is usually repeated at intervals of several minutes.

The flame detecting section 54 is connected to the frame rod electrode 32
It is always detected whether or not the burner 22 is burning. The timing unit 55 of the combustion state display control unit 53 measures the time during which the flame continues to burn from the time when the flame detection unit 54 detects the flame from the burner 22. Note that the timer 55 stops the timer operation when the flame is extinguished, and resets the measured value to “0”. The combustion state display control unit 53
The combustion lamp 15 is turned on when the measured value of the timer unit 55 exceeds 5 seconds, and turned off when the flame detection unit 54 stops detecting the flame.

FIG. 3 shows the correspondence between the combustion state 61 of the burner 22, the flame detection state 62 by the flame rod electrode 32, and the lighting state 63 of the combustion lamp 15. Each of the rectangular periods is a combustion period 61a of the burner 22,
61b, flame detection periods 62a, 62b, combustion lamp 15
In the lighting period 63a. Burner 22 is at time T
When the ignition is performed and the combustion is started, the flame rod electrode 32 detects the flame at a time T2 after a predetermined time has elapsed, and the timer 55 starts the time counting operation from the time T2.

Time T3 5 seconds after the flame is detected
Since the flame has been continuously detected even after elapse, the combustion state display control unit 53 turns on the combustion lamp 15 at time T3. Thereafter, when the burner 22 extinguishes and the flame rod electrode 32 stops detecting the flame at time T4, the combustion state display control unit 53 turns off the combustion lamp 15. When the combustion of the burner 22 continues for a certain period of time as described above, the combustion lamp 15 is turned on to display the combustion state 7 to 8 seconds after ignition.

When the temperature of the hot water in the heat exchanger 23 drops to the allowable lower limit temperature in a state where there is no water flow, the hot water supply operation control unit 51
At a time T5, the burner 22 is ignited, and thereafter, a flame is detected by the flame rod electrode 32 at a time T6 after a lapse of a predetermined time. The timer 55 starts counting the elapsed time simultaneously with the detection of the flame. However, since the combustion for keeping the temperature is completed in about 2 seconds, the flame is not detected at the time T7 about 2 seconds after the time T6. The timer 55 stops the timer operation and resets the measured value to “0”. As a result, the combustion state display control unit 53 does not turn on the combustion lamp 15 in the current combustion.

As described above, the combustion lamp 15 is turned on only when the flame is continuously detected for 5 seconds or more, so that the short-time combustion performed intermittently when the hot water in the heat exchanger 23 is kept warm. Then, the combustion lamp 15 is not turned on. Also, when the hot water supply operation for a short time is repeatedly performed, the combustion lamp 15
Is not lit, it is possible to prevent a malfunction in which the combustion lamp 15 is lit during a period in which the burner 22 is not actually burning.

In the embodiment described above, the combustion lamp 15 is turned on only when the flame is detected continuously for 5 seconds or more, but the time is not limited to 5 seconds. That is, the time during which the lighting of the combustion lamp 15 is suppressed may be set according to the length of the time delay until the flame rod electrode 32 detects the flame, the time during which the burner 22 burns by the heat retention function, and the like.

Further, in the embodiment, the combustion lamp 15 is turned on to display the combustion state of the burner 22. However, for example, a symbol or the like simulating a flame is displayed on a liquid crystal display, so that the burner 22 is displayed. May be displayed.

[0034]

According to the water heater, the combustion apparatus and the water heater control method of the present invention, the display that the burner is burning is made only when the combustion continues for a predetermined time or more. It is possible to prevent the combustion lamp from being turned on by a heat retention operation in which combustion for about 2 seconds is repeated at intervals of several minutes.

Also, since it is determined whether or not to display that combustion is taking place based on the elapsed time from the detection of the flame, it is determined whether or not the current combustion is based on the heat retention operation. Thus, the circuit configuration can be simplified as compared with the case of performing the above.

Further, since the display indicating that the combustion is being performed is performed only when the combustion continues for a predetermined time or more, separately from the heat retaining operation,
Even if hot water supply operation for a short time is repeatedly performed,
It is possible to prevent a malfunction in which the combustion lamp is turned on during a period in which the burner is not actually burning.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a water heater according to one embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a control board included in the water heater according to one embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a correspondence between a combustion state of a burner, a flame detection state by a flame rod electrode, and a lighting state of a combustion lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Water heater 13 ... Operation part 15 ... Combustion lamp 22 ... Burner 23 ... Heat exchanger 32 ... Frame rod electrode 35 ... Water amount sensor 40 ... Heat exchange thermistor 50 ... Control board 51 ... Hot water supply operation control part 52 ... Heat retention operation control part 53: combustion state display controller 54: flame detector 55: timer

Claims (4)

[Claims] 1. A water heater having a function of burning a burner in a state where there is no flow of water and keeping the hot water in a heat exchanger ready for the next hot water supply, wherein the water heater has a heat retaining operation control means, Flame detection means for detecting the flame coming out of the burner, and combustion state display means for displaying whether the burner is burning or not, the heat retention operation control means, the burner in a state without water flow, the burner The hot water in the heat exchanger is intermittently burned to keep the temperature within a predetermined temperature range, and the combustion state display means displays the burner only when the flame detection means continuously detects a flame for a predetermined time or more. A hot water heater that indicates that the fuel is burning. 2. A water heater having a function of burning a burner in a state where there is no flow of water to keep the hot water in a heat exchanger ready for the next hot water supply, wherein the water heater has a heat retaining operation control means, Flame detection means for detecting the flame coming out of the burner, and combustion state display means for displaying whether the burner is burning or not, the heat retention operation control means, the burner in a state without water flow, the burner The hot water in the heat exchanger is kept in a predetermined temperature range by intermittently burning, and the combustion state display means detects the flame from when the flame detection means continuously detects the flame for a predetermined time or more. The water heater displays an indication that the burner is burning until the burner stops. 3. A combustion device having a function of displaying whether or not a burner is burning, a flame detecting means for detecting a flame coming out of the burner, and a combustion for displaying whether or not the burner is burning. A combustion state display means, wherein the combustion state display means displays that the burner is burning only when the flame detection means continuously detects a flame for a predetermined time or more. . 4. A method for displaying a combustion state of a water heater having a function of burning a burner in a state where there is no flow of water and keeping the hot water in a heat exchanger ready for the next hot water supply, wherein the burner is operated for a predetermined time or more. A method for displaying a combustion state of a water heater, wherein an indication that the burner is burning is displayed only when burning is continued.