JP2003343923A - Safety device for water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a safety device for a water heater for surely stopping a burner when a can body is unusually heated by a failure of a hot-water temperature sensor or boiling with no water. <P>SOLUTION: A combustion chamber 3 is arranged in a lower part inside of the cylindrical can body 1 to form a hot-water storage chamber 4 between the top plate 1a of the can body 1 and the top plate 3a of the combustion chamber and in a clearance between the can body 1 and a side wall 3b of the combustion chamber. A plurality of flue pipes 5 for communicating the combustion chamber 3 with an exhaust chamber 2 are fitted between the top plate 1a and the top plate 3a of the combustion chamber 3, and a water supply pipe 7 is opened in a lower part of a side wall of the can body 1, and a hot-water discharge pipe 8 is opened in an upper part of the side wall of the can body 1, and a hot-water temperature sensor 9 is fitted to the side wall of the can body 1 at a position between the water supply pipe 7 and the hot-water discharge pipe 8. A temperature excessive-rise preventing device 10 is fitted between the hot-water discharge pipe 8 and the hot-water temperature sensor 9, and a second temperature excessive-rise preventing device 11 having operation temperature lower than that of the temperature excessive-rise preventing device 10 is fitted at the same height or lower with/than the hot-water temperature sensor 9. When the hot-water temperature sensor 9 is failed, the second temperature excessive-rise preventing device 11 works, and when the can body 1 is boiled with no water, the temperature excessive-rise preventing device 10 works to stop the combustion of the burner 6. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for a water heater for stopping the combustion of a burner when the can body is abnormally heated due to a malfunction of the hot water temperature sensor or the water heating.

[0002]

2. Description of the Related Art A combustion chamber with a burner is arranged inside a can body, and a plurality of flue pipes are attached between a top plate and a combustion chamber top plate. There is known a water heater which constitutes a heat exchange part having a heat transfer area of the upper plate of the can body and heats water stored in the can body.

Then, a water supply pipe for supplying cold water is opened in the lower side wall of the can body, a hot water outlet pipe for taking out hot water is opened in the upper side wall of the can body, and when the user opens the faucet to use the hot water, the amount of hot water used is stored. In order to supplement the room, cold water is supplied from the water supply pipe to the hot water storage room inside the can.

A hot water temperature sensor is provided on the side wall of the can body, and a temperature setting unit is provided at the operation unit. When the hot water temperature sensor detects a temperature equal to or lower than the temperature set by the operation unit, a burner command is issued to the burner to perform combustion. Is started, and the amount of heat generated by the burner is selected according to the signal from the hot water temperature sensor to obtain hot water having the hot water temperature set by the operation unit.

Generally, the hot water temperature sensor is attached to the side wall of the can between the water supply pipe and the hot water discharge pipe to detect a change in the water temperature early and issue a combustion request to the burner. Even if it takes a certain time to transition to combustion,
Stable hot water with no fluctuations in hot water temperature can be taken out.

On the other hand, if the hot water temperature sensor fails and the hot water temperature cannot be detected, the burner will continue to burn even if the set temperature is exceeded. Therefore, the burner combustion is stopped before the hot water in the hot water storage room boils. A safety device is required for this. As a countermeasure against this, an overheat prevention device is installed on the side wall of the can between the hot water pipe and the hot water sensor, and when the temperature of the side wall of the can rises due to a failure of the hot water sensor, the overheat prevention device operates. By stopping the burner combustion, boiling can be prevented when the hot water temperature sensor fails.

If the burner burns in a state where the amount of hot water in the hot water storage chamber is small and the upper part of the can body is not heated, the can body may overheat and serious troubles such as perforation may occur. However, since the overheat prevention device operates at this time as well to stop the burner, it is possible to prevent the can body from being dry-heated.

[0008]

The water heater having the above structure is
The temperature of the upper part of the can rises due to post-boiling after the burner is stopped, and the hot water temperature at the upper part of the can is higher than that near the hot water temperature sensor.The operating temperature of the overheat prevention device rises after the burner is stopped. Even if there is, it must be set to a temperature at which the water above the can does not boil.

On the other hand, the operating temperature of the overheat prevention device is set higher than the burner stop temperature when the set temperature is maximized so that the hot water temperature sensor does not malfunction when the burner stops by detecting the set temperature. In order to reliably prevent boiling when the hot water temperature sensor fails, it is better to lower the operating temperature of the overheat prevention device, and to lower the operating temperature of the overheat protection device. Must lower the mounting position of the overheat prevention device to a position where the temperature rise is small after the burner is stopped.

Further, when the burner is operated in a state where the amount of hot water in the hot water storage chamber is small, even if the temperature of the upper side wall of the can body without hot water rises, the temperature does not easily rise on the lower side wall of the can body with hot water. If the mounting position of the temperature rise prevention device is lowered, the operation is delayed, and there is a risk that the water heating is repeated at the upper part of the can body before the temperature rise prevention device operates.

However, if the mounting position of the overheat prevention device is increased in order to prevent repeated heating in the upper part of the can body, the operating temperature of the overheat protection device must be raised, and when the hot water temperature sensor fails. There is a risk of boiling, and the development of a safety device that can handle both when the hot water temperature sensor fails and when the hot water sensor is empty has been a challenge.

[0012]

The present invention solves the above-mentioned problems by providing an exhaust chamber 2 adjacent to a top plate 1a of a cylindrical can body 1 and inside the lower part of the can body 1. Is a combustion chamber 3 in which the combustion chamber top plate 3a faces the top plate 1a and the lower end of a cylindrical combustion chamber side wall 3b is connected to the can body 1. The top plate 1a of the can body 1 and the combustion chamber top plate are arranged. 3a and the space between the can body 1 and the combustion chamber side wall 3b constitute a hot water storage chamber 4, and a plurality of flue pipes 5 are attached between the top plate 1a and the combustion chamber top plate 3a to burner the burner. The combustion chamber 3 connected to 6 and the exhaust chamber 2 are communicated with each other, and the water supply pipe 7 is provided on the lower side wall of the can body 1.
A hot water outlet pipe 8 is opened on the upper side wall of the can body 1, a hot water temperature sensor 9 is attached to the side wall of the can body 1 between the water supply pipe 7 and the hot water discharge pipe 8, and a space between the hot water pipe 8 and the hot water temperature sensor 9 is provided. In the water heater in which the overheating prevention device 10 is attached to the side wall of the can body 1, the second overheating prevention device 11 is attached to the side wall of the can body 1 at the same height as or above the hot water temperature sensor 9, The operating temperature of the second overheat prevention device 11 is set lower than the operating temperature of the overheat protection device 10.

A warning means 12 is provided which is activated when the temperature of the can 1 rises abnormally. When the overheat prevention device 10 or the second overheat prevention device 11 is activated,
The burner 6 is stopped and the warning means 12 is activated, and the warning means 12 issues different alarms when the overheat prevention device 10 is activated and when the second overheat prevention device 11 is activated. Since it can be determined whether the hot water temperature sensor 9 is out of order or is not heated, it is possible to easily deal with it.

[0014]

When the hot water temperature sensor 9 mounted on the side wall of the can body 1 detects a temperature equal to or lower than the set temperature, the burner 6 is burned to boil the hot water in the can body 1 to the set temperature, and the hot water temperature sensor 9 is set. When the temperature equal to or higher than the predetermined temperature is detected, the combustion of the burner 6 is stopped, and the burner 6 repeats the combustion and the stop to obtain hot water of the set hot water temperature.

On the other hand, when the hot water temperature sensor 9 fails, the combustion of the burner 6 does not stop even if the set temperature is exceeded, so it is necessary to stop the burner 6 before the hot water in the hot water storage chamber 4 boils. In the present invention, the overheat prevention device 10 is attached to the side wall of the can body 1 between the hot water discharge pipe 8 and the hot water temperature sensor 9, and the second temperature is provided on the side wall of the can body 1 at the same height as or below the hot water temperature sensor 9.
Since the overheat prevention device 11 is attached to the second overheat prevention device 11, there is almost no temperature increase near the second overheat prevention device 11 after the burner 6 is stopped. It can be set lower than the operating temperature of the excessive rise prevention device 10.

When the combustion of the burner 6 does not stop even when the set temperature exceeds the set temperature due to the failure of the hot water temperature sensor 9, the second overheat prevention device 11 having a low operating temperature operates to stop the combustion of the burner 6. Therefore, the hot water temperature above the can body 1 after the burner 6 was stopped could be kept low.

On the other hand, when the burner 6 burns when the amount of water in the hot water storage chamber 4 is low and the temperature of the upper portion of the can body 1 without water rises, the overheat prevention device 10 operates to burn the burner 6. Since it stops, it is possible to prevent the water heating.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the embodiments shown in the drawings. 1 is a cylindrical can body, 1a is a top plate of the can body 1, 3 is a combustion chamber provided inside the lower part of the can body, and 3a is an upper chamber. A combustion chamber top plate facing the face plate 1a, 6 is a burner looking into the combustion chamber 3, and the lower end of the combustion chamber 3 is connected to the can body 1 to have a double structure to prevent the flame of the burner 6 from being generated. It is blowing into the combustion chamber 3.

Reference numeral 5 is a plurality of flue pipes mounted between the upper plate 1a and the combustion chamber top plate 3a, 2 is an exhaust chamber provided adjacent to the upper portion of the upper plate 1a, and 13 is connected to the exhaust chamber 2. The combustion gas in the combustion chamber 3 is sent to the exhaust chamber 2 through the inside of the flue pipe 5, and is exhausted from the exhaust pipe 13 to the outside.

Reference numeral 4 denotes an upper plate 1a of the can body 1 and a combustion chamber top plate 3a.
, And a hot water storage chamber constituted by a gap between the can body 1 and the combustion chamber side wall 3b, 7 is a water supply pipe opened on the lower side wall of the can body 1, and 8 is hot water discharged on the upper side wall of the can body 1. Tube, 14
Is a pressure reducing valve mounted in the middle of the water supply pipe 6, and when tap water (not shown) is opened, tap water sent from the water supply pipe 7 is reduced by the pressure reducing valve 14.
Then, the water is depressurized to a predetermined water pressure and sent to the hot water storage chamber 4.

Reference numeral 15 is a burner control means for issuing a combustion command to the burner 6, 16 is a temperature setting unit for determining the hot water discharge temperature of the water heater, and 9 is a side of the flue pipe 5 between the water supply pipe 7 and the hot water discharge pipe 8. A hot water temperature sensor provided on the side wall of the can body 1 of the
The water temperature inside is detected by the hot water temperature sensor 9, and when the temperature set by the temperature setting unit 16 or less is detected, the burner control means 1
5 issues a combustion command to the burner 6 to boil the water stored in the hot water storage chamber 4 to the designated temperature.

When the faucet is opened, the hot water heated in the hot water storage chamber 4 is discharged from the hot water outlet pipe 8, and if cold water enters the hot water storage chamber 4 instead, the hot water temperature sensor 9 detects this and operates the burner 6 again. The hot water of a predetermined temperature can be continuously supplied.

When the hot water temperature sensor 9 fails, the burner 6 continues to burn even if the set temperature is exceeded, so a safety device is required to stop the burner 6 before the hot water in the hot water storage chamber 4 boils. . Reference numeral 10 is an overheat prevention device formed of bimetal provided on the side wall of the can body 1 between the tap water pipe 8 and the hot water temperature sensor 9. Even if the hot water temperature sensor 9 fails and the burner 6 exceeds the set temperature, The combustion is continued, and when the can body 1 reaches a high temperature, it operates to stop the combustion of the burner 6.

The operating temperature of the overheat prevention device 10 is set higher than the stop temperature of the burner 6 when the set temperature is maximized, so that the hot water temperature sensor 9 does not malfunction when operating normally. It is like this.

On the other hand, when the burner 6 burns in a state where the amount of hot water in the hot water storage chamber 4 is small, the upper side of the can body 1 without hot water becomes empty and the side wall of the can body 1 is abnormally heated. Even at this time, the burner 6 is operated to stop the combustion. At this time, the temperature of the upper side of the can body 1 without hot water becomes high, but the temperature of the side wall of the lower part of the can body 1 with hot water is almost the same as the normal temperature.
If the mounting position is low, the operation is delayed and the upper part of the can body 1 is repeatedly boiled, which may cause serious trouble such as perforation and cracking of the can body 1.

For this reason, it is necessary to attach the overheat prevention device 10 to the upper part of the can body 1 as much as possible. However, the temperature of the burner 6 rises rapidly during combustion in the upper part of the can body 1, and after the burner 6 is stopped, it is caused by post-boiling. Since there is a temperature rise and the hot water temperature in the upper part of the can body 1 after the burner 6 is stopped becomes higher than that in the vicinity of the hot water temperature sensor 9, when the overheat prevention device 10 is attached to the upper part of the can body 1, the overheat prevention function is performed. When the operating temperature of the device 10 becomes high and the operation of the overheat prevention device 10 is delayed, there is a risk of boiling the hot water above the can body 1.

As a concrete example, when the stop temperature of the burner 6 when the set temperature is the highest is 65 ° C., the temperature of the upper part of the can 1 when the burner 6 is stopped is about 70 ° C. After this, the temperature rises due to post boiling
It rose to near ℃.

Therefore, the operating temperature of the overheat prevention device 10 is set to 85 ° C. so that the overheat prevention device 10 does not malfunction when the hot water sensor 9 operates normally. In case of failure of the can 1 after the burner 6 is stopped
When the temperature of the hot water in the upper part rises to around 95 ° C. and the operation of the overheat prevention device 10 is delayed, the can body 1
The hot water on the top sometimes exceeded 100 ° C.

The present invention solves the above-mentioned problems.
Reference numeral 11 denotes a second overheat prevention device provided at the same height as the hot water temperature sensor 9 or on the side wall of the can body 1 below, and the operating temperature of the second overheat prevention device 11 is overheat prevention. Device 1
Set lower than 0 operating temperature. Since there is almost no temperature increase after the burner 6 is stopped near the second overheat prevention device 11, when the stop temperature of the burner 6 is set to 65 ° C., the operating temperature of the second overheat prevention device 11 is increased. There is no risk of malfunction if set to 75 ° C.

When the burner 6 continues to burn due to the failure of the hot water temperature sensor 9 and the temperature of the entire can body 1 rises, the second overheat prevention device 11 operates to burn the burner 6. The temperature of the upper part of the can body 1 at this time is around 80 ° C., and the temperature of the upper part of the can body 1 is around 90 ° C. even if there is a temperature rise due to post-boiling. Even if the operation of the prevention device 11 is delayed, it is possible to reliably prevent boiling.

In this way, when the hot water temperature sensor 9 fails, the second overheat prevention device 11 can be activated to stop the burner 6, so that the overheat prevention device 10 raises the operating temperature. When the burner 6 burns and abnormally heats the upper side wall of the can body 1 in a state where the amount of hot water in the hot water storage chamber 4 is small, the overheat prevention device 10 operates immediately. Since the combustion of the burner 6 is stopped, it is possible to reliably prevent the empty heating.

Reference numeral 12 is a warning means for lighting a warning lamp or sounding an alarm when the temperature of the can 1 rises abnormally,
When the overheat prevention device 10 or the second overheat prevention device 11 operates due to an abnormality in the hot water temperature sensor 9 or the empty heating of the can body 1, the warning means 12 operates to notify the operator of the abnormality. The burner 6 is stopped.

When the hot water temperature sensor 9 is out of order, the second overheat prevention device 11 is activated, and when the upper part of the can 1 is not heated, the overheat prevention device 10 is activated.
No. 2 gives a different alarm when the overheat prevention device 10 is activated and when the second overheat prevention device 11 is activated. It is possible to determine whether or not it has stopped due to empty heating, and if it is empty, operation can be resumed if the operator replenishes the hot water storage room 4 with water. On the other hand, if the hot water temperature sensor 9 fails, a specialized repair company will immediately You only have to ask for repairs, and it is now possible to easily respond to repairs.

[0034]

As described above, according to the present invention, the overheat prevention device 10 is attached to the side wall of the can body 1 between the tap pipe 8 and the hot water temperature sensor 9, and the hot water temperature sensor 9 has the same height or lower side. The second overheat prevention device 11 is attached to the side wall of the can body 1 of No. 2, and there is almost no temperature increase after the burner 6 is stopped in the vicinity of the second overheat prevention device 11. The operating temperature of the excessive temperature rise prevention device 11 can be set lower than the operating temperature of the excessive temperature rise prevention device 10.

Therefore, when the temperature of the entire can body 1 rises due to the failure of the hot water temperature sensor 9, the second overheat prevention device 11 having a low operating temperature operates to stop the combustion of the burner 6, Since the temperature of the hot water in the upper part of the can body 1 after the burner 6 was stopped could be lowered, there is no fear that the hot water in the upper part of the can body 1 would boil even if the operation of the second overheat prevention device 11 was delayed.
It became possible to prevent the boiling surely.

On the other hand, when the upper part of the can body 1 is boiled empty, the overheat prevention device 10 can be activated to stop the combustion of the burner 6, so that even when hot water is near the hot water temperature sensor 9, it is empty. It is possible to realize a highly reliable structure as a safety device that can cope with both the failure of the hot water temperature sensor 9 and the empty heating of the can body 1 without repeating the heating.

Further, since the warning means 12 for issuing a different alarm when the overheat prevention device 10 is activated and when the second overheat prevention device 11 is activated is provided, the hot water temperature sensor 9 is stopped due to a failure or is not heated. It is now possible to easily determine whether or not the vehicle has stopped, and it is possible to easily respond to repairs.

[Brief description of drawings]

FIG. 1 is a sectional view of a water heater showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a water heater showing another embodiment of the present invention.

[Explanation of symbols]

1 can 1a Top plate 2 exhaust chamber 3 Combustion chamber 3a Combustion chamber top plate 3b Combustion chamber side wall 4 Hot water storage room 5 flue pipe 6 burners 7 water supply pipe 8 Hot water pipe 9 Hot water sensor 10 Overheat prevention device 11 Second overheat prevention device 12 Warning means

Claims (2)

[Claims] 1. An exhaust chamber 2 is provided adjacent to an upper surface plate 1a of a cylindrical can body 1, and a combustion chamber top plate 3a is arranged inside the lower part of the can body 1 so as to face the upper surface plate 1a and is cylindrical. Combustion chamber side wall 3
A combustion chamber 3 whose lower end is connected to the can body 1 is arranged, and hot water is stored between the upper plate 1a of the can body 1 and the combustion chamber top plate 3a and between the can body 1 and the combustion chamber side wall 3b. A chamber 4 is formed, and a plurality of flue pipes 5 are attached between the upper surface plate 1a and the combustion chamber top plate 3a to connect the burner 6 to the combustion chamber 3 and the exhaust chamber 2, and the can body is connected. 1 Water supply pipe 7 on the lower side wall,
A hot water outlet pipe 8 is opened on the upper side wall of the can body 1, a hot water temperature sensor 9 is attached to the side wall of the can body 1 between the water supply pipe 7 and the hot water discharge pipe 8, and a space between the hot water pipe 8 and the hot water temperature sensor 9 is provided. In the water heater in which the overheating prevention device 10 is attached to the side wall of the can body 1, the second overheating prevention device 11 is attached to the side wall of the can body 1 at the same height as or above the hot water temperature sensor 9, A safety device for a water heater, wherein the operating temperature of the second overheat prevention device 11 is set lower than the operating temperature of the overheat protection device 10. 2. A warning means 12 that operates when the temperature of the can 1 rises abnormally is provided, and the burner 6 is stopped when the overheat prevention device 10 or the second overheat prevention device 11 operates. Along with this, the warning means 12 is activated, and the warning means 12 issues a different alarm when the overheat prevention device 10 is activated and when the second overheat prevention device 11 is activated. Safety device for the water heater described.