JPH07294007A - Drain plug leak detection device for water heaters - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a drain plug leak detection device for a water heater that can promptly and reliably detect a leak in the can drain plug. [Constitution] Inlet pipe 11, instant heat exchange can body 10, burner 16,
It has a tap pipe 12, a bypass pipe 13, and a mixing controller 14.
In a water heater in which a water flow rate sensor 21 for detecting the flow rate of water flowing into the instantaneous heat exchange can body 10 is provided in the middle of the water supply pipe 11 and a can body drain plug 19 is provided at the downstream position thereof. This is a drain plug leakage detection device, in which the hot water supply pipe 15
If the temperature detected by the hot water supply temperature sensor 24 provided in the temperature is less than the lower limit temperature as the hot water hot water temperature that is normally used, and the temperature rise with respect to the incoming water temperature is also less than a certain value for a certain period of time, A controller 30 for determining that the drain plug 19 has a leak is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drain plug leak detection device for a water heater, which detects water leaking from a can drain plug of the water heater.

[0002]

2. Description of the Related Art Conventionally, in a water heater such as an oil water heater having an instantaneous heat exchange can body, in order to drain water from the instantaneous heat exchange can body due to a layout relationship and prevention of freezing in winter. In some cases, the can body drain plug provided on the downstream side is disposed downstream of the position of the water flow rate sensor of the water inlet pipe.

[0003]

However, as described above, in the water heater in which the can body drain plug is arranged downstream of the position of the water flow rate sensor of the water inlet pipe, the can body drain plug is out of order and may cause other problems. If the hot water supply operation switch is turned on or the hot water supply kerran is subsequently opened to use hot water when the water flow sensor detects more than the minimum operating water volume, the controller will Assuming that all the flow rates detected by the writing water flow rate sensor pass through the instantaneous heat exchange can body, the required combustion heat quantity of the burner is calculated and combustion is started. However, when all the water flowing through the water inlet pipe flows out from the can body drain plug and does not flow to the instantaneous heat exchange can body, it becomes empty heating of the instantaneous heat exchange can body and There has been a problem that the thermal fuse is melted, and the combustion wall of the instant heat exchange can body is melted, causing abnormal combustion.

Therefore, the present invention solves the above-mentioned drawbacks of the conventional device, and when the can body drain plug is leaking, can detect the drain plug leak quickly and surely. For the purpose of providing.

[0005]

In order to achieve the above object, a drain plug leak detection device for a water heater according to the present invention uses a burner to heat water entering from a water inlet pipe through an instantaneous heat exchange can body, and discharges the water to a hot water outlet pipe. At the same time, a part of the incoming water is mixed with the hot water from the bypass pipe through the mixing adjuster to adjust the hot water to the set hot water temperature and supply the hot water to the hot water supply pipe. A drain plug leak detection device in a water heater equipped with a water flow rate sensor for detecting the flow rate of water flowing into the instant heat exchange can body along the way and a can body drain plug at the downstream position. The temperature detected by the hot water supply temperature sensor provided in the hot water supply pipe is less than the lower limit temperature as the hot water hot water supply temperature that is normally used, while the incoming water flow sensor detects the minimum working water amount or more and is burning. If the temperature rises to water temperature is also below a certain state has continued for a predetermined time is characterized in that a controller determines that the leakage is present in the can body discharge valve.

[0006]

According to the features of the present invention described above, when the hot water supply operation switch is turned on, the water flow rate sensor causes the amount of water input to exceed the minimum operating water amount due to leakage of the can drain plug or opening of the hot water supply When the flow rate is detected, combustion of the burner is started, hot water is discharged through the instantaneous heat exchange can body, water from the bypass pipe is mixed appropriately, and hot water of a predetermined set hot water temperature is supplied to the hot water supply pipe. Supplied. When combustion is started when the water flow rate sensor detects a minimum working water amount or more, the controller monitors the temperature detected by the hot water supply temperature sensor, and the temperature detected by the hot water supply temperature sensor is the hot water supply that is normally used. When the temperature is lower than the lower limit temperature and the temperature rise with respect to the incoming water temperature is also less than a certain value, the controller determines that the can body drain plug has a leak when the state continues for a certain time. If it is normal, after starting combustion for a while,
The hot water supply temperature rises above the minimum level of the hot water supply temperature that is normally used, and even if the set hot water supply temperature is set to a value below the minimum level, it will rise above a certain temperature above the incoming water temperature for a while after a while. Should be. Therefore, if this is not the case, it is not normal and it is judged that there is a leak in the can drain plug. If the temperature detected by the hot water supply temperature sensor is below the lower limit of the hot water supply temperature that is normally used, and the temperature rise relative to the incoming water temperature is also below a certain level and that state continues for a certain period of time, Since it is determined that the water is leaking from the stopper, it is possible to detect the leakage of the can drain plug relatively quickly and early before the instantaneous heat exchange can body is damaged by heat due to empty heating. The determination uses only the temperature detected by the hot water supply temperature sensor and its duration as the determination item. Since no flow rate element is included, a relatively simple leak determination mechanism and less erroneous detection can be achieved. Since it is constantly monitoring during combustion, even if it is considered normal because both the hot water supply and the can drain are open, when the hot water is closed, the can drain leaks at that time. Can be detected. In addition, the judgment is made by keeping a certain temperature condition for a certain time.Therefore, false detection due to temporary hot water supply due to post-boiling during hot water re-supply can be eliminated, and leakage of the can body drain plug can be ensured. Can be detected.

[0007]

EXAMPLES The present invention will be described below based on examples.
FIG. 1 is an overall configuration diagram of a water heater equipped with the device of the present invention, and FIG.
6 is a flowchart illustrating a drain plug leak detection mechanism by a controller.

First, the water heater shown in FIG. 1 will be described. This water heater also has equipment for reheating the bath, and in addition to the instant heat exchange can body 10 for hot water hot water supply, the instant heat heater for bath heating. An exchange can body 50 is provided. In the present invention, since there is no direct relationship with the reheating of the bath, the description thereof will be omitted. The water heater comprises the instantaneous heat exchange can body 10, a water inlet pipe 11 for sending water to the instant heat exchanger canister 10, a hot water outlet pipe 12 for hot water heated by the heat exchange canister 10, and a water outlet pipe 12 from the water inlet pipe 11. A bypass pipe 13 for bypassing water to the water, a mixing controller 14 for mixing and adjusting water from the bypass pipe 13 and hot water from the hot water outlet pipe 12, and hot water supply connected to the downstream of the mixing controller 14. With tube 15.

The instant heat exchange can body 10 is heated by a burner 16 such as a petroleum burner. The can body 10 is provided with a can body temperature fuse 17. The water inlet pipe 11 is provided with a water inlet flow rate sensor 21 and a water inlet temperature sensor 22. Further, the drain pipe 18 is provided on the downstream side of the position of the water flow rate sensor 21 of the water pipe 11.
The drain pipe 18 is provided with a can body drain plug 19 for draining residual water and the like in the can body 10. The hot water outlet pipe 12 is provided with a hot water outlet temperature sensor 23. The hot water supply pipe 15 is provided with a hot water supply temperature sensor 24 and an overflow prevention device 25. Further, 30 is a controller, and this controller 30 controls the entire apparatus, and includes an incoming water flow rate sensor 21, an incoming water temperature sensor 22, a hot water temperature sensor 23,
Information from the hot water supply temperature sensor 24 and other sensors is input, and information on the hot water supply temperature set by a remote controller (not shown) is input to perform necessary calculations, and necessary commands are given to the burner 16 and the can body drain plug 19 , Send to others.

In the above-mentioned water heater, with the hot water supply operation switch of the device being turned on, the hot water supply lan (not shown) is opened as a normal operation, so that the incoming water flow rate sensor 21
When a flow rate equal to or higher than the minimum working water amount (MOQ) flows into the fuel cell, combustion operation is started. Hot water is discharged from the water inlet pipe 11 through the heat exchange can body 10 to the hot water outlet pipe 12, and the water from the bypass pipe 13 is appropriately adjusted with respect to the hot water from the hot water outlet pipe 12 by the mixing controller 14 and set. Hot water adjusted to the hot water supply temperature flows into the hot water supply pipe 15. Further, the can body drain plug 19 can be automatically and manually opened / closed by the controller 30 as required. By opening the can body drain plug 19, it is possible to prevent freezing in the winter and to drain residual water in the instantaneous heat exchange can body 10 when necessary. On the other hand, when the can body drain plug 19 is opened due to a failure or other reasons, water leaks from the can body drain plug 19, so when the leak amount is equal to or more than the minimum operating water amount (MOQ), Burning of the burner starts even when the hot water supply switch is not turned on, even if the hot water supply switch is not turned on, and the combustion continues even if the hot water supply run is closed from the open state. Abnormal combustion.

It prevents the abnormal combustion as described above from continuing,
A mechanism for detecting a leak of the can body drain plug 19 by the controller 30 before the can body temperature fuse is blown and before the can body is thermally damaged will be described with reference to FIG. Now, when the hot water supply operation switch of the water heater is turned on (YES in S1), that is, when the water of the minimum operating water amount or more flows through the water inlet pipe 11, the water flow rate sensor 21 generates a water flow of the minimum operating water amount (MOQ) or more. When the burner 16 is turned on and combustion is started when it is detected, when the incoming water flow rate sensor 21 actually detects the minimum operating water amount (MOQ) or more (Yes in S2), the combustion of the burner 16 is started (S3). .

Under the condition that the burner 16 is burning, the controller 30 starts monitoring the temperature detected by the hot water supply temperature sensor 24. That is, during combustion, the controller 30 determines whether the hot water supply temperature detected by the hot water supply temperature sensor 24 is higher by 10 ° C. or more than the hot water temperature detected by the hot water temperature sensor 22 (S4).
It is determined whether the hot water supply temperature is 30 ° C or higher (S5), and if none of the conditions are satisfied (No in S4, No in S5), it is monitored whether the state continues for 18 seconds. (S6) If it continues for 18 seconds or longer (Yes in S6), the controller 30 determines whether there is a leak in the can body drain plug 19 and issues a safety operation command (S7).

In step S4, 10 ° C. when the hot water supply temperature is 10 ° C. or more higher than the incoming water temperature detected by the incoming water temperature sensor 22 is not limited to this value. Sufficient evidence that the water was heated through the instant heat exchange can body if the detected hot water temperature was low, less than 30 ° C, but still had a significant temperature rise relative to the water temperature. As a rise temperature that can be such evidence, even if it is something other than 10 ° C, for example, a temperature of about 5 ° C to 15 ° C should be appropriately selected and set according to the shape and size of the water heater. You can Further, in step S5, 30 ° C. when the hot water supply temperature is 30 ° C. or higher is not limited to this value. The above-mentioned 30 ° C. has a meaning as a lower limit temperature of the hot water hot water supply temperature which is generally and usually set when a water heater is used. Therefore, as the lower limit temperature of the general hot water supply temperature, for example, 20
A value of ℃ to 30 degrees can be appropriately selected and set.
Furthermore, in step S6, 18 seconds whether or not 18 seconds have continued is not limited to this. These 18 seconds are
Since the constant temperature condition of No in steps S4 and S5 continues for a certain period of time, it has a meaning to eliminate an erroneous determination due to a temporary hot water supply such as after-boiling at the time of re-hot water supply. It is a thing. The duration can be set, for example, by appropriately selecting a time of about 10 seconds to about 30 seconds according to the shape and size of the water heater. In step S7, the safe operation is to completely stop the combustion operation of the burner 16, for example.

If a more reliable determination is desired, a condition that the change in the water flow rate detected by the water flow rate sensor 21 is less than a certain value can be added between the steps S5 and S6. That is, when the incoming water flow rate greatly increases on the way, the hot water supply temperature may not continue to rise sufficiently and may continue to be low, but it is meaningful to eliminate such a case and make a more reliable determination. . But,
It is necessary to constantly monitor changes in the flow rate, which makes the mechanism difficult.

[0015]

According to the present invention, which has the above-described structure,
According to the drain plug leak detection device for a water heater described in (1), the hot water supply is normally used when the temperature detected by the hot water supply temperature sensor provided in the hot water supply pipe is detected during the combustion by the incoming water flow rate sensor detecting the minimum working water amount or more. Since it is judged that water is leaking from the can drain plug when the temperature is below the lower limit temperature and the temperature rise against the incoming water temperature is also below a certain level for a certain period of time, it can be instantaneous Before the heat exchange can body is damaged by heat, it is possible to detect the leakage of the can body drain plug relatively quickly and early. The determination uses only the temperature detected by the hot water supply temperature sensor and its duration as the determination item. Since no flow rate element is included, a relatively simple leak determination mechanism and less erroneous detection can be achieved. Since it is constantly monitoring during combustion, even if it is considered normal because both the hot water supply and the can drain are open, when the hot water is closed, the can drain leaks at that time. Can be detected. In addition, since the determination is performed by maintaining a certain temperature condition for a certain period of time, erroneous detection due to temporary hot water supply due to post-boiling during hot water re-supply is eliminated,
Leakage of the can drain plug can be reliably detected.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a water heater equipped with the device of the present invention.

FIG. 2 is a flowchart illustrating a drain plug leak detection mechanism by a controller.

[Explanation of symbols]

 10 Instantaneous heat exchange canister 11 Inlet pipe 12 Outlet pipe 13 Bypass pipe 14 Mixing controller 15 Hot water supply pipe 16 Burner 18 Drain pipe 19 Can body drain plug 21 Inlet flow sensor 22 Inlet temperature sensor 23 Outlet temperature sensor 24 Hot water temperature sensor 30 controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuyuki Emoto 32 No. Akashi-cho, Chuo-ku, Kobe-shi, Hyogo In stock company Noritsu

Claims (1)

[Claims] 1. The water from the water inlet pipe is heated by a burner through an instantaneous heat exchange can body to be discharged to a hot water outlet pipe, and at the same time, a part of the water is mixed with the hot water from a bypass pipe through a mixing controller. With this, the hot water of the set hot water supply temperature is adjusted and supplied to the hot water supply pipe, and a water flow rate sensor for detecting the flow rate of the water flowing into the instantaneous heat exchange can side is provided in the middle of the water supply pipe. And a drain plug leak detection device for a water heater in which a can drain plug is provided at a downstream position thereof, wherein the inlet water flow rate sensor detects a minimum working water amount or more and is provided in a hot water supply pipe during combustion. If the temperature detected by the hot water supply temperature sensor is lower than the lower limit temperature as the hot water hot water temperature that is normally used, and the temperature rise with respect to the incoming water temperature is also lower than a certain value for a certain period of time, the can body A drain plug leak detection device for a water heater, comprising a controller for determining that the drain plug has a leak.