JP2616436B2 - Water heater drainage plug leak detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater drainage tap leak detecting device for detecting that water is leaking from a can drainage tap of a 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 in order to prevent freezing in winter due to layout reasons and in winter. In some cases, the can body drain plug provided in the water supply pipe is disposed downstream of the position of the water flow sensor in the water inlet pipe.

[0003]

However, as described above, in a water heater in which a can body drain plug is disposed downstream of a position of an inlet flow sensor of an inlet pipe, the can body drain plug may fail or have other causes. If the hot water supply operation switch is on when the hot water supply operation switch is on, the water flows into the water inlet pipe not only when the hot water supply callan is opened but also when the hot water supply callan is not opened. As a result, when the incoming water flow sensor detects more than the minimum working water amount,
The controller calculates the required amount of combustion heat of the burner assuming that all the flow rates detected by the incoming water flow rate sensor pass through the instantaneous heat exchange can, and starts combustion. Then, since the water passing through the incoming water flow rate sensor leaks from the can body drain plug, the amount of water flowing into the instantaneous heat exchange can body decreases, and the hot water discharged from the hot water is excessively heated and boiled. There has been a problem that the temperature of the exchange can body rises, causing abnormal combustion such as melting of the can body temperature fuse and melting of the body wall of the instantaneous heat exchange can body.

Accordingly, the present invention solves the above-mentioned disadvantages of the conventional apparatus, and when a can body drain plug is leaking, the drain of the water heater can be quickly and reliably detected during the hot water supply operation. A plug leak detecting device is provided.

[0005]

In order to achieve the above object, a drain plug leak detecting device of a water heater according to the present invention heats water entering from a water inlet pipe through an instantaneous heat exchange can body with a burner and supplies the water to a hot water outlet pipe. A drainage leak detecting device for a water heater in which a water inlet flow sensor is provided in the middle of the water inlet pipe and a can drain plug is provided at a downstream position thereof, wherein the water inlet flow sensor is provided. While detecting the minimum working water amount or more, if the input flow sensor provided in the water inlet pipe detects a sudden change in the input water flow more than a certain number of times, the combustion is temporarily stopped, and after a certain period of time, the combustion is restarted. In this case, a controller is provided which determines that there is a leak in the can body drain plug when the repetition of the combustion stoppage and the resumption of the combustion due to the rapid change of the incoming water flow rate occurs continuously for a fixed number of times.

[0006]

According to the above-mentioned feature of the present invention, when the hot water supply operation switch is turned on and the incoming water flow rate of the incoming water flow rate sensor is equal to or greater than the minimum operating water amount, all of the incoming flow rate flows to the instantaneous heat exchange can. On the premise, the required amount of combustion heat in the instantaneous heat exchange can is calculated, and the combustion by the burner is started. During the combustion, the controller monitors the incoming water flow rate detected by the incoming water flow rate sensor, and if a sudden change in the incoming water flow rate is detected for a certain number of times or more, the burner combustion is temporarily stopped. After the combustion is stopped for a certain time, the combustion is started again. The controller monitors the number of times the combustion is stopped due to the sudden change in the incoming water flow rate. If the stoppage of the combustion due to the sudden change in the incoming water flow rate occurs continuously for a certain number of times, it is determined that there is a leak in the can drain plug. If the can body drain plug is leaking, the flow passing through the incoming water flow rate sensor leaks from the can body drain plug, so that the flow rate flowing to the instantaneous heat exchange can becomes small and the temperature rises to a high temperature, causing boiling. When the temperature becomes high enough to cause boiling, the pressure of the flowing water flowing in the pipe tends to fluctuate, and the flow rate of the incoming water changes rapidly. In the present invention, the rapid change of the incoming water flow rate is detected, whereby the high-temperature boiling state in the instantaneous heat exchange can is detected, and the leakage of the can body drain plug is detected. Further, the stop of combustion for a certain period of time before the restart of combustion is a time necessary for lowering the tapping temperature to a temperature at which the water flow does not suddenly change. By once returning the flowing water state to a normal state in which the water flow does not suddenly change and rechecking, it is possible to more reliably determine the presence or absence of leakage of the can body drain plug. In the present invention, the rapid change of the incoming water flow rate is detected, whereby the high-temperature boiling state in the instantaneous heat exchange can is detected, and the leakage of the can body drain plug is detected. Since a sudden change in the incoming water flow rate detected by the incoming water flow rate sensor is detected and the leakage of the can body drain plug is determined, it is relatively early before the time when the instantaneous heat exchange can body is damaged by heat is elapsed. In addition, it is possible to relatively quickly detect leakage of the can body drain plug. The judgment is
Since the determination is made by repeating the combustion stoppage caused by the sudden change of the incoming water flow multiple times, the temporary stoppage due to the temporary boiling of the hot water in the outlet pipe due to the post-boil after the stop of hot water supply, and other temporary stoppages A sudden change in water flow can be excluded, and leakage of the can body drain plug can be reliably detected. Further, by stopping the combustion once due to the rapid change of the incoming water flow rate a plurality of times, the overheated state of the instantaneous heat exchange can can be cooled, and the overheated state can be prevented from continuing for a long time.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
FIG. 1 is an overall configuration diagram of a water heater provided with the apparatus of the present invention, FIG.
5 is a flowchart illustrating a drainage plug leak detection mechanism by the controller.

First, the water heater shown in FIG. 1 will be described. This water heater also has a facility for hot water reheating, and in addition to the instantaneous heat exchange can body 10 for hot water supply, an instantaneous heat exchanger 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 is omitted. The water heater includes the instantaneous heat exchange can body 10, a water inlet pipe 11 for sending water thereto, a hot water pipe 12 for tapping hot water heated by the heat exchange can body 10, and a hot water pipe 12 from the water inlet pipe 11. A bypass pipe 13 for bypassing the water, a mixing controller 14 for mixing and adjusting the water from the bypass pipe 13 and the hot water from the tapping pipe 12, and a hot water supply connected downstream of the mixing controller 14. And a tube 15.

The instant heat exchanger body 10 is heated by a burner 16 such as a petroleum burner. The can 10 is provided with a can temperature fuse 17. The water inlet pipe 11 is provided with a water flow sensor 21 and a water temperature sensor 22. The drain pipe 18 is located downstream of the inlet flow rate sensor 21 of the inlet 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 tapping pipe 12 is provided with a tapping 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. Reference numeral 30 denotes a controller. The controller 30 controls the entire apparatus, and includes an incoming water flow rate sensor 21, an incoming water temperature sensor 22, an outgoing water temperature sensor 23,
Inputs information from the hot water supply temperature sensor 24 and other sensors, and also inputs set hot water supply temperature information by a remote controller (not shown), performs necessary calculations, and issues necessary commands to the burner 16 and the can body drain plug 19. , Send to others.

In the above-mentioned water heater, when the hot water supply operation switch of the apparatus is turned on, the hot water supply curl (not shown) is opened or the can body drain plug 19 is leaked.
When a flow rate equal to or more than the minimum working water flow rate (MOQ) flows into the incoming water flow rate sensor 21, the combustion operation is started regardless of whether or not the hot water supply curn is opened. As a normal operation, hot water is supplied from the water inlet pipe 11 through the heat exchange can body 10 to the hot water outlet pipe 12, and water from the bypass pipe 13 is appropriately supplied to the hot water from the hot water pipe 12 by the mixing controller 14. The hot water that has been adjusted and adjusted to the set hot water supply temperature flows to the hot water supply pipe 15. The can body drain plug 19 can be opened and closed automatically and manually by the controller 30 as necessary. By opening the can drain plug 19, the residual water in the instantaneous heat exchange can 10 can be discharged. Meanwhile, this can body drain plug
If 19 is broken during hot water supply operation or is open due to other causes, part of the incoming water is discharged from the can body drainage plug 19 without flowing to the instantaneous heat exchange can body 10, so the instantaneous heat The hot water from the exchange can body 10 becomes extremely hot, causing a problem of boiling.

A mechanism for detecting leakage of the can body drain plug 19 by the controller 30 will be described with reference to FIG. Now, when the hot water supply operation switch is ON (YES in S1), the hot water supply end of the hot water supply pipe 15 (not shown) is opened, or the can body drain plug 19 is leaking, so that the input water flow sensor 21 detects the minimum operating water amount. If (MOQ) or more is detected (Yes in S2), combustion is started (S3). The controller 30 includes a set hot water supply temperature set by a remote controller or the like (not shown), an incoming water temperature detected by the incoming water temperature sensor 22, a flow rate detected by the incoming water flow rate sensor 21, and an initial distribution ratio of the mixing controller 14. For example, the required amount of combustion heat required to supply the hot water at the set hot water supply temperature to the hot water supply pipe 15 is calculated, and the burner 16 is burned so as to output the required amount of combustion heat.

During the combustion operation, the controller 30 monitors the incoming water flow rate detected by the incoming water flow rate sensor 21 provided in the water inlet pipe 11, and detects a sudden change in the incoming water flow rate (yes in S4). One of the counters is used as a sudden change counter for counting the number of sudden changes in the flow rate, and 1 is added to the sudden change counter (S5). Yes), stop the combustion for a certain time (S
7). The sudden change in the incoming water flow rate can be set as an abrupt change in the incoming water flow rate, for example, when there is a change of a certain or more flow rate within a unit time. In this case, the flow rate exceeding a certain value per unit time can be determined by experimentally obtaining the flow rate in advance according to the scale of the water heater or the instantaneous heat exchange can. In addition, the total number of sudden changes for temporarily stopping combustion is the number of times that it can be determined that the temperature of the tap water is high enough to boil, and this is also the number of water heaters and instantaneous heat exchange cans. It can be determined experimentally according to the scale and the like. In this embodiment, the number of times is six. By making the number of sudden changes in the flow rate a plurality of times, due to the temporary boiling of hot water in the tapping pipe 12 due to post-boil after hot water supply,
Other temporary changes in water flow can be excluded. In addition, the fixed time for stopping the combustion is such that the instantaneous heat exchange can body 10 is cooled so as not to be damaged after the lapse of the fixed time, and the tapping temperature is reduced, thereby causing a large pressure on the flowing water flowing in the pipe. This time is the time required to prevent fluctuations, and this constant time can also be obtained experimentally. In the embodiment, the time is one minute, but it can be several tens of seconds to several minutes depending on the scale of the water heater or the instantaneous heat exchange can.

When the controller 30 stops the combustion for a certain period of time due to the sudden change in the flow rate (S7), one of the built-in counters is used as a stop counter for counting the stop of combustion, and 1 is added to the stop counter (S8). When the number of times is equal to or more than a certain number, that is, when the total of the stop counter is equal to or more than a certain
9), the controller 30 determines that there is a leak from the can drain plug 19 (S10), and displays a leak of the can drain plug 19 on a remote control (not shown) or the like, and performs a safe operation of the water heater. S11). The safe operation is to completely stop the combustion operation of the burner 16, for example. The certain number of times can be set to several times in order to increase the certainty of the determination. However, in this embodiment, it is set to twice.

[0014]

According to the present invention, there is provided the above construction.
According to the water heater drain plug leak detection device described in (1), a sudden change in the incoming water flow rate detected by the incoming water flow sensor is determined to determine the leakage of the can body drain plug, so that the instantaneous heat exchange can body is thermally damaged. It is possible to relatively quickly detect the leakage of the can body drain plug before the elapse of such time. In addition, since the determination is made by repeating a plurality of times of stopping the combustion due to a plurality of sudden changes in the incoming water flow rate, it is based on a temporary boiling of hot water in the tapping pipe due to a post-boil after the stop of hot water supply, Other temporary changes in the water flow can be eliminated, and leakage of the can body drain plug can be reliably detected. In addition, the combustion is stopped for a certain period of time each time a sudden change in the incoming water flow occurs a certain number of times, thereby cooling the overheated state of the instantaneous heat exchange can, etc., and effectively preventing damage to the can, etc. Can be prevented.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a water heater provided with the apparatus 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 exchanger body 11 Water inlet pipe 12 Hot water pipe 13 Bypass pipe 14 Mixing regulator 15 Hot water supply pipe 16 Burner 18 Drain pipe 19 Can body drain plug 21 Water flow sensor 22 Water temperature sensor 23 Hot water temperature sensor 24 Hot water temperature sensor 30 controller

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kimiaki Asano 32nd Akashi-cho, Chuo-ku, Kobe-shi, Hyogo Noritsu Co., Ltd. (56) References JP-A-6-26706 (JP, A) Japanese Utility Model 5-47744 (JP, U)

Claims (1)

(57) [Claims] The present invention is characterized in that water entering from a water inlet pipe is heated by a burner through an instantaneous heat exchange can body and discharged to a hot water outlet pipe, and an incoming water flow rate sensor is provided in the middle of the water inlet pipe and at a downstream position thereof. A drain plug leak detection device in a water heater provided with a can body drain plug, wherein the input water flow sensor provided in the water inlet pipe receives water when the input water flow sensor detects a minimum operating water amount or more. If a sudden change in the flow rate is detected for a certain number of times or more, the combustion is temporarily stopped, and after stopping for a certain period of time, the combustion is restarted. In this case, there is provided a controller for judging that the can body drain plug has a leak.