JP2616437B2 - 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 provided with an instantaneous heat exchange can body, for draining the instantaneous heat exchange can body in view of layout, prevention of freezing in winter, and the like. 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 turned on, or the hot water supply cull is opened and the hot water supply is used, and the incoming water flow sensor detects the minimum operating water amount or more, the controller starts the previous operation. Assuming that all the flow rates detected by the entry water flow rate sensor pass through the instantaneous heat exchange can body, the required amount of combustion heat of the burner is calculated, and combustion is started. However, when all the water flowing through the water inlet pipe flows out of the can body drain plug and does not flow into the instantaneous heat exchange can body, the instantaneous heat exchange can body becomes empty-fired and the can body There has been a problem that abnormal combustion such as melting of the thermal fuse or melting of the body wall of the instantaneous heat exchange can is caused.

Therefore, the present invention solves the above-mentioned drawbacks of the conventional apparatus, and when a can body drain plug is leaking, it can quickly and reliably detect the leak from the can plug. The purpose is to provide.

[0005]

In order to achieve the above-mentioned object, a drain plug leak detecting device for a water heater according to the present invention heats water from a water inlet pipe by a burner through an instantaneous heat exchange can body and discharges the hot water to a hot water pipe. At the same time, a part of the incoming water is mixed into the hot water from a bypass pipe via a mixing controller, thereby adjusting the hot water to a set hot water temperature and supplying the hot water to the hot water pipe. A drainage plug leak detecting device in the water heater, which is provided on the way with a water inlet flow rate sensor for detecting a flow rate of water flowing into the instantaneous heat exchange can body side and a can body drain plug is provided at a downstream position thereof. The temperature detected by the hot water supply temperature sensor provided in the hot water supply pipe is lower than the lower limit temperature as the normally used hot water supply temperature during the combustion by the input water flow rate sensor detecting the minimum operating water amount or more, and 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 feature of the present invention, when the hot water supply operation switch is turned on, the water flow sensor detects that the water flow is equal to or more than the minimum working water amount due to leakage of the can body drain plug or opening of the hot water supply curan. 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 appropriately mixed with the hot water, and hot water at a predetermined set hot water supply temperature is supplied to the hot water pipe. Supplied. When combustion is started when the incoming water flow rate sensor detects the minimum operating water amount or more, the detection temperature of the hot water supply temperature sensor is monitored by the controller, and the temperature detected by the hot water supply temperature sensor is set to the normally used hot water supply temperature. If 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 state is maintained for a certain period of time, and the controller determines that there is a leak in the can body drain plug. If it is normal, start burning and after a while,
The hot water supply temperature rises above the minimum level of the normally used hot water supply temperature, and even if the set hot water supply temperature is set to a value less than the minimum level, it rises above a certain temperature more than the input water temperature for a while. Should be. Therefore, if it does not become such, it is not normal and it is determined that there is a leak in the can body drain plug. When the temperature detected by the hot water supply temperature sensor is lower than the lower limit of the normally used hot water supply temperature, the temperature rise with respect to the incoming water temperature is also less than a certain value, and the state continues for a certain period of time, the water is discharged from the can body. Since it is determined that there is a leak from the plug, it is possible to relatively quickly and early detect the leak from the can body drain plug before the instantaneous heat exchange can is thermally damaged due to empty heating. The determination uses only the temperature detected by the hot water supply temperature sensor and the duration thereof as the determination items. Since the flow rate element is not included, a relatively simple leak determination mechanism and less erroneous detection can be performed. During the combustion, it is constantly monitored.For example, even if both the hot water supply and the can drain are open, it is considered normal, but when the hot water is closed, the leakage of the can drain at that point Can be detected. In addition, since the judgment is made when the constant temperature condition continues for a certain period of time, erroneous detection due to temporary hot water supply due to boiling after re-heating is eliminated, and leakage of the can body drain plug is ensured. Can be detected.

[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 water heater, when the hot water supply switch (not shown) is opened as a normal operation in a state where the hot water supply operation switch of the apparatus is on, the incoming water flow sensor 21 is turned on.
The combustion operation is started when a flow rate equal to or more than the minimum working water amount (MOQ) flows. Hot water is supplied from the water inlet pipe 11 through the heat exchange can body 10 to the hot water pipe 12, and the water from the bypass pipe 13 is appropriately adjusted by the mixing controller 14 for the hot water from the hot water pipe 12, and the setting is performed. The hot water adjusted to the 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 drainage plug 19, it is possible to prevent freezing in winter and to discharge residual water in the instantaneous heat exchange can 10 when necessary. On the other hand, when the can body drain plug 19 is open due to failure or other causes, water leaks from the can drain plug 19, and when the leak amount is equal to or more than the minimum working water amount (MOQ), Even if the hot water supply operation switch is only turned on, combustion of the burner is started even in a state where the hot water supply curan is not yet opened, and combustion continues without stopping even if the hot water supply callan is closed from the open state, Abnormal combustion occurs.

[0011] The above abnormal combustion is prevented from continuing,
A mechanism for detecting leakage of the can body drain plug 19 by the controller 30 before the can body temperature fuse blows 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 equal to or more than the minimum working water amount flows through the water inlet pipe 11, the water flow sensor 21 detects the water flow equal to or more than the minimum working water amount (MOQ). If the burner 16 is turned on to start combustion, the burner 16 starts burning if the incoming water flow sensor 21 actually detects the minimum operating water amount (MOQ) or more (YES in S2) (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 temperature detected by the hot water temperature sensor 24 is higher than the incoming water temperature detected by the incoming water temperature sensor 22 by 10 ° C. or more (S4).
It is determined whether or not the hot water supply temperature is 30 ° C. or higher (S5), and if none of the conditions is satisfied (No in S4, No in S5), it is further monitored whether the state continues for 18 seconds. (S6) If it has continued for 18 seconds or more (YES in S6), the controller 30 determines whether the can body drain plug 19 has leaked and instructs a safe operation (S7).

In step S4, 10 ° C. in the case where the hot water temperature is higher than the incoming water temperature detected by the incoming water temperature sensor 22 by 10 ° C. or more is not limited to this value. Even if the detected hot water temperature is lower than 30 ° C, there is sufficient evidence that the incoming water has been heated through the instantaneous heat exchange can if there is a significant rise in the incoming water temperature. Therefore, as the rising temperature that can be such evidence, even if it is other than 10 ° C, for example, appropriately select and set a temperature of about 5 ° C to 15 ° C according to the shape and size of the water heater Can be. Also, in the step S5, 30 ° C. in the case where the hot water supply temperature is 30 ° C. or more is not limited to this value. The above-mentioned 30 ° C. has a meaning as a lower limit temperature of 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
The temperature can be set by appropriately selecting a value in the range of 30 ° C. to 30 ° C.
Further, in the above step S6, the 18 seconds of whether or not 18 seconds have been continued are not limited to this. This 18 seconds
The fact that the constant temperature condition determined to be NO in steps S4 and S5 is continued for a fixed period of time has a meaning to eliminate erroneous determination due to temporary hot water supply due to post-boiling at the time of re-hot water supply. Things. The duration can be set by appropriately selecting a time between about 10 seconds and about 30 seconds, for example, 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 incoming water flow rate detected by the incoming water flow rate sensor 21 is less than a certain value can be added between the steps S5 and S6. In other words, if the incoming water flow rate increases significantly on the way, the hot water supply temperature may continue to be low without increasing sufficiently, but it is meaningful to eliminate such a case and make a more reliable determination. . But,
It is necessary to constantly monitor the flow rate change, and the mechanism is not simple.

[0015]

According to the present invention, there is provided the above construction.
According to the hot water supply drain tap leakage detection device described in the above, the temperature detected by the hot water supply temperature sensor provided in the hot water supply pipe during the combustion by the incoming water flow rate sensor detecting the minimum operating water amount or more, and the hot water supply water normally used It is judged that water is leaking from the can body drain plug by determining that the temperature is lower than the lower limit temperature as the temperature and the temperature rise with respect to the incoming water temperature is also less than the fixed time for a certain period of time. Before the heat exchange can is damaged by heat, the leak of the can drainage plug can be detected relatively quickly and early. The determination uses only the temperature detected by the hot water supply temperature sensor and the duration thereof as the determination items. Since the flow rate element is not included, a relatively simple leak determination mechanism and less erroneous detection can be performed. During the combustion, it is constantly monitored.For example, even if both the hot water supply and the can drain are open, it is considered normal, but when the hot water is closed, the leakage of the can drain at that point 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 re-hot water supply is eliminated,
Leakage of the can body drain plug can be reliably detected.

[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 Signs] 10 Instantaneous heat exchange can body 11 Water inlet pipe 12 Hot water pipe 13 Bypass pipe 14 Mixing controller 15 Hot water supply pipe 16 Burner 18 Drain pipe 19 Can body drain plug 21 Water flow sensor 22 Water temperature sensor 23 Water temperature sensor 24 Hot water supply temperature sensor 30 Controller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location F24H 9/16 F24H 9/16 A (72) Inventor Nobuyuki Emoto 32 Akashi-cho, Chuo-ku, Kobe-shi, Hyogo Prefecture Address Noritsu Co., Ltd. (56) References JP-A-6-26706 (JP, A) JP-A-4-344064 (JP, A)

Claims (1)

(57) [Claims] 1. An inflow water from a water inlet pipe is heated by a burner through an instantaneous heat exchange can body and heated to a hot water outlet pipe, and a part of the water input is mixed with the hot water from a bypass pipe via a mixing controller, In this way, the hot water is adjusted to the set hot water supply temperature and supplied to the hot water supply pipe. In the middle of the water supply pipe, an incoming water flow rate sensor for detecting the flow rate of incoming water flowing to the instantaneous heat exchange can body side. A drain plug leak detecting device in a water heater in which a can body drain plug is provided at a downstream position thereof, wherein the incoming water flow rate sensor detects a minimum operating water amount or more and is provided in a hot water supply pipe during combustion. When the temperature detected by the supplied hot water supply temperature sensor is lower than the lower limit temperature as the normally used hot water supply temperature, and the temperature rise with respect to the incoming water temperature is also less than a constant for a certain period of time, the can body A drain plug leak detection device for a water heater, comprising a controller that determines that the drain plug has a leak.