JP3901308B2 - Residual water confirmation device and residual water confirmation method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a residual water confirmation device and a residual water confirmation method for detecting whether or not there is water supply in a hot water supply pipe passing through a heat exchanger.
[0002]
[Prior art]
In order to improve the comfort of hot water heaters that have been used in the past, in order to provide hot water at almost the set temperature from the beginning of the hot water, in preparation for the next hot water, there is no water in the heat exchanger. Some have a function of keeping hot water in a predetermined temperature range. In normal hot water, the burner is ignited after detection of water flow, whereas in the heat insulation operation described above, ignition is performed in the absence of water flow. May cause.
[0003]
Conventionally, in order to prevent such an airing, the presence / absence of water supply is determined based on the results in the hot water performed before ignition by the heat retaining operation. That is, based on the history of the fact that the flow sensor operated normally in the previous hot water discharge and no emptying occurred, it is estimated that the hot water supply pipe is currently filled with water, and the burner based on the heat retaining operation I was igniting.
[0004]
[Problems to be solved by the invention]
However, in such a conventional technique, the presence or absence of water supply is determined based on the results of the previous hot water discharge, so if the water is drained for maintenance or freezing prevention, the hot water is then discharged. In the meantime, it was not possible to determine the presence or absence of water supply, and there was a possibility of causing emptying.
[0005]
The present invention has been made paying attention to such problems of the conventional technology, and a remaining water confirmation device and a remaining water confirmation device that can easily and quickly detect whether or not water supply exists in a hot water supply pipe. The purpose is to provide a water confirmation method.
[0006]
[Means for Solving the Problems]
The gist of the present invention for achieving the object lies in the inventions of the following items.
[1] In a residual water confirmation device that detects whether there is water in the hot water pipe (21) that passes through the heat exchanger (13),
A plurality of electrodes (29, 21) arranged in the hot water supply pipe (21), and continuity inspection means (53) for inspecting whether there is continuity between the electrodes (29, 21),
The presence or absence of conduction between the electrodes (29, 21) is detected by the conduction inspection means (53) to detect whether there is water in the hot water supply pipe (21) ,
A temperature sensor (29) for detecting the water temperature in the hot water supply pipe (21), at least the tip (29a) of which is covered with a conductive member, the tip (29a) is connected to the hot water pipe ( 21) Arrange it so that it is exposed inside,
Further, the temperature sensor (29) is provided with a water-repellent coating except for the tip portion (29a), and is provided on the upper side of the hot water supply pipe (21), and the tip portion (29a) is directed downward from the upper side to drop water drops. Arrange to reduce adhesion,
The residual water confirmation apparatus characterized by using the electroconductive member which the said temperature sensor (29) has as one of the said electrodes (29, 21) .
[0008]
[ 2 ] A water heater (10) having a function of burning the burner (12) in a state where there is no water flow and keeping the water supply in the heat exchanger (13) within a predetermined temperature range in preparation for the next hot water. It is used, and at least when the water heater (10) burns the burner (12) in a state where there is no water flow, it is detected whether or not there is water supply in the hot water supply pipe (21). 1] The residual water confirmation apparatus.
[0009]
[ 3 ] The hot water supply pipe (21) is formed of a conductive member, and the hot water supply pipe (21) is used as one of the electrodes (29, 21) [1] or [2] residual water confirmation device according to.
[0010]
[ 4 ] Disposing at least one of the electrodes (29, 21) for checking the presence or absence of conduction by the continuity checking means (53) at a location where water is exhausted at an initial stage when water in the hot water supply channel starts to escape. The residual water confirmation device according to [1], [2] or [3], which is characterized.
[0011]
[ 5 ] The continuity inspection means (53) arranges the electrode (29) for inspecting the presence / absence of continuity in a place where water is exhausted when almost all of the water in the hot water supply passage is removed [1], [2], [3] or [4] .
[0012]
[ 6 ] [1], [2], [3], [4] or [5], wherein the electrode (29) is covered with a water-repellent film except for its tip (29a). Residual water confirmation device.
[0013]
[ 7 ] The residual water confirmation apparatus according to [6], wherein the water-repellent film is an insulating film having an insulating property.
[0014]
[ 8 ] The continuity checking means (53) applies a predetermined voltage between the electrodes (29, 21) only when checking whether or not there is water in the hot water pipe (21). The remaining water confirmation device according to [1], [2], [3], [4], [5], [6] or [7] .
[0015]
[ 9 ] [1], [2], [3], [4], [5], [6], [7] or [8] is passed through the heat exchanger (13) by the residual water confirmation device. residual water confirmation method characterized by detecting whether there is a water supply to the hot water pipe (21).
[0016]
The present invention operates as follows.
A plurality of electrodes (29, 21) are arranged in the hot water supply pipe (21), and it is detected whether there is water supply in the hot water supply pipe (21) based on the presence or absence of conduction between the electrodes (29, 21). . When there is water supply in the hot water supply pipe (21), since a slight current flows through the water supply, continuity appears between the electrodes (29, 21), and continuity does not appear when there is no water supply. Thus, since the presence or absence of water supply is determined by the presence or absence of conduction between the electrodes (29, 21), the presence or absence of water supply can be confirmed quickly and easily at any time.
[0017]
Further, a temperature sensor (29) for detecting the water temperature in the hot water supply pipe (21), at least the tip (29a) of which is covered with a conductive member, is inserted into the hot water supply pipe (21) with the tip (29a). ) Is exposed, and the conductive member of the temperature sensor (29) is also used as one of the electrodes.
[0018]
Usually, a temperature sensor (29) such as a thermistor is arranged so as to be exposed in the hot water supply pipe (21) in order to detect the hot water temperature and the feed water temperature. Further, the tip (29a) is covered with a metal (conductive member) such as stainless steel having good thermal conductivity. Therefore, by sharing this as one of the electrodes, it is not necessary to separately arrange an electrode, and the device cost can be reduced.
[0019]
In addition, the above-described residual water check device has a function of keeping the water in the heat exchanger (13) within a predetermined temperature range by burning the burner (12) in the absence of water flow and preparing the water supply in the heat exchanger (13) for the next hot water. Used in the hot water heater (10) having at least the hot water heater (10) to detect whether there is water in the hot water pipe (21) when the burner (12) is burned with no water flow. . As a result, it is possible to reliably prevent the occurrence of idling during ignition for the heat retaining operation.
[0020]
Furthermore, the hot water supply pipe (21) is usually made of a metal having good thermal conductivity. Therefore, the apparatus price can be further reduced by using the hot water supply pipe (21) as one of the electrodes.
[0021]
At least one of the electrodes (29, 21) for inspecting the presence / absence of continuity by the continuity inspection means (53) is arranged at a location where the water supply disappears at an initial stage when the water supply begins to escape. For example, one electrode (29) is arranged at the uppermost position in the route of the hot water supply pipe (21). As a result, it is possible to quickly detect missing water supply and prevent emptying. In addition, you may make it arrange | position an electrode in the location where water supply is lost when almost all the water supply has come off. In this case, it is detected that there is no water supply only when all of the water supply has been lost and airing has occurred.
[0022]
Further, the electrode (29) is covered with a water-repellent film except for the tip (29a). For example, if the hot water pipe (21) is used as one electrode and the other electrode is also used as the temperature sensor (29), the gap between the hot water pipe (21) and the tip (29a) of the temperature sensor (29) is compared. Therefore, even if the water supply is actually removed, if water droplets are attached to the temperature sensor (29) due to surface tension, conduction will occur and false detection will occur. Therefore, the temperature sensor (29) is provided with a water-repellent coating except for its tip (29a) to prevent adhesion of water droplets due to surface tension.
[0023]
The continuity checking means (53) applies a predetermined voltage between the electrodes (29, 21) only when checking whether there is water supply in the hot water supply pipe (21). As a result, electrolytic corrosion due to electrolysis does not progress so much, and the life of the electrode can be sufficiently secured. For example, a voltage may be applied between the electrodes (29, 21) to detect the presence / absence of conduction only when shifting from the state in which the heat retaining operation is not performed to the operation mode in which the heat retaining operation is performed.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
Each figure shows an embodiment of the present invention.
A water heater 10 according to the present invention has a function of supplying hot water into a faucet or a bath tub and a function of chasing hot water in the tub, and both the reheating path and the hot water supply path are provided by one heat exchanger. It is a so-called 1 can 2 water channel type that heats. As shown in FIG. 1, the water heater 10 includes a combustion chamber 11, a burner 12 is provided at the lower part of the combustion chamber 11, and heat from the burner 12 is provided at the upper part of the combustion chamber 11 for supplying water or the like. A heat exchanger 13 for transmitting is arranged.
[0025]
Both the hot water supply pipe 21 for flowing hot water and the recirculation pipe 31 for circulating water in the bathtub for reheating pass through the heat exchanger 13. The heat from the burner 12 is transmitted to the fluid in both the pipes 21 and 31 and heated.
[0026]
A fixed bypass path 22 and a flow control valve 23 are provided between a water supply side flow path 21 a of the hot water supply pipe 21 toward the heat exchanger 13 and a hot water supply side flow path 21 b after exiting the heat exchanger 13. The two bypass paths 24 are connected to each other. The hot water heated by the heat exchanger 13 is mixed with the feed water through the fixed bypass passage 22 and the bypass passage 24, and the bypass ratio can be controlled by the flow control valve 23. In addition, a flow rate control valve 25 for controlling the total flow rate of the hot water and the bypass ratio is provided on the hot water supply side channel 21b side of the hot water supply pipe 21.
[0027]
Flow sensors 26a and 26b for detecting the presence / absence of water flow and the amount of water flow are provided in the vicinity of the inlet and outlet of the hot water supply pipe 21, respectively. In addition, an incoming water thermistor 27 for detecting the temperature of the hot water supply is attached in the vicinity of the inlet portion of the hot water supply pipe 21, and an outlet hot water thermistor 28 for detecting the temperature of the hot water supply is attached in the vicinity of the outlet portion of the hot water supply pipe 21. It has been. A heat exchanger thermistor 29 for detecting the hot water temperature immediately after leaving the heat exchanger 13 is provided in the water pipe near the outlet of the heat exchanger 13.
[0028]
The heat exchanger thermistor 29 functions as an electrode for checking residual water. As shown in FIG. 2, the heat exchange thermistor 29 is attached so that the tip 29 a protrudes into the hot water supply pipe 21. The heat exchange thermistor 29 has a structure in which a thermistor element (not shown) is covered with stainless steel having conductivity, and is further covered with an insulating film 29b except for the tip portion 29a.
[0029]
Further, the heat exchange thermistor 29 is provided with a water-repellent coating except for its tip portion 29a. Therefore, the tip portion 29a is in a state where the stainless steel portion as the conductive member is exposed. From the heat exchanger thermistor 29, a lead wire 29c of the thermistor and an electrode lead wire 29d connected to the tip portion 29a (exposed stainless steel portion) are exposed. The hot water supply pipe 21 is made of a conductive metal and is used as the other electrode for checking the remaining water.
[0030]
The circulation pipe 31 for reheating is composed of a bath return pipe portion 31a for returning water in the bathtub 40 to the heat exchanger 13 and a bath return pipe portion 31b for sending hot water heated by the heat exchanger 13 to the bathtub 40. ing. In the middle of the bath return pipe portion 31a, a circulation pump 32 and a bath running water switch 33 for detecting the presence or absence of water flow in the bath return pipe portion 31a are provided. A bath temperature thermistor 34 for detecting the temperature of hot water flowing from the bathtub 40 side is attached in the vicinity of the bath water switch 33.
[0031]
The hot water supply side pipe 21b of the hot water supply pipe 21 and the bath return pipe portion 31a are connected by a pouring pipe 36 having a pouring solenoid valve 35, and the hot water supplied by the heat exchanger 13 is poured. Hot water can be poured into the bathtub 40 through the pipe 36.
[0032]
The supply / exhaust is forcibly performed by blowing the supply air from the lower side of the combustion chamber 11 by the combustion fan 14, and the exhaust is discharged from the upper part of the combustion chamber 11. An ignition device 15 is provided in the vicinity of the burner 12. The combustion gas supplied to the burner 12 is on / off controlled by the gas electromagnetic valve 16, the original gas electromagnetic valve 17, and the gas switching valve 18, and the gas amount is adjusted by the gas proportional valve 19.
[0033]
The water heater 10 includes a control board 50 as a circuit that performs various control functions, and an operation unit 60. The operation unit 60 corresponds to a so-called main remote controller or bath remote controller, and includes various operation switches and a small liquid crystal display.
[0034]
The control board 50 includes a heat retention control unit 51 and a remaining water confirmation unit 52, and the remaining water confirmation unit 52 further includes a continuity inspection unit 53. Of these, the heat retention control unit 51 is a circuit portion that performs the function of igniting the burner 12 in a state where there is no water flow and keeping the hot water in the heat exchanger 13 within a predetermined temperature range. The remaining water confirmation unit 52 is a circuit portion that determines whether or not water supply exists in the hot water supply pipe 21 based on the presence or absence of conduction between two electrodes including the heat exchange thermistor 29 and the hot water supply pipe 21. is there. The continuity inspection unit 53 included in the remaining water confirmation unit 52 is a circuit portion that applies a predetermined voltage between electrodes including the hot water supply pipe 21 and the heat exchange thermistor 29.
[0035]
More specifically, the control board 50 executes a central processing unit (CPU) that performs a central function of various controls, a ROM that stores programs executed by the CPU and various fixed data, and programs. It is composed of a circuit having a main part of a RAM for storing temporarily necessary data.
[0036]
Here, the heat exchanger thermistor 29 and the hot water supply pipe 21 are used as electrodes. However, as shown in FIG. 3, two electrodes 71a and 71b with their tips exposed are provided separately in the hot water supply pipe 21. It may be. These electrodes 71a and 71b are held via an insulating portion 72 so as not to directly contact the hot water supply pipe 21.
[0037]
Next, the operation will be described.
While the heat retaining function is on, the water heater 10 burns the burner 12 in a state where it is not opened so that hot water at a set temperature is discharged immediately after opening, and the hot water temperature in the heat exchanger 13 is increased. A heat retention operation is performed to keep the temperature within a predetermined temperature range. Such a heat retaining function can be sequentially turned on / off via the operation unit 60, and an operation time can be set in advance from 7 am to 7 pm. Furthermore, it is possible to set the heat retaining function to operate only for 5 minutes after the previous hot water supply is stopped. The hot water in the heat exchanger 13 is kept warm by repeatedly burning the burner 12 for about 1 to 2 seconds at intervals of 1 to several minutes.
[0038]
Here, the residual water check is performed when the heat retaining function shifts from the off state to the on state. As shown in FIG. 4, when the heat retention function shifts from the off state to the on state, such as when the operation switch is turned on first in the morning (step S <b>101; Y), the continuity inspection unit 53 is the tip of the heat exchanger thermistor 29. A predetermined voltage is applied between the two electrodes composed of 29a and the hot water supply pipe 21 (step S102).
[0039]
At this time, the remaining water confirmation unit 52 checks whether or not there is current between the electrodes (step S103), and if there is current (step S103; Y), determines that there is water supply in the hot water supply pipe 21. When the water supply is confirmed, the heat retention control unit 51 ignites the burner 12 and heats the water temperature in the heat exchanger 13 to the target temperature range to be kept warm (step S104), and enters the target temperature range. After that, the operation proceeds to a heat retention mode for maintaining the temperature (an operation mode in which the burner 12 is burned for 1 to 2 seconds at intervals of several minutes and intermittently burned) (step S105).
[0040]
On the other hand, when energization is not confirmed (step S103; N), a warning that there is no water supply is displayed on the display unit or the like of the operation unit 60 (step S106). Note that the warning need not be displayed.
[0041]
In this way, the presence / absence of water supply is determined by the presence / absence of conduction between the electrodes, so the presence / absence of water supply can be confirmed even when there is no water flow history, such as when the heat insulation function is turned on first in the morning. Can be reliably prevented.
[0042]
Further, since the voltage is applied between the electrodes only when the residual water is confirmed, the progress of corrosion of the electrodes due to electrolysis is small, and the life of the electrodes can be sufficiently secured. Furthermore, since the heat exchanger thermistor 29 is also used as one of the electrodes and the hot water supply pipe 21 is used as the other electrode, the apparatus cost can be reduced as compared with a case where an electrode is separately provided.
[0043]
In addition, since the heat exchange thermistor 29 of the two electrodes is attached to the uppermost portion of the hot water supply pipe 21, it is possible to quickly detect the loss of the water supply in the hot water supply pipe 21. it can. In addition, when the electrode is arranged at a place where the water supply disappears when almost all of the water supply in the hot water supply pipe 21 has been removed, it is detected that there is no water supply only when all the water supply has been removed and there is a possibility of watering. Is done. For example, if one electrode is attached to a place where the water-filling thermistor 27 is located in FIG. 1, the continuity is lost when almost all of the water supply is lost, and it is detected that there is no water supply.
[0044]
The heat exchanger thermistor 29 also serving as an electrode is provided with a water-repellent coating except for a tip portion 29a that functions as an electrode. For this reason, the adhesion of water droplets due to surface tension is reduced, water droplets remain between the hot water supply pipe 21 and the tip portion 29a of the heat exchanger thermistor 29. It is possible to prevent the detection from occurring.
[0045]
In addition, as shown in FIG. 2, the heat exchange thermistor 29 is provided on the upper side of the hot water supply pipe 21, and the tip 29 a is arranged downward from the upper side to further reduce the adhesion of water droplets.
[0046]
In the embodiment described above, the heat exchanger thermistor 29 and the hot water supply pipe 21 are also used as electrodes, but each electrode may be provided separately.
[0047]
【The invention's effect】
According to the residual water confirmation device and the residual water confirmation method according to the present invention, since a plurality of electrodes are arranged in the hot water supply pipe and the presence or absence of water supply is detected based on whether or not there is conduction between these electrodes, Can be confirmed quickly and easily at any time.
[0048]
Moreover, since the temperature sensor for detecting the water temperature in the hot water supply pipe is usually covered with a metal having good thermal conductivity, it is necessary to install another electrode by using it as one of the electrodes. Therefore, the device price can be reduced. Furthermore, since the hot water supply pipe is usually made of a metal having good thermal conductivity, the use of this as one electrode can further reduce the cost of the apparatus.
[0049]
In addition, since a predetermined voltage is applied between the electrodes only when it is confirmed whether or not there is water supply in the hot water supply pipe, there is little corrosion of the electrodes due to electrolysis, and a sufficient life can be ensured.
Et al is, together with the tip portion at least in the tip portion is coated with a conductive member to a temperature sensor for detecting the temperature of the hot water pipe is disposed so as to be exposed to the hot water pipe The temperature sensor is provided with a water-repellent coating except for the tip portion, and is provided on the upper side of the hot water pipe, and the tip portion is arranged so as to reduce the adhesion of water droplets from the upper side to the lower side. Can prevent false detection.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a water heater to which a residual water confirmation device according to an embodiment of the present invention is applied.
FIG. 2 is an explanatory view showing a mounting state of a temperature sensor also used as an electrode.
FIG. 3 is an explanatory diagram showing an example of a state in which two electrodes are provided independently.
FIG. 4 is a flowchart showing a flow of an operation performed by a water heater to which a residual water confirmation device according to an embodiment of the present invention is applied.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Hot water heater 12 ... Burner 13 ... Heat exchanger 21 ... Hot water supply pipe 26a, 26b ... Flow sensor 27 ... Incoming thermistor 28 ... Outlet thermistor 29 ... Heat exchanger thermistor 29a ... Conductive tip 29b ... Film 29c ... Thermistor Lead wire 29d ... Electrode lead wire 50 ... Control base 51 ... Insulation control unit 52 ... Residual water confirmation unit 53 ... Continuity inspection unit 60 ... Operation unit 71a, 71b ... Electrode 72 ... Insulation unit

Claims (9)

In the residual water confirmation device that detects whether there is water in the hot water pipe that passes through the heat exchanger,
A plurality of electrodes arranged in the hot water pipe, and continuity inspection means for inspecting whether there is continuity between the electrodes,
Detecting whether or not there is water supply in the hot water pipe by inspecting the presence or absence of conduction between the electrodes with the continuity inspection means ;
A temperature sensor for detecting the water temperature in the hot water supply pipe, at least the tip of which is covered with a conductive member, is arranged so that the tip is exposed in the hot water supply pipe,
Furthermore, the temperature sensor is provided with a water-repellent coating except for the tip portion, and is provided on the upper side of the hot water pipe, and the tip portion is arranged so as to reduce the adhesion of water drops downward from the upper side,
The residual water confirmation apparatus characterized in that the conductive member of the temperature sensor is also used as one of the electrodes .   Used in a water heater having a function of burning the burner in a state where there is no water flow and keeping the water supply in the heat exchanger within a predetermined temperature range in preparation for the next hot water, and at least the water heater does not pass water The residual water confirmation device according to claim 1, wherein when the burner is burned in a state, it is detected whether or not there is water supply in the hot water supply pipe. The said hot water supply pipe is formed with the electroconductive member, The said hot water supply pipe is used as one of the said electrodes, The residual water confirmation apparatus of Claim 1 or 2 characterized by the above-mentioned. To claim 1, 2 or 3, characterized in that arranged at a position eliminating the water at the initial stage of the at least one of water in the hot-water supply path began omission of the electrodes, wherein the electrical connection test means for checking the presence or absence of continuity The remaining water confirmation device described. Residue according to claim 1, 2, 3 or 4, characterized in that arranged in place water to eliminate the water phase is exited almost all of the electrodes hot water supply path in which the continuity testing means for testing whether the conduction Water confirmation device. Residual water checking apparatus according to claim 1, 2, 3, 4 or 5, characterized in that covering the electrode with a film of water-repellent except for its tip.   The residual water confirmation apparatus according to claim 6, wherein the water-repellent film is an insulating film having an insulating property. The said continuity test | inspection means applies a predetermined voltage between the said electrodes only when confirming whether there is any water supply in the said hot-water supply pipe, The 1, 2, 3, 4, 5, 6 characterized by the above-mentioned. Or the residual water confirmation apparatus of 7 . Residue, wherein the detecting whether there is a water supply to the hot water pipe through the heat exchanger by the residual water checking apparatus according to claim 7 or 8 Water confirmation method.

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