JP2002081756A - Hot water supplier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water supplier which can prevent the drop of accu racy in detection of water level of a tank in the case where a water level detecting electrode is used or the malfunction, while suppressing the occurrence of corrosion caused by the electrolytic corrosion of a tank, an inner pipe, etc. SOLUTION: A hot water supplier has a tank 2 which reserves hot water such as circulating water or the like and water level detecting electrodes 41 and 42 which are provided in this tank 2 and detect the existence of hot water in the tank 2, and this is equipped with a control means 33 which applies voltage higher than the voltage applied usually, to the water level detecting electrodes 41 and 42 for a predetermined time, at start of operation of itself, or in every specified period, or when the temperature of the hot water detected by a temperature sensor 25 drops to a specified temperature or under.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply apparatus for supplying hot water such as a heat source unit for hot water heating or a hot water supply boiler.
In particular, the present invention relates to a hot water supply device provided with a water level detecting device for detecting the presence of hot water such as circulating water stored in a tank using a water level detecting electrode.

[0002]

2. Description of the Related Art Conventionally, a water level detecting device of this kind of hot water supply device has a water level detecting electrode made of, for example, titanium or the like disposed in a tank, and a voltage is applied between the electrode and a conductive tank. An energizing circuit to be applied is provided, and the presence or absence and level of the circulating water in the tank are detected by detecting whether a current flows through the electrode, the circulating water, and the tank in the energizing circuit.

[0003]

By the way, in the above-mentioned water level detecting device, when an impurity dissolved in the circulating water adheres to the electrode, the impurity forms an insulating film on the surface of the electrode. In order to prevent the flow, a problem has occurred in that no current flows between the electrode and the tank even though the electrode is in contact with the liquid in the tank.

Further, even if some impurities adhere to the water level detecting electrode, for example, an applied voltage applied between the electrode and the tank is set so that a current flows and the presence of the liquid can be detected. If it raises, there is a concern that the copper pipes constituting the tank and the internal piping may be corroded and corroded.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and it is possible to suppress the occurrence of corrosion due to electrolytic corrosion of a storage tank or the like and to reduce the water level detection accuracy of the storage tank when a water level detection electrode is used. It is an object of the present invention to provide a hot water supply device capable of preventing a malfunction.

[0006]

In order to achieve the above-mentioned object, a first aspect of the present invention is a tank for storing hot water such as circulating water, and a water level detecting device provided in the tank for detecting the presence or absence of hot water in the tank. And a control means for applying a voltage higher than a voltage normally applied to the water level detection electrode to the water level detection electrode for a predetermined time when the operation of the hot water supply device is started.

According to a second aspect of the present invention, there is provided a tank for storing hot and cold water such as circulating water, and a water level detecting electrode provided in the tank for detecting the presence or absence of hot water in the tank. Control means for applying a voltage higher than the voltage to be applied every predetermined period.

According to a third aspect of the present invention, there is provided a tank for storing hot water such as circulating water, a temperature sensor for detecting a temperature of the hot water,
A water level detection electrode provided in the tank to detect the presence or absence of hot water in the tank, and when the temperature sensor detects that the temperature of hot water has dropped below a predetermined temperature,
And a control unit for applying a voltage higher than a voltage normally applied to the water level detection electrode.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a heat source unit for hot water heating according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a heat source unit of the hot water heater, and the heat source unit 1 is made of a conductive material such as copper. A storage tank 2 is provided. The storage tank 2 is connected to an internal pipe 3 made of a copper pipe including a forward path 3a and a return path 3b, and hot water such as circulating water stored in the storage tank 2 is supplied to a circulating pump 4 Is driven to circulate and supply to an external load 31 such as a hot water air conditioner indoor unit.

[0010] The circulating pump 4 is provided in the forward path 3a, a forward header 5 with a thermal valve is provided at a downstream end of the forward path 3a, and circulating water is provided in the middle of the forward path 3a. A heat exchanger 6 for raising the temperature of the heat exchanger 6 is provided.
An inlet-side temperature sensor 25 and an outlet-side temperature sensor 26 for detecting the temperatures of the circulating water on the inlet side and the outlet side, respectively, are attached.

A gas burner 7 is provided below the heat exchanger 6, and gas fuel is supplied to the burner 7 through a filter 8, an original gas solenoid valve 9, a gas solenoid valve 10, and a gas proportional valve 11. You.

Reference numeral 12 denotes a combustion fan for supplying combustion air to the burner 7; 13 an exhaust port for exhausting combustion exhaust gas;
Reference numeral 4 denotes a return header provided at the upstream end of the return path 3b in the internal pipe 3. Reference numeral 15 denotes a bypass pipe which connects the forward path 3a and the return path 3b of the internal pipe 3 by passing the load 31. Reference numeral 21 denotes an igniter. , 22 is a burner motor for driving the combustion fan 12, and 23 is a combustion can body provided with the heat exchanger 6. A safety device 24 for preventing overheating is provided above the can body 23.

16 is a drain tank, 17 is a water pipe, 18
Is a pressure cap provided at the upper part of the storage tank 2 and also serving as a circulating water supply port cap, and 19 is an overflow pipe provided in the drain tank 16.

Reference numeral 30 denotes a remote controller for operating a load 31 such as a radiator for floor heating. The remote controller 30 is connected to a control device 32 built in the heat source unit 1 via a communication line. A heating operation key (not shown) for instructing heating start or stop by a load 31 such as a floor heating radiator and the like, and a temperature setting key (not shown) for setting a heating target temperature, while remotely controlling a combustion operation, an operation stop, and the like. And a display (not shown) for displaying the heating target temperature.

Reference numerals 41 and 42 denote electrodes for detecting the water level provided in the storage tank 2.
Are made of a conductive metal material such as titanium. One of these water level detection electrodes 41 and 42 detects the high water level of the tank 2 and the other water level detection electrode 41 The electrode 42 detects the low water level of the tank 2.

Since the heat source unit 1 has the above configuration, the heating operation by the heat source unit 1 is as follows. First, when the circulating pump 4 is driven to rotate, the circulating water in the storage tank 2 enters the heat exchanger 6 through the circulating pump 4, where the temperature rises. Etc., and the load 3
After being radiated at 1, the heat is returned to the storage tank 2 again via the return header 14.

If the water in the storage tank 2 drops below a required level, the pressure cap 18
, Circulating water can be supplied to the storage tank 2 using a water supply pump or the like (not shown).

FIG. 2 is an explanatory diagram showing a schematic configuration of the control device 32. Next, the configuration of the control device 32 will be described. The control device 32 includes a timer, a ROM storing a control program, and a RAM storing various data.
A microcomputer 33 (hereinafter, referred to as a microcomputer) having a built-in memory and the like, and an EEPROM (not shown) as a writable storage means (not shown).

The input side of the microcomputer 33 is connected to a heating operation key (not shown), a temperature setting key (not shown), the temperature sensors 25 and 26, a frame sensor 34, and the like. The output side of 33 is connected to the circulation pump 4, the original gas solenoid valve 9, the gas solenoid valve 10, the gas proportional valve 11, the igniter 21, the burner motor 22, and the like.

The microcomputer 33 has an energizing circuit 35.
The power supply circuit 35 is connected to the water level detection electrodes 41 and 42 to constitute a water level detection device 36 for detecting the water level of the storage tank 2.

The energizing circuit 35 has an integrated circuit IC1 and applies a normal applied voltage (D) to the water level detecting electrodes 41 and 42.
C5V) and a comparator I
C2, IC4, integrated circuits IC3, IC5, a detection unit for detecting the presence or absence of circulating water based on the presence or absence of current, and a transistor Q1, and a high voltage higher than a normal applied voltage to the water level detection electrodes 41, 42. And a high voltage application section for applying a voltage (12 V DC).

Normally, the voltage applying unit receives a pulse signal output from the microcomputer 33 during operation of the heat source unit 1 and receives a pulse signal between the storage tank 2 and the water level detecting electrodes 41 and 42 via a power supply. A pulse voltage of DC 5V for ON for 0.9 seconds and OFF for 0.9 seconds is applied.

Here, when a current flows through the water level detection electrode 41 for detecting the high water level, the comparator IC2 detects the current, and the output is inverted by the integrated circuit IC3 to be output to the microcomputer 3.
3 to output a signal. Similarly, when a current flows through the water level detection electrode 42 for detecting the low water level, the comparator IC 4
Detects this, inverts the output in the integrated circuit IC5, and outputs a signal to the microcomputer 33.

The high voltage application section turns on the transistor Q1 to apply a high voltage of 12 V DC between the storage tank 2 and the water level detection electrodes 41 and 42. Thus, by applying a high voltage, the insulating films on the surfaces of the water level detection electrodes 41 and 42 caused by the adhesion of impurities in the circulating water are peeled off, and as a result, the surface of the water level detection electrodes is cleaned. It is.

In the above-described energizing circuit 35, when the microcomputer 33 outputs a pulse signal, the water level detecting electrode 4
A pulse voltage of about 5 VDC is applied to the first and the second. The water level of the circulating water in the water storage tank 2 is determined by a water level detection electrode 41,
Only when the position level exceeds the position level of 42, a current flows through the energizing circuit 35, and the current value is detected by the detection unit.
The microcomputer 33 determines that there is circulating water when the current value detected by the detection unit is equal to or greater than the threshold value, and determines that there is no circulating water when the current value detected by the detection unit is less than the threshold value. I do. Here, when the microcomputer 33 determines that there is no circulating water, the transistor Q1 is turned on, and a high voltage of DC12V is applied to the water level detection electrodes 41 and 42.

By the way, if the circulating water in the storage tank 2 reaches the tip level of each water level detecting electrode 41 during the heating operation of the heat source unit 1, the current from the power supply VDD1 is supplied to the integrated circuit IC1, the resistor T1, It flows into the storage tank 2 via the water level detection electrode 41 and the circulating water. Thus, if a current is flowing through the storage tank 2, the microcomputer 33 determines a signal input via the comparator IC2 and the integrated circuit IC3.

On the other hand, if the circulating water in the storage tank 2 does not reach the tip level of the water level detection electrode 42, no current flows, and the circulating water at a level necessary for the heating operation is not stored in the storage tank 2. Will be.

Next, the cleaning operation of the water level detecting electrode will be described with reference to the flowcharts of FIGS.

FIG. 3 is a flowchart showing a case where the water level detecting electrode is cleaned at the time of starting the heating operation in one embodiment of the present invention. In FIG. 3, first, the microcomputer 33 determines whether or not the heat source unit 1 has started the heating operation in step S1. If it is determined that the operation has been started, the microcomputer 33 sets a timer for about 10 seconds, for example (step S1). S2) Next, the transistor Q
1 is turned on, and a high voltage of DC12V is applied to the water level detection electrodes 41 and 42 for about 10 seconds (step S3) (cleaning operation of the water level detection electrode). Next, the microcomputer 33
When it is determined that the application of the high voltage to the water level detection electrodes 41 and 42 has been performed for 10 seconds, the process proceeds to step S5, the transistor Q1 is turned off, and a low voltage of DC5V is applied to the water level detection electrodes 41 and 42 to perform normal operation. Is performed. When a heating operation stop signal is input to the microcomputer 33 during the execution of the combustion operation process (step S5), the microcomputer 33 determines that the operation has been completed in step S6, and performs the combustion operation of the heat source device 1. And stop
Return to the state before step S1, and wait until the next operation start signal is input.

As described above, a high voltage (12 V DC) higher than the normal applied voltage (5 V DC) is applied to the water level detection electrodes 41 and 42 at the start of operation of the equipment, for example, for about 10 seconds, so that the water level detection electrodes 41 and 42 are applied. , 42 and the insulating film on the electrode surface can be removed or peeled off, thereby preventing the water level detection accuracy of the storage tank 2 from being lowered.

In addition, since the application of the high voltage to the water level detecting electrodes 41 and 42 is performed only for a short time of about 10 seconds each time the operation of the apparatus is started, the storage tank 2 made of a conductive material such as copper or the internal piping is used. It is possible to suppress the occurrence of electrolytic corrosion and corrosion of the copper pipe constituting 3.

FIG. 4 is a flowchart showing a case in which the water level detecting electrode is cleaned every predetermined period in another embodiment of the present invention. In FIG. 4, first, the microcomputer 33 sets the timer 1 for about 720 hours (about one month) when the power of the device is turned on, and then determines whether the timer 1 has counted up (step S12).
When the timer 1 counts up, the timer 2 for about 10 seconds is set (step S13), and then the transistor Q1 is turned on to reduce the high voltage of DC12V to about 10 seconds.
For 2 seconds, applied to the water level detection electrodes 41 and 42 (step S1).
4) Perform (cleaning operation of the water level detection electrode). When the microcomputer 33 determines that the timer 2 has counted up, the microcomputer 33 returns to the state before step 12 and again executes 720
Wait for the time to elapse.

In step S12, the heat source device 1
Is performing a normal combustion operation, the application of the high voltage to the water level detection electrodes 41 and 42 is postponed, and the application of the high voltage to the water level detection electrodes 41 and 42 after the heating operation of the heat source unit 1 is stopped. I'm trying to do it.

As described above, when the power of the apparatus is turned on, the normal applied voltage (DC) is applied to the water level detecting electrodes 41 and 42.
5V) (for example, about 7 V DC).
By applying the voltage for about 10 seconds every 20 hours, it is possible to remove or peel off impurities adhering to the water level detection electrodes 41 and 42 and the insulating film on the electrode surface, which lowers the water level detection accuracy of the storage tank 2. Can be prevented.

Further, since the application of the high voltage to the water level detecting electrodes 41 and 42 is performed only for a short time of about 10 seconds every about 720 hours, the storage tank 2 made of a conductive material such as copper or the like and the internal pipe 3 are applied. It is possible to suppress the occurrence of corrosion due to electric corrosion in the copper pipe constituting the above.

Further, even when the heating operation of the heat source unit is not performed for a long period of time, the cleaning operation of the water level detecting electrode is performed periodically at predetermined intervals, so that impurities can be prevented from accumulating and adhering to the water level detecting electrode.

FIG. 5 is a flowchart showing a case where the water level detecting electrode is cleaned according to the temperature of the circulating water according to still another embodiment of the present invention. In FIG. 5, first, the microcomputer 33 determines whether or not the heat source device 1 has started the heating operation in step S <b> 21. It is determined whether or not the temperature is about 10 ° C. or less (Step S22). If it is determined that the temperature is 10 ° C. or less, the timer 1 for about 10 seconds is set, and then the process goes to Step S24 to turn on the transistor Q1 and thus detect the water level. Electrode 41,
42 is applied with a high voltage of DC12V for 10 seconds (step S
24) (Water level detection electrode cleaning operation). I do. When the microcomputer 33 determines that the application of the high voltage has been performed for 10 seconds in step S25, the microcomputer 33 proceeds to step S2.
6, the transistor Q1 is turned off, and a low voltage of 5 V DC is applied to the water level detection electrodes 41 and 42 to execute a normal combustion operation process. During the execution of the combustion operation process (step S26), the heating operation stop signal is output from the microcomputer 33.
Is input to the microcomputer 33, the microcomputer 33 proceeds to step S27.
, The heating operation of the heat source unit 1 is stopped, the operation returns to the state before step S21, and the operation waits until the next operation start signal is input.

As described above, when the temperature of the circulating water is low, it is difficult for the current to flow. Therefore, when the temperature of the circulating water detected by the temperature sensor 25 drops to, for example, 10 ° C. or less, the water level detecting electrodes 41 and 42 are used. By applying a high voltage of 12 V DC to the electrodes, it is possible to remove or peel off impurities adhering to the water level detection electrodes 41 and 42 and the insulating film on the electrode surface, thereby preventing the water level detection accuracy of the storage tank 2 from being lowered. it can.

In addition, the application of the high voltage to the water level detecting electrodes 41 and 42 is performed only for a short time of about 10 seconds when the temperature of the circulating water detected by the temperature sensor 25 drops to, for example, 10 ° C. or less. Storage tank 2 made of conductive material such as copper or copper
And corrosion of the copper pipe constituting the internal pipe 3 due to electric corrosion.

The present invention is not limited to the above embodiment. For example, the storage tank is not limited to the pressure tank shown in one embodiment, but may be a storage tank or a hot water storage type can that is open to the atmosphere. It may be a storage tank,
Further, the storage tank may not be made of copper.

In addition, although the three embodiments in which cleaning is performed by applying a higher voltage than the normal applied voltage to the water level detection electrode have been described, it is needless to say that all or two of these three embodiments may be combined.

[0042]

As described above, the present invention has a structure provided with a control means for applying a voltage higher than a voltage normally applied to a water level detecting electrode provided in a storage tank for storing hot water such as circulating water. Therefore, it is possible to remove or peel off impurities adhering to the water level detection electrode and the insulating film on the electrode surface while suppressing the occurrence of corrosion due to electrolytic corrosion of the storage tank and internal piping, etc., and the water level detection accuracy of the storage tank And a hot water supply device capable of preventing a drop or malfunction of the hot water supply can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a heat source device for hot water heating according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a schematic configuration of the control device.

FIG. 3 is a flowchart showing a case in which a water level detection electrode is cleaned at the same time when a heating operation is started.

FIG. 4 is a flowchart illustrating a case of cleaning a water level detection electrode every predetermined period according to another embodiment of the present invention.

FIG. 5 is a flowchart illustrating a case where a water level detection electrode is cleaned according to the temperature of circulating water according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat source unit 2 Storage tank 4 Circulation pump 5 Outgoing header 6 Heat exchanger 7 Gas burner 14 Return header 18 Pressure cap 19 Overflow pipe 25 Inlet side temperature sensor 26 Outlet side temperature sensor 30 Remote controller 31 Load 32 Controller 33 Microcomputer (control Means) 35 Current supply circuit 41 Water level detection electrode 42 Water level detection electrode

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Juichi Takada 1 Otsukicho, Ashikaga, Tochigi Prefecture Sanyo Electric Air Conditioning Co., Ltd. (72) Inventor Yoshio Muto 1 Otsukicho, Ashikaga, Tochigi Prefecture Sanyo Electric Air Conditioning Co., Ltd. (72) Inventor Kiyoma Yamagishi 1F, Otsuki-cho, Ashikaga-shi, Tochigi Sanyo Electric Air Conditioning Co., Ltd. F-term (reference) 2F014 AA07 AA10 DA01 3L070 AA02 BB03 DD02 DE05 DE09 DF07

Claims (3)

[Claims] 1. A tank for storing hot and cold water such as circulating water, and a water level detection electrode provided in the tank for detecting the presence or absence of hot water in the tank. A hot and cold water supply device comprising control means for applying a voltage higher than a voltage applied at a normal time for a predetermined time. 2. A tank for storing hot and cold water such as circulating water, and a water level detecting electrode provided in the tank for detecting the presence or absence of hot water in the tank, the voltage being higher than a voltage normally applied to the water level detecting electrode. A hot and cold water supply device comprising control means for applying a voltage every predetermined period. 3. A tank for storing hot and cold water such as circulating water, a temperature sensor for detecting the temperature of the hot and cold water, and a water level detection electrode provided in the tank for detecting the presence or absence of hot or cold water in the tank. When the temperature sensor detects that the temperature of the hot water falls below a predetermined temperature, the hot water supply device further comprises control means for applying a voltage higher than a voltage normally applied to the water level detection electrode.