JPH10227526A - Hot water feeding device with anti-freezing function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water feeding device having an anti-freezing function capable of performing a positive and efficient anti-freezing operation for an entire hot water feeding device. SOLUTION: This hot water feeding device having an anti-freezing function comprises a heat exchanging section 3 for heating water from a water supplying passage 1 by a heat exchanger 3a and supplying the water to a hot water feeding passage 2; a combustion heating section 4 composed of a burner 4a for heating the heat exchanger 3a; and a combustion control means 7 for sensing a water feeding state in a water feeding pipe 11 extending from the water supplying passage 1 to the hot water feeding passage 2, performing a normal combustion at the burner 4a under a state of feeding water and for performing prevention of freezing and performing combustion at the burner 4 if it satisfies the predetermined condition of anti-freezing and combustion even if the water feeding operation is stopped. The water feeding pipe 11 is divided into an upper pipe 12 including the heat exchanging section 3 and a lower pipe passage 13 other than the upper one. The lower pipe 13 is provided with a lower pipe heating means 15. There is provided a pipe heating control means 16 for performing a control operation if an anti-freezing combustion starting condition is satisfied under a condition of stopped feeding of water, heating of the lower pipe heating means 15 is started and in turn, if it satisfies a condition of stopping an anti-freezing combustion, it is controlled to be stopped.

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 device having an antifreezing function.

[0002]

2. Description of the Related Art As a hot water supply device with an anti-freezing function, a heat exchange unit that heats water from a water supply passage by a heat exchanger and supplies the water to the hot water supply passage, and a combustion heating unit including a burner that heats the heat exchanger. Detecting the state of water passage in the water supply passage or the hot water supply passage, controlling the combustion of the burner to start in a water passage state, and to stop in a water stop state. Combustion control means for controlling the combustion to start when the predetermined freezing prevention combustion start condition is satisfied and to stop when the predetermined freezing prevention combustion stop condition is satisfied. It has been proposed (Japanese Patent Application No. 8
-178848). In addition, conventionally, as a hot water supply device with an antifreeze function, in order to prevent the temperature of the outside air from dropping and the residual water in the water supply pipe extending from the water supply channel to the hot water supply channel to freeze and damage the appliance beforehand, As a heating means for heating residual water in a water flow pipe, there is a heating means provided with an electric heater in an appliance. In addition, as means for controlling the start and stop of the operation of the electric heater according to the outside air temperature, a configuration in which a heat-sensitive switch that conducts at a predetermined temperature or less is connected in series to the electric heater, or a water supply thermistor that detects a water supply temperature. There has been a configuration in which a water temperature in a water flow pipe is monitored, and when the water temperature falls below a predetermined temperature, a relay connected in series with the electric heater is closed to energize the electric heater.

[0003]

However, in the above-described hot water supply device having a function of preventing freezing due to the combustion of the burner, the hot water supply device is provided with the heat exchange section which is heated by the combustion of the burner and located in the vicinity thereof. The upper pipe section consisting of a water supply channel and a hot water supply path, the residual water is heated and freezing can be prevented, but the lower pipe section of the water supply pipe consisting of a water supply path and a hot water supply path located below the heat exchange section is There is a danger that the residual water will not be heated and will be damaged by freezing.

On the other hand, in the hot water supply device having a function of preventing freezing by the electric heater, depending on the structure of the heat exchanger, the electric heater directly heats a part of a water pipe of the heat exchanger other than a pipe exposed to the outside. However, there is a problem in terms of heating efficiency in ensuring freezing prevention over the entire heat exchanger even in an extremely low temperature state.

The present invention has been made in view of such a point, and an object of the present invention is to provide a hot water supply apparatus having a freezing prevention function capable of reliably and efficiently executing the prevention of freezing of the entire hot water supply apparatus.

[0006]

[Means for Solving the Problems]

[Configuration] To achieve this object, a first characteristic configuration of the hot water supply device with an antifreezing function according to the present invention is to heat water from a water supply channel as described in claim 1 of the claims. A heat exchange unit for heating the heat exchanger to supply the hot water to the hot water supply path; a combustion heating unit including a burner for heating the heat exchanger; and a combustion state of the burner by detecting a water flow state in the water supply path or the hot water supply path. Start in the water flow state, control to stop in the water flow stop state, start the combustion of the burner when the predetermined freeze prevention combustion start condition is satisfied even in the water stop state,
Combustion control means for controlling to stop when a predetermined freezing prevention combustion stop condition is satisfied, a water supply pipe extending from the water supply path to the hot water supply path, an upper pipe section including the heat exchange section, and The lower pipe section is divided into a lower pipe section including a lower part of the water supply path and the hot water path, and a lower pipe heating means is provided in the lower pipe section. The present invention is characterized in that a pipe heating control means for starting heating of the heating means and controlling to stop when the above-mentioned freeze prevention combustion stop condition is satisfied is provided.

According to a second feature of the invention, as described in claim 2 of the claims, in addition to the first feature of the invention, an upper pipe heating means is provided in the upper pipe section, The pipe heating control means starts heating of the upper pipe heating means when the burner does not start burning when the freeze prevention combustion start condition is satisfied in the water stop state, and the freeze prevention combustion is performed. The point is to control so as to stop when the stop condition is satisfied.

According to a third feature of the present invention, as described in claim 3 of the claims, in addition to the above-mentioned first feature, an upper pipe heating means is provided in the upper pipe section, The upper pipe heating means is configured by connecting an electric heater and a heat-sensitive switch that conducts at a predetermined temperature or less in series, and the heat-sensitive switch is mounted at a position capable of detecting a water temperature or an ambient temperature of the upper pipe portion. It is in.

[Functions and Effects] The functions and effects of the above features will be described below. According to the first feature configuration, the upper pipe portion can be reliably prevented from freezing regardless of the structure of the heat exchanger by the freeze prevention function due to the combustion of the burner, and the freeze prevention function by the lower pipe heating means allows the freeze prevention function. It is also possible to prevent freezing of the lower pipe portion, which cannot be prevented only by burning the burner, and to prevent freezing of the entire hot water supply device in the water flow pipe.

Here, in order to prevent the entire heat exchanger from freezing even in an extremely low temperature state and to prevent the lower piping portion of the water flow piping from freezing, a conventional hot water supply device with an antifreezing function is used. A simple combination of the function of preventing freezing by combustion of a burner and the function of preventing freezing by an electric heater can be considered, but in the case of such a simple combination, a hot water supply device having a function of preventing freezing by a conventional electric heater is required.
It should be noted that since the electric heater is attached to both the upper piping section and the lower piping section, the following disadvantages occur.

First, a temperature sensor for detecting the water temperature or the ambient temperature of the water flow pipe used for controlling the start and stop of heating by the electric heater is provided in the pipe of the lower pipe section or in the peripheral section thereof. In this case, the function of preventing freezing due to the combustion of the burner and the function of preventing freezing by the electric heater are simultaneously activated, and the upper piping is heated twice for the purpose of preventing freezing. There is a problem that consumption is unnecessarily increased. Further, when the temperature sensor is provided in or around the pipe of the upper pipe section, when the freeze prevention function due to combustion of the burner operates, the temperature sensor is in a state where the upper pipe section is in a heated state. There is a danger that the lower pipe portion will be damaged by freezing without detecting and activating the freeze prevention function of the electric heater.

Therefore, according to the first characteristic configuration, the problem caused by a simple combination of the above-described freezing prevention function by burning the burner and the freezing prevention function by the electric heater in the conventional hot water supply device with the freezing prevention function is also solved. is there.

As a result, it is possible to provide a hot water supply apparatus having a freezing prevention function capable of reliably and efficiently executing the prevention of freezing of the entire hot water supply apparatus.

[0014] According to the second characteristic configuration, in the situation where the freeze prevention combustion start condition is satisfied in the water stoppage state and the combustion of the burner must be started, the fuel supply path to the burner should be started. Even if the burner does not start burning due to factors such as the main plug being closed, the heating by the upper pipe heating means is started, so that freezing prevention over the entire hot water supply device can be more reliably executed. is there. Further, if the combustion of the burner starts as scheduled, the upper pipe heating means does not start heating, so that unnecessary power consumption by the upper pipe heating means is suppressed.

According to the third characteristic configuration, the heat-sensitive switch is set to be conductive under the same or substantially the same temperature condition as the freeze prevention combustion start condition. If the combustion start condition is satisfied and the combustion of the burner starts as scheduled, even if the thermal switch is once conductive, as the upper piping is heated by the combustion of the burner, the conduction of the thermal switch is turned on. , The heating by the upper pipe heating means is stopped, and unnecessary power consumption by the upper pipe heating means is suppressed. Further, in the condition where the freeze prevention combustion start condition is satisfied in the water stop state and the burner should start burning, the main plug of the fuel supply passage to the burner is closed due to factors such as closing. Even if a failure occurs in which the combustion of the burner does not start, the thermal switch is turned on, the heating by the upper pipe heating means is started, and the upper pipe section is heated. The conduction of the thermal switch is maintained and the heating by the upper pipe heating means is continued until the water temperature or the ambient temperature of the upper pipe section becomes equal to or higher than the predetermined temperature, so that the upper pipe section always becomes equal to or higher than the predetermined temperature. As a result, freezing can be prevented.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a hot water supply device having a freeze preventing function according to the present invention (hereinafter, referred to as the present invention) will be described with reference to the drawings. As shown in FIG. 1, the apparatus of the present invention includes a heat exchange unit 3 that heats water from a water supply passage 1 with a heat exchanger 3a and supplies the water to a hot water supply passage 2, and a combustion heating unit that heats the heat exchanger 3a. 4, the combustion heating unit 4 includes a burner 4a and an ignition means 4 for the burner 4a.
b and a flame detector 4c. The burner 4a receives the fuel supply from the gas supply path 5 and the supply of combustion air from the combustion fan 6, and the combustion control means 7 supplies the fuel supply and combustion air. Combustion is performed by appropriately controlling the supply, and the heat exchanger 3a is heated. Also,
The gas supply path 5 is provided with a hot water supply gas solenoid valve 5a, a gas flow control valve 5b, and a source gas solenoid valve 5c. Near the upstream end of the water supply path 1, a water quantity sensor 8 for measuring a water supply amount and a water supply sensor A water supply thermistor 9 for measuring temperature is further provided, and a hot water supply thermistor 10 for measuring hot water supply temperature is provided in the hot water supply passage 2 immediately adjacent to the heat exchanger 3a.

A remote control operation unit (not shown) for giving an instruction such as a set hot water supply temperature to the combustion control means 7 and displaying information on a combustion state from the combustion control means 7 is provided by the apparatus of the present invention. The combustion control means 7 further detects the state of water flow to the heat exchanger 3a by receiving a water flow detection signal 8a from the water amount sensor 8, and detects the water supply thermistor. 9 and based on each water temperature information from the hot water supply thermistor 10 and a set hot water supply temperature instructed from the remote control operation unit.
The required combustion amount is set by calculation, and the fuel supply amount and the combustion air supply amount are set based on the set combustion amount.
A normal combustion control means 7a for controlling the number of revolutions of the combustion fan 6 is provided.

As shown in FIG. 1, in addition to the basic configuration of the hot water supply apparatus, the combustion control means 7 according to the present invention does not need to receive the water flow detection signal 8a from the water quantity sensor 8, That is, even if the inside of the heat exchanger 3a is in the water stop state, the combustion of the burner 4a is started when a predetermined freezing prevention combustion start condition is satisfied, and the heat exchange section 3 is heated to a predetermined freezing. An antifreeze combustion control means 7b is provided for controlling the burner 4a to stop combustion when the prevention combustion stop condition is satisfied.

Further, a water supply pipe 11 extending from the water supply channel 1 to the hot water supply channel 2 is provided at an upper pipe portion 12 of the heat exchange portion 3 and at a lower portion of the water supply channel 1 and the hot water supply channel 2 below the heat exchange portion 3. The upper pipe section 12 is divided into a lower pipe section 13.
An upper pipe heating means 14 for heating a predetermined portion of the lower pipe portion 12 to prevent freezing of residual water in the upper pipe portion 12, and a predetermined portion of the lower pipe portion 13 for heating the lower pipe portion 13.
Pipe heating means 1 to prevent freezing of residual water
5 are provided. Here, the heat exchange unit 3 includes a portion of the water supply passage 1 and the hot water supply passage 2 immediately adjacent to the heat exchanger 3a.

Further, when the water temperature detected by the hot water supply thermistor 10 located in the upper piping section 12 is equal to or lower than a predetermined temperature, it is determined that a freeze warning state corresponding to a state in which the freeze prevention combustion start condition is satisfied. Then, the operation of the upper pipe heating means 14 is started, and when the water temperature detected by the water supply thermistor 9 located in the lower pipe section 13 is equal to or lower than a predetermined temperature, it is determined that the freeze warning state is established and the lower Pipe heating control means 1 for starting operation of pipe heating means 15
6 is provided.

As shown in FIG. 1, the upper pipe heating means 14 comprises a plurality of electric heaters 14a, a commercial AC power supply 19, and a relay switch 14b connected in series, as shown in FIGS. As described above, each of the electric heaters 14a is provided in proximity to the upper piping section 12, in particular, a plurality of locations of the water passage pipe 11 outside the combustion chamber 20 of the heat exchanger 3a. Further, as shown in FIG. 1, the lower pipe heating means 15 shares the commercial AC power supply 19 with the upper pipe heating means 14, and a plurality of electric heaters 15a, the commercial AC power supply 19 and the relay switch 15b are provided. Each of the electric heaters 15a is provided in close proximity to a plurality of portions of the lower piping portion 13, as shown in FIGS. The relay switch 14b,
The opening / closing operation of 15b is individually controlled by the pipe heating control means 16.

The water supply thermistor 9 constitutes a sensor part of the temperature sensor 17 for detecting the above-mentioned anti-freezing combustion start condition, the anti-freezing combustion stop condition, and the above-mentioned freeze warning state. Further, the hot water supply thermistor 10 also constitutes a sensor part of the temperature sensor 18 for detecting the freeze warning state. Therefore, the detection outputs of the temperature sensors 17 and 18 are input to the normal combustion control means 7a, the antifreeze combustion control means 7b, and the pipe heating control means 16.

The combustion control means 7 and the pipe heating control means 16 comprising the normal combustion control means 7a and the anti-freezing combustion control means 7b, together with a main control section 21 for controlling and managing these operations, are provided by a general micro-controller. It comprises a computer system 22. Specifically, the various control means 7a, 7b, 16, 21 are stored in the microcomputer system 22 as built-in programs,
U is realized by sequentially executing the built-in program.

The control of the antifreeze combustion control means 7b and the pipe heating control means 16 of the lower pipe section 13 in the antifreeze function of the apparatus of the present invention will be described below with reference to the flowchart shown in FIG. . In the following description and FIG. 5, Tk is the water supply thermistor 9.
Is the detected temperature in the water supply channel. The flag is a 1-bit temporary storage device, and is set to 1 when set, and set to 0 when reset.

After the power supply of the present invention is turned on, if the lower pipe heating means 15 (described as a heater in FIG. 5) is operating in step # 1, the operation is stopped.
The relay switch 15b is turned off, and the flag is reset. In step # 2, the operation waits until the operation switch is turned on. After the operation switch is turned on, it is determined in step # 3 that the water amount sensor 8 has detected the presence / absence of water flow in the water flow pipe 11, and if there is a water flow, the flow proceeds to step # 4.
It becomes a normal combustion control system, and if there is no water flow, step # 5
Proceed to and become the antifreeze control system.

Hereinafter, the freeze prevention control system will be described. In step # 5, it is determined whether or not the water supply channel temperature Tk is equal to or lower than a set temperature at which the operation of the freeze prevention function is started. In the embodiment shown in FIG. 5, the freezing prevention function is started only when the temperature Tk in the water supply channel is 3 ° C. or less, and then the normal combustion is started or the temperature Tk in the water supply channel is 15 ° C. or more. It is programmed to continue the antifreeze heating by the antifreeze function until it rises to. If the water supply channel temperature Tk is 3 ° C. or less, the process proceeds to step # 6, in which the anti-freezing combustion of the burner 4a is started, the relay switch 15b of the lower pipe heating means 15 is turned on, and the heating of the electric heater 15a is started. And set the flag. The flag 1 (set state) indicates that the temperature Tk in the water supply channel once becomes 3 ° C. or lower, and the antifreeze control system is in a state where the antifreeze heating should be continued.

Incidentally, the start of the antifreeze combustion of the burner 4a starts when the antifreeze combustion control means 7b rotates the combustion fan 6 without receiving the water flow detection signal 8a from the water quantity sensor 8. At the same time that the ignition means 4b is started and spark starts, the normal combustion control means 7a sets the hot water supply gas solenoid valve 5a and the original gas solenoid valve 5c.
Is opened. A predetermined amount of fuel gas at the time of ignition set by the gas flow control valve 5b is supplied to the burner 4a, and when the ignition of the burner 4a is completed, the flame detector 4c detects a flame and the spark is detected. Stops. Further, the antifreeze combustion control means 7b calculates a required gas amount necessary for antifreeze based on the water supply channel temperature Tk,
The opening degree of the gas flow control valve 5b and the rotation speed of the combustion fan 6 are set. Thereafter, the opening degree of the gas flow control valve 5b and the combustion fan 6 are determined based on the water supply path temperature Tk.
Starts continuous freezing prevention combustion while controlling the number of revolutions.

In the next step # 7, the result of the detection of the presence or absence of the water flow in the water pipe 11 by the water amount sensor 8 is determined.
If there is a water flow, the process proceeds to step # 4, and shifts to a normal combustion control system. If there is no water flow in step # 7, step # 8
Then, it is determined whether the operation switch is on or off. If it is on, the process proceeds to step # 5 and the same procedure is repeated. If the operation switch is off, the process proceeds to step # 9, where the antifreeze combustion of the burner 4a is stopped, the process returns to step # 1, and the same procedure is repeated.

If it is determined in step # 5 that the water supply channel temperature Tk is higher than 3 ° C., the process proceeds to step # 10, where the flag is set to 1
Is determined. If the flag is 0, the process returns to step # 2, and the same processing is repeated. If the flag is 1, the routine proceeds to the next step # 11, where it is determined whether or not the temperature Tk in the water supply channel is 15 ° C. or higher. When the temperature in the water supply channel Tk is less than 15 ° C. and the condition for continuing the heating state for freezing prevention is satisfied, step #
7, the same processing is repeated. Step # 11
If it is determined that the water supply channel temperature Tk is equal to or higher than 15 ° C., the process proceeds to step # 9, and after stopping the antifreeze combustion of the burner 4a, returns to step # 1 and repeats the same procedure.

The outline of the normal combustion control will be described below. In step # 4, if the lower pipe heating means 15 is operating, the relay switch 15b is turned off to stop the operation, and the flag is reset. Next step # 12
In the above, the normal combustion control means 7a includes the burner 4
In order to start the normal combustion of the combustion fan 6, the water flow detection signal 8 a from the water amount sensor 8 is received and the combustion fan 6
Is rotated to start the ignition means 4b, and at the same time as the spark starts, the normal combustion control means 7a opens the hot water supply gas solenoid valve 5a and the original gas solenoid valve 5c. A predetermined amount of fuel gas at the time of ignition set by the gas flow control valve 5b is supplied to the burner 4a.
When the ignition of a is completed, the flame detector 4c detects the flame and the spark stops.

The normal combustion control means 7a detects the water supply amount and the water supply temperature by the water amount sensor 8 and the water supply thermistor 9, calculates the required gas amount from the set hot water temperature, and determines the opening degree of the gas flow control valve 5b. The number of revolutions of the combustion fan 6 is set. Thereafter, normal hot combustion is started while the opening degree of the gas flow rate regulating valve 5b and the rotation speed of the combustion fan 6 are controlled by the hot water supply thermistor 10 so as to reach the set hot water temperature.

In parallel with the normal combustion operation, as shown in FIG. 5, the operation switch is turned on in step # 13, and the water flow detection signal 8a of the water flow sensor 8 is constantly turned on in step # 14. If the operation switch is turned off, the process proceeds to step # 15, and the burner 4a
Is stopped and the process returns to step # 1. If the flow of water in the water pipe 11 stops, the process proceeds to step # 16, where the normal combustion operation of the burner 4a is stopped and the process proceeds to step # 5. The above-described process of the freeze prevention control system is repeated.

The control of the pipe heating control means 16 relating to the antifreeze combustion control means 7b and the lower pipe heating means 15 and the normal combustion control of the normal combustion control means 7a have been described above. Heating means 14
Regarding the control of the pipe heating control means 16 relating to
The difference lies in that there is no control relating to the normal combustion and the antifreezing combustion of the burner 4a, and that the temperature in the hot water supply path detected by the hot water supply thermistor 10 is used instead of the temperature Tk in the water supply path detected by the water supply thermistor 9. Other than that, the details are omitted because they are in accordance with the control of the pipe heating control means 16 relating to the lower pipe heating means 15.

The operation state of the upper pipe heating means 14 is as follows.
This is executed when the temperature in the hot water supply passage becomes equal to or higher than a predetermined temperature due to the antifreeze combustion of the burner 4a, and the antifreeze heating is released. In the case of the lower pipe heating means 15, the anti-freezing heating is canceled when the temperature Tk in the water supply channel is 15 ° C. or higher, but the upper pipe heating means 14 is set at a temperature lower than 15 ° C. In addition, it is possible to prevent the operation state of the upper pipe heating means 14 from overlapping with the antifreeze combustion state of the burner 4a for a long time.

(Another Embodiment) A second embodiment of the present invention will be described below. As shown in FIG. 6, only the configuration of the upper pipe heating means 14 is different from that of the first embodiment shown in FIG. 1, and the configuration of the other parts is the same. As shown in FIG. 6, the upper pipe heating means 14 in the second embodiment
Are connected to the lower pipe heating means 15 and the commercial AC power supply 19.
And the relay switch 15b, and a plurality of electric heaters 14a, the commercial AC power supply 19, and the relay switch 15b.
Are connected in series. The thermal switch 14
c is, for example, a bimetal switch, which is attached to a predetermined location of the upper piping section 12 in proximity to the piping. Further, each electric heater 14a is, similarly to the first embodiment, individually provided with the upper piping section 12, particularly the heat exchanger 3a.
Are provided in close proximity to a plurality of locations of the water flow pipe 11 outside the combustion chamber 20. In the case of the second embodiment, since the heat-sensitive switch 14c functions as a temperature sensor 18 for detecting the freeze warning state, it is not necessary to use the hot water supply thermistor 10 for detecting the freeze warning state,
The output signal of the temperature detection is input only to the normal combustion control means 7a.

Hereinafter, the freeze prevention function of the device of the present invention in the second embodiment will be described. The control of the antifreeze combustion control means 7b and the pipe heating control means 16 relating to the lower pipe section 13 is the same as in the first embodiment.

In the case of the second embodiment, the pipe heating control means 16 does not directly control the upper pipe heating means 14. That is, since the lower pipe heating means 15 and the relay switch 15b are shared, when the pipe heating control means 16 turns on the lower pipe heating means 15, the upper pipe heating means 14 The switch is turned on or off according to the open / close state of the thermosensitive switch 14c. Conversely, when the pipe heating control means 16 turns off the lower pipe heating means 15, the upper pipe heating means 14 is forcibly turned off regardless of the open / close state of the thermal switch 14c. This is because the thermal switch 14c has only a function of detecting the temperature,
The other condition judgments are configured in common with those for the lower pipe heating means 15.

The threshold temperature at which the thermal switch 14c is turned on or off with respect to the ambient temperature in the upper piping section 12 is set to be equal to or slightly higher than the water supply path temperature Tk satisfying the above-mentioned freezing prevention combustion start condition. If there is a certain temperature difference between the ambient temperature and the water supply channel temperature Tk, the temperature is set in consideration of the temperature difference. Therefore, when the freeze prevention combustion start condition is satisfied and it is determined that the vehicle is in the freeze warning state, the relay switch 15b
And the thermal switch 14c is turned on at the same time, or the relay switch 15b is turned on in a state where the thermal switch 14c is already turned on, and the upper pipe heating means 14 once starts heating. However, the temperature in the hot water supply passage becomes equal to or higher than a predetermined temperature due to the antifreeze combustion of the burner 4a, the thermal switch 14c detects the temperature rise and turns off. Will be canceled. The burner 4
If antifreeze combustion of a does not cause antifreeze combustion for some reason, antifreeze heating is continued. Incidentally, by appropriately adjusting the set threshold temperature, even when the antifreeze combustion of the burner 4a does not perform the antifreeze combustion for some reason, the antifreeze heating can be sufficiently performed, and the upper pipe heating means 14 It is possible to prevent the operation state and the combustion state for preventing freezing of the burner 4a from overlapping for a long time.

Hereinafter, another embodiment will be described.

In the first embodiment, it is determined whether or not the anti-freezing combustion state of the burner 4a is operating normally based on the water temperature detected by the hot water supply thermistor 10, and based on a result thereof, Relay switch 14b
The opening and closing of the heater is controlled, but may be performed based on the detection result of the flame detector 4c provided in the combustion heating unit 4 without depending on the water temperature detected by the hot water supply thermistor 10, for example. . In this case, when the opening and closing of the relay switch 14b is simply controlled by only the detection result of the flame detector 4c, the configuration is such that the thermal switch 14c of the second embodiment is replaced with the relay switch 14b. This is preferred because the control procedure for the upper pipe heating means 14 is simplified.

The upper pipe section 12 and the lower pipe section 13
Is not necessarily limited to the above embodiment. For the purpose of the present invention, the upper pipe portion 12 is a portion which is heated to a degree sufficient to prevent freezing due to the combustion of the burner 4a, and the lower pipe portion 13 is a portion which is not heated to a degree sufficient to prevent freezing. For example, the method of division can be appropriately changed according to the structure of the heat exchange unit 3, and is not simply determined only by the positional relationship in the vertical direction.

In the above first or second embodiment,
The upper pipe heating means 14 and the lower pipe heating means 1
5 is a plurality of the electric heaters 14a, 15a, the commercial AC power supply 12b, and the relay switches 14b, 15b.
May be other than those connected in series. For example, the plurality of electric heaters 14a and 15a may be connected in parallel in each of the heating means 14 and 15, respectively.

The operation of the freeze prevention function of the apparatus of the present invention is not necessarily limited to the procedure shown in the flowchart of FIG. Further, the various control means 7a, 7b, 16, 21 may be constituted by dedicated custom circuits without depending on the microcomputer system 22. The control procedure may be configured by random logic without depending on the program.

[0044]

As described above, according to the present invention,
It is possible to efficiently combine a hot water supply device with an anti-freezing function due to burner combustion and a hot water supply device with an anti-freezing function using heating means other than the burner, and as a result, by partially selecting and activating each anti-freezing function, A hot water supply device with a freezing prevention function that can reliably and efficiently execute the prevention of freezing of the entire hot water supply device can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the device of the present invention.

FIG. 2 is an external front view of an upper pipe section, a lower pipe section, and a combustion chamber.

FIG. 3 is an outer left side view of an upper pipe section, a lower pipe section, and a combustion chamber.

FIG. 4 is an outer right side view of an upper pipe section, a lower pipe section, and a combustion chamber.

FIG. 5 is a flowchart illustrating a freeze prevention function of the apparatus of the present invention.

FIG. 6 is a configuration diagram showing a second embodiment of the device of the present invention.

[Description of Signs] 1 Water supply path 2 Hot water supply path 3 Heat exchange section 3a Heat exchanger 4 Combustion heating section 4a Burner 7 Combustion control means 7a Normal combustion control means 7b Antifreeze combustion control means 11 Water pipe 12 Upper pipe section 13 Lower Pipe section 14 Upper pipe heating means 14a, 15a Electric heater 14c Thermal switch 15 Lower pipe heating means 16 Pipe heating control means

Claims (3)

[Claims] 1. A heat exchange unit for heating water from a water supply channel with a heat exchanger and supplying the same to a hot water supply channel, a combustion heating unit including a burner for heating the heat exchanger, and Control of the burner to start in the water flow state and stop in the water stop state, and to prevent the burner from burning even when the water flow is stopped. A water control apparatus having a freeze prevention function, comprising: a combustion control unit that starts when the start condition is satisfied and controls to stop when a predetermined freeze prevention combustion stop condition is satisfied. A water supply pipe extending over the hot water supply path is divided into an upper pipe section including the heat exchange section and a lower pipe section including the water supply path and a lower portion of the hot water supply path. In the water stop state, Plus the heating of the lower pipe heating means is started when the freeze prevention combustion becomes comprise a pipe heating control means for controlling to stop when the stop condition has been satisfied antifreeze function water heater. 2. An upper pipe heating means is provided in the upper pipe section, and the pipe heating control means satisfies the freeze prevention combustion start condition in the water stop state, and the burner does not start burning. 2. The method according to claim 1, wherein the heating of the upper pipe heating means is started and stopped when the anti-freezing combustion stop condition is satisfied.
A hot water supply device with a freezing prevention function as described. 3. An upper pipe heating means is provided in the upper pipe section, and the upper pipe heating means is configured by connecting an electric heater and a heat-sensitive switch conducting at a predetermined temperature or less in series,
The hot water supply device with a freezing prevention function according to claim 1, wherein the heat-sensitive switch is mounted at a position where the water temperature or the ambient temperature of the upper piping portion can be detected.