JP4879228B2 - Hot water heater - Google Patents

Description

  The present invention relates to a hot water heater that performs heating with heated heating water.

  2. Description of the Related Art Conventionally, a hot water supply apparatus that generates power using a thermoelectric generator during a hot water supply operation is known (see, for example, Patent Document 1). This hot water supply apparatus is provided with an element burner for heating the high temperature side of the thermoelectric generator in addition to a hot water burner for heating a heat exchanger connected between a water inlet pipe and a hot water outlet pipe. The high temperature side of the thermoelectric generator is heated by an element burner, and the low temperature side is cooled by a cooling water channel connected to a water inlet pipe. As is well known, a thermoelectric generator is a device in which a closed circuit is formed between an N-type semiconductor and a P-type semiconductor, and an electromotive force is obtained by applying a temperature difference between a high temperature side and a low temperature side. Electric power obtained from the element is supplied to an electric device or stored in a battery.

  In this hot water supply device, since the low temperature side of the thermoelectric generator is cooled by the water supplied from the inlet pipe, there is no need to provide a cooling water circuit only for cooling the low temperature side of the thermoelectric generator, and the device configuration is compact. Can be. However, on the other hand, in the state where no water flow is generated in the water inlet pipe, the cooling of the thermoelectric generator on the low temperature side is insufficient. For this reason, heating of the thermoelectric generator by the element burner is limited to the hot water supply operation, and sufficient power generation cannot be performed for a long time.

  Accordingly, a heat exchanger in which the heating water flows, a heating burner that heats the heat exchanger, a heating water circuit that circulates the heating water through a heat pump through the heat exchanger, and the heating water circuit It is conceivable to provide a thermoelectric generator in a hot water heater provided with a connected heating load. In other words, an element burner is provided separately from the heating burner to heat the high temperature side of the thermoelectric generator, and a cooling water passage for cooling the low temperature side of the thermoelectric generator is connected to the heating water circuit upstream of the heat exchanger. Since the heating operation is performed for a relatively long time, the low-temperature side of the thermoelectric generator can be cooled by the heating water of the heating water circuit circulated by the circulation pump during the heating operation, Sufficient power generation can be performed.

However, in the case where the hot water heater is operated with the commercial power source as the power source, the circulation pump stops when a power failure occurs in the commercial power source, and the water for heating that cools the low temperature side of the thermoelectric generator is accordingly accompanied. Flow also stops. For this reason, the cooling on the low temperature side becomes insufficient, and the temperature on the low temperature side becomes excessively high. In general, the heat-resistant temperature on the low temperature side of the thermoelectric generator is relatively low. At this time, the low-temperature side is higher than the heat-resistant temperature, and the thermoelectric generator may be burned out.
Japanese Patent Laid-Open No. 11-55975

  In view of the above points, the present invention provides a hot water heater that can reliably prevent burning of a thermoelectric generator when a power failure occurs in a commercial power source when generating power during a heating operation using the commercial power source as a power source. The issue is to provide.

  In order to solve this problem, the present invention provides a heat exchanger in which heating water flows, heating heating means for heating the heat exchanger, and heating water via the heat exchanger by a circulation pump. In a hot water heating apparatus comprising a heating water circuit to be circulated, a heating load connected to the heating water circuit, and a heating operation control means for controlling a heating operation using a commercial power source as a main power source, the temperature between the high temperature side and the low temperature side A thermoelectric generator that generates electricity due to the difference, an element heating means that heats a high temperature side of the thermoelectric generator, and a downstream side of a heating load of the hot water heating circuit, and uses the heating water as cooling water to cool the thermoelectric generator A thermoelectric generator comprising: a cooling water channel for cooling the battery; a battery for storing electric power obtained from the thermoelectric generator; and a power generation operation control means for controlling a power generation operation using the electric power from the battery as a power source. The turnover control means includes a power failure detection means for detecting a power failure of the commercial power supply, a power generation combustion stop means for stopping the element heating means when a power failure is detected by the power failure detection means, and a power failure detection by the power failure detection means. The power supply switching means for switching at least power supply to the circulation pump from a commercial power source to the battery is detected.

  In normal times, electric power is supplied from a commercial power source to the heating means for heating and the circulation pump of the hot water heater via the heating operation control means, and the electric power generated from the thermoelectric generator is supplied to the thermoelectric generator via the power generation operation control means. It is supplied to the element heating means and stored in the battery.

  When a power failure occurs in the commercial power supply, the power failure detection means of the power generation operation control means detects the power failure of the commercial power supply, the power generation combustion stop means stops the element heating means, and the power supply switching means commercializes power to the circulation pump. Switch from power to battery. As a result, even if a power failure occurs in the commercial power supply during the heating operation and the hot water heater is stopped, the circulation pump does not stop due to power supply from the battery, and the flow of the heating water that cools the low temperature side of the thermoelectric generator Is maintained. Therefore, the thermoelectric generator is sufficiently cooled on the low temperature side, and burning of the thermoelectric generator can be reliably prevented.

  Further, in the present invention, the power generation operation control means includes communication means for communicating with the heating operation control means, and the power failure detection means is unable to communicate with the heating operation control means by the communication means. The power supply from the commercial power source is regarded as being stopped, and a power failure of the commercial power source is detected. As a result, the power generation operation control means can easily detect that a power failure has occurred in the commercial power supply during the heating operation, and stop the element heating means by the power generation combustion stop means or supply to the circulation pump by the power supply switching means. The power feeding can be switched smoothly.

  By the way, after the heating operation of the hot water heater stops due to a power failure and the power generation in the thermoelectric generator stops, power is supplied to the circulation pump from the battery, so that the battery power is gradually consumed. On the other hand, if the element heating means stops and the temperature on the high temperature side of the thermoelectric generator sufficiently decreases, the thermoelectric generator does not burn out. Therefore, in the present invention, it is preferable that the power generation operation control unit includes a determination unit that determines a temperature decrease on the high temperature side of the thermoelectric generator, and stops the circulation pump based on a determination result by the determination unit. According to this, the circulation pump can be stopped when there is no risk of burning of the thermoelectric generator, and battery consumption can be suppressed.

  In this case, specifically, a power generation amount detecting means for detecting the power generation amount of the thermoelectric power generation element is provided, and the power generation amount of the thermoelectric power generation element detected by the power generation amount detection means is equal to or less than a predetermined power generation amount. By the way, the determination means can determine the temperature drop on the high temperature side of the thermoelectric generator. In addition, temperature detecting means for detecting the temperature on the low temperature side of the thermoelectric generator is provided, and when the temperature on the low temperature side detected by the temperature detecting means becomes a predetermined temperature or lower, The determination means can determine the temperature drop on the high temperature side of the thermoelectric generator.

  As shown in FIG. 1, a hot water heating apparatus 1 according to an embodiment of the present invention is heated by a heat exchanger 3 connected to a heating water circuit 2 and combustion exhaust of fuel gas supplied from a gas supply pipe 4. A first burner 5 for heating the exchanger 3 and a fan 6 for sending combustion air to the first burner 5 are provided. The gas supply pipe 4 connected to the first burner 5 is provided with a valve device 7 composed of a main valve, a gas amount adjusting valve and the like. The 1st burner 5 and the fan 6 comprise the heating means for heating of this invention with the ignition device and flame detection apparatus which are not shown in figure. Then, the ignition / extinguishing of the first burner 5, the operation of the fan 6, the operation of the valve device 7 and the like are controlled by the heating operation control means 8. Commercial electric power is supplied to the heating operation control means 8 via the commercial electric power line 9, and commercial electric power is supplied via the heating operation control means 8 to electric components that operate during the heating operation such as the fan 6 and the valve device 7. It has become.

  The heating water circuit 2 is connected to a heating load 10 such as floor heating or warm air heating in the house, and heating water is circulated by a circulation pump 11. The heat exchanger 3 includes a primary heat exchange unit 3a that collects sensible heat in the combustion exhaust discharged from the first burner 5, and a secondary heat exchange unit 3b that collects latent heat in the combustion exhaust. . A drain receiver 12 is provided below the secondary heat exchanger 3b to receive the drain generated from the secondary heat exchanger 3b and lead it to a neutralizer outside the figure.

  In the heating water circuit 2, a portion from the primary heat exchange unit 3 a to the heating load 10 is an outward path of the heating water, and a portion from the heating load 10 to the secondary heat exchange unit 3 b is a return path.

  When the heating operation described later is started, the heating water in the heat exchanger 3 is heated by the combustion exhaust of the first burner 5, and the heating water heated in the heat exchanger 3 by the operation of the circulation pump 11 is primary heat exchange. Heating water that has been sent from the part 3a along the forward path to the heating load 10 and has passed through the heating load 10 and has fallen in temperature flows along the return path and returns to the secondary heat exchange part 3b. The combustion exhaust generated from the first burner 5 passes through the primary heat exchange unit 3a and the secondary heat exchange unit 3b in this order and is discharged out of the apparatus. At this time, the secondary heat exchange unit 3b collects the latent heat in the combustion exhaust into the heating water flowing from the return path, and the primary heat exchange unit 3a collects the latent heat collected from the secondary heat exchange unit 3b. The sensible heat in the combustion exhaust is recovered to the water.

  The heating water circuit 2 is provided with a first temperature sensor 13 for detecting the temperature of the heating water flowing in the forward path and a second temperature sensor 14 for detecting the temperature of the heating water flowing in the backward path, and the heating operation control means 8 controls the combustion amount of the first burner 5 based on the temperatures of the first temperature sensor 13 and the second temperature sensor 14.

  Furthermore, the hot water heating apparatus 1 includes a thermoelectric generator 15. The thermoelectric generator 15 is combusted to the thermoelectric generator 16, the second burner 18 that heats the high temperature side of the thermoelectric generator 16 by the combustion exhaust or radiant heat of the fuel gas supplied from the gas supply pipe 17, and the second burner 18. And a fan 19 for sending in air. The gas supply pipe 17 connected to the second burner 18 is provided with a valve device 20 including a main valve, a gas amount adjusting valve, and the like. The second burner 18 and the fan 19 constitute the element heating means of the present invention together with an ignition device and a flame detection device (not shown). The power generation operation control means 21 controls the ignition / extinguishing of the second burner 18, the operation of the fan 19, the operation of the valve device 20, and the like. The power generation operation control means 21 is connected to the heating operation control means 8 by a signal line 22 via a communication means (not shown) so that the combustion control of the second burner 18 can be performed in conjunction with the control of the heating operation control means 8. Yes.

  A cooling water channel 23 is provided in close contact with the low temperature side of the thermoelectric generator 16. The cooling water channel 23 is connected to the downstream side of the heating load 10 which is the return path of the heating water circuit 2. Thus, the heating water whose temperature has been lowered through the heating load 10 is sent to the cooling water passage 23 as cooling water, and the low temperature side of the thermoelectric generator 16 is cooled by the heating water. The thermoelectric generator 16 generates electricity due to a temperature difference generated between the high temperature side and the low temperature side.

  In addition, an exhaust path 24 is provided above the second burner 18 to guide the combustion exhaust that has been heated on the high temperature side of the thermoelectric generator 16 to the vicinity of the heat exchanger 3. The exhaust path 24 introduces combustion exhaust from the second burner 18 between the primary heat exchange unit 3a and the secondary heat exchange unit 3b. Thereby, in the secondary heat exchange part 3b, the heat | fever of the combustion exhaust gas produced | generated by the 2nd burner 18 and heating the high temperature side of the thermoelectric generation element 16 can be collect | recovered to heating water.

  A power distribution means 26 is connected to the thermoelectric generator 16 via a generated power line 25 that extracts a power generation output from the thermoelectric generator 16. The power distribution unit 26 includes an inverter, a voltmeter, and the like, and includes a battery 27 that stores the power generation output of the thermoelectric generator 16 and a terminal 28 that supplies power to a power device such as a lighting device or a home electric appliance (not shown). It is connected. The power distribution unit 26 is connected to the power generation operation control unit 21 through a signal line 29 and is controlled by the power generation operation control unit 21. The power generation operation control means 21 is supplied with the power of the battery 27 via the power distribution means 26, and the electric power of the battery 27 is supplied to the electric components that operate during the power generation operation such as the fan 19 and the valve device 20 via the power generation operation control means 21. Is to be supplied.

  The power generation operation control unit 21 includes a power failure detection unit 30 (power failure detection unit), a combustion stop control unit 31 (power generation combustion stop unit), a determination unit 32, and a power supply switching unit 33 (power supply switching unit). . When the communication with the heating operation control means 8 becomes impossible, the power failure detection unit 30 detects that the power supply from the commercial power source is stopped and detects a power failure of the commercial power source. The combustion stop control unit 31 stops the combustion of the second burner 18 when a power failure is detected by the power failure detection unit 30. The determination unit 32 determines a temperature decrease on the high temperature side of the thermoelectric generator 16 when the temperature detected by the third temperature sensor 34 (temperature detection means) provided on the low temperature side of the thermoelectric generator 16 becomes a predetermined temperature or lower. To do. In addition to the determination based on the temperature detected by the third temperature sensor 34, the determination unit 32 is provided with a power generation amount detecting means for detecting the power generation amount of the thermoelectric power generation element 16. When the power generation amount becomes equal to or less than the predetermined power generation amount, a decrease in temperature on the high temperature side of the thermoelectric generator 16 may be determined. The power supply switching unit 33 is connected to a commercial power source via the heating operation control means 8 and is connected to the battery 27 via the power distribution means 26. The circulation pump 11 is connected to the power supply switching unit 33 and is selectively supplied with power from either the commercial power source or the battery 27. The power supply switching unit 33 switches the power supply to the circulation pump 11 from the commercial power source to the battery 27 when a power failure is detected by the power failure detection unit 30.

  Here, the operation of the power generation operation control means 21 when the commercial power supply fails will be described. During the heating operation by the hot water heater 1, the power generation operation control means 21 is linked with the heating operation control means 8, and the thermoelectric generator 15 also performs the power generation operation. During this time, the hot water heating apparatus 1 is heated by the power of the commercial power source, and the thermoelectric generator 15 is operated by the power generation operation control means 21 by the power of the battery 27. At this time, the electric power generated by the thermoelectric generator 16 is stored in the battery 27 at the same time except that supplied to the power generation operation control means 21.

  If the commercial power supply fails in this state, the power supply to the heating operation control means 8 is stopped, and the heating operation is stopped by shutting off the fuel gas supplied to the first burner 5 by the valve device 7 or the like. When the heating operation control means 8 is stopped due to a power failure, even if the power failure is resolved and the power supply from the commercial power supply is resumed, the heating operation control means 8 is in a stopped state until the operation start operation of the heating operation is performed.

  On the other hand, in the thermoelectric generator 15, when the power supply to the heating operation control means 8 is stopped, the power failure detection unit 30 of the power generation operation control means 21 detects a power failure of the commercial power supply. In response to this power failure detection, the combustion stop control unit 31 stops the combustion of the second burner 18, and at the same time, the power supply switching unit 33 switches the power supply to the circulation pump 11 to the battery 27. Thereby, electric power is supplied from the battery 27 to the circulation pump 11 at the time of a power failure, and circulation of the heating water in the heating water circuit 2 is continuously performed. Since the thermoelectric generator 16 maintains the flow of the heating water in the cooling water passage 23 by the circulation of the heating water, the low temperature side is sufficiently cooled, and the thermoelectric generator 16 is reliably prevented from being burned out.

  Thereafter, when the temperature detected by the third temperature sensor 34 decreases to a predetermined temperature, the determination unit 32 of the power generation operation control means 21 determines that the temperature on the high temperature side of the thermoelectric generator has decreased, and stops the circulation pump 11. By doing so, it is possible to prevent the battery 27 from being consumed due to the power supply to the circulation pump 11 and to prepare for the resumption of the heating operation.

  The thermoelectric generator 15 includes a terminal 28 connected to the power distribution means 26, so that power can be supplied from the battery 27 as a backup power source for other electric devices during a power failure of the commercial power source. By enabling power supply from the battery 27 to the heating operation control means 8, the heating operation can be resumed using the battery 27 as a power source even if the power failure has not been resolved.

  Further, the power failure detection unit 30 in the present embodiment detects the power failure of the commercial power source due to the inability to communicate with the heating operation control means 8, but is not limited to this, for example, the power of the commercial power source May be monitored and a power failure may be detected due to a reduction in power of the commercial power source.

  In the present embodiment, the cooling water passage 23 that cools the low temperature side of the thermoelectric generator 16 is connected in series to the return path between the heating load 10 and the heat exchanger 3 in the heating water circuit 2. However, in addition to this, a flow path branched from between the heating load 10 and the heat exchanger 3 is provided, and the cooling water path 23 is connected to the flow path, and the cooling water path 23 is connected to the heating load 10 and the heat exchanger 3. A part of the heating water may be used as cooling water for the thermoelectric generator 16 by connecting in parallel to the return path between them.

The schematic block diagram which shows the hot water heating apparatus of one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Hot water heating apparatus, 2 ... Heating water circuit, 3 ... Heat exchanger, 5 ... 1st burner (heating means for heating), 8 ... Heating operation control means, 10 ... Heating load, 11 ... Circulation pump, 15 ... Heat Power generation device, 16 ... thermoelectric power generation element, 18 ... second burner (element heating means), 21 ... power generation operation control means, 23 ... cooling water channel, 27 ... battery, 30 ... power failure detection unit (power failure detection means), 31 ... Combustion stop control unit (power generation combustion stop unit), 32 ... determination unit (determination unit), 33 ... power feeding switching unit (power feeding switching unit), 34 ... third temperature sensor (temperature detection unit).

Claims (5)

A heat exchanger in which heating water flows, heating heating means for heating the heat exchanger, a heating water circuit for circulating the heating water through a circulation pump via the heat exchanger, and the heating water circuit In a hot water heating apparatus comprising a connected heating load and a heating operation control means for controlling a heating operation using a commercial power source as a main power source,
A thermoelectric generator that generates electricity based on a temperature difference between the high temperature side and the low temperature side, element heating means that heats the high temperature side of the thermoelectric generator, and downstream of the heating load of the hot water heating circuit are connected to cool the heating water Thermoelectric generator having cooling water passage for cooling low temperature side of thermoelectric generator as water, battery for storing electric power obtained from thermoelectric generator, and power generation operation control means for controlling power generation operation using electric power from battery as power source With
The power generation operation control means includes a power failure detection means for detecting a power failure of the commercial power supply, a power generation combustion stop means for stopping the element heating means when a power failure is detected by the power failure detection means, and the power failure detection means. A hot water heating apparatus comprising: a power supply switching means for switching at least power supply to the circulation pump from a commercial power source to the battery when a power failure is detected by the power supply. The hot water heater according to claim 1,
The power generation operation control means includes communication means for performing communication with the heating operation control means,
The power failure detection means detects a power failure of the commercial power supply, assuming that power supply from the commercial power supply is stopped when communication with the heating operation control means by the communication means is disabled. Heating device. The hot water heating apparatus according to claim 1 or 2,
The hot water heating apparatus according to claim 1, wherein the power generation operation control means includes determination means for determining a temperature drop on the high temperature side of the thermoelectric generator, and stops the circulation pump based on a determination result by the determination means. The hot water heating apparatus according to claim 3,
A power generation amount detecting means for detecting the power generation amount of the thermoelectric generator;
The determination means determines a temperature drop on the high temperature side of the thermoelectric generation element when the power generation amount of the thermoelectric generation element detected by the power generation amount detection means is equal to or less than a predetermined power generation amount. Heating device. The hot water heating apparatus according to claim 3,
Comprising temperature detecting means for detecting the temperature on the low temperature side of the thermoelectric generator,
The said determination means determines the temperature fall of the high temperature side of the said thermoelectric power generation element, when the temperature of the low temperature side detected by this temperature detection means becomes below predetermined temperature, The hot water heating apparatus characterized by the above-mentioned.

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