JP2010007944A - Household hot-water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a household hot-water heater for achieving high energy-saving performance by efficiently combining air-heating and power generation. <P>SOLUTION: This hot-water heater includes a first burner 7 for heating a heat exchanger 5 in which the water for air heating is circulated, by an exhaust gas, a second burner 18 for heating a high temperature-side of a thermal power generating element 16, an exhaust passage 23 for supplying the exhaust gas generated in the second burner 18 between the first burner 7 and the heat exchanger 5, a heating operation control means 13 for controlling a heating operation, and a power generating operation control means 22 for controlling a power generating operation. The power generating operation control means 22 supplies the electric power corresponding to the minimum electric power consumed in the home from the thermal power generating element 16 as a part of a household power source. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a domestic hot water heater that performs heating in the home with heated heating water.

  Conventionally, as can be seen in Patent Document 1, there is known an apparatus for generating electricity by heating a thermoelectric generator provided in a water heater with a flame of a burner during a hot water supply operation. As is well known, a thermoelectric generator has a closed circuit 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. The electric power obtained from the thermoelectric generator can be supplied to other electrical components, stored in a battery or the like, and further supplied as a household power source.

  In this type of apparatus, the thermoelectric generator and the heat exchanger are heated by a burner, hot water is generated in the heat exchanger, and at the same time, electric power is generated by the thermoelectric generator. According to this, since the heat of the burner can be efficiently used by the thermoelectric generator and the heat exchanger, the energy saving property is improved. However, in a configuration in which the thermoelectric generator and the heat exchanger are heated by a single burner, the burner combustion amount may decrease as the hot water temperature is adjusted. In this case, heating of the thermoelectric generator is not effective. As a result, the necessary temperature difference cannot be obtained and the power generation efficiency deteriorates. For this reason, the power generation state in the thermoelectric generator becomes unstable. For example, when supplying electric power obtained from the thermoelectric generator as a household power source, it is difficult to maintain stable power supply.

Patent Document 1 also describes a configuration in which a power generation burner for heating the thermoelectric generator is provided separately from the burner for heating the heat exchanger. According to this, since a constant combustion amount can be maintained in the power generation burner, stable power supply from the thermoelectric generator can be performed without being affected by the combustion amount of the heat exchanger burner. However, when the thermoelectric generator is heated by the power generation burner, heat other than that absorbed by the thermoelectric generator during power generation is released together with the exhaust, and this exhaust heat is wasted and is uneconomical. . Furthermore, for example, when heating water heating is performed by connecting a heating load to the heat exchanger described above, the operation takes a relatively long time. Therefore, the exhaust heat after heating the thermoelectric generator from the power generation burner. Occurs for a long time, and energy saving is low. Thus, the conventional configuration cannot efficiently achieve both heating and power generation, and there is a disadvantage that sufficient energy saving cannot be obtained.
JP-A-11-55975 (FIGS. 2, 6, and 7)

  In view of the above points, an object of the present invention is to provide a domestic hot water heating apparatus that can achieve both high efficiency and energy saving by efficiently combining heating and power generation.

  In order to solve this problem, the present invention provides a domestic hot water heating apparatus that performs heating in the home with heated heating water, a heat exchanger in which the heating water flows, and the heat exchanger by combustion exhaust. Thermoelectric power generation that generates power by a temperature difference between a first burner to be heated, a heating water circuit in which heating water circulates through the heat exchanger, a heating load connected to the heating water circuit, and a high temperature side and a low temperature side An element, a second burner that heats the high temperature side of the thermoelectric generator, an exhaust passage that guides combustion exhaust generated by the second burner toward the heat exchanger, and cooling water flows through the inside A cooling water passage for cooling the low temperature side of the thermoelectric generator, heating operation control means for controlling heating operation by the first burner and the second burner, and power generation operation control means for controlling power generation by the thermoelectric generator, Power generation Control means, when the heating operation is being performed, the power corresponding to the minimum of the power consumed in the home and supplying from the heat generating element as a part of the domestic power supply. Here, the minimum electric power consumed at home is electric power that is expected to be consumed at home, centering on standby electric power such as a refrigerator.

  In the present invention, since the heat exchanger is heated by the first burner and the thermoelectric generator is heated by the second burner, stable power generation can be performed in the thermoelectric generator without being affected by the combustion amount of the first burner. it can. The combustion exhaust of the second burner after heating the thermoelectric generator is guided toward the heat exchanger by the exhaust path, so that the exhaust heat of the second burner can also be used for heating the heating water. As a result, it is possible to efficiently supply power from the thermoelectric generator during the heating operation for a relatively long time, and at the same time, it is possible to obtain a sufficient heating performance by suppressing the combustion amount of the first burner. Sex can be obtained. In addition, since power generation and heating are linked, it is possible to increase power generation efficiency and heating efficiency.

  Furthermore, according to the above configuration, the electric power obtained from the thermoelectric generator is supplied as a part of the household power supply, and the electric power at this time is the electric power corresponding to the minimum electric power consumed in the home. In this case, even if the power load fluctuates within a day, the minimum power can always be stably supplied, and the combustion amount of the second burner can be kept relatively small to further improve energy saving. it can. In addition, according to the above configuration, the electric power obtained from the thermoelectric generator can be directly supplied as a part of the household power supply, so that the electric power can be used without waste. Even if the capacity is kept low, power can be supplied reliably.

  In the present invention, when the heating operation is performed, the heating operation control means preferably increases or decreases the combustion amount of the first burner according to the required heating capacity, and the heating operation control means When the required heating capacity is exceeded even when the combustion amount of the first burner is minimized, the combustion of the first burner is preferably stopped. According to this, it is possible to adjust the heating amount of the heating water by increasing / decreasing the combustion amount of the first burner or stopping the combustion while maintaining the stable heating of the thermoelectric generator by the combustion of the second burner. Stable power generation can be performed without being affected by the increase / decrease.

  Further, when the required heating capacity is exceeded even when the combustion of the first burner is stopped, the heating operation control means stops the combustion of the second burner, and the residual heat of both burners where the combustion is stopped is reduced. By using it, it is economical to generate power using residual heat while keeping the heating capacity small.

  Moreover, in this invention, the said cooling water channel is connected downstream from the said heating load of the said hot water heating circuit, and the low temperature side of the said thermoelectric generation element is cooled with the heating water which goes to the said heat exchanger from a heating load. Is preferred. According to this, since the low temperature side of the thermoelectric generator can be cooled by the heating water that has passed through the heating load, the low temperature side of the thermoelectric generator can be reliably secured only by circulating the heating water along the heating water circuit. Can be cooled to.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a domestic hot water heating apparatus of the present embodiment, FIG. 2 is a flowchart showing operation control in the domestic hot water heating apparatus of the present embodiment, and FIG. 3 is a daily power load fluctuation and heat in the home. It is a diagram which shows the electric power supplied from a power generation element. Details of each part will be described below.

  As shown in FIG. 1, the domestic hot water heating apparatus 1 of the present embodiment includes a heating combustion unit 2 and a power generation combustion unit 3. The heating combustion unit 2 includes a heat exchanger 5 connected to the heating water circuit 4, a first burner 7 that heats the heat exchanger 5 by combustion exhaust of fuel gas supplied from the gas supply pipe 6, and a first burner And a fan 8 for feeding combustion air into the air. The heating water circuit 4 is connected to a heating load 9 such as floor heating or hot air heating in the house, and heating water is circulated by a circulation pump 10. The heat exchanger 5 includes a primary heat exchange unit 5a that collects sensible heat in the combustion exhaust discharged from the first burner 7, and a secondary heat exchange unit 5b that collects latent heat in the combustion exhaust. . Below the secondary heat exchange section 5b, there is provided a drain receiver 11 that receives the drain generated from the secondary heat exchange section 5b and guides it to a neutralizer outside the figure.

  The gas supply pipe 6 connected to the first burner 7 is provided with a valve device 12 including a main valve, a gas amount adjusting valve, and the like. The ignition / extinguishing of the first burner 7, the operation of the fan 8, the operation of the valve device 12, and the like are controlled by the heating operation control unit 13 (heating operation control means).

  In the heating water circuit 4, a part from the primary heat exchange unit 5 a to the heating load 9 is a forward path of the heating water, and a part from the heating load 9 to the secondary heat exchange unit 5 b is a return path.

  When the heating operation described later is started, the heating water in the heat exchanger 5 is heated by the combustion exhaust of the first burner 7, and the heating water heated in the heat exchanger 5 by the operation of the circulation pump 10 is primary heat exchange. The heating water that has been sent from the part 5a along the forward path to the heating load 9 and has passed through the heating load 9 and has fallen in temperature flows along the return path and returns to the secondary heat exchange part 5b. The combustion exhaust generated from the first burner 7 passes through the primary heat exchange unit 5a and the secondary heat exchange unit 5b in this order and is discharged out of the apparatus. At this time, the secondary heat exchanger 5b recovers the latent heat in the combustion exhaust to the heating water flowing from the return path, and the primary heat exchanger 5a recovers the latent heat recovered from the secondary heat exchanger 5b. The sensible heat in the combustion exhaust is recovered to the water.

  The heating water circuit 4 is provided with a first temperature sensor 14 for detecting the temperature of the heating water flowing in the forward path and a second temperature sensor 15 for detecting the temperature of the heating water flowing in the backward path, and the heating operation control unit 13 controls the amount of combustion of the first burner 7 based on the temperature of the first temperature sensor 14 and the second temperature sensor 15.

  The power generation / combustion unit 3 combusts the thermoelectric power generation element 16, the second burner 18 that heats the high temperature side of the thermoelectric power generation element 16 by 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. A cooling water channel 20 is provided in close contact with the low temperature side of the thermoelectric generator 16. The cooling water channel 20 is connected to the downstream side of the heating load 9 that is the return path of the hot water heating circuit 4. Thereby, the heating water whose temperature has decreased through the heating load 9 is sent to the cooling water channel 20 as cooling water, and the low temperature side of the thermoelectric generator 16 is cooled by this heating water. The thermoelectric generator 16 generates electricity due to a temperature difference generated between the high temperature side and the low temperature side.

  The gas supply pipe 17 connected to the second burner 18 is provided with a valve device 21 including a main valve, a gas amount adjusting valve, and the like. The ignition / extinguishing of the second burner 18, the operation of the fan 19, the operation of the valve device 21, and the like are controlled by the power generation operation control unit 22 (power generation operation control means). The power generation operation control unit 22 is connected to the heating operation control unit 13 so that the combustion control of the second burner 18 can be performed in conjunction with the control of the heating operation control unit 13.

  Further, an exhaust path 23 is provided above the second burner 18 to guide the combustion exhaust gas that has been heated on the high temperature side of the thermoelectric generator 16 to the heating combustion unit 2. The exhaust path 23 introduces combustion exhaust of the second burner 18 between the primary heat exchange unit 5a and the secondary heat exchange unit 5b. Thereby, in the secondary heat exchange part 5b, the heat of the combustion exhaust gas generated by the second burner 18 and heating the high temperature side of the thermoelectric generator 16 can be recovered into the heating water.

  A power distribution device 25 is connected to the thermoelectric generator 16 via a generated power line 24 that extracts a generated output from the thermoelectric generator 16. Commercial power is supplied to the power distribution device 25 via the commercial power line 26, and the power generation output and the commercial power are linked to form a household power source, and power is supplied to a power device 27 such as a lighting fixture or a home appliance. The power distribution device 25 distributes the power generation output used as a household power source and the commercial power by the power generation operation control unit 22.

  Note that a battery 28 that stores the power generation output of the thermoelectric generator 16 may be connected to the power distribution device 25. In this case, when surplus power is generated in the power from the thermoelectric generator 16, the surplus output is stored in the battery 28 via the power distribution device 25, or the power from the thermoelectric generator 16 and the battery 28 are stored. Can be switched by the power distribution device 25 and supplied.

  Next, the operation of the domestic hot water heating apparatus 1 configured as described above will be described. Referring to FIG. 2, when the user performs an operation start operation of domestic hot water heating apparatus 1, first, heating operation control unit 13 starts driving circulation pump 10 in STEP 1. Thereby, a water flow is generated in the cooling water channel 20 in which the heating water circulates along the heating water circuit 4 and is in close contact with the low temperature side of the thermoelectric generator 16.

  Next, in STEP2, the power generation operation control unit 22 starts combustion of the second burner 18, and in STEP3, the heating operation control unit 13 starts combustion of the first burner 7. Thereby, the high temperature side of the thermoelectric generator 16 is heated, and the temperature difference between the high temperature side and the low temperature side of the thermoelectric generator 16 becomes large, and the thermoelectric generator 16 starts to generate power. Further, the heating water heated by the first burner 7 is supplied to the heating load 9 for heating.

  Here, the power generation operation control unit 22 controls the power distribution device 25 to supply power corresponding to the minimum power consumed at home from the thermoelectric generator 16 as a part of the household power source. That is, as shown in FIG. 3, it is possible to confirm that the power load (power consumption) in a part of the time period is the smallest in the day by measuring and collecting the power load fluctuation in the home in advance in one day. Therefore, by supplying the electric power at this time (in the present embodiment, about 300 W) from the thermoelectric generator 16 for one day, the minimum electric power consumed at home is supplied for one day. The amount of commercial power consumed can be reduced accordingly. In particular, in cold districts and the like, heating operation is continuously performed for a relatively long time in winter, so that the electric power from the thermoelectric generator 16 can be supplied as a part of the household power source for a long time. it can.

  Next, as shown in FIG. 2, the temperature (hereinafter referred to as return temperature) of the heating water detected by the second temperature sensor 15 provided in the return path of the heating water circuit 4 by the heating operation control unit 13 and the set temperature in STEP 4. When the return temperature exceeds the set temperature, the process proceeds to STEP5. The set temperature is a temperature set by a user's operation and corresponds to the heating capacity required in the heating operation.

  In STEP 5, the heating operation control unit 13 performs temperature control to reduce the combustion amount of the first burner 7. At this time, the combustion exhaust of the second burner 18 is introduced between the primary heat exchange part 5a and the secondary heat exchange part 5b, so that the combustion amount of the first burner 7 can be made relatively small, Energy saving is improved.

  Then, it progresses to STEP6 and a return temperature is compared with preset temperature. When the return temperature exceeds the set temperature in STEP 6, it is in a state exceeding the required heating capacity even if the combustion amount of the first burner 7 is minimized, so that the process proceeds to STEP 7 and the heating operation control unit 13 performs the first burner 7. Stop burning.

  Next, in STEP 8, the return temperature is compared with the set temperature. When the return temperature does not exceed the set temperature in STEP 8, the process proceeds to STEP 9 to start combustion of the first burner 7, and the process returns to STEP 5. And usually, the process of STEP5 to STEP9 is repeated and heating operation is continued. Thus, the heating water is heated by the combustion exhaust heat of the first burner 7 and the combustion exhaust heat of the second burner 18, so that an efficient heating operation is continued, and the second burner 18 is combusted. Stable power supply is maintained from the thermoelectric generator 16 without being affected by the combustion amount of the one burner 7. Therefore, according to this embodiment, both heating and power generation can be efficiently achieved, and extremely high energy saving can be obtained for a long time. Moreover, in the power generation operation control unit 22, for example, when unnecessary surplus power is generated from the power supplied from the thermoelectric generator 16, the battery 28 can be charged.

  Here, in STEP8, when the return temperature exceeds the set temperature, it is considered that the required heating capacity is exceeded even if the combustion of the first burner 7 is stopped, and the process proceeds to STEP10 to proceed to the power generation operation control unit. The combustion of the second burner 18 is stopped by 22. Thereby, supply of the combustion exhaust from the 2nd burner 18 between the primary heat exchange part 5a and the secondary heat exchange part 5b stops, and the temperature rise of the water for heating is suppressed. In STEP 11, when the return temperature is lower than the set temperature, the power generation operation control unit 22 starts combustion of the second burner 18 in STEP 12, and the process returns to STEP 8. As described above, the combustion control of the second burner 18 is also linked to the heating operation, whereby fine temperature control can be performed in a relatively low range of the set temperature, which is easy to use.

  Even when the combustion of the second burner 18 is stopped, the heating water is circulated by the operation of the circulation pump 10 and the cooling of the thermoelectric generator 16 on the low temperature side is continued. During this time, the thermoelectric generator 16 continues to generate power while receiving the remaining heat of the second burner 18, and when the power supplied from the thermoelectric generator 16 decreases, the power generation operation control unit 22 causes the power distribution device 25 to perform power generation. It is possible to switch to power supply from the battery 28 via the power supply and supply power as part of the household power supply.

  Moreover, in this embodiment, although what showed the combustion exhaust of the 2nd burner 18 between the primary heat exchange part 5a and the secondary heat exchange part 5b of the heat exchanger 5 was shown, It is also possible to introduce the combustion exhaust of the second burner 18 between the primary heat exchange part 5a, and even when the heat exchanger 5 has only a single heat exchange part, the first burner 7 and the heat exchanger If the combustion exhaust gas of the second burner 18 is introduced between the second burner 18 and the combustion exhaust heat of the second burner 18, it can be used for heating.

  In the present embodiment, the cooling water channel 20 that cools the low temperature side of the thermoelectric generator 16 is connected in series to the return path between the heating load 9 and the heat exchanger 5 in the heating water circuit 4. However, in addition to this, a flow path branched from between the heating load 9 and the heat exchanger 5 is provided, and the cooling water path 20 is connected to the flow path, and the cooling water path 20 is connected to the heating load 9 and the heat exchanger 5. 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 domestic hot water heating apparatus of one Embodiment of this invention. The flowchart which shows the operation control in the domestic hot water heating apparatus of this embodiment. The diagram which shows the electric power load fluctuation | variation of 1 day in a home, and the electric power supplied from a thermoelectric generator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Domestic hot water heating apparatus, 5 ... Heat exchanger, 4 ... Heating water circuit, 7 ... 1st burner, 9 ... Heating load, 13 ... Heating operation control part (heating operation control means), 16 ... Thermoelectric generation element, 18 ... 2nd burner, 20 ... Cooling water channel, 22 ... Power generation operation control part (power generation operation control means), 23 ... Exhaust channel.

Claims (5)

In a domestic hot water heating apparatus for heating in the home with heated heating water,
A heat exchanger in which heating water flows, a first burner that heats the heat exchanger by combustion exhaust, a heating water circuit in which heating water circulates through the heat exchanger, and a connection to the heating water circuit The generated heating load, the thermoelectric generator that generates electricity by the temperature difference between the high temperature side and the low temperature side, the second burner that heats the high temperature side of the thermoelectric generator, and the combustion exhaust generated by the second burner An exhaust path for guiding toward the exchanger, a cooling water path in which cooling water flows inside to cool the low temperature side of the thermoelectric generator, heating operation control means for controlling the heating operation, and power generation for controlling the power generation operation Operation control means,
The power generation operation control means supplies the electric power corresponding to the minimum electric power consumed in the home from the thermoelectric generator as a part of the household power source when the heating operation is performed. Hot water heater. The domestic hot water heating apparatus according to claim 1,
When the heating operation is performed, the heating operation control means increases or decreases the combustion amount of the first burner according to the required heating capacity. In the domestic hot water heating device according to claim 2,
The domestic hot water heater is characterized in that the heating operation control means stops the combustion of the first burner when the required heating capacity is exceeded even if the combustion amount of the first burner is minimized. The domestic hot water heater according to claim 3,
The heating operation control means stops the combustion of the second burner when the required heating capacity is exceeded even if the combustion of the first burner is stopped. The domestic hot water heating apparatus according to any one of claims 1 to 4,
The cooling water channel is connected to the downstream side of the heating load of the hot water heating circuit, and the low temperature side of the thermoelectric generator is cooled by heating water from the heating load toward the heat exchanger. Hot water heater.

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