JP6331461B2 - Hot water heater - Google Patents

Description

  The present invention relates to a hot water supply and heating device, and more particularly to a switchable from proportional combustion control to on / off combustion control in which combustion is intermittently performed in accordance with a required combustion amount of a heat source machine.

  2. Description of the Related Art Conventionally, hot water supply and heating devices having a function of supplying hot water to hot water heating terminals such as hot water storage, hot water supply, and floor heating panels have been widely used. This hot water heater is a hot water storage tank for storing hot water heated by an external heat source device or an internal heat source device, an auxiliary heat source device for heating hot water in the hot water storage tank, a water supply system passage for supplying low temperature clean water to the hot water storage tank, A hot water supply passage that supplies hot water stored in a hot water storage tank to a desired hot water supply destination such as a hot water tap, a hot water heating circuit that circulates heating water to a hot water heating terminal, and a heat utilization circulation circuit that heats the heating water of the hot water heating circuit Etc.

  A heat exchanger for heating is installed between the heat utilization circulation circuit and the hot water heating circuit. During the heating operation, the hot water heated by the auxiliary heat source machine flows through the heat utilization circulation circuit and heats the heating water flowing through the heating water heating circuit via the heating heat exchanger, and this heated heating water is heated and heated. It is circulated to the terminal. Generally, when hot water is heated by burning an auxiliary heat source machine, the temperature of hot water flowing into the auxiliary heat source machine is detected, and auxiliary water is output so that hot water at a set temperature is output from the auxiliary heat source machine according to this hot water temperature. Proportional combustion control of the amount of combustion of the heat source machine.

  By the way, when the heating load of the hot water heating terminal is low during heating operation and the hot water temperature returning to the auxiliary heat source machine does not decrease (the temperature difference between the hot water temperature output from the auxiliary heat source machine and the hot water temperature flowing into the auxiliary heat source machine is small) ), It becomes necessary to heat the hot water with a combustion amount lower than the minimum combustion amount within the range of the proportional combustion control. In this case, the hot water is heated by switching from the proportional combustion control to the on-off combustion control in which the combustion of the auxiliary heat source unit is intermittently performed. However, even if intermittent combustion is performed by controlling on / off combustion of the auxiliary heat source machine, the combustion amount may be excessive.

  Therefore, in order to solve the above problem, for example, in the combustion control method of the hot water heating system of Patent Document 1, the normal proportional combustion mode in which proportional combustion is performed in the normal proportional combustion range and the minimum combustion amount in the normal proportional combustion range. And an extended proportional combustion mode in which proportional combustion is performed in an extended proportional combustion range in which a low extended minimum combustion amount is set. When one cycle time of combustion on / off of the heat source unit on-off combustion control is shortened, the normal proportional combustion mode A technique for extending one cycle time by switching from 1 to an extended proportional combustion mode and further reducing the amount of combustion is disclosed.

Japanese Patent No. 4222271

  In the heat source device of Patent Document 1, a single function with a low output capability is used, and proportional combustion is performed using all of the plurality of combustion tubes constituting the burner during heating operation. In addition to the heating function, In the case of a hot water supply / heater apparatus having a hot water supply function, a bath chase function, or the like, a heat source apparatus having a plurality of combustion stages with high output capability is used. For this reason, when the heating operation is independently performed in the hot water heater, since the combustion amount becomes excessive when all the combustion stages of the heat source unit are burned, the number of combustion stages (the number of combustion tubes in the combustion pipe) is reduced. Proportional combustion control is desirable.

  However, if the number of combustion stages of the heat source unit (the number of combustion tubes in the combustion tube) is reduced, air that has not been heated from the non-combustion part of the combustion stage is supplied to the heat exchanger for hot water heating and cooled. There is a problem that exchange efficiency deteriorates. To solve this problem, we want to increase the number of combustion stages (the number of combustion tubes in the combustion tube) and perform combustion. However, as soon as the combustion range is increased, the combustion will be excessive and the combustion will turn on and off repeatedly. The durability of the machine is reduced. On the other hand, if the combustion amount is lowered after increasing the combustion region, the length of the flame generated by the burner becomes extremely short, and it becomes difficult to maintain a stable combustion state. Similarly, in the single-function heat source device of Patent Document 1, it becomes difficult to maintain a stable combustion state as the combustion amount is lowered.

  An object of the present invention is to prevent an excessive amount of combustion of a heat source machine in a hot water heater and reduce the repetition frequency of combustion on / off of on / off combustion control, and extremely low heat exchange efficiency of the heat source machine It is possible to provide a device capable of preventing the above, a device capable of maintaining a stable combustion state, and the like.

The hot water supply and heating device according to claim 1 is a heat source device, a heat utilization circulation circuit that circulates hot water heated by combustion with the heat source device, a hot water heating circuit that circulates heating water to an external hot water heating terminal, and the heat utilization In a hot water supply and heating device including a heating heat exchanger that performs heat exchange between a circulation circuit and the hot water heating circuit, all or large of a plurality of combustion stages constituting a burner of the heat source unit during heating operation A large combustion mode in which combustion is performed using a portion and the heat source device is controlled in proportion combustion control or on-off combustion control in accordance with the heating load of the hot water heating terminal; and a combustion region narrower than the combustion region in the large combustion mode and in a non-combustion region comprising a hot water heating control means and a combustion mode in which proportional combustion control or on-off combustion control the heat source apparatus according to the heating load of the water heating device and sets a wide combustion zone than the temperature The heating control means is configured to start the medium combustion from the large combustion mode when the on / off number of the on / off combustion control exceeds a set number during a set period, or when one cycle time of the on / off combustion control falls below a set time. It is characterized by switching to the mode.

  According to a second aspect of the present invention, there is provided a hot water supply and heating apparatus according to the first aspect of the present invention, comprising a hot water storage tank capable of storing hot water, and the hot water heating control means maintains the number of combustion stages in the middle combustion mode in the on-off combustion control. In the ON period, a part of the high-temperature hot water output from the heat source unit is returned to the upper part of the hot water storage tank, and the low temperature hot water is supplied from the lower part of the hot water storage tank to the heat utilization circulation circuit. A hot water storage and heat dissipation mode in which hot water is circulated and supplied to the heating heat exchanger to perform heating operation during the off period of the on-off combustion control. The heating control means is provided when the on / off combustion control on / off frequency during the set period exceeds the set number of times, or when one cycle time of the on / off combustion control falls below a set time. It is characterized in that switching from the combustion mode to the hot water storage tank heat storage and release mode.

  According to the first aspect of the present invention, the hot water heating control means is large when the on / off number of on / off combustion control exceeds the set number during the set period, or when one cycle of the on / off combustion control falls below the set time. Since the combustion mode is switched to the medium combustion mode, the heating load of the hot water heating terminal is low, the cycle time of the on / off combustion control is shortened, and the combustion of the heat source machine is performed before the combustion on / off is frequently repeated. The amount can be reduced automatically.

  Therefore, by reducing the combustion amount of the heat source machine, it is possible to extend the on period of the combustion on state, extend the cycle time of on / off combustion control, and the repetition frequency of combustion on / off is reduced. In the middle combustion mode, the combustion area is set to be narrower than the combustion area in the large combustion mode and wider than the non-combustion area, so that the heat exchange efficiency of the heat source machine is extremely reduced. Can be prevented.

  According to the second aspect of the present invention, during the heating operation in the hot water storage tank heat dissipation mode, during the ON period of the on / off combustion control, a part of the hot water output from the heat source unit is returned to the upper part of the hot water storage tank. By supplying low-temperature hot water from the lower part to the heat utilization circuit, the temperature of the hot water flowing into the heat source unit is lowered, so that the on-period of the combustion on state can be extended while maintaining the combustion amount of the heat source unit. Since it is not necessary to extremely reduce the combustion amount of the machine, a stable combustion state can be maintained.

  Furthermore, during heating operation in the hot water storage tank heat dissipation mode, during the off period of the on / off combustion control, hot water in the hot water storage tank is circulated and supplied to the heat exchanger for heating to perform the heating operation. By preventing a significant decrease, the off period of the combustion off state can be extended. That is, by using the hot water storage tank as a high-temperature hot water buffer while maintaining the number of combustion stages in the middle combustion mode, it is possible to extend one cycle time of on-off combustion control.

In addition, the hot water heating control means, when the on / off combustion control on / off count during the set period exceeds the set number in the medium combustion mode , or when one cycle time of the on / off combustion control falls below the set time, Since the hot water storage tank heat dissipation mode is switched from the mode, if the combustion on / off of the on / off combustion control is frequently repeated in the middle combustion mode, the control for extending the cycle time using the hot water tank can be automatically performed. .

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram of the cogeneration system with which the hot-water supply heating apparatus which concerns on the Example of this invention was integrated. It is a schematic block diagram of a hot water heater. It is a schematic block diagram of the hot-water supply heating apparatus in the combustion-on state at the time of the heating operation by hot water storage tank thermal radiation mode. It is a schematic block diagram of the hot-water supply heating apparatus in the combustion-off state at the time of the heating operation by hot water storage tank thermal radiation mode. It is a flowchart of heating operation control.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

First, the overall configuration of the hot water supply / room heating device 3 of the present invention will be described.
As shown in FIGS. 1 to 4, the hot water supply and heating device 3 has functions such as hot water storage, hot water supply, hot water supply to the bathtub and reheating of the bathtub, and supply of heating water to the hot water heating terminal 10 such as a floor heating panel. A hot water storage tank 4, an auxiliary heat source machine 5, a bath heat utilization heat exchanger 6, a heating heat utilization heat exchanger 7, a water supply passage 8, a hot water passage 9, a pouring passage 11, a bath memorial circuit 12, A hot water heating circuit 13, a heat utilization circulation circuit 14, an exhaust heat recovery circulation circuit 15, a control unit 45, and the like are provided, and most of them are housed integrally in an exterior case 16.

  As shown in FIG. 1, the hot water heater 3 is a fuel cell power generator 2 capable of heating hot water in a hot water storage tank 4 as an external heat source device, and between the fuel cell power generator 2 and the hot water heater 3. The fuel cell cogeneration system 1 is configured by combining it with the exhaust heat recovery circuit 15 for circulating hot water and the like, but detailed description of the configuration other than the hot water heater 3 is omitted.

Next, the hot water storage tank 4 will be described.
The hot water storage tank 4 is composed of a sealed tank capable of storing high-temperature hot water (eg, 65 to 90 ° C.) heated by an external heat source device, and the tank periphery is covered with a heat insulating material to prevent heat dissipation of the stored hot water. It has been broken. A plurality of hot water temperature detection sensors 4 a to 4 d are provided in order at equal intervals from the lower side to the upper side on the outer peripheral portion of the hot water storage tank 4, and a plurality of hot water temperature detection sensors 4 a to 4 d are provided in the hot water storage tank 4. The hot water temperature of the reservoir is detected.

Next, the auxiliary heat source unit 5 will be described.
The auxiliary heat source unit 5 (corresponding to a heat source unit) is configured by a known gas water heater that incorporates a burner, a heat exchanger, and the like. The auxiliary heat source unit 5 is instructed by combustion from the control unit 45 only in a special case such as when the hot water temperature in the hot water storage tank 4 is lowered during the reheating operation, the heating operation, or the hot water supply operation, Heats hot water.

  The auxiliary heat source unit 5 includes a blower fan 5a for supplying combustion air, a multistage burner unit 5b for burning fuel gas, a sensible heat recovery heat exchanger 5c for recovering mainly sensible heat of the combustion gas, a sensible heat A latent heat recovery heat exchanger 5d that mainly recovers latent heat of the recovered combustion exhaust gas, a drain water recovery unit 5e that recovers drain water generated in the latent heat recovery heat exchanger 5d, and the like are provided.

  The burner unit 5b is configured in a multistage manner having a plurality of (for example, five) combustion stages. Each combustion stage is provided with, for example, three combustion pipes and can be controlled independently by the control unit 45, and the number of stages of the combustion stage in which combustion is performed is adjusted according to various operations.

Next, the bath heat utilization heat exchanger 6 and the heating heat utilization heat exchanger 7 will be described.
The bath heat utilization heat exchanger 6 heats the bathtub water flowing through the bath remedy circuit 12, and the primary side heat exchange passage portion 6 a that is a part of the heat utilization circulation circuit 14 and the bath remedy circuit 12. It has the secondary side heat exchange passage part 6b which becomes a part. In the bath heat utilization heat exchanger 6, heat is exchanged between the hot water flowing through the heat utilization circulation circuit 14 and the bath water flowing through the bath memorial circuit 12, and the bath water is heated.

  The heating heat utilization heat exchanger 7 heats the heating water flowing through the hot water heating circuit 13, and forms a part of the primary side heat exchange passage portion 7 a and the hot water heating circuit 13 that are part of the heat utilization circulation circuit 14. The secondary side heat exchange passage portion 7b is formed. In the heating heat utilization heat exchanger 7, heat is exchanged between the hot water flowing through the heat utilization circulation circuit 14 and the heating water flowing through the hot water heating circuit 13, and the heating water is heated.

Next, the water supply system passage 8 will be described.
The water supply system passage 8 supplies low temperature clean water from a water supply source to the hot water storage tank 4 and the like, and has an upstream water supply passage portion 8a, an intermediate water supply passage portion 8b, and a downstream water supply passage portion 8c, and the upstream end is at the upper end. Connected to the water source, the downstream end is connected to the lower part of the hot water storage tank 4. A pressure reducing valve 8d is installed in the upstream water supply passage 8a, and a check valve 8e is installed in the intermediate water supply passage 8b.

  A bypass passage portion 17 connected to the hot water supply passage 9 is branched from between the upstream water supply passage portion 8a and the intermediate water supply passage portion 8b. A check valve 17 a is installed in the bypass passage portion 17. A bypass passage 18 connected to the heat utilization circulation circuit 14 is branched from between the intermediate water supply passage 8b and the downstream water supply passage 8c. A heat storage switching valve 19 is installed at this branch portion. By this bypass passage 18, low temperature clean water can be supplied to the heat utilization circuit 14, and conversely, hot water can be returned from the heat utilization circuit 14 to the hot water storage tank 4.

Next, the hot water supply system passage 9 will be described.
The hot water supply passage 9 supplies hot water stored in the hot water storage tank 4 to a desired hot water supply destination such as a bath, and is connected to the hot water supply passage 21 connected to the hot water tap and the hot water supply passage 21 from the upper part of the hot water storage tank 4. A tank hot water passage 22, an auxiliary heating passage 23 branched from the tank hot water passage 22 and connected to the combustion type auxiliary heat source device 5, an auxiliary heat source machine hot water passage 24 connected from the auxiliary heat source device 5 to the hot water supply passage 21, etc. have.

  The hot water supply passage 21 includes an upstream hot water supply passage portion 21a through which high-temperature hot water flows, an intermediate hot water supply passage portion 21b through which mixed hot water flows, and a downstream hot water supply passage portion 21c. The upstream end is connected to the tank hot water supply passage 22 and the downstream end is hot water supply. Connected to the stopper.

  A mixing valve 25 is installed between the upstream hot water supply passage portion 21a and the intermediate hot water supply passage portion 21b. A bypass passage portion 17 branched from the water supply passage 8 is connected to the mixing valve 25. The mixing valve 25 controls the mixing ratio of low temperature tap water and high temperature hot water so that the tapping temperature becomes the command temperature. A flow rate sensor 21d and a tapping water proportional valve 26 are installed in the intermediate hot water supply passage 21b. A branch passage portion 27 branched from the bypass passage portion 17 is connected to the intermediate hot water supply passage portion 21b, and a high temperature hot water avoidance electromagnetic valve 28 is installed in the branch passage portion 27.

  The tank hot water passage 22 has an upper effluent hot water passage portion 22 a and a lower effluent hot water passage portion 22 b, an upstream end connected to the upper portion of the hot water storage tank 4, and a downstream end connected to the hot water supply passage 21. An auxiliary heating passage 23 is branched from between the upper effluent passage portion 22a and the lower effluent passage portion 22b.

  The auxiliary heating passage 23 has an upstream heating passage portion 23 a and a downstream heating passage portion 23 b, the upstream end is connected to the tank hot water passage 22, and the downstream end is connected to the inlet of the auxiliary heat source unit 5. A check valve 23c is installed in the upstream heating passage portion 23a, and a hot water temperature detection sensor 23e for detecting the temperature of hot water flowing into the auxiliary heat source unit 5, a pumping pump 29, and a flow rate sensor are installed in the downstream heating passage portion 23b. 23d are installed.

  A three-way valve 31 capable of switching between the tank hot water passage 22 and the auxiliary heating passage 23 is installed between the upstream heating passage portion 23a and the downstream heating passage portion 23b. The three-way valve 31 is also connected with a hot water return side passage portion 14 d of the heat utilization circulation circuit 14. The three-way valve 31 can switch connection / disconnection between the upstream heating passage portion 23a and the downstream heating passage portion 23b and connection / disconnection between the downstream heating passage portion 23b and the hot water return side passage portion 14d. Yes, all the passage portions of the upstream heating passage portion 23a, the downstream heating passage portion 23b, and the hot water return side passage portion 14d can be connected.

  The auxiliary heat source machine outlet hot water passage 24 has an upstream auxiliary hot water outlet passage 24 a and a downstream auxiliary hot water outlet passage 24 b, the upstream end is connected to the outlet of the auxiliary heat source machine 5, and the downstream end is connected to the upstream end of the hot water supply passage 21. Has been. A hot water / outward side passage portion 14a of the heat utilization circulation circuit 14 is branched from between the upstream auxiliary hot water passage portion 24a and the downstream auxiliary hot water passage portion 24b. A hot water temperature detection sensor 24c capable of detecting the hot water temperature output from the auxiliary heat source unit 5 is installed in the upstream auxiliary hot water passage portion 24a, and a tank water proportional valve 32 is installed in the downstream auxiliary hot water passage portion 24b. Yes.

Next, the pouring passage 11 will be described.
The hot water supply passage 11 supplies hot water flowing through the hot water supply passage 21 to the bathtub, and is branched from the intermediate hot water supply passage portion 21b and the downstream hot water supply passage portion 21c on the downstream side of the hot water proportional valve 26. It is connected to the middle part of the bath memorial circuit 12. The pouring passage 11 is provided with a flow rate sensor 11a, a pouring electromagnetic valve 33, and the like.

Next, the bath memory circuit 12 will be described.
The bath chase circuit 12 is a circuit that circulates the bath water in order to chase the bathtub water in the bathtub, and has a bath return side passage portion 12a and a bath going side passage portion 12b. A bath circulation pump 36 is installed between the bath return side passage portion 12a and the bath going side passage portion 12b. The water flow switch 12c and the secondary heat exchange passage 6b of the bath heat utilization heat exchanger 6 are installed in the bath going side passage 12b.

Next, the hot water heating circuit 13 will be described.
The hot water heating circuit 13 is a circuit that circulates and supplies heating water supplied to the hot water heating terminal 10 such as a floor heating panel or a bathroom dryer, and is provided with a heating return passage portion 13a, a heating low-temperature forward passage portion 13b, and a heating high-temperature forward passage. It has a portion 13c. The heating return passage 13a is provided with an expansion tank 37 for absorbing the expansion of the heating water due to heating, and a heating circulation pump 38 for circulating the heating water. The secondary heat exchange passage portion 7b of the heating heat utilization heat exchanger 7 is installed in the heating high-temperature going passage portion 13c. A bypass thermal valve 39 is installed in the heating / low-temperature passage 13b.

  A high-temperature heating terminal 10A (for example, bathroom heating, a fan convector, etc.) is provided between the heating return passage 13a and the heating high-temperature passage 13c to circulate and supply heating water at about 80 ° C. A low temperature heating terminal 10B (for example, floor heating, a panel radiator, etc.) is provided between the heating return passage portion 13a and the heating low temperature passage portion 13b to circulate and supply heating water at about 60 ° C. Yes. During the heating operation, not only the high temperature heating terminal 10A or the low temperature heating terminal 10B but also the heating terminals 10 can be operated simultaneously.

  A heating replenishing water electromagnetic valve 37a is provided at the upper portion of the expansion tank 37, and a replenishing water passage portion 37b branched from the upstream water supply passage portion 8a of the water supply system passage 8 is connected to the heating replenishing water electromagnetic valve 37a. ing. When the heating replenishing water electromagnetic valve 37a is switched to the open state, the replenishing water is replenished to the expansion tank 37 through the replenishing water passage portion 37b. An overflow passage portion 37 c is connected to the upper portion of the expansion tank 37.

Next, the heat utilization circulation circuit 14 will be described.
The heat utilization circulation circuit 14 is a closed circuit that circulates hot water and performs heat exchange between the bath chase circuit 12 and the hot water heating circuit 13, and includes a hot water going-side passage portion 14a, a bath heat utilization passage portion 14b, and heating. It has a heat use passage 14c, a hot water return side passage 14d, a downstream heating passage 23b of the auxiliary heating passage 23, and an upstream auxiliary hot water passage 24a of the auxiliary heat source machine hot water passage 24. A primary heat exchange passage portion 6a of the bath heat utilization heat exchanger 6 and a bath heat utilization opening / closing valve 41 are installed in the bath heat utilization passage portion 14b, and the heating heat utilization heat exchanger 7 is disposed in the heating heat utilization passage portion 14c. Primary side heat exchange passage 7a and heating heat utilization opening / closing valve 42 are installed.

Next, the exhaust heat recovery circuit 15 will be described.
The exhaust heat recovery circuit 15 is a closed circuit that recovers the exhaust heat of the fuel cell power generator 2 by circulating hot water between the hot water storage tank 4 and the fuel cell power generator 2. It has a side circulation passage portion 15 b and the like, the upstream end is connected to the lower part of the hot water storage tank 4, and the downstream end is connected to the upper part of the hot water storage tank 4.

  A branch passage portion 15c connected to the high temperature side circulation passage portion 15b is branched from the low temperature side circulation passage portion 15a, and a circulation circuit including the hot water storage tank 4 and a circulation circuit bypassing the hot water storage tank 4 are selected in this branch portion. A three-way valve 43 that can be selectively selected is provided. Inside the fuel cell power generator 2, a circulation pump (not shown) is installed in the low temperature side circulation passage portion 15a, and fuel cell power generation is provided between the low temperature side circulation passage portion 15a and the high temperature side circulation passage portion 15b. An exhaust heat recovery unit (not shown) of the apparatus 2 is installed.

Next, the control unit 45 will be described.
The hot water supply / room heating device 3 is controlled by the control unit 45. The detection signals of various sensors are transmitted to the control unit 45, and the control unit 45 controls the operation of the hot water heater / heater 3, the operation / stop of various pumps, the switching of the open / close states of various valves, and the opening adjustment. Then, various operations (hot water supply operation, hot water filling operation, reheating operation, high temperature hot water supply operation, heating operation, freeze prevention operation, exhaust heat recovery operation, etc.) are performed.

  The control unit 45 can perform data communication with the operation remote controller 46 that can be operated by the user. When various operations are set by operating the switch of the operation remote controller 46, the command signal is transmitted from the operation remote controller 46 to the control unit 45. Sent to. For example, when the target hot water set temperature is set by operating the switch of the operation remote controller 46, the target hot water set temperature data is transmitted from the operation remote controller 46 to the control unit 45. The control unit 45 that performs the heating operation corresponds to the hot water heating control means.

Next, the heating operation related to the present invention will be described.
The control unit 45 has a plurality of modes that can be switched during the heating operation. That is, the control unit 45 performs the heating operation in the large combustion mode in which the combustion amount of the auxiliary heat source unit 5 is adjusted to be the most efficient according to the heating load of the hot water heating terminal 10, and the combustion amount lower than this large combustion mode. It is possible to perform a heating operation in a medium combustion mode for heating hot water and a heating operation in a hot water storage tank heat dissipation / radiation mode in which the hot water storage tank 4 is used as a hot hot water buffer. In addition, below, the case where the hot water supply and heating apparatus 3 performs the heating operation alone will be described.

Next, the large combustion mode will be described.
During the heating operation in the large combustion mode, the control unit 45 performs combustion using all or most of the plurality of combustion stages constituting the burner of the auxiliary heat source unit 5 and according to the heating load of the hot water heating terminal 10. The auxiliary heat source unit 5 is subjected to proportional combustion control or on / off combustion control. That is, if the heating load of the hot water heating terminal 10 is large and there is a temperature difference between the hot water temperature detected by the hot water temperature detection sensor 24c and the hot water temperature detected by the hot water temperature detection sensor 23e, the auxiliary heat source machine 5 The combustion of the auxiliary heat source machine 5 is combusted in accordance with the hot water temperature detected by the hot water temperature sensor 23e when the combustion load is controlled in a state where all or most of the combustion stages are used and the heating load becomes low. On-off combustion control. Specifically, in the on / off combustion control, the combustion is turned on when the hot water temperature detected by the hot water temperature detection sensor 23e is 45 degrees or less, for example, and the combustion is turned off when the hot water temperature is 60 degrees C or more.

Next, the middle combustion mode will be described.
During the heating operation in the middle combustion mode, the control unit 45 sets the combustion region narrower than the combustion region in the large combustion mode and wider than the non-combustion region, and also according to the heating load of the hot water heating terminal 10, the auxiliary heat source machine 5. Are controlled by proportional combustion control or on-off combustion control. That is, the control unit 45 performs combustion by reducing a plurality of combustion stages by a preset ratio (for example, about 40%) while maintaining the combustion region larger than the non-combustion region. Specifically, if the combustion amount becomes excessive even when the on / off combustion control is performed with the minimum combustion amount in the large combustion mode, the combustion stage is reduced (for example, changed from five-stage combustion to three-stage combustion) and the combustion quantity is reduced. In the state, the combustion of the auxiliary heat source unit 5 is controlled to be turned on / off.

  During the heating operation in the large combustion mode and the middle combustion mode, the control unit 45 switches the three-way valve 31 to a state in which the downstream heating passage portion 23b and the hot water return side passage portion 14d are connected, and the heating heat utilization opening / closing valve 42 is switched. The valve is switched to the open state, and the pressure pump 29 is driven.

  Then, as shown in FIG. 2, hot water flows into the auxiliary heat source unit 5 from the downstream heating passage portion 23b via the pressure feed pump 29, and the hot hot water heated by the auxiliary heat source unit 5 becomes the upstream auxiliary hot water. The hot water that flows through the passage portion 24a and the hot water going side passage portion 14a and is sent to the heating heat utilization passage portion 14c and exchanges heat with the heating water in the primary side heat exchange passage portion 7a is the hot water return side passage. It returns to the downstream heating passage part 23b through the part 14d.

Next, the hot water storage tank heat dissipation mode will be described.
During heating operation in the hot water storage tank heat dissipation mode, a part of the hot water output from the auxiliary heat source unit 5 is stored in the hot water storage tank 4 in the on period of the on / off combustion control while maintaining the number of combustion stages in the middle combustion mode. The temperature of the hot water flowing into the auxiliary heat source unit 5 is lowered by supplying low temperature hot water from the lower part of the hot water storage tank 4 to the heat utilization circulation circuit 14, and the hot water of the hot water storage tank 4 is turned off during the off period of the on / off combustion control. Is circulated and supplied to the heat exchanger 7 for heating.

  During the on period of the combustion on state in the on / off combustion control, the control unit 45 switches the tank water proportional valve 32 to the open state, and connects the three-way valve 31 between the downstream heating passage portion 23b and the hot water return side passage portion 14d. The heat storage switching valve 19 is switched to a state in which the downstream water supply passage portion 8c and the bypass passage portion 17 are connected, and the pressure pump 29 is driven.

  Then, as shown in FIG. 3, a part of the high-temperature hot water output from the auxiliary heat source machine 5 flows into the upper part of the hot water storage tank 4 through the downstream auxiliary hot water supply passage 24b and the tank hot water supply passage 22, and the hot water storage tank Low temperature hot water flows from the lower part of 4 through the downstream water supply passage portion 8c and the bypass passage portion 17 into the hot water return side passage portion 14d. In other words, in the combustion on state, the amount of heat supplied to the heating heat exchanger 7 is reduced without reducing the amount of combustion of the auxiliary heat source unit 5 by storing the excess amount of heat in the hot water storage tank 4. By mixing the low temperature hot water in the lower part of the tank 4 with the hot water returning from the heating heat exchanger 7, the temperature of the hot water returned to the auxiliary heat source unit 5 is lowered, so that the on period of the combustion on state can be extended.

  In the off period of the combustion off state in the on / off combustion control, the control unit 45 switches the tank water proportional valve 32 to the closed state, and moves the three-way valve 31 between the upstream heating passage portion 23a and the downstream heating passage portion 23b. The state is switched to the connection state, the heat storage switching valve 19 is maintained in a state where the downstream water supply passage portion 8c and the bypass passage portion 17 are connected, and the pressure pump 29 is driven.

  Then, as shown in FIG. 4, the hot hot water in the upper part of the hot water storage tank 4 flows into the stopped auxiliary heat source unit 5 through the upstream heating passage portion 23a and the downstream heating passage portion 23b, and the auxiliary heat source unit The hot water flowing out from 5 flows through the upstream auxiliary hot water passage portion 24a and the hot water forward passage portion 14a and is sent to the heating heat utilization passage portion 14c, and is heated between the heating water and the heating water in the primary heat exchange passage portion 7a. The exchanged hot water is returned to the lower part of the hot water storage tank 4 through the hot water return side passage portion 14d, the bypass passage portion 17, and the downstream water supply passage portion 8c. That is, in the combustion off state, the amount of heat stored in the hot water storage tank 4 is extracted, and this extracted heat amount is supplied to the heating heat exchanger 7 via the auxiliary heat source unit 5. The period can be extended.

  Next, heating operation control based on various modes automatically executed by the control unit 45 will be described based on the flowchart of FIG. In the figure, the symbol Si (i = 1, 2,...) Indicates each step. The control program for the heating operation control is stored in the control unit 45 in advance.

  In the flowchart of FIG. 5, when this control is started, first, in S1, it is determined whether or not the heating operation start condition is satisfied based on an input operation of the operation remote controller 46, detection of various temperature detection sensors, and the like. When the conditions for starting the heating operation are satisfied, that is, when the determination of S1 is Yes, the process proceeds to S2, and the control unit 45 sets the hot water heater 3 to the large combustion mode and performs the heating operation. Start (see FIG. 2), and the process proceeds to S3. If S1 is No, repeat S1.

  In addition, if the heating load of the hot water heating terminal 10 is reduced during the heating operation in the large combustion mode of S2, the temperature of the hot water returning to the auxiliary heat source unit 5 gradually increases, so that the hot water is kept at the minimum combustion amount of the proportional combustion control. Even if heated, the amount of combustion becomes excessive. Therefore, the combustion of the auxiliary heat source unit 5 is switched from proportional combustion control to on-off combustion control, and hot water is heated with a lower combustion amount. However, even if the on / off combustion control is performed, if the combustion amount becomes excessive, the combustion on / off operation is frequently repeated.

  Next, in S3, the control unit 45 determines whether or not a mode switching condition is satisfied. When the number of on / off combustion control on / off operations during the set period (for example, 1 hour) exceeds the set number (for example, 12 times), or when the cycle time for on / off combustion control falls below the set time (for example, 5 minutes), That is, when the determination in S3 is Yes, the process proceeds to S4, and the control unit 45 switches the heating operation from the large combustion mode to the middle combustion mode, and proceeds to S5. If S3 is No, repeat S3.

  In the heating operation in the middle combustion mode of S4, hot water is heated by reducing the combustion stage of the auxiliary heat source unit 5, but if the heating load of the hot water heating terminal 10 becomes extremely low, the combustion amount becomes excessive. Since the combustion on / off state is frequently repeated again, it is necessary to heat the hot water with a lower combustion amount. However, if the number of combustion stages (the number of combustion tubes) of the auxiliary heat source unit 5 is further reduced, the heat exchange efficiency deteriorates. To do. Therefore, as described below, a heating operation is performed in which the hot water storage tank 4 is used as a buffer for high-temperature hot water output from the auxiliary heat source unit 5.

  Next, in S5, the control unit 45 determines whether or not a mode switching condition is satisfied. When the number of on / off combustion control on / off combustion control exceeds the set number of times during the set period, or when one cycle of the on / off combustion control falls below the set time, that is, when the determination of S5 is Yes, the process proceeds to S6. The control unit 45 executes the heating operation by switching from the middle combustion mode to the hot water storage tank heat radiation mode, and proceeds to S7. If S5 is No, repeat S5.

  Next, in S7, the control unit 45 determines whether or not a predetermined condition is satisfied. This predetermined condition is, for example, when the heating load of the hot water heating terminal 10 is increased and the temperature of hot water flowing into the auxiliary heat source unit 5 is lowered. If the condition for returning to the large combustion mode is satisfied, that is, if the determination in S7 is Yes, the process proceeds to S2, and the control unit 45 changes the heating operation from the hot water storage tank heat dissipation mode to the large combustion mode. If the determination of S7 is No, S7 is repeated.

Next, the operation and effect of the hot water supply / room heating device 3 of the present invention will be described.
Since the control unit 45 switches from the large combustion mode to the medium combustion mode when the on / off number of the on / off combustion control during the set period exceeds the set number of times, or when one cycle of the on / off combustion control falls below the set time, Before the heating load of the hot water heating terminal 10 is low, one cycle time of the on / off combustion control is shortened, and the combustion on / off is frequently repeated, the combustion amount of the auxiliary heat source unit 5 is automatically reduced. be able to.

  Therefore, by reducing the combustion amount of the auxiliary heat source unit 5, it is possible to extend the ON period of the combustion ON state and extend one cycle time of the ON / OFF combustion control, and the repetition frequency of combustion ON / OFF is reduced. In addition, while preventing a decrease in durability of the auxiliary heat source unit 5 and setting the combustion range narrower than the combustion range in the large combustion mode and wider than the non-combustion range in the middle combustion mode, the heat exchange of the auxiliary heat source unit 5 An extreme reduction in efficiency can be prevented.

  Also, during heating operation in the hot water storage tank heat dissipation mode, during the ON period of the on / off combustion control, a part of the high temperature hot water output from the auxiliary heat source unit 5 is returned to the upper part of the hot water storage tank 4, and the lower temperature of the hot water storage tank 4 Since the temperature of the hot water flowing into the auxiliary heat source unit 5 is lowered by supplying the hot water to the heat utilization circuit 14, the on period of the combustion on state can be extended while maintaining the combustion amount of the auxiliary heat source unit 5. Since it is not necessary to make the combustion amount of the auxiliary heat source unit 5 extremely low, a stable combustion state can be maintained.

  Further, during the heating operation in the hot water storage tank heat dissipation mode, since the hot water in the hot water storage tank 4 is circulated and supplied to the heating heat exchanger 7 during the ON period of the on / off combustion control, the heating operation is performed. By preventing a rapid decrease in the hot water temperature, the off period of the combustion off state can be extended. That is, by using the hot water storage tank 4 as a high-temperature hot water buffer while maintaining the number of combustion stages in the middle combustion mode, it is possible to extend one cycle time of on-off combustion control.

  In addition, when the number of on / off combustion control on / off operations during the set period exceeds the set number of times, or when one cycle time of on / off combustion control falls below the set time, the control unit 45 stores the hot water storage tank from the middle combustion mode. Since switching to the heat dissipation mode is performed, when the combustion on / off of the on / off combustion control is frequently repeated in the middle combustion mode, the hot water storage tank 4 is used to automatically extend the control for one cycle time.

Next, a mode in which the above embodiment is partially changed will be described.
[1] In the above embodiment, the fuel cell power generator 2 has been described as an external heat source. However, the present invention is not limited to this, and a gas engine or the like may be employed. Can be adopted.

[2] In the above-described embodiment, the setting period, the number of times of setting, and the setting time are merely examples, and can be changed as appropriate. Similarly, if the reduction ratio of the combustion stage of the auxiliary heat source unit 5 is a ratio that can prevent the deterioration of the heat exchange efficiency by maintaining the combustion region narrower than the combustion region in the large combustion mode and wider than the non-combustion region, It can be changed as appropriate.

[3] In addition, those skilled in the art can implement the present invention in various forms with various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. It is.

DESCRIPTION OF SYMBOLS 3 Hot water supply and heating apparatus 4 Hot water storage tank 5 Auxiliary heat source machine 7 Heat exchanger 10 for heating Hot water heating terminal 13 Hot water heating circuit 14 Heat utilization circulation circuit 45 Control unit (hot water heating control means)

Claims (2)

A heat source circuit, a heat utilization circuit that circulates hot and cold water heated by combustion in the heat source apparatus, a hot water heating circuit that circulates heating water to an external hot water heating terminal, the heat utilization circulation circuit, and the hot water heating circuit. In a hot water supply and heating device equipped with a heat exchanger for heating that performs heat exchange between
During heating operation, combustion is performed using all or most of the plurality of combustion stages constituting the burner of the heat source unit, and the heat source unit is proportionally controlled or on-off combustion according to the heating load of the hot water heating terminal A large combustion mode to be controlled and a combustion region narrower than the combustion region of this large combustion mode and wider than the non-combustion region, and the heat source device is proportionally controlled or on-off combustion according to the heating load of the hot water heating terminal Comprising hot water heating control means having a medium combustion mode to control,
When the on / off combustion control on-off count during the set period exceeds the set number of times, or when one cycle time of the on-off combustion control falls below a set time, the hot water heating control means starts from the large combustion mode. A hot water supply and heating device, which is switched to a middle combustion mode. It has a hot water storage tank that can store hot water,
The hot water heating control means returns a part of high-temperature hot water output from the heat source unit to the upper part of the hot water storage tank during the ON period of the ON / OFF combustion control while maintaining the number of combustion stages in the medium combustion mode. The hot water flowing into the heat source unit is lowered by supplying low temperature hot water from the lower part of the hot water storage tank to the heat utilization circulation circuit, and the hot water in the hot water storage tank is heated during the off period of the on-off combustion control. It has a hot water storage tank heat dissipation mode that circulates and supplies heat to the heat exchanger for heating,
The hot water heating control means, when the number of on / off of the on / off combustion control during a set period exceeds the set number of times, or when one cycle time of the on / off combustion control falls below a set time, from the middle combustion mode The hot water supply and heating device according to claim 1, wherein the hot water storage tank is switched to a heat storage and heat dissipation mode.