JP2019007650A - Heat source apparatus - Google Patents

Abstract

To prevent freezing of a fluid passage in a combustion system in which a combustion operation is not carried out in cases where there are a combustion system in which the combustion operation is carried out and the combustion system in which the combustion operation is not carried out.SOLUTION: In cases where a combustion operation is carried out in one combustion system 40 and the combustion operation is not carried out in another combustion system 30, a maximum number of rotations of a blower fan 70 that supplies combustion air to the combustion system 30 in which the combustion operation is carried out, is limited to a maximum number of rotations during freezing which is lower than the maximum number of rotations, when a fluid temperature of a fluid passage in the other combustion system 40 becomes lower than a predetermined reference temperature.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat source device having a plurality of combustion systems. In particular, the present invention relates to prevention of freezing of a fluid flow path in a combustion system in which the combustion operation is not performed when there are a combustion system in which the combustion operation is performed and a combustion system in which the combustion operation is not performed.

  Heat source devices such as a hot water supply device with a heating function, a hot water supply device with a reheating function, a hot water supply device with a reheating function and a reheating function, heat that heats and heats a fluid such as water or a heat medium flowing through a fluid flow path. A plurality of combustion systems each having an exchanger are provided. In this type of heat source device, a single can body is partitioned into a plurality of partitions, and a burner unit and a heat exchanger are disposed in each partition portion, or a can body in which each burner unit and a heat exchanger are accommodated. It is configured by combining multiple items. Further, in these heat source devices, when an individual blower fan corresponding to each combustion system is provided as a blower fan for supplying combustion air to the burner unit, or a common blower fan for a plurality of combustion systems is provided. May be provided.

  In a heat source device having a plurality of combustion systems as described above, an anti-freezing operation is performed in winter to prevent freezing of the fluid flow path of each combustion system. For example, in a hot water supply device with a heating function, an outside air temperature sensor that detects the outside air temperature is provided, and when the outside air temperature falls below a predetermined freezing danger temperature, a combustion operation is performed in the combustion system on the heating side, and fluid is supplied to the fluid flow path. When the combustion operation is performed in the hot water supply side combustion system during the intermittent suspension of the freeze prevention operation, the fluid is circulated through the fluid flow path of the heating side combustion system to thereby provide the fluid in the heating side combustion system. Freezing of the flow path is prevented (for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-9593

  By the way, a heat source device having a plurality of combustion systems is a large-sized device, and a local temperature is different in the device. Therefore, depending on the position where the outside air temperature sensor is provided, the possibility of freezing based on the outside air temperature may not necessarily coincide with the possibility of freezing the fluid flow path in each combustion system. In addition, when a combustion operation is started in another combustion system after a short time has elapsed after the combustion operation is completed in one combustion system, the combustion operation is not performed even if the outside air temperature is lower than the freezing danger temperature. The possibility of freezing the fluid flow path of the combustion system is low. Therefore, there is a problem that the possibility of freezing the fluid flow path in the combustion system in which the combustion operation in which freezing is actually likely to occur is not performed can be appropriately determined only by the outside air temperature detected by the outside air temperature sensor.

  Further, in a heat source device in which a plurality of combustion systems are housed in a single can body, or a heat source device in which a plurality of can bodies in which each combustion system is housed is provided in one housing, one combustion system When the blower fan is rotated in order to perform the combustion operation, low temperature air also flows into other combustion systems that are not performing the combustion operation, thereby cooling the fluid flow path. In particular, in a case where a plurality of combustion systems use a common exhaust path or a common air supply path, such as a forced exhaust type or forced supply / exhaust type heat source device, combustion operation is performed by air flowing in from other combustion systems. Freezing is likely to occur in the fluid flow path of the combustion system that is not known.

  The present invention solves the above problems, and an object of the present invention is, in a heat source device having a plurality of combustion systems, a combustion system in which combustion operation is performed and a combustion system in which combustion operation is not performed. In some cases, the fluid flow path in the combustion system in which the combustion operation is not performed is efficiently prevented from freezing.

According to the present invention,
A burner unit having a burner, a heat exchanger that heat-exchanges and heats a fluid that flows through a fluid flow path by combustion exhaust generated by the burner unit, and at least one fluid temperature detection unit that detects the temperature of the fluid flowing in the fluid flow path A plurality of combustion systems each having
A blower fan that supplies combustion air to one or more combustion system burner units;
A control device for performing normal combustion control for controlling the target rotational speed of the blower fan at a predetermined maximum rotational speed or less in accordance with the required combustion amount required for the burner unit of the combustion system performing the combustion operation,
This is a heat source device in which air flows into other combustion systems that are not operating by rotating the blower fan to supply combustion air to the burner unit of the combustion system that is performing the combustion operation. And
When the combustion operation is performed in at least one combustion system and the combustion operation is not performed in the other combustion system, the control device is detected by the fluid temperature detection unit of the other combustion system in which the combustion operation is not performed. When the fluid temperature is lower than the predetermined reference temperature, the target rotational speed of the blower fan that supplies combustion air to the combustion system in which the combustion operation is performed is lower than the maximum rotational speed when the target rotational speed is lower than the maximum rotational speed. A heat source device is provided that restricts to

  According to the heat source device, when the combustion operation is performed in at least one combustion system and the combustion operation is not performed in another combustion system, the fluid temperature detection unit of the other combustion system in which the combustion operation is not performed Therefore, it is possible to determine whether the fluid flow path of the combustion system in which the combustion operation is not performed can be frozen more accurately.

  According to the heat source device, the target rotational speed of the blower fan is controlled to be equal to or lower than the predetermined maximum rotational speed in accordance with the required combustion amount required for the burner unit performing the combustion operation, and there is a possibility of freezing. In this case, the target rotational speed of the blower fan that supplies the combustion air to the combustion system in which the combustion operation is performed is limited to the maximum rotational speed during freezing that is lower than the maximum rotational speed. Thus, the inflow of air to other combustion systems that are not performing the combustion operation is suppressed, and the possibility of freezing the fluid flow paths of other combustion systems can be reduced.

Preferably, the heat source device further includes:
It has an outside air temperature detector that detects the outside air temperature,
The control device is configured such that the outside air temperature detected by the outside air temperature detecting unit is lower than a predetermined freezing danger temperature and the fluid temperature detected by the fluid temperature detecting unit of another combustion system in which the combustion operation is not performed is the predetermined temperature. When the temperature is lower than the reference temperature, the target rotational speed of the blower fan that supplies the combustion air to the combustion system in which the combustion operation is performed is limited to the maximum rotational speed during freezing that is lower than the maximum rotational speed.

  According to the heat source device, not only the fluid temperature becomes lower than the reference temperature, but also whether or not the outside air temperature is lower than a predetermined freezing danger temperature is determined, so that the possibility of freezing can be determined more accurately.

Preferably, in the heat source device,
The burner unit of at least one combustion system among the plurality of combustion systems has a plurality of capacity stages having different combustion amount ranges,
When the combustion operation is performed in a combustion system including a burner unit having a plurality of capacity stages, the control device has a lower combustion amount range on the low combustion amount side and an upper combustion amount range on the high combustion amount side adjacent thereto. In between, the normal combustion control is performed to switch and control the number of capacity stages using the overlap margin provided so that the maximum combustion amount in the lower combustion amount range is larger than the minimum combustion amount in the upper combustion amount range. ,
Fluid temperature detection in other combustion systems where combustion operation is performed when a combustion system is equipped with a burner unit having a plurality of capacity stages and combustion operation is not performed in another combustion system When the fluid temperature detected by the unit becomes lower than the predetermined first reference temperature, the target rotational speed of the blower fan that supplies the combustion air to the burner unit of the combustion system in which the combustion operation is performed is increased from the maximum rotational speed. It is limited to a predetermined reduction amount that falls within the range of the overlap allowance with the side combustion amount range, or lower than the reduced maximum rotation speed during freezing.

  In a burner unit having a plurality of capacity stages in order to expand the adjustable range of the combustion quantity, combustion is performed in such a manner that the capacity stage is increased by one when the required combustion quantity becomes larger than the maximum combustion quantity in the combustion quantity range at the predetermined capacity stage number. When the operation is performed and the required combustion amount becomes smaller than the minimum combustion amount in the combustion amount range of the predetermined number of capability stages, the combustion operation is performed in a manner that the number of capability stages is decreased by one. Therefore, the maximum combustion amount in the lower combustion amount range on the low combustion amount side is between the lower combustion amount range on the lower combustion amount side and the upper combustion amount range on the higher combustion amount side adjacent thereto. By switching the number of capacity stages using the overlap allowance, a regular overlap control is provided so that the combustion amount is larger than the minimum combustion amount in the upper combustion range of the engine. Hunting due to is prevented.

  Therefore, when the combustion operation is performed in the combustion system including the burner units having a plurality of capability stages having different combustion amount ranges and the combustion operation is not performed in the other combustion systems, the fluid temperature is a predetermined first reference. If the temperature is lower than the temperature and there is a possibility of freezing, the target rotational speed of the blower fan is within the range of the overlap allowance with the upper combustion amount range reduced by a predetermined reduction amount from the maximum rotational speed in normal combustion control. By limiting the number of revolutions to below the maximum rotation speed during freezing, the number of capacity stages is maintained even if the combustion amount within the range of overlap is required, so hunting of the burner unit in the combustion system in which combustion operation is performed is suppressed. However, it is possible to prevent freezing of other combustion systems that are not performing the combustion operation.

Preferably, in the heat source device,
The burner unit of at least one combustion system among the plurality of combustion systems has a plurality of capacity stages having different combustion amount ranges,
When the combustion operation is performed in a combustion system including a burner unit having a plurality of capacity stages, the control device has a lower combustion amount range on the low combustion amount side and an upper combustion amount range on the high combustion amount side adjacent thereto. In between, the normal combustion control is performed to switch and control the number of capacity stages using the overlap margin provided so that the maximum combustion amount in the lower combustion amount range is larger than the minimum combustion amount in the upper combustion amount range. ,
Fluid temperature detection in other combustion systems where combustion operation is performed when a combustion system is equipped with a burner unit having a plurality of capacity stages and combustion operation is not performed in another combustion system When the fluid temperature detected by the unit becomes lower than the predetermined second reference temperature, the target rotational speed of the blower fan that supplies the combustion air to the burner unit of the combustion system in which the combustion operation is performed is set to be higher than the maximum rotational speed. It is limited to a fixed maximum freezing rotation speed that is lower than the range of the overlap allowance with the lower upper combustion amount range.

  As described above, in a combustion system including a burner unit having a plurality of capacity stages, between a lower combustion amount range on the low combustion amount side and an upper combustion amount range on the high combustion amount side adjacent thereto, Hunting is prevented by providing overlap allowance so that the maximum combustion amount in the lower combustion amount range is larger than the minimum combustion amount in the upper combustion amount range, and switching the number of capacity stages using the overlap allowance. .

  Further, when the fluid temperature detected by the fluid temperature detection unit becomes lower than the predetermined second reference temperature and the possibility of freezing increases, the combustion operation is performed by further reducing the maximum rotational speed of the blower fan. While it is possible to reduce the air that flows into other combustion systems that are not known, the lower side of the lower stage that can be used by arbitrarily reducing the rotational speed of the fan corresponding to the combustion amount lower than the range of overlap with the upper side combustion amount range A large combustion amount difference occurs between the combustion amount range and the upper combustion amount range, and frequent switching of the number of capacity steps occurs.

  However, according to the above heat source device, when the fluid temperature decreases and the possibility of freezing increases, the combustion air is supplied to the burner unit when burning the burner unit of the combustion system in which the combustion operation is performed. The target rotational speed of the blower fan to be performed is limited to a fixed freezing maximum rotational speed that is lower than the maximum rotational speed and is equal to or less than the range of the overlap allowance with the upper stage combustion amount range. Therefore, when the burner unit is burned in the lower combustion amount range, the capacity stage number is maintained until the minimum combustion amount in the upper combustion amount range is required. On the other hand, when the burner unit is burned in the upper combustion range, the burner unit is in the upper combustion range until a combustion amount corresponding to the maximum rotation speed during freezing in which the lower combustion range is fixed is required. The number of capacity stages is maintained by burning with the minimum amount of combustion. Thereby, it is possible to more reliably prevent freezing of other combustion systems that are not performing the combustion operation while suppressing hunting as much as possible.

  As described above, according to the present invention, in a heat source device having a plurality of combustion systems, when there are a combustion system in which the combustion operation is performed and a combustion system in which the combustion operation is not performed, there is actually freezing. Since the possibility of freezing is determined based on the fluid temperature of the fluid flow path in the combustion system in which the combustion operation that is likely to occur is not performed, the possibility of freezing can be predicted more accurately. According to the present invention, when there is a possibility of freezing, when the target rotational speed of the blower fan that supplies the combustion air to the combustion system in which the combustion operation is performed is reduced below the maximum rotational speed Since the maximum number of rotations is limited, it is possible to suppress the inflow of air to other combustion systems in which the combustion operation is not performed by rotating the blower fan. Thereby, freezing of the fluid flow path of the combustion system in which the combustion operation is not performed can be effectively prevented.

FIG. 1 is a schematic configuration diagram illustrating an example of a heat source device according to an embodiment of the present invention. FIG. 2 is a correlation diagram showing an example of the relationship between the amount of combustion of the burner unit of the heat source device according to the embodiment of the present invention and the number of fan rotations. FIG. 3 is a data table showing an example of setting values for reducing the maximum rotational speed of the blower fan when there is a possibility of freezing in the heat source device according to the embodiment of the present invention. FIG. 4 is a flowchart showing an example of the control operation of the heat source device according to the embodiment of the present invention.

  Hereinafter, the heat source device according to the embodiment of the present invention includes a hot water supply operation for supplying hot water to a hot water supply terminal such as a curan provided in a bathroom, a reheating operation for heating hot water in a bathtub, and a hot water heating terminal ( An example will be described in which the present invention is applied to a heating and hot water supply device with a replenishment function that performs a heating operation that circulates and supplies hot water to a floor heater, a hot air heater, and the like.

  FIG. 1 is a schematic configuration diagram illustrating an example of a heat source device according to an embodiment of the present invention. The heat source device 1 is installed in an indoor basement, for example, in a housing 10 that communicates with the outside via a supply cylinder 6 connected to an intake port 5 and an exhaust cylinder 8 connected to an exhaust port 7. This is a forced supply / exhaust heat source device in which a can body 20 having two combustion systems is disposed. The inside of the can body 20 is partitioned by a partition portion 21, and includes a hot water supply side combustion system 30 and a heating / reheating side combustion system 40.

  In the hot water supply side combustion system 30, a hot water supply side burner unit 33, a hot water supply side first heat exchanger 31, and a hot water supply side second heat exchanger 32 are arranged in this order from the bottom. The hot water supply side first heat exchanger 31 recovers sensible heat from the combustion exhaust discharged from the hot water supply side burner unit 33, and the hot water supply side second heat exchanger 32 is recovered from the combustion exhaust discharged from the hot water supply side burner unit 33. Recover latent heat.

  The hot water supply side combustion system 30 is connected to the water supply as a fluid flow path, connected to the upstream end of the hot water supply side second heat exchanger 32, the downstream end of the hot water supply side second heat exchanger 32, and the hot water supply. A hot water supply path 100 connected to the downstream end of the hot water supply side first heat exchanger 31, a connection path 95 connecting the upstream end of the first hot heat exchanger 31, a hot water supply terminal P 1 such as a currant, and the water supply A hot water supply bypass passage 105 that bypasses the passage 90 and the hot water supply passage 100 is provided. With this configuration, water supplied from the water supply to the water supply passage 90 is heat-exchanged and heated by the hot water supply side second heat exchanger 32 and the hot water supply side first heat exchanger 31 by the combustion exhaust discharged from the hot water supply side burner unit 33. The heated hot water is supplied to the hot water supply terminal P1 through the hot water supply path 100. In addition, the freezing prevention heaters 400 and 401 are provided in the connecting path 95 that connects the hot water supply side first heat exchanger 31 and the hot water supply side second heat exchanger 32.

  The hot water supply path 100 is supplied to the downstream side from the junction of the hot water temperature sensor 101 for detecting the temperature of hot water discharged from the hot water supply side first heat exchanger 31 and the hot water supply bypass path 105 in order from the upstream side. A hot water temperature sensor 103 for detecting the temperature of the hot water is provided. The temperature of the hot water detected by these temperature sensors 101 and 103 is output to the control circuit C1 described later. Therefore, the heat exchanger temperature sensor 101 and the hot water temperature sensor 103 function as a fluid temperature detector that detects the temperature of the fluid flowing through the fluid flow path in the hot water supply side combustion system 30. Furthermore, the hot water supply path 100 is provided with heaters 403 and 405 for preventing freezing.

  A blower fan 70 is provided below the hot water supply side burner unit 33, and outdoor air sucked into the housing 10 from the air supply port 5 by the operation of the blower fan 70 is supplied to the hot water supply side burner unit 33 and While being supplied as combustion air to a heating side burner unit 43 which will be described later, combustion exhaust discharged from the hot water supply side burner unit 33 and the heating side burner unit 43 is discharged from the exhaust port 7. A blower fan may also be provided below the heating side burner unit 43 to supply combustion air to the hot water supply side burner unit 33 and the heating side burner unit 43 individually.

  The hot water supply side burner unit 33 includes three hot water supply side burner blocks 33a, 33b, and 33c each having a plurality of burners, and each hot water supply side burner block 33a, 33b, and 33c is connected to a gas supply path (not shown). The branched hot water supply side gas branch 52 is connected. An original electromagnetic valve 51 for opening and closing the gas supply path is provided in the gas supply path. The hot water supply side gas branch 52 is individually switched between the hot water supply side gas proportional valve 53 for changing the opening degree of the hot water supply side gas branch 52 and the supply and shutoff of the fuel gas to the hot water supply side burner blocks 33a, 33b and 33c. Hot water supply side switching valves 54a, 54b, 54c are provided. Therefore, by selectively opening and closing the hot water supply side switching valves 54a, 54b, 54c, the hot water supply side burner unit 33 is switched to one of the capacity stages having different combustion amount ranges.

  The water supply channel 90 communicates with a water amount sensor 91 that detects the flow rate of water flowing through the water supply channel 90, a water amount servo 92 that changes the opening of the water supply channel 90, and the water supply channel 90 and the hot water supply channel 100 in order from the upstream side. A bypass servo 93 for changing the opening degree of the hot water supply bypass passage 105 is provided. Further, the water supply passage 90 is provided with heaters 402, 404, and 406 for preventing freezing.

  Further, a hot water filling passage 250 branches from the hot water supply passage 100, and the hot water filling passage 250 communicates with a bath return passage 251 connected to the bathtub P2. The bath return path 251 constitutes a circulation circuit between the bathtub P <b> 2 and the bath heat exchanger 221 together with the bath going-out path 252.

  In the hot water passage 250, a hot water solenoid valve 261 that opens and closes the hot water passage 250 in order from the upstream side, a check valve 263 for preventing a back flow of hot water from the hot water passage 250 to the hot water supply passage 100, A hot water quantity sensor 262 that detects the flow rate of hot water supplied from the hot water supply path 100 to the hot water supply path 250 is provided. Further, the hot water filling path 250 is provided with a heater 407 for preventing freezing.

  The bath return path 251 circulates the bath return temperature sensor 225 that detects the temperature of hot water flowing into the bath return path 251 from the bathtub P2 and the hot water in the bathtub P2 through the bath return path 252 and the bath return path 251. Bath pump 224, a water level sensor 223 that detects the level of hot water in the bathtub P2, and a bath water flow switch 222 that detects that hot water of a predetermined flow rate or more is flowing in the bath return path 251. . In addition, the bath going-out path 252 is provided with a bath going-out temperature sensor 226 that detects the temperature of the hot water flowing out from the bath heat exchanger 221 to the bathtub P2. Furthermore, the bath pump 224 is provided with a heater 408 for preventing freezing.

  In the heating / heating-side combustion system 40, a heating-side burner unit 43, a heating-side first heat exchanger 41, and a heating-side second heat exchanger 42 are arranged in order from the bottom. The heating-side first heat exchanger 41 collects sensible heat from the combustion exhaust discharged from the heating-side burner unit 43, and the heating-side second heat exchanger 42 recovers from the combustion exhaust discharged from the heating-side burner unit 43. Recover latent heat.

  The heating / heating-side combustion system 40 is connected as a fluid flow path to the heating return path 200 connected to the upstream end of the heating-side second heat exchanger 42 and to the downstream end of the heating-side first heat exchanger 41. The heating outbound path 210 and the communication outbound path 205 and the communication return path 206 that connect the downstream end of the heating side second heat exchanger 32 and the upstream end of the heating side first heat exchanger 41 with the cistern 201 interposed therebetween. Prepare.

  The cistern 201 branches from the water supply channel 90 and is connected to a hydration channel 204 for replenishing the cistern 201 with water. A water replenishing electromagnetic valve 203 is provided at a connection portion between the systern 201 and the water replenishment channel 204, and water introduced from the water supply to the water supply channel 90 is supplied by opening the water replenishing electromagnetic valve 203. In addition, a heater 409 for preventing freezing is provided in the supplemental water channel 204.

  The heating outbound path 210 is connected to a high temperature heating terminal (hot air heating terminal or the like) P3. The communication return path 206 is provided with a heating pump 211 for circulating hot water between the high temperature heating terminal P3 and the heating / reheating side combustion system 40. In addition, a low temperature branch 216 branches from an intermediate portion downstream of the heating pump 211 to the communication return path 206, and is connected to a thermal valve header 212 for connecting a low temperature heating terminal (floor heating or the like) P4. . Further, a heating return path 217 for returning hot water from the low temperature heating terminal P4 is connected to the heating return path 200. With this configuration, by operating the heating pump 211, hot water flowing through the heating return path 200 is heated by the combustion exhaust discharged from the heating-side burner unit 43, and the heating-side second heat exchanger 42 and the heating-side first heat exchanger. In 41, heat exchange heating is performed, and the heated hot water is circulated and supplied from the heating outbound path 210 to each of the heating terminals P3 and P4.

  A heating high temperature sensor 213 for detecting the temperature of hot water discharged from the heating side first heat exchanger 41 is provided in the heating outbound path 210, and the communication outbound path 206 is connected to the low temperature branch path 216 from the systern 201. And a heating low-temperature sensor 215 for detecting the temperature of the hot and cold water supplied to the water. The temperature of the hot water detected by these temperature sensors 213 and 215 is output to the control circuit C1 described later. Therefore, the heating high temperature sensor 213 and the heating low temperature sensor 215 function as a fluid temperature detector that detects the temperature of the fluid flowing through the fluid flow path in the heating / reheating-side combustion system 40.

  The heating-side burner unit 43 is composed of two burner blocks 43a and 43b each having a plurality of burners, and each of the burner blocks 43a and 43b is connected to a heating-side gas branch path 60 branched from the gas supply path. Has been. The heating-side gas branch path 60 includes a heating-side gas proportional valve 61 that changes the opening degree of the heating-side gas branch path 60 and a heating-side switching valve that individually switches between supply and shutoff of fuel gas to the burner blocks 43a and 43b. 62a and 62b are provided. Therefore, by selectively opening and closing the heating side switching valves 62a and 62b, the heating side burner unit 43 is switched to one of the capability stages having different combustion amount ranges.

  The bath heat exchanger 221 described above is provided in the middle of the bath branch path 240 branched from the heating outbound path 210. In the bath heat exchanger 221, heat exchange (liquid-liquid heat exchange) is performed between the hot water flowing in the bath going path 252 and the hot water flowing in the bath branching path 240, and flows in the bath going path 252. The hot water is heated. The bath branch path 240 is provided with an additional flow control valve 220 that changes the opening degree of the bath branch path 240.

  An outside air temperature sensor 11 that detects the temperature of air (outside air) that flows in from the outside via the supply cylinder 6 is provided in the vicinity of the air inlet 5. The outside air temperature detected by the outside air temperature sensor 11 is output to the control circuit C1. Therefore, the outside air temperature sensor 11 functions as an outside air temperature detecting unit that detects the outside air temperature. Note that the outside air temperature sensor 11 may be provided outdoors or may be provided in another location of the housing 10.

  A remote controller 301 is connected to the control circuit C1 incorporated in the housing 10, and the user operates the remote controller 301 to operate the hot water supply temperature in the hot water supply operation, the hot water temperature in the hot water operation, and the heating operation. The heating temperature, the reheating temperature in the renewal operation, and the like can be set. Although not shown, the control circuit C1 includes a fan motor of the blower fan 70, an original solenoid valve 51, a hot water supply side gas proportional valve 53, a hot water supply side switching valve 54a, 54b, 54c, a heating side gas proportional valve 61, and a heating side. An ignition electrode that sparks in the vicinity of each flame hole of the switching valves 62a and 62b, the hot water supply side burner unit 33, and the heating side burner unit 43, a flame detection sensor that detects ignition of the hot water supply side burner unit 33 and the heating side burner unit 43, Water volume sensor 91, water volume servo 92, bypass servo 93, water filling solenoid valve 203, hot water solenoid valve 261, hot water volume sensor 262, additional flow control valve 220, heating pump 211, bath water flow switch 222, water level sensor 223, bath Pump 224, water level electrode of cistern 201, heat exchange temperature sensor 101, hot water temperature sensor 103, heating high temperature temperature sensor 213, heating low temperature sensor 215, the outside air temperature sensor 11, the bath return temperature sensor 225, a bath forward temperature sensor 226, heater 401 to 409 for antifreeze is connected through an electric wire.

  The control circuit C1 is an electronic circuit unit configured by a CPU, a memory, an interface circuit, and the like (not shown), and the control program for the heat source device 1 stored in the memory is executed by the CPU, whereby the overall control of the heat source device 1 is performed. It functions to control the operation. Further, in the memory of the control circuit C1, the fuel gas supply amount for obtaining the required combustion amount required in each burner unit 33, 43 and the fuel gas supply amount when performing various operations in each combustion system 30, 40 A data table including a set value of the target rotational speed of the blower fan 70 corresponding to the above and a data table for reducing the maximum rotational speed of the blower fan 70 described later are stored.

  For example, the heating operation in the heating / heating-side combustion system 40 will be described. The control circuit C1 uses the heating-side burner unit 43 in accordance with the hot water temperature detected by the heating high temperature sensor 213 and the heating low temperature sensor 215. By calculating the required required combustion amount and controlling the opening degree of the heating side gas proportional valve 61 and the opening and closing of the heating side switching valves 62a and 62b so as to obtain the required required combustion amount, the fuel gas The supply amount (combustion amount) is controlled, and the target rotational speed of the blower fan 70 is controlled so as to be the supply amount of combustion air corresponding to the fuel gas supply amount, and normal combustion control is executed. ing.

  Here, as described above, the heating-side burner unit 43 of the present embodiment has a plurality of capacity stages having different combustion amount ranges, and the normal combustion control of the heating-side burner unit 43 is shown in FIG. It is configured to be executed based on the correlation between the combustion amount and the fan rotation speed of the blower fan 70.

  Specifically, in the normal combustion control, the first combustion side range G1 on the low combustion amount side for burning only the burner block 43a and the first burner blocks 43a and 43b for burning only the burner block 43a according to the required combustion amount. The second stage combustion amount range G2 on the higher combustion amount side than the stage side combustion amount range G1 is selectively switched and executed. Thereby, the combustion amount can be adjusted in a wide combustion amount range from the first stage to the second stage. Therefore, as understood from FIG. 2, in the heating-side burner unit 43, the first stage combustion amount range G1 corresponds to the lower combustion amount range on the low combustion amount side, and the second stage combustion amount range G2 is Corresponds to the upper combustion amount range of the high combustion amount side. When there are three or more capacity stages, the middle capacity stage corresponds to the upper stage with respect to the lower capacity stage, and the higher capacity stage with respect to the higher capacity stage. Corresponds to the lower side.

  The target rotational speed of the blower fan 70 corresponds to the first stage side and second stage side minimum combustion amounts G1p, G2p and the first stage side and second stage side maximum combustion amounts G1q, G2q of each capacity stage number. The first stage side and second stage side minimum rotational speeds R1p and R2p and the first stage side and second stage side maximum rotational speeds R1q and R2q are set so that a predetermined amount of combustion air is supplied. The first stage maximum rotational speed R1q corresponding to the first stage maximum combustion amount G1q is set higher than the second stage maximum rotational speed R2q corresponding to the second stage maximum combustion amount G2q. For this reason, in the normal combustion control of the heating side burner unit 43, the first stage side maximum rotational speed R1q corresponds to the maximum rotational speed of the blower fan 70. Further, as shown in FIG. 2, the first stage maximum combustion amount G1q of the first stage side combustion amount range G1 is larger than the second stage minimum combustion amount G2p of the second stage side combustion amount range G2. Is set to Thereby, the overlap amount of the combustion amount range is provided between the adjacent capability stages.

  Therefore, the case where the capacity stage number is switched in the direction of increasing the combustion amount as the required combustion amount increases will be described. In the combustion state in which only the heating side switching valve 62a is opened and only the burner block 43a is combusted. Based on the first characteristic line L1, the opening degree of the heating side gas proportional valve 61 is increased so as to increase the combustion amount in the first stage side combustion amount range G1, and the blower fan 70 is correspondingly increased. Increase the target speed. When the required combustion amount becomes the first stage side maximum combustion amount G1q and the blower fan 70 is rotated at the first stage side maximum rotation speed R1q, the heating side switching valve 62b is further opened, and both burner blocks 43a are opened. 43b are burned. At this time, the amount of fuel gas supplied to the entire heating-side burner unit 43 is increased, but the amount of fuel gas supplied to each of the burner blocks 43a and 43b is decreased. Decrease the number. Then, as the required combustion amount further increases, the opening degree of the heating-side gas proportional valve 61 is increased in order to increase the combustion amount in the second stage combustion amount range G2 based on the second characteristic line L2, The target rotational speed of the blower fan 70 is increased. The first stage side and second stage side minimum combustion amounts G1p and G2p, and the first stage side and second stage side maximum combustion amounts G1q and G2q are used for the combustion capacity and the number of capacity stages of the heating side burner unit 43. It can be appropriately selected based on the characteristics of the burner.

  On the other hand, a description will be given of a case where the capacity stage number is switched in the direction of decreasing the combustion amount as the required combustion amount decreases. The heating-side switching valves 62a and 62b are opened, and both the burner blocks 43a and 43b are burned. In order to reduce the combustion amount based on the second characteristic line L2 from the combustion state, the opening degree of the heating side gas proportional valve 61 is decreased and the target rotational speed of the blower fan 70 is decreased accordingly. Go. When the required combustion amount becomes the second stage side minimum combustion amount G2p and the blower fan 70 is rotated at the second stage side minimum rotation speed R2p, the heating side switching valve 62b is closed and only the burner block 43a is closed. Burn. At this time, the amount of fuel gas supplied to the entire heating-side burner unit 43 is reduced, but the amount of fuel gas supplied to the burner block 43a is increased, so that the target rotational speed of the blower fan 70 is increased accordingly. . Further, as the required combustion amount decreases, the opening degree of the heating-side gas proportional valve 61 is decreased and the target rotational speed of the blower fan 70 is decreased so as to decrease the combustion amount based on the first characteristic line L1. Go. Note that the hot water supply side burner unit 33 has a different number of capacity stages with different combustion amount ranges from the heating side burner unit 43, but the capacity number switching is the same as described above.

  Thus, the maximum combustion amount in the lower combustion amount range on the low combustion amount side is set to be larger than the minimum combustion amount in the upper combustion amount range on the high combustion amount side adjacent to the lower combustion amount range. By providing an overlap margin with the side combustion amount range, frequent switching of the number of capability stages of the burner units 33 and 43 is prevented, the combustion state is stabilized, and hunting is prevented.

  By the way, in the heat source device 1 as described above, there is a possibility that the hot water in each fluid flow path is frozen in winter, but the possibility of freezing based on the outside air temperature and the possibility of freezing based on the temperature of the hot water are not necessarily the same. May not. For example, when the combustion operation is performed in one heating side / reheating combustion system 40 and the combustion operation is not performed in the other hot water supply side combustion system 30, the blower fan 70 is rotated to perform the combustion operation. Then, air flows into the hot water supply side combustion system 30 where the combustion operation is not performed, so that the hot water in the fluid flow path is easily frozen. In particular, the plurality of combustion systems 30, 40 are disposed in the same can body 20 having the common supply cylinder 6 and the exhaust cylinder 8, and the combustion air is supplied by the common blower fan 70. The possibility increases.

  For this reason, in the heat source device 1 of the present embodiment, the combustion operation is performed in the heating side / reheating combustion system 40, but when the combustion operation is not performed in the hot water supply side combustion system 30, the outside air temperature sensor 11. The possibility of freezing is determined not only based on the outside air temperature detected in step 1 but also on the temperature of hot water detected by the heat exchanger temperature sensor 101 and the hot water temperature sensor 103. If there is a possibility of freezing, The maximum rotational speed of the blower fan 70 is reduced according to the temperature and the temperature of the hot water. Further, when the combustion operation is performed in the hot water supply side combustion system 30, but the combustion operation is not performed in the heating side / reheating combustion system 40, similarly, only the outside air temperature detected by the outside air temperature sensor 11 is used. However, the possibility of freezing is determined based on the temperature of hot water detected by the heating high temperature sensor 213 and the heating low temperature sensor 215, and if there is a possibility of freezing, depending on these outside air temperature and hot water temperature The maximum rotational speed of the blower fan 70 is reduced.

  For example, when a heating operation is performed in the heating / reheating side combustion system 40 and a hot water supply operation is not performed in the hot water supply side combustion system 30, the outside air temperature Th detected by the outside air temperature sensor 11 and the heat exchange temperature sensor 101 are detected. Based on the detected hot water temperature Ta and the hot water temperature Tb detected by the tapping temperature sensor 103, the possibility and the degree of freezing of the fluid flow path of the hot water supply side combustion system 30 where the hot water supply operation is not performed are determined. If there is a possibility of freezing based on the data table shown in FIG. 3, the heating-side burner unit in the heating / reheating-side combustion system 40 in which the heating operation is performed according to the degree of the possibility of freezing based on the data table shown in FIG. The maximum rotational speed of the blower fan 70 that supplies combustion air to 43 is reduced by a predetermined reduction amount. Although not shown, the hot water supply operation is performed in the hot water supply side combustion system 30, but the same data is also applied to the case where neither the heating operation nor the additional operation is performed in the heating side / additional combustion system 40. A table is provided.

  Referring to FIG. 3, the determination of the possibility and the degree of freezing in the heat source device 1 of the present embodiment and the combustion control when there is a possibility of freezing will be schematically described. A plurality of (in this case, three stages of first to third regions) freezing risk temperature regions are set for the temperature Th, and a plurality (here, the first to third regions) for the hot water temperatures Ta and Tb. A three-step reference temperature region is set. Then, the maximum rotational speed of the blower fan 70 is decreased by a predetermined reduction amount set according to the temperature range to which the outside air temperature Th and the hot water temperatures Ta and Tb belong. For example, when the outside air temperature Th is lower than −10 ° C. but is −15 ° C. or higher, and the hot water temperatures Ta and Tb are lower than 10 ° C., but 8 ° C. or higher, the normal combustion control is set. The maximum rotational speed of the blower fan 70 is reduced by 10%. Therefore, as shown in FIG. 2, the target rotational speed of the blower fan 70 is set to the maximum rotational speed in the normal combustion control (here, the first-stage maximum rotational speed R1q) (about 330 Hz) at the time of freezing. Combustion control is performed within the combustion amount range of each capability stage corresponding to the maximum rotational speed Rsq (10% ↓) (about 300 Hz) or less. In addition, when a plurality of capacity steps are provided as in the heating-side burner unit 43 of the present embodiment, and the maximum number of rotations varies according to the number of capacity steps, the maximum number of freezing is reduced by a predetermined reduction amount. The number of revolutions may be higher than the maximum number of revolutions of different capacity stages (for example, the maximum number of revolutions Rsq (10% ↓) during freezing and the second stage side maximum number of revolutions R2q). Therefore, in this case, the maximum number of rotations of each capability stage in the normal combustion control is maintained.

  Similarly, when the outside air temperature Th is lower than −15 ° C. but is −20 ° C. or higher, and the hot water temperatures Ta and Tb are lower than 8 ° C., but 6 ° C. or higher, the normal combustion control is set. The maximum rotational speed of the blower fan 70 is reduced by 20%. Therefore, as shown in FIG. 2, the target rotational speed of the blower fan 70 is reduced by 20% from the maximum rotational speed (about 330 Hz) in normal combustion control, and the maximum rotational speed Rsq during freezing Rsq (20% ↓) (about 270 Hz). Combustion control is performed with the following restrictions. As described above, when there is a possibility of freezing, the target rotation speed of the blower fan 70 is decreased by a predetermined reduction amount from the maximum rotation speed in the normal combustion control, and the first stage side combustion amount range G1 and the second rotation amount range. By limiting to the maximum freezing rotation speed Rsq that is the range of the overlap allowance with the stage side combustion amount range G2, when the heating-side burner unit 43 is burned in the first stage side combustion amount range G1, Even if the combustion amount in the second stage side combustion amount range G2 within the range is required, the number of capacity stages is maintained. Therefore, freezing of the hot water supply side combustion system 30 in which the combustion operation is not performed can be prevented while suppressing hunting.

  Furthermore, when the outside air temperature Th is lower than −20 ° C., it is −25 ° C. or higher, and the hot water temperatures Ta and Tb are lower than 6 ° C., but when the temperature is 4 ° C. or higher, it is set in the normal combustion control. The maximum rotational speed of the blower fan 70 is reduced by 30%. At this time, as shown in FIG. 2, when the combustion operation of the heating-side burner unit 43 is performed in the first combustion amount range G1 on the low combustion amount side, the maximum rotational speed (about 330 Hz) in the normal combustion control. Is reduced by 30%, it becomes lower than the minimum rotational speed (about 260 Hz) in the range of the overlap margin with the adjacent upper combustion amount range of the high combustion amount side. Therefore, a fixed maximum freezing speed Rsq (30% ↓) (about 230 Hz) below the range of the overlap allowance is set, and the target rotational speed of the blower fan 70 is set below the fixed maximum freezing speed Rsq. Limited combustion control is performed. Thus, when the heating-side burner unit 43 is burned in the first stage combustion amount range G1, the fixed maximum rotation during freezing is required until the minimum combustion amount G2p of the second stage combustion amount range G2 is required. The combustion fan 70 is rotated by a number Rsq, and the capacity stage number in the first stage side combustion amount range G1 is maintained. On the other hand, when the heating-side burner unit 43 is burned in the second stage combustion amount range G2, a combustion amount corresponding to the fixed maximum rotation speed Rsq during freezing in the first stage combustion amount range G1 is required. Until this time, combustion is performed with the minimum combustion amount G2p in the second stage side combustion amount range G2, and the capacity stage number in the second stage side combustion amount range G2 is maintained. Therefore, switching of the number of capacity stages to the high combustion amount side and the low combustion amount side can be reduced, and freezing of the hot water supply side combustion system 30 in which the combustion operation is not performed can be reliably prevented while suppressing hunting as much as possible. .

  In addition, as understood from the above, in the present embodiment, the first reference temperature that sets the maximum number of revolutions during freezing within the range of overlap with the upper combustion range is set to 10 ° C., The second reference temperature for fixing the maximum number of revolutions during freezing below the range of overlap with the upper combustion amount range is set to 6 ° C. Including these, the freezing dangerous temperature, the reference temperature, and their temperature range Is appropriately set according to the structure of the combustion systems 30 and 40 and the capability of the blower fan 70. In the present embodiment, both the outside air temperature and the hot water temperature are set only up to the third region, but a lower temperature region may be set according to the installation environment of the heat source device 1. In this case, the target rotation speed of the blower fan 70 is limited to a fixed maximum rotation speed during freezing.

  Thus, according to the heat source device 1 of the present embodiment, for example, when the heating operation is performed in the heating / reheating side combustion system 40 and the hot water supply operation is not performed in the hot water supply side combustion system 30, The temperature Ta and Tb of the hot water in the fluid flow path of the hot water supply side combustion system 30 not being subjected to the combustion operation in which freezing is actually likely to occur are not only the case where the temperature Th becomes lower than the predetermined freezing danger temperature. Since it is also determined whether or not it becomes lower, it is possible to determine the possibility of freezing of the fluid flow path of the hot water supply side combustion system 30 where the combustion operation is not performed more accurately. Moreover, since it is determined whether or not the outside air temperature Th and the hot water temperatures Ta and Tb in the fluid flow channel are both within the range of the freezing danger temperature region and the reference temperature region, the possibility of freezing is determined. The degree can also be judged.

  In the normal combustion control of the heat source device 1, the blower fan 70 is rotated at a predetermined maximum number of rotations or less according to the required combustion amount required for the burner units 33 and 43 in the combustion systems 30 and 40. For example, when the heating operation is performed in the heating / heating-side combustion system 40 and the hot water supply operation is not performed in the hot water supply side combustion system 30, freezing can be performed based on the outside temperature Th and the hot water temperatures Ta and Tb. When the target rotational speed of the blower fan 70 for supplying combustion air to the heating / reheating-side combustion system 40 in which the combustion operation is performed is reduced below the maximum rotational speed Limited to less than maximum speed. Therefore, the inflow of air to the hot water supply side combustion system 30 where the combustion operation by rotating the blower fan 70 is not performed is suppressed, and the possibility of freezing of the fluid flow path of the hot water supply side combustion system 30 can be reduced.

  Further, in the present embodiment, when the possibility of freezing is low, the target rotation speed of the blower fan 70 is overlapped with the upper combustion amount range that is lower than the maximum rotation speed set in the normal combustion control. Combustion control is performed by limiting to the maximum rotation speed during freezing within the range of allowance. Therefore, for example, when the heating operation is performed in the heating / heating-side combustion system 40 and the hot water supply operation is not performed in the hot water supply side combustion system 30, the heating side burner unit 43 is effectively prevented from hunting. Freezing of the fluid flow path of the hot water supply side combustion system 30 can be avoided.

  Further, in the present embodiment, when the possibility of freezing is high, the target rotational speed of the blower fan 70 is overlapped with the upper stage combustion amount range that is lower than the maximum rotational speed set in the normal combustion control. Combustion control is performed by limiting the rotation speed to a fixed maximum freezing speed or less that is less than the allowable range. Therefore, for example, when the heating / burning side combustion system 40 performs the heating operation and the hot water supply side combustion system 30 does not perform the hot water supply operation, the heating side burner unit 43 is burned in the lower combustion amount range. When the heating stage burner unit 43 is burned in the upper combustion quantity range until the minimum combustion quantity in the upper combustion quantity range is required, the maximum rotation during freezing when the lower combustion quantity range is fixed. Until the combustion amount corresponding to the number is required, the combustion is performed with the minimum combustion amount in the upper combustion amount range, and the capacity stage number is maintained. Therefore, freezing of the fluid flow path of the hot water supply side combustion system 30 can be effectively avoided while suppressing hunting of the heating side burner unit 43 as much as possible.

  Next, the control operation at the time of heating operation in the heat source device 1 of the present embodiment will be described with reference to the flowchart of FIG. In the following description, a control operation when the heating / heating side combustion system 40 performs the heating operation and the hot water supply side combustion system 30 does not perform the hot water supply operation will be described as an example. The control operation when the hot water supply operation is performed at 30 and neither the heating operation nor the additional operation is performed at the heating / reheating side combustion system 40 is performed by the heat exchange temperature sensor 101 in the determination of the possibility of freezing. It is the same except that the temperature of hot water detected by the heating high temperature sensor 213 and the heating low temperature sensor 215 is used instead of the detected hot water temperature Ta and the hot water temperature Tb detected by the tapping temperature sensor 103. . Further, when the reheating operation is performed, it is the same as the heating operation except that the bath pump 224 is operated and hot water is circulated in the bath going-out path 251 and the bath return path 252.

  For example, when the user turns on the heating operation switch of the remote controller 301, the operation of the blower fan 70 and the heating pump is started, and the combustion operation of the heating-side burner unit 43 is started. When the heating operation is started, it is first determined whether or not the hot water supply operation is performed (step S1). When the hot water supply operation is performed, the possibility of freezing of the fluid flow path in the hot water supply side combustion system 30 is low. Therefore, the blower fan 70 is set to a predetermined minimum rotation speed according to the required combustion amount according to the set heating operation mode. The normal combustion control for rotating the engine within the range of the maximum rotation speed is executed (step S7).

  When the hot water supply operation is not performed, it is further determined whether or not the outside air temperature Th detected by the outside air temperature sensor 11 is equal to or lower than a predetermined freezing prevention operation start temperature (for example, 3 ° C.) (step S2). If the outside air temperature Th is not equal to or lower than the freezing prevention operation start temperature, similarly, the possibility of freezing the fluid flow path in the hot water supply side combustion system 30 is low, so normal combustion control is executed (step S7).

  When the outside temperature Th becomes equal to or lower than the freeze prevention operation start temperature, the freeze prevention heaters 401 to 406 provided in the fluid flow path of the hot water supply side combustion system 30 are provided with a predetermined time interval (for example, on / 5 minutes-off / 25). The antifreezing operation for heating the fluid flow path is started (step S3). Although not shown, the freeze prevention operation is terminated when the time interval of the energization time is changed according to the outside air temperature Th and the hot water temperatures Ta and Tb and the outside air temperature Th becomes higher than the freeze prevention operation start temperature.

  Next, the outside air temperature Th becomes less than a predetermined freezing risk temperature (for example, −10 ° C.), and at least one of the hot water temperature Ta detected by the heat exchange temperature sensor 101 and the hot water temperature Tb detected by the tapping temperature sensor 103. When one of them is lower than a predetermined reference temperature (for example, 10 ° C.), the reduction amount set according to the outside air temperature Th and the hot water temperatures Ta and Tb is determined based on the data table of FIG. Based on the largest reduction amount in which the rotational speed becomes lower among the reduction amounts, the target rotational speed of the blower fan 70 is limited to be equal to or less than the maximum rotational speed during freezing (steps S4 to S6).

  Thus, when the reduction amount of the maximum rotation speed of the blower fan 70 based on the outside air temperature Th and the reduction amount of the maximum rotation speed of the blower fan 70 based on the hot water temperatures Ta and Tb are different, a larger reduction amount is used. By limiting to the maximum number of revolutions during freezing, freezing of the fluid flow path in the hot water supply side combustion system 30 in which the combustion operation is not performed can be avoided more reliably.

  As described above, when the target rotation speed of the blower fan 70 is limited to the fixed maximum rotation speed during freezing that is equal to or less than the range of overlap with the upper combustion amount range, the heating-side burner unit 43 is If combustion is in the lower combustion range, combustion is continued in the lower combustion range until the minimum combustion amount in the upper combustion range is required, and the heating burner unit 43 is combusted in the upper combustion range. If so, the combustion control is performed to continue the combustion with the minimum combustion amount in the upper combustion amount range until the combustion amount corresponding to the maximum freezing rotation speed in which the lower combustion amount range is fixed is required.

  As described above in detail, according to the present embodiment, in the heat source device having a plurality of combustion systems, there are a combustion system in which the combustion operation is performed and a combustion system in which the combustion operation is not performed. In addition, it is possible to efficiently prevent freezing of the fluid flow path in the combustion system in which the combustion operation is not performed.

(Other embodiments)
(1) In the above embodiment, the possibility of freezing is determined based not only on the fluid temperature of the fluid flow path but also on the outside air temperature, but the possibility of freezing is determined based only on the fluid temperature. Also good.
(2) In the above embodiment, in determining the possibility of freezing, the freezing danger temperature and the reference temperature are divided into a plurality of freezing danger temperature areas and a reference temperature area. The critical freezing temperature and the reference temperature may be used.
(3) In the above-described embodiment, the heat source device in which a plurality of combustion systems are accommodated in one can body has been described. However, as described above, a plurality of can bodies in which each burner unit and heat exchanger are accommodated. The present invention can also be applied to a combined heat source device. In the above embodiment, the forced supply / exhaust type heat source apparatus has been described in which a plurality of combustion systems have a common supply / exhaust path. However, the present invention is also applied to a forced exhaust type heat source apparatus in which only the exhaust path is shared. Can be applied. Furthermore, in the above-described embodiment, the hot water supply device with a heating / reheating function has been described as an example, but a heat source device having a plurality of combustion systems, such as a hot water supply device with a heating function or a hot water supply device with a reheating function, is described. The present invention can be applied.
(4) In the above embodiment, hot water is used as the fluid flowing through the fluid flow path of the heating / reheating side combustion system, but antifreeze may be used.

1 Heat source device 11 Outside air temperature sensor (outside air temperature detector)
DESCRIPTION OF SYMBOLS 30 Hot water supply side combustion system 40 Heating and reheating side combustion system 33 Hot water supply side burner unit 31 Hot water supply side 1st heat exchanger 32 Hot water supply side 2nd heat exchanger 41 Heating side 1st heat exchanger 42 Heating side 2nd heat exchanger 43 Heating side burner unit 70 Blower fan 101 Heat exchanger temperature sensor 103 Hot water temperature sensor 213 Heating high temperature sensor 215 Heating low temperature sensor C1 Control circuit

Claims (4)

A burner unit having a burner, a heat exchanger that heat-exchanges and heats a fluid that flows through a fluid flow path by combustion exhaust generated by the burner unit, and at least one fluid temperature detection unit that detects the temperature of the fluid flowing in the fluid flow path A plurality of combustion systems each having
A blower fan that supplies combustion air to one or more combustion system burner units;
A control device for performing normal combustion control for controlling the target rotational speed of the blower fan at a predetermined maximum rotational speed or less in accordance with the required combustion amount required for the burner unit of the combustion system performing the combustion operation,
This is a heat source device in which air flows into other combustion systems that are not operating by rotating the blower fan to supply combustion air to the burner unit of the combustion system that is performing the combustion operation. And
When the combustion operation is performed in at least one combustion system and the combustion operation is not performed in the other combustion system, the control device is detected by the fluid temperature detection unit of the other combustion system in which the combustion operation is not performed. When the fluid temperature is lower than the predetermined reference temperature, the target rotational speed of the blower fan that supplies combustion air to the combustion system in which the combustion operation is performed is lower than the maximum rotational speed when the target rotational speed is lower than the maximum rotational speed. Heat source device limited to. The heat source device according to claim 1, further comprising:
It has an outside air temperature detector that detects the outside air temperature,
The control device is configured such that the outside air temperature detected by the outside air temperature detecting unit is lower than a predetermined freezing danger temperature and the fluid temperature detected by the fluid temperature detecting unit of another combustion system in which the combustion operation is not performed is the predetermined temperature. A heat source device that limits a target rotational speed of a blower fan that supplies combustion air to a combustion system in which a combustion operation is performed when the temperature is lower than a reference temperature to be equal to or lower than a maximum rotational speed during freezing that is lower than the maximum rotational speed. The heat source device according to claim 1 or 2,
The burner unit of at least one combustion system among the plurality of combustion systems has a plurality of capacity stages having different combustion amount ranges,
When the combustion operation is performed in a combustion system including a burner unit having a plurality of capacity stages, the control device has a lower combustion amount range on the low combustion amount side and an upper combustion amount range on the high combustion amount side adjacent thereto. In between, the normal combustion control is performed to switch and control the number of capacity stages using the overlap margin provided so that the maximum combustion amount in the lower combustion amount range is larger than the minimum combustion amount in the upper combustion amount range. ,
Fluid temperature detection in other combustion systems where combustion operation is performed when a combustion system is equipped with a burner unit having a plurality of capacity stages and combustion operation is not performed in another combustion system When the fluid temperature detected by the unit becomes lower than the predetermined first reference temperature, the target rotational speed of the blower fan that supplies the combustion air to the burner unit of the combustion system in which the combustion operation is performed is increased from the maximum rotational speed. A heat source device that limits a predetermined reduction amount that falls within a range of overlap with the side combustion amount range, to a lower value than the reduced maximum rotation speed during freezing. The heat source device according to claim 1 or 2,
The burner unit of at least one combustion system among the plurality of combustion systems has a plurality of capacity stages having different combustion amount ranges,
When the combustion operation is performed in a combustion system including a burner unit having a plurality of capacity stages, the control device has a lower combustion amount range on the low combustion amount side and an upper combustion amount range on the high combustion amount side adjacent thereto. In between, the normal combustion control is performed to switch and control the number of capacity stages using the overlap margin provided so that the maximum combustion amount in the lower combustion amount range is larger than the minimum combustion amount in the upper combustion amount range. ,
Fluid temperature detection in other combustion systems where combustion operation is performed when a combustion system is equipped with a burner unit having a plurality of capacity stages and combustion operation is not performed in another combustion system When the fluid temperature detected by the unit becomes lower than the predetermined second reference temperature, the target rotational speed of the blower fan that supplies the combustion air to the burner unit of the combustion system in which the combustion operation is performed is set to be higher than the maximum rotational speed. A heat source device that restricts to a fixed maximum freezing speed during freezing that is less than the range of the overlap allowance with the lower upper combustion amount range.

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