JP6645090B2 - Consolidated hot water supply system - Google Patents

Description

  The present invention relates to a coupled hot water supply system for controlling the number of two or more water heaters interposed in parallel between a water inlet path and a hot water path, and more particularly, to the occurrence of hot water supply interruption due to a blockage of a water supply / exhaust passage. The present invention relates to a technology capable of continuously supplying hot water while avoiding air supply and exhaust obstruction.

In Patent Literature 1 below, one of two or more water heaters is selected and set as a main water heater to start a hot water supply operation first when a hot water supply request is issued, and a cumulative operation time of the main water heater is predetermined. When the time is reached, the data on the thermal efficiency of each water heater is collected for a connected hot water supply system that performs rotation control in which the role of the main water heater is changed to another water heater and replaced. It is described that a water heater is set as a main water heater in preference to a low water heater.
Further, in Patent Document 2 below, when a component for hot water operation is provided, if any of the hot water heaters detects an abnormality in the component for hot water operation provided in each water heater, It is described that a water heater in which the occurrence of the abnormality is detected is excluded from the allocation setting target as the main water heater.

JP 2008-298365 Patent No. 5589610

  By the way, in each of the water heaters constituting the combined hot water supply system, the use of hot water supply, that is, the water supplied to the heat exchanger is combined with the combustion heat of the combustion burner which is burned by receiving the supply of combustion air by the blower fan. If the hot water supply is continued by heating by heat exchange and supplying hot water after heating, the resistance of the supply / exhaust flow path that flows to the exhaust section as the combustion air supplied by the blower fan becomes combustion gas or combustion exhaust It tends to increase. This is due to deposits adhering to the gaps of the heat exchanger and blockage of the supply / exhaust flow path due to the inflow of wind from the exhaust stack, etc., in order to maintain a predetermined air-fuel ratio. Correction control is performed to sequentially increase and correct the target rotation speed of the blower fan in accordance with the progress of the degree of blockage. When the increase correction amount reaches a predetermined upper limit, control is performed to forcibly stop the hot water supply operation.

  However, if the hot water supply operation is forcibly stopped due to the blockage particularly in the water heater that is first burned and the hot water supply operation is performed if there is a hot water supply request allocated to the main water heater, the replacement is performed because the main water heater is used. Therefore, the whole connected hot water supply system is stopped. In such a case, the hot water supply that has been continued until then is suddenly stopped, and there is a possibility that hot water may run out in the hot water storage tank or the like at the hot water supply destination, which may cause inconvenience to the user.

  The present invention has been made in view of such circumstances, and an object of the present invention is to interrupt the use of hot water supply even if the supply / exhaust flow path of the water heater constituting the combined hot water supply system tends to be blocked. It is an object of the present invention to provide a connected hot water supply system capable of continuing to use hot water by the connected hot water supply system for a longer period without inducing.

  In order to achieve the above object, a plurality of water heaters interposed in parallel between a water inlet path and a hot water path, and the plurality of water heaters are connected to the plurality of water heaters for communication. A plurality of water heaters, each of which controls the number of water heaters to be operated, and each of the plurality of water heaters determines a degree of blockage of the supply / exhaust flow path, and the degree of blockage increases to a predetermined first determination level. Then, a safety function for forcibly stopping the hot water supply operation is provided, and the number control unit controls the plurality of water heaters to perform a hot water supply operation first when hot water supply is used, and a second and subsequent hot water supply operations. A combined hot water supply system configured to assign and set one of the roles of a sub-water heater and to rotate the role of the main water heater alternately with any of the sub-water heaters. The in the subject provides the following technical means.

That is, when the degree of blockage of the water heater assigned and set as the main water heater increases to the second determination level lower than the first determination level as the number control unit, the allocation setting as the main water heater is changed. release and by assignment set as a sub-water heater, and one you prohibit be allocated set as the main water heater by excluding from the allocation set as the subsequent main water heater, assignment as the main water heater If the degree of blockage of the water heater whose setting is prohibited decreases to a lower level range than the second determination level with the passage of time, the prohibition of the allocation setting is released and the allocation setting as the main water heater is permitted. and configuration to (claim 1).

In the case of the present invention, it is possible to avoid running out of hot water as much as possible in the use of hot water supply using the connected hot water supply system, and it is possible to continuously use the connected hot water supply system for a long time. This makes it possible to improve the comfort of the user when using hot water. In other words, the main hot water heater plays the role of operating the hot water supply operation first when the hot water supply is used, and only one hot water supply operation is performed depending on the hot water supply request. In some cases, the degree of blockage reaches the first determination level earlier than in the sub water heater. If the forced operation is stopped while only one hot water supply system is being operated, running out of hot water, that is, interruption of the use of hot water supply, will be inevitable, resulting in inconvenience to the user. On the other hand, in the present invention, before the degree of blockage reaches the first determination level, the allocation setting of the main water heater is canceled when the second determination level in the lower level range is reached. It is possible to avoid unexpected running out of hot water due to the forced operation stop processing, and it is also possible to avoid the possibility of inconvenience to the user. In addition, since the main water heater is released as a sub-water heater even after the setting of the main water heater is released, the hot water supply for a longer time is maintained while maintaining the original hot water supply capacity of the combined hot water supply system. it is possible to continue to use and that Do not. In addition, as the number control unit, if the degree of blockage of the water heater for which the allocation setting as the main water heater is prohibited is reduced to a lower level range than the second determination level with time, the prohibition of the allocation setting is released. Even if the allocation setting as the main water heater is canceled once and the allocation setting as the main water heater is prohibited, the degree of blockage is improved. Thereby, it can be returned as the main water heater. As a result, continuous use of hot water by the combined hot water supply system can be ensured for a longer period of time due to an increase in the number of objects to be allocated as main water heaters.

  In the combined hot water supply system of the present invention, as the number control unit, the allocation setting as the main water heater is released, while the degree of blockage from among the other water heaters allocated and set as the sub water heater is lower than the second determination level. A configuration is possible in which a water heater in the low level range is assigned and set as a new main water heater. By doing so, the hot water heater assigned and set as the main hot water heater can be continuously used as the main hot water heater for a longer time, so that it is possible to contribute to the realization of continuous hot water use by the combined hot water supply system. Become.

Further, in the coupled hot water supply system of the present invention, each of the plurality of water heaters includes a blower fan for supplying combustion air, and a fan control unit for controlling an operation control amount of the blower fan, wherein the fan The control unit may be configured to increase and correct the target rotation speed of the blower fan by a predetermined ratio each time it is determined that a predetermined blockage state has occurred, and that the first determination level and the second determination level are set to the target rotation speed. in response to the cumulative ratio after correction of increasing the rotational speed can be as specified (claim 3). By doing so, it is possible to provide a connected hot water supply system that further embodies the present invention, and it is possible to more specifically obtain the effects of the present invention.

As described above, according to the coupled hot water supply system of the present invention, in hot water supply using the coupled hot water supply system, even if the supply / exhaust flow path of the water heater falls into a closed state, occurrence of running out of the hot water can be minimized. The hot water supply system can be continuously used for a long period of time. This makes it possible to improve the user's comfort in using hot water. In other words, the main hot water supply unit plays a role of operating the hot water supply operation first when the hot water supply is used, and the hot water supply operation is performed only by one unit depending on the hot water supply request, so that the progress of the closed state of the supply / exhaust flow path and the In some cases, the degree of blockage reaches the first determination level earlier than in the sub water heater. If the forced operation is stopped when only one hot water supply system is being operated, running out of hot water, that is, interruption of the use of hot water supply, is inevitable, resulting in inconvenience to the user. On the other hand, in the present invention, before the degree of blockage reaches the first determination level, the allocation setting of the main water heater is canceled when the second determination level in the lower level range is reached. It is possible to avoid unexpected running out of hot water due to the forced operation stop processing, and it is possible to avoid the possibility of inconvenience to the user. In addition, since the main water heater is released as a sub-water heater even after the allocation setting of the main water heater is released, the hot water supply is continued for a longer time while maintaining the original hot water supply capacity of the combined hot water supply system. ing to be able to continue to use. In addition, as the number control unit, if the degree of blockage of the water heater for which the allocation setting as the main water heater is prohibited is reduced to a lower level range than the second determination level with the elapse of time, the prohibition of the allocation setting is released. Even if the allocation setting as the main water heater is canceled once and the allocation setting as the main water heater is prohibited, the degree of blockage is improved. Thus, it can be returned as the main water heater. As a result, the number of objects to be allocated as the main hot water heater can be increased, and continuous use of hot water by the combined hot water supply system can be ensured for a longer period.

  In particular, according to the coupled hot water supply system of the second aspect, as the number control unit, the allocation setting as the main water heater is released, while the degree of blockage from among the other water heaters allocated and set as the sub-water heater is determined. 2. By assigning and setting a water heater in a lower level range than the determination level as a new main water heater, the water heater assigned and set as the main water heater can be continuously used as the main water heater for a longer time. This can contribute to the realization of continuous use of hot water supply by the combined hot water supply system.

Furthermore, according to the coupled hot water supply system of claim 3 , each of the plurality of water heaters includes a blower fan for supplying combustion air, and a fan control unit for controlling an operation control amount of the blower fan. The fan control unit may be configured to increase and correct the target rotation speed of the blower fan by a predetermined ratio each time it is determined that a predetermined blockage state has occurred, and a first determination level and a second determination level Is specified corresponding to the cumulative ratio of the target rotation speed after the increase correction, it is possible to provide a connected hot water supply system that further embodies the present invention, and to further reduce the effects of the present invention. Will be able to get to.

1 is an overall schematic diagram illustrating an example of a connected hot water supply system including a control device according to an embodiment of the present invention. It is a schematic diagram which shows the example of a structure of each water heater of FIG. FIG. 2 is a block diagram illustrating a configuration related to operation control of the coupled hot water supply system of FIG. 1. 6 is a time chart showing a correction process executed as the air supply / exhaust passage closes in a blower fan of each water heater and a process when the water heater is a main water heater. It is a flowchart which shows the example of the monitoring control with respect to the main water heater of the connection hot-water supply system of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram showing a connected hot water supply system according to an embodiment of the present invention. In this connection hot water supply system, two or more predetermined number of water heaters 3, 3,... Having the same configuration controlled by the system controller 2 are connected in parallel between the water supply path 5 and the hot water supply path 6. In the example of the figure, a case where the connected hot water supply system is constituted by six water heaters 3, 3,... Is illustrated, and reference numerals 3a, 3b,.

  Each water heater 3 has its water inlet 32 connected to a water inlet path 5 for receiving water from a water pipe or the like, while its water outlet 33 has a water outlet path 6 having a hot water storage tank or a hot water tap (not shown) as a downstream end. Are connected in parallel. In the combined hot water supply system, each hot water heater 3 performs hot water supply operation control mainly based on operation control of a combustion system by an individual controller 31 built in each hot water heater 3, and each individual controller 31 communicates with the system controller 2 via a communication connection line. The communication control unit 71 is individually connected so as to be capable of two-way communication, and receives from the system controller 2 information relating to the setting of the role mainly assigned in the number control and the set tapping temperature set in the remote controller 20.

  By connecting the system controller 2 and the individual controllers 31, 31,... Of each water heater 3 by the communication connection line 71, the system controller 2 connects the water heaters 3, 3,. Recognize the number (six in the example in the figure) and the respective water heaters 3a, 3b,... And store them in, for example, a nonvolatile memory (see the setting storage unit 213 in FIG. 3). Each of the system controller 2 and the individual controllers 31, 31,... Includes an MPU, a memory (EEPROM), an interface, and the like, and stores various control programs. A power supply current from a power supply line 72 for supplying power to the power supply is received via the power supply board.

  An example of each water heater 3 constituting the above-described linked hot water supply system will be described. FIG. 2 shows a gas water heater for burning gas as fuel as an example of the water heater 3. In addition, the water heater 3 illustrated in FIG. 2 heats incoming water from the water inlet 32 by combustion heat, and discharges heated water from the outlet 33, and is a water heater having such a function. If so, the combined hot water supply system 2 of the present invention can be configured using another type of water heater that does not use the heat exchanger 34 described later, or an oil water heater that burns petroleum (eg, kerosene) as fuel. .

  The water heater 3 is provided with a heat exchanger 34, a water inlet 35 for allowing water from the water inlet path 5 to enter the heat exchanger 34 from the water inlet 32, and a hot water heated by the heat exchanger 34. A tapping path 36 for tapping water from the gate 33 to the tapping path 6, a bypass path 37 for mixing water with tapping water from the heat exchanger 34, and the heat exchanger 34 is heated by combustion heat. And a combustion burner 38 as a combustion section. The heat exchanger 34 and the combustion burner 38 are built in a can 39, and a blower fan 40 is attached to the can 39. Then, the combustion burner 38 is burned by receiving the combustion air supplied from the blower fan 40, and heat-exchanges the incoming water in the heat exchanger 34.

  The water inlet passage 35 is provided with an incoming water flow rate sensor 41 for detecting the incoming water flow rate and an incoming water temperature sensor 42 for detecting the incoming water temperature. The tapping path 36 is provided with a can body temperature sensor 43 for detecting the can body temperature immediately after being heated by the heat exchanger 34 at a position upstream of the merging position with the downstream end of the bypass path 37. A flow control valve 44 for adjusting the flow rate of tap water at a position downstream of the junction position and a tap temperature sensor 45 for detecting the actual tap temperature are provided. The bypass passage 37 is provided with a bypass flow control valve 46 for mixing water from the water inlet passage 35 with the hot water from the hot water passage 36 at a predetermined mixing ratio. At least the flow control valve 44 among the flow control valve 44 and the bypass flow control valve 46 has a fully-closed switching function capable of closing to a fully-closed state where the valve opening amount is zero based on a control signal from the system controller 2. In addition, when the state is switched to the fully closed state, water from the water inlet path 5 is shut off. Thus, switching between hot water use and non-use by controlling the number of hot water supply units is performed by setting the flow control valve 44 to the normal operation state of the flow rate adjusting function or to the fully closed switching state by the fully closed switching function. It is not necessary to separately provide a dedicated electromagnetic opening / closing valve on the path or the like.

  The hot water supply operation control by the individual controller 31 provided in each water heater 3 includes a request for hot water supply (for example, opening of a hot water tap), a flow rate of water from the water supply path 5 to the water supply path 35 is equal to or more than the minimum operation flow rate (MOQ). Is detected by the incoming water flow sensor 41, the fuel gas supply system (not shown) to the combustion burner 38, the combustion system 47 including the ignition mechanism (only shown in FIG. 3), the blower fan 40, etc. By controlling the operation, the combustion burner 38 is burned with a predetermined amount of combustion so that the temperature of the hot water discharged into the hot water path 6 becomes the set hot water temperature. That is, based on the predetermined air-fuel ratio and the required combustion amount (request number), the corresponding control values of the fuel gas supply amount and the air supply amount are calculated, and the calculated fuel gas supply amount is calculated. While the operation of the fuel gas supply system is controlled, the operation of the blower fan 40 is controlled so as to achieve the determined air supply amount.

  Particularly, the operation control and the correction control of the blower fan 40 are executed by a fan controller 311 (see FIG. 3) provided in each individual controller 31. That is, the basic operation control of the blower fan 40 is to control the rotation speed of the fan motor of the blower fan 40 so as to achieve a predetermined air supply amount. The control is performed by controlling the fan current value so as to attain a predetermined target rotation speed based on a control table predetermined for the rotation speed and the fan current value. When the combustion air is supplied from the blower fan 40 and the combustion burner 38 is burned, the water in the heat exchanger 34 is heated by heat exchange with the combustion heat and passes through the heat exchanger 34. The combusted exhaust gas is released from the exhaust stack to the outside. Such a flow of the combustion exhaust gas is generated based on the supply pressure of the air from the uppermost blower fan 40, and the flow of the combustion gas and the combustion exhaust gas of the heat exchanger 34 in the can body 39. The flow path resistance increases due to the accumulation of deposits in the gap or the flow of air from the exhaust pipe, and even if the fan speed is maintained at the same speed due to the increase in the flow path resistance. The value tends to decrease. For this reason, by observing the relationship between the rotation speed detection value of the blower fan 40 and the fan current value, it is possible to monitor the increase in the flow path resistance (blockage state) and correct the basic operation control amount of the blower fan 40. The correction control to be added is executed.

  In the correction control by the fan control unit 311, basically, the target rotation speed is sequentially increased and corrected by a predetermined ratio (for example, by 1%) in accordance with the increase of the flow path resistance, and the correction amount becomes a predetermined upper limit. When the temperature reaches the value, the hot water supply operation is stopped for a prescribed time and the subsequent hot water supply operation is prohibited. A specific example will be described with reference to FIG. 4. First, when a combustion operation of the combustion burner 38 is performed, a reading value of a fan current value of the blower fan 40 is set to a fan current value corresponding to a target rotation speed by basic operation control at that time. If the target flow rate decreases by more than a predetermined amount, it is determined that the flow path resistance is increasing and changing, that is, a blockage situation is occurring, and the target rotational speed is corrected to increase by a predetermined ratio (1% in the illustrated example). If the fan current value decreases by a predetermined amount despite the increase correction, an additional 1% increase correction is added to the target rotation speed. As a result, a cumulative increase amount of 2% is obtained. In this way, each time the fan current value decreases, additional correction is performed by 1%. When the cumulative correction amount reaches the upper limit value (first determination value; for example, 10%), the hot water supply operation control is forcibly terminated and stopped. The subsequent operation is prohibited, and the individual controller 31 outputs information to that effect to the system controller 2. Then, when the system controller 2 receives from the individual controller 31 the information indicating that the hot water supply operation control is forcibly terminated and stopped and the subsequent operation is prohibited, the corresponding water heater 3 is set as the main water heater and the sub water heater. After that, it is excluded from the assignment setting target, and this is stored in the setting storage unit 213. The hot water supply operation control unit (not shown) included in the individual controller 31 is responsible for the above-described processing of forcibly stopping the hot water supply operation control when the accumulated correction amount reaches the first determination value. Alternatively, this processing part can be assigned to the number controller 21 of the system controller 2 instead.

  In the course of the basic correction control described above, if the cumulative correction amount reaches a predetermined second determination value (for example, a 5% cumulative correction amount), the individual controller of the water heater 3 in which the hot water supply operation control is being performed. 31 outputs a signal to that effect to the monitoring controller 212 of the system controller 2. When the water heater 3 is operating as a sub-water heater, the hot water supply operation control and the continuation of the control by the fan control unit 311 are not changed to the upper limit value (first determination value; for example, a 10% cumulative correction amount). ) Is allowed. In the correction control in this case, assuming that the initial basic control amount in normal operation is 100%, the control amount is increased by 101% to 110% (cumulative correction amount 10%), for example, by 1% by the correction control. become. The information output to the system controller 2 that the cumulative correction amount has reached the second determination value is limited to a case where the water heater 3 in which the hot water supply operation control is being performed is operating as the main water heater, and When operating as a container, the above information output can be omitted. In the above example, the magnitude of the cumulative correction amount indicates the degree of occlusion, and the first determination value indicates the first determination level as the degree of occlusion in claims, and similarly, the second determination value indicates the second determination level. Become.

  In addition, each individual controller 31 receives a control signal of combustion permission (use hot water) or prohibits combustion (use of no hot water) from the number control unit 21 by communication with the system controller 2 and executes corresponding control. It has become. That is, when the combustion prohibition command is received, the flow control valve 44 is switched to the fully closed state based on the fully closed switching command received together with the combustion prohibition command, and even if water flows into the water inlet passage 5, the water does not flow into the water inlet passage 35. On the other hand, when a combustion permission command is received, the flow control valve 44 is switched to open based on the open switching command received together with the combustion permission command, so that water can enter the water path 35 from the water path 5. ing.

  The system controller 2 includes a number control unit 21 as shown in FIG. 3, and the number control unit 21 includes a basic control unit 211, a monitoring control unit 212, and a setting storage unit 213. Such a system controller 2 can be installed separately from each water heater 3, or can be installed together with the individual controller 31 in any one of the water heaters 3. The number control by the basic control unit 211 of the number control unit 21 is configured as follows. That is, the system controller 2 selects any one of the hot water heaters (for example, 3a) from all the hot water heaters 3a, 3b,... Constituting the combined hot water supply system, and burns this one hot water heater 3a first. Are assigned to the main water heaters to be added and the sub water heaters that additionally burn the other water heaters 3b, 3c, 3d,... To satisfy the hot water supply request, and the setting information is stored in the setting storage unit 213. . During the hot water supply standby state, the combustion permission command is transmitted only to the main water heater 3a, and the combustion prohibition command is transmitted to the other sub water heaters 3b, 3c, 3d,. That is, at the time of standby for hot water supply, the hot water supply path 5 and the hot water supply path 6 are communicated only via the main hot water supply apparatus 3a, and the other sub hot water supplies 3b, 3c, 3d,... Cut off the hot water supply path 5 and the hot water supply path 6 ( (Water cannot pass).

  If, for example, the hot water tap at the downstream end is opened and water enters the water inlet path 5 and the flow rate of water entering the main water heater 3a becomes MOQ or more, the combustion of the main water heater 3a is started and the hot water supply operation control (parallel When the hot water supply capacity of the main water heater 3a alone becomes insufficient for the hot water supply request amount, the main water heater 3a outputs a complement request to the system controller 2, and the system controller receiving the supplement request. 2 sends a combustion permission command to any one of the other sub-water heaters 3b, 3c,... Assigned as sub-water heaters (for example, 3c). Thereby, the flow control valve 44 of the sub water heater 3c is opened and the sub water heater 3c is burned together with the main water heater 3a by detecting the incoming water flow rate equal to or higher than MOQ by the incoming water flow sensor 41. If the required amount of hot water is insufficient even by the combustion of these two water heaters 3a and 3c, the number of combustion units is increased so that the other sub-water heater 3 (for example, 3d) is also burned. Similarly, when the hot water supply request decreases, the number of combustion units is sequentially reduced by sequentially transmitting the combustion prohibition commands in response to the request. The assignment of the role of the main water heater 3a is switched every time a predetermined time elapses, or switched in accordance with the cumulative combustion time of each water heater. One of the other water heaters 3b, 3c,... Assigned as the sub-water heater is newly assigned and set as the main water heater and stored in the setting storage unit 213.

  On the other hand, in parallel with the execution of the number control by the basic control unit 211 of the number control unit 21, the monitoring control of the main water heater is executed by the monitoring control unit 212. That is, as shown in FIG. 5, the fan control status of the water heater (for example, 3a) allocated to the main water heater is monitored, and more specifically, the individual controller 31 of the main water heater 3a determines that the cumulative correction amount is equal to the second predetermined value. It is monitored whether there is information output indicating that the value reaches the determination value (for example, the cumulative correction amount of 5%) (step S1). If there is an information output indicating that the main water heater 3a has been reached (YES in step S2), the setting of the main water heater 3a as the main water heater is released, and the assignment of the main water heater 3a as the main water heater is set. Although the assignment as a main water heater is prohibited by excluding it, the assignment as a sub-water heater is set and the use as a sub-water heater is permitted (step S3).

  With the release of the setting of the main water heater 3a as the main water heater, one of the other water heaters 3b, 3c,... Allocated as the sub water heaters is newly allocated and set as the main water heater. I do. At the time of the new main water heater allocation setting, an information output indicating that the above-mentioned second determination value has been reached is transmitted from each individual controller 31 to the system controller 2 irrespective of the main water heater or the sub water heater. In such a case, from among the other water heaters 3b, 3c,..., The water heater that has not output such information yet, that is, the degree of blockage of the air supply / exhaust flow path is the second water heater. Water heaters in the closed state (targets to which the main water heater can be allocated) corresponding to less than the determination value (5%) are selected. Further, during the subsequent hot water supply operation, the water heater 3a, whose allocation setting as the main water heater is released, is corrected to the second determination value of less than 5% due to, for example, the stop of the inflow of wind. If it can be confirmed by the detection of the fan current value that the required function (predetermined air supply amount) has recovered in the amount range, the prohibition of the setting of the water heater 3a as the main water heater is released, and the water heater 3a is released as the main water heater. It returns to the assignable target.

  In the case of the above-mentioned embodiment, in using hot water using the connected hot water supply system, it is possible to avoid running out of hot water as much as possible, and it is possible to continuously use the connected hot water supply system for a long time. Thereby, the user's comfort in using hot water can be improved. In other words, the main hot water heater plays the role of operating the hot water supply operation first when the hot water supply is used, and only one hot water supply operation is performed depending on the hot water supply request. In some cases, the cumulative correction amount reaches the upper limit value (first determination value) earlier than the sub water heater. If the forced operation is stopped while only one hot water supply system is being operated, running out of hot water, that is, interruption of the use of hot water supply, will be inevitable, resulting in inconvenience to the user. On the other hand, in the above-described embodiment, the allocation setting of the main water heater is released at a predetermined closing stage before the cumulative correction amount reaches the upper limit value. It can be avoided, and the possibility of inconvenience to the user can also be avoided. In addition, since the main water heater is released as a sub-water heater even after the setting of the main water heater is released, the hot water supply for a longer time is maintained while maintaining the original hot water supply capacity of the combined hot water supply system. Use can be continued.

<Other embodiments>
It should be noted that the present invention is not limited to the above-described embodiment, but includes various other embodiments. That is, in the above-described embodiment, an example is shown in which a connected hot water supply system is configured by two or more water heaters 3, 3,... And a system controller 2 that controls these water heaters. , And two or more units of a connected hot water supply system having a combination of a water heater and a system controller for controlling these units as one unit, and each system controller (slave system controller) of the connected hot water supply system of each unit is controlled. By providing a higher-level system controller (parent system controller), the present invention can be applied to a connected hot water supply system that constitutes a so-called hierarchical control system. In the above-described embodiment, the number of the main hot water heaters is one. However, the present invention is not limited to this. When the passage of water is detected, the water supply of the other main water heater is stopped and switched to the sub-water heater, and a control structure for concentrating the flow of water to the one main water heater where the passage of water is detected is provided. The present invention can be applied to a combined hot water supply system.

  In the above-described embodiment, each water heater 3 includes the fan control unit 311. The fan control unit 311 determines whether the supply / exhaust passage is closed based on the fan current value, and reduces the fan current value by a predetermined amount. The target rotation speed is increased and corrected by a predetermined ratio (1%) each time the error occurs, and the magnitude of the cumulative correction amount indicates the first determination level or the second determination level of the degree of blockage. The present invention is not limited to this, and it is possible to determine the blockage state using other detection parameters (for example, the temperature of the combustion flame) other than the fan current value, and to set the correction target to a control amount other than the target rotation speed, and The two determination levels can be represented by a correction amount other than the cumulative correction amount of the target rotation speed. In addition, although the correction amount for the rotation speed of the blower fan 40 is used as the first or second determination level, the present invention is not limited to this correction amount, and any other value that indicates the level of the degree of blockage may be used. Can be.

3, 3a, 3b, 3c, 3d, 3e, 3f Water heater 5 Water supply path 6 Water supply path 21 Number control unit 31 Fan control unit 40 Blower fan

Claims (3)

A plurality of hot water heaters respectively interposed in parallel between a water inlet path and a hot water outlet path, and the number of hot water heaters connected to the plurality of hot water heaters to perform hot water supply operation for the plurality of hot water heaters A plurality of water heaters, each of which controls a degree of blockage of the supply / exhaust passage, and when the degree of blockage increases to a predetermined first determination level, the hot water supply operation is forcibly stopped. One of a main water heater and a sub-water heater for operating the hot water supply first when the hot water supply is used for the plurality of water heaters. In the coupled hot water supply system, the role of the main hot water heater is rotated while being set alternately with any of the sub hot water heaters.
The number control unit cancels the allocation setting as the main water heater when the degree of blockage of the water heater allocated and set as the main water heater increases to a second determination level lower than the first determination level. and assignment set as a sub-water heaters Te, and one you prohibit be allocated set as the main water heater by excluding from the allocation set as the subsequent main water heater, the assignment setting as the main water heater If the degree of blockage of the prohibited water heater falls to a lower level range than the second determination level with the passage of time, the prohibition of the allocation setting is released and the allocation setting as the main water heater is permitted. Is configured to
A concatenated hot water supply system characterized in that: The combined hot water supply system according to claim 1,
The number control unit cancels the allocation setting as the main water heater, while the degree of blockage is in a lower level range than the second determination level from among the other water heaters allocated and set as the sub water heater. A combined hot water supply system configured to assign and set a hot water heater as a new main water heater. It is a connection hot-water supply system of Claim 1 or Claim 2 , Comprising:
Each of the plurality of water heaters includes a blower fan for supplying combustion air, and a fan control unit that controls an operation control amount of the blower fan,
The fan control unit is configured to increase and correct the target rotation speed of the blower fan by a predetermined ratio each time it is determined that a predetermined blocking situation has occurred,
The coupled hot water supply system, wherein the first determination level and the second determination level are specified corresponding to the cumulative ratio of the target rotation speed after the increase correction.

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