JP5458918B2 - Hot water system - Google Patents

Description

  The present invention relates to a hot water supply system, and more particularly to a hot water supply system in which a plurality of hot water heaters are connected in parallel to control the number of hot water heaters that perform a hot water supply operation according to the hot water supply capacity.

  Conventionally, in this type of hot water supply system, only one hot water heater is in a standby state in which water flow can be performed by opening the flow control valve (that is, in a hot water supply operation state), while the other hot water heaters are in flow control. When the valve is closed and the hot water supply capacity of one water heater is insufficient, the flow control valves of the second and subsequent water heaters are configured to open (number control of water heaters).

  However, in the configuration in which only one unit opens and waits for the hot water supply standby in this way, for example, if water flow cannot be detected due to a failure of the flow sensor of the water heater, the water heater will Not only cannot the operation be performed, but the number control does not function, so the second and subsequent hot water heaters cannot perform the hot water supply operation, and the entire hot water supply system falls into a state in which hot water supply cannot be performed.

  Therefore, recently, it has been proposed to use two (two or more) hot water heaters that stand by in a state where hot water supply operation is possible during hot water supply standby (see, for example, Patent Document 1).

JP-A-2-40445

  However, the configuration in which two or more hot water heaters are on standby during hot water supply standby has the following problems, and improvements have been desired.

  That is, when two or more water heaters are on standby in a state where hot water supply operation is possible at the time of hot water supply standby, the amount of water flowing through each water heater is dispersed when water is generated by opening the hot water tap or the like. Therefore, the amount of water passing through each water heater in the standby state is reduced. Therefore, for example, when there are two hot water heaters on standby, the minimum operating water flow amount of these water heaters (the minimum water flow amount set as a condition for the water heater to start a hot water supply operation (combustion operation)) is A [ L / min], these water heaters cannot start the hot water supply operation unless there is twice the water flow rate of 2A [L / min] or more. is there.

  The present invention has been made in view of such problems, and the object of the present invention is to delay the hot water supply even when two or more hot water heaters are on standby in a state where hot water supply operation is possible during hot water supply standby. There is no hot water system to provide.

  In order to achieve the above object, a hot water supply system according to claim 1 of the present invention is a hot water supply system in which a plurality of hot water heaters are connected in parallel and a controller for controlling the number of hot water heaters is provided. In a hot water supply system in which each water heater is provided with means for controlling water flow and means for detecting the amount of water flow, and the control unit controls to allow two or more water heaters to pass water during standby for hot water supply. The water flow rate per unit time among water heaters that can be made water is equal to or higher than a predetermined flow rate set in a region less than the minimum operating water flow rate of the water heater, and the accumulated water flow rate is a predetermined value. On the condition that it reaches the above, the control unit performs the water flow restriction control for reducing the water flow rate of other hot water heaters capable of water flow.

  In the hot water supply system according to claim 1, since there are two or more hot water heaters (hot water heaters in a state where water can flow) waiting in a state where hot water can be operated during hot water standby, Since the flowing water flow is dispersed, the accumulated water flow can be calculated from when the water heater has water flow that does not reach the minimum operating water flow rate (water flow that exceeds the specified flow rate set in the area below the minimum working water flow rate). taking measurement. And when this integrated value exceeds a predetermined value, the water flow is reduced to one water heater (a water heater whose integrated water flow exceeds the predetermined value) by reducing the water flow rate of other hot water heaters capable of passing water. Concentrate and direct the water flow rate of the water heater to exceed the minimum operating water flow rate so that the hot water supply operation by the water heater is started early. As a result, even when the amount of water flowing through the hot water heater that stands by in a state where hot water supply operation is possible is small, the hot water supply operation is started at an early stage, and a convenient hot water supply system can be provided.

  A hot water supply system according to claim 2 of the present invention is a hot water supply system in which a plurality of hot water heaters are connected in parallel and provided with a control unit for controlling the number of hot water heaters, and each hot water heater allows water to pass therethrough. A hot water heater comprising a means for controlling and a means for detecting the amount of water flow, wherein the control unit controls two or more water heaters to be in a state in which water can be passed at the time of hot water standby. Of these, the control unit has the following conditions on condition that the water flow rate per unit time is less than the minimum operating water flow rate of the water heater and that a predetermined time has passed in that state. The water flow restriction control is performed to reduce the water flow amount of the hot water heater capable of water flow.

  In the hot water supply system according to claim 2, water flow that is less than the minimum operating water flow amount is supplied to one of the water heaters (water heaters that are in a water flowable state) that waits in a state where hot water supply operation is possible during hot water supply standby. If so, measure the elapsed time in that state. When this elapsed time exceeds a predetermined time, the water flow is concentrated on one hot water heater (a water heater whose elapsed time has exceeded the predetermined time) by reducing the amount of water flow of other hot water heaters that can pass water. Thus, the water flow rate of the hot water heater is directed to exceed the minimum operating water flow rate at an early stage so that the hot water supply operation by the water heater is started early. As a result, even when the amount of water flowing through the hot water heater that stands by in a state where hot water supply operation is possible is small, the hot water supply operation is started at an early stage, and a convenient hot water supply system can be provided.

  The hot-water supply system according to claim 3 of the present invention is the hot-water supply system according to claim 1 or 2, wherein the amount of water flow in each hot water supply device through which water can pass during the period until the condition for performing the water flow restriction control is satisfied. When the difference is equal to or greater than a predetermined flow rate, the control unit performs water flow restriction control for reducing the water flow rate of the water heater having the smaller water flow rate.

  That is, in the hot water supply system according to claim 3, the amount of water flow in each hot water heater that can pass water is compared until the condition for performing the water flow restriction control in the hot water supply system according to claim 1 or 2 is established. . When the difference becomes equal to or greater than the predetermined flow rate, by reducing the water flow rate of the water heater having the smaller water flow rate, the water flow is concentrated on the water heater having the larger water flow rate, so that the water flow rate of the water heater becomes early. In order to exceed the minimum operating water flow rate, the hot water supply operation by the water heater is started early. Accordingly, in the hot water supply system adopting the configuration of claim 1 or 2, the amount of water flow is reduced by a factor that obstructs water flow such as garbage biting in one of the water heaters that are in a state where hot water can be operated. In such a case, the hot water supply operation can be started at an early stage with such a water heater that does not impede such water flow.

  A hot water supply system according to claim 4 of the present invention is a hot water supply system including a controller that connects a plurality of water heaters in parallel and controls the number of water heaters, and each water heater controls the flow of water. And a means for detecting the amount of water flow, and in a hot water supply system in which two or more hot water heaters can be passed during hot water supply standby, the difference in the water flow rate of each water heater that can pass water during the hot water standby is greater than or equal to a predetermined flow rate Then, the control unit performs the water flow restriction control for reducing the water flow rate of the water heater having the smaller water flow rate.

  In the hot water supply system according to claim 4, the water flow amounts of the hot water heaters (hot water heaters in a water flowable state) waiting in a hot water supply operation state during hot water standby are compared, and the difference in the water flow amount is equal to or greater than a predetermined flow rate. Then, by reducing the water flow rate of the water heater with the smaller water flow rate, the water flow is concentrated on the water heater with a larger water flow rate so that the water flow rate of the water heater exceeds the minimum operating water flow rate at an early stage. The hot water supply operation by the hot water heater is started early. Thus, for example, even when one of the hot water heaters that are in a state where hot water supply operation is possible is reduced in water flow rate due to a factor that impedes water flow such as dust biting, The hot water supply operation can be started with a hot water heater having no obstruction factor, and hot water can be secured at an early stage.

  A hot water supply system according to a fifth aspect of the present invention is the hot water supply system according to any one of the first to fourth aspects, wherein the water flow restriction control is a control for stopping the water flow of the water heater. To do. The hot water supply system according to claim 6 is characterized in that the stop of water flow by the water flow restriction control is performed by a closed flow control valve provided in the water heater.

  In the hot water supply system according to claim 5, in the hot water supply system adopting the configuration of claims 1 to 4, the water flow restriction control is a control for stopping the water flow of the water heater. The concentration effect of the water flow with respect to the non-hot water heater is enhanced, and the water flow rate of the water heater can be set to exceed the minimum operating water flow rate earlier.

  According to the present invention, it is possible to prevent a delay in the start of a hot water supply operation due to the use of two or more hot water heaters that are capable of passing water during standby for hot water supply (the amount of water flowing through the water heater is dispersed when water flows). Therefore, on condition that a certain condition is satisfied, the water flow rate of one of the water heaters in a state where water can be passed is reduced and the water flow rate of other water heaters capable of passing water is reduced. The water heater can be concentrated in one water heater, and the water heater in which the water flow is concentrated can obtain the water flow exceeding the minimum operating water flow amount at an early stage. Therefore, the hot water heater in which water flow is concentrated starts the hot water supply operation at an early stage, and can provide an easy-to-use hot water supply system.

  In addition, according to the present invention, since two or more hot water heaters are set in a state where water can be passed during the hot water standby, even if one flow sensor of the hot water heater in a state where water can be passed breaks down, While the entire system is prevented from falling into hot water supply, when the amount of water flow is small, water is concentrated in one water heater and the hot water supply operation is performed with the water heater. The number of hot water heaters to be used can be reduced, consumption of the water heater due to repeated combustion can be suppressed, and the durability of the entire hot water system can be improved.

It is a schematic structure figure showing an example of a hot-water supply system concerning the present invention. It is explanatory drawing which showed typically the relationship between the main water heater and sub water heater in the hot water supply system, FIG.2 (a) has shown an example of the setting of the main water heater at the beginning of unit control, FIG. FIG. 2B shows an example of changing the setting of the main water heater, and FIG. 2C shows another example of changing the setting of the main water heater.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1
FIG. 1 is a schematic configuration diagram illustrating an example of a hot water supply system according to the present invention. This hot water supply system is a hot water supply system mainly for business use installed in a place (for example, a hotel) where there is a large amount of hot water demand where a single hot water heater has insufficient hot water supply capacity. In this hot water supply system, a plurality of (for example, six) hot water heaters 1a to 1f, a system controller 2 that controls the number of the hot water heaters 1a to 1f, and a remote controller 3 that is an operating device of the hot water system are configured as main parts. Has been.

  Each of the water heaters 1a to 1f is a water heater provided with a heat exchanger 10, and is connected in parallel so as to share a water inlet pipe 4 connected to a water source and a hot water outlet pipe 5 connected to a hot water tap. It is connected. That is, the branch pipe 6 from the water inlet pipe 4 is connected to the water inlet side of the heat exchanger of each of the water heaters 1 a to 1 f, and the hot water outlet side of the heat exchanger is connected to the hot water pipe 5 via the hot water pipe 7. It is connected. Further, each water heater 1a to 1f has a closed flow rate control valve (means for controlling the water flow of the water heater) so that the water flow can be stopped when the hot water supply instruction from the system controller 2 is not received. 11 is provided.

  Each of the water heaters 1a to 1f is provided with a flow rate sensor (means for detecting the water flow rate) 12, and each of the water heaters 1a to 1f has its own flow rate sensor 12 and the water heater performs a combustion operation. When water flow exceeding a minimum flow rate (minimum operating water flow rate) set as a condition for starting is detected, a control unit (not shown) of the water heater is a combustion unit (not shown) of the water heater. Is configured to start hot water supply operation.

  The system controller 2 is a control device for controlling the number of hot water heaters 1a to 1f constituting the hot water supply system. In the present embodiment, the system controller 2 is built in the hot water heater 1a. The system controller 2 and the control units of the water heaters 1a to 1f are connected to each other, and the system controller 2 controls the water heaters 1a to 1f (specifically, the flow control valves 11 of the water heaters 1a to 1f). Control). In addition, about the water heater 1a in which the system controller 2 is built, the controller of the water heater may be configured to also serve as the system controller 2.

  Here, the outline of the number control of the water heaters 1a to 1f will be described. In controlling the number of water heaters in this type of water heater system, the system controller 2 sets a water heater (main water heater) to be operated first at the beginning of the hot water supply operation. In order to enable the main water heater to perform the hot water supply operation at the beginning of the hot water supply operation, the system controller 2 instructs the main water heater to open the flow control valve 11 of the hot water heater. Is given. Therefore, the water heater set as the main water heater is in a state where water can be passed, and water is generated by opening the hot water tap connected to the hot water system, and this water flow exceeds the minimum operating water flow rate. And automatically starts hot water supply operation.

  On the other hand, since a command to open the flow control valve 11 is not given from the system controller 2 to the hot water heaters (sub-water heaters) other than the main water heater, the water heater fully closes the flow control valve 11. It keeps in. For this reason, in the sub water heater, even if water flows through the main water heater by opening the hot water tap, the combustion section does not burn and the hot water supply operation is not performed.

  By the way, although the number of main water heaters set by the system controller 2 may be one, in the present embodiment, two or more (for example, two) water heaters are set as the main water heaters. Specifically, as shown in FIG. 2 (a), in this embodiment, the system controller 2 sets the water heaters 1a and 1b as main water heaters before the start of the hot water supply operation, and sets the other water heaters 1c to 1c. 1f is a sub-water heater. In FIG. 2, “main 1” and “main 2” mean the main water heater, and “standby” means the sub-water heater. In addition, “open” and “fully closed” displayed in the lower column indicate the operating state of the flow control valve 11.

  Note that the system controller 2 sets the main water heater in the present embodiment on the assumption that the operation switch of the remote controller 3 (a switch that enables the hot water supply system) is turned on. Since there are two heaters, there are at least two normal water heaters, and neither of the two water heaters to be set as main water heaters detects water flow (for example, the flow rate of the water heaters). <1 [L / min]).

  In this way, when the hot water tap is opened in the state where the main water heater and the sub water heater are set, first, water flows through the main water heater, and the hot water supply operation by the main water heater is started. . When the hot water supply flow increases or the hot water supply temperature is set high during the hot water supply operation by the main water heater, the hot water supply load increases, and when the main water heater alone cannot respond to the hot water supply load, the system controller 2 In response to this, a command to open the flow control valve 11 is given to one of the sub water heaters. Thereby, water flow also occurs in the sub water heater, and the sub water heater also starts the hot water operation.

  Thereafter, in response to the increase in hot water supply load, the system controller 2 gives a command to sequentially open the flow rate control valve 11 to the second and subsequent sub water heaters to cope with the increase in hot water supply load. On the other hand, when the hot water supply load decreases, on the contrary, in response to the decrease in the hot water supply load, the system controller 2 gives a command to close the flow control valve 11 in order from the sub water heater, Control to reduce the number of water heaters in operation sequentially (number control of water heaters).

  The remote controller 3 is an operating device for operating the hot water supply system, and is connected to the system controller 2 in communication. In addition to the above-described operation switch, the remote controller 3 is provided with various operation switches such as a switch for setting a hot water supply set temperature, and a display unit for confirming the state of the hot water supply system.

  Next, details of the control of the number of water heaters in the hot water system configured as described above (particularly, the change of the main water heater) will be described with reference to FIG.

  In the following description, it is assumed that the water heaters 1a and 1b are set as the main water heaters at the beginning of the hot water supply operation (more precisely, at the time of standby for hot water before the main water heater starts the hot water supply operation). To do.

  The system controller 2 monitors the amount of water flow per unit time for both the main water heaters 1a and 1b from the time when the main water heaters 1a and 1b are both in the hot water supply standby state where the hot water supply operation has not started. This monitoring is performed when the system controller 2 acquires the detection value of the flow sensor 12 provided in each main water heater 1a, 1b through the control part of each water heater 1a, 1b.

  When water flow occurs in at least one of the main water heaters 1a and 1b, the system controller 2 integrates the amount of water flow per unit time of the water heater in which the water flow has occurred. Calculate the water flow amount A. Specifically, the system controller 2 sets a predetermined flow rate B (for example, B = 1 [for example] in a region where the water flow rate per unit time of the main water heater 1a or 1b is less than the minimum operating water flow rate of the water heater. L / min]) or more, it is determined that there is water passing through the water heater, and integration is started. This integration is continued even if the water flow to the main water heater 1a or 1b exceeds the minimum operating water flow rate, but if the water flow stops during the integration (for example, the water flow rate <1 [L / min] can be obtained). The integration is canceled (that is, the integration value = 0).

  Then, the system controller 2 compares the accumulated water flow amount A with a predetermined threshold value (predetermined value) X1 set in advance, and if the accumulated water flow amount A becomes equal to or greater than the threshold value X1 (that is, A ≧ If it becomes X1, the water flow restriction control for reducing the water flow rate of the main water heater other than the water heater that satisfies this condition is performed. For example, when the main water heater 1a satisfies this condition (A ≧ X1), the hot water heater 1b that is another main water heater is controlled to reduce the amount of water flow (water flow restriction control), and the hot water supply that satisfies the condition Concentrate the water flow on the vessel 1a.

  Thereby, when the water flow rate per unit time of the main water heater 1a does not reach the minimum operating water flow rate, the water flow rate of the water heater 1a is set to exceed the minimum operating water flow rate. That is, the water flow that has been dispersed due to the presence of the two main water heaters is concentrated in one main water heater 1a, and the main water heater 1a can immediately start the hot water supply operation (exceeding the minimum operating water flow rate). Water can be obtained).

  Even when one or both of the main water heaters 1a and 1b obtain the minimum operating water flow rate, the system controller 2 continues to accumulate the water flow rate. When the above condition (A ≧ X1) is satisfied by the water heater, control (water flow restriction control) is performed to reduce the water flow amount of the other main water heaters. That is, in this case, only one water heater is operated as a main water heater, and the other water heater is not controlled until the instruction from the system controller is given by the number control. For example, even if the main water heaters 1a and 1b both obtain water flow exceeding the minimum operating water flow rate and start the hot water supply operation, if the above condition (A ≧ X1) is satisfied in one main water heater 1a, the other main The water heater 1b stops the hot water supply operation and performs the hot water supply operation only with one main hot water heater 1, and the other water heater 1b is incorporated in the number control of the system controller 2 thereafter. Based on the hot water supply operation.

  On the other hand, when the accumulated water flow amount A of each main water heater 1a, 1b is less than the above threshold value X1 (both main water heaters 1a, 1b are in a state of A <X1), during this period, the system The controller 2 determines whether there is a bias in the water flow of the main water heaters 1a, 1b (in other words, whether there is a factor that inhibits water flow such as dust biting in one of the water heaters). (Determination of water flow bias in the main water heater).

  This water flow bias determination is performed using the water flow rate (or integrated water flow rate A) per unit time of the main water heaters 1a and 1b. Specifically, the system controller 2 determines that the water flow rate per unit time (or its accumulated water flow rate A) of one of the main water heaters is equal to or greater than a predetermined threshold value X2, as this determination. And determination of whether the amount of water flow per unit time of the other water heater (or its accumulated water flow amount A) is less than a predetermined threshold value X3 (or whether this state is continued for a predetermined time C or more). When these conditions are satisfied, it is determined that there is a bias in the water flow of the main water heater, and a process of removing a water heater with a small amount of water flow from the setting of the main water heater is performed.

  That is, in this case, the system controller 2 closes the flow control valve 11 of the main water heater (for example, the water heater 1a) with a small amount of water flow and removes the water heater 1a from the main water heater so far. The water heater (for example, the water heater 1c) that has been set as the main water heater at the start of the next hot water supply. The threshold values X2 and X3 are X2> X3 (for example, X2 = 3 [L / min], X3 = 6 [L / min]).

  As a result, the water heater with a water flow impediment factor such as garbage biting is not left as it is set as the main water heater, and the water heater with the water flow impediment factor is operated as a main water heater. It can be avoided. In relation to this determination, the threshold value X1 in the water flow restriction control described above is preferably as small as possible in order to start the hot water supply operation at an early stage. If it is set too small, there will be no time margin for determining the deviation of water flow in the main water heater, so the value of the threshold value X1 is appropriately set so that this determination can be made.

  As described above, in the hot water supply system of the present embodiment, since two or more main hot water heaters are set during hot water supply standby, even if one flow rate sensor of the main hot water heater fails, the entire hot water supply system cannot be supplied. Since the system controller 2 performs control so that the number of main water heaters that perform hot water supply operation at the beginning of hot water supply is limited to one, consumption of the main water heater that does not perform hot water supply operation is suppressed. The durability of the hot water supply system as a whole can be improved.

  In this embodiment, since two or more main water heaters are set, for example, when controlling the number of units, the system controller 2 sets the minimum operating water flow rate in any one of the main water heaters at the start of water flow. When exceeding water flow is obtained, it is also possible to perform control (water flow restriction control) for reducing the amount of water flow of other hot water heaters other than the water heater.

  That is, when water flow exceeding the minimum operating water flow rate is obtained (detected) in two or more water heaters at the beginning of water flow, it is determined that at least the flow sensor 12 of the main water heater has not failed. So, except for the case where one water heater alone is not enough, the main water heater leaves only one water heater, reducing the water flow to other water heaters, thereby reducing the water flow It is also possible not to perform the hot water supply operation (combustion operation) for the hot water heater that is made to operate. Also in this case, since the number of times of combustion (consumption of the combustion section, etc.) is suppressed for the water heater in which the hot water supply operation (combustion operation) is avoided, the durability of the entire hot water supply system can be improved.

  Moreover, in this embodiment, since the shut-off type flow control valve is used for the flow control valve 11 of each of the water heaters 1a to 1f, the flow control valve 11 is closed in the above-described water flow restriction control (fully closed). Control can also be performed. Thereby, the water heater 1b which was the main water heater is switched from the main water heater to the sub water heater (see FIG. 2B). That is, the system controller 2 sets the water heater 1b as a sub water heater by fully closing the flow rate control valve 11 of the water heater 1b, and controls the number of water heaters thereafter (change of the main water heater). . In this case, the system controller 2 opens the flow rate control valve 11 of the water heater 1b when the main water heater 1a alone has insufficient hot water supply capacity.

  In addition, the water heater 1b which became the sub water heater by performing the control to fully close the flow rate control valve 11 in the water flow restriction control (the water heater made into the sub water heater by the determination of the flow unevenness of the main water heater) In the subsequent control of the number of units, the order of opening the flow rate control valve 11 as a sub water heater may be set later (preferably the last) than the other sub water heaters 1c to 1f. That is, in this case, since the increase in the accumulated water flow rate A of the water heater 1b is delayed from the water heater 1a, for example, the biting of dust in the pipe can be considered, so that the water heater 1b has less chance of performing the hot water operation. However, it is possible to reduce the burden on the hot water supply system as a whole (increase in the number of water heaters that perform hot water supply operation).

Embodiment 2
Next, another embodiment of the present invention will be described. The hot water supply system shown in this embodiment is a modification of the method of determining the water flow bias of the main water heater in the hot water supply system shown in the first embodiment, and the other points are common to the first embodiment. Therefore, parts having the same configuration are denoted by the same reference numerals and description thereof is omitted.

  That is, in this embodiment, in the above-described first embodiment, during the hot water supply standby state, a state in which water can be passed as the main water heater during a period until the condition that the accumulated water flow amount A ≧ X1 is satisfied in any of the main water heaters. The system controller 2 monitors the difference D in the amount of water flow between the water heaters 1a and 1b, and the deviation D is equal to or greater than a predetermined threshold value (predetermined flow rate) Y (that is, D ≧ Y). The system controller 2 is configured to perform water flow restriction control for reducing the water flow rate of the water heater having the smaller water flow rate.

  For example, if the main water heater 1b has a factor that impedes water flow, such as the biting of dust in a pipe, if the hot-water tap is opened in this state, before the condition (A ≧ X1) described in the first embodiment is satisfied. Even if it exists, the difference D will arise in the amount of water flow with the main water heater 1a without a water flow obstruction factor, and the main water heater 1b with a water flow obstruction factor. In the hot water supply system of the present embodiment, when the difference D is equal to or greater than a predetermined flow rate Y set in advance, the water flow restriction control for reducing the water flow rate of the water heater 1b having the smaller water flow rate is performed. Similarly to the water flow bias determination, it is possible to avoid the hot water supply having a water flow impediment factor becoming the main water heater and starting the hot water supply operation.

  In the present embodiment as well, as in the first embodiment described above, the system controller 2 is configured such that when water flow exceeding the minimum operating water flow rate is obtained in any one of the main water heaters at the start of water flow. Can be configured to perform the water flow restriction control for reducing the water flow rate of a hot water heater other than the water heater. In addition, since a closed flow control valve is used as the flow control valve 11 of the water heaters 1a to 1f, the flow control valve 11 can be closed in the water flow restriction control. A hot water heater with a sub-water heater can be used. And in that case, the hot water heater 1b used as the sub water heater sets the order which opens the flow control valve in subsequent number control to the back (preferably last) of the other sub water heaters 1c-1f. It is good.

Embodiment 3
Next, another embodiment of the present invention will be described. The hot water supply system shown in this embodiment is obtained by changing the execution conditions of the water flow restriction control in the hot water supply system shown in the first embodiment, and the other points are common to the first embodiment. Therefore, parts having the same configuration are denoted by the same reference numerals and description thereof is omitted.

  Also in the hot water supply system shown in this embodiment, the system controller 2 is a unit for both the main hot water heaters 1a and 1b from when the main hot water heaters 1a and 1b are in the hot water supply standby state where the hot water supply operation is not started. Monitor water flow per hour. This monitoring is also performed by the system controller 2 acquiring the detection value of the flow rate sensor 12 provided in each main water heater 1a, 1b through the control unit of each water heater 1a, 1b, as in the first embodiment. .

  When water flow occurs in one of the main water heaters 1a and 1b, the system controller 2 indicates that the water flow rate per unit time of the water heater in which water flow has occurred is less than the minimum operating water flow rate. The time E (that is, the elapsed time of water flow that does not satisfy the minimum operating water flow rate) E is measured. If the water flow stops during this measurement (for example, if the water flow rate <1 [L / min]), the measurement of the elapsed time E is canceled (ie, the elapsed time E = 0). Further, when there is water flow exceeding the minimum operating water flow rate in any one of the main water heaters 1a and 1b during this measurement, the measurement is similarly canceled.

  Then, the system controller 2 compares the elapsed time E with a predetermined threshold value (predetermined time) Z set in advance, and if the elapsed time E exceeds the threshold value Z (that is, E> Z). For example, the water flow restriction control is performed to reduce the water flow rate of the main water heater other than the water heater that satisfies this condition. For example, assuming that the main water heater 1b satisfies this condition (condition of E> Z), the water heater 1a that is another main water heater is controlled to reduce the amount of water flow (water flow restriction control), and the condition The water flow is concentrated on the water heater 1b that satisfies the above conditions so that the water flow rate of the water heater 1b exceeds the minimum operating water flow rate. As a result, the water flow that has been dispersed due to the presence of the two main water heaters is concentrated in one main water heater 1b, and the main water heater 1b can quickly start the hot water supply operation (the minimum operating water flow rate is reduced). Exceeding water flow).

  The threshold value Z can be set as appropriate. If this threshold value Z is set too large, the delay in the hot water supply operation due to the dispersion of water flow due to the use of two main water heaters will continue over a long period of time. It is preferable to set as small as possible based on this.

  As described above, in the hot water supply system of the present embodiment as well, as in the first embodiment, two or more main hot water heaters are set during hot water supply standby, so even if one flow sensor of the main hot water heater fails, The system can prevent the entire system from falling into hot water supply, and when the amount of water flow is small, only one hot water heater is required to perform hot water supply operation. The heater can suppress consumption due to combustion, and the durability of the hot water supply system as a whole can be improved.

  And also in this embodiment, similarly to Embodiment 1 mentioned above, when there is water flow exceeding the minimum operating water flow rate in any one of the main water heaters at the start of water flow, the system controller 2 It can comprise so that the water flow restriction | limiting control which reduces the water flow amount of the hot water heaters other than the said water heater can be passed. Moreover, since a shut-off type flow control valve is used for the flow control valve 11 of the water heaters 1a to 1f, it is preferable to close the flow control valve 11 in the water flow restriction control. And also in this embodiment, as shown in Embodiment 1 or 2, it is comprised so that the water flow bias determination of a main water heater may be performed before the execution conditions (E> Z) of water flow restriction control are satisfied. You can also.

  The above-described embodiments show preferred embodiments of the present invention, and the present invention is not limited to these, and various design changes can be made within the scope of the invention.

  For example, in the above-described embodiment, the flow control valve 11 is controlled to be closed (fully closed) as the water flow restriction control. However, the water flow restriction control reduces the water flow amount of the target water heater. The control is not limited to the control that fully closes the flow control valve 11.

  Moreover, in Embodiment 2 mentioned above, the deviation D of the water flow amount between main water heaters on the conditions of integrated water flow amount A> = predetermined value X1 shown in Embodiment 1 as the execution condition of the water flow restriction control by the system controller 2. Although the case where the condition that the flow rate becomes equal to or higher than the predetermined flow rate Y (that is, D ≧ Y) is shown, the condition (D ≧ Y) can be used alone. That is, the system controller 2 monitors the flow rate difference D of the main water heater during hot water supply standby, and if this difference D exceeds a predetermined flow rate Y, the flow rate of the hot water heater with the smaller flow rate is decreased. It can also be configured to perform water restriction control. In this case as well, the flow rate control valve 11 may be closed by the water flow restriction control, and the water heater that becomes the sub-water heater thereby changes the order of opening the flow rate control valve in the subsequent number control. It may be set after the sub-water heater (preferably at the end).

1a to 1f Water heater 2 System controller (control unit for controlling the number of units)
3 Remote control 4 Water inlet pipe 5 Hot water outlet pipe 10 Heat exchanger 11 Flow rate control valve (means for controlling water flow through the water heater)
12 Flow rate sensor (means to detect water flow rate)

Claims (6)

A hot water supply system in which a plurality of water heaters are connected in parallel and includes a control unit that controls the number of water heaters, each water heater includes means for controlling water flow and means for detecting the amount of water flow. In the hot water supply system in which the controller controls two or more hot water heaters to be in a state capable of passing water during standby for hot water supply,
Of the water heaters that are allowed to pass water during the hot water standby, the amount of water flow per unit time is equal to or greater than the predetermined flow rate set in the area below the minimum operating water flow rate of the water heater, and A hot water supply system in which the control unit performs water flow restriction control for reducing the water flow rate of another hot water heater capable of passing water on condition that the water amount reaches a predetermined value. A hot water supply system in which a plurality of water heaters are connected in parallel and includes a control unit that controls the number of water heaters, each water heater includes means for controlling water flow and means for detecting the amount of water flow. In the hot water supply system in which the controller controls two or more hot water heaters to be in a state capable of passing water during standby for hot water supply,
Of the hot water heaters that are allowed to pass water at the time of hot water supply standby, the water flow rate per unit time is less than the minimum operating water flow rate of water heaters, but the specified time has passed in that state. On the condition that it does, the hot water supply system characterized by performing the water flow restriction control which the said control part reduces the water flow rate of the other hot water heater which can be passed.   If the difference in the amount of water flow in each hot water heater that can pass water is equal to or greater than a predetermined flow rate until the condition for performing the water flow restriction control is satisfied, the flow rate of the water heater with the smaller water flow rate is controlled by the control unit. The hot water supply system according to claim 1 or 2, wherein water flow restriction control is performed to reduce the water flow. A hot water supply system comprising a control unit for connecting a plurality of water heaters in parallel and controlling the number of water heaters, each water heater comprising means for controlling water flow and means for detecting the amount of water flow, In a hot water supply system that allows two or more water heaters to pass through during standby,
When the difference in the water flow amount of each water heater that can pass water during standby for hot water supply is equal to or greater than a predetermined flow rate, the control unit performs water flow restriction control that reduces the water flow rate of the water heater with the smaller water flow rate. Hot water system.   The hot water supply system according to any one of claims 1 to 4, wherein the water flow restriction control is a control for stopping water flow of the water heater.   The hot water supply system according to claim 5, wherein the stoppage of water flow by the water flow restriction control is performed by a closed flow rate control valve provided in a water heater.

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