JP2012032042A - Hot water supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water supply system capable of avoiding that a hot water supply destination becomes an excessively high temperature state due to hot water supply operation of each water heater by emergency operation even when communication between an upper control unit and a lower control unit is cut off.SOLUTION: When it is detected that communication between a parent system controller PSC and child system controllers SC1, SC2 is cut off, set hot water tapping temperature is selectively change-switched based on thermostat installation information by emergency operation control on the child system controller side. As the following emergency operation, while only a first pump 53 is continuously operated, burning operation of each water heater 3 at a set hot water tapping temperature after switching is continued to continue circulation heating to a hot water storing tank 6.

Description

  The present invention includes a lower control unit that controls the number of two or more hot water heaters that are interposed in parallel between a water inlet route and a hot water outlet route, and a higher control unit that controls the lower control unit. In particular, the present invention relates to a control technique that can prevent the hot water temperature from becoming excessively high during emergency operation when communication between the upper control unit and the lower control unit is interrupted.

  Conventionally, two or more units of a connected hot water system, each of which is a combination of a predetermined number of hot water heaters of two or more and a subordinate system controller that controls them, and controls each subordinate system controller of these hot water systems. There has been proposed a hot water supply system that includes a so-called hierarchical control system by including a target upper system controller (see, for example, Patent Document 1).

  Moreover, although the hierarchical control system is not adopted, in Patent Document 2, even if communication between the water heater and the remote control is not possible, the use history of communication with the remote control in the past is stored in the nonvolatile memory. In the case of remaining, there has been proposed a hot water supply device that performs hot water supply operation at a set continuous use temperature set in advance as a temperature value lower than the high temperature set temperature.

  Further, like the above, the hierarchical control system is not adopted. However, in Patent Document 3, the hot water in the hot water storage tank is circulated by a circulation pump and heated by a combustion burner built in the upper part of the hot water storage tank. In the hot water supply system, it has been proposed to detect the temperatures of the upper, middle and lower portions of the hot water storage tank and to control the operation of the combustion burner and the circulation pump so that the temperature difference between them is maintained within a certain range.

JP 2002-71217 A JP 2001-289502 A Japanese Patent No. 2511898

  By the way, by adopting a hierarchical control system, the scale of the connected hot water supply system is increased, and a high-temperature hot water storage system that quickly stores a large amount of hot water in a hot water storage tank Even if the communication connection between the control unit and the subordinate control unit is interrupted, it is possible to make an emergency operation so that the system does not go down (the system that does not burn even if there is a hot water supply request) It becomes important. In the hot water storage, the hot water in the hot water storage tank is introduced into a water intake path where a plurality of water heaters are connected in parallel by the operation of the circulation pump, and after being heated by the water heater, it is returned to the hot water storage tank through the hot water supply path. Although it is realized by executing the circulation operation, in the emergency operation, how to set the set hot water temperature that affects the combustion amount in each of the hot water heaters is particularly problematic.

  That is, in order to maintain the hot water storage temperature in the hot water storage tank within a certain range, when the temperature is lowered to a set lower limit temperature (for example, 60 ° C.), the circulating pump is operated and circulated and heated by each hot water supply. When the temperature reaches (° C.), the operation control is performed to stop the operation of the circulation pump. On the other hand, a temperature higher than the set upper limit temperature (eg, 75 ° C.) It is considered that the set hot water temperature is output from the upper control unit to the lower control unit, and a command relating to the set hot water temperature is issued from the lower control unit to each water heater, so that hot water can be stored quickly.

  However, in such a hot water supply system, for example, when the upper control unit breaks down or communication with the lower control unit is interrupted, the temperature of the hot water stored in the hot water storage tank due to circulation heating becomes excessively high. There is a risk of becoming. When the upper control unit breaks down, communication with the lower control unit is interrupted, so the lower control unit executes emergency operation control for each water heater independently of the upper control unit. If communication interruption occurs, output of the hot water storage temperature in the hot water storage tank and output of commands related to the set hot water temperature will be interrupted by the upper control unit, so the lower control unit will set the set hot water set so far as emergency operation. Based on the temperature, the combustion operation of each water heater is continued. If the operation of the circulation pump is continued and the circulating heating is continued in the high temperature hot water state in such a combustion operation state, the temperature of the hot water in the hot water storage tank exceeds the original set upper limit temperature and is excessively high. It will become.

  In addition, an instant hot water circulation circuit is formed with the incoming water route and the hot water route as a part of the circulation route, and is heated by circulation by the operation of the circulation pump to fill the immediate hot water circulation circuit with hot water in a predetermined high temperature state. In the case of leaving them, the same inconveniences as described above occur.

  The present invention has been made in view of such circumstances, and the purpose of the present invention is to provide each hot water supply by emergency operation even when communication between the upper control unit and the lower control unit is interrupted. An object of the present invention is to provide a hot water supply system capable of avoiding an excessively high temperature of the hot water supply destination due to the hot water supply operation of the water heater.

  In order to achieve the above object, the present invention includes a plurality of water heaters interposed in parallel between a water inlet path and a hot water outlet path, and a control unit that controls the plurality of water heaters. The following specific items were prepared for the hot water supply system. That is, the upper control unit that receives and obtains the output of the remote control set temperature set in the remote control from the remote control, and the lower control unit that obtains the set hot water temperature based on the remote control set temperature and the system configuration information related to the system configuration from the upper control unit by communication And a control unit. When the occurrence of communication interruption is detected between the upper control unit and the communication interruption detection unit that detects that communication with the upper control unit has been interrupted as each lower control unit. It is assumed that an emergency operation control unit that performs emergency operation control independently of the host control unit is provided. Then, as the emergency operation control unit, a set hot water temperature acquired last from the host control unit or a limit temperature that is stored in advance and limited to a predetermined temperature or less is selected based on the system configuration information. The hot water control by each hot water heater is executed with the selected temperature as the set hot water temperature in the emergency operation (claim 1).

  In the case of the present invention, when the occurrence of communication interruption due to failure of the upper control unit or disconnection of the communication line is detected by the communication interruption detection unit, the emergency hot water control unit obtains the set hot water last obtained from the upper control unit Either a temperature or a limit temperature that is stored in advance and limited to a predetermined temperature or less is selected based on the system configuration information, and hot water control in each water heater is performed with the selected temperature as a set hot water temperature in emergency operation. Will be executed. For this reason, the hot water supply operation is performed based on the changed set hot water temperature according to the system configuration information. Thus, in a normal state, hot water supply is performed quickly based on the set hot water temperature set at a high temperature, and even if communication is interrupted, the hot water supply operation is continued at the set hot water temperature set at the high temperature set regardless of the system configuration. Compared to the case where the hot water supply operation is performed by the hot water supply operation of each hot water heater by the emergency operation, it is possible to avoid the hot water supply destination from being excessively heated. In addition to the upper limit temperature value set and stored in advance, as the “limit temperature”, a subtracted temperature value obtained by subtracting a predetermined temperature value from the set hot water temperature acquired last before the interruption of communication is used. It may be used.

  In the present invention, a circulation pump, a hot water storage tank, and a thermostat that outputs a contact signal to the upper control unit based on the hot water storage temperature in the hot water storage tank are provided, and hot water in the hot water storage tank is supplied by the operation of the circulation pump. It is configured so that circulation heating is performed such that water is introduced into the water intake path and returned to the hot water storage tank through the hot water supply path after being heated by the water heater, and the system configuration information is the thermostat installation information regarding the presence or absence of the thermostat. In addition, the emergency operation control unit may be configured to switch the set hot water temperature by selecting the limit temperature when the system configuration information includes thermostat installation. By doing in this way, even if the communication interruption occurs in the hot water supply system configured so that the hot water temperature in the hot water storage tank is maintained in a predetermined hot water storage temperature management range by a thermostat in a normal state. The hot water storage temperature in the hot water storage tank is prevented from falling into an excessively high temperature state.

  In addition, the lower control unit is configured by a lower central control unit that performs communication control with the plurality of water heaters and controls the number of units that are burned for the plurality of water heaters, and serves as the upper control unit. The lower central control unit can be configured by an upper central control unit that is individually connected to the lower central control unit and performs overall control of the lower control unit. Further, the upper control unit is configured by a central control unit that is connected to the plurality of water heaters and performs operation control on the plurality of water heaters. The lower control unit includes each of the water heaters. In addition, it can be configured by an individual control unit that individually controls each water heater. In any hot water supply system, the operation of the present invention can be obtained.

  As described above, according to the hot water supply system of the present invention, even if communication interruption due to failure of the upper control unit or disconnection of the communication line or the like occurs, the emergency operation control unit lastly from the upper control unit. Either the acquired set hot water temperature or the limit temperature that is stored in advance and limited to a predetermined temperature or less is selected based on the system configuration information, and the selected hot water temperature is set as the set hot water temperature in the emergency operation. Since the hot water supply control is performed in the system, it is possible to switch to and change the appropriate set hot water temperature in the emergency operation depending on the system configuration information, and perform the hot water supply operation based on the changed hot water temperature set after the change. Will be able to. Thus, in a normal state, hot water supply is performed quickly based on the set hot water temperature set at a high temperature, and even if communication is interrupted, the hot water supply operation is continued at the set hot water temperature set at the high temperature set regardless of the system configuration. As compared with the case where the hot water is supplied, the hot water supply operation of each water heater by the emergency operation can surely avoid the hot water supply destination from falling into an excessively high temperature state.

  In particular, according to the present invention, a circulation pump, a hot water storage tank, and a thermostat that outputs a contact signal to the upper control unit based on the hot water storage temperature in the hot water storage tank are provided. In the hot water supply system configured to be performed, even if a communication interruption occurs by selecting the limit temperature as the set hot water temperature based on the thermostat installation information and switching the set hot water temperature, It becomes possible to reliably avoid the hot water storage temperature from falling into an excessively high temperature state.

  Moreover, according to Claim 3 or Claim 4, the high-order control part and low-order control part in the hot-water supply system of this invention are specified specifically, and the effect by this invention can be acquired in a specific hot-water supply system. become able to.

It is a mimetic diagram showing a 1st embodiment of a hot-water supply system of the present invention. It is a schematic diagram which shows the structural example of each water heater applied to the hot water supply system of FIG. It is a control block diagram of the hot water supply system of FIG. It is a flowchart which concerns on the emergency control in each child system controller of the hot-water supply system of FIG. It is a flowchart which concerns on the emergency control in the parent system controller of the hot-water supply system of FIG. It is a schematic diagram which shows 2nd Embodiment of the hot water supply system of this invention.

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

<First Embodiment>
FIG. 1 shows a hot water supply system according to a first embodiment of the present invention. This hot water supply system is a combination of two or more sets of unit hot water systems 2 (two sets in the illustrated example) in which control such as unit control is executed by a lower control unit. This is a connected hot water supply system to which a hierarchical control system is applied so as to be controlled by a control unit. Each unit hot water supply system 2 includes two or more predetermined number of hot water heaters 3, 3,... Controlled by a child system controller SC1 or SC2 as a lower control unit or a lower central control unit. The path 52 is connected in parallel. In addition, in the example of the figure, the case where each unit hot water supply system 2 is configured by six water heaters 3, 3,..., Is shown in order, 3a, 3b,. Is also attached. In this embodiment, a circulation path is formed by the water inlet path 51 and the hot water outlet path 52, and hot water in the hot water storage tank 6 is supplied from the lower part by the operation of the circulation pump 53 and / or 54 interposed in the circulation path. Is supplied to the hot water heaters 3, 3,..., Heated by the hot water heaters 3, 3,..., And then returned to the upper part of the hot water storage tank 6 through the hot water supply passage 52 to circulate and heat the hot water in the hot water storage tank 6. It is like that.

  Each water heater 3 constituting each hot water supply system 2 has a water inlet 32 connected to a water inlet path 51, while each outlet 33 is connected to a water outlet path 52. Between them. In each hot water supply system 2, each water heater 3 is subjected to hot water supply operation control mainly based on operation control of the combustion system by an individual controller 31 incorporated in each water heater 3, and the individual controller 31 of each water heater 3 is a sub system. Each individual controller 31 is connected to the controller SC1 or SC2 for communication, and receives control signals from the child system controller SC1 or SC2 mainly relating to operation setting in the unit control and setting of the set hot water temperature. Then, the child system controllers SC1 and SC2 of each hot water supply system 2 are individually connected to the parent system controller PSC as the upper control unit or the upper central control unit via the communication lines 71 and 72, and each child system controller SC1 or The SC 2 is configured to receive transmission of signals related to various information from the parent system controller PSC. That is, as a signal to be received, connection information indicating that the parent system controller PSC has been connected and information relating to hot water storage control of the hot water storage tank 6 is provided with a thermostat 61 described later, and control based on the thermostat 61 is performed. , A setting signal indicating which unit hot-water supply system 2 waits for the first hot-water supply operation, and a command signal related to the remote control set temperature input and set in the remote controller RC. The child system controllers SC1 and SC2 store these pieces of information in a nonvolatile memory (EEPROM) so that the stored information is not lost when the power is turned off and the system is restarted.

  Each of the child system controllers SC1 or SC2 and the individual controllers 31, 31,... Of each of the hot water heaters 3 constituting each unit hot water supply system 2 are connected to each other by a communication connection line 73 or 74 so as to be capable of bidirectional communication. By this connection, each child system controller SC1 or SC2 is connected to the number of connected water heaters 3, 3,... Constituting each unit hot water system 2 (six in the illustrated example), and each of the water heaters 3a, 3b... 3g, 3h,..., While each individual controller 31 is not a single installation type but a connection type by the above connection, and controls the operation based on a control command from the child system controller SC1 or SC2. Recognizing this, for example, it is stored in a non-volatile memory. Further, the individual controllers 31, 31,... Belonging to each unit hot water supply system 2 receive the output of the remote controller set temperature as the set hot water temperature from each child system controller SC1 or SC2, and execute the combustion operation control based on the remote controller set temperature. It is supposed to be. That is, the remote controller set temperature input and set in the remote controller RC is output to the parent system controller PSC, and is output from the parent system controller PSC to the child system controllers SC1 and SC2, and then the remote system setting is performed from the child system controllers SC1 and SC2. The temperature is output to each individual controller 31 as the set hot water temperature. Further, each of the individual controllers 31, 31,... Is provided with a power supply board, and receives a power supply current from power supply lines 75, 76 for supplying power to each water heater 3 via the power supply board.

  The example of each water heater 3 which comprises each said unit hot water supply system 2 is demonstrated. FIG. 2 shows a gas water heater that burns gas as fuel as an example of the water heater 3. In addition, the water heater 3 illustrated in FIG. 2 heats the incoming water from the water inlet 32 by combustion heat, and discharges the heated hot water from the outlet 33, and has such a function. For example, the unit hot water supply system 2 of the present invention can be configured using another type 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 includes a heat exchanger 34, a water inlet 35 that allows water from the water inlet path 51 to enter the heat exchanger 34 through the water inlet 32, and a hot water outlet 33 that supplies hot water heated by the heat exchanger 35. As a combustion section for heating the heat exchanger 34 with combustion heat, a bypass path 37 for mixing water with the hot water discharged from the heat exchanger 34, and a hot water discharged from the heat exchanger 34. And a combustion burner 38.

  The water inlet 35 is provided with an incoming water flow sensor 39 for detecting the incoming water flow rate and an incoming water temperature sensor 40 for detecting the incoming water temperature. The hot water supply passage 36 is provided with a can body temperature sensor 41 for detecting the temperature of the can body immediately after being heated by the heat exchanger 34 at a position upstream of the joining position with the downstream end of the bypass passage 37. A flow control valve 42 with a fully-closed switching function that adjusts the discharged hot water flow rate at a position downstream of the joining position and a discharged hot water temperature sensor 43 that detects the actual hot water temperature are provided. The bypass passage 37 is provided with a bypass flow rate control valve 44 for mixing the water from the incoming water passage 35 with the hot water of the hot water supply passage 36 at a predetermined mixing ratio. Of the flow rate control valve 42 and the bypass flow rate control valve 44, at least the flow rate control valve 42 has a fully-closed switching function that can be closed to a fully closed state in which the valve opening amount is zero based on a control signal from the child system controller SC1 or SC2. If it is in the fully closed switching state, the incoming water from the incoming water passage 51 is blocked. As a result, the use / nonuse of hot water supply by the number control or the like is performed depending on whether the flow rate control valve 42 is in the normal flow rate adjustment function operating state or in the fully closed switching state by the fully closed switching function. It is no longer necessary to install a dedicated electromagnetic on-off valve separately in the route.

  And as the hot water supply operation control by the individual controller 31 provided in each hot water heater 3, the incoming water flow rate from the incoming water passage 51 to the incoming water channel 35 by the hot water supply request (circulation heating request based on the operation of the circulation pump 53 or 54) is as follows. If it is detected by the incoming water flow rate sensor 39 that the minimum operating flow rate (MOQ) has been reached, the fuel gas supply system (not shown) to the combustion burner 38 and a combustion system 45 such as a blower fan (not shown) are shown. 3), the combustion burner 38 is combusted with a predetermined combustion amount so that the temperature of the hot water discharged into the hot water passage 52 becomes the set hot water temperature. In addition, when each individual controller 31 is communicatively connected to the child system controller SC1 or SC2, either the combustion control (use hot water supply) or the combustion prohibition (use no hot water supply) from the number control unit 91 described later. In response to the control signal, the corresponding control is executed. That is, when the combustion prohibition command is received, even if the flow control valve 42 is switched to the fully closed state based on the full-close switching command received together with the combustion prohibition command and a flow occurs in the water-inflow path 51, the flow does not enter the water-inflow path 35. On the other hand, when the combustion permission command is received, the flow control valve 42 is opened based on the opening switching command received together with the combustion permission command so that the water can enter the water inlet 35 from the water inlet 51. ing.

  Two circulating pumps 53, 54 are interposed in parallel in the hot water path 52, and when one of them is operated, the hot water stored in the hot water storage tank 6 passes through the circulation circuit constituted by the incoming water path 51 and the outgoing hot water path 52. It is circulated between the hot water supply system 2 and circulated and heated. Both circulation pumps 53 and 54 are provided with pump control units 55 and 56, respectively, so that operation control of the circulation pumps 53 and 54 is performed by an operation or stop control signal output to the pump control units 55 and 56. It has become. Each of the pump control units 55 and 56 is connected to the parent system controller PSC, and is operated by a control signal output from the parent system controller PSC. In particular, the first pump control unit 55 includes both the parent system controller PSC and both of them. The child system controllers SC1 and SC2 are also connected, and the first circulation pump 53 can be controlled by a control signal output from each child system controller SC1 or SC2 (see also FIG. 3).

  The hot water storage tank 6 is provided with a thermostat 61 for temperature management by hot water storage control. Upon receiving a contact signal output from the thermostat 61, the pump control unit 80 (see FIG. 3) of the parent system controller PSC controls the pump. Control signals are output to the units 55 and 56. That is, a contact signal is output to the parent system controller PSC when the hot water storage temperature in the hot water storage tank 6 is lowered to a set lower limit temperature (for example, 60 ° C.), whereby a circulation pump is supplied to any pump control unit 55 or 56. A control signal for operating 53 or 54 is transmitted. Circulation heating is started by the pump operation, and when the hot water storage temperature in the hot water storage tank 6 rises to a set upper limit temperature (for example, 65 ° C.), a corresponding contact signal is output from the thermostat 61 to the parent system controller PSC. A control signal for stopping the circulating pump 53 or 54 is sent to the corresponding pump control unit 55 or 56 to stop the circulation heating.

  In the pump controller 80 of the parent system controller PSC, the two circulation pumps 53 and 54 are alternately switched. In addition to improving the durability of the circulation pumps 53 and 54, even if one of the circulation pumps 53 or 54 breaks down, the other circulation pump 54 or 53 can continue the circulation heating so that the system is down. It is also for avoidance. In the case of 60 ° C. to 65 ° C. exemplified as the set lower limit temperature to the set upper limit temperature, a temperature (for example, 75 ° C.) higher than the set upper limit temperature is given to the remote controller RC so that hot water is quickly stored by circulating heating. Thus, the combustion operation of each water heater 3 is performed with the set hot water temperature of 75 ° C. as a target. Note that hot water supply from the hot water storage tank 6 to the hot water tap 62 is performed through the immediate hot water circuit 63. When the hot water tap 62 is opened by controlling the circulation pump 64 by, for example, the parent system controller PSC, the predetermined time is immediately obtained. High temperature hot water is made to come out.

  The parent system controller PSC (see FIG. 1) and the child system controllers SC1 and SC2 that receive overall control by the parent system controller PSC are built in the control box 7. The control box 7 also includes a power supply board 77, which receives power from an external power supply and performs predetermined voltage conversion to supply power to the parent system controller PSC and the child system controllers SC1, SC2. ing.

  As shown in FIG. 3, the parent system controller PSC has an overall control unit 81 for setting the remote controller set temperature set in the remote controller RC as a set hot water temperature for each child system controller SC1 or SC2, and a communication line 71 or The communication interruption detection unit 82 that determines whether or not communication with each of the child system controllers SC1 or SC2 via 72 is interrupted and detects the occurrence of the communication interruption, and any one of the child systems by the communication interruption detection unit 82 When the occurrence of communication interruption with the controller SC1 or SC2 is detected, the switching operation of the two circulation pumps 53, 54 by the pump control unit 80 is limited to the operation of the first circulation pump 53, and the operation is continued. And an emergency operation control unit 83 that executes control related to emergency operation of switching. In addition to the mutual communication via the communication line 71 or 72, it is of course possible to perform wireless mutual communication. The overall control unit 81 selectively sets one unit hot water supply system 2 to be operated for hot water supply first, in addition to the transmission of information related to the set hot water temperature, and sets the setting signal as a target of the one unit hot water supply system 2. A setting signal is sent to the system controller SC1 or SC2 and a setting signal related to the role setting for hot water supply operation is added to the child system controller SC2 or SC1 of the other unit hot water supply system 2 when the required hot water supply amount is insufficient. It has become.

  Each child system controller SC1 or SC2 determines whether or not communication with the number control unit 91 and the parent system controller PSC has been interrupted and detects the occurrence of communication disruption, and a communication disruption detection unit 92. And an emergency operation control unit 93 that generates a control signal for emergency operation and sends it to the unit control unit 91 when the occurrence of communication interruption is detected. The parent system controller PSC and each of the child system controllers SC1 and SC2 are constituted by a microcomputer having a CPU, a ROM, a RAM, and the like, and the pump control unit 80, the overall control unit 81, and a communication interruption detection unit. 82, the emergency operation control unit 83, the number control unit 91, the communication interruption detection unit 92, the emergency operation control unit 93, etc. are all installed by the software installed and installed in the ROM in advance to realize these functions. It is configured. This also applies to the system controller SC and the like in the second embodiment described later.

  The number controller 91 of each child system controller SC1 or SC2 controls the number of units if the unit hot water supply system 2 to which it belongs can be operated for hot water supply or can be operated based on the setting signal from the parent system controller PSC. It is supposed to start. The number control by the number control unit 91 is configured as follows. That is, any two hot water heaters (for example, 3a and 3b) selected from all the hot water heaters 3a, 3b,... Constituting the unit hot water system 2 to which the child system controller SC1 or SC2 belongs are selected. , Or 3g and 3h) are sub-combusted to satisfy the hot water supply request (circulation heating request) with the other main water heaters 3c, 3d,..., Or 3i, 3j,. A role is assigned to each of the water heaters, and when waiting for hot water supply, a combustion permission command is sent only to the main water heaters 3a, 3b, or 3g, 3h, and the other sub water heaters 3c, 3d, ..., or 3i, 3j, ... Is sent a combustion prohibition command. That is, at the time of standby for hot water supply, the main water heaters 3a and 3b, or 3g, 3h are connected to the incoming water passage 51 and the outgoing hot water route 52, and the other sub hot water heaters 3c, 3d,. In this case, the water inlet path 51 and the hot water outlet path 52 are blocked (impossible to pass water).

  And, for example, when the hot water tap at the downstream end is opened and water enters the water inlet passage 51 and the incoming water flow rate to the main water heaters 3a, 3b or 3g, 3h becomes equal to or higher than the MOQ, the main water heaters 3a, 3b, Alternatively, when the combustion of 3g, 3h is started and the hot water supply operation control is started, and the hot water supply capacity of the main water heaters 3a, 3b or 3g, 3h is insufficient with respect to the required hot water supply amount, A supplement request is output from 3b, 3g, or 3h to the child system controller SC1 or SC2, and the child system controller SC1 or SC2 that receives the request gives combustion permission to any one of the sub water heaters (eg, 3c or 3i). A command will be sent. As a result, the flow rate control valve 42 of the sub water heater 3c or 3i is switched open, and the sub water heater 3c or 3i is also the main water heater 3a, 3b, or 3g, 3h when the incoming water flow rate sensor 39 detects the incoming water flow rate above the MOQ. It is burned with. Furthermore, if the required hot water supply amount is insufficient by the combustion of the three water heaters 3a, 3b, 3c, or 3g, 3h, 3i, the other sub-water heaters 3d, 3j, etc. are also burned. This will increase the number of combustion. Similarly, when the demand for hot water supply is reduced, the number of combustion is sequentially reduced by sending out the combustion prohibition commands in order accordingly. As described above, at the start of the hot water supply operation when a hot water supply request is generated, the two hot water heaters 3 and 3 selected and set from all the unit hot water systems 2 and 2 are operated for combustion. The assignment of the role of the main water heater is switched every time a predetermined time elapses or is switched according to the accumulated combustion time for each water heater.

  The above is a case where each element of the hot water supply system is operating normally. In this case, the determination that the mutual communication between the parent system controller PSC and each of the child system controllers SC1 and SC2 is normal is as follows. It is done like this. That is, the communication interruption detection unit 82 of the parent system controller PSC individually sends inquiry signals to the communication interruption detection units 92 and 92 of each child system controller SC1 or SC2 every predetermined time (for example, 2.5 sec), Upon receiving this inquiry signal, the communication interruption detection units 92, 92 of the child system controller SC1 or SC2 send confirmation signals from the communication interruption detection units 92 to the communication interruption detection unit 82 of the parent system controller PSC. . Then, the communication interruption detection unit 82 of the parent system controller PSC determines that the communication connection with the child system controller SC1 or SC2 is normal by receiving the confirmation signal, while the communication interruption detection unit of each child system controller SC1 or SC2 In 92 and 92, the inquiry signal is received to determine that the communication connection with the parent system controller PSC is normal.

  On the other hand, determination / detection that a communication interruption has occurred is performed as follows. That is, if the communication interruption detection unit 92, 92 of each child system controller SC1 or SC2 does not receive the inquiry signal for a predetermined determination time (for example, 150 sec = 2.5 min), the communication with the parent system controller PSC. In the meantime, it is determined that a communication interruption has occurred, and a communication interruption detection signal is output to the emergency operation control unit 93, while the communication interruption detection unit 82 of the parent system controller PSC does not receive the above confirmation signal. If it continues for the determination time (for example, 150 sec = 2.5 min), it is determined that communication interruption has occurred with the child system controller SC1 or SC2, and a detection signal indicating the occurrence of communication interruption is output to the emergency operation control unit 83. It has become. As a cause of such communication interruption, disconnection of the communication line 71 or 72, occurrence of a failure such as a substrate failure of the parent system controller PSC, and the like are assumed. If the communication line 71 or 72 is disconnected, the parent system controller PSC itself functions normally, but communication to one of the two child system controllers SC1 and SC2 becomes impossible. If the parent system controller PSC is faulty, communication to both of the two child system controllers SC1 and SC2 becomes impossible.

  Then, when the communication interruption is detected, the emergency operation control units 93 and 83 execute processing as follows. In each emergency operation controller 93 of the child system controllers SC1 and SC2, first, as shown in FIG. 4, the child system controller SC1 or SC2 is connected to the parent system controller PSC in order to confirm its own role recognition. It is confirmed whether or not there is connection information (step SA1). If there is no connection information indicating that the communication connection is established, the emergency operation is originally unnecessary, so that the original number control is continued without performing any processing (NO in step SA1), while the connection information indicating that the communication connection is established. If registered (YES in step SA1), it is determined whether or not a communication interruption with the parent system controller PSC has occurred based on the presence or absence of a detection signal from the communication interruption detection unit 92 (step SA2). If there is no communication interruption, no processing is performed and the original number control in the normal state is continued (NO in step SA2), but if communication interruption occurs (YES in step SA2), a thermostat is further installed. The presence or absence of information is confirmed (step SA3).

  Before confirming the occurrence of this communication disruption and executing the subsequent steps SA3 to SA6 (especially the pump operation of step SA5), the communication disruption detection unit 82 of the parent system controller PSC described later The delay process may be executed in consideration of a timing deviation from the occurrence detection. As the delay time, a multiple (for example, 10 sec) of a cycle (for example, 2.5 sec) for sending the inquiry signal may be set. The reason for executing the delay process is that if the detection of the occurrence of communication interruption in the parent system controller PSC shifts to a side slower than the detection of the occurrence of communication interruption on the child system controllers SC1 and SC2, the pump control of the parent system controller PSC is performed. During the operation of the second circulation pump 54 by the pump operation control by the unit 80, the first circulation pump 53 described later is operated (see step SA5), and the power supply capacity of simultaneous operation of the two circulation pumps 53 and 54 is increased. This is to prevent a burden from occurring. That is, after waiting for switching of the pump operation control described later based on the occurrence detection in the communication interruption detection unit 82 of the parent system controller PSC, the operation of the first circulation pump 53 on the side of the child system controllers SC1 and SC2 is performed. This is to get you started.

  If the thermostat installation information is registered (YES in step SA3), the controller 31 instructs the individual controller 31 after changing the set hot water temperature Ts (step SA4). That is, as the set hot water temperature Ts, a subtracted temperature value obtained by subtracting a predetermined set temperature X ° C. (for example, X = 10 ° C.) from the remote control set temperature last received and stored before the communication interruption is set. Alternatively, an upper limit temperature value stored and set in advance is set. However, the upper limit temperature value is applied only when the upper limit temperature value is lower than the remote control set temperature received and stored at the end. For example, if the remote control set temperature is 75 ° C., it is set to 65 ° C. (= 75 ° C.−10 ° C.), or the upper limit temperature value is set in advance as a temperature value lower than the normal set lower limit temperature 60 ° C. The temperature is not higher than ° C. At this time, if the remote control set temperature received last before the interruption of communication is, for example, 55 ° C., the remote control set temperature of 55 ° C. is set as the set hot water temperature Ts as it is. And while operating the 1st circulation pump 53 and continuing the operation | movement, the combustion operation | movement of each water heater 3 is also continued (step SA5). The subtracted temperature value or the upper limit temperature value is stored in advance and constitutes a limit temperature that limits the temperature to a predetermined temperature or less.

  On the other hand, if the thermostat installation information is not registered (NO in step SA3), a command is issued to each individual controller 31 using the remote control set temperature acquired last before the communication interruption as the set hot water temperature Ts (step SA6). That is, if the remote control set temperature acquired last is, for example, 75 ° C., Ts = 75 ° C., 65 ° C., Ts = 65 ° C., and 55 ° C., Ts = 55 ° C. Then, the operation and the operation continuation of the first circulation pump 53 and the combustion operation continuation (step SA5) of each water heater 3 are executed.

  On the other hand, in the emergency operation control unit 83 of the parent system controller PSC, as shown in FIG. 5, whether or not the communication interruption with the child system controllers SC1 and SC2 has occurred is determined by the presence or absence of the detection signal from the communication interruption detection unit 82. Based on the determination (step SB1). If neither of the child system controllers SC1 and SC2 has a communication interruption, the original overall control in the normal state is continued without performing any processing (NO in step SB1), while one of the child system controllers SC1 or SC2 If communication interruption has occurred in SC2 (YES in step SB1), the following processing is performed in order to match the emergency operation control on the side of the child system controllers SC1 and SC2. That is, the contents of the pump operation control by the pump control unit 80 (alternate switching operation of the two circulation pumps 53 and 54) are switched to the operation of only the first circulation pump 53 and the operation continuation (step SB2). At the same time, when the communication interruption occurs only in one of the child system controllers SC1 or SC2, the other child system controller SC2 or SC1 in which no communication interruption has occurred, Along with information indicating that communication interruption has occurred in the system controller SC1, a command is issued so as to execute emergency operation control (see FIG. 4) by the emergency operation control unit 93 thereafter. If communication interruption occurs in any one of the child system controllers SC1 or SC2 (in the case of YES at step SB1), the content of the pump operation control by the pump control unit 80 is switched to the control content of step SB2 as described above. This process is not essential. That is, in this case, since the parent system controller PSC itself is functioning normally, the original pump control is continued by the pump control unit 80 of the parent system controller PSC, and the communication is interrupted by the child system controller SC1 or SC2 on the communication interruption side. What is necessary is to give priority to the pump control by the parent system controller PSC over the pump control based on the emergency operation.

  According to the above, for example, even if a communication interruption due to a failure of the parent system controller PSC or a communication interruption of only one of the child system controllers SC1 and SC2, an emergency operation is performed. As described above, after switching to the set hot water temperature selected based on the presence or absence of the thermostat installation information (see step SA4 or SA6), the circulating heating of the hot water storage tank 6 can be continued. Such an emergency operation makes it possible to prevent the hot water in the hot water storage tank 6 that is the hot water supply destination of each hot water heater 3 from being excessively hot. That is, when the thermostat 61 is installed and in a normal state, the circulation pumps 53 and 54 are turned ON / OFF by the parent system controller PSC based on the contact signal from the thermostat 61, and the hot water storage temperature management range (60 ° C. to 65 ° C.) by the thermostat 61 is set. The hot water storage can be quickly formed by the combustion operation with the remote control set temperature (75 ° C.) that is considerably higher than (° C.) as the set hot water temperature. On the other hand, if the communication interruption occurs, the set hot water temperature is changed to a temperature value lower than the lower limit temperature of the hot water storage temperature management range based on the installation information of the thermostat 61, and the combustion operation is performed. Even if it is made, it can avoid that the hot water storage temperature in the hot water storage tank 6 falls into an excessively high temperature state.

<Second Embodiment>
FIG. 6 shows a hot water supply system according to the second embodiment. This 2nd Embodiment is comprised using the system controller SC as a high-order control part or a central control part, and the individual controller 30 incorporated in each water heater 3 as a low-order control part or a separate control part, respectively. The system controller SC in the second embodiment corresponds to the child system controller SC1 in the first embodiment, and this system controller SC is built in the hot water heater 3a together with the original individual controller 30. That is, the hot water supply system is configured by using only one unit hot water supply system 2 of the first embodiment. The upper and lower levels of the parent system controller PSC of the first embodiment and the two or more child system controllers SC1 and SC2 are used. Instead of the hierarchical structure, a system controller SC and two or more individual controllers 30, 30,...

  That is, the system controller SC has the same control configuration as the parent system controller PSC of the first embodiment, and each individual controller 30 has the same control configuration as the child system controllers SC1 and SC2 of the first embodiment.

  Accordingly, by controlling the operation of the two pump control units 55 and 56 by the control signal from the system controller SC based on the contact signal from the thermostat 61, the ON / OFF operation control is performed while alternately switching the two circulation pumps 53 and 54. It is supposed to be. Accordingly, the hot water in the hot water storage tank 6 is circulated and heated in the same manner as in the first embodiment, and the hot water storage temperature is maintained within a predetermined hot water storage temperature management range (60 ° C. to 65 ° C.). In addition, the remote controller set temperature input and set to the remote controller RC is output to the system controller SC, and a command is issued from the system controller SC to each individual controller 30 using the remote controller set temperature as the set hot water temperature.

  If the communication with the individual controllers 30, 30,... Due to the failure of the system controller SC or the communication with any of the individual controllers 30 due to the disconnection of the communication line, etc. occurs, each individual controller 30. The emergency operation control based on the detection of the occurrence of communication interruption on the side of the system controller is performed in the same manner as that of the child system controllers SC1 and SC2 of the first embodiment (see FIG. 4), or the occurrence of communication interruption on the system controller SC side The emergency operation control based on the detection is performed in the same manner as that of the parent system controller PSC of the first embodiment (see FIG. 5).

  Also in the second embodiment described above, whether the communication interruption due to the failure of the system controller SC or the communication interruption with any of the individual controllers 30 is the same as in the first embodiment. In addition, as an emergency operation, it is possible to continue the circulating heating of the hot water storage tank 6 after switching to the set hot water temperature selected based on the presence or absence of the thermostat installation information. It becomes possible to avoid the hot water in the hot water storage tank 6 that is the hot water supply destination of each hot water heater 3 from being excessively hot due to such an emergency operation as in the first embodiment.

<Other embodiments>
The present invention is not limited to the above-described embodiments, but includes other various embodiments. That is, in the first embodiment, the unit hot water supply system 2 is configured by controlling the number of the six hot water heaters 3, 3,... By one child system controller SC1 or SC2, and the unit hot water supply system 2 is set in two sets. Although an example in which the parent system controller PSC is connected and integratedly controlled is shown, the present invention is not limited to this, and the number of water heaters 3 constituting the unit hot water system 2 may be an arbitrary number of two or more. The number of unit hot water supply systems 2 (the number of sets) may be an arbitrary number of 3 or more (for example, 4 sets), and the number of target child system controllers to be controlled by the parent system controller PSC may be the same as the number of unit hot water systems. it can.

3 Hot water heater 6 Hot water storage tank 30 Individual controller (lower control unit, individual control unit)
51 Inlet path 52 Outlet path 53, 54 Circulation pump 61 Thermostat 91 Number control unit 92 Communication disruption control unit 93 Emergency operation control unit PSC Parent system controller (upper control unit, upper central control unit)
SC1, SC2 Child system controller (lower control unit, lower central control unit)
SC system controller (upper control unit, central control unit)
RC remote control

Claims (4)

A hot water supply system comprising a plurality of water heaters interposed in parallel between a water inlet path and a hot water outlet path, and a control unit that controls the plurality of water heaters,
A high-order control unit that receives and obtains an output of a remote control set temperature set in the remote control from a remote control, and a low-level control unit that obtains system setting information related to the set hot water temperature and system configuration based on the remote control set temperature from the high-order control unit by communication And
Each of the lower-level control units detects a communication interruption between the upper-level control unit and a communication interruption detection unit that detects that communication with the upper-level control unit has been interrupted. An emergency operation control unit that controls emergency operation independently of the host control unit,
The emergency operation control unit selects, based on the system configuration information, a set hot water temperature acquired last from the host control unit or a limit temperature that is stored in advance and is limited to a predetermined temperature or less. It is configured to perform hot water supply control by each hot water heater as a set hot water temperature in emergency operation.
A hot water supply system characterized by that. The hot water supply system according to claim 1,
A circulation pump, a hot water storage tank, and a thermostat that outputs a contact signal to the host controller based on the hot water storage temperature in the hot water storage tank, and the operation of the circulation pump causes hot water in the hot water storage tank to flow into the water inlet path. Introduced as incoming water, and is configured to be circulated and heated to be returned to the hot water storage tank through the hot water path after being heated by the water heater,
The system configuration information is thermostat installation information related to the presence or absence of the thermostat installation,
The emergency operation control unit is configured to select the limit temperature and switch the set hot water temperature when the system configuration information indicates that a thermostat is installed. The hot water supply system according to claim 1 or 2,
The lower control unit is a lower central control unit that controls the number of units that are communicably connected to the plurality of water heaters and burn the target water heaters.
The upper controller is a hot water supply system that is an upper central controller that is individually connected to the lower central controller and performs overall control of the lower controller. The hot water supply system according to claim 1 or 2,
The upper control unit is a central control unit that is connected to the plurality of water heaters and performs operation control on the plurality of water heaters,
The subordinate control unit is a hot water supply system that is an individual control unit that is provided in each of the water heaters and individually controls each water heater.

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