JP2012047422A - Hot water storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water storage system that prevents system down due to emergency treatment, even when a failure occurs relating to detection of a temperature of hot water in a hot water storage tank.SOLUTION: When a heating request signal has not been output from a thermostat of the hot water storage tank for a predetermined determination time (SA1), forced circulation is implemented by actuating only a circulation pump, while prohibiting combustion of a water heater (SA2). When a value Th detected by a water inlet temperature sensor of the water heater is lower than a determination temperature Tj (YES in SA3), occurrence of a failure in the thermostat is determined, and the failure is reported (SA6). Combustion is started (SA7), and stopped after heating up to a pump stop temperature Tjf (SA8, SA9).

Description

  The present invention stores hot water heated by a water heater in a hot water tank and supplies hot water from the hot water tank to a hot water supply destination, and circulates by a hot water heater by operating and stopping a circulation pump based on the temperature of the hot water in the hot water tank. For hot water storage systems that can be heated, especially in the hot water tank by emergency operation even when temperature detection is not possible due to malfunction of equipment related to temperature detection in the hot water tank or disconnection of the communication line. The present invention relates to a control technology that can heat hot water.

  Conventionally, a hot water storage system has been known in which two or more hot water heaters and a hot water tank are connected by a circulation path, and hot water in the hot water tank is introduced into the hot water heater by the operation of a circulation pump to enable circulation heating. (For example, refer to Patent Documents 1 and 2). In this apparatus, the temperature of the hot water in the hot water storage tank is detected by a temperature sensor, and if the temperature is lower than a predetermined value, circulation heating is performed, and if the temperature rises to a predetermined value, the circulation heating is stopped.

Japanese Patent No. 2532319 JP-A-6-137679

  By the way, by adopting a hierarchical control system, the scale of the connected hot water storage 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, hot water in a hot water tank is introduced into a water inlet path in which a large number of water heaters are connected in parallel by the operation of a circulation pump, and after being heated by the water heater, it is returned to the hot water tank through a hot water outlet path. This is realized by the execution of the circulation operation. However, in the emergency operation, how to operate the circulation pump 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 heater. When the temperature reaches (° C.), the operation control of stopping the operation of the circulation pump is performed. On the other hand, the operation control of the circulation pump is performed by the upper control unit, and the number of connected hot water heaters is controlled. It has been considered to link with the lower control unit through communication.

  However, in the hot water storage system as described above, for example, when a temperature sensor installed in the hot water tank breaks down or an abnormality such as a disconnection of the communication line for output from the temperature sensor to the controller occurs, Since the temperature information of the hot water is not obtained, the circulation heating operation of maintaining the inside of the hot water tank at a constant temperature based on the operation control of the operation / stop of the circulation pump becomes impossible. If this happens, the operation control of the circulation pump becomes impossible, or the linkage with the water heater by the operation of the circulation pump becomes impossible, so that the original purpose of the hot water storage system cannot be realized (system down state). It will fall.

  In particular, a thermostat is installed in the hot water tank, and the circulation pump is automatically activated and stopped based on the signal output from the thermostat, while the water heater side is independently controlled by the controller. In such a case, if an abnormality such as a malfunction of the thermostat or disconnection of the output line occurs, the operation of the circulation pump itself becomes impossible and the operation is stopped, and the system immediately falls down. In addition to facilitating the discovery of the system down, it takes time to recover from the system down.

  The present invention has been made in view of such circumstances, and the purpose of the present invention is to provide a system down state by emergency processing even when an abnormality relating to temperature detection of hot water in the hot water tank has occurred. The object is to provide a hot water storage system that can avoid the possibility of falling into water.

  In order to achieve the above object, the present invention comprises a hot water storage tank provided with temperature detection means, a hot water heater, and a circulation means for circulating hot water in the hot water storage tank through the hot water heater. Based on the output of the detection means, the circulation means is operated and the hot water storage system configured to perform the heating operation by the water heater is provided with the following specific items. That is, forced circulation is started by the circulation means when the output of the temperature detection means maintains the state corresponding to the necessity of the heating operation despite the elapse of a predetermined determination time while the heating operation is stopped. Then, emergency operation control means for performing emergency operation processing based on the output of the temperature sensor provided in the water heater is provided (claim 1).

  In the case of the present invention, the temperature detecting means of the hot water tank is maintained if the output of the temperature detecting means maintains the state corresponding to the necessity of the heating operation despite the fact that the predetermined determination time has passed while the heating operation is stopped. The emergency operation process is executed by the emergency operation control means when it is determined that an abnormality such as a malfunction or disconnection of the detection output line has occurred. As a result, it is possible to avoid the possibility of falling into a system-down state due to leaving the abnormality with an abnormality such as a failure of the temperature detecting means.

  In the hot water storage system of the present invention, the emergency operation process may include an abnormality notification process by a notification means (Claim 2). By doing in this way, it becomes possible to make a user grasp quickly that abnormality concerning temperature detection has occurred, and it becomes possible to take subsequent measures at an early stage. Thereby, it can avoid at an early stage that it reaches a system down state, without heating to a hot water tank.

  The emergency operation process may include a heating process in which the hot water heater is combusted based on the output of the temperature sensor to maintain the hot water in the hot water storage tank within a predetermined temperature range (Claim 3). By doing in this way, even if abnormality relating to the temperature detection means such as failure of the temperature detection means occurs, the hot water heater is combusted based on the output of the temperature sensor provided in the hot water heater, so that The heat treatment can be performed so that the temperature of the hot water is maintained within a predetermined temperature range.

  In such heat treatment, the emergency operation control means may be provided with a temperature value stored in advance as a threshold value for the output of the temperature sensor for the heat treatment (claim 4). By doing in this way, the maintenance to the predetermined temperature range based on the said heat processing can be performed easily.

  Alternatively, as the emergency operation control means, the threshold value for the output of the temperature sensor is acquired from the temperature sensor provided in the water heater during normal heating operation based on the output of the temperature detection means for the heating process. An acquisition processing unit may be provided (claim 5). By doing in this way, the maintenance to the predetermined temperature range based on the heat treatment can be performed accurately as in the case based on the original temperature detection means.

  Further, as the emergency operation control means, when the forced circulation is executed, the heat treatment by the water heater is prohibited, and an abnormality relating to the temperature detection means occurs based on the output of the temperature sensor provided in the water heater. It can be set as the structure determined about whether it exists (Claim 6). By doing so, it is possible to comprehend the temperature of the hot water tank in practice by forcibly circulating in a non-heated state and checking the temperature with the temperature sensor of the water heater. Thus, it is possible to more accurately determine whether or not an abnormality relating to the above has occurred.

  Further, the water heater in the above hot water storage system is a plurality of water heaters connected in parallel to the circulation path from the hot water tank, and the emergency operation control means communicates with both the temperature detection means and the water heater. It can be included in a connected central control unit (claim 7). By doing in this way, in the hot water storage system which consists of a connection type hot water heater and a hot water storage tank, the effect | action by the above-mentioned each claim is acquired.

  As described above, according to the hot water storage system of the present invention, the state in which the output of the temperature detection means corresponds to the necessity of the heating operation, even though the predetermined determination time has passed with the heating operation stopped. If it is maintained, it can be determined that an abnormality such as a failure of the temperature detection means of the hot water tank or disconnection of the detection output line has occurred, and the emergency operation control means can execute the emergency operation processing. As a result, it is possible to avoid the possibility of falling into a system-down state due to leaving the abnormality with the abnormality of the temperature detecting means occurring.

  In particular, according to claim 2, by performing the abnormality notification process by the notification means as the emergency operation process, the user can be quickly ascertained that an abnormality relating to temperature detection has occurred. Can be taken early. Thereby, it can avoid at an early stage that it reaches a system down state, without heating to a hot water tank.

  According to a third aspect of the present invention, the emergency detection process includes a heating process in which a hot water heater is combusted to maintain hot water in the hot water tank in a predetermined temperature range, thereby detecting a temperature such as a failure of the temperature detection means. Even if an abnormality related to the means occurs, the hot water heater can be burned based on the output of the temperature sensor provided in the hot water heater, so that the temperature of the hot water in the hot water tank is maintained within a predetermined temperature range. It becomes possible to perform the heat treatment.

  According to the fourth aspect of the present invention, a temperature value stored in advance as a threshold value for the output of the temperature sensor for the heat treatment is provided, so that it is easily maintained within a predetermined temperature range based on the heat treatment. Will be able to.

  According to the fifth aspect, for the heat treatment, an acquisition processing unit is provided for acquiring a threshold value for the output of the temperature sensor from the temperature sensor provided in the water heater during normal heating operation based on the output of the temperature detection means. By doing so, it becomes possible to accurately maintain the temperature within a predetermined temperature range based on the heat treatment as in the case based on the original temperature detection means.

  According to the sixth aspect, the temperature of the hot water storage tank is actually grasped by checking the temperature with the temperature sensor of the hot water heater in a state where the hot water heater is in an unheated state and the circulation means is forcedly circulated. This makes it possible to more accurately determine whether or not an abnormality relating to the temperature detection means has occurred.

  Furthermore, according to the seventh aspect, in the hot water storage system including the connected hot water heater and the hot water storage tank, it is possible to obtain the functions and effects of the above respective claims.

It is a mimetic diagram showing an embodiment of a hot water storage system of the present invention. It is a schematic diagram which shows the structural example of each water heater applied to the hot water storage system of FIG. It is a control block diagram of the hot water storage system of FIG. It is a flowchart which concerns on emergency operation control in the hot water storage system of FIG. 5 (a) is a partial corresponding view of FIG. 1 showing another embodiment different from FIG. 1, and FIG. 5 (b) is a hot water storage according to another embodiment different from FIG. 1 and FIG. 5 (a). It is a schematic diagram which shows a system.

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

  FIG. 1 shows a hot water storage system according to an embodiment of the present invention. In this hot water storage system, two or more predetermined numbers (six are exemplified in the figure) of hot water heaters 3, 3,... Controlled by a system controller SC as a central control unit are connected to a water inlet path 51 and a hot water outlet path. 52 connected in parallel. In the example of the figure, the six water heaters 3, 3,... Are also attached in order with a reference numeral 3a, 3b,. Then, 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 introduced into the water inlet path 51 from below by the operation of the circulation pump 53 and / or 54 interposed in the circulation path. The hot water in the hot water tank 6 is circulated and heated by sending it to the hot water heaters 3, 3,... And heating it in the hot water heaters 3, 3,. Yes.

  Each water heater 3 has its water inlet 32 connected to the water inlet path 51, while each outlet 33 is connected to the hot water path 52, and is connected between the water inlet path 51 and the hot water path 52 in parallel. It is disguised. Each of the water heaters 3 is subjected to hot water operation control mainly based on the operation control of the combustion system by an individual controller 30 incorporated in each water heater 3, and the individual controller 30 of each of the water heaters 3 is connected to the system controller SC in communication. Each individual controller 30 is adapted to receive control signals from the system controller SC mainly relating to operation settings in the unit control and setting of the set hot water temperature. The system controller SC outputs a control signal from a thermostat 61 described later as information relating to hot water storage control of the hot water tank 6, and a command signal related to a remote control set temperature input and set to the remote controller RC also serving as a notification means. It is like that. The system controller SC stores such information in a non-volatile memory (EEPROM) so that the stored information is not lost when the system controller SC is restarted after the power is turned off.

  The system controller SC and the individual controllers 30, 30,... Of each hot water heater 3 are individually connected to each other via a communication connection line 71 so that bidirectional communication can be performed. Recognizing the number of connected water heaters 3, 3,... Constituting the system (six in the illustrated example) and specifying each of the water heaters 3a, 3b,... Recognizing that the operation is controlled based on a control command from the system controller SC instead of a single installation type, it is stored in, for example, a nonvolatile memory. Further, the individual controllers 30, 30,... Receive the remote controller set temperature output as the set hot water temperature from the system controller SC, and execute the combustion operation control based on the remote controller set temperature. Further, each of the individual controllers 30, 30,... Includes a power supply board, and receives a power supply current from a power supply line 72 that supplies power to each water heater 3 through the power supply board.

  FIG. 2 shows a gas water heater that burns gas as fuel as an example of the water heater 3. Note that the water heater 3 illustrated in FIG. 2 heats the incoming water from the water inlet 32 by combustion heat and the like, and discharges the heated hot water from the outlet 33, and has such a function. If so, the hot water storage system 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 (for example, 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 34. 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 system controller SC. 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.

  As the hot water supply operation control by the individual controller 30 provided in each hot water heater 3, the incoming water flow rate from the incoming water passage 51 to the incoming water passage 35 is determined by a hot water supply request (circulation heating request based on the operation of the circulation pump 53 or 54). 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 30 is connected to the system controller SC in communication, the individual controller 30 receives a control signal for either combustion permission (use of hot water supply) or combustion prohibition (no use of hot water supply) from the number control unit 91 described later. In response, 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. It should be noted that the flow rate control valve 42 is not located at the position shown in FIG. 2 but at a position downstream of the can body temperature sensor 41 and upstream of the junction with the downstream end of the bypass passage 37. You may make it wear. In this case, when the combustion prohibition command is received, both the flow rate control valve 42 and the bypass flow rate control valve 44 are fully closed, and when the combustion permission command is received, the flow rate control valve 42 is fully closed. Only the bypass flow rate control valve 44 may be switched to the open state while maintaining the flow rate, and the flow rate control valve 42 may be switched to the open state after detecting water flow.

  Two circulating pumps 53 and 54 are interposed in parallel in the hot water path 52 as circulation means, and one of them is operated to store the hot water in the hot water storage tank 6 by the incoming water path 51 and the outgoing hot water path 52. It is circulated between the hot water heaters 3, 3,. 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 system controller SC and is operated by a control signal output from the system controller SC. (See also Figure 3).

  The hot water storage tank 6 is provided with a thermostat 61 as temperature detecting means for temperature management by hot water storage control. Upon receiving a contact signal output from the thermostat 61, a pump controller 90 (see FIG. 3) of the system controller SC. Control signals are output to the pump control units 55 and 56. That is, when the hot water storage temperature in the hot water storage tank 6 is lowered to the set lower limit temperature (for example, 60 ° C.), the contact is short-circuited and a contact signal is output to the system controller SC. In response to this, a control signal for operating the circulation pump 53 or 54 is sent. 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.), the contact of the thermostat 61 is opened correspondingly, and thereby the circulation that has been operated A control signal for stopping the pump 53 or 54 is sent to the corresponding pump control unit 55 or 56 to stop the circulation heating.

  In the pump controller 90 of the system controller SC, 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. Further, 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 operation of the circulation pump 64 by, for example, the system controller SC, the predetermined time is immediately obtained. Hot water is discharged. 1 shows only one hot water tap 62. However, the present invention is not limited to this. In addition to two or more hot water taps being connected to the immediate hot water circuit 63, there is not only one immediate hot water circuit 63. A plurality of things may be connected.

  Furthermore, even if the output of the control signal from the thermostat 61 is interrupted, the pump controller 90 of the system controller SC can perform emergency operation control, which will be described later, even if an abnormality such as failure of the thermostat 61 or communication interruption occurs. As described above, the switching operation of the two circulation pumps 53 and 54 and the control related to the operation of either one of the circulation pumps 53 or 54 can be executed.

  As shown in FIG. 3, the system controller SC includes a number control unit 91, an abnormality determination processing unit 92 that determines whether an abnormality relating to temperature detection of hot water in the hot water tank 6 from the thermostat 61 has occurred, There is provided an emergency operation control unit 93 that executes a heating process for maintaining the hot water in the hot water tank 6 in a predetermined temperature range by the emergency operation control when it is determined by the determination processing unit 92 that an abnormality has occurred. Furthermore, a pump operating temperature acquisition processing unit 94 and a pump stop temperature acquisition processing unit 95 that are used for executing the emergency operation control by the emergency operation control unit 93 are provided. The acquisition processing units 94 and 95 each include a thermostat. While the circulating heating by 61 is functioning normally, the pump operating temperature and the pump stop temperature are acquired. That is, although the contact signal itself is output from the thermostat 61 to the system controller SC, the set lower limit temperature (corresponding to the pump operating temperature) and the set upper limit temperature (corresponding to the pump stop temperature) set in the thermostat 61 are controlled. Since it is not output as information, the acquisition process is performed in advance in the normal state stage in order to execute the emergency operation control.

  The system controller SC is composed mainly of a microcomputer having a CPU, a ROM, a RAM and the like, and includes the pump control unit 90, the number control unit 91, the abnormality determination processing unit 92, the emergency operation control unit 93, and the acquisition processing unit. 94, 95, etc. are configured by software installed and installed in the ROM in advance to realize these functions, or by such software and electronic devices operated by the software. The abnormality determination processing unit 92, the emergency operation control unit 93, and the acquisition processing units 94 and 95 constitute emergency operation control means for performing an emergency operation process.

  The number control by the number control unit 91 is configured as follows. That is, other hot water heaters 3c, 3d are used as main hot water heaters for first burning any two hot water heaters (for example, 3a and 3b) selected from all the hot water heaters 3a, 3b,. ,... Are assigned to the sub-water heaters that are additionally combusted in order to satisfy the hot-water supply request (circulation heating request), and at the time of hot-water standby, a combustion permission command is first sent only to the main water heaters 3a and 3b, and the other sub-water heaters. A combustion inhibition command is sent to 3c, 3d,. That is, during the hot water supply standby, the incoming water passage 51 and the outgoing hot water route 52 are communicated only through the main hot water heaters 3a and 3b, and the other auxiliary hot water heaters 3c, 3d,. It is designed to keep the water out.

  Then, when the circulation pump 53 or 54 is operated to cause water entry based on the circulation flow in the water intake path 51 and the incoming water flow rate to the main water heaters 3a, 3b becomes equal to or higher than the MOQ, combustion of the main water heaters 3a, 3b is started. When the hot water supply operation control is started and the hot water supply capacity of the main hot water heaters 3a and 3b is insufficient with respect to the required hot water supply amount, a supplement request is output from the main hot water heaters 3a and 3b to the system controller SC. The system controller SC sends a combustion permission command to any one of the sub water heaters (for example, 3c). As a result, the flow control valve 42 of the sub water heater 3c is opened and switched, and the sub water heater 3c is burned together with the main water heaters 3a and 3b when the incoming water flow rate sensor 39 detects the incoming water flow rate equal to or higher than the MOQ. Further, if the required amount of hot water supply is insufficient due to the combustion of the three hot water heaters 3a, 3b, 3c, the number of combustion is increased so that the other sub water heaters 3d and the like are further combusted. 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. 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.

  As described above, in the acquisition processing unit 94 that performs acquisition processing of the pump operating temperature that is executed while each element of the hot water storage system is operating normally, first, the pump control unit 90 receives the contact signal from the thermostat 61. When the circulation pump 53 or 54 is operated and the combustion operation in the main water heater 3 is started, the main water heater that is in the combustion operation at a time point after a predetermined time has elapsed from the operation start of the circulation pump 53 or 54. 3 separately stores the detected incoming water temperature by the incoming water temperature sensor 40. That is, the temperature of the circulating flow at the start of one circulating heating operation is stored. And also at the start of the next circulating heating operation, the detected incoming water temperature at a predetermined time point is stored in the same manner as described above, and this is repeated for the set number of times, and the value obtained by averaging the detected incoming water temperature for the set number of times is obtained. Obtained as pump operating temperature. The point in time after the elapse of the predetermined time is that hot water near the installation position of the thermostat 61 in the hot water tank 6 reaches the incoming water temperature sensor 40 of the water heater 3 through the incoming water passage 51 after the operation of the circulation pump 53 or 54 starts. For example, 2 minutes may be set as the predetermined time.

  Further, in the pump stop temperature acquisition processing unit 95, after the circulation heating operation is started by the output of the contact signal from the thermostat 61, the contact of the thermostat 61 is opened and the pump control unit 90 opens the circulation pump 53 or 54. The detected incoming water temperature by the incoming water temperature sensor 40 of the main water heater 3 at the time when the operation is stopped is stored. That is, the temperature of the circulating flow at the time of stopping the circulating heating operation once is stored. And when the next circulating heating operation is stopped, the detected incoming water temperature is stored in the same manner as described above, and this is repeated for the set number of times, and the value obtained by averaging the detected incoming water temperatures for the set number of times set as the pump stop temperature. get. If the acquisition process is performed as described above, the hot water tank 6 is maintained in a predetermined temperature range in accordance with the lower limit set temperature and the upper limit set temperature of the thermostat 61 unknown to the system controller SC or using substantially the same threshold value. This makes it possible to accurately perform the heat treatment.

  Next, processing by the abnormality determination processing unit 92 and the emergency operation control unit 93 will be described with reference to the flowchart of FIG. First, it is determined whether or not the duration time during which the heating required signal is not output is longer than the determination time (step SA1). The heating required signal is a signal related to a heating request, that is, a contact signal output from the thermostat 61, and the duration of the state where the heating required signal is not output is the stop time of the previous circulating heating operation (contact of the thermostat 61). This is an elapsed time in which the timer is started from the time of switching to open) and the contact signal is continued without being output. Considering the internal capacity of the hot water tank 6 and the degree of heat release from the hot water tank 6, this elapsed time is the temperature of the hot water in the hot water tank 6, which was the set upper limit temperature at the time when the previous circulating heating operation was stopped. If it is longer than a determination time (for example, 60 minutes) that would naturally fall below the set lower limit temperature if the non-heating state is continued, it is determined that there is a possibility of occurrence of an abnormality and the following determination is made. Implement the process for

  That is, while allowing water to enter the hot water heaters 3 and 3 assigned as the main hot water heater at that time (maintaining the flow rate control valve 42 in a non-fully closed state), outputting a command for prohibiting combustion, The circulation pump 53 or 54 is operated (step SA2). Then, similarly to the acquisition process by the pump operating temperature acquisition processing unit 94, it is determined whether or not the detected incoming water temperature Th of the incoming water temperature sensor 40 of the water heater 3 after the elapse of a predetermined time from the start of circulation is lower than the determination temperature Tj. Determine (step SA3). The detected incoming water temperature Th represents the temperature of the hot water in the hot water storage tank 6 at that time, and the determination temperature Tj is a predetermined α ° C. (for example, 10 ° C.) from the pump operating temperature acquired in advance by the acquisition processing unit 94. Use the temperature value reduced by only. For example, if 60 ° C. is acquired as the pump operating temperature, Tj = 60 ° C.−10 ° C. = 50 ° C. The reason why the determination temperature Tj reduced by α ° C. is used is to reliably determine that an abnormality has occurred, and α ° C. is not simply a threshold for noise removal or the like. Thus, if the contact signal from the thermostat 61 is not output in spite of the fact that the temperature of the hot water in the hot water storage tank 6 is lower than the low temperature value, an abnormal state is surely occurring. A temperature value that can be determined (for example, the aforementioned 10 ° C.) may be set.

  The determination in step SA3 is performed on condition that the detected incoming water temperature Th is lower than the determination temperature Tj for 5 seconds for 5 seconds, for example. If these conditions are not satisfied (NO in step SA3), circulation is performed. The pump 53 or 54 is stopped (step SA4), waits for a predetermined waiting time (for example, 10 minutes) to elapse (NO in step SA5), and if it elapses (YES in step SA5), the processing in steps SA2 and SA3 is performed. repeat. That is, every time a predetermined waiting time elapses, it is checked whether or not the detected incoming water temperature is lower than the determination temperature Tj.

  If the detected incoming water temperature Th is lower than the determination temperature Tj in step SA3 (YES in step SA3), that is, if the state where the detected incoming water temperature Th is lower than the determination temperature Tj continues for 5 seconds, the thermostat 61 fails. It is determined that an abnormality has occurred because the output line of the thermostat 61 is disconnected and communication is interrupted. The determination by the processing up to step SA5 constitutes the processing content by the abnormality determination processing unit 92.

  If the determination that an abnormality has occurred is confirmed, an abnormality notification process is executed using the remote controller RC (step SA6). As the abnormality notification process, it may be displayed on the display unit of the remote controller RC that the abnormality relating to the temperature detection of the hot water storage tank 6 has occurred by text information, or that the same is announced by an artificial voice. Of course, the warning light may be turned on or blinking, or a warning buzzer may be sounded. By such an abnormality notification process, the user can quickly grasp that an abnormality relating to temperature detection has occurred, and can take subsequent measures at an early stage. As a result, it is possible to avoid at an early stage that the hot water storage tank 6 is not heated and the system goes down.

  Next, combustion by the main water heaters 3 and 3 is started, that is, the combustion prohibition command so far is canceled and the combustion operation is performed (step SA7), and circulation heating is performed. This circulating heating is continued until the detected incoming water temperature Th rises to the pump stop temperature Tjf (NO in step SA8), and if the detected incoming water temperature Th is equal to or higher than the pump stop temperature Tjf, for example, for 5 seconds ( YES in step SA8), the combustion of the water heaters 3 and 3 is prohibited and the operation of the circulation pump 53 or 54 is stopped (step SA9). Then, after the 60 minutes initially set as the determination time is switched to the emergency determination time (for example, 30 minutes) set shorter in advance than the initially set 60 minutes (step S10), the process proceeds to step SA1. It returns and repeats each process after step SA1. The reason for changing the judgment time is that the default judgment time is a time value used for judgment at the stage where it is unknown whether or not an abnormality has occurred, while it is determined that an abnormality has already occurred. Therefore, the emergency determination time thereafter is a time value used for determination for maintaining the temperature of the hot water in the hot water storage tank 6 within a predetermined temperature range (Tj to Tjf).

  By the above-described circulation heating by the emergency operation control unit 93, the circulation heating can be executed so that the temperature of the hot water in the hot water tank 6 is maintained within a predetermined temperature range even when no contact signal is output from the thermostat 61. It will be possible.

<Other embodiments>
In addition, this invention is not limited to the said embodiment, Other various embodiment is included. That is, in the said embodiment, although the example of the hot water storage system which controlled the number of water heaters 3, 3, ... by the system controller SC etc. was shown, it is not restricted to this, The number of the hot water heaters 3 which comprise a hot water storage system May be an arbitrary number of two or more.

  The present invention can also be applied to a hot water storage system having a configuration different from the hot water storage system shown in FIG. That is, for example, in the hot water storage system shown in FIG. 5A, a hot water storage temperature sensor (for example, platinum resistance thermistor) 61 a is installed in the hot water storage tank 6 instead of the thermostat 61, and the temperature detection output from the hot water storage temperature sensor 61 is adjusted in temperature. When the system controller SC receives a control signal related to ON / OFF of the circulation pump 53 or 54 from the temperature controller 61b, the system controller SC controls the pump control unit 55 or 56. Yes. In response to this, the temperature controller 61b is configured so that the user or the like inputs and sets the lower limit temperature and the upper limit temperature of hot water in the hot water storage tank 6 so that the circulating pump 53 is detected when the detection output of the hot water temperature sensor 61a becomes lower than the lower limit temperature. Alternatively, an operation signal 54 is output, and a stop signal is output when the temperature is raised to the upper limit temperature. The hot water storage temperature sensor 61a and the temperature regulator 61b constitute a temperature detecting means.

  In the hot water storage system shown in FIG. 5 (b), the hot water storage tank 6 and one hot water heater 3 are connected by a circulation path composed of a water inlet path 51 and a hot water outlet path 52. Then, the controller 31 built in the water heater 3 is configured to serve as both the system controller SC and the individual controller 30 in the embodiment.

  In the above-described embodiment, the pump operating temperature and the pump stop temperature are obtained in advance by the acquisition processing units 94 and 95. However, the present invention is not limited to this. Alternatively, it may be determined based on a set hot water temperature input and set in the remote controller RC. For example, the pump operating temperature = set hot water temperature−β ° C. (for example, β = 10) and the pump stop temperature = set hot water temperature−γ ° C. (for example, γ = 5) may be stored and set. As an example of input setting using the remote controller RC, for example, a special mode is provided in which threshold values related to the pump operating temperature and the pump stop temperature are input and set to the remote controller RC in advance as control temperature values used in emergency operation control. When the abnormality threshold value is memorized or when the abnormality determination processing unit 92 determines that an abnormality has occurred, when the abnormality is notified, the pump operating temperature or pump stop used in the emergency operation control simultaneously with the abnormality notification What is necessary is to urge the user or the like to input a threshold value related to the temperature and store the input threshold value. When notifying the abnormality, the user may be prompted to input a command for selecting whether to perform emergency operation control automatically or stop the system without executing emergency operation control. .

  Further, in the embodiment, the operation of the circulation pump 53 or 54 is stopped when the temperature rises to the pump stop temperature. However, during the emergency operation, the operation of the circulation pump 53 or 54 is continued and the main water heater 3 is operated. , 3 and the like may be controlled only for combustion operation and combustion stop. In this case, although the operation of the circulation pumps 53 and 54 continues to cause some loss in terms of drive energy, it is possible to reliably and quickly increase the temperature in heating the hot water in the hot water storage tank 6. .

3 Water heater 6 Hot water storage tank 30 Individual controller 40 Water temperature sensor (temperature sensor provided in the water heater)
51 Water entry route (circulation route)
52 Hot spring route (circulation route)
53, 54 Circulation pump (circulation means)
61 Thermostat (temperature detection means)
61a Hot water storage temperature sensor (temperature detection means)
61b Temperature controller (temperature detection means)
92 Abnormality determination processing unit (emergency operation control means)
93 Emergency operation control section (Emergency operation control means)
SC system controller (central control unit)
RC remote control (notification means)

Claims (7)

A hot water storage tank provided with temperature detection means, a water heater, and a circulation means for circulating hot water in the hot water storage tank through the water heater, the circulation means is operated based on the output of the temperature detection means A hot water storage system configured to be heated by the hot water heater,
In the case where the output of the temperature detection means maintains a state corresponding to the necessity of the heating operation despite the elapse of a predetermined determination time while the heating operation is stopped, forced circulation is started by the circulation means. A hot water storage system comprising emergency operation control means for performing emergency operation processing based on an output of a temperature sensor provided in the water heater. The hot water storage system according to claim 1,
The emergency operation process includes a hot water storage system including an abnormality notification process by a notification unit. The hot water storage system according to claim 1 or 2,
The emergency operation process includes a heating process in which the hot water heater is combusted based on the output of the temperature sensor to maintain the hot water in the hot water tank in a predetermined temperature range. The hot water storage system according to claim 3,
The emergency operation control means includes a temperature value stored in advance as a threshold value for the output of the temperature sensor for the heat treatment. The hot water storage system according to claim 3,
The emergency operation control means obtains a threshold value for the output of the temperature sensor for the heating process from a temperature sensor provided in the water heater during normal heating operation based on the output of the temperature detection means. Hot water storage system equipped with a department. The hot water storage system according to any one of claims 1 to 5,
The emergency operation control means prohibits the heat treatment by the water heater when executing the forced circulation, and whether or not an abnormality relating to the temperature detection means has occurred based on an output of a temperature sensor provided in the water heater. A hot water storage system configured to determine whether or not. The hot water storage system according to any one of claims 1 to 6,
The water heater is a plurality of water heaters connected in parallel to the circulation path from the hot water storage tank, and the emergency operation control means is a central control unit connected in communication with both the temperature detecting means and the water heater. Included in the hot water storage system.

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