JP6101246B2 - Hot water system - Google Patents

Description

  The present invention relates to a hot water supply system. In particular, the present invention relates to a hot water supply system in which an operation of feeding water to a heat exchanger by a magnet pump is performed.

  Conventionally, a heat exchanger heated by a burner, a water inlet and outlet pipe connected to the heat exchanger, a pump for feeding water to the heat exchanger, and a flow rate of water sent to the heat exchanger There is known a hot water supply system including a water amount sensor for detection. For example, in an instant hot water supply system, when a hot water supply operation is not performed, a pump is operated to form a circulation path with a water inlet line, a heat exchanger, and a hot water outlet line to circulate water. The circulating heat insulation operation is performed so that the water of the water reaches a predetermined temperature. Also, in the hot water storage hot water supply system, a hot water storage tank and a heat exchanger are connected by a return pipe as a water inlet pipe and an outgoing pipe as a hot water outlet to form a circulation path. Similarly, a hot water storage system is operated by operating a pump. Circulating and warming operation is performed so that the hot water is circulated between the tank and the heat exchanger, and the temperature of the hot water is maintained at a predetermined temperature. Furthermore, in a reheating hot water supply system having a reheating circuit for a bath, a tub and a heat exchanger are connected by a return pipe that is a water inlet pipe and a forward pipe that is a hot water outlet to form a circulation path and operate a pump. Thus, the bathtub water is circulated between the bathtub and the heat exchanger, and the circulation operation is performed so that the temperature of the bathtub water becomes a predetermined temperature.

  In these hot water supply systems, the combustion amount of the burner during operation is controlled based on the flow rate detected by the water amount sensor. However, when a pipe line is clogged or a pump malfunctions, water supply failure occurs. For this reason, when the flow rate detected by the water amount sensor becomes less than the predetermined flow rate before the operation ends normally, it is determined that a water supply failure has occurred and the operation is forcibly stopped by an error (for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2004-353981

  By the way, a magnet pump with little water leakage may be used as a pump of the hot water supply system. This type of magnet pump includes a driving magnet connected to a motor as a driving source, a driven magnet disposed opposite to the driving magnet and a partition wall in a casing constituting a part of the pipe line, And an impeller attached to the driven magnet. Accordingly, when the magnet pump is energized and the motor is driven, the driving magnet and the driven magnet are rotated by the magnetic attractive force, and the impeller is rotated accordingly, thereby supplying water.

  However, in the event of a momentary power interruption (instantaneous power failure or momentary large voltage drop), the rotation of the drive magnet stops immediately due to the motor stopping, but the driven magnet is moderated by the water flow in the pipeline. It will be in the state rotated to. Therefore, the magnet coupling between the driving magnet and the driven magnet is removed, and the pump is out of step. When the power supply recovers from the momentary power interruption and energization of the pump is resumed, the drive magnet starts to rotate at a high speed, but the driven magnet rotates at a low speed. A big difference occurs. As a result, when the driven magnet is not fixed to the driving magnet and the water flow stops, only the driving magnet rotates and water supply stops. Therefore, when a step-out due to a momentary power interruption as described above occurs, the flow rate detected by the water amount sensor becomes less than the predetermined flow rate, even though there is no clogging of the pipeline or pump failure, etc. There is a problem that the operation is stopped due to an error.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to stop unnecessary errors due to momentary power failure in a hot water supply system in which water is supplied to a heat exchanger by operating a magnet pump. Is to prevent.

The present invention
A water heater having a heat exchanger;
A magnet pump that delivers water to the heat exchanger;
A water amount detection unit for detecting a flow rate of water sent to the heat exchanger;
A control unit for determining a water supply failure based on the flow rate detected by the water amount detection unit,
During the operation of operating the magnet pump to supply water to the heat exchanger, the control unit temporarily energizes the magnet pump when the flow rate detected by the water volume detection unit is less than the predetermined step-out determination flow rate. After stopping, the energization to the magnet pump is resumed ,
If the flow rate detected by the water amount detecting unit is a first determination than the flow rate higher predetermined from out-of-step detection flow continues a predetermined first determination time, it determined that water failure has occurred due to aging, such as clogging of the conduit It is a hot water supply system.

  According to the hot water supply system described above, if the flow rate detected by the water amount detection unit becomes less than the predetermined step-out determination flow rate during the operation of operating the magnet pump, it is not determined immediately that the water supply is defective, but temporarily to the magnet pump. If the rotational speed of the follower magnet decreases during the energization stop, if the magnet coupling of the magnet pump is disengaged due to momentary power failure, the follower magnet is stopped. It can be fixed again to the drive magnet. If the pipeline is not clogged, the pump is not broken, etc., the flow rate is recovered by resuming energization of the magnet pump, so that unnecessary error stop can be avoided and the operation can be continued.

And when the magnetic pump is out of step due to momentary power interruption, water flow is not performed, so the flow rate is greatly reduced within a short time. On the other hand, when the pipeline is clogged due to deterioration over time or the water feeding capacity of the magnet pump is reduced, the flow rate is less reduced than when the step-out occurs. In addition, when water supply failure occurs due to the above-described factors of aging deterioration, since the flow rate once reduced is difficult to recover, water supply at the reduced flow rate continues for a certain time. Accordingly, if a flow rate less than the first determination flow rate that is higher than the step-out determination flow rate for determining a decrease in the flow rate due to the step-out of the magnet pump continues for the predetermined first determination time, water supply failure may occur due to aged deterioration factors. It can be determined that it has occurred.

In the above hot water supply system, preferably,
The control unit determines that the magnet pump has failed if the flow rate detected by the water amount detection unit is less than the step-out determination flow rate even when the energization of the magnet pump is stopped and restarted.

  According to the hot water supply system described above, even if the magnet pump is energized and restarted, if the flow rate detected by the water amount detection unit is less than the out-of-step determination flow rate, it is determined that the magnet pump has failed. It is possible to take measures such as stopping the vessel.

  As described above, according to the hot water supply system of the present invention, the magnet pump can be recovered from the step-out even if the flow rate decreases due to the step-out of the magnet pump caused by momentary power failure during the operation of operating the magnet pump. . Thereby, an unnecessary error stop can be prevented, and circulation operations such as a circulation heat insulation operation and an additional circulation operation in which the magnet pump is operated to supply water to the heat exchanger can be smoothly performed.

FIG. 1 is a schematic diagram illustrating an example of a hot water supply system according to an embodiment of the present invention. FIG. 2 is a flowchart showing an example of a control operation for determining a poor water supply during the circulating heat insulation operation in the hot water supply system according to the embodiment of the present invention.

  FIG. 1 is a schematic diagram of an instant hot water supply system to which the present invention is applied. As shown in FIG. 1, the instant hot water supply system of the present embodiment has an immediate hot water function capable of quickly supplying hot water to a mixing tap P1 provided at a hot water usage destination, and a heat exchanger. The water supplied to 21 is heated by the combustion exhaust gas of the gas from the burner 22 to generate hot water, the water inlet pipe 12 for supplying water to the heat exchanger 21, and the mixed faucet from the heat exchanger 21. A hot water supply line 13 for discharging hot water to P1, a water discharge line 14 for introducing water from the water supply source K to the mixing faucet P1, a water intake line 12 and a hot water supply line 13 bypassing the heat exchanger 21 A bypass line 15 to be connected and a circulation line 16 for guiding hot water discharged from the heat exchanger 21 to the water inlet line 12 by bypassing the mixing tap P1 are provided.

  The water inlet pipe 12 includes, in order from the upstream side, a water quantity sensor (water quantity detection unit) 24 that detects the flow rate of water flowing through the water inlet pipe 12, and hot water discharged from the heat exchanger 21 with respect to the hot water outlet pipe 13. A water distribution valve 26 capable of adjusting the mixing ratio with the water supplied from the bypass pipe 15 and a water inlet temperature sensor 27 for detecting the water temperature in the water inlet pipe 12 are provided. A hot water temperature sensor 30 for detecting the temperature of the hot water in the hot water pipe 13 is provided.

One end of the circulation pipe 16 is connected to the water inlet pipe 12 on the upstream side of the connection portion between the water inlet pipe 12 and the bypass pipe 15, and the other end is connected to the hot water outlet pipe 13 and the bypass pipe 15. The hot water outlet 13 is connected to the downstream side of the section. In addition, the circulation pipe 16 has a disk-type magnet pump 31 that is a circulation pump that operates at the time of the circulation heat insulation operation, and a check valve 32 that prevents water from flowing into the circulation pipe 16 from the water inlet pipe 12. And are provided. The circulation pipe 16 may be provided so as to connect the tap water pipe 13 and the drain pipe 14. Although not shown, the magnet pump 31 of the present embodiment is for driving fixed to the motor shaft. A drive chamber having a magnet and an impeller chamber having a driven magnet fixed to the impeller shaft and an impeller attached to the driven magnet are disposed via a partition wall. Therefore, when the motor rotates while the driven magnet is fixed to the driving magnet by the magnetic attractive force, the impeller rotates and water in the impeller chamber constituting a part of the piping is sent downstream.

  In the water heater 11, a gas regulating valve unit 23 that adjusts the amount of gas supplied to the burner 22 and a control unit (control unit) C that controls the operation of the entire hot water system are provided. The gas regulating valve unit 23, the water amount sensor 24, the water amount distribution valve 26, the incoming water temperature sensor 27, the hot water temperature sensor 30, and the magnet pump 31 are each connected to the control unit C through electrical wiring. Although not shown, an operation terminal for instructing the operation of the hot water supply system is connected to the control unit C through electric wiring.

  The control unit C comprises a microcomputer, and includes a CPU, a ROM, a RAM, a timer, and the like. When the hot water supply operation for discharging hot water at a predetermined temperature from the hot water outlet of the mixing tap P1 and the hot water supply operation are not performed, Executes a circulating heat insulation operation that keeps the water in the pipeline warm. Although not shown in the drawing, the control unit C controls the combustion amount of the burner 22 so that the tapping temperature detected by the tapping temperature sensor 30 becomes the hot water supply set temperature when the mixing tap P1 is opened as a circuit configuration. The hot water supply operation control unit to be controlled and the hot water temperature detected by the hot water temperature sensor 30 while the magnet pump 31 is operated and water is circulated in the pipe line when the hot water supply operation is not performed are In order to control the amount of gas to the burner 22, the circulation heat insulation operation control unit that controls the combustion amount of the burner 22, the pump control unit that controls the operation of the magnet pump 31, and the gas regulating valve unit 23 are proportionally controlled. Based on the gas amount control unit, the flow rate control unit that adjusts the opening of the water amount distribution valve 26 to control the flow rate to the heat exchanger 21, and the flow rate detected by the water amount sensor 24 during the circulating heat insulation operation. Correspondence relationship between water supply failure determination unit for determining water supply failure due to step-out of pump 31, clogged pipe, etc., determination flow rate and determination time for determining water supply failure, flow rate, incoming water temperature, hot water supply set temperature, and combustion amount And a data storage unit storing various operation programs.

  When the hot water supply operation is executed in the hot water supply system of the present embodiment, the user opens the mixed water tap P1, and the flow rate detected by the water amount sensor 24 is a predetermined minimum working water amount (for example, 2.7 L / min)), the control unit C ignites the burner 22 by adjusting the gas amount supplied to the burner 22 by the gas regulating valve unit 23 to the ignition gas amount. Then, based on the flow rate detected by the water amount sensor 24, the incoming water temperature detected by the incoming water temperature sensor 27, and the hot water supply set temperature, the amount of water distributed so that the hot water temperature detected by the hot water temperature sensor 30 becomes the hot water supply set temperature. While adjusting the opening degree of the valve 26, the gas regulating valve unit 23 proportionally controls the gas amount to the burner 22. When the flow rate detected by the water amount sensor 24 is less than the minimum working water amount due to the closing of the mixed water tap P1, the burner 22 is extinguished.

  Next, a control operation for determining a water supply failure when the circulating heat insulation operation for operating the magnet pump 31 is executed in the hot water supply system of the present embodiment will be described with reference to the flowchart of FIG. In the hot water supply system according to the present embodiment, the temperature of the hot water in the hot water discharge pipe 13 detected by the hot water temperature sensor 30 is a predetermined heat retention start temperature (for example, 40 ° C.) in a state where the hot water supply operation is not executed. When the temperature becomes below, the circulating heat insulation operation is started, and when the temperature of the hot water in the hot water discharge line 13 becomes equal to or higher than a predetermined heat insulation setting temperature (for example, 60 ° C.), the circulation heat insulation operation is set to stop.

  When the circulation heat insulation operation is started in a state where the hot water supply operation is not executed, the control unit C energizes the magnet pump 31 and rotates the motor at a predetermined rotation speed (step ST1). Then, a circulation path is formed in which water in the heat exchanger 21 returns to the heat exchanger 21 through the hot water discharge line 13, the circulation line 16, and the incoming water line 12.

  When the flow rate detected by the water amount sensor 24 becomes equal to or higher than the minimum working water amount (for example, 2.7 L / min), the ignition process is executed and the burner 22 is ignited as in the hot water supply operation. Then, based on the flow rate detected by the water amount sensor 24, the incoming water temperature detected by the incoming water temperature sensor 27, and the heat retention set temperature, the hot water temperature detected by the hot water temperature sensor 30 becomes a predetermined heat retention set temperature. The opening of the water distribution valve 26 is adjusted, and the gas amount to the burner 22 is proportionally controlled by the gas adjustment valve unit 23 (step ST2). As a result, the water in the pipe is heated, so when the mixing faucet P1 is opened, hot water is quickly supplied to the hot water outlet through the hot water pipe 13.

  During the circulating heat insulation operation, in the hot water supply system of the present embodiment, it is determined whether there is a water supply failure or a failure of the magnet pump 31 due to factors of aging such as step-out and clogging of pipes.

  First, in order to detect a decrease in the flow rate due to a cause of aging deterioration, it is determined whether or not a flow rate lower than a predetermined first determination flow rate (for example, 6 L / min) continues for a predetermined first determination time (for example, 10 seconds). Determination is made (step ST3). When the clogging of the pipeline progresses due to aging deterioration, the flow rate decreases even if the magnet pump 31 is operated at a predetermined rotational speed, but the flow rate decreases less than when the step-out occurs due to momentary power failure. The reduced flow rate continues for a certain time. Therefore, the first determination flow rate is set to a flow rate higher than the step-out determination flow rate when determining poor water supply due to step-out, and the first determination time is set to a time longer than the step-out determination time. .

  If the flow rate less than the first determination flow rate does not continue for the first determination time during the circulation heat insulation operation (No in step ST3), the flow rate detected by the water amount sensor 24 is monitored and a predetermined step-out determination flow rate (for example, 0 .5L / min) is determined whether or not the flow rate continues for a predetermined step-out determination time (for example, 2 seconds) (step ST4). In other words, when the magnetic pump 31 loses its power due to a momentary power failure, the magnet coupling between the driving magnet and the driven magnet is disengaged, so that even if the driving magnet rotates, no water is supplied. The flow rate is greatly reduced compared to before the step-out. Therefore, if a flow rate lower than the step-out determination flow rate is detected even in a short time, it is possible that the step-out of the magnet pump 31 has occurred.

  In the step-out determination, when the flow rate detected by the water amount sensor 24 is less than the step-out determination flow rate and the step-out determination time continues (Yes in step ST4), the control unit C indicates “1” in the history of the number of water supply failures. Is added to update the number of water supply failures (step ST5). If the number of water supply failures is not a predetermined number (for example, 2 times) (No in step ST6), the energization to the magnet pump 31 is temporarily predetermined. Is stopped (for example, 10 seconds) (steps ST7 to ST8). As a result, when the power supply recovers from the momentary power failure and only the driving magnet rotates at a high speed, the driving magnet stops rotating, so if the flow rate decreases and the rotational speed of the driven magnet decreases, The difference in rotational speed between the driving magnet and the driven magnet is reduced, and the driven magnet can be fixed to the driving magnet again by the magnetic attractive force. In addition, the stop time of energization to the magnet pump 31 is appropriately set according to the flow rate, the size of the pipeline, and the like during the circulating heat insulation operation.

  When the stop time of energization to the magnet pump 31 has elapsed (Yes in step ST8), the control unit C resumes energization to the magnet pump 31 (step ST9). Since the burner 22 is extinguished because the flow rate is reduced, the flow rate detected by the water amount sensor 24 during the circulating heat insulation operation is performed when the flow rate is restored to the minimum working water amount or more, as described above. It is determined whether or not the first determination flow rate is continued for the first determination time, and whether or not the step-out determination flow rate is continued for the step-out determination time (steps ST2 to ST4).

  After temporarily stopping and resuming energization of the magnet pump 31, the flow rate detected by the water volume sensor 24 does not continue below the first determination flow for the first determination time, and continues below the step-out determination flow for less than the step-out determination flow. If not (No in Steps ST3 and ST4), there is no water supply failure due to the cause of aged deterioration, and the magnet pump 31 has recovered from the step-out by temporarily stopping and resuming energization of the magnet pump 31. Therefore, the number of water feeding failures is confirmed, and if the number of water feeding failures is stored, the number of water feeding failures is returned to “0” (steps ST10 and ST11). As a result, if the flow rate detected by the water volume sensor 24 during the next circulating heat insulation operation falls below the step-out determination flow rate, temporary energization of the magnet pump 31 is again stopped and restarted, and an error immediately occurs. Stopping can be prevented.

  On the other hand, after temporarily stopping and resuming energization of the magnet pump 31, the flow rate detected by the water amount sensor 24 does not continue below the first determination flow rate for the first determination time, but again the flow rate detected by the water amount sensor 24. If the step-out determination time is continued for less than the step-out determination flow rate (No in step ST3, Yes in step ST4), it is determined that the water supply state has not returned even by temporarily stopping and resuming energization of the magnet pump 31. it can. For this reason, when the history of the number of water supply failures becomes a predetermined number of times (for example, twice) (Yes in step ST6), it is determined that a failure has occurred in the magnet pump 31, and the energization to the magnet pump 31 is stopped. Then, the circulating heat insulation operation is stopped by error (steps ST12 and ST13).

  If the flow rate detected by the water amount sensor 24 gradually decreases during the circulation heat insulation operation and continues below the first determination flow rate for the first determination time (Yes in step ST3), there is a risk of clogging of the pipeline due to deterioration over time. Therefore, an error warning is notified from an operation terminal (not shown) or the like (step ST14). Then, the flow rate detected by the water amount sensor 24 is further reduced to be less than the second determination flow rate (for example, 4 L / min) that is higher than the step-out determination flow rate but lower than the first determination flow rate (for example, 4 L / min). 10 seconds), if the water is not supplied to the heat exchanger 21 at a sufficient flow rate and the magnet pump 31 is overloaded, the energization of the magnet pump 31 is stopped and the circulation heat insulation operation is performed. The error is stopped (steps ST16 and ST17). Thereby, it can prevent that the said malfunction arises by the clogging of the pipe line by aged deterioration, etc.

  As described in detail above, according to the hot water supply system of the present embodiment, the flow rate detected by the water amount sensor 24 is removed during the circulation heat insulation operation in which the magnet pump 31 is operated to circulate water through the heat exchanger 21. Since the energization to the magnet pump 31 is temporarily stopped when the flow rate is less than the adjustment determination flow rate, when the step-out of the magnet pump 31 occurs due to momentary power interruption, the rotation of the drive magnet causes the drive magnet to The difference in rotational speed of the driven magnet is reduced, and the driven magnet can be fixed to the driving magnet again. And after stopping electricity supply temporarily, the magnet pump 31 can be returned from a step-out by restarting electricity supply. Thereby, the circulation heat insulation operation can be continued without stopping the error. And according to the said hot-water supply system, since the magnet pump 31 can be returned from step-out without stopping an error, the user does not need to reset the hot-water supply system. Thereby, usability can be improved.

  Further, according to the hot water supply system of the above-described embodiment, when the flow rate detected by the water amount sensor 24 is less than the step-out determination flow rate even when the energization of the magnet pump 31 is stopped and restarted, the magnet pump 31. Therefore, it is possible to reliably prevent the circulating and warming operation from being continued in a state where water is not supplied to the heat exchanger 21.

Furthermore, according to the hot water supply system of the above embodiment, apart from the out-of-step determination due to momentary power failure, the flow rate detected by the water sensor 24 is lower than the first determination flow rate that is higher than the out-of-step determination flow rate for the first determination time. In this case, since it is determined that the water supply is poor due to aging deterioration such as clogging of the pipeline, it can be determined separately from the water supply failure due to step-out. Thereby, it is possible to determine a water supply failure due to aged deterioration and a water supply failure due to a momentary power failure while performing a circulating heat insulation operation for operating the magnet pump 31. Therefore, it is possible to provide a more convenient hot water supply system.
(Other embodiments)
(1) In the above embodiment, the circulating heat insulation operation in the instant hot water supply system has been described. However, the present invention can be applied to any operation that operates a magnet pump to feed water to a heat exchanger. In the above-described embodiment, the hot water supply system has been described. However, the hot water supply system that operates the magnet pump such as the hot water storage type hot water supply system having the hot water storage tank and the reheating water supply system having the recirculation circuit as described above is performed. The present invention can be applied to a system.
(2) In the above embodiment, the energization of the magnet pump is stopped and restarted only once, but may be performed a plurality of times.
(3) In the above embodiment, the first and second determination flow rates are set in order to determine water supply failure due to aging deterioration, but only the first determination flow rate in one stage may be set.
(4) In the above embodiment, the step-out determination is performed based on whether the flow rate less than the step-out determination flow continues for the step-out determination time, but without waiting for the step-out determination time to elapse, The energization may be stopped.

11 Water heater 24 Water sensor (Water detector)
31 Magnet pump 12 Inlet pipe 13 Hot water outlet 21 Heat exchanger 31 Magnet pump C Control unit (control unit)

Claims (2)

A water heater having a heat exchanger;
A magnet pump that delivers water to the heat exchanger;
A water amount detection unit for detecting a flow rate of water sent to the heat exchanger;
A control unit for determining a water supply failure based on the flow rate detected by the water amount detection unit,
During the operation of operating the magnet pump to supply water to the heat exchanger, the control unit temporarily energizes the magnet pump when the flow rate detected by the water volume detection unit is less than the predetermined step-out determination flow rate. After stopping, the energization to the magnet pump is resumed ,
If the flow rate detected by the water amount detecting unit is a first determination than the flow rate higher predetermined from out-of-step detection flow continues a predetermined first determination time, it determined that water failure has occurred due to aging, such as clogging of the conduit Hot water system. The hot water supply system according to claim 1 ,
The controller is a hot water supply system that determines that a failure of the magnet pump has occurred when the flow rate detected by the water amount detection unit is less than the step-out determination flow rate even when the energization of the magnet pump is stopped and restarted.

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