JP2021188850A - Hot water supply system - Google Patents

Abstract

To provide a technology which has a function of checking multiple electromagnetic valves installed in a gas duct, and can suppress the frequency that combustion continues after the electromagnetic valve to be checked is blocked.SOLUTION: In a hot water supply system 1, a control unit executes: a first control of making hot water supply switch electromagnetic valves 46, 46... into an open state while making a gas main electromagnetic valve 42 into a block state when a combustion end condition is established; and a second control of making the gas main electromagnetic valve 42 into an open state while the hot water supply switch electromagnetic valves 46, 46... are made into a block state. A determination unit executes: a first determination process of determining whether combustion of a gas burner 4 is detected by a detective unit during the first control; and a second determination process of determining whether combustion of the gas burner 4 is detected by the detective unit during the second control. A control unit executes the first control if time condition or apparatus condition is satisfied when the combustion end condition is established, and otherwise executes the second control.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a hot water supply system.

Patent Document 1 discloses a water heater that burns fuel to heat water in a heat exchanger. This water heater is provided with a burner and a gas supply pipe that serves as a gas supply path to the burner. It is composed of the branch pipes of. A main gas solenoid valve and a gas proportional valve are provided in the main pipe, and a hot water supply gas solenoid valve is provided in each branch pipe. In this water heater, gas is supplied to the burner by opening the original gas solenoid valve and the hot water supply gas solenoid valve at the same time, and the burner is ignited by being continuously discharged from the spark plug. Then, in this water heater, the original gas solenoid valve and the hot water supply gas solenoid valve are closed after the burner is extinguished.

Japanese Unexamined Patent Publication No. 2016-20351

In the water heater of Patent Document 1, there is a possibility that an abnormality may occur in the original gas solenoid valve or the hot water supply gas solenoid valve so that the gas supply path cannot be reliably blocked. As a method of detecting such an abnormality, when extinguishing the burner, control is performed so that only one of the original gas solenoid valve and the hot water supply gas solenoid valve is closed first, and whether the burner combustion continues. By detecting whether or not it is present, a method of detecting an abnormality in one of the above solenoid valves can be considered. In a water heater that employs such an abnormality detection method, it is possible to inspect the abnormality of both solenoid valves by switching the solenoid valve to be closed first for each fire extinguishing operation.

However, in this water heater, if the original gas solenoid valve is closed first, the fire extinguishing will be completed after the gas remaining in the gas flow path on the downstream side of the original gas solenoid valve has finished burning. .. That is, since the water heater continues to burn even after the original gas solenoid valve is closed, there is a concern about the demerit caused by the extra heat being applied to the water in the heat exchanger. As a disadvantage of this, for example, the water heated after the original gas electromagnetic valve is closed remains in the water heater, and the feedback temperature is controlled based on the temperature of the heated residual water at the next hot water discharge. There is a problem that it takes time to bring the hot water temperature close to the set temperature. In addition, there is a possibility that disadvantages other than such a problem may occur.

The present disclosure provides a technique that has a function of inspecting a plurality of solenoid valves provided in a gas flow path and can suppress the frequency of continuous combustion after closing the solenoid valves to be inspected.

The hot water supply system, which is one of the present disclosures, is a water passage pipe through which water introduced from the outside passes, a burner that burns combustion gas to generate exhaust gas, and a flow path that supplies the combustion gas to the burner. A gas flow path, a first electromagnetic valve that switches between an open state in which the gas flow path is open and a closed state in which the gas flow path is closed, and an open state in which the gas flow path is opened at a position downstream of the first electromagnetic valve. The second electromagnetic valve that switches to the closed closed state, the heat exchanger that is provided in the middle of the water passage pipe and transfers the heat of the exhaust gas to the water passing through the inside of the water passage pipe, and the combustion end condition are The first control that opens the second electromagnetic valve while closing the first electromagnetic valve when it is satisfied, and the first control that closes the second electromagnetic valve when the combustion end condition is satisfied. 1 A control unit that performs a second control that opens the electromagnetic valve, a detection unit that detects combustion in the burner, and a detection unit that detects combustion in the burner during the first control. A determination unit that performs a first determination process for determining whether or not combustion and a second determination process for determining whether or not combustion in the burner is detected by the detection unit during the second control are provided. The control unit performs the first control when the predetermined time condition or the equipment condition is satisfied when the combustion end condition is satisfied, and performs the second control when the condition is not satisfied.

The hot water supply system according to one aspect of the present disclosure can inspect a plurality of solenoid valves provided in the gas flow path, and can suppress the frequency of continuous combustion after closing the solenoid valves to be inspected.

FIG. 1 is a schematic circuit diagram illustrating a hot water supply system according to the first embodiment. FIG. 2 is a block diagram schematically illustrating a controller and a remote controller constituting the hot water supply system according to the first embodiment. FIG. 3 is a flowchart illustrating the flow of hot water supply control performed in the hot water supply system of the first embodiment.

The following description relates to an example of an embodiment of a hot water supply system. The features of [1] to [3] shown below may be combined in any manner in a consistent manner.

[1] A water passage pipe through which water introduced from the outside passes, a burner that burns combustion gas to generate exhaust gas, a gas flow path that supplies the combustion gas to the burner, and the gas flow. A first electromagnetic valve that switches between an open state and a closed state in which the path is open, and a first electromagnetic valve that switches between an open state in which the gas flow path is opened and a closed state at a position downstream of the first electromagnetic valve. The two electromagnetic valves, a heat exchanger provided in the middle of the water passage pipe and transmitting the heat of the exhaust gas to the water passing through the inside of the water passage pipe, and the first electromagnetic wave when the combustion end condition is satisfied. The first control in which the second electromagnetic valve is opened while the valve is closed, and the first electromagnetic valve in the open state while the second electromagnetic valve is closed when the combustion end condition is satisfied. A control unit that performs the second control, a detection unit that detects combustion in the burner, and a first that determines whether or not combustion in the burner is detected by the detection unit during the first control. The control unit includes a determination unit that performs a determination process and a second determination process for determining whether or not combustion in the burner is detected by the detection unit during the second control, and the control unit includes the combustion unit. A hot water supply system that performs the first control when a predetermined time condition or equipment condition is satisfied when the end condition is satisfied, and performs the second control when the end condition is not satisfied.

The hot water supply system of the above [1] can detect the presence or absence of an abnormality in the first solenoid valve by performing the first determination process, and detect the presence or absence of an abnormality in the second solenoid valve by performing the second determination process. can do. Therefore, this hot water supply system can inspect a plurality of solenoid valves provided in the gas flow path. Moreover, this hot water supply system performs the first control when the combustion end condition is satisfied and when the predetermined time condition or the equipment condition is satisfied. As described above, in the above-mentioned hot water supply system, since the first control is limited by the time condition or the equipment condition, the frequency of the inspection by the first control, that is, the first solenoid valve on the upstream side is the inspection target. The frequency can be reduced. Therefore, this hot water supply system can suppress the frequency of continuous combustion after closing the solenoid valve to be inspected.

[2] A blower that blows air into the heat exchanger, a drive unit that starts driving the blower when the blower start condition is satisfied, and a drive unit that stops the drive of the blower when the blower stop condition is satisfied. The hot water supply system according to [1], wherein the control unit performs the first control before the blowing operation in which the driving unit drives the blower according to the establishment of the blowing start condition.

In the hot water supply system of [2] above, combustion continues after the first electromagnetic valve is closed by the first control, and even if the vicinity of the heat exchanger is heated by this combustion, heat exchange is performed by driving the blower after the first control. The vessel can be cooled. Therefore, even if excess heat is applied to the water in the heat exchanger due to the combustion after the first electromagnetic valve is closed, the temperature rise in the water in the heat exchanger can be suppressed or lowered by the subsequent cooling. , The demerits caused by the extra heat added to the water in the heat exchanger can be surely suppressed.

[3] The driving unit drives the blower when the self-diagnosis condition is satisfied, and the control unit performs the first control before the blowing operation according to the satisfaction of the self-diagnosis condition [2]. ] The hot water supply system described in.

In the hot water supply system of [3] above, combustion continues after the first electromagnetic valve is closed by the first control, and even if the vicinity of the heat exchanger is heated by this combustion, the heat exchanger is driven by the drive of the blower after the first control. Can be cooled, and the demerits caused by the extra heat applied to the water in the heat exchanger can be surely suppressed. Moreover, since the above-mentioned demerits can be suppressed by effectively utilizing the driving of the blower performed when the self-diagnosis condition is satisfied, the dedicated operation of driving the blower only for suppressing the above-mentioned demerits is omitted or reduced. be able to.

<First Embodiment>
The following description relates to the first embodiment.
(Basic configuration)
The hot water supply system 1 shown in FIG. 1 is configured as a bath / hot water supply system having a hot water supply function to the bathtub 60 and a heating function of water in the bathtub, and mainly includes a hot water supply side circuit 2 and a bath side circuit 3. The hot water supply side circuit 2 includes a water inlet pipe 12, a hot water outlet pipe 10, a gas burner 4 (burner), a hot water supply side heat exchanger 6 (heat exchanger), etc., and functions as a path for heating tap water supplied from the outside to discharge hot water. do. The bath side circuit 3 is provided with a gas burner 54 (bath side burner), a bath side heat exchanger 56, a pipe 66, a circulation pump 62, a thermista 64, 65, etc. Used for.

In the hot water supply side circuit 2, the pipeline composed of the water inlet pipe 12, the heat transfer pipe 8a, the pipe 20, the heat transfer pipe 7a, and the hot water outlet pipe 10 functions as the hot water supply side water passage. The water inlet pipe 12 is configured as a path through which water flows from the water inlet 16, and the hot water outlet pipe 10 is configured as a path for sending hot water to the hot water outlet 18. The gas burner 4 corresponds to an example of a burner, and is a portion that burns a gas (combustion gas) to generate an exhaust gas. The hot water supply side heat exchanger 6 corresponds to an example of a heat exchanger, and is water that passes through a hot water supply side water passage (a pipe line composed of a water inlet pipe 12, a heat transfer pipe 8a, a pipe 20, a heat transfer pipe 7a, and a hot water outlet pipe 10). It is a part that transfers the heat generated by the gas burner 4 to boil hot water, and is provided at a position in the middle of the hot water supply side water passage, and is generated by combustion in the gas burner 4 with respect to the water passing through the inside of the hot water supply side water passage. It works to transfer heat. The hot water supply side heat exchanger 6 includes a primary heat exchanger 7 and a secondary heat exchanger 8, and the primary heat exchanger 7 is arranged in the hot water supply combustion chamber 90 on the upstream side of the combustion exhaust path of the gas burner 4. The secondary heat exchanger 8 is arranged on the downstream side of the combustion / exhaust path in the hot water supply / combustion chamber 90.

In the hot water supply side circuit 2, a water inlet pipe 12 is connected to the inlet of the secondary heat exchanger 8 so as to supply tap water. The water inlet pipe 12 has a thermistor 25 as a water temperature detector for detecting the temperature of water passing through the water pipe 12 (that is, the water temperature at a position upstream of the heat exchanger in the water pipe), and a passage through the water pipe 12. A water amount sensor 34 is provided as a water amount detecting unit for detecting the amount of water (that is, the amount of water flowing through the water pipe). The heat transfer tube 8a of the secondary heat exchanger 8 is connected to the downstream side of the water inlet pipe 12, and the heat transfer tube 8a of the secondary heat exchanger 8 and the heat transfer tube 7a of the primary heat exchanger 7 are further downstream thereof. The pipe 20 connecting with and is connected. The heat transfer tube 7a of the primary heat exchanger 7 is connected in a configuration connected to the pipe 20, and the hot water outlet pipe 10 is configured to discharge hot water heated by the primary heat exchanger 7 to the outlet of the primary heat exchanger 7. Is connected. The hot water outlet pipe 10 is provided with a thermistor 26 for detecting the temperature of the water in the hot water outlet pipe 10. In this configuration, the water inlet pipe 12, the heat transfer pipe 8a, the pipe 20, the heat transfer pipe 7a, and the hot water outlet pipe 10 correspond to an example of the water passage pipe, and pass water introduced from a water pipe (not shown) provided outside the hot water supply system 1. Functions as a flow path.

The hot water supply side heat exchanger 6 functions to recover the latent heat by the secondary heat exchanger 8 after recovering the sensible heat of the combustion exhaust by the primary heat exchanger 7. Specifically, the primary heat exchanger 7 includes a heat transfer tube 7a that serves as a water passage path in the primary heat exchanger 7, and is used for combustion exhaust generated by the gas burner 4 with respect to water passing through the heat transfer tube 7a. The heat of combustion contained in the heat is transferred, and the heat energy of the sensible heat is transferred to the water for heat exchange. Further, the secondary heat exchanger 8 includes a heat transfer tube 8a that serves as a water passage path in the secondary heat exchanger 8, and the combustion exhaust generated by the gas burner 4 is primary for the water passing through the heat transfer tube 8a. The heat of combustion after passing through the heat exchanger 7 is transferred, and the heat of latent heat is exchanged so as to be transferred to water.

As a water flow path that bypasses between the water inlet pipe 12 and the hot water outlet pipe 10, a bypass path 14 configured as a water flow path different from the hot water supply side heat exchanger 6 is provided. The bypass path 14 has a configuration (for example, a configuration that can be changed steplessly) that can change from a closed state in which the water flow of the bypass path 14 is blocked to an open state (a state in which the opening degree is increased from the closed state). An eggplant bypass valve 32 is provided. In the water inlet pipe 12, a water flow control valve 33 is provided on the upstream side of the branch position to which the bypass path 14 is connected. The water flow control valve 33 includes a motor in which the rotation angle of the drive shaft is controlled in response to an instruction from the controller 22, and the water inlet pipe 12 is continuously changed to various openings between the closed state and the fully open state. It is a structure that can be done. In this configuration, the water flow control valve 33 functions to adjust the amount of water flowing through the water pipe.

The gas flow path 40 for supplying gas to the gas burner 4 is provided with a gas source solenoid valve 42, a hot water supply gas proportional control valve 44, a hot water supply switching solenoid valve 46, 46, and so on, respectively, from the upstream side. The gas flow path 40 has a main flow path 40A whose upstream end is connected to the gas supply source side, and branch flow paths 40B and 40B which are connected to the downstream end of the main flow path 40A and are branched from the main flow path 40A toward each gas burner 4.・ ・ Including and. The gas source solenoid valve 42 corresponds to an example of the first solenoid valve, and is provided in the main flow path 40A, and switches between an open state in which the main flow path 40A (gas flow path 40) is open and a closed state in which the main flow path is closed. .. When the gas source solenoid valve 42 is in the open state, gas can flow from the upstream side to the downstream side of the gas source solenoid valve 42. When the gas source solenoid valve 42 is in the closed state, gas does not flow from the upstream side to the downstream side of the gas source solenoid valve 42. The hot water supply switching solenoid valves 46, 46 ... Are provided in each branch flow path 40B, 40B ... Each of the hot water supply switching solenoid valves 46, 46 ... Corresponds to an example of the second solenoid valve, and the gas flow path 40 is open and closed at a position downstream of the gas source solenoid valve 42. Switch to. When the hot water supply switching solenoid valve 46 is in the open state, gas can flow from the upstream side to the downstream side of the hot water supply switching solenoid valve 46. When the hot water supply switching solenoid valve 46 is in the closed state, gas does not flow from the upstream side to the downstream side of the hot water supply switching solenoid valve 46.

A switching solenoid valve 53 is provided in the bath side branch flow path 40C from the gas flow path 40 connected to the gas burner 54 (bath side burner). The hot water supply gas proportional control valve 44 and the hot water supply switching solenoid valve 46 function to adjust the amount of gas to the gas burner 4.

The hot water supply system 1 includes a hot water supply ignition plug 35, a hot water supply frame rod 36, a bath ignition plug 37, and a bath frame rod 38. The hot water supply frame rod 36 corresponds to an example of a detection unit, and functions as a detection unit for detecting combustion in the gas burner 4 together with the controller 22 described later. The bath frame rod 38 detects combustion in the gas burner 54. The number of hot water supply frame rods 36 may be one or two or more.

The hot water supply system 1 includes a fan 48 and a fan motor 49. The fan 48 corresponds to an example of a blower, and operates to send air into the hot water supply side heat exchanger 6. The fan 48 is provided below the hot water supply combustion chamber 90, and supplies combustion air to each gas burner 4 (burner) and gas burner 54 (bath side burner). The fan motor 49 corresponds to an example of a drive unit, and together with the controller 22 described later, starts driving the fan 48 when the ventilation start condition is satisfied, and stops driving the fan 48 when the ventilation stop condition is satisfied. Functions as a drive unit.

In the bath side circuit 3, the pipe 66 has a forward pipe 67 for guiding water from the bathtub 60 side to the bath side heat exchanger 56 side and water from the bath side heat exchanger 56 side to the bathtub 60 side. A return pipe 68 for guiding and an intermediate pipe 69 connected to the outgoing pipe 67 and the return pipe 68 and passing through the inside of the bath side heat exchanger 56 are provided. The bath side heat exchanger 56 includes a bath primary heat exchanger 57 and a bath secondary heat exchanger 58, and functions to transfer the heat generated by the gas burner 54 (bath side burner) to the water passing through the pipe 66. .. The going pipe 67 is provided with a circulation pump 62 and a thermistor 64 (bath thermistor) for detecting the temperature of water passing through the going pipe 67. The circulation pump 62 is a device for flowing water in the pipe 66. A drop pipe 70 branched from the hot water outlet pipe 10 is connected to the return pipe 68, and the drop pipe 70 is provided with a hot water supply solenoid valve 72 and a drop water amount sensor 74. The drop pipe 70 is a path for passing hot water from the hot water supply side water passage of the hot water supply side circuit 2 to the pipe 66 (circulation passage) of the bath side circuit 3.

The hot water supply system 1 is provided with the controller 22 shown in FIGS. 1 and 2. The controller 22 shown in FIG. 2 is configured as an interface for communicating with the outside, for example, a control unit 22A configured as a known microcomputer or the like, a memory 22B configured as a known semiconductor memory or the like, and the like. It is provided with a communication unit 22C. The controller 22 is configured to be able to acquire signals from various sensors provided in the hot water supply side circuit 2 and the bath side circuit 3, and can control various actuators provided in the hot water supply side circuit 2 and the bath side circuit 3. ..

The controller 22 corresponds to an example of a detection unit, a control unit, a determination unit, and a drive unit. The controller 22 can perform the first control of closing the gas source solenoid valve 42 and opening the hot water supply switching solenoid valves 46, 46 ... When the combustion end condition is satisfied. During the first control, when the gas source solenoid valve 42 is normally blocked (when the gas flow in the gas flow path 40 is blocked), gas is sent from the outside of the hot water supply system 1 to the gas burner 4. Not supplied. When the combustion end condition is satisfied, the controller 22 can perform the second control of closing the hot water supply switching solenoid valves 46, 46 ... And opening the gas source solenoid valve 42. During the second control, if the hot water supply switching solenoid valves 46, 46 ... Are normally blocked (when the gas flow in the gas flow path 40 is blocked), the gas burner is installed from the outside of the hot water supply system 1. No gas is supplied to 4. The controller 22 may perform a first determination process for determining whether or not combustion in the gas burner 4 is detected based on a signal from the hot water supply frame rod 36 during the first control. The controller 22 may perform a second determination process for determining whether or not combustion in the gas burner 4 is detected based on a signal from the hot water supply frame rod 36 during the second control. The controller 22 selectively performs the first control among the first control and the second control when the combustion end condition is satisfied and the predetermined condition (at least one of the time condition and the equipment condition) is satisfied. .. In this case, the second control is not performed. Further, when the combustion end condition is satisfied, the controller 22 performs the second control of the first control and the second control when the predetermined condition (at least one of the time condition and the equipment condition) is not satisfied. conduct. In this case, the first control is not performed.

Of the above time conditions and the above equipment conditions, the above time conditions are time conditions such as "a predetermined time has been reached" and "a predetermined operation (for example, a fire extinguishing operation) has been performed in a predetermined time zone". It may be "a certain time has passed since the last fire extinguishing", "a predetermined time has passed since the last driving end of the fan 48", and "a predetermined time has passed since the last self-diagnosis was completed". It may be an elapsed time condition such as "the combustion of the gas burner 4 has started".

Of the above time conditions and the above equipment conditions, the above equipment conditions specifically include "the predetermined equipment provided in the hot water supply system 1 is in the predetermined state" or "the predetermined equipment provided in the hot water supply system 1". The conditions for achieving the predetermined state have been satisfied. " The predetermined device is not particularly limited, and is, for example, a gas burner 4, a fan 48, a water amount sensor 34, and the like. The device condition may be "a condition for starting the operation of a predetermined device is satisfied" or "a condition for prohibiting the operation of a predetermined device is satisfied". It may be "a condition for suspending the operation of a predetermined device for a certain period of time is satisfied" or "a condition for ending the operation of a predetermined device is satisfied". Further, the device condition may be "the operation of the predetermined device has been completed", "the operation of the predetermined device has started", or "the predetermined device has started". The operation of is prohibited. " Specifically, the equipment condition may be a condition in which the heat exchanger is cooled or the heat is suppressed according to the establishment of the equipment condition. More specifically, the equipment condition may be such that the fan 48 is driven according to the establishment of the equipment condition, and the hot water supply side heat exchanger 6 is cooled by the driving of the fan 48. Alternatively, the equipment condition is such that the ignition of the gas burner 4 is prohibited for a certain period according to the establishment of the equipment condition, and the heat exchanger 6 on the hot water supply side is cooled or suppressed by the continuation of such ignition suppression for a certain period. Conditions may be met. In the following description, predetermined equipment conditions among these will be illustrated and described.

Further, the controller 22 performs the first control before the blowing operation in which the fan 48 is driven by the fan motor 49 according to the establishment of the blowing start condition.

In this embodiment, the self-diagnosis condition corresponds to an example of the ventilation start condition. The self-diagnosis condition is a condition that triggers the execution of the self-diagnosis, and corresponds to an example of the device condition. The self-diagnosis includes a process of detecting an abnormality in the hot water supply system 1 (for example, an abnormality in driving the fan 48). Specifically, when a predetermined self-diagnosis condition is satisfied, the controller 22 drives the fan 48 for a certain period of time to perform a blowing operation, and the current, voltage, electric power, and temperature at a predetermined position within the fixed time. It operates to determine whether or not is within the normal range. For example, when the above self-diagnosis condition is satisfied, the controller 22 drives the fan motor 49 for a certain period of time, and supplies a current to a predetermined conductive path (for example, the fan motor 49) in the hot water supply system 1 at the fixed time. ) Can be determined, if it does not exceed the threshold value, it is determined to be a normal current, and if it exceeds the threshold value, it is determined to be an abnormal current. .. Alternatively, the controller 22 drives the fan motor 49 for a certain period of time when the above self-diagnosis condition is satisfied, determines that it is normal when the power consumption of the fan motor 49 does not exceed a certain value in this fixed time, and determines a constant value. A self-diagnosis may be performed so that an abnormality is determined when the value exceeds. The self-diagnosis condition can be, for example, "the combustion of the gas burner 4 is first started after a predetermined time (for example, 24 hours) has elapsed from the completion of the previous self-diagnosis". The self-diagnosis condition is not limited to this example, and another condition (for example, the combustion of the gas burner 4 has been performed a predetermined number of times since the previous self-diagnosis was completed, and a predetermined operation is performed on the hot water supply system 1). It may be that the combustion of the gas burner 4 is first started after the failure).

As shown in FIG. 2, the plurality of remote controllers 80 are arranged so as to be able to communicate with the controller 22 (detection unit, control unit, determination unit, drive unit). In the examples of FIGS. 1 and 2, as the plurality of remote controllers 80, a first remote controller 81 provided in the bathroom and a second remote controller 82 provided in a place different from the bathroom (for example, a kitchen or the like) are provided. ..

As shown in FIG. 2, the first remote controller 81 is provided with a control unit 81A configured as a known microcomputer or the like, a display unit 81B configured as a liquid crystal display device or the like, and a plurality of known switches such as a pressing button. It includes an operation unit 81C, a communication unit 81D that communicates with the controller 22 and the second remote controller 82, and an audio output unit 81E including a speaker that outputs audio. The operation unit 81C is composed of a plurality of operation units, and is used for an input operation for switching a power on / off state, an input operation for switching a set temperature, and the like.

The same applies to the second remote controller 82, which is provided with a control unit 82A configured as a known microcomputer or the like, a display unit 82B configured as a liquid crystal display device or the like, and a plurality of known switches such as a pressing button. It includes an operation unit 82C, a communication unit 82D for transmitting a signal or the like generated by the second remote controller 82 to the controller 22, and an audio output unit 82E including a speaker that outputs audio.

The second remote controller 82 has the same configuration as the first remote controller 81 or has a simplified configuration, and can be set in the same manner as the first remote controller 81. Both remote controllers 80 are designed so that the on / off states are interlocked with each other. In both remote controllers 80, the contents set on the one hand are reflected on each other.

(Hot water supply control)
The controller 22 controls the hot water supply according to the flow as shown in FIG. 3, for example. The controller 22 executes the hot water supply control of FIG. 3 after the power is turned on, and determines in S11 whether or not the combustion start condition is satisfied. The combustion start condition may be, for example, "the amount of water detected by the water amount sensor 34 (for example, the amount of water per unit time) (hereinafter, also simply referred to as" water amount ") is equal to or higher than a predetermined threshold value" or another. It may be the condition of. Until the combustion start condition is satisfied, the standby state is set, and the determination of No is repeated in S11.

When the controller 22 determines that the combustion start condition is satisfied (S11: Yes), the controller 22 executes the ignition process in S12. The controller 22 performs the following processing in the ignition processing (S12). The controller 22 operates an igniter (not shown) to discharge from the hot water supply spark plug 35. Further, the controller 22 opens the gas source solenoid valve 42 and the hot water supply switching solenoid valves 46, 46 ..., sets the hot water supply gas proportional control valve 44 to a slow ignition operation, and ignites the gas burner 4. After that, the controller 22 determines whether or not the combustion of the gas burner 4 is detected by the hot water supply frame rod 36, and if it is determined that the combustion is detected, terminates the slow ignition operation and performs the ignition process (S12). finish.

After the ignition process (S12) is completed, the controller 22 determines whether or not the combustion end condition is satisfied in S13. The combustion end condition may be, for example, "the amount of water detected by the water amount sensor 34 (for example, the amount of water per unit time) is less than a predetermined threshold value", or another condition (combustion with respect to the hot water supply system 1). It may be that a predetermined operation for instructing the end of combustion has been performed, a predetermined stop condition has been satisfied as a condition for stopping combustion, and the like). When the controller 22 determines that the combustion end condition is not satisfied (S13: No), the controller 22 determines whether or not the change condition is satisfied in S14. The change conditions are, for example, "the entry temperature detected by the thermistor 25 (hereinafter, also simply referred to as" entry temperature "), the set temperature set by the remote controller 80 (hereinafter, simply referred to as" set temperature "), and the water volume sensor. It may be that at least one of the water amounts detected by 34 (for example, the water amount per unit time) has been changed to meet a predetermined criterion, or it may be another condition.

When the controller 22 determines that the change condition is not satisfied (S14: No), the controller 22 performs feedback temperature control in S15. The controller 22 is based on the temperature difference between the hot water outlet temperature (hereinafter, also referred to as “hot water temperature”) detected by the thermistor 26 and the set temperature in the feedback temperature control, and the output required to reduce the temperature difference (hereinafter, also referred to as “hot water temperature”). Combustion output) is calculated, and the rotation speed of the fan 48 and the opening degree of the hot water supply gas proportional control valve 44 are adjusted. Further, when it is necessary to further increase or decrease the output, the controller 22 switches between the four stages of combustion stages by switching the opening and closing of each of the hot water supply switching solenoid valves 46, 46. When the feedback temperature control (S15) is completed, the controller 22 returns to the process of S13. That is, the controller 22 repeatedly executes the feedback temperature control (S15) until the combustion end condition is satisfied or the change condition is satisfied.

When the controller 22 determines that the change condition is satisfied (S14: Yes), the controller 22 controls the feedforward temperature in S16. In the feedforward temperature control, the controller 22 calculates the required combustion output (output) based on the temperature difference between the incoming water temperature and the set temperature and the amount of water. Then, the controller 22 sets the combustion stage corresponding to the calculated output, and adjusts the rotation speed of the fan 48 and the opening degree of the hot water supply gas proportional control valve 44. When the feedforward temperature control (S16) is completed, the controller 22 returns to the process of S13.

When the controller 22 determines that the combustion end condition is satisfied (S13: Yes), the self-diagnosis condition (for example, "after a predetermined time (for example, 24 hours) has elapsed from the completion of the previous self-diagnosis) in S17, It is determined whether or not the condition (condition that the combustion of the gas burner 4 is started first) is satisfied.

When the controller 22 determines that the self-diagnosis condition is satisfied in S17 (S17: Yes), the controller 22 executes the first control described above in S20. Specifically, the controller 22 opens the hot water supply switching solenoid valves 46, 46 ... While closing the gas source solenoid valve 42 in S20. In other words, the controller 22 switches the gas source solenoid valve 42 to the closed state while keeping the hot water supply switching solenoid valves 46, 46 ... In the open state. When a part of the hot water supply switching solenoid valves 46, 46 ... Is in the open state and the rest is in the closed state, the controller 22 keeps the open state in the open state and is in the closed state. Those that have been closed will remain blocked.

The controller 22 performs the first determination process described above in S21 during the first control (S20). That is, the controller 22 determines whether or not the combustion in the gas burner 4 is detected based on the signal from the hot water supply frame rod 36. When the controller 22 determines that the combustion in the gas burner 4 is detected (S21: Yes), the controller 22 determines that the gas source solenoid valve 42 is abnormal, and for example, the display unit 82B, the voice output unit 82E, or the like informs the user. Notify the occurrence of an abnormality. The controller 22 ends the first determination process (S21) after notifying the occurrence of an abnormality or when it is determined that combustion in the gas burner 4 has not been detected.

After the first determination process (S21), the controller 22 closes the gas source solenoid valve 42 and the hot water supply switching solenoid valves 46, 46 ... In S22. That is, the controller 22 switches all the hot water supply switching solenoid valves 46, 46 ... To the closed state while keeping the gas source solenoid valve 42 in the closed state.

The controller 22 performs the above-mentioned self-diagnosis in S23 after closing the gas source solenoid valve 42 and the hot water supply switching solenoid valves 46, 46. That is, the controller 22 drives the fan 48 for a certain period of time to perform an air blowing operation, and determines whether or not the current, voltage, electric power, temperature, etc. at a predetermined position are within the normal range within the fixed time. Operate. After that, the controller 22 returns to S11.

When the controller 22 determines in S17 that the self-diagnosis condition is not satisfied (S17: No), the controller 22 performs the second control described above in S30. That is, the controller 22 opens the gas source solenoid valve 42 while closing all the hot water supply switching solenoid valves 46, 46 ... In S30. In other words, the controller 22 switches the hot water supply switching solenoid valves 46, 46 ... Which are in the open state to the closed state while keeping the gas source solenoid valve 42 in the open state.

The controller 22 performs the second determination process described above in S31 during the second control (S30). That is, the controller 22 determines whether or not the combustion in the gas burner 4 is detected based on the signal from the hot water supply frame rod 36. When the controller 22 determines that the combustion in the gas burner 4 is detected (S31: Yes), the controller 22 determines that the gas source solenoid valve 42 is abnormal, and for example, the display unit 82B, the voice output unit 82E, or the like informs the user. Notify the occurrence of an abnormality. The controller 22 ends the second determination process (S31) after notifying the occurrence of an abnormality or when it is determined that combustion in the gas burner 4 has not been detected.

After the second determination process (S31), the controller 22 closes the gas source solenoid valve 42 and the hot water supply switching solenoid valves 46, 46 ... In S32. That is, the controller 22 switches the gas source solenoid valve 42 to the closed state while maintaining the hot water supply switching solenoid valves 46, 46 ... In the closed state. After that, the controller 22 returns to S11.

The following description relates to an example of the effect of this configuration.
The hot water supply system 1 can detect the presence or absence of an abnormality in the gas source solenoid valve 42 by performing the first determination process, and the presence or absence of an abnormality in the hot water supply switching solenoid valves 46, 46 ... By performing the second determination process. Can be detected.

However, in the hot water supply system 1, when the first control is performed, the hot water supply switching solenoid valves 46, 46 ... Are left in the open state, so that even after the gas source solenoid valve 42 is closed, the gas source solenoid valve 42 is closed. Combustion in the gas burner 4 is continued until the combustion of the gas remaining on the downstream side of the valve 42 is completed. Therefore, in this hot water supply system 1, when the first control is performed, excess heat is likely to be applied to the inside of the water pipe, and the heated water is likely to remain in the water pipe. Then, when the next combustion start condition is satisfied with the heated water remaining in the water passage pipe, the temperature of the heated residual water is detected as the hot water discharge temperature, and the feedback temperature control is performed based on this hot water discharge temperature. In this case, it may take time to bring the hot water temperature close to the set temperature.

However, this hot water supply system 1 performs the first control before the blowing operation. Therefore, even if the heated water remains inside the water pipe due to the first control, the water temperature of the water remaining in the water pipe is lowered by the blowing operation by the fan 48. Therefore, even if the heated water remains inside the water pipe due to the first control, the hot water supply system 1 lowers the temperature of the heated residual water before performing the next combustion. be able to.

In particular, the hot water supply system 1 performs the first control according to the time when the self-diagnosis accompanied by the blowing operation is performed. Therefore, in this hot water supply system 1, the next time the heated water remains inside the water pipe, as compared with the configuration in which the water temperature of the water superheated by the first control is lowered by separately blowing the air. It is possible to efficiently suppress the occurrence of a situation in which combustion occurs.

<Other embodiments>
The present disclosure is not limited to the embodiments described above with reference to the description and drawings. For example, the features of the embodiments described above or below can be combined in any combination within a consistent range. Further, any of the features of the above-mentioned or later-described embodiments may be omitted unless it is clearly stated as essential. Further, the above-described embodiment may be modified as follows.

In the above-described embodiment, the detection unit is the hot water supply frame rod 36, but another configuration may be used as long as it can detect the combustion of the gas burner 4. For example, the detection unit may detect any of the heat, light, and electrical characteristics of the combustion flame. As a specific example, the hot water supply system 1 may be configured to include a thermocouple for detecting the combustion heat of the gas burner 4, and this thermocouple may be used as a detection unit. As yet another example, the hot water supply system 1 may be configured to include an optical sensor classified into, for example, three types (ultraviolet type, visible light type, and infrared type) according to the wavelength to be detected, and this optical sensor may be used as a detection unit.

In the above-described embodiment, the predetermined device conditions are set as the self-diagnosis conditions, but other conditions may be used. For example, it may be a device condition that the number of executions of a predetermined device (for example, a fan, a gas burner, etc.) has reached a certain value since the completion of the previous first control, and the predetermined device has been determined since the completion of the previous first control. It may be a device condition that the cumulative execution time of the device reaches a certain value. Further, the hot water supply system 1 may set time conditions instead of equipment conditions. The time condition may be, for example, "after a predetermined time when the frequency of use of the hot water supply system 1 is reduced". Alternatively, the time condition may be "a certain time has passed since the completion of the previous first control". Further, the hot water supply system 1 may be configured to set both the equipment condition and the time condition and perform the first control when either condition is satisfied.

In the above-described embodiment, the blowing operation performed after the first control is defined as the “blowing operation at the time of self-diagnosis”, but it does not have to be the blowing operation at the time of self-diagnosis.

It should be noted that the embodiments disclosed this time are exemplary in all respects and are not restrictive. The scope of the present invention is not limited to the embodiments disclosed here, but includes all modifications within the scope indicated by the claims or within the scope equivalent to the claims. Is intended.

1 ... Hot water supply system 4 ... Gas burner (burner)
6 ... Hot water supply side heat exchanger (heat exchanger)
7a, 8a ... Heat transfer tube (water pipe)
10 ... Hot water pipe (water pipe)
12 ... Water inlet pipe (water pipe)
20 ... Piping (water pipe)
22 ... Controller (control unit, detection unit, judgment unit, drive unit)
36 ... Hot water supply frame rod (detector)
40 ... Gas flow path 42 ... Gas source solenoid valve (first solenoid valve)
46 ... Hot water supply switching solenoid valve (second solenoid valve)
48 ... Fan (blower)
49 ... Fan motor (drive unit)

Claims (3)

A water pipe that allows water introduced from the outside to pass through,
A burner that burns combustion gas to generate exhaust gas,
A gas flow path that supplies the combustion gas to the burner, and a gas flow path.
A first solenoid valve that switches between an open state in which the gas flow path is open and a closed state in which the gas flow path is closed,
A second solenoid valve that switches between an open state in which the gas flow path is open and a closed state in which the gas flow path is closed at a position downstream of the first solenoid valve.
A heat exchanger provided in the middle of the water pipe and transmitting the heat of the exhaust gas to the water passing through the inside of the water pipe.
The first control that opens the second solenoid valve while closing the first solenoid valve when the combustion end condition is satisfied, and the closed state of the second solenoid valve when the combustion end condition is satisfied. A control unit that performs a second control that opens the first solenoid valve, and a control unit that performs the second control.
A detector that detects combustion in the burner and
During the first control, the detection unit determines whether or not combustion in the burner is detected, and during the second control, the detection unit detects combustion in the burner. A determination unit that performs a second determination process to determine whether or not it is
Equipped with
The control unit is a hot water supply system that performs the first control when the predetermined time condition or the equipment condition is satisfied when the combustion end condition is satisfied, and performs the second control when the condition is not satisfied. A blower that blows air into the heat exchanger,
A drive unit that starts driving the blower when the blower start condition is satisfied and stops the drive of the blower when the blower stop condition is satisfied.
Equipped with
The hot water supply system according to claim 1, wherein the control unit performs the first control before the blower operation in which the drive unit drives the blower according to the establishment of the blower start condition. The drive unit drives the blower when the self-diagnosis condition is satisfied.
The hot water supply system according to claim 2, wherein the control unit performs the first control before the blowing operation according to the establishment of the self-diagnosis condition.

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