JP6079403B2 - Hot water supply apparatus and method for controlling hot water supply apparatus - Google Patents

Description

  The present invention relates to a safe operation of a hot water supply apparatus when a high temperature hot water discharge abnormality occurs.

  As this type of hot water supply apparatus, there is a structure in which a water inlet path and a hot water outlet path are respectively connected to a heater, and a flow rate adjustment valve is provided on the side of the hot water outlet. In such a hot water supply apparatus, normally, when an abnormality occurs during a hot water supply operation, a safety operation is performed to prevent hot water unintended by the user from being discharged.

  For example, Japanese Patent Laid-Open No. 10-73315 (Patent Document 1) discloses that the flow rate adjustment valve is fully closed as a safe operation when a high temperature hot water discharge abnormality occurs in which hot water having a temperature higher than a desired temperature is discharged. The hot water supply apparatus comprised by this is disclosed. When a hot water supply abnormality is detected during a hot water supply operation and the hot water supply operation is stopped by a safe operation, the hot water supply path leading to the hot water tap is filled with hot water. In Patent Document 1, when a high temperature hot water supply abnormality is detected, the flow rate adjustment valve is fully closed to prevent high temperature hot water from flowing out even if the user unintentionally opens the hot water tap.

JP-A-10-73315

  However, in the hot water supply apparatus described in Patent Document 1 described above, the following problems may occur. In spite of the safe operation, the user turns off the operation switch for selecting operation / stop of the hot water supply device, and turns it on again, so that the error of the hot water supply device is canceled and the hot water supply device is initialized. Thereby, since the opening degree of the flow rate adjusting valve is also set to the initial opening degree, when the user carelessly opens the hot water tap thereafter, the hot water remaining in the hot water discharge pipe may flow out.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a hot water supply device that can reliably prevent unintended high temperature hot water from being discharged when a high temperature hot water abnormality occurs. Is to provide.

  A hot water supply apparatus according to the present invention is a hot water supply apparatus that heats hot water with a heat source machine, a heat exchanger that exchanges heat with the amount of heat generated by the heat source machine, and a water inlet and a hot water source connected to the heat exchanger. A flow rate adjusting valve for adjusting the flow rate of the hot water flowing out from the hot water outlet, and a control unit for controlling the opening degree of the flow rate adjusting valve. The control unit stops the heat source when the temperature of the hot water exceeding the predetermined allowable upper limit temperature is detected, fully closes the flow rate adjustment valve, and fully closes the flow rate adjustment valve. The flow rate adjustment valve is opened with the upper limit of the opening at which hot water having a predetermined flow rate that is smaller than the flow rate at the time of detecting abnormal hot water is discharged.

  In the above hot water supply apparatus, as a safe operation when a high temperature hot water discharge abnormality occurs, the flow rate adjustment valve is once closed and then the flow rate adjustment valve is opened while restricting the flow rate more than when a high temperature hot water discharge abnormality is detected. Thereby, in the state where the hot-water tap is opened, the hot water remaining in the hot water outlet is discharged in a state where the flow rate is limited. As a result, unintended high temperature hot water can be reliably prevented from coming out.

  Preferably, the control unit fully closes the flow rate adjustment valve by reducing the opening degree of the flow rate adjustment valve until the opening degree at which the shutoff of the hot water outlet is guaranteed.

  According to this, even when there is a variation in the flow rate characteristics of the flow rate adjusting valve, the flow rate adjusting valve can be reliably closed, so that the hot water outlet can be blocked.

  Preferably, the control unit increases the opening degree of the flow rate adjustment valve until the opening degree at which a predetermined flow rate of hot water is discharged is monitored while monitoring the flow rate of the hot water flowing out from the hot water outlet.

  According to this, the flow rate of the hot water flowing out from the hot water outlet can be kept within the predetermined flow rate regardless of variations in the flow rate characteristics of the flow rate adjusting valve.

  Preferably, the control unit prohibits initialization of the hot water supply apparatus until a predetermined time elapses after the detection of the high temperature hot water abnormality.

  According to this, it can prevent that the restriction | limiting to the opening degree of a flow regulating valve remove | deviates by initializing a hot-water supply apparatus after detection of high temperature hot-water supply abnormality.

  More preferably, the hot water supply device is configured to be able to be initialized in response to an input operation to the operation unit, and the control unit inputs the operation unit until a predetermined time elapses after a high temperature hot water abnormality is detected. It cannot be accepted.

  According to this, it can prevent reliably that the hot water supply apparatus is initialized by a user's input operation.

  As described above, according to the present invention, high temperature hot water can be reliably prevented from being discharged when a high temperature hot water abnormality occurs.

1 is an overall configuration diagram of a hot water supply device according to an embodiment of the present invention. It is the flowchart which showed the control processing procedure for implement | achieving safe operation | movement in the hot water supply apparatus according to embodiment of this invention. It is a figure which shows the flow volume characteristic of an excessive outflow servo valve. 3 is a flowchart for explaining the process of step S04 in FIG. 2 in more detail.

  Embodiments of the present invention will be described in detail with reference to the drawings. Note that the same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated.

[Configuration of water heater]
FIG. 1 is an overall configuration diagram of a hot water supply apparatus according to an embodiment of the present invention.

  Referring to FIG. 1, hot water supply apparatus 100 includes a combustion unit 4 that burns fuel gas to generate combustion gas, a primary heat exchanger 2, a secondary heat exchanger 3, and a blower 5. The combustion unit 4, the primary heat exchanger 2, the secondary heat exchanger 3, and the blower 5 are provided in the can 1.

  The combustion unit 4 includes a burner 40 that burns fuel gas as fuel, and a combustion space 44. The burner 40 is provided with an electromagnetic valve 42, and the supply of fuel to the burner 40 can be restricted. The combustion space 44 is a space in which a flame is formed by combustion in the burner 40, and is also a portion where combustion gas generated by combustion is generated. The blower 5 is provided in the inner lower part (upstream side in the air flow direction) of the can 1 and blows air mainly mixed with fuel gas. Although not shown, a gas proportional valve and an original gas solenoid valve are arranged upstream of the solenoid valve 42 in the fuel flow direction.

  The primary heat exchanger 2 and the secondary heat exchanger 3 exchange heat with the fuel gas generated by the combustion unit 4. Specifically, the primary heat exchanger 2 mainly recovers sensible heat of the combustion gas. The primary heat exchanger 2 has a heat receiving pipe 20 through which hot water flows and fins 22 attached to the outside of the heat receiving pipe 20, and is a so-called fin-and-tube heat exchanger made of copper. The primary heat exchanger 2 recovers sensible heat of the combustion gas and heats hot water flowing through the heat receiving pipe 20.

  The primary heat exchanger 2 has a water inlet 24 through which hot water is introduced into the heat receiving pipe 20 and a water outlet 26 through which hot water that has passed through the heat receiving pipe 20 is discharged. Specifically, in the can 1, when hot water that has passed through the secondary heat exchanger 3 described later is introduced into the primary heat exchanger 2 from the water inlet 24, the hot water is heated by the primary heat exchanger 2. Thereafter, the water is supplied to the hot water tap 8 such as a curan through the water outlet 26. That is, the primary heat exchanger 2 is located downstream of the secondary heat exchanger 3 in the hot water flow direction.

  The secondary heat exchanger 3 is located downstream of the primary heat exchanger 2 in the flow direction of the combustion gas (upper side in FIG. 1), and recovers the latent heat of the combustion gas. The secondary heat exchanger 3 has a heat receiving pipe 34 formed of a bare stainless steel pipe. That is, the latent heat recovery type secondary heat exchanger 3 is formed of a material that is more excellent in corrosion resistance than the sensible heat recovery type primary heat exchanger 2. Further, in the secondary heat exchanger 3, since the water vapor contained in the combustion gas is condensed and liquefied drain is generated by heat exchange, a drain discharge system (not shown) for guiding the drain to the outside is provided. Yes.

  The hot water supply device 100 includes a water supply pipe 6 connected to the secondary heat exchanger 3, a hot water pipe 7 connected to the primary heat exchanger 2, and primary heat exchange between the secondary heat exchanger 3 and the hot water pipe 7. And a bypass pipe 28 for bypassing the vessel 2. The water supply pipe 6 communicates with a water supply source such as a water pipe (not shown) and constitutes a water intake channel that receives supply of tap water or the like. The hot water discharge pipe 7 communicates with a hot water tap 8 such as a currant for use of hot water supply, and constitutes a hot water outlet for discharging hot water heated by the heat exchangers 2 and 3.

  The water supply pipe 6 is provided with an incoming water temperature sensor 62 for detecting the incoming water temperature and an incoming water amount sensor 64 for detecting the incoming water amount to the hot water supply device 100. The hot water discharge pipe 7 is provided with an overflow servo valve 70 and a hot water temperature sensor 72 that detects the temperature of the hot water from the hot water supply device 100.

  The excessive outflow servo valve 70 is provided on the downstream side from the junction of the hot water pipe 7 and the bypass pipe 28. The excess spill servo valve 70 is a flow rate adjustment valve for adjusting the amount of hot water discharged when the amount of water flow to the heat exchangers 2 and 3 exceeds the maximum heating capacity. Function. The excessive outflow servo valve 70 is, for example, an electric expansion valve configured to adjust the opening degree by a stepping motor. The opening degree of the excessive outflow servo valve 70 is controlled by driving the stepping motor by the control unit 10 described later. Note that. Instead of the configuration shown in FIG. 1, an overflow servo valve 70 may be provided in the water supply pipe 6.

  The hot water temperature sensor 72 is provided downstream from the joining point of the hot water pipe 7 and the bypass pipe 28, and the hot water heated by the heat exchangers 2 and 3 and the hot water that has passed through the bypass pipe 28 are mixed. Detect the tapping temperature.

  The hot water supply apparatus 100 is provided with a control unit 10 for controlling the hot water supply operation. The control unit 10 includes a microcomputer, a memory, a timer, and the like (not shown). The hot water supply operation is controlled when the control unit 10 causes the microcomputer to execute a control program for the hot water supply device 100 stored in the memory. Specifically, the control unit 10 controls the opening degrees of the electromagnetic valve 42, the excessive outflow servo valve 70, and the like based on the detection values of the various sensors 62, 64, 72, and the like.

  A remote controller 110 for remotely operating the hot water supply device 100 is connected to the control unit 10. Control unit 10 is configured to be capable of bidirectional communication with remote controller 110. The remote controller 110 is provided with an operation switch, a touch panel, and the like (not shown). On the touch panel, an operation screen for inputting and setting a hot water supply set temperature or the like is displayed by performing a touch operation on the screen. The operation switch is a switch for selecting operation / stop of the hot water supply apparatus 100. When the operation switch is turned “ON”, the hot water supply apparatus 100 is activated, and when the operation switch is turned “OFF”, the operation of the hot water supply apparatus 100 is stopped. When the hot water tap 8 such as a currant is operated with the operation switch turned on, a hot water supply operation is executed. The hot water supply operation is an operation mode in which water supplied from a water supply source (not shown) is heated by the primary heat exchanger 2 and the secondary heat exchanger 3 and discharged.

  Control unit 10 further detects whether or not an abnormality has occurred in hot water supply apparatus 100 and the content of the abnormality during execution of the hot water supply operation. And when abnormality arises, the control part 10 performs the safe operation | movement for preventing hot hot water from flowing out when a user does not intend.

  Here, as abnormality of hot water supply apparatus 100, when combustion in combustion part 4 is not detected, or when afterfire abnormality is detected, hot water supply temperature is higher than an upper limit value (allowable upper limit temperature) of a preset allowable range. There is a case where the hot water becomes hot or a low temperature hot water where the hot water supply temperature is lower than the lower limit value (allowable lower limit temperature) of the allowable range. Among these, when a high temperature hot water abnormality occurs, hot water unintended by the user may be discharged. Therefore, it is necessary to forcibly stop the hot water supply operation when a high temperature hot water discharge abnormality is detected.

  Hereinafter, the safe operation of the hot water supply apparatus 100 when a high temperature hot water discharge abnormality occurs will be described.

  FIG. 2 is a flowchart showing a control processing procedure for realizing a safe operation in hot water supply apparatus 100 according to the embodiment of the present invention. The flowchart shown in FIG. 2 is realized by a program stored in advance in the control unit 10 being called from the main routine when the hot water supply operation is being executed and executed in a predetermined cycle.

  Referring to FIG. 2, control unit 10 first diagnoses whether or not there is an abnormality in high-temperature hot water at step S01. Specifically, control unit 10 monitors the temperature of hot water from hot water supply apparatus 100 during execution of the hot water supply operation based on the detection value of hot water temperature sensor 72. The controller 10 determines whether or not the hot water temperature is within a preset allowable range. Then, when the state where the hot water temperature exceeds the allowable upper limit temperature continues for a predetermined time, the control unit 10 diagnoses a high temperature hot water abnormality (YES in step S01). On the other hand, when the hot water temperature is within the allowable range, control unit 10 does not diagnose the hot hot water abnormality (NO in step S01), and ends the process.

  If it is diagnosed in step S01 that there is an abnormality in high temperature hot water, the control unit 10 forcibly stops the hot water supply operation. Specifically, the control unit 10 stops the combustion in the combustion unit 4 in step S02. For example, the control unit 10 shuts off the supply of fuel gas to the burner 40 by fully closing the electromagnetic valve 42.

  In step S03, the control unit 10 starts measuring the elapsed time after the detection of the high temperature hot water abnormality using a timer or the like.

  In step S04, the control unit 10 controls the opening degree of the overflow servo valve 70 for closing the overflow servo valve 70. The opening degree control of the overflow servo valve 70 will be described later in detail.

  In step S05, the control unit 10 determines whether or not the elapsed time after the detection of the high temperature hot water abnormality has reached a predetermined time. The predetermined time corresponds to the time necessary for the temperature of hot water remaining in the hot water outlet to fall within an allowable range. This predetermined time may be a fixed time (for example, about 1 minute), or may be a time that is variably set according to the hot water temperature when a hot hot water abnormality is detected.

  When the elapsed time since the detection of the hot hot water abnormality has not reached the predetermined time (NO in step S05), control unit 10 prohibits the error from being canceled in step S06. Specifically, the control unit 10 puts the remote controller 110 into a locked state where it does not accept input operation of the operation switch.

  Generally, the hot water supply apparatus 100 is configured such that, when an error occurs, the user turns off the operation switch of the remote controller 110 and turns it on again to release the error and initialize the hot water supply apparatus 100. . Therefore, if the user turns the operation switch OFF and ON immediately after the occurrence of the high temperature hot water abnormality, the opening degree of the overflow servo valve 70 returns from the fully closed state to the initial opening degree due to the initialization of the hot water supply device 100. If the user carelessly opens the hot-water tap 8, hot water remaining in the hot water outlet may be discharged. Therefore, control unit 10 prohibits initialization of hot water supply device 100 by prohibiting error cancellation within a predetermined time after detection of a high temperature hot water supply abnormality.

  When the elapsed time after the detection of the high temperature hot water abnormality has reached a predetermined time (YES in step S05), control unit 10 can cancel the error by turning off the operation switch of remote controller 110 in step S07. State. Thereby, the locked state of the operation switch of the remote controller is released.

[Opening control of overflow servo valve]
The opening degree control of the excessive outflow servo valve 70 in step S04 in FIG. 2 will be described below.

  FIG. 3 is a diagram showing the flow rate characteristics of the excessive outflow servo valve 70. The horizontal axis in FIG. 3 indicates the control amount of the excessive outflow servo valve 70, and the vertical axis in FIG. 3 indicates the flow rate (hot water amount) per unit time of the hot water discharged from the hot water supply device 100. This amount of hot water corresponds to the detected value of the incoming water amount sensor 64 (FIG. 1).

  When the overflow servo valve 70 is an electric expansion valve using a stepping motor, the amount of change in the opening degree of the overflow servo valve 70 is the number of steps in the stepping motor (that is, a pulse for exciting each phase winding of the stator). Number of signals). The absolute opening degree of the overflow servo valve 70 (difference from the reference opening degree such as full closing or full opening) is calculated by accumulating the amount of change (number of steps) every time the opening degree is changed.

  Referring to FIG. 3, when the number of steps in the stepping motor is increased, the flow rate is reduced by decreasing the opening degree of overflow servo valve 70. Note that in a region where the control amount is greater than a certain number of steps, the amount of change in the flow rate with respect to the amount of change in the control amount is larger than in a region where the control amount is smaller than the number of steps. That is, the flow characteristic of the excessive outflow servo valve 70 has an inflection point.

  FIG. 3 shows three relationships with different flow rates for the same control amount (number of steps). In the following description, a relationship indicated by a black circle in the figure is referred to as “relation 1”, a relationship indicated by a black square in the figure is referred to as “relation 2”, and a relationship indicated by a black triangle in the figure is referred to as “relationship”. Also referred to as “3”. Comparing these three relationships, the flow rate for the same number of steps is the smallest in relationship 1 and the largest in relationship 3. Therefore, the relationship 1 is the smallest and the relationship 3 is the largest as the number of steps when the overflow servo valve 70 is fully closed, that is, when the flow rate becomes almost zero.

  The reason why the relationship between the control amount and the flow rate of the overflow servo valve 70 varies as described above includes the manufacturing variation of the overflow servo valve 70 and the variation in the water pressure of the water supplied from the water supply source. For this reason, in the conventional hot water supply apparatus, when the occurrence of a high temperature hot water abnormality is detected, even if the flow characteristics of the overflow servo valve 70 vary, the overflow servo valve 70 can be reliably closed. By driving the stepping motor at full speed, the overflow servo valve 70 is fully closed at full speed. For example, when the overflow servo valve 70 has a variation in flow characteristics as shown in FIG. 3, the overflow servo valve 70 is reliably set by setting the control amount (number of steps) of the overflow servo valve 70 to about 2700 steps. Can be closed.

  However, if the overflow servo valve 70 is closed as described above, high-temperature hot water remains in the hot water outlet. Therefore, if the error is canceled by turning the operation switch OFF and ON after the detection of the high-temperature hot water abnormality, hot water may flow out when the hot-water tap 8 is open.

  Therefore, in the present embodiment, when a high temperature hot water discharge abnormality is detected, the combustion of the combustion section 4 is stopped, and the opening degree of the excessive outflow servo valve 70 is controlled as follows, so that Prevents hot water from remaining.

  As such an opening degree control of the overflow servo valve 70, a method of constricting the opening degree of the overflow servo valve 70 to such an extent that it does not reach full closing can be considered. For example, by controlling the opening degree so that the opening degree of the overflow servo valve 70 is reduced to 1900 steps, hot water remaining in the tapping path is discharged at a low flow rate.

  However, as shown in FIG. 3, since the flow characteristics of the overflow servo valve 70 vary, even if the opening degree of the overflow servo valve 70 is reduced to 1900 steps, the flow rate is actually limited to 8.0 L / min. The case where it cannot be squeezed occurs. On the contrary, the excessive outflow servo valve 70 may be fully closed by reducing the opening degree to 1900 steps.

  Therefore, instead of the control method of restricting the opening degree of the excessive outflow servo valve 70 to the predetermined step, the amount of hot water discharged is monitored at a predetermined flow rate while monitoring the amount of hot water discharged from the hot water supply device 100 using the detected value of the water incoming amount sensor 64. A method of controlling the opening degree of the excessive outflow servo valve 70 is considered.

  Thus, by restricting the opening degree of the excessive outflow servo valve 70 while monitoring the amount of discharged hot water, it is possible to suppress the influence of variation in the flow characteristics of the excessive outflow servo valve 70. However, as shown in FIG. 3, since the flow characteristic of the overflow servo valve 70 has an inflection point, the opening degree of the overflow servo valve 70 exceeds the inflection point by driving the stepping motor at full speed. It may happen that it is fully closed. On the other hand, if the driving speed of the stepping motor is reduced, hot water may flow out of the hot water supply channel before the opening degree of the excessive outflow servo valve 70 is reduced. As a result, it is necessary to finely adjust the driving speed of the stepping motor, and the opening degree control of the overflow servo valve 70 becomes complicated.

  In view of these problems, in the opening control of the excessive outflow servo valve 70 according to the present embodiment, once an abnormal hot water discharge is detected, the opening of the overflow servo valve 70 is once throttled until it is fully closed. . Then, after the overflow servo valve 70 is closed, the overflow servo valve 70 is opened so as to limit (reduce) the amount of hot water from that at the time of detecting a high temperature hot water abnormality.

FIG. 4 is a flowchart for explaining the process of step S04 of FIG. 2 in more detail.
Referring to FIG. 4, in step S041, control unit 10 drives the stepping motor at full speed based on a control amount that can securely close overflow servo valve 70. As a result, the excessive outflow servo valve 70 is fully closed. For example, when the overflow servo valve 70 has a variation in flow characteristics as shown in FIG. 3, the control amount (number of steps) of the overflow servo valve 70 is set to 2400 steps. By closing the overflow servo valve 70 at full speed, hot water is prevented from being discharged.

  Next, in step S042, the control unit 10 monitors the amount of hot water discharged from the hot water supply device 100 based on the detection value of the incoming water amount sensor 64, and sets the opening at which a predetermined flow rate of hot water is discharged as an upper limit to the overflow servo valve 70. Gradually open the valve. This predetermined flow rate is set to a flow rate that is smaller than the amount of hot water discharged at the time of detecting a high temperature hot water abnormality, and does not hinder the user from touching the hot water. As an example, the predetermined flow rate is set to 2.0 L / min. In this way, by opening the overflow servo valve 70 from the fully closed state to the upper limit at which the predetermined flow rate of hot water is discharged, the hot hot water remaining in the hot water passage flows out from the hot water passage little by little.

  In addition, about the process of step S042, instead of the structure which opens the excessive outflow servo valve 70, monitoring the amount of hot water, it opens to the opening degree set beforehand based on the flow volume characteristic of the excessive outflow servo valve 70. It is good also as a structure.

  Here, if the user turns the operation switch OFF and ON during execution of the opening control of the overflow servo valve 70 in step S04, the hot water supply device 100 is initialized. The limit will be removed. Therefore, the initialization of the hot water supply apparatus 100 is prohibited by setting the operation switch of the remote controller 110 to the locked state within a predetermined time after the detection of the high temperature hot water abnormality by the processing of steps S05 to S07 in FIG. Thereby, it is possible to reliably prevent hot water having a flow rate exceeding the predetermined flow rate from being discharged.

  Thus, according to the hot water supply apparatus according to the embodiment of the present invention, when a high temperature hot water abnormality is detected, the heat source machine is stopped and the overflow servo valve is fully closed to shut off the high temperature hot water. . Then, the excessively flowing out servo valve is gradually opened to allow the hot water remaining in the hot water outlet to flow out at a predetermined flow rate that is smaller than the flow rate at the time of detecting high temperature hot water abnormality. Thereby, the outflow of the hot water which is not intended can be prevented reliably.

  Further, by prohibiting the initialization of the hot water supply device until a predetermined time has elapsed after the detection of the high temperature hot water abnormality, it is possible to reliably control the opening degree of the overflow servo valve.

  In this embodiment, the prohibition of initialization of the hot water supply apparatus within a predetermined time after the detection of the high-temperature hot water discharge abnormality has been described in connection with the opening control of the overflow servo valve in the present embodiment. It is also possible. For example, it is possible to prevent hot water from flowing out at the timing when the hot water supply device is initialized by setting the predetermined time assuming the time until the temperature of the hot water remaining in the hot water outlet enters an allowable range. it can.

  Moreover, in this Embodiment, although the combustion part 4 which consists of the burner 40 which burns fuel gas as a fuel was illustrated as a "heat source machine" which generate | occur | produces the calorie | heat amount for heating hot water, application of this invention is such The point which is not limited to a structure is described definitely. That is, any “heat source device” can be adopted as long as it is configured to control the amount of generated heat. For example, instead of the gas burner, an arbitrary heat source such as an oil burner for burning oil or a heat pump mechanism can be applied.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Can body, 2 Primary heat exchanger, 3 Secondary heat exchanger, 4 Combustion part, 5 Blower, 6 Water supply pipe, 7 Hot water outlet pipe, 8 Hot water tap, 10 Control part, 20, 34 Heat receiving pipe, 22 Fin, 24 Water inlet, 26 Water outlet, 28 Bypass pipe, 40 Burner, 42 Solenoid valve, 44 Combustion space, 62 Water inlet temperature sensor, 64 Water inlet volume sensor, 70 Overflow servo valve, 72 Hot water temperature sensor, 100 Hot water supply device, 110 Remote control .

Claims (6)

A hot water supply apparatus that heats hot water with a heat source machine,
A heat exchanger for exchanging heat with the amount of heat generated by the heat source unit;
A water inlet and a water outlet connected to the heat exchanger;
A flow rate adjusting valve for adjusting the flow rate of hot water flowing out of the hot water outlet;
A control unit for controlling the opening of the flow regulating valve,
The control unit stops the heat source unit, fully closes the flow rate adjustment valve, and fully closes the flow rate adjustment valve when a hot water discharge abnormality in which the temperature of the hot water exceeds a predetermined allowable upper limit temperature is detected. Then, the hot water supply apparatus opens the flow rate adjusting valve with an upper limit of an opening degree at which hot water having a predetermined flow rate smaller than the flow rate at the time of detecting the high temperature hot water abnormality is discharged.   The hot water supply device according to claim 1, wherein the control unit fully closes the flow rate adjustment valve by reducing an opening degree of the flow rate adjustment valve until an opening degree at which the shutoff of the hot water supply passage is guaranteed. .   The said control part increases the opening degree of the said flow rate adjustment valve until it becomes the opening degree by which the hot water of the said predetermined flow rate is poured out, monitoring the flow volume of the hot water which flows out out of the said tap line. Water heater.   The hot water supply apparatus according to any one of claims 1 to 3, wherein the control unit prohibits initialization of the hot water supply apparatus until a predetermined time elapses after the high temperature hot water discharge abnormality is detected. The hot water supply device is configured to be initialized in response to an input operation to the operation unit,
The hot water supply apparatus according to claim 4, wherein the control unit disables input of the operation unit until the predetermined time elapses after the high temperature hot water discharge abnormality is detected. A method for controlling a hot water supply apparatus for heating hot water with a heat source machine,
The water heater is
A heat exchanger for exchanging heat with the amount of heat generated by the heat source unit;
A water inlet and a water outlet connected to the heat exchanger;
A flow rate adjustment valve for adjusting the flow rate of hot water flowing out from the hot water outlet,
The control method is:
A step of shutting down the heat source device and fully closing the flow rate adjustment valve when a hot water discharge abnormality in which the hot water temperature exceeds a predetermined allowable upper limit temperature is detected;
And a step of opening the flow rate adjustment valve with an opening degree at which a predetermined flow rate of hot water smaller than the flow rate at the time of detecting an abnormality in the high temperature hot water being discharged is set as an upper limit after the flow rate adjustment valve is fully closed. Control method.

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