JPH04283356A - Controller for hot water supplying apparatus - Google Patents

Abstract

PURPOSE:To stabilize an output hot water temperature in a normal hot water supplying operation and to smoothly vary an output hot water temperature in a fluctuation for a massage. CONSTITUTION:In a controller having a feed water temperature thermistor 32, a feed water flow rate sensor 31, an output hot water temperature thermistor 33 and a feed hot water temperature set switch to control the quantity of heat of a main burner 2, a fluctuating function for varying the quantity of heat of the burner 2 in response to a time change so as to vary a temperature of hot water to be heated by a water heating circuit in response to a time change is provided. In a normal hot water supplying operation, a feedback control is executed based on sensing information of the thermistor 33. In the fluctuation, a control is not executed based on the sensing information of the thermistor 33.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a water heater having a fluctuating function for changing the temperature of hot water heated by a heat exchanger in accordance with changes in time.

0002

2. Description of the Related Art It is known that a massage effect can be obtained by changing the temperature of hot water heated by a water heater over time and using it for a shower. As one of the hot water supply controls for this purpose, for example,
In the invention of Publication No. 328, in a temperature control section that controls the hot water supply temperature, a signal from a signal generation section for temporally changing the set temperature is compared with a detection signal of the hot water supply temperature detected by a hot water outlet temperature detector. Perform PID control to amplify,
A temperature controller (fuel pressure controller) is driven by this PID control signal to obtain a hot water temperature corresponding to the signal from the signal generator.

0003

[Problem to be solved by the invention] However, the above PID
In normal hot water supply, which targets a constant temperature, the set temperature does not change, so accurate and stable hot water temperature can be obtained. The detection signal of the hot water supply temperature detected by the hot water outlet temperature detector has a time delay with respect to the set temperature. For this reason, the detection signal of the hot water temperature sensor is used as a PI for temperature control to obtain a massage effect.
When D control is used, the detection signal of the hot water temperature is compared with a new set temperature that has been changed over time by the signal generator, which results in harmful information for feedback control. There is a problem in that the hot water outlet temperature cannot be obtained in accordance with the time-varying temperature setting signal.

The present invention provides a control device for a water heater that has a hot water temperature changing function that changes the hot water temperature in accordance with time changes for the purpose of a shower massage effect, etc. The purpose of the present invention is to maintain the stability of the hot water and smoothly change the outlet temperature in accordance with a set temperature that changes over time.

[0005]

[Means for Solving the Problems] The present invention provides a water supply temperature detection means for detecting the inflow temperature of water flowing into a water heating circuit including a heat exchanger equipped with a heating source; A water supply flow rate detection means for detecting the water supply flow rate, a hot water outlet temperature detection means for detecting the outlet temperature of the water heated by the water heating circuit, and a target temperature setting means for setting the target temperature of the hot water heated by the water heating circuit. In the water heater control device that controls the heating source, the heating amount of the heating source is changed in accordance with time changes in order to change the temperature of hot water heated by the water heating circuit in accordance with time changes. It has a fluctuation operation function, and in normal hot water supply operation, performs feedback control based on at least the detection information of the hot water outlet temperature detection means, and in the fluctuation operation, does not perform control based on the detection information of the hot water outlet temperature detection means. as a technical means.

[0006]

[Operation] In the present invention, when the fluctuation operation is not performed, the heating amount of the heating source is feedback-controlled based on at least the outlet temperature and the target temperature. Therefore, when the hot water outlet temperature is different from the set temperature, the heating amount of the heating source is gradually corrected based on the detection information of the hot water outlet temperature detection means, so that the hot water outlet temperature and the target temperature become equal. On the other hand, when the fluctuation operation is performed, the heating amount of the heating source is not controlled based on the detection information of the hot water temperature detection means, and for example, the detection information of the water supply temperature detection means and the water supply flow rate detection means and the target temperature It is controlled based on the target temperature of the setting means. Therefore, the detection information of the outlet hot water temperature detection means, which is detected with a time delay with respect to the heating amount of the heating source that changes with time changes due to the fluctuation operation, does not affect the control of the heating source. The heating amount of the source can be changed only as necessary for the fluctuation operation depending on the time change. As a result, the heating source performs a smooth fluctuation operation, and the temperature of the water heated by the water heating circuit changes with good responsiveness over time.

[0007]

According to the present invention, in the fluctuating operation, the information on the hot water temperature is not used to control the heating amount of the heating source, so that the fluctuating operation is performed smoothly. In this fluctuating operation, the heating amount of the heating source changes constantly, so even if the hot water temperature is slightly different from the target temperature change in the fluctuating operation, there is almost no problem considering the purpose. Since the temperature can be changed, the hot water temperature can be changed suitable for massage showers, etc.

[0008]

EXAMPLES Next, the present invention will be explained based on examples. The gas automatic water heater 1 shown in FIG. 2 is a fully automatic water heater that has a normal hot water supply function, an automatic hot water filling function for a bathtub B, an additional heating function, and a heat retention function. A main heat exchanger 11 for tensioning, a bath heat exchanger 12 for reheating, several piping members and piping members for connecting these heat exchangers 11 and 12 to the bathtub B. Several control members, a main burner 2 for heating each heat exchanger 11, 12, a bath burner 3, each burner 2
, gas supply pipe 4 that supplies fuel gas to 3;
It consists of several control valve members for gas control.

Water supply pipe 13 that supplies water to the main heat exchanger 11
is connected to the outflow part of the main heat exchanger 11 by a water bypass pipe 14, and the outlet pipe 15 is downstream thereof. The water supply pipe 13 is equipped with a water supply flow rate sensor 31 for detecting the flow rate of supplied water and a supply water temperature thermistor 32 for detecting the temperature of the supplied water. A hot water quantity servo 16 and a hot water outlet temperature thermistor 33 for detecting hot water temperature are provided, and the hot water outlet pipe 15 branches into a hot water supply pipe 17 and a hot water filling connection pipe 18 downstream of the hot water outlet temperature thermistor 33. Note that the water bypass pipe 14 is equipped with a water bypass electromagnetic valve 19 (hereinafter referred to as a water bypass valve) that is opened and closed depending on the operating state.

The hot water filling connection pipe 18 includes a hot water filling electromagnetic valve (hereinafter referred to as a hot water filling valve) 20 for controlling hot water filling, a hot water filling flow rate sensor 34 for detecting the hot water filling flow rate, and a hot water filling flow rate sensor 34 for detecting hot water filling flow rate. A backflow prevention device 21 with a hopper and a first two-way valve 22 are provided in order to prevent backflow when the pressure decreases, and the hot water filling connection pipe 18 is connected to the bath circulation circuit 23 downstream of the first two-way valve 22. It is connected. The backflow prevention device 21 is
Two check valves 21a and 21b are arranged in a double manner with respect to the hot water filling connection pipe 18, and an opening is provided between the check valves 21a and 21b that is reversibly opened and closed with the opening and closing of the upstream check valve 21a. 21c, and a hopper 21d is provided on the outside of the opening 21c for storing a small amount of hot water that flows out from the opening 21c when the check valve 21a is opened and closed.
In order to discharge hot water accumulated in the tank 1d, a drain electromagnetic valve 21e is provided which is opened when filling the water is finished.

The bath circulation circuit 23 forms a closed circuit between the bathtub B and the bath heat exchanger 12.
8, the first pipe line 23A connects the connection part 23a with the bath heat exchanger 12, and the second pipe line 23 connects the connection part 23a with the bathtub B.
B. Third pipe line 23 directly connecting the bath heat exchanger 12 and the bathtub
C, and the first pipe line 23A has a pipe that operates when circulating the hot water in the bathtub B and when determining the presence or absence of hot water in the bathtub B to direct the hot water in the bathtub B to the bath heat exchanger 12. a pump 24 for circulation, a water flow switch 35 for detecting the flow of hot water in the bath circulation circuit 23, and a bathtub B.
A bath thermistor 36 is provided to detect the temperature of the water inside the bath.
The second pipe line 23B is equipped with a second two-way valve 25 and a water level sensor 37 for detecting the water level of the bathtub B. In addition, between the first pipe line 23A and the third pipe line 23C, in order to suppress the temperature of hot water discharged into the bathtub B at the time of reheating,
A bypass pipe line 23D for circulating a portion of hot water without passing through the bath heat exchanger 12 is provided so as to bypass the water flow switch 35, the bath thermistor 36, and the bath heat exchanger 12, thereby preventing burns. It is possible to quickly reheat the heat while ensuring safety, and also to smoothly generate air bubbles for massage, which will be described later.

Note that the bath circulation circuit 23 is connected to the second pipe line 23.
A third pipe line 23C is connected to the wall of the bathtub B using a double-structured circulation fitting 26 arranged concentrically in the bathtub B.
In the circulation fitting 26, an opening of a separately provided air pipe 27 is arranged in the third pipe line 23C, and when the air solenoid valve 28 is opened under predetermined control when the pump 24 is activated, the air is massaged toward the bathtub B. Generates bubbles for use.

The main heat exchanger 11 and the bath heat exchanger 12 are equipped with a main burner 2 and a bath burner 3 to which fuel gas is supplied through a gas supply pipe 4, and each burner 2
, 3 are controlled by a control device 40, which will be described later. When the control device 40 is normally installed, a power switch (not shown) is turned on, and power is constantly supplied to the control device 40.
A main remote controller 50 installed in the kitchen, etc., and a bath remote controller 60 installed in the bathroom, each remote controller 5
In response to operation signals from 0 and 60, the respective operating operations described later are performed, and for this purpose, as shown in FIG. It has each functional section of a control section 45 and a bath control section 46.

The communication control unit 41 includes remote controllers 50 and 6.
A two-wire cable is provided between each remote controller 50 and
, 60, and each remote controller 50 is transmitted superimposed on the power supply voltage using the same cable.
, 60, each remote controller 50, 60
Send operating signals and display signals to the The operation control unit 42 controls hot water filling operation, hot water supply operation, reheating operation, etc. according to the operation state of one of the remote controllers to which operation priority has been given. There is a timer section 42a for measuring operating time, standby time, etc. for control purposes.

The operation priority is determined mainly according to the operating state of the priority changeover switch 61 provided on the bath remote control 60, and each time the priority changeover switch 61 is pressed once, the operation priority is bath remote control 6
The operation priority of 0 is alternately changed, and a message to that effect is displayed on the remote control to which the operation priority has been given. Further, in this embodiment, when the main remote controller 50 is given operation priority and a fluctuation operation, which will be described later, is instructed by the fluctuation switch 62 provided on the bath remote controller 60, the priority changeover switch 61 is activated. Even if the operation priority switching operation to the bath remote control 60 is not performed, the operation priority switching operation to the bath remote control 60 is automatically performed, and the operation priority is given to the bath remote control 60.

In the hot water filling operation, when the hot water filling switch provided on each remote controller 50, 60 is operated, the hot water filling valve 20 is activated.
, the first two-way valve 22 and the second two-way valve 25 are opened in a predetermined order to start supplying hot water to the bathtub B, and the water filling flow rate indicates that hot water has been filled to a predetermined amount according to the set water level. When detected by the sensor 34, the water filling operation is switched to based on the water level detected by the water level sensor 37, and when the set water level is detected, the hot water filling operation is ended. During this time, the temperature control section 43 and the fuel control section 4
4. The main heat exchanger 11 is heated by the main burner 2 by controlling the water amount controllers 45 respectively. Thereafter, in order to bring the water temperature in the bathtub B to the set water filling temperature, the pump 24 is driven, and the bath thermistor 36 detects the water temperature in the bathtub B. If the water temperature in the bathtub B has not reached the set water filling temperature, The bath controller 46 is controlled to carry out reheating operation, and the bath heat exchanger 12 is heated by the bath burner 3 until the hot water reaches the set temperature.

Normally, the target temperature for hot water heated during hot water supply operation is a constant temperature determined based on the hot water setting temperature of the remote controller to which operation priority is given. When using the shower as one of the uses, a fluctuation operation function is provided to perform a "fluctuation shower" in which the hot water temperature is changed in a predetermined pattern to obtain a massage effect using warm water. For this reason, the hot water supply operation of this embodiment includes a hot water supply mode in which normal hot water supply is performed to maintain the outlet temperature at a constant target temperature, and a fluctuation mode in which a "fluctuation shower" is performed. The hot water supply mode is a hot water supply operation performed at a fixed hot water supply temperature when the fluctuation mode is not instructed by the fluctuation switch 62. In the hot water supply mode, each remote controller 50
, 60 enters a hot water supply standby state in response to operation, a hot water tap (not shown) is opened, and the water supply flow rate sensor 31 detects that water passing through the main heat exchanger 11 in an amount equal to or higher than the operation start flow rate is detected. Then, the main burner 2 performs heating by controlling the temperature control section 43, fuel control section 44, and water amount control section 45 based on the hot water supply setting temperature of the remote control to which operation priority has been given.

The fluctuation mode is activated in response to the operation of the fluctuation switch 62 provided on the bath remote control 60, and changes the outlet temperature of hot water in a predetermined pattern. ” is used when performing. As the fluctuation mode, when the fluctuation switch 62 is operated to instruct the fluctuation mode during normal hot water supply in the hot water supply mode, the fluctuation operation is started in accordance with the switch operation, and the temperature of the hot water tapped out changes in a predetermined manner. . In the hot water supply mode, if the fluctuation mode is instructed by the fluctuation switch 62 in a hot water supply standby state in which hot water supply operation is possible, when the fluctuation switch 62 is operated, the fluctuation mode changes to the fluctuation standby state, and then the hot water supply operation of the shower head, etc. When the stop valve communicating with the mouth is opened to start supplying hot water, a fluctuation operation is started and the temperature of the hot water changes in a predetermined pattern.

The change in the hot water outlet temperature during the fluctuation operation is caused by the fact that the hot water supply target temperature changes in a predetermined pattern, and the target temperature in the temperature control section 43 and the gas supply amount in the combustion control section 44 change accordingly. It is done. In the hot water supply mode, when the hot water supply standby state in which hot water supply operation is not performed is changed to the fluctuation mode by operating the fluctuation switch 62, the fluctuation standby state is maintained for a predetermined time (for example, 15 minutes) after entering the fluctuation standby state. When a predetermined period of time has elapsed, the fluctuation mode is automatically canceled and the hot water supply mode is entered, and the hot water supply standby state is entered. In addition, if hot water is supplied and the fluctuation operation is started within a predetermined time after entering the fluctuation mode in the fluctuation standby state as the fluctuation mode, or if the fluctuation mode is switched to the fluctuation mode by operating the fluctuation switch 62 during hot water supply operation. When the fluctuation motion is started, the fluctuation motion is possible only for a predetermined period of time (for example, 15 minutes) after the start of each fluctuation motion, and the fluctuation motion is continued for a predetermined period of time (for example, 15 minutes) or more after the start of the fluctuation motion. in case of,
When a predetermined period of time has elapsed, the fluctuation mode is automatically canceled and the fluctuation operation ends, and thereafter, the hot water supply mode is changed to normal hot water supply operation. Furthermore, even when the flow rate detected by the hot water supply flow rate sensor 31 becomes lower than the operation stop flow rate and the hot water supply ends due to closing a water shut-off valve during the fluctuation operation in the fluctuation mode, the fluctuation operation causes the combustion of the main burner 3 to stop. When the machine stops, the fluctuation mode is automatically canceled and the hot water supply mode is set.If hot water is supplied again after that, it is assumed that it is within the specified time from the switching to the fluctuation mode or the start of the fluctuation operation. No fluctuation operation is performed, and normal hot water supply operation is performed in the hot water supply mode.

On the other hand, if the fluctuation switch 62 is operated during the above-mentioned hot water filling operation, the hot water filling operation is temporarily interrupted and the fluctuation standby state is set as the fluctuation mode in the hot water supply operation, and the fluctuation standby state is canceled or the fluctuation is stopped. When the fluctuation mode is canceled by the end of the operation, the interrupted hot water filling operation is resumed, and the hot water filling operation is continued from the state before the interruption. It should be noted that if the fluctuation operation is instructed to stop by operating the fluctuation switch 62 during the fluctuation standby state or fluctuation operation, or if the operation priority is switched from the bath remote control 60 to the main remote control 50 by operating the priority changeover switch 61. In this case, the fluctuation mode for the fluctuation operation is canceled and the fluctuation standby state is changed to the normal hot water supply standby state or from the fluctuation operation to the normal hot water supply operation.

The temperature control section 43 has a feedforward control section (hereinafter referred to as "FF control section") 43a and a feedback control section (hereinafter referred to as "FB control section") 43b. The target heating amount of the main burner 2 is determined based on each set temperature transmitted from each remote controller 50, 60, each detection information of the water supply temperature thermistor 32, hot water temperature thermistor 33, and hot water supply flow rate sensor 31. During normal hot water supply operation and hot water filling operation, the FF control unit 43a performs feedforward control to determine the target temperature based on each set temperature, the water supply flow rate, and the target heating amount based on the water supply temperature, and the hot water output temperature thermistor 33 detects the feed forward control. When the tapped hot water temperature satisfies a predetermined condition, the FB control unit 43b further performs feedback control based on the tapped hot water temperature together with feedforward control to stabilize the tapped hot water temperature. In the FF control unit 43a of this embodiment, the target heating amount (gas supply amount) by feedforward control
Qff is given by the following equation. Qff=(Tset-Tin)×W÷EX where, Ts
et is the target temperature set by the remote control, Tin is the feed water temperature detected by the feed water temperature thermistor 32, W is the feed water flow rate detected by the feed water flow rate sensor 31, and EX is the heat exchange rate. Further, the target heating amount (gas supply amount) Q when feedback control by the FB control unit 43b is performed together with feedforward control is given by the following equation. Q=Qff+P+I+D Here, P is the proportional correction amount in feedback control,
I is the integral correction amount in feedback control, D is the differential correction amount in feedback control, and P=E(
Tset-Tout)×W I=I{n-1}+bWn×(Tset-Tout)D
=ΔTout×d. In each of the above equations, E is a proportional constant, Tout is the hot water temperature detected by the hot water hot water temperature thermistor 33, I{n-1} is the previously determined integral correction amount, and b
is an integral constant, Wn is the current flow rate, ΔTout is the difference in outlet temperature between this time and the previous time, and d is a negative constant. On the other hand, in the fluctuation operation during hot water supply operation, the target temperature is determined only by feedforward control without performing any of the above feedback control. That is, the above proportional correction amount P
, target heating amount Q without using the integral correction amount I and the differential correction amount D
Combustion control is performed only by ff. As a result, the hot water temperature in the fluctuation operation can be quickly changed according to the target temperature, the temperature change characteristics of the hot water can be improved, and an excellent massage effect can be obtained.

When the flow rate detected by the water supply flow rate sensor 31 exceeds the operating flow rate, the combustion control unit 44 operates an ignition device (not shown), and also operates a gas proportional valve 5 disposed in the gas supply path 4 to the main burner 2. Gas solenoid valve 6, 6a, blower 7
are controlled in a predetermined sequence to perform the ignition operation, and when ignition is detected by a flame detection member such as a flame rod or thermocouple (not shown), the temperature control unit 43 Determine the gas supply amount and drive the blower 7 accordingly,
The rotational speed of the blower 7 is detected and each of the above-mentioned valves is controlled to heat the water passing through the main heat exchanger 11 to a target temperature. Further, as a safety control, if a misfire is detected by the flame detection member during heating, each gas solenoid valve 6, 6a is closed to stop the supply of fuel gas to the main burner 2.

The water flow control unit 45 controls the opening degree of the hot water flow servo 16 and the opening/closing state of the water bypass solenoid valve 19 to adjust the flow rate of water supplied by the water supply pipe 13 to a flow rate corresponding to the heating capacity of the main burner 2. Adjust to ensure hot water supply flow rate and prevent drainage. The bath control unit 46 controls the first two-way valve 2 under control from the operation control unit 42 during boiling and reheating operations as the final operation of the hot water filling operation.
2 is closed and the second two-way valve 25 is opened to drive the pump 24. When the water flow is detected by the water flow switch 35, an ignition device (not shown) is activated, and the bath electromagnetic valve 8 and the bath fan 9 are activated. is operated to control the combustion of the bath burner 3, and the combustion of the bath burner 3 is stopped when a predetermined temperature is detected by the bath thermistor 36 or when a predetermined time has elapsed. Note that 4A in the gas supply path 4 is a solenoid valve for stopping all gas supply to each burner 2, 3, and 8a is a gas governor for keeping the gas supply pressure constant.

Each of the remote controllers 50 and 60 has a microcomputer operated by electric power supplied from the control device 40, and is equipped with an operation switch, a hot water filling switch, etc. (not shown), and a hot water supply temperature as a target temperature in each operation. Equipped with several setting switches for setting the temperature or hot water filling temperature, etc., and a liquid crystal display device for displaying the operation status and operating status of each, hot water supply operation and hot water filling operation can be performed according to the operation of each switch. The instructions and setting information for each operation are transmitted to the control device 40. In particular, the bath remote control 60 is equipped with a priority changeover switch 61 for setting the hot water supply temperature preferentially with respect to the main remote control 50, and also sets the hot water output temperature to a predetermined value in order to give a massage effect when using the shower in the hot water supply operation. A fluctuation switch 62 is provided for performing a "fluctuation shower" that changes the pattern.

The functional configuration and functions of the bath remote controller 60 for hot water supply operation will be explained below. As shown in FIG. 3, the bath remote control 60 includes a hot water supply temperature setting section 71 that sets a hot water supply target temperature according to a signal from a hot water supply temperature setting switch 63, which is composed of a pair of push button switches for setting the hot water supply temperature, and a fluctuation unit. A fluctuation temperature generating section 72 for changing the hot water supply target temperature in accordance with a fluctuation operation instruction to the switch 62, and a fluctuation temperature generating section 72 for changing the hot water supply target temperature in accordance with a fluctuation operation instruction to the switch 62, and selecting one of these according to the hot water supply mode or fluctuation mode in the hot water supply operation and controlling the hot water supply temperature by the bath remote control 60. There is an operation selection section 73 for setting the hot water supply target temperature.

In the hot water supply mode in which no fluctuation operation is performed, the hot water supply temperature setting section 71 controls the hot water supply temperature setting switch 6.
In response to the push operation to 3, the temperature is changed step by step between 35°C and 75°C, and the temperature is set as the hot water target temperature.
Transmit to 0. Furthermore, when switching from the fluctuation mode to the hot water supply mode, the upper limit temperature in the fluctuation operation determined by the upper limit temperature determination section 74 of the fluctuation temperature generation section 72, which will be described later, is set as the hot water supply setting temperature in the hot water supply operation.

The fluctuation temperature generating section 72 is a functional section for generating a hot water supply target temperature that changes in a predetermined pattern in order to change the outlet temperature during the fluctuation operation in the fluctuation mode, and the upper limit temperature determining section 74 , a basic signal generator 75, a signal selector 76, and a lower temperature limiter 77.

The upper limit temperature determination unit 74 is a part that determines the upper limit temperature of the hot water supply target temperature that changes in a predetermined pattern during the fluctuation operation, and basically sets the hot water supply temperature when the hot water supply mode is switched to the fluctuation mode. The hot water supply setting temperature of section 71 is determined as the upper limit temperature of the hot water supply target temperature in the fluctuation operation. However, considering the purpose and usage of "Yuragi Shower" aimed at massaging effects, temperatures that are higher or lower than necessary for the human body are undesirable from a safety and sensory perspective, so the upper limit that can be determined is The temperature is limited to a range of 39°C to 44°C, and if the target hot water temperature set in the hot water temperature setting section 71 exceeds 44°C, the maximum temperature is set to 44°C, and the target hot water supply temperature is set to 44°C. If the temperature is below 39°C, the minimum upper limit temperature is set to 39°C, and for temperatures between 39°C and 44°C, the temperature set by the hot water temperature setting switch 63 is set to the upper limit temperature. Determine as.

The basic signal generating unit 75 determines in advance so that the power spectrum of temperature change is 1/f with respect to its frequency f, as shown in FIG. a signal storage unit that stores several signal patterns S0, S1, S2, and S3, and a signal that reads out the signal patterns S0 to S3 and shifts their upper limit values to match the upper limit temperature of the upper limit temperature determination unit 74. When the fluctuation operation is started, each of the signal patterns S0 to S3 is read out in a predetermined order instructed by a signal selection section 76, which will be described below, and is used as a signal for the hot water supply target temperature. In this embodiment, the fluctuation operation does not start changing the outlet temperature until the outlet temperature reaches the upper limit temperature, and when the control device 40 transmits that the upper limit temperature has been detected by the outlet hot water temperature thermistor 33, the outlet hot water temperature At the beginning of the fluctuation operation, the initial signal S0, in which the temperature simply changes between the maximum value and the minimum value included in the changing signal patterns S1 to S3, is read. Then, each signal pattern S1 to S3 is read out in a predetermined order according to the selection signal of the signal selection section 76, and thereafter, the initial signal S0
and the signal pattern S1 selected according to the signal selection section 76.
~S3 are read out.

The signal selection section 76 is a section that determines the readout order of the plurality of signal patterns S1 to S3 stored in the basic signal generation section 75, and the readout order is "fluctuation shower".
In order to prevent the user from perceiving the order of the signal patterns S1-S3, they are read out in a different order each time a fluctuation operation is performed. Here, the reading order of each signal pattern S1 to S3 is calculated by a predetermined calculation formula based on the number of fluctuation operations performed by the fluctuation switch 62, and this is calculated sequentially even during the fluctuation operation, so that the fluctuation operation is relatively Even if the length of time is increased, the user will not notice the pattern of change in the hot water temperature.

Depending on the set upper limit temperature, the temperature signal from the basic signal generator 75 read as the hot water supply target temperature may include a low target temperature that is not suitable as the hot water supply target temperature. If combustion control is performed according to the conditions of use, there is a possibility that malfunctions such as drainage may occur depending on the usage conditions. In order to prevent such defective operation, the lower limit temperature limiter 77 limits the lowest target temperature to a temperature that does not cause defective operation in case the temperature signal from the basic signal generator 75 includes a low target temperature. Correct to. In this embodiment, among the temperature signals shifted by the signal readout section of the basic signal generation section 75, all temperature signals below 30.degree. C. are corrected to 30.degree.

The operation selection section 73 is a functional section for changing the set state of the hot water supply target temperature according to the hot water supply mode or fluctuation mode that is switched depending on the operation state of the fluctuation switch 62, etc. In the case of a fluctuation standby state or fluctuation operation in which the hot water supply target temperature is determined by the temperature generating section 72, the fluctuation standby state or fluctuation operation is terminated according to the operation of the fluctuation switch 62 or according to each of the above conditions. When information indicating that the fluctuation mode has been canceled is transmitted from the control device 40, the hot water supply temperature setting unit 71 switches to setting the hot water supply target temperature. As a result, in the hot water supply mode, the hot water supply target temperature is set by the hot water supply temperature setting unit 71 in both the hot water supply standby state and the hot water supply operation, and in the fluctuation mode, the hot water supply target temperature is set in both the hot water supply standby state and the fluctuation operation. A hot water supply target temperature is set by the fluctuation temperature generating section 72, and the hot water outlet temperature is changed accordingly.

Next, the operation in the fluctuation mode of the gas automatic water heater 1 of this embodiment having the above configuration will be explained based on FIG. When the fluctuation switch 62 is turned on and the fluctuation mode is instructed (YES in step 1)
), it is determined whether or not the main remote control 50 is given the operation priority, and if the operation priority is given to the bath remote control 60 (NO in step 2), the hot water supply mode is switched to the fluctuation mode. is performed (step 3), and at this time, a 15-minute timer starts counting in the timer section 42a. If the main remote control 50 is given the operation priority (YES in step 2), the operation priority is switched (step 4), the bath remote control 60 is given the operation priority, and then the operation priority is given to the bath remote control 60, and then in step 3. Then, the hot water supply mode is switched to the fluctuation mode, and the 15-minute timer starts counting. In the temperature adjustment control section 43, the FB control section 43b for feedback control no longer functions, only the FF control section 43a for feedforward control functions, and the detection information from the hot water temperature thermistor 33 is ignored. Note that when the hot water supply mode is switched to the fluctuation mode, the bath remote controller 60 and the main remote controller 50 display on their respective liquid crystal display devices that the mode has been changed to the fluctuation mode. In addition, when the operation priority is switched to the bath remote control 60 by switching the operation priority,
The main remote controller 5 displays a display indicating operation priority accordingly.
0 to the bath remote control 60.

When the fluctuation mode is entered, the operating state is determined by determining whether hot water supply operation is being performed (
Step 5). If hot water supply operation is being performed (YES in step 5), proceed to step 20,
A fluctuation operation is started, whereby the hot water supply target temperature changes in a predetermined pattern, and the hot water outlet temperature changes accordingly. If hot water supply operation is not being performed (NO in step 5), it is determined whether hot water filling operation is being performed (step 6). If hot water filling operation is not being performed (NO in step 6), main heat exchanger 1
It is determined whether the flow rate of water passing through the main burner 2 is equal to or higher than the operating flow rate for starting the operation of the main burner 2 (step 9). If the hot water filling operation is in progress (YES in step 6), the hot water filling operation is temporarily interrupted (step 7).
, 3 seconds after starting the process to interrupt the hot water filling operation (
(YES in step 8), proceed to step 9.

If the flow rate detected by the water supply flow rate sensor 31 is not equal to or higher than the operating flow rate (NO in step 9), it is determined whether or not there is an instruction to stop the fluctuation operation by the fluctuation switch 62 (step 10), and the fluctuation switch 62
If there is no off operation (NO in step 10),
), and further determines whether or not there has been an operation to switch the operation priority from the bath remote control 60 to the main remote control 50 using the priority changeover switch 61 (step 11), and if there is no operation priority switch operation (in step 11). NO
), it is determined whether 15 minutes have elapsed since the start of the 15-minute timer (step 12), and if 15 minutes have not elapsed (NO in step 12), the process moves to step 9 and the steps described above are performed. Repeat each determination from 9 to 12. If the answer is NO in any of the above steps 9 to 12, the control device 40 repeats the loop of steps 9 to 12 until the stop valve is opened and hot water supply operation by fluctuation operation is started. It enters the fluctuation standby state.

In the above-mentioned fluctuation standby state, if the flow rate detected by the water supply flow rate sensor 31 becomes equal to or higher than the operating flow rate due to a stop valve being opened, etc. (YES in step 9), at that point the timer unit 42a is activated. After clearing the 15-minute timer and restarting it (step 13), the process moves to step 20 and a fluctuation operation is performed. On the other hand, when the fluctuation switch 62 is turned off in the fluctuation standby state (YES in step 10), the fluctuation mode is canceled (step 14), and the fluctuation switch 62
Returns to the state before it was turned on. Similarly, in the fluctuation standby state, when the priority changeover switch 61 performs an operation priority switch 61 and the operation priority is switched from the bath remote control 60 to the main remote control 50 (YES in step 11), The fluctuation mode is canceled (step 14). Also, the fluctuation standby state is 1
When five minutes have elapsed (YES in step 12), the fluctuation mode is automatically canceled even if the above-mentioned cancellation operations are not performed (step 14). When the fluctuation mode is canceled in the fluctuation standby state, the fluctuation standby state returns to the hot water supply standby state, or the hot water filling interrupted state returns to hot water filling operation.

Next, the fluctuation operation in step 20 will be explained with reference to FIG. Here, the fluctuating operation refers to the fact that hot water is actually being supplied in the fluctuating mode, and the temperature of the outlet hot water changes in a predetermined pattern. When the process moves to step 20 based on the determination in step 5 or step 9 above, a fluctuation operation is started (step 21), and an upper limit temperature is determined according to the hot water supply target temperature of the hot water temperature setting section 71 in the bath remote control 60. The fluctuation temperature, which changes in a predetermined pattern according to the temperature, is transmitted to the temperature adjustment control section 43 via the communication control section 41 of the control device 40. At this time, the temperature control section 4
3, the target heating amount is determined only by the FF control section 43a, and the combustion control section 44 controls the combustion of the main burner 2 accordingly. Once the fluctuation operation is started, the operation is stopped depending on the following determination results. The conditions for stopping the fluctuation operation are almost the same as the conditions for canceling the fluctuation mode in the fluctuation standby state described above, and when the flow rate detected by the water supply flow rate sensor 31 becomes less than the operation stop flow rate (YES in step 22), Fluctuation switch 62
When the fluctuation operation is turned off (YES at step 23), when the operation priority is switched from the bath remote control 60 to the main remote control 50 by the priority changeover switch 61 (YES at step 24)
S), if the duration of the fluctuation motion exceeds 15 minutes (YES in step 25), the fluctuation motion ends (step 26), and then the process moves to step 14. When the fluctuation operation ends, the fluctuation mode is automatically canceled. In addition, when the fluctuation operation is completed according to the predetermined conditions in step 20, and the process moves from steps 23, 24, and 25 to step 26, the upper limit temperature is set as the hot water supply target temperature until the flow rate becomes lower than the operation stop flow rate. Hot water supply operation will continue. Further, when the process moves from step 22 to step 26 and the fluctuation operation is completed, the process returns to the hot water filling operation or hot water supply standby state before entering the fluctuation mode.

As described above, in the present invention, when the fluctuation operation is performed, feedback control based on the detection information of the outlet hot water temperature thermistor 33 is not performed, so The hot water temperature can be changed with good responsiveness. Therefore, “
It has a great massage effect when used for a "fluctuation shower". In addition, in this embodiment, in the fluctuation operation,
Although only feedforward control is performed by the FF control unit 43a, once feedback control is performed by the FB control unit 43b, temperature control control with the proportional correction amount P added immediately before entering the fluctuation mode is performed. By doing so, it is possible to eliminate temperature errors due to variations in equipment, etc. In this embodiment, in normal hot water supply operation and hot water filling operation, the heating amount of the heating source is controlled based on the inflow temperature to the water heating circuit, the water supply temperature, the hot water outlet temperature, and the target temperature. Alternatively, control may be performed based only on the target temperature. In this embodiment, the water supply pipe 13
Although a water bypass pipe 14 and a water bypass valve 19 which bypass the hot water tap pipe 15 are shown, the water bypass pipe 14 and the water bypass valve 19 may be provided without each of them.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of a control device for a gas automatic water heater showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing the configuration of a gas automatic water heater according to an embodiment of the present invention.

FIG. 3 is a functional block diagram of a bath remote control in a gas automatic water heater showing an embodiment of the present invention.

FIG. 4 is a waveform diagram showing a waveform of a target temperature generated by a fluctuation temperature generating section in a bath remote control for a gas automatic water heater according to an embodiment of the present invention.

FIG. 5 is a flowchart for explaining the operation regarding the fluctuation mode in the gas automatic water heater according to the embodiment of the present invention.

FIG. 6 is a flowchart for explaining the fluctuation operation in the gas automatic water heater according to the embodiment of the present invention.

[Explanation of symbols]

1 Gas automatic water heater (water heater) 2 Main burner (heating source) 11 Main heat exchanger (heat exchanger)

Claims (1)

[Claims] 1. Feed water temperature detection means for detecting the inflow temperature of water flowing into a water heating circuit including a heat exchanger equipped with a heating source, and a water supply flow rate detection means for detecting the flow rate of water flowing into the water heating circuit. means, a hot water outlet temperature detection means for detecting the outlet temperature of the water heated by the water heating circuit, and a target temperature setting means for setting a target temperature of the hot water heated by the water heating circuit, and controlling the heating source. The water heater control device has a fluctuation operation function that changes the heating amount of the heating source in accordance with time changes in order to change the temperature of hot water heated by the water heating circuit in accordance with time changes, and usually In the hot water supply operation, feedback control is performed at least based on the detection information of the hot water outlet temperature detection means, and in the fluctuation operation, the control is not performed based on the detection information of the hot water outlet temperature detection means. Device.