JP3310065B2 - Water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a can body having a hot water supply heat exchanger connected to a water supply pipe and a hot water supply pipe, and a reheating side heat exchanger connected to a circulating water channel of bathtub water. The present invention relates to a one-can-two-channel hot-water supply device that is heated by a heating unit.

[0002]

2. Description of the Related Art In this type of hot water supply apparatus, which often uses fins, the heat of a reheating-side heat exchanger is conducted to the hot-water supply side heat exchanger when the bathtub water is heated, and the hot-water supply-side heat exchanger stays. If the water is boiled and hot water is supplied after the bathtub water is heated, the boiling water may blow out from a shower or a coiled pipe and be dangerous.

In order to prevent such a danger, a hot water supply apparatus disclosed in Japanese Patent Publication No. 1-28300 detects the temperature of stagnant water in a heat exchanger on a hot water supply side and supplies hot water during heating of bathtub water. When the temperature of the accumulated water in the side heat exchanger rises, the amount of heating is reduced or stopped, and during this time, the heat is transferred to the additional heat exchanger and the temperature of the accumulated water in the hot water supply heat exchanger decreases. By repeating the operation of returning to the steady heating again, the boiling of the retained water in the hot water supply side heat exchanger is prevented.

[0004]

Generally, it is desired to shorten the time required for boiling the bathtub water by reheating, but the above-mentioned conventional hot water supply apparatus has a problem in that the accumulated water in the hot water supply side heat exchanger is not heated. When the temperature rises, the amount of heating is reduced or stopped. This is a repetition of the operation. Since the control is performed with a margin for increasing the amount of heating, there is a problem that the boiling speed is low.

The present invention has been made to solve the above problems, and has as its object to provide a water heater capable of quickly boiling bath water.

[0006]

SUMMARY OF THE INVENTION The present invention provides a can body having a water supply pipe and a hot water supply side heat exchanger connected to a hot water supply pipe, and a reheating side heat exchanger connected to a bathtub water circulation channel. In a hot water supply device that heats with a common heating unit, the heating amount that controls the heating amount of the heating unit so that the temperature of the hot water supply side heat exchanger approaches the target value while the bathtub water is being heated by the additional heating side heat exchanger A heating means for detecting a pipe temperature or a water temperature in the pipe of the hot water supply side heat exchanger; and a feedback calculation for calculating a feedback control amount based on an output of the heat exchange temperature detecting section. Means, bathtub temperature detecting means for detecting a bathtub water temperature, and feedforward calculating means for calculating a feedforward control amount based on an output of the bathtub temperature detecting means.

[0007] Preferably, the heating amount control means further comprises:
A transition unit configured to execute control according to the feedforward control amount at the start of heating and execute control according to the sum of the feedforward control amount and the feedback control amount during steady-state heating.

[0008]

[0009]

Further, an overshoot detecting means for detecting the occurrence of overshoot in the water temperature in the pipe of the hot water supply side heat exchanger based on the output of the heat exchange temperature detecting section, and a heating section based on the output of the overshoot detecting means. And an overshoot suppressing means for extinguishing the fire.

Still further, a configuration is provided which comprises a differentiating means for detecting a change in the output of the heat exchange temperature detecting section, and a heating amount suppressing means for suppressing the heating amount of the heating section when the output of the differentiating means exceeds a predetermined value. You can also

The heating section comprises first and second heating sections, and preferably includes a heating section selection means for selecting one or both of the first and second heaters according to the amount of heating. .

[0013]

According to the present invention, during the heating of the bathtub water by the additional heat exchanger, the heating amount is controlled so that the temperature of the hot water supply heat exchanger approaches the target value. Detect the pipe temperature or the water temperature in the pipe, calculate the feedback control amount based on the detected value, detect the bathtub water temperature, calculate the feedforward control amount based on the detected value, and follow these two control amounts. Since the heating amount is controlled, the heating amount can be increased as much as possible within a range in which the boiling water on the hot water supply side can be prevented from boiling, whereby the bath water can be quickly boiled.

Since this type of water heater has a relatively large response delay, control is performed in accordance with the feedforward control amount at the start of heating, and during the steady heating heat, the control is performed in accordance with the sum of the feedforward control amount and the feedback control amount. By executing the control described above, more detailed control is possible.

[0015]

[0016]

If the heating amount is controlled in accordance with the feedback control amount, there is a concern that boiling of the stagnant water in the hot water supply side heat exchanger due to a response delay may occur. This problem is solved by detecting the occurrence of overshoot in the temperature of the hot water supply side heat exchanger and extinguishing the heating section.

Further, by detecting a change in the output of the heat exchange temperature detecting section and suppressing the amount of heating of the heating section in accordance with the detected value, the boiling of the stagnant water of the hot water supply side heat exchanger due to a response delay is reduced. It can be reliably prevented.

By the way, when only a single heating unit is provided for controlling the amount of heating, the proportional control range is narrow, and it may be difficult to perform fine control. This can be solved by using the first and second heating units as the heating unit and selecting one or both of the first and second heaters according to the amount of heating.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings.

FIG. 1 is a schematic configuration diagram of one embodiment of the present invention. In FIG. 1, the can body 1 includes a hot water supply side heat exchanger 3 and a reheating side heat exchanger 4 that share the fins 2. Among these, the hot water supply side heat exchanger 3 is connected to the water inlet channel 5 and the tapping pipe 6, and a tap tap 7 is provided at a terminal of the tapping pipe 6. The additional heat exchanger 4 is connected to a circulation channel 9 for circulating water in the bathtub 8, and a circulation pump 10 for forcibly circulating hot water is provided in the circulation channel 9. .

In order to heat the hot water supply side heat exchanger 3 and the additional heating side heat exchanger 4, a first burner 11 and a second burner 12 are provided.
It has. These first burner 11 and second burner 12
Via the first on-off valve 13 and the second on-off valve 14 respectively
It is commonly connected to a proportional valve 15 for controlling a gas supply amount. Further, a fan 16 for feeding combustion air into the combustion chambers of the first burner 11 and the second burner 12, an igniter 17 for igniting both burners, and a frame rod 18 for detecting and maintaining the ignition state.
It has.

On the other hand, the circulation pump 10, the first on-off valve 13, the second
Off valve 14, the control unit 100 is provided for controlling the proportional valve 15 and the fan 16, the incoming water temperature detecting section 21 for detecting the water temperature T _c of the incoming water path 5, detects the hot water temperature T _h of the hot water pipe 6 Hot water temperature detector 22, a hot water flow rate detector Q for detecting hot water flow rate Q, an outlet temperature detector 24 for detecting the return temperature _{Tf of the} bathtub to the circulation channel 9, and a pipe temperature or pipe of the hot water supply side heat exchanger 3. inner temperature (hereinafter, the heat of exchanger temperature) and the thermal exchange temperature detector 25 for detecting the T _z is provided, the output signal of the detector is taken into the control section 100. Control unit
Additionally fired switch 31 for commanding the add-fired tub 8 to 100, hot water temperature setting unit 32 outputs the set value T _s of the hot water temperature, and bath temperature setting unit 33 is controlled to output the set value T _fs bath temperature It is connected to the unit 100.

FIG. 2 is a block diagram showing a detailed configuration of the control unit 100. Referring to FIG.
1 is a signal for inputting an ON operation signal of the reheating switch 31 to output a combustion start request, and outputs a burning signal when the flame rod 18 is in a heated state, and the ignition control means 102 sets the igniter in accordance with the combustion start request. Make 17 work. The boiling detecting means 103 detects the boiling of the bath water by comparing the return temperature T _f of the bath tub detected by the outlet temperature detecting section 24 with the bath temperature setting value T _{fs of the} bath temperature setting section 33. There, the temperature rise judgment means 104 configured to detect the heat exchanger temperature T _z detected by the heat exchanger temperature detector 25, an increase to dwell temperature compared with moderately low temperature setting value T _zs than the boiling temperature is there. Timer 10
The time required from the start of heating to the steady heating is set in 5, and a time-measuring operation is started by a combustion start request from the combustion start request judging means 101, and a time-up signal is given to the transition means 106 when the set time has elapsed. After the combustion start request is output, the transition means 106 outputs a signal indicating that the timer 105 outputs a time-up signal or the temperature rise determination means 104 detects a temperature rise. Until the start, a combustion initial mode signal is output.

Further, the feed-forward operation means 107 provided that the combustion start request or combustion signals from combustion start request determining means 101 is output, the feedforward control amount F ₀ based on bathtub return temperature T _f intended for calculating, computing means 108 obtains the feedback control amount F _B running PI calculation on the deviation between the heat exchanger temperature T _z and the temperature set point T _zs, migration means 106 outputs the initial combustion mode signal and outputs a feedback control amount F _B on the condition that you are not. The heating amount control means 109 intended for calculating the heat quantity F by adding the feed forward control amount F ₀ and the feedback control amount F _B, the heating section selection means
Reference numeral 110 denotes a comparison between the heating amount F and the minimum opening _F12min of the proportional valve 15 when the first burner 11 and the second burner 12 are simultaneously burned, and selects single combustion or simultaneous combustion. On condition that the combustion start request or the in-combustion signal is output from the judging means 101 and the boiling detection signal is not output from the boiling detecting means 103, an open command to the first on-off valve 13 is selected when the single combustion is selected. , When the simultaneous combustion is selected, the first on-off valve 13
And an open command for both the second opening and closing valve 14 is output. First on-off valve control means 111 and second on-off valve control means
112 opens the corresponding on-off valve in response to these opening commands. Further, the proportional valve control means 113 controls the opening of the proportional valve 15 in accordance with the heating amount F on condition that the selection signal is outputted from the heating section selecting means 110.

The overall operation of the embodiment constructed as described above will be described below. First, by setting an appropriate temperature by the hot water temperature setting unit 32 so as to put water filling the tub 8 temperature setting value T _s is applied to the control unit 100, hot water plug 7
The controller 100 opens the first opening / closing valve 13 and / or the second opening / closing valve 14 and the proportional valve 15 and activates the fan 16 and the igniter 17 at the stage when is opened. In this case, the control unit 100 tapping temperature setting unit 32 according to the temperature setting value T _s, is detected by the incoming water temperature detecting section 21 feedwater temperature T _c, the hot water temperature T _h detected by the hot water temperature detecting section 22, the flow rate detection unit The heating amount F is calculated based on the tap water flow rate Q detected by 23, and the opening of the proportional valve 15 is controlled so that the heating amount F is obtained. The calculation of the heating amount has been proposed and known in the art, and a description thereof will be omitted. Thereafter, when the amount of hot water in the bathtub 8 reaches a predetermined value and the tap 7 is closed, the control unit 100 closes the proportional valve 15 and sets the first opening / closing valve 13 and the second opening / closing valve.
Close 14 to end the filling control.

Next, in order to heat the water or warm water stored in the bathtub 8 to an appropriate temperature, the reheating switch 31 is turned on and the bath temperature setting unit 33 sets the hot water temperature. Starts the circulation pump 10 to circulate the bathtub water, and further calculates the heating amount F based on the return temperature _Tf of the bathtub detected by the outlet temperature detection unit 24, so that the heating amount F is obtained. The selection of the heating unit and the control of the proportional valve 15 are executed, and the fan 16 and the igniter 17 are simultaneously activated.
In this case, it is necessary to take measures to prevent the retained water in the hot water supply side heat exchanger 3 from boiling.

FIG. 2 is a functional block diagram of the control unit 100 configured to prevent boiling of the stagnant water in the hot water supply side heat exchanger 3 and to quickly boil the bathtub water. The operation will be described below. .

When the additional heating switch 31 is turned on, the combustion start request judging means 101 outputs a combustion start request. The ignition control means 102 operates the igniter 17 according to the combustion start request. In response to the combustion start request, the timer 105 starts the time counting operation, and the timer 105 outputs a time-up signal or the temperature rise determining means 104
_The transition means 106 outputs a combustion initial control mode signal until the rise of _z is detected. At this time, the feed-forward operation means 107 conditions the presence of a combustion start request, calculates a feedforward control amount F ₀ based on bathtub return temperature T _f, the feedback arithmetic unit 108 and the temperature setting heat exchanger temperature T _z Request feedback control amount F _B running PI computation based on the deviation between the value T _zs. However, migration means 10
While 6 is outputting initial combustion mode signal, since the output from the feedback calculation unit 108 of the feedback control amount F _B is blocked, only the feed forward control amount F ₀ is applied to the heating amount control means 109. Therefore, the heating amount control means 109 changes the feedforward control amount F ₀ to the heating amount F
Output as The heating unit selecting means 110 performs the simultaneous combustion of the heating amount F and the first burner 11 and the second burner 12 on the condition that there is a combustion start request and the boiling detecting means 103 does not detect the boiling. Opening F of proportional valve 15
Compare with _12min to select single combustion or simultaneous combustion.
That is, if F < _F12min , single combustion is selected and an open command is given to the first on-off valve control means 111. If F ≧ _F12min , simultaneous combustion is selected and the first on-off valve control means 111 and An open command is given to both the two on-off valve control means 112. The proportional valve control means 113 controls the opening of the proportional valve 15 so as to obtain the heating amount F corresponding to each of the selected states of the single combustion and the simultaneous combustion. Thus, the ignition of the burner and the initial combustion control are performed in conjunction with the ignition operation of the ignition control means 102.
Further, the flame rod 18 is heated, and the combustion start request judging means 101 outputs a burning signal.

During this time, the boiling detecting means 103 compares the return temperature _{Tf of the} bathtub detected by the outlet temperature detecting section 24 with the set value _Tfs of the bath temperature of the bath temperature setting section 33, and _Tf > _Tfs. , A boiling signal is output. With this boiling signal,
Since the heating section selecting means 110 stops outputting the open command, the first on-off valve control means 111 controls the first on-off valve 13, the second on-off valve control means 112 controls the second on-off valve 14, and the proportional valve control means 113 The fire is extinguished by closing the proportional valves 15 respectively.

On the other hand, the combustion state is continued if I become relationship T _f ≦ T _fs between the set value T _fs bathtub return temperature T _f and a bath temperature of bath temperature setting unit 33. When the timer 105 outputs a time-up signal, the transition means 10
6 stops the output of the combustion initial mode signal. Even before the timer 105 outputs the time-up signal,
If the temperature rise judgment means 104 detects a rise in the heat exchanger temperature T _z, shifting unit 106 stops the output of the initial combustion mode signal. Thus, when the output of the initial combustion mode signal is stopped, the feedback arithmetic unit 108 is heat exchange temperature T _z and the temperature set point T _zs feedback control amount calculated by executing the PI calculation on the deviation between F Output _B.

[0032] Therefore, heating amount control means 109 obtains the heat amount F by adding the feed forward control amount F ₀ and the feedback control amount F _B, is added to the heating section selection means 110 and the proportional valve control unit 113. The heating unit selection means 110 has a heating amount F and a minimum opening degree F _12min of the proportional valve 15 in the case of simultaneous combustion, provided that there is an in-combustion signal and the boiling detection means 103 does not detect boiling. And whether to perform single combustion or simultaneous combustion. The first on-off valve control means 111 and the second
The on-off valve control means 112 controls the first on-off valve 13 and the second on-off valve 14 according to the selected state. The proportional valve control means 113 controls the opening of the proportional valve 15 so as to obtain the heating amount F corresponding to each of the selected states of the single combustion and the simultaneous combustion.

As a result, during the heating of the bathtub water by the additional heat exchanger 4, the heating amount can be increased as much as possible within a range in which the water retained in the hot water supply side heat exchanger 3 does not boil. Can be boiled quickly.

FIG. 3 is a flowchart showing a processing procedure when the microcomputer is provided with the functions of these control units. Hereinafter, a detailed operation at the time of additional heating control will be described according to this flowchart.

First, at step 121, it is determined whether or not combustion is occurring based on the state of the frame rod 18. Refire switch 31
Immediately after the turning-on operation, the process proceeds to step 122 because combustion is not in progress. In step 122, it is determined whether or not there is a request to start combustion. If there is a request to start combustion, the processes in step 123 and subsequent steps are executed, and if there is no request to start combustion, the process ends.

Next, at step 123, a timer is started, and at step 124, the combustion initial control mode is set. Further, at step 125, the initial heating amount, that is, the feedforward control amount F based on the bathtub return temperature _{Tf. In} step 126, the first on-off valve 13 is opened.
At the same time, the igniter 17 is operated.

Next, compared with the minimum opening F _{12 min} of the proportional valve 15 when the feed-forward control amount F ₀ at step 127 was co-fire the first burner 11 and second burner 12, F ₀ < If it is _F12min , the first burner is performed in step 128
The opening degree of the proportional valve 15 is controlled so that the feedforward control amount F ₀ is obtained by the single combustion of 11, and conversely, F ₀ <F ₁₂
Otherwise _min, i.e., it opens the second on-off valve 14 at Step 129 if F ₀ ≧ F _{12 min,} followed by Step 12
At 8, the opening of the proportional valve 15 is controlled so that the feedforward control amount F ₀ is obtained by simultaneous combustion of the first burner 11 and the second burner 12, and the process is terminated.

On the other hand, if it is determined in step 121 that combustion is taking place, then in step 131, the return temperature T
whether have a relationship of T _f> T _fs between the set value T _{fs f} and bath temperature, i.e., to determine whether the bath is boiled, the process of extinguishing at step 132 when the rose boiling Execute and finish the process, and when it is not boiling, step 13
Proceed to step 3.

Next, in step 133, it is determined whether or not the operation is in the initial combustion control mode. If the operation is in the initial combustion control mode, the processing of steps 134 to 135 is executed. I do. Here, in step 134, it is determined whether or not the timer has expired.
5 pipe temperature or heat exchanger temperature T _z of the hot water supply-side heat exchanger 3 is whether the set value T _zs greater than in, i.e., determines whether the increased. If it is determined that the temperature has not risen, the process is terminated. If it is determined that the temperature has risen, the setting of the initial combustion control mode is cleared in step 136. If it is determined in step 134 that the timer has expired, the setting of the initial combustion control mode is cleared in step 136. Then, after clearing the setting of the combustion initial control mode, the process returns to step 137.

Next, at step 137, a PI operation is performed on the difference between the heat exchange temperature T _z and the temperature set value T _zs to obtain the feedback control amount FB. Then, at step 138, the feedforward control amount F _B is obtained. ₀ and feedback control amount F
_The heating amount F is obtained by adding _B. Step 139
And the minimum opening F ₁₂ of the proportional valve 15 during simultaneous combustion with the heating amount F
comparing the _min, then perform the step 140 following the process as long with F <F _{12 min,} unless F <F _{12 min,} i.e., executes step 142 following processing when a F ≧ F _{12 min.}

Therefore, in step 140, the first on-off valve 13 is opened, and in the following step 141, the opening of the proportional valve 15 is controlled so that the heating amount F is obtained by the single combustion of the first burner 11, and the process is terminated. . In step 142, both the first on-off valve 13 and the second on-off valve 14 are opened, and in the following step 143, the proportional valve 15 is controlled so that the heating amount F is obtained by the simultaneous combustion of the first burner 11 and the second burner 12. Control the opening.

The function of each block shown in FIG. 2 can be realized by the above processing procedure.

FIG. 4 is a block diagram showing a detailed configuration of the control unit 100 for preventing boiling due to a response delay due to feedback control. In the figure, elements having the same functions as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted. Here, an overshoot detecting means 114, an overshoot convergence detecting means 115, a differentiating means 116, an overshoot suppressing means 117, and a heating amount suppressing means 118 are provided as new elements.

[0044] Here, the overshoot detection means 114 from the change trend of the heat exchanger temperature T _z, when the temperature T _z is beyond a predetermined amount or indeed T _zs time is expected to exceed the temperature set point T _zs determines that the occurrence of overshoot, the changing trend of overshoot converging detecting means 115 also heat exchanger temperature T _z, the temperature T when _z is predicted that does not exceed the temperature set point T _zs or indeed T _{When zs} falls below a predetermined amount, it is determined that the overshoot has converged. Differentiating means 116 detects the rate of change of the heat exchanger temperature T _z. Therefore, the overshoot suppressing means 117 instructs the ignition control means 102 to extinguish a fire when the overshoot occurs, and
For 0, set the fire extinguishing mode to instruct the stop of the combustion selection. Conversely, when the overshoot converges, the fire extinguishing mode is released. The heating amount inhibition means 118 when a large rate of change in the heat exchanger temperature T _z, reducing the feedback control amount F _B of the feedback calculation unit 108 on condition of release of the extinguishing mode.

With these controls, it is possible to prevent boiling due to a response delay caused by the feedback control.

FIG. 5 is a flowchart showing a processing procedure when the microcomputer has the functions of these control units. Hereinafter, a detailed operation of the boiling prevention control due to the control delay will be described with reference to this flowchart.

In the first step 151, it is determined whether or not the mode is the fire extinguishing mode. If the mode is not the fire extinguishing mode, the processing from the step 152 is executed. If the mode is the fire extinguishing mode, the processing from the step 163 is executed.

The running PI calculation on the deviation between the step 152 heat exchanger temperature T _z and the temperature set point T _zs seek feedback control amount F _B, followed by a feed forward control amount F ₀ in step 153 and the feedback adding the controlled variable F _B to determine the amount of heating F. Moreover, compared with the minimum opening F _{12 min} of heating amount F simultaneously burning time of the proportional valve 15 in Step 154, and executes step 155 following processing if there in _{F <F 12min, F <F} 12mi n Otherwise, ie, F ≧ F
_If it is 12 _min , the processing of step 157 and the following steps is executed.

In step 155, the first on-off valve 13 is opened. In step 156, the opening of the proportional valve 15 is controlled so that the heating amount F can be obtained by the single combustion of the first burner 11, and the following steps 159 and 159 are performed. In step 157, the first and second on-off valves 13 and 14 are both opened. In the next step 158, the heating amount F is obtained by simultaneous combustion of the first and second burners 11 and 12. Then, the opening degree of the proportional valve 15 is controlled, and the processing after step 159 is executed.

In step 159, it is determined whether or not overshoot has occurred. If so, fire extinguishing processing is executed in step 160. In step 161 the fire extinguishing mode is set and the processing is terminated. rate of change to be generated Te step 162 heat exchanger temperature T _z is equal to or greater than a predetermined value. If it is not large, the process is terminated. If it is large, the process proceeds to step 166.

On the other hand, if the fire extinguishing mode is determined in step 151, it is determined in step 163 whether or not the overshoot converges. If the overshoot does not converge, the process is terminated. If it is determined that converges, the fire extinguishing mode is canceled in step 164, and further, the first opening / closing valve 13 is opened in step 165 and the ignition operation is executed. Then, to reduce the feed-forward control amount F ₀ or feedback control amount F _B by a predetermined amount or predetermined ratio in step 166 and the process ends.

The function of each block shown in FIG. 4 can be realized by the above processing procedure.

[0053] Figure 6 shows the configuration of the heat exchanger temperature detector 25, when detecting piping temperature, as shown in FIG. 6 (a), if Ke attach the thermistor T _z on the outer surface of the pipe well, when detecting pipe water temperature, as shown in FIG. (b), so as to penetrate the pipe of the heat exchanger, it may be inserted a small diameter pipe equipped with a thermistor T _z the tip.

Thus, according to the present embodiment, the amount of heating can be increased as much as possible within a range in which the boiling water on the hot water supply side can be prevented from boiling during the heating of the bathtub water, whereby the bathtub water is quickly boiled. be able to.

Further, since the heating amount of the heating unit is controlled in accordance with the feedback control amount or the feedforward control amount, the heating amount can be increased to a point where the water retained in the hot water supply side heat exchanger does not boil.

Further, the control according to the feedforward control amount is performed at the start of heating, and the control according to the sum of the feedforward control amount and the feedback control amount during the steady heating heat is performed, so that finer control can be achieved. It becomes possible.

Further, when the occurrence of overshoot is detected, the heating section is extinguished, and when the change in the heat exchange temperature is large, the amount of heating of the heating section is suppressed, so that the heat exchange on the hot water supply side due to the response delay. Boiling of the water retained in the vessel can be reliably prevented.

On the other hand, since the heating section composed of the first and second heating sections is used, the range of proportional control is widened, and fine control can be performed.

[0059]

As is apparent from the above description, according to the present invention, the heating amount can be increased as much as possible within the range in which the boiling water staying on the hot water supply side can be prevented from boiling during the heating of the bathtub water. The effect that bathtub water can be boiled quickly is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.

FIG. 2 is a functional block diagram of one embodiment of the present invention.

FIG. 3 is a flowchart showing a processing procedure when a main element of one embodiment of the present invention is constituted by a microcomputer.

FIG. 4 is a functional block diagram of another embodiment of the present invention.

FIG. 5 is a flowchart showing a processing procedure when a main element of another embodiment of the present invention is constituted by a microcomputer.

FIG. 6 is an installation state diagram of main elements according to one embodiment of the present invention.

[Explanation of symbols]

 2 Fin 3 Hot water supply side heat exchanger 4 Reheating side heat exchanger 8 Bathtub 10 Circulation pump 11 First burner 12 Second burner 13 First on-off valve 14 Second on-off valve 15 Proportional valve 16 Fan 25 Heat exchange temperature detecting section

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Miura 43-1, Uozakihama-cho, Higashinada-ku, Kobe-shi, Hyogo Japan Inside Nippon Yupro Co., Ltd. (72) Inventor Shoji Inoue Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka Prefecture No. 1-1, Toto Kiki Co., Ltd. (56) References JP-A-4-236053 (JP, A) JP-A-61-101745 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) F24H 1/10 302 F24H 1/10 301

Claims (5)

(57) [Claims] 1. A hot water supply for heating a can body having a hot water supply side heat exchanger connected to a water supply pipe and a hot water supply pipe and a reheating side heat exchanger connected to a circulation water channel of bathtub water by a common heating unit. In the apparatus, while heating the bathtub water by the reheating-side heat exchanger, a heating amount control unit that controls a heating amount of the heating unit so as to bring the temperature of the hot water supply-side heat exchanger closer to a target value, The heating amount control means, a heat exchange temperature detection unit that detects a pipe temperature or a water temperature in the pipe of the hot water supply side heat exchanger, and a feedback calculation means that calculates a feedback control amount based on an output of the heat exchange temperature detection unit. A hot water supply apparatus comprising: a bathtub temperature detecting unit that detects a bathtub water temperature; and a feedforward calculating unit that calculates a feedforward control amount based on an output of the bathtub temperature detecting unit. 2. The heating amount control means further executes control according to the feedforward control amount at the start of heating, and performs control according to an added value of the feedforward control amount and the feedback control amount during steady-state heating. The hot water supply apparatus according to claim 1, further comprising a transition unit configured to execute: 3. The heating amount control means further includes an overshoot detection means for detecting that an overshoot has occurred in the water temperature in the pipe of the hot water supply side heat exchanger based on an output of the heat exchange temperature detection section. The hot water supply apparatus according to claim 2, further comprising: overshoot suppressing means for extinguishing the heating section based on an output of the overshoot detecting means. 4. The heating amount control means further comprises: a differentiating means for detecting a change in an output of the heat exchange temperature detecting section; and a heating amount of the heating section when an output of the differentiating means exceeds a predetermined value. The hot water supply apparatus according to claim 2, further comprising: a heating amount suppression unit that suppresses the heating amount. 5. The heating section comprises first and second heating sections, and the heating amount control means further controls one or both of the first and second heaters in accordance with a heating amount. 2. The apparatus according to claim 1, further comprising means for selecting a heating unit.
A hot water supply apparatus according to any one of claims 1 to 4.