JP3006210B2 - Water heater control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater with a bath kettle of a one-can-two-channel type.

[0002]

2. Description of the Related Art A conventional control device of this kind is, for example, shown in FIG.
As shown in FIG. 1, the heat exchanger 1 has a heat transfer tube 2 for hot water supply and a heat transfer tube 3 for post-bath heating. Then, the heat exchanger 1 is heated by the burner 4. Reference numeral 5 denotes a fuel control valve for sending fuel (gas) to the burner 4, and reference numeral 6 denotes an igniter for igniting the burner 4.
The heat transfer pipe 2 is provided with a hot water temperature detecting means (thermistor, etc.) 7 for detecting the temperature of the hot water and a hot water supply switch 8 for detecting the flow of water in the heat transfer pipe 2. The heat transfer tube 3 for bath reheating is provided with a bath temperature detecting means (thermistor or the like) 9 for detecting the temperature of flowing hot and cold water, and a circulation pump 11 for heating and circulating the water in the bathtub 10. Reference numeral 12 denotes an operation controller for setting hot water temperature / bath temperature, turning on / off reheating, and the like, and 13 receives a hot water / bath control signal from the operation controller 12, and supplies hot water temperature detection means 7 and bath temperature detection means. 9, the hot water supply temperature and the bath temperature are input, and the igniter 6 and the fuel control valve 5 are operated in a predetermined procedure, and the burner 4
This is a hot-water supply bath control means for controlling the ignition and the combustion amount, and operating the circulation pump 11 to heat and circulate the water in the bathtub 10 at the time of reheating. Reference numeral 14 denotes a curran provided at the end of the heat transfer pipe 2 for hot water supply. With this configuration,
When the curan 14 is opened or when the operation controller 12 is turned on from the reheating off, the hot water supply bath control means 13
Has transmitted a control signal to the igniter 6 and the fuel control valve 5 in accordance with the above-mentioned predetermined procedure, controlled the heating by the burner 4, and performed a predetermined hot water supply and a predetermined bath temperature heating circulation to the bathtub water.

[0003]

However, in the above-described configuration, the bath reheating operation and the hot water supply operation are independently operated, or the bath reheating is stopped uniformly. Therefore, the method of uniformly stopping the reheating of the bath unnecessarily restricts the reheating operation and makes the use worse. In addition, the method in which the bath reheating and hot water supply operation are operated independently is to output the total value of the required combustion amount of each when simply shifting to the simultaneous operation during the bath reheating or hot water supply operation. In the non-operating side of the heat transfer tube of the one-can-two-channel heat exchanger 1, hot water stays and is in a so-called post-boiling state. If the amount is reduced, the stagnant water is further heated, and high-temperature hot and cold water is discharged, and there is a problem that a danger such as a burn may occur.

The present invention solves the above-mentioned conventional problems. When the hot water supply unit shifts from the single operation of the bath reheating operation and the hot water supply operation to the simultaneous operation, the transfer of the heat exchanger on the non-operation side during the single operation is performed. Provided is a hot water supply system that can shift to simultaneous operation without reheating heated water in a heat pipe and without an abnormally high temperature hot water supply, and has improved hot water supply characteristics with small fluctuations in hot water temperature and improved usability by expanding a bath reheating operation range.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a control device for a water heater according to the present invention comprises a one-can-two-channel heat exchanger integrally having a heat transfer tube for hot water supply and a heat transfer tube for bath heating. , A burner that heats this, a circulation pump that transports hot water from the heat transfer tube for bath heating to the bathtub, an input water temperature detection means that detects the temperature of incoming water supplied to the heat transfer tube for hot water, and a supply to the heat transfer tube for hot water The required amount of combustion on the hot water supply side in the burner is calculated from the flow rate detecting means for detecting the supplied water amount, the hot water temperature setting means for setting the hot water temperature, the incoming water temperature detecting means, the flow rate detecting means and the hot water temperature setting means. And, at the time of transition from bath reheating or hot water supply alone operation to simultaneous operation of bath reheating and hot water supply, from the combustion amount in each individual operation to the total combustion amount of the hot water supply side combustion amount and the predetermined bath reheating combustion amount To switch Those having a combustion amount control means for a constant time delay.

[0006]

According to the present invention, the combustion amount control means uses a predetermined bath reheating combustion amount and an incoming water temperature after a delay of a predetermined time when the bath water heating operation or the hot water supply operation shifts from the single operation to the simultaneous operation. By outputting the total combustion amount of the required combustion amount on the hot water supply side calculated by the detection means, the flow rate detection means, and the hot water supply temperature setting means, abnormal high-temperature hot water supply is suppressed, and the fluctuation of the hot water supply temperature is reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. The same members as those in FIG. 4 of the conventional example are denoted by the same reference numerals. FIG. 1 is a control configuration diagram of the water heater of the present invention. 15 is an incoming water temperature detecting means for detecting the incoming water temperature supplied to the hot water supply heat transfer pipe 2, 16 is a flow rate detecting means for detecting an amount of supplied water to the hot water supply heat transfer pipe 2, and 17 is an incoming water temperature detecting means 15 And the incoming water temperature and flow rate from the flow rate detecting means 16, and the hot water supply set temperature from the operation controller 12 as hot water temperature setting means, respectively, to calculate the required combustion amount for hot water supply, and to supply hot water and bath water At the time of simultaneous use, the combustion amount of the hot water supply plus the required combustion amount for the additional bath reheating is defined as the required combustion amount of the burner, and the switching to the total required combustion amount is delayed by a predetermined amount by combustion amount control means. is there. Further, the combustion amount control means 17 receives the reheating operation signal from the operation controller 12 and a set temperature signal such as a bath set temperature, and sends the combustion control signal to the fuel control valve 5 by the delay means 18 and the delay switching means. It is connected so as to output an ignition drive signal to the igniter 6 and to output a drive control signal to the circulation pump 9 via the igniter 6.

The operation of the above configuration will be described with reference to a flowchart shown in FIG. 2 and a time chart shown in FIG.

In FIG. 2, when the hot water supply is used alone, the combustion amount control means 17 detects the opening of the curan 14 by the flow rate detection means 16 (s1), and determines whether or not the operation controller 12 has performed an operation of reheating the bath. (S2) is checked (whether the reheating switch (not shown) is turned on). If there is no bath reheating operation, the amount of supplied water (FL) supplied to the heat transfer pipe 2 for hot water supply, the incoming water temperature (THI) detected by the incoming water temperature detecting means 15, and the set hot water supply temperature set by the operation controller 12 ( TS), a required combustion amount (QGI) for hot water supply is obtained from the following equation, and a combustion amount output corresponding to the required combustion amount (QGI) is output to the fuel control valve 5.

QGI = (TS−THI) × FL ÷ K (1) K is the hot water supply efficiency (s3). If the bath reheating switch is not turned on, the circulation pump 11 is turned off (s4). Usually, it operates in this state at the time of hot water supply independent operation.

If the bath reheating switch is turned on during the hot water supply alone operation, first, the combustion amount control means 17 checks whether or not a predetermined delay time (td seconds) has elapsed (s5). If the delay time has not elapsed, the combustion amount is output with the required combustion amount (QGI) for hot water supply alone. Delay time (td
Seconds), a predetermined combustion amount (Q) determined in advance by the bath temperature detected by the bath temperature detecting means 9.
GF) is added to the required combustion amount (QGI) of the hot water supply to obtain a total required combustion amount (QGW) from the following equation, and further, a combustion amount output corresponding to the required combustion amount (QGW) is obtained by the fuel control valve 5. Is output to (s6).

QGW = QGI + QGF (2) At this time, the circulation pump 11 is turned on (s7).

[0013] During the reheating alone operation, the operation controller 12 checks whether or not the bath reheating switch is turned off (s8). When the bath reheating switch is turned off, the circulation pump 11 is turned off to stop the combustion (s9, s10). If the bath reheating switch is not turned off, the flow rate detecting means 16 checks whether or not the curan 14 has been opened (s11). If the curan 14 has not been opened, a combustion amount output corresponding to a predetermined combustion amount (QGF) predetermined by the bath temperature detected by the bath temperature detecting means 8 is output to the fuel control valve 5 (s12). .

In this state, if the opening of the curan 14 is detected by the flow rate detecting means 16, first, the combustion amount control means 17 determines a predetermined amount in the same manner as when the hot water supply is used alone and the hot water supply bath is used simultaneously. It is checked whether or not the delay time (td second) has elapsed (s13). If the delay time has not elapsed, the required combustion amount (QG
F) Output combustion amount as it is. If the delay time has elapsed, the total required combustion amount (QG) obtained by adding the required combustion amount (QGI) of the hot water supply to the combustion amount (QGF) in the bath reheating alone operation.
W) is obtained in the same manner as in the above-described arithmetic expression, and a combustion amount output corresponding to the combustion amount (QGW) is output to the fuel control valve 5 (s1).
4).

FIG. 3 shows the time characteristics of the hot water supply flow rate (a), the combustion amount (b), and the hot water supply outlet temperature (c) in the case of simultaneous operation using hot water supply after the single heating operation.

In FIG. 3 (a), at t = t1, the curran 1
4 is opened, and the hot water supply flow rate (F1) is detected by the flow rate detection means 16. The change in the combustion amount is Q1 = until t = t1.
The output is QGF, and the output is maintained until t2 after td from t1. Q2 = QGF + Q at t = t2
The output changes to the GW output. For this reason, as shown in FIG. 3 (c), the hot water supply-side outlet temperature is different from the hot water supply-side outlet temperature characteristic (c1) in FIG.
It becomes like the hot water supply side tapping temperature characteristic (c2) when there is a delay. This is because the amount of combustion corresponding to Q2 was changed after the high-temperature water stored in the hot water supply tube when the bath was used alone flows out of the hot water supply tube.

In either case of using the hot water supply alone or simultaneously using the hot water supply bath, the so-called PID control (so-called PID control) is performed by the hot water temperature detection means 7 so that the hot water supply temperature becomes the hot water supply set temperature from the operation controller 12. By performing the feedback control), the hot water supply tap temperature deviation at the time of outputting the combustion amount corresponding to the above-described hot water supply combustion amount (QGI) and the total required combustion amount (QGW) is corrected.

Therefore, at the time of transition from the single operation of the bath water heating operation or the hot water operation to the simultaneous operation of the water heater, after a predetermined time delay, a predetermined bath water heating (QGW) and the incoming water temperature detecting means 15 are provided. By outputting the total combustion amount (QGW) of the required amount of combustion (QGI) on the hot water supply side calculated by the flow rate detecting means 16 and the hot water supply temperature setting means 12, fluctuations in the hot water supply temperature with abnormally high temperature hot water supply are reduced. Will be done.

In the above-described embodiment, even when the hot water supply operation shifts from the single operation of the hot water supply operation to the simultaneous operation of the hot water supply and the additional heating, after a predetermined time delay, the predetermined bath additional heating combustion amount and the hot water supply Although the total combustion amount of the required combustion amount is output,
Actually, there is a detection delay time in which the circulating pump is operated to detect flowing water in the circulating flow path by a flowing water switch (not shown) or the like. Even if it is changed, the same effect can be obtained.

[0020]

As described above, according to the control device of the water heater of the present invention, when shifting from the single operation of the bath water heating operation and the hot water supply operation to the simultaneous operation of the two operations, the non-operation of the single water operation is performed. Without reheating the water remaining in the heat transfer tubes of the heat exchanger on the operating side,
The operation can be shifted to the simultaneous operation without an abnormally high temperature hot water supply, and the hot water temperature characteristic can be stabilized.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control device of a water heater in one embodiment of the present invention.

FIG. 2 is a flowchart showing operating characteristics of the control device.

FIG. 3 is a time chart showing time characteristics of the control device.

FIG. 4 is a control block diagram of a conventional water heater control device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 heat exchanger 2 heat transfer tube for hot water supply 3 heat transfer tube for hot water bath 4 burner 11 circulation pump 12 hot water supply temperature setting means 15 incoming water temperature detection means 16 flow rate detection means 17 combustion amount control means

──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Masaatsu Inoue 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. In-house (56) References JP-A-62-37636 (JP, A) JP-A-3-247951 (JP, A) JP-A-3-48652 (JP, U) JP-A-2-140254 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F24H 1/00 602-604

Claims (1)

(57) [Claims] 1. A heat exchanger, a burner for heating the heat exchanger, a heat transfer tube for hot water supply and a heat transfer tube for bath reheating provided in the heat exchanger, and a bathtub from the heat transfer tube for reheating bath A circulating pump for transporting hot water, an incoming water temperature detecting means for detecting an incoming water temperature supplied to the hot water supply heat transfer pipe, a flow rate detecting means for detecting an amount of water supplied to the hot water supply heat transfer pipe, and a hot water supply temperature The required amount of combustion on the hot water supply side is calculated from the hot water supply temperature setting means, the incoming water temperature detection means, the flow rate detection means, and the hot water supply temperature setting means, and the hot water supply and the hot water supply operation are performed from the hot water supply or the hot water supply alone operation. And a combustion amount control means for delaying switching from a combustion amount in each of the individual operations to a total combustion amount of the hot water supply side combustion amount and the predetermined bath post-burning combustion amount for a predetermined time when shifting to the simultaneous operation of heating. Water heater control device.