JP3079905B2 - Water heater operation 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 operation control device.

[0002]

2. Description of the Related Art Conventionally, in a water heater in which water from a water supply or the like is guided from an inlet pipe to an instantaneous heat exchanger heated by a burner and is supplied to a tapping pipe, at least feedforward control is performed as an operation control method. Since the calculation of the required amount of combustion heat of the burner is calculated from the incoming water temperature, the incoming water flow rate, and the set outlet temperature, the required amount of combustion heat cannot be calculated if the incoming water temperature sensor or the like fails. , The operation of the apparatus was stopped. Also,
Japanese Utility Model Application Publication No. Sho 61-181942 pertaining to the applicant of the present application discloses that in a water heater that performs feedforward control and feedback control, when the incoming water temperature sensor fails, the operation is performed only by feedback control, and the outlet temperature sensor is There is provided an operation control device that operates only by feedforward control when a failure occurs.

[0003]

However, in the case where the operation is stopped when the above-mentioned incoming water temperature sensor or the like breaks down, there is a drawback that it cannot be used until it can be repaired. Further, in the case of the above-mentioned Japanese Utility Model Application Laid-Open No. 61-181942, if the incoming water temperature sensor fails, only feedback control is performed, so it takes time to adjust the outgoing water temperature to a predetermined set temperature, Can not be expected to have a favorable temperature.

Therefore, the present invention solves the above-mentioned drawbacks of the prior art, so that even if the incoming water temperature sensor fails, emergency operation can be performed without stopping the apparatus, and feedforward control can be continued. An object of the present invention is to provide an operation control device for a water heater that can quickly adjust to a predetermined set tapping temperature and tap water.

[0005]

In order to achieve the above object, an operation control apparatus for a water heater according to the present invention guides water from a water supply or the like to an instantaneous heat exchanger which is heated from a water inlet pipe by a burner. In addition to tapping water into the pipe, the inlet pipe is provided with an incoming water temperature sensor and an incoming water flow rate sensor, and the outgoing pipe is provided with an outgoing water temperature sensor. An operation control device for a water heater, wherein the burner is feedback-controlled based on an obtained tapping temperature and a set tapping temperature while performing feedforward control on the burner, wherein the inlet temperature sensor has failed. In this case, a controller is provided for performing a feedforward control by displaying a failure and calculating a required amount of combustion heat using the incoming water temperature before the failure.

[0006]

According to the above-mentioned feature of the present invention, when the incoming water temperature sensor fails, a failure is displayed by the controller. Further, the controller calculates the provisional required combustion heat of the burner from the input water temperature before failure stored by itself, the input water flow rate and the set tap water temperature, and performs provisional feedforward control on the burner. . Of course, normal feedback control is also performed in addition to the provisional feed forward control. The incoming water temperature changes according to the season and the like.However, since the incoming water temperature does not suddenly greatly change during the previous operation and the present operation, the provisional feedforward control and the normal feedback control are usually performed. In particular, even if the operation is performed by the method described above, no problem occurs, and the tapping characteristics in the early stage of tapping are particularly improved as compared with the case where only the feedback control is performed. Of course, the operation of the apparatus is not stopped and the apparatus cannot be used.

[0007]

1 is an overall configuration diagram of a water heater showing an embodiment of the apparatus of the present invention, and FIG. 2 is a flowchart for explaining a control mechanism of a controller.

In FIG. 1, reference numeral 10 denotes a water inlet pipe, and water from a water supply or the like is guided to an instantaneous heat exchanger 20 through the water inlet pipe 10, heated and discharged to a hot water outlet pipe 30. The water inlet pipe 10 is provided with an incoming water temperature sensor 11 and an incoming water flow rate sensor 12.
The tapping pipe 30 is provided with a tapping temperature sensor 31 and an overflow prevention regulator 32. The instantaneous heat exchanger 20 is heated by the burner 40, so that water passing through the inside of the instantaneous heat exchanger 20 is heated. The burner 40 is, for example, a gas burner, and the gas fuel passed through the gas solenoid valve 42 of the gas supply pipe 41 is supplied to the burner 40 with the gas amount adjusted by the proportional valve 43.
44 is a blower fan.
Done by That is, the controller 50 has a built-in microcomputer and inputs information from each of the sensors 11, 12, and 31,
In addition, based on a driving instruction from the remote controller 51, etc.,
A predetermined calculation for control is performed, and a predetermined control command is output to the burner 40 and its auxiliary equipment 42, 43, 44 and the like.

The control mechanism of the controller 50 will be further described with reference to FIG. 2. When a hot water tap (not shown) is opened and the incoming water temperature sensor 11 detects the minimum working water amount or more, the controller 50 controls the burner 40. Prior to this, the controller 50 determines whether the tap water temperature thermistor serving as the tap water temperature sensor 31 and the incoming water temperature thermistor serving as the incoming water temperature sensor 11 are normal (S1). , S2). The determination is, for example, that each of the tap water temperature sensor 31 and the incoming water temperature sensor 11 is in a failure state if they are in an open (disconnected) state or a short-circuit state. If both the hot water temperature sensor 31 and the incoming water temperature sensor 11 are normal (Yes in S1 and Yes in S2), the controller 50 operates the incoming water temperature sensor.
The incoming water temperature from 11 is stored (S3), and combustion of the burner 40 is commanded (S4). The controller 50 calculates the required combustion heat of the burner 40 from the incoming water temperature and the set outgoing water temperature by the incoming water temperature sensor 11 and the incoming water flow rate by the incoming water flow rate sensor 12, and feeds forward control (FF control) the combustion of the burner 40. At the same time, the combustion of the burner 40 is feedback-controlled (FB control) based on the tapping temperature actually detected by the tapping temperature sensor 31 and the set tapping temperature (S).
5). The storage of the incoming water temperature may store the latest one normally detected by the incoming water temperature sensor 11, or the first one detected at the beginning of operation after the incoming water temperature sensor 11 is determined to be normal. You may make it memorize | store.

On the other hand, when the tapping temperature sensor 31 is normal (S1
And the input water temperature sensor 11 fails (No in S2).
In the case of (1), the controller 50 displays a failure of the incoming water temperature sensor 11 on the display unit of the remote controller 51 or the like (S6), and instructs the burner 40 to burn (S7). In this case, the controller 50 uses the input water temperature before the failure of the input water temperature sensor 11 stored therein to determine the provisional required combustion heat of the burner 40 from the stored input water temperature, the input water flow rate, and the set outlet water temperature. Calculation and provisional feedforward control (temporary FF control) for the burner 40, and a tapping temperature sensor
Feedback control (FB control) of the combustion of the burner 40 is performed based on the hot water temperature actually detected by 31 and the set hot water temperature (S8). The provision of the provisional feedforward control means that the feedforward control is performed using the provisional necessary heat of combustion, and the feedforward control itself is not particularly special. Even when using the incoming water temperature before the incoming water temperature sensor 11 fails, usually
Since the incoming water temperature does not change abruptly, the provisional feedforward control can be performed in a state sufficiently similar to the feedforward control to be performed using the actual incoming water temperature.

When the tapping temperature sensor 31 is out of order (No in S1), the controller 50 does not perform the feedback control but performs only the feedforward control to adjust the tapping temperature (S9). Of course, also in this case, the failure display of the tapping temperature sensor 31 is displayed on the display unit of the remote controller 51 or the like. Further, when the incoming water temperature sensor 11 is also out of order, the feedforward control by the controller 50 is, of course, provisional feedforward control.

[0012]

According to the present invention, the operation control apparatus for a water heater according to the first aspect of the present invention provides a display of a failure when the input water temperature sensor fails, and a display for displaying the failure before the failure occurs. Since the controller for performing the feedforward control by calculating the required amount of combustion heat using the incoming water temperature is provided, even if the incoming water temperature sensor fails, the emergency operation can be performed without stopping the apparatus. Moreover, although the inlet water temperature before the failure is changed, the inlet water temperature changes according to the season and the like, but usually the inlet water temperature does not suddenly change greatly between the previous operation and the current operation. After all, even in the feedforward control using the temporary value, an effect sufficiently similar to the feedforward control to be performed on the actual incoming water temperature can be obtained. Therefore, by performing the control based on the combination of the provisional feedforward control and the feedback control, it is possible to perform hot water supply with sufficiently good tapping characteristics, especially in the initial stage of tapping, as compared with the case where only the feedback control is used.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a water heater showing an embodiment of the device of the present invention.

FIG. 2 is a flowchart illustrating a control mechanism of a controller.

[Explanation of symbols]

 10 Inlet pipe 11 Inlet temperature sensor 12 Inlet flow rate sensor 20 Instantaneous heat exchanger 30 Outlet pipe 31 Outlet temperature sensor 40 Burner 50 Controller

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoji Hata 32, Akashi-cho, Chuo-ku, Kobe-shi, Hyogo Pref. (56) References JP-A-4-136612 (JP, A) JP-A-61-181942 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F23N 5/02 350 F23N 5 / 24 113 F24H 1/10 302

Claims (1)

(57) [Claims] 1. A water supply system for guiding water from a water inlet or the like to an instantaneous heat exchanger heated by a burner from a water inlet pipe to supply water to a hot water outlet pipe. The water inlet pipe is provided with an incoming water temperature sensor and an incoming water flow rate sensor. Provided, a tapping temperature sensor is provided in the tapping pipe,
A water heater that calculates the required amount of combustion heat from the incoming water temperature, the incoming water flow rate, and the set outlet temperature, feed-forward controls the burner, and performs feedback control of the burner based on the obtained outlet temperature and the set outlet temperature. An operation control device, wherein a controller is provided for performing a feedforward control by performing a failure display when the incoming water temperature sensor fails and calculating a required amount of combustion heat using the incoming water temperature before the occurrence of the failure. An operation control device for a water heater.