JP2000111158A - Hot water supply apparatus with heat insulating function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform heat insulation control in safety by previously setting a plurality of heat insulation temperatures depending on the water temperature in an apparatus and switching the heat insulation temperature depending on the water temperature in an apparatus detected by a water temperature detecting means thereby suppressing hydraulic pressure rise incident to heat insulation combustion. SOLUTION: When a water quantity sensor 8 in a hot water supplier 1 detects water passed through an apparatus by opening a faucet coupled with a hot water delivery pipe 6, a controller 10 opens a main solenoid valves 11, 13 and actuates an igniter to cause continuous spark of an ignition electrode 16. At the same time, a proportional control valve 12 is opened by a specified opening and a burner 4 is ignited. Subsequently, the controller 10 operates a required heating quantity based on an initial water temperature received from a supply water temperature 7 such that hot water is delivered at a temperature set by the adjusting button of a remote controller 14. Thereafter, opening of the proportional control valve 12 is adjusted and corrected such that the delivery hot water temperature matches with the set temperature based on a detection temperature from a delivery hot water sensor 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to heating of a heat exchanger by combustion of a burner in a water-stop state when the temperature of the heat exchanger is reduced to a predetermined temperature due to the heat radiation state of the equipment, and the water temperature in the equipment is maintained at a predetermined temperature. The present invention relates to a water heater with a heat retention function capable of executing a heat retention control to be maintained.

[0002]

2. Description of the Related Art In general, a water heater is supplied with water by opening a faucet provided on a tapping side of the appliance, and when a water quantity sensor detects the water, a burner is ignited and a heat exchanger is activated. By heating the passing water and supplying hot water of a predetermined temperature, the faucet is closed and the flow of water in the appliance stops, and when this is detected by the water amount sensor, the burner is extinguished and the operation of the appliance stops. Has become. In such a water heater, the water stored in the appliance at the start of use is sent out, and it takes time to rise the tap water temperature. Each time the water is burned at a predetermined interval, the temperature of the water in the appliance is maintained at a predetermined temperature (for example, 30 minutes).
° C), and when a water heater is used, a hot water supply at a set temperature is obtained at a rapid rise to provide a heat retaining function for improving usability.

[0003]

However, the intermittent combustion up to the heat retention temperature is repeated irrespective of the temperature of the water stored in the appliance. Therefore, if the water temperature in the appliance is too low, the amount of heating increases accordingly. . Specifically, as shown in FIG. 5, when the water temperature in the appliance is 20 ° C., in order to raise the temperature to 30 ° C. or higher, only two heatings are required at 5 minute intervals (upper graph). When the internal water temperature is 12.6 ° C, 3 at 5 minute intervals
One heating cycle is required (lower graph). For this reason, the water pressure in the appliance is 4.5 kg / cm ² when the water temperature in the appliance is 20 ° C.
To 10 kg / cm ² , but when the water temperature in the appliance is 12.6 ° C., the water pressure is from 4.5 kg / cm ² to 12.
It rises to 6 kg / cm ^{2, and} there is a possibility that it will blow out from the pressure relief valve. In particular, when the water temperature in the appliance becomes 10 ° C. or lower, the number of times of heating is further increased, so that the water pressure is further increased.

Accordingly, an object of the present invention is to provide a water heater with a heat retaining function capable of suppressing a rise in water pressure due to such heat retaining combustion and performing a heat retaining control safely.

[0005]

In order to achieve the above object, according to the present invention, there is provided a water temperature detecting means for detecting a water temperature in the appliance, and the water temperature detecting means according to the water temperature in the appliance is provided. A plurality of preserving temperatures are set in advance, and the preserving control is executed by switching the preserving temperature in accordance with the water temperature in the appliance obtained by the water temperature detecting means.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a water heater with a heat retention function (hereinafter abbreviated as “water heater”), in which a water heater 1 is connected to a water supply pipe 3 connected to an inner body 2 forming a combustion chamber therein. A heat exchanger 5 for heating water with the combustion heat of the burner 4 is provided.
Is connected. The water supply pipe 3 is provided with an incoming water temperature sensor 7 as an incoming water temperature detecting means for detecting the temperature of the water passing through the water supply pipe 3 and a water quantity sensor 8 for detecting the flow rate of the water. A tap water temperature sensor 9 for detecting a temperature of water passing through the pipe 6 is provided, and a detection signal of each sensor is input to a controller 10. In the gas flow path to the burner 4,
From the upstream side, an original solenoid valve 11, a proportional control valve 12, and a main solenoid valve 13 are provided, respectively.
Opening / closing is controlled by 0. Further, the controller 10 includes a remote controller 14 including an operation switch, a set temperature adjustment button, a heat insulation switch 15 for heat insulation control, an ignition electrode 16 for ignition of the burner 4, and a flame rod 17 for flame detection. It is connected.

Therefore, in the water heater 1, when the water flow sensor 8 detects the water flow through the appliance by opening a faucet (not shown) connected to the tapping pipe 6, the controller 10 returns to the original solenoid valve. 11 and the main solenoid valve 13 are respectively opened, and an igniter (not shown) is operated to
6, the proportional control valve 12 is opened at a predetermined opening, and the burner 4 is ignited. Thereafter, the controller 10 calculates the required heating amount from the initial water temperature obtained from the incoming water temperature sensor 7 so that the hot water is discharged at the set temperature set by the adjustment button of the remote controller 14, and the opening of the proportional control valve 12. Is adjusted, and the opening of the proportional control valve 12 is corrected and controlled based on the detected temperature obtained from the tapping temperature sensor 9 so that the tapping temperature matches the set temperature.

FIG. 2 is an explanatory view showing a flow path of the heat absorbing tube in the heat exchanger 5. In this example, the water temperature detecting means is provided near the downstream side of the heat absorbing tube B immediately above the burner 4. A temperature sensor 18 such as a thermistor is provided.
Is turned on, the burner 4 is burned for a few seconds with a predetermined input while keeping water in the appliance in a water-stop state, based on the water temperature in the appliance obtained from the temperature sensor 18, and the heat is released from the appliance. The temperature control is performed according to the temperature drop caused by the temperature control, and the heat retention control for keeping the water temperature in the appliance at a constant temperature can be executed. Hereinafter, this heat retention control will be described with reference to the flowchart of FIG. First, when the heat retention switch is turned on in S1, it is determined in S2 whether the appliance water temperature obtained from the temperature sensor 18 is 10 ° C. or higher. If it is 10 ° C or more,
In S3, the intermittent insulated combustion is performed at the above-described 5-minute intervals. Here, if the water temperature in the appliance reaches 27 ° C. or more in S4, the insulated insulated combustion is stopped in S5. On the other hand, if the water temperature in the appliance is less than 10 ° C. in the determination in S2, the same heat-retention combustion as in S4 is executed in S6. However, if the water temperature in the appliance reaches 20 ° C. or more in S7, the heat retention is performed in S8. Combustion will be stopped.

As described above, the water temperature in the appliance before the insulated combustion is 1
By switching the heat retention temperature between 27 ° C. and 20 ° C. depending on whether it is 0 ° C. or more, as shown in FIG. 4, when the water temperature in the appliance is 10 ° C. or more, for example, 13.1 ° C. (upper graph) (upper graph), twice. Reaches 27 ° C or more with the number of heating times, and the water pressure in the appliance is 4.5 kg
/ Cm ² to 10.0 kg / cm ² .
In addition, when the water temperature in the appliance is lower than 10 ° C., for example, 5 ° C. (lower graph), the temperature reaches 20 ° C. or more by two heating times, and the water pressure in the appliance is from 4.5 kg / cm ² to 10.0 kg /. stay to the increase of up to cm ^2. Therefore, according to the water heater 1, the pressure rise in the appliance due to the heat retention combustion is suppressed and the safety is preferentially ensured, and the maximum heat retention effect is obtained to contribute to the shortening of the rising time at the time of hot water supply. It is possible to achieve a well-balanced heat retention control. Further, since a temperature sensor 18 provided near the downstream side of the heat absorbing tube B in the heat exchanger 5 is used as a water temperature detecting means in the appliance, a temperature change due to heating of the burner 4 is detected sensitively, It is possible to accurately detect the temperature of the water inside.

[0010] The heat retaining temperature according to the water temperature in the appliance is not limited to the above-mentioned mode of switching between two types at 10 ° C.
If the temperature is lower than 27 ° C., the heat retention temperature may be set to 27 ° C., and if 27 ° C. or higher, the heat retention combustion may not be performed.
Although the temperature sensor 18 in the heat exchanger 5 is used as the water temperature detecting means here, the temperature sensor 18 is omitted,
The detected temperature obtained from the hot water temperature sensor 9 can be used as it is as the water temperature in the appliance for heat retention control. In this case, although the accuracy of grasping the water temperature in the appliance is slightly lower than that of the temperature sensor 18, it is possible to achieve the rationalization of the configuration and the cost reduction by sharing parts.

[0011]

According to the first aspect of the present invention, the heat retention control is executed by switching the heat retention temperature in accordance with the water temperature in the appliance obtained by the water temperature detecting means, so that the pressure in the appliance accompanying the heat retention combustion is obtained. While suppressing the rise and ensuring safety with priority, it is possible to achieve a well-balanced heat retention control that can obtain the maximum heat retention effect and contribute to shortening the rising time at the time of tapping.

[Brief description of the drawings]

FIG. 1 is a schematic view of a water heater with a heat retaining function.

FIG. 2 is an explanatory diagram showing a water flow path of a heat absorbing tube in a heat exchanger.

FIG. 3 is a flowchart of heat retention control.

FIG. 4 is a graph showing the relationship between the time required for warm combustion and the water temperature in the appliance.

FIG. 5 is a graph showing the relationship between the time required for keeping warm combustion of a conventional water heater and the water temperature in the appliance.

[Explanation of symbols]

1. Hot water heater with heat retention function, 2. Inner body, 3. Water pipe,
4 ・ ・ Burner 、 5 ・ ・ Heat exchanger 、 6 ・ ・ Hot water pipe 、 7 ・ ・
Water temperature sensor, 10 controller, 14 remote controller, 15 heat switch, 18 temperature sensor.

Claims (1)

[Claims] 1. Heating control of a heat exchanger by burning a burner in a water-stopped state when the temperature of the heat exchanger is reduced to a predetermined temperature due to a heat radiation state of the appliance, and maintaining a water temperature in the appliance at a predetermined insulation temperature. A possible water heater with a heat retaining function, wherein a water temperature detecting means for detecting a water temperature in the appliance is provided, and a plurality of the heat retaining temperatures according to the water temperature in the appliance are set in advance, and the water temperature detecting unit A water heater with a heat retention function, wherein the heat retention control is executed by switching the heat retention temperature according to the obtained water temperature in the appliance.