JPS63213720A - Safety device for hot-water supplier - Google Patents

Abstract

PURPOSE:To permit the detection of an abnormality in air-fuel ratio surely, by a method wherein a case where a condition that a hot-water delivery temperature is higher than the set temperature of supplying hot-water by a given temperature or more is continued for a given period of time or more, is detected as abnormality. CONSTITUTION:When the set temperature of supplying hot-water is set in a temperature setter 41 and hot-water supply is started, the necessary amount of combustion heat per unit time is operated in a controller 31 from the amount of input water, detected by an input water amount detecting sensor 4, an input water temperature, detected by an input water temperature detecting sensor 5, and the set temperature of supplying hot-water; then, the controller 31 commands a proportional control valve 17 to be opened to a necessary opening degree and commands a fan 21 to obtain the necessary amount of air, with the result that combustion is started. After the combustion is started, the controller 31 operates a difference between an actual output hot-water temperature and the set temperature of supplying hot-water at all times. When the output hot-water temperature is higher than the set temperature by a given temperature or more, the time in such a condition is counted. When the time has exceeded a given time, it is decided that the condition is abnormal; a solenoid opening and closing valve 12 is closed by the controller 31 while an informing means 51 is operated.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a safety device for water heaters, specifically, a combustion burner is provided with a fuel return circuit, and by adjusting the flow rate through the return circuit, the set hot water temperature can be adjusted. The present invention relates to a safety device for preventing abnormal combustion, etc. for a water heater that automatically sets burner combustion corresponding to the following conditions.

<Prior art> A nozzle-type combustion burner is equipped with a fuel return circuit, and by adjusting a proportional control valve provided in the return circuit, the amount of combustion is automatically adjusted. As a water heater for supplying hot water, a device described in, for example, Japanese Unexamined Patent Publication No. 149527/1983 has been provided.

<Problems to be Solved by the Invention> In conventional water heaters equipped with a proportional control valve in the return circuit, the proportional control valve is easily clogged with dirt, and as a result, the amount of fuel supplied relative to the air is abnormally large ( There was a problem with combustion abnormalities such as "burning", and the problem was that hot water temperature control could not be properly controlled due to this.

In order to eliminate such drawbacks, a configuration has also been proposed in which a pressure sensor is provided in the return circuit on the way from the combustion burner to the proportional control valve, and an abnormality is detected by the pressure sensor.

However, a water heater equipped with a safety device using a pressure sensor has the problem of high cost.

<Purpose> Therefore, the present invention aims to eliminate the drawbacks of the above-mentioned prior art and provide a water heater safety device that can reliably detect air-fuel ratio abnormalities without using expensive parts such as pressure sensors. do.

<Means for Solving the Problems> The present invention provides a heat exchange can, a combustion burner for heating the nuclear heat exchange can, and a method for heating the nuclear heat exchange can without using part of the fuel sent to the combustion burner. A safety device for a water heater, which is equipped with a return circuit for returning hot water to the temperature, and automatically eliminates the difference between the set hot water temperature and the actual hot water temperature by combustion ff1t1 clause by operating a proportional control valve provided in the return circuit. The system is characterized in that if the outlet temperature remains higher than the supply temperature by a certain temperature or more for a certain period of time or more, this is detected as an abnormality.

In order to solve the above problem, the inventors of the present invention conducted various comparative studies between the operating conditions under normal conditions and the operating conditions when the proportional control valve is clogged with dust. While the difference from the actual hot water temperature only appears within the standard variation of input (heat of combustion),
It was discovered that when the water is clogged with debris, the input becomes abnormally excessive and the actual hot water temperature rises significantly compared to the hot water supply setting temperature. In other words, for example, if the hot water supply temperature is set to 40℃, the actual hot water temperature will drop to 70℃ in the event of an abnormality.
The temperature rises to about ℃.

Therefore, the inventors of the present invention determined the difference between the hot water supply temperature setting and the actual hot water outlet temperature, and if the difference by a certain amount continues for a certain period of time or more, this is detected as an abnormality.

<Function> Since the temperature from the temperature sensor installed in the hot water outlet section can be compared with the hot water supply setting temperature, abnormalities can be detected using the controller of the proportional control valve as is, and special parts such as pressure sensors can be used. There is no need to add it to the return circuit.

<Example> FIG. 1 is an overall configuration diagram of an implementation device of the present invention, and FIG. 2 is a safety control flowchart of the implementation device.

3 is a heat exchanger body of a water heater, to which an inlet pipe 2 and an outlet pipe 3 are respectively connected. The water inlet pipe 2 is provided with an inlet water amount detection sensor 4 for detecting the amount of inlet water and an inlet water temperature detection sensor 5 for detecting the inlet water temperature. Further, the hot water outlet pipe 2 is provided with a hot water outlet temperature detection sensor 6 for detecting the outlet hot water temperature.

The heat exchanger body 1 is heated by, for example, burning oil.
It can be carried out. Oil from the oil pipe 11 passes through the electromagnetic on-off valve 12 and enters the oil supply pressure stabilizer 13, and is sent to the nozzle-type combustion burner 15 by the injection pump 14.
Subjected to combustion. A portion of the oil sent to the combustion burner 15 can be returned to the oil supply pressure stabilizer 13 via a return circuit 16. A proportional control valve 17 is provided in the return circuit 16, and the proportional control valve 17 can adjust the oil flow flowing through the return circuit 16, and as a result, the amount of combustion in the combustion burner 15 can be adjusted. .

21 is a blower. The air volume of the blower 21 and the opening degree of the proportional control valve 17 are controlled by commands from the controller 31.

The controller 31 is composed of, for example, a microcomputer and its peripheral equipment, and includes software for operating the water heater. Then, the controller 31 inputs information from the water input amount detection sensor 4, input water temperature detection sensor 5, hot water output temperature detection sensor 6, hot water temperature setting device 41, etc., and sends corresponding commands to the electromagnetic on-off valve 12 and the proportional control valve 17. , the blower 21, the notification means 51, etc.

The temperature setting device 41 can be provided as a part of a remote control panel for using a water heater, for example.

The notification means 51 can be configured as, for example, a notification lamp or a notification buzzer. .

The operation of the water heater will be explained with reference to FIG. 2, focusing on its safe operation.

Now, when the hot water supply setting temperature is set by the temperature setting device 41 and hot water supply is started, the water input amount detected by the water input amount detection sensor 4, the input water temperature detected by the water input temperature detection sensor 5, and the The required amount of combustion heat per unit time is calculated in the controller 31 from the hot water supply setting temperature, and based on this, the controller 31 adjusts the proportional control valve 17 to the required opening degree and the blower 21 to the required air volume. 31, combustion is started. This is feedforward control at the start of hot water supply.

After combustion is started, the actual hot water temperature inputted from the hot water temperature detection sensor 5 is constantly compared with the hot water supply set temperature, and the proportional control valve 17 and the blower 21 are controlled to eliminate the difference. . This is feedback control.
This is done while hot water supply continues.

In the controller 31, the difference between the actual hot water temperature and the hot water supply setting temperature is constantly calculated for feed bank control. If the time exceeds a certain time, it is detected as an abnormality.

When an abnormality is detected, the electromagnetic on-off valve 12 is closed by the controller 31 and the reporting means 51 is activated.

Appropriate values are determined experimentally as to how many times the outlet temperature exceeds the hot water supply setting temperature to start counting and for how long it lasts depending on the hot water supply setting temperature, the scale of the heat exchange can body 1 and the fuel supply system. It turns out.

<Effects> The present invention has the above-described configuration, and an abnormality is determined when the actual hot water outlet temperature remains higher than the hot water supply set temperature for a certain period of time due to the difference between the hot water supply set temperature and the actual hot water outlet temperature. This structure eliminates the need for special parts such as pressure sensors to detect abnormalities, and the safety mechanism can be configured using the equipment used for proportional control as is, resulting in significant cost reductions and waste reduction. This provides the effect of reliably preventing abnormalities in the device due to clogging, etc.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an implementation device of the present invention, and FIG. 2 is a safety control flowchart of the implementation device. 1: Heat exchanger body 2: Water inlet pipe 3: Outlet pipe 4: Incoming water amount detection sensor 5: Incoming water temperature detection sensor 6: Output temperature detection sensor 11 Nioil pipe 12: Electromagnetic shut-off valve 15: Combustion burner 16: Return circuit 17: proportional control valve
21: Blower 31: Controller 41: Temperature setting device 51: Notification means

Claims (1)

[Claims] It is equipped with a heat exchange can body, a combustion burner for heating the heat exchange can body, and a return circuit for returning a part of the fuel sent to the combustion burner without using it. A safety device for a water heater that automatically eliminates the difference between the hot water temperature and the hot water outlet temperature by adjusting the combustion amount by operating a proportional control valve provided in the return circuit, A safety device for a water heater, which detects this as an abnormality if the temperature remains higher than a certain level for a certain period of time.