JPS63302215A - Motion control device for hot water feeder - Google Patents

Abstract

PURPOSE:To prevent rapid lowering of the temperature of feed hot water during reignition, by a method wherein a feed amount and an amount of fed air for combustion available during ignition of a combustion device are determined to a specified control amount, and return from other proportional control amount to the control amount is automatically effected during extinguishment due to the stop of the feed of hot water. CONSTITUTION:When a hot water feed faucet 7 is kept open under a state in which a main switch for hot feed water is turned ON, a fan motor 15 is turned ON, and after prepurge is effected for a specified time, an igniter 12 is turned ON. After lapse of a specified time, a solenoid pump 10 is turned ON for ignition. When combustion is started, the rotation position of a servo motor 17 is regulated by means of a controller 25 so that a hot feed water temperature is adjusted to a set value, and operation for proportional control of fuel and air for combustion is carried out. When the hot water feed faucet 7 is closed so as to stop the feed of hot water, the solenoid pump 10 is turned OFF, and simultaneously return command to an input position B during ignition of a servomotor 17 is outputted from a controller 25. Meanwhile, in the controller 25, a post-purge timer is started, and after lapse of a specified time, the fan motor 15 is also stopped, and the waiting mode is rendered effective.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an operation control device for a water heater that burns liquid fuel and uses the heat to convert low-temperature water into high-temperature water to supply hot water. More specifically, the hot water supply system automatically controls the amount of fuel supplied and the amount of combustion air supplied in proportion to the required combustion amount based on conditions such as the hot water supply setting temperature, the inlet water temperature, or the inlet water temperature and the actual hot water supply temperature. The present invention relates to a device for controlling the operation of a device.

<Conventional technology> The required amount of combustion heat is calculated from the amount of water entering the water heater, the water temperature, the set hot water temperature, the actual hot water temperature, etc., and the amount of fuel supply and combustion air supply are automatically adjusted in proportion to the amount of heat. A water heater configured to be controlled is also described in, for example, Japanese Patent Laid-Open No. 149527/1983.

In all of these conventional water heaters, after performing proportional control of the fuel supply amount and the combustion air supply amount, when hot water supply is stopped, the means for adjusting the supply amount is stopped while maintaining the controlled amount at the time of the stop. It was configured.

<Problems to be Solved by the Invention> However, in the conventional device described above, when the hot water supply is stopped, that is, when the hot water supply is stopped, the adjustment means stops while maintaining the supply amount of fuel and combustion air at the time of the stop. Next, when re-igniting, it is necessary to operate the adjustment means prior to the ignition, thereby readjusting the supply amounts of fuel and combustion air to the optimal amounts for ignition.

However, operating the adjustment means prior to ignition
This requires time, that is, preliminary operation time, and during that time, even if you open the hot water tap and supply water, it will not ignite immediately. Therefore, at the time of re-ignition, there is a drawback that hot water is supplied at a temperature that has suddenly decreased compared to the previously used hot water temperature.

<Objective> Therefore, the present invention solves the drawbacks of the prior art described above, eliminates the occurrence of the preliminary operation time due to the adjustment means at the time of re-ignition, and suppresses or eliminates the occurrence of a drop in the hot water temperature at the time of re-ignition, that is, the occurrence of undershoot. The purpose is to

Means for Solving Problems> The present invention provides hot water by converting low-temperature water into high-temperature water using the heat generated by the combustion of fuel, and also converts the above-mentioned water supply according to changes in the hot water supply setting temperature, increases and decreases in the amount of water input, etc. This is an operation control device for a water heater that automatically proportionally controls and increases or decreases the amount of fuel supplied and the amount of combustion air supplied, which controls the amount of fuel supplied and the amount of combustion air supplied when a combustion burner is ignited. It is characterized in that it is configured to set a constant control amount in advance and to automatically return to the control amount from other proportional control amounts when extinguishing a fire due to stopping hot water supply.

<Function> Since the fuel supply amount and the combustion air supply amount are configured to automatically return to the control amount at the time of ignition, which is set to a certain amount in advance, when hot water supply is stopped,
When hot water is reheated, the above-mentioned return operation prior to ignition is no longer performed. Therefore, the time required for the return operation is also unnecessary, and the time from the opening of the hot water supply ring to the ignition can be shortened accordingly. Therefore, defects such as a sudden temperature drop (undershoot) of hot water supply upon re-ignition can be prevented. Of course, even at the time of initial ignition, the time from opening the cooker to ignition is shortened, and the time until hot water is supplied at the appropriate temperature is shortened.

<Example> Fig. 1 is an overall configuration diagram of a water heater using the device of the present invention, Fig. 2 is a diagram visually showing control positions by a servo motor,
FIG. 3 is a flowchart showing an example of operation control by the apparatus of the present invention.

Fuel from the burner 2 is combusted within the heat exchange can body l, and the generated high temperature exhaust gas heats the heat exchange coil 3 and is then discharged through the muffler 4. From water inlet pipe 5 to heat exchange coil 3
The water that enters is heated there, passes through a hot water tap 6, and is supplied from a hot water tap 7. Fuel oil is supplied to the burner 2 from an oil supply stabilizer 8 through an oil supply pipe 9 by an electromagnetic pump 10. The tip of the oil supply pipe 9 in the burner 2 is configured with a vari-flow nozzle 11, which spouts out oil. 12 is an igniter. A return circuit 13 is provided in front of the nozzle 11 of the oil supply pipe 9, and is configured to return part of the oil supplied to the burner 2. An oil return amount control valve 14 is provided in the middle of the return circuit 13. By adjusting this control valve 14, the amount of oil ejected from the burner 2 is controlled.

Combustion air is supplied to the burner 2 by a fan motor 15, and a damper 16 controls the actual amount of air supplied.

The position control of the damper 16 that adjusts the supply amount of combustion air and the control valve 14 that adjusts the supply amount of fuel oil is simultaneously performed uniaxially by the servo motor 17, that is, the rotational position of the servo motor 17 is changed. As a result, the position of the damper 16 and the position of the control valve 14 are changed, thereby freely proportionally controlling the supply amount of combustion air and the fuel oil supply amount. 18.19 is a gear. Further, 20 is an incoming water amount sensor, 21 is a mixing valve, 22 is an incoming water temperature sensor, and 23 is an outlet water temperature sensor.

The combustion amount by the burner 2 is controlled by inputting a temperature control command from the temperature setting device 24 to the controller 25.
The controller 25 determines the required combustion amount based on the amount of water entering and the temperature of the water entering.
The rotation position command for the servo motor 17 is calculated by the controller 25 in response to the rotation position command for the servo motor 1.
This is done by outputting to 7. Further, actual hot water temperature information is inputted from the hot water temperature sensor 23 to the controller 25, and the position of the servo motor 17 is controlled by feedback.

As for the combustion amount of the burner 2, the maximum combustion amount and the minimum combustion amount are predetermined, and the corresponding oil supply amount and combustion air supply amount are also predetermined as the maximum input A and the minimum human power C, respectively. Further, the amount of oil supplied and the amount of combustion air supplied at the time of ignition of the burner 2 are also predetermined to be constant amounts as the manual power B at the time of ignition. That is, as shown in Figure 2,
The human power B at the time of ignition is determined as the intermediate input between the maximum human power A and the minimum human power C. The ignition force B is determined by predetermining an optimal value for reducing the ignition noise during ignition and minimizing the generation of soot during ignition.

By determining the human power B at the time of ignition in this way, the burner 2
First, combustion is started at the level of human power B at the time of ignition, and then the input is changed between the maximum input A and the minimum human power C so as to reach a predetermined hot water temperature. In this case, conventionally, the input state when hot water supply is stopped is carried over as is, and the input state is returned to manual power B at the time of ignition only by a preliminary operation prior to ignition during the next hot water supply. In the present invention, when the hot water supply is stopped, the controller 25 commands as a post-operation to return the input state to the human power B at the time of ignition. The servo motor 17 is rotated by a command from the controller 25 to the servo motor 17, thereby moving the control valve 14 and the damper 16 to predetermined positions, and adjusting the levels of the fuel oil supply amount and combustion air supply amount to the level at the time of ignition. Return to human power B level.

The operation of the implementation device will be explained along the flowchart of FIG.

Now, when the hot water supply switch 7 is opened with the main switch for hot water supply turned on, the fan motor 15 is turned on, provided that the minimum operating amount of water is detected.
After pre-purging is performed for a certain period of time, the igniter 12 is turned on. After a certain period of time, the electromagnetic pump 10 is turned on and ignited. At this time, the control valve 14 and the damper 16 have been returned to the manual power B position at the time of ignition at the end of the previous hot water supply. When combustion is started, the rotational position of the servo motor 17 is adjusted by the controller 25 so that the set hot water temperature is reached, and a proportional control operation of fuel and combustion air is started. When the hot water supply switch 7 is closed to stop hot water supply, the electromagnetic pump 10 is turned off, and at the same time, a command to return the servo motor 17 to the ignition manual power B position is output from the controller 25. On the other hand, a post-purge timer is started in the controller 25, and after a certain period of time has elapsed, the fan motor 15 is also stopped and the controller 25 enters a standby mode. When the lock 7 is released during the standby mode, the same re-operation as described above is performed. When the post purge timer is counting
7 is opened, the fan motor 15 is not stopped, the igniter 12 is turned on, and after a certain period of time, the electromagnetic pump 10 is turned on again to enter proportional control operation.

As is clear from the above, in the present invention, the return to manual power B at the time of ignition by rotation of the servo motor 17 is performed by a subsequent operation when hot water supply is stopped.

<Effects> The present invention has the above-described configuration, and with regard to the control of fuel supply and combustion air supply, it is possible to automatically return to a predetermined control amount at the time of burner ignition from another control amount when the fire is extinguished due to a hot water supply stop. Since the system is configured to carry out the water supply automatically, the time required for the control amount return operation prior to ignition at the start of water supply is omitted, and the time from the start of water supply to ignition is accordingly shortened.

Therefore, a sudden drop (undershoot) in the hot water temperature during refilling is prevented. Of course, even when hot water is not reheated, the time from the start of water supply to ignition is shortened, so hot water can be quickly supplied at the appropriate temperature.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of a water heater using the device of the present invention, Fig. 2 is a diagram visually showing control positions by the servo motor, and Fig. 3 is a flowchart showing an example of operation control by the device of the present invention. be.

Claims (1)

[Claims] The heat generated by the combustion of fuel converts low-temperature water into high-temperature water to supply hot water, and the amount of fuel supplied and the amount of combustion air supplied are automatically adjusted according to changes in the hot water supply temperature setting, increases or decreases in the amount of water input, etc. This is an operation control device for a water heater that increases or decreases the amount of water by proportional control, the amount of fuel supplied and the amount of combustion air supplied at the time of ignition of a combustion burner being set in advance to a constant control amount, and other than the control amount 1. An operation control device for a water heater, characterized in that the return from the proportional control amount is automatically performed when extinguishing a fire due to stopping water supply.