JPH0733926B2 - Automatic water heater - Google Patents

Description

TECHNICAL FIELD The present invention relates to an automatic water heater used for filling a bath.

[Prior Art] In Japanese Examined Patent Publication No. 14498/1991, the pulse signals of the flow rate sensor are counted to detect that the total amount has reached a set supply water amount, and the water solenoid valve is closed to stop hot water supply. An automatic water heater for extinguishing a burner is disclosed.

Further, in Japanese Utility Model Laid-Open No. 56-12742, the water supply amount is always kept constant, the set water supply amount is divided by the water supply amount per unit time to calculate the water supply time, and water is supplied during this water supply time. An automatic water supply device that automatically stops water supply is disclosed.

[Problems to be Solved by the Invention] However, since the above-described automatic water heater constantly counts the pulse signal from the flow rate sensor, when performing the calculation of the proportional control of the proportional valve during the counting, a plurality of calculations are performed. Could not be done with one inexpensive microcomputer. As described above, the above-described automatic water heater has a problem in that the cost of the apparatus becomes high because it is necessary to use a plurality of microcomputers or one expensive microcomputer when performing a plurality of calculations. It was

Further, the automatic water supply device described later has a problem that the water supply time calculated by the calculation is deviated when the amount of water supply per unit time changes due to a change in water pressure or the like in the water supply pipe.

The present invention can calculate the remaining hot water supply time and the burner combustion amount with one inexpensive microcomputer.
Another object of the present invention is to provide an automatic hot water supply device capable of preventing the remaining hot water supply time from deviating due to a change in water pressure in the water pipe.

[Means for Solving the Problems] An automatic water heater according to the present invention includes a water pipe that allows water flowing from a water inlet to pass through a heat exchanger and be discharged from a water outlet, and an on-off valve that opens and closes the water pipe. A burner that burns fuel to heat water passing through the heat exchanger, a changing unit that changes a combustion amount of the burner, and a pulse number that oscillates according to a flow rate of water flowing through the water pipe. A flow rate sensor, a temperature sensor for detecting an incoming water temperature of water flowing in from the water inlet, or a hot water temperature of hot water discharged from the hot water outlet, and a water filling for setting a set amount of hot water from the hot water outlet. A quantity setting switch, a hot water outlet setting switch for setting a hot water outlet temperature set from the hot water outlet, and an extraction function for extracting the number of pulses per unit time oscillated from the flow rate sensor at predetermined time intervals longer than the unit time. In function When the number of pulses per unit time is extracted, the current extraction flow rate is calculated from the number of pulses per unit time, and the flow rate per predetermined time obtained from the current extraction flow rate and the previous remaining hot water supply time are calculated. The amount of water filling during the elapsed time is calculated by the product of the elapsed time, and the difference between the amount of water filling during the elapsed time and the amount of water filling up to the previous time and the set amount of water filling is calculated. The remaining hot water supply time is calculated by dividing by the current extraction flow rate, and when the number of pulses per unit time is not extracted by the extraction function, the incoming water temperature or the outgoing hot water temperature, the set outgoing hot water temperature and the The open / close valve is controlled according to a calculation function for calculating the combustion amount of the burner from the current extraction flow rate, and the remaining hot water supply time calculated by the calculation function, and the burner calculated by the calculation function is calculated. It was adopted technical means that includes a single microcomputer having a control function for controlling the changing means in accordance with the baked amount.

[Operation] The automatic water heater of the present invention has the following operations by the above technical means.

The number of pulses per unit time corresponding to the flow rate of water flowing in the water pipe detected by the flow rate sensor is extracted by the extraction function of one microcomputer at predetermined time intervals.

Here, if the number of pulses per unit time is extracted by the extraction function after the lapse of a predetermined time, the calculation function of the microcomputer first calculates the number of pulses per unit time from the extraction function. Is calculated, and then the amount of water filling during the elapsed time is calculated by the product of the flow rate per predetermined time obtained from the current extracted flow rate and the elapsed time from the last remaining hot water supply time. And
The remaining hot water supply time is calculated by dividing the difference between the accumulated hot water filling amount and the set hot water filling amount during the elapsed time and the previous hot water filling amount by the current extraction flow rate.

The control function of the microcomputer controls the on-off valve according to the remaining hot water supply time corrected by the calculation of the calculation function.

Further, when the predetermined time has not elapsed and the number of pulses per unit time is not extracted by the extraction function, the input water temperature or the hot water output temperature detected by the temperature sensor is calculated by the calculation function of the microcomputer, The burner combustion amount is calculated from the set hot water temperature set by the hot water hot water temperature setting switch and the current extraction flow rate calculated at the time of calculating the remaining hot water supply time.

The control function of the microcomputer controls the changing means in accordance with the burner combustion amount calculated by the calculation function. As a result, the burner combustion amount is controlled so that the hot water outlet temperature of the hot water flowing out from the hot water outlet of the water pipe can quickly reach the set hot water outlet temperature.

After that, by repeating the above operation until the remaining hot water supply time elapses, the remaining hot water supply time is corrected every predetermined time, and the burner combustion amount is corrected between the corrections of the remaining hot water supply time. . Therefore, when the remaining hot water supply time elapses and the burner is extinguished, and the on-off valve is closed to stop the outflow of hot water from the hot water outlet of the water pipe, the hot water of the set hot water temperature and the set hot water amount must be ensured. Will be obtained.

[Effects of the Invention] The automatic water heater of the present invention has the following effects due to the above-mentioned technical means and action.

A single inexpensive microcomputer can calculate the remaining hot water supply time and the burner combustion amount. Further, since the remaining hot water supply time is corrected every predetermined time, it is possible to reduce the deviation of the remaining hot water supply time due to the change of the water pressure in the water pipe. Furthermore, since the burner combustion amount is corrected between the corrections of the remaining hot water supply time for each predetermined time,
When the remaining hot water supply time has elapsed, the set hot water temperature and the set hot water discharge amount can be reliably obtained.

[Embodiment] An automatic water heater of the present invention will be described based on an embodiment shown in the drawings.

FIG. 1 shows a schematic view of an automatic bath water heater, and FIG. 2 shows a block diagram of a controller for the bath automatic water heater.

This automatic bath water heater 1 comprises a combustor 2, a gas supply pipe 3, a water pipe 4 and a controller 5.

The combustor 2 is provided with a gas burner 22 having a plurality of gas ejection holes and a fan 23 for supplying air to the gas burner 22 inside a combustion case 21. The air introduced into the gas burner 22 by the fan 23 is discharged from the exhaust port 24 as combustion gas after combustion. In addition, in the vicinity of the gas burner 22 in the combustion case 21, a sparker 25 that ignites the gas burner 22 is provided.

The gas supply pipe 3 supplies the fuel gas into the gas burner 22, and a main solenoid valve 31, a main solenoid valve 32 and a governor proportional valve 33 are sequentially provided from the upstream side in the flow direction of the fuel gas. The main solenoid valve 31 and the main solenoid valve 32 open the gas supply pipe 3 when energized by the control device 5 and close the gas supply pipe 3 when the energization is stopped. Governor proportional valve
In 33, the opening degree changes according to the amount of electricity, and the gas burner 22
The combustion amount of the gas burner is changed by adjusting the amount of gas supplied to.

The water pipe 4 discharges the water flowing in from the water inlet 41 from the hot water outlets 42 and 43, and is provided with a water supply pipe 44, a heat exchanger 45, and a hot water supply pipe 46 sequentially from the upstream side in the flow direction of the water. There is.

The heat exchanger 45 exchanges heat between the heat generated by the combustion of the gas burner 22 and the water flowing inside to heat the water flowing inside.

Further, the hot water supply pipe 46 is branched into two, one of which is used as a bath pipe 47 and is connected to a connection pipe (not shown) which is connected to a hot water supply port (not shown) of the bath at the hot water outlet 42. The other is connected as a hot water supply pipe 48 to a connection pipe (not shown) that is connected at the hot water outlet 43 to a hot water supply port (not shown) other than the hot water supply port of the bath. The bath pipe 47 is provided with a two-way valve 49 as an opening / closing valve. The two-way valve 49 opens the pipe 47 for bath when energized by the control device 5, and closes the pipe 47 for bath when energization is stopped.

The control device 5 is one microcomputer for controlling the energization of the relay circuit 55 and the drive circuit 56 according to the signals sent from the flow rate sensor 51, the incoming water temperature sensor 52, the hot water temperature sensor 53, the water flow switch 54 and the bath controller 6. Equipped with 7.

When the water passing through the water supply pipe 44 flows in the forward direction, the flow rate sensor 51 rotates an impeller having a magnet and a magnetic detection element such as an MR element detects the rotation, and the rotation speed (proportional to the flow rate). The signal is converted into a pulse signal and oscillated by the microcomputer 7. The incoming water temperature sensor 52 is a thermistor that detects the incoming water temperature of the water flowing in from the water inlet 41 of the water pipe 4. The hot water temperature sensor 53 is a thermistor that detects the hot water temperature of hot water discharged from the hot water outlets 42 and 43 of the water pipe 4. The water flow switch 54 sends an ON signal to the microcomputer 7 when the flow rate of water in the water pipe 4 exceeds a predetermined flow rate,
When the flow rate of water in the water pipe 4 is less than the predetermined flow rate, an off signal is sent to the microcomputer 7.

The bath controller 6 includes a main switch 61 of the automatic bath water heater 1, a hot water filling amount setting switch 62 for setting a preset hot water amount as a set hot water discharge amount, and a hot water temperature setting for the hot water temperature set from the hot water outlets 42, 43. A setting switch 63 is provided. The set amount of hot water can be set, for example, every 20 from 20 to 320. Set hot water temperature is 38 ℃
It is possible to set from 1 to 48 ℃ every 1 ℃.

The microcomputer 7 includes a detection function 71, an extraction function 72,
Clock function 73, ignition function 74, calculation function 75 and control function 76
Have.

Detection function 71 detects the hot water temperature detected by hot water temperature sensor 53 and inputs an ON signal or an OFF signal from water flow switch 54.

The extraction function 72 detects the number of pulse signals per unit time oscillated from the flow rate sensor 51 every predetermined time (for example, 3 seconds).

The timekeeping function 73 measures the passage of time.

The ignition function 74 is the main switch 61 of the bath controller 6.
When turned on, a control signal is sent to the relay circuit 55 and the two-way valve 49
Energize. Further, the ignition function 74 sends a control signal to the relay circuit 55 and the drive circuit 56 when the detection function 71 inputs an ON signal from the water flow switch 54, and the fan 23 and the spark
25, the main solenoid valve 31 and the main solenoid valve 32 are energized to turn on the gas burner.
Ignite 22. The ignition function 74 stops energizing only the sparkers 25 after the energizing time of the sparkers 25 has elapsed.

The calculation function 75 calculates the number of pulse signals per unit time by the extraction function 72, calculates the remaining hot water supply time at the time of extraction, and extracts the number of pulse signals per unit time by the extraction function 72. When there is no extraction, the target combustion amount of the gas burner 22 is calculated.

The remaining hot water supply time (for example, 20 minutes) is a predetermined time calculated by calculating the current extraction flow rate from the number of pulse signals per unit time (for example, 1 second) and averaging the current extraction flow rate. The amount of water filling during the elapsed time is calculated by the product of the flow rate per unit time (for example, 10 seconds) and the elapsed time measured from the remaining hot water supply time of the previous time, and the amount of water filling during the elapsed time and the amount of water filling up to the previous time are calculated. Is calculated and calculated from the accumulated amount of water filling and the amount of water filling set by the water filling amount setting switch 62 of the bath controller 6 (for example, 200).

In addition, during the predetermined time excluding the unit time (for example, 9 seconds),
It is calculated as the same number of pulses (that is, the same flow rate) as the number of pulse signals per unit time. That is, in the calculation function 75, the calculation of the remaining hot water supply time is performed every predetermined time (at the time of extraction) during the unit time, and the combustion amount of the gas burner 22 is performed during the other time.

Furthermore, the calculation function 75 is used to calculate the remaining hot water supply time for the next time, the remaining hot water supply time of this time (previous time), the amount of water filling until the last time (the amount of water filling during the elapsed time of each time from the first time to this time A storage unit (not shown) that stores the integrated value), the current extraction flow rate, and the like is incorporated.

The control function 76 controls the governor proportional valve 33 according to the combustion amount of the gas burner 22 calculated by the calculation function 75. Further, the control function 76 sends a control signal to the relay circuit 55 and the drive circuit 56 when the hot water supply time calculated by the calculation function 75 has elapsed, and the fan 23, the original solenoid valve 31, the main solenoid valve 32 and the two-way valve. Valve 49
To stop the hot water filling of the bath and extinguish the gas burner 22.

Ignition control of the microcomputer 7 of the present embodiment will be described based on the operation flowchart of FIG.

First, it is determined whether or not the main switch 61 of the bath controller 6 is turned on (step S1). When the main switch 61 is not turned on (No), the ignition control is stopped.

In step S1, when the main switch 61 is turned on (Yes), the relay circuit 55 is set to energize the two-way valve 49.
The control signal is output to (step S2). Next, it is determined whether or not the ON signal is output from the water flow switch 54 (step S3). When the ON signal is not output from the water flow switch 54 (No), the control of step S3 is repeated.

In step S3, when the ON signal is output from the water flow switch 54 (Yes), the relay circuit 55 is configured to energize the fan 23, the sparker 25, the original solenoid valve 31, and the main solenoid valve 32.
And a control signal to the drive circuit 56 (step S
Four).

Subsequently, it is determined whether or not the energization time of the sparker 25 has elapsed (step S5). When the energization time has not elapsed (No), the control of step S5 is repeated.

In step S5, the energization time has elapsed (Yes)
At this time, a control signal is output to the relay circuit 55 so as to stop energizing the sparker 25 (step S6).

The automatic hot water supply control of the microcomputer 7 and the combustion amount control of the gas burner 22 of this embodiment will be described with reference to the operation flowchart of FIG.

The counting of the pulse signal oscillated from the flow rate sensor 51 is started (step S11). It is determined whether or not a unit time has elapsed since the counting of pulse signals was started (step S12). When the unit time has not elapsed (No), step S12 is repeated.

In step S12, the unit time has elapsed (Yes)
At this time, the current extraction flow rate is calculated from the number of pulse signals per unit time (step S13). Then, the elapsed time from the last remaining hot water supply time stored in the storage means of the calculation function 75 is measured (step S14), and the set water filling amount set by the water filling amount setting switch 62 of the bath controller 6 is set. Read in (step S15).

Next, the remaining hot water supply time of this time is calculated by the above-described calculation method (step S16). Subsequently, it is determined whether or not the remaining hot water supply time has elapsed (step S17). When the remaining hot water supply time has elapsed (Yes), a control signal is sent to the relay circuit 55 and the drive circuit 56 to stop energizing the fan 23, the source solenoid valve 31, the main solenoid valve 32 and the two-way valve 49. Output (step S18) and terminate the automatic hot water supply control.

In step S17, when the remaining hot water supply time has not elapsed (No), it is determined whether or not a predetermined time for extracting the number of pulse signals per unit time has elapsed (step S1).
9). When the predetermined time has passed (Yes), step
Performs control below S11.

In step S19, when the predetermined time has not elapsed (No), the hot water temperature sensor 53 detects the hot water temperature (step S20), and the hot water temperature setting switch 63 of the bath controller 6 is detected.
The set hot water temperature set by is read (step S2
1).

A target combustion amount of the gas burner 22 is calculated from the set hot water temperature, the hot water temperature, and the current extraction flow rate calculated when the remaining hot water supply time is calculated (step S22). This gas burner 2
A control signal is output to the drive circuit 56 so as to control the energization amount of the governor proportional valve 33 according to the target combustion amount of 2 (step
S23), the control after step S17 is performed.

Next, the operation of the automatic bath water heater 1 of this embodiment will be described with reference to the drawings.

When the main switch 61 of the bath controller 6 is turned on,
When the two-way valve 49 is energized and the water flow switch 54 outputs an ON signal, the ignition function 74 causes the fan 23, the sparkler 25,
Energize the main solenoid valve 31 and main solenoid valve 32 to turn the gas burner 22
Light up. The ignition function 74 stops energizing only the sparker 25 after a predetermined time has elapsed. When the gas burner 22 ignites, the water flowing in the heat exchanger 45 is
It is heated by exchanging heat with the heat generated by the combustion of. Then, the heated hot water is discharged into the bath trough (not shown) from the hot water supply port of the bath through the bath pipe 47 of the hot water supply pipe 46 and the connecting pipe.

Then, the computing function 75 of the microcomputer 7 computes the current extracted flow rate from the number of pulse signals per unit time oscillated from the flow rate sensor 51 at predetermined time intervals, and the time counting function 73 causes the remaining time of the last time to be calculated. Measure the elapsed time from the hot water supply time. Then, the flow rate per predetermined time is calculated from the current extraction flow rate according to the following equation 1.

Formula 1 ... Flow rate per predetermined time = {currently extracted flow rate × (predetermined time / unit time)} Next, the amount of water filling during the elapsed time is calculated according to the following Expression 2.

Formula 2 ... Filling amount during elapsed time = flow rate per predetermined time × elapsed time from previous remaining hot water supply time Next, the filling amount up to the previous time stored in the storage means of the calculation function 75 is read. The cumulative amount of water filling is calculated according to the following equation 3.

Formula 3 ... Cumulative amount of water filling = amount of water filling over time + amount of water filling up to the previous time (N) Then, according to the following formula 4, from the set amount of water filling and the accumulated amount of water filling, the current time (N + 1) Calculate the remaining hot water supply time.

Formula 4 ... Remaining hot water supply time of this time = (set amount of hot water filling−total amount of hot water filling) / current extracted flow rate Further, the arithmetic function 75 of the microcomputer 7 extracts the number of pulse signals per unit time. When there is no hot water, the hot water temperature sensor 53 detects the hot water temperature, the hot water temperature setting switch 63 of the bath controller 6 reads the set hot water temperature, and the set hot water temperature, hot water temperature, and remaining hot water supply time are calculated. It is calculated based on the current extracted flow rate that was calculated from time to time. Then, the energization amount of the governor proportional valve 33 is controlled according to the target combustion amount to adjust the opening degree of the governor proportional valve 33 to change the amount of gas supplied to the gas burner 22, thereby changing the amount of gas supplied from the hot water supply port of the bath to the bath tub. The outlet temperature of the hot water flowing into the inside quickly becomes the set outlet temperature. As a result, the hot water at the set hot water temperature is stably supplied into the bath tub.

Then, when the remaining hot water supply time has elapsed, the control function 76 of the microcomputer 7 stops the energization of the fan 23, the original solenoid valve 31, the main solenoid valve 32, and the two-way valve 49 to fill the bath. Is stopped and the gas burner 22 is extinguished, thereby ending the automatic hot water supply control of the microcomputer 7.

Therefore, in this embodiment, since the remaining hot water supply time is corrected every predetermined time, even if the flow rate of the water flowing in the water pipe 4 changes due to a change in the water pressure in the water pipe 4, the remaining hot water supply The time lag can be reduced.

When the number of pulse signals per unit time is being extracted by the extraction function 72 as in this embodiment, the remaining hot water supply time is calculated, and the number of pulse signals per unit time is not extracted by the extraction function 72. At this time, by calculating the target combustion amount of the gas burner 22, a single inexpensive microcomputer 7 can perform a plurality of calculations.

Further, since the target combustion amount of the gas burner 22 is corrected between the corrections of the remaining hot water supply time at every predetermined time, when the remaining hot water supply time elapses, the hot water at the set hot water temperature and the set hot water amount is surely set. Can be filled with water in the bath tub.

[Modification] In the present embodiment, the remaining hot water supply time is corrected every fixed predetermined time, but it is set so that the number of corrections of the remaining hot water supply time increases as the fluctuation of the water flow rate increases. The time may be shortened.

In the present embodiment, the target combustion amount of the gas burner was calculated from the hot water temperature, the set hot water temperature, and the current extraction flow rate.
The target combustion amount of the gas burner may be calculated from the set hot water temperature and the current extraction flow rate.

In the present embodiment, the present invention is adopted in an automatic hot water supply device for a bath that automatically supplies a set amount of hot water, but the present invention automatically applies a set amount of water or hot water to a car wash room, a shower room, etc. It may be adopted in an automatic hot water supply device for supplying.

In this embodiment, a gas burner that burns a gaseous fuel is used as the burner, but a burner that burns a liquid fuel may be used as the burner.

In the bath controller, the remaining hot water supply time may be displayed during filling, and the current extraction flow rate (current extraction flow rate), current filling amount (filling amount during elapsed time + previous filling amount) The amount of tension) or the current residual amount may be displayed.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a schematic view showing an automatic bath water heater, FIG. 2 is a block diagram showing an outline of a control device for the bath automatic water heater, FIG. 3 is an operation flowchart of ignition control of a microcomputer, and FIG. It is an operation flowchart of automatic hot water supply control of a microcomputer and combustion amount control of a gas burner. In the figure, 1 ... Automatic bath water heater, 4 ... Water piping, 7 ... Microcomputer, 22 ... Gas burner, 33 ... Governor proportional valve (changing means), 41 ... Water inlet, 42, 43 ... Tap,
45 ... Heat exchanger, 49 ... Two-way valve (open / close valve), 51 ... Flow rate sensor, 53 ... Hot water temperature sensor (temperature sensor), 62 ... Hot water amount setting switch (Hot water amount setting switch), 63 …… Outlet temperature setting switch, 72 …… Extraction function, 75 …… Calculation function,
76 ... Control function

Claims (1)

[Claims] 1. A water pipe for allowing water flowing in from a water inlet to pass through a heat exchanger and to be discharged from a hot water outlet, (b) an opening / closing valve for opening and closing the water pipe, and (c) a fuel A burner that burns and heats the water passing through the heat exchanger; (d) a changing unit that changes the combustion amount of the burner; and (e) a pulse number according to the flow rate of water flowing through the water pipe. (F) a temperature sensor for detecting the incoming water temperature of the water flowing in from the water inlet, or a hot water temperature of hot water discharged from the hot water outlet, and (g) a temperature sensor for detecting the hot water from the hot water outlet. A hot water filling amount setting switch for setting a set hot water filling amount, (h) a hot water outlet temperature setting switch for setting a preset hot water outlet temperature from the hot water outlet, and (i) oscillation from the flow rate sensor at predetermined time intervals longer than a unit time. Extractor for extracting the number of pulses per unit time When the number of pulses per unit time is extracted by the extraction function, the current extraction flow rate is calculated from the number of pulses per unit time, and the flow rate per predetermined time obtained from the present extraction flow rate and the previous remaining The amount of water filling during the elapsed time is calculated by the product of the elapsed time from the hot water supply time, and the amount of water filling during the elapsed time and the amount of water filling up to the previous time are integrated and the set amount of water filling described above. The remaining hot water supply time is calculated by dividing the difference from the amount by the current extraction flow rate, and when the number of pulses per unit time is not extracted by the extraction function, the incoming water temperature or the outgoing hot water temperature, the A calculation function for calculating the combustion amount of the burner from the set hot water temperature and the current extraction flow rate, and controlling the on-off valve according to the remaining hot water supply time calculated by the calculation function and calculating by the calculation function Done And a microcomputer having a control function of controlling the changing means according to the combustion amount of the burner.