JPH06103119B2 - Water amount control device for an attached water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention divides the water to be heated into at least two heat exchangers, and heats each of the heat exchangers.
The present invention relates to a water amount control device for a side-by-side water heater in which a plurality of water heaters are connected in parallel so that they merge after heating.

[Prior Art] For example, in a combined water heater having two heat exchangers, a solenoid valve for shutting off the inflow of water is provided in a water pipe to one heat exchanger, and when a small amount of water is used, , When the solenoid valve is closed and the supply of water to one heat exchanger is stopped, and only the other heat exchanger is used for heating, and more than the reference amount of water for opening the solenoid valve is used, The solenoid valve is opened and heated by both heat exchangers. In general, in hot water heaters, a solenoid valve for limiting the amount of water flowing into each heat exchanger is provided in the bypass of the water pipe so that high-temperature hot water can be reliably obtained when the set hot water temperature is high. A water amount control valve that is driven or driven by a gad motor is provided in the water pipe to limit the flow rate of water supplied to each heat exchanger, thereby reducing the load on the heating means such as a burner.

[Problems to be Solved by the Invention] However, in the combined water heater, a solenoid valve for limiting the amount of water is provided for each heat exchanger in order to reliably obtain high-temperature hot water, and the set temperature is set at the start of hot water supply. If it is controlled to close when the temperature is high, the inflowing water can pass through only one heat exchanger with a limited water volume, so in some cases the flow rate may not increase to the reference water volume for opening the shutoff solenoid valve. is there. Therefore, if the set hot water temperature is high,
Since the solenoid valve does not open, there is a problem that only one water heater will operate.

An object of the present invention is to provide a side-by-side water heater that can reliably obtain a large amount of hot water even when the set hot water temperature is high.

[Means for Solving the Problem] The present invention is provided in an inflow path at a part of a plurality of inflow paths for respectively guiding water to a plurality of heat exchangers provided in parallel in a water supply path. A shutoff solenoid valve and a water amount detecting means for detecting the amount of water supplied to the water supply passage, and when the water amount detected by the water amount detecting means is a reference water amount or more, the shutoff solenoid valve is opened. In the water amount control device for an annex type water heater, the inflow passages other than the inflow passage provided with the shutoff solenoid valve are provided to limit the inflow water amount, and at the start of inflow of water to the water supply passage. A limiting solenoid valve that is opened and a temperature setting unit that sets the temperature at which hot water is heated by the heat exchanger are provided. When the hot water temperature set by the temperature setting unit is equal to or higher than a predetermined temperature, Is a water flow detected by the water amount detection means After that, for a predetermined time, the limiting solenoid valve is opened, and when the water amount detected by the water amount detecting means is equal to or more than the reference water amount, the shutoff electromagnetic valve is maintained in the open state, If it is less than the amount of water, the technical means is to close the shut-off solenoid valve and to close the limiting solenoid valve after a predetermined time.

[Operation] In the present invention, when water flows into the water supply passage, the limiting solenoid valve is opened, and the inflowing water passes only through the heat exchanger connected to the inflow passage that is not provided with the shutoff solenoid valve. To do. When the amount of water is larger than the reference amount of water, the shutoff solenoid valve is opened, and the water also flows into the inflow passage and the heat exchanger in which the shutoff solenoid valve is provided. At this time, if the set hot water temperature is equal to or higher than the predetermined temperature, the limiting solenoid valve is closed after a predetermined time elapses, and the amount of water passing through each inflow path and each heat exchanger is limited and reduced.

[Effect of the Invention] In the present invention, when the set hot water temperature is equal to or higher than the predetermined temperature, the restricting solenoid valve is closed after a predetermined time has elapsed since the shutoff solenoid valve was opened, and therefore flows into the water supply passage. The amount of water used does not fall below the reference amount by closing the limiting solenoid valve. Therefore, the shutoff solenoid valve is continuously opened, and the supplied water is heated by each heat exchanger, so that the hot water discharge temperature can be raised and a large amount of hot water discharge can be ensured. Obtainable.

EXAMPLES Next, the present invention will be described based on examples.

The side-by-side gas water heater 1 shown in FIG. 2 supplies water supplied from a water supply pipe 2 connected to a water supply source (not shown) to the water pipes 10 and 20.
The heat is supplied to the hot water supply pipe 2a by heating the heat exchangers 11 and 21 respectively, and then the hot water is supplied to the hot water supply pipe 2a. Combustors 30, 40 with capacity are provided, each heat exchanger 11,
Each of the water passing through the inside of 21 is heated. Combustor 30,
40 is controlled by control circuits 50 and 60, respectively. The amount of water passing through the water pipes 10 and 20 is controlled by the relay control circuit 70, and each circuit is controlled according to the operation of the controller 80.

The water supply pipe 2 is provided with a water amount sensor 4 and an incoming water temperature thermistor 5, and the supplied water is guided to the heat exchangers 11 and 21 by the water pipe 10 and the water pipe 20 after the water amount and the water temperature are detected. . One of the branched water pipes 20 is provided with a water solenoid valve 6 which is opened when energized, and the heat exchanger 21 is supplied with water only when the water solenoid valve 6 is energized. The upstream and downstream sides of the water solenoid valve 6 are connected by a bypass pipe 7 having an extremely small diameter, and even when the water solenoid valve 6 is in a closed state, a small amount of water is generated by the heat exchanger.
By passing through the inside of 21, the accumulated water when the combustor 40 is not used is eliminated.

Each water pipe 10, 20 upstream of each heat exchanger 11, 21 has a water flow switch 12, which closes the contact when the amount of passing water exceeds a certain amount.
22 and automatic water quantity control switching devices 13 and 23 are respectively provided. Here, the water flow switch 12 closes the contact with a water amount of 2.9 ± 0.5 l / min or more, and opens the contact when the water amount becomes 2.2 ± 0.5 l / min or less. On the other hand, since the water flow switch 22 is provided with the water solenoid valve 6 that generates passage resistance in the water pipe 20, the amount of working water is set to be less than that of the water flow switch 12, and the water flow switch 22 is set to 2.3 ± 0.4
The contact is closed when the amount of water is l / min or more, and the contact is opened when the amount is 1.4 l / min or less.

The automatic water volume control switching devices 13 and 23 are automatic water volume control valves 14 and 24 that sense the temperature of water and automatically control the amount of water passing through.
And the water quantity switching valves 16 and 26 provided in the bypass pipes 15 and 25 that connect the upstream and downstream of the automatic water quantity control valves 14 and 24, respectively, to the respective heat exchangers 11 and 21. Adjust the inflow of water. The automatic water amount control valves 14 and 24 decrease the opening when the temperature of the supplied water is low, and increase the opening as the temperature rises. Therefore, the automatic water amount control switching devices 13 and 23 correspond to changes in the water temperature of 5 to 25 ° C. in the range of 6 to 10 l /, for example, when the water amount switching valves 16 and 26 are closed.
Adjust so as to supply water for a minute, and when each of the water quantity switching valves 16 and 26 is in the open state, supply 9 to 13 liters / minute of water corresponding to the change in water temperature of 5 ° C to 25 ° C. Adjust to.

The water pipes 10 and 20 downstream of the heat exchangers 11 and 21 have tap water temperature thermistors 17 and 27 for detecting the temperature of heated hot water.
Water pipes 10 and 20 are provided downstream of the hot water supply pipe 2a.
Will be joined by.

Within each combustor 30, 40 are multiple ribbon burners 31, 41.
The burners 31, 41 are provided with nozzle pipes 32, 42 each having an ejection port formed corresponding to each burner 31, 41. The nozzle pipes 32 and 42 are fuel pipes 3 branched from a gas pipe 8 for supplying fuel gas from a fuel supply source (not shown).
Fuel gas is guided by 3, 43. Each fuel pipe 33, 43 is provided with a source solenoid valve 34, 44, a main solenoid valve 35, 45, and a proportional valve 36, 46, respectively. Further, the combustors 30 and 40 are provided with blowers 37 and 47 for supplying combustion air to the burners 31 and 41, respectively.

Further, in the vicinity of each burner 31, 41 in the combustor 30, 40,
Sparkers 38 and 48 for ignition and flame rods 39 and 49 for detecting flames are provided, respectively.

The control circuit 50 and the control circuit 60 operate independently of each other to independently control the combustor 30 and the combustor 40, respectively.
As shown in FIG. 3, sequence control units 51 and 61, respectively.
And combustion control units 52 and 62.

In the control circuit 50, when the water flow is detected by the water flow switch 12, the sequence control unit 51 performs ignition control in a predetermined sequence, operates the blower 37 to supply combustion air to the burner 31, and the blower 37. When the number of revolutions of the solenoid valve reaches a predetermined number of revolutions, the sparkler 38 is activated and
And the main solenoid valve 35 is opened to supply the fuel gas to the burner 31.

Also, when flame is detected by the frame rod 39, the spark
The operation of 38 is stopped, and when flame is no longer detected by the frame rod 39, misfire is detected and each solenoid valve provided in the fuel pipe 33 is closed for safety.

The combustion control unit 52 controls the blower 37 and the proportional valve 36 based on the temperature set by the controller 80 transmitted through the relay control circuit 70 and the hot water temperature detected by the hot water temperature thermistor 17, respectively, and the combustor. Adjust the combustion amount of 30.

The control circuit 60 controls the combustor 40 independently of the control circuit 50, and its control is exactly the same as that of the control circuit 50, and therefore its explanation is omitted.

The relay control circuit 70 controls the water solenoid valve 6 and the water quantity switching valve 16,
Control 26.

The water solenoid valve 6 is controlled so that when a large amount of hot water is required, the heat exchanger 11 and the heat exchanger 21 and the combustor 30 and the combustor 40 are used together.
The water solenoid valve 6 is opened in accordance with the above. Here, based on the incoming water temperature T _IN detected by the incoming water temperature thermistor 5 and the set temperature T _SET set by the controller 80,
The reference water amount L ₀ is determined as follows, and when the detected water amount L is equal to or greater than the reference water amount L ₀ , the water solenoid valve 6 is opened.

When the set temperature T _SET is 55 ° C or higher, the reference water amount L ₀ is 7.0 ± 1.0 l / min regardless of the water temperature T _IN .

When the set temperature T _SET is less than 55 ° C., as shown in FIG. 4, the reference water amount L ₀ for switching the water solenoid valve 6 is changed according to the incoming water temperature T _IN .

When the input water temperature T _IN is less than 15 ℃, the reference water volume L ₀ is uniformly set to 7.0 ±
1.0l / min. When the input water temperature T _IN is 15 ° C or higher and lower than 25 ° C, the reference water amount L ₀ is changed based on the input water temperature T _IN in a relation approximately represented by L ₀ = 0.16 × T _IN +4.6. It

When the input water temperature T _IN is 25 ° C or higher, the standard water volume L ₀ is uniformly set to 8.6 ± 1.0 l / min.

In addition, once the water solenoid valve 6 is opened, the detected water amount L
However, it will be closed when each becomes 1.4 ± 0.8 l / min less than each of the reference water amounts L ₀ .

In the control of the water amount switching valves 16 and 26, when the water flows in and is detected by the water amount sensor 4, the relay control circuit 70 opens the water amount switching valve 16 and causes the water amount equal to or greater than the reference water amount L ₀ determined as described above. Ensure a water passage to allow water to enter.

Further, when the reference water amount L ₀ or more and the set temperature T _SET by the controller 80 is high and 55 ° C. or more, in order to reliably raise the temperature of the water, the water amount switching valves 16 and 26 are closed, The amount of water passing through each heat exchanger 11, 21 is reduced. At this time,
If the water amount switching valve 16 is closed before the water solenoid valve 6 is opened, the inflowing water will pass through only the water pipe 10 whose passing water amount is limited by the water amount switching valve 16, so that the inflowing water amount is reduced. I can't do much. Therefore, the reference water volume L ₀
Although the above flow rate is required, the inflow water amount does not reach the reference water amount L ₀ .

Therefore, in the relay control circuit 70 of the present embodiment, the water solenoid valve drive circuit 71 and the water amount switching valve drive circuit 71a shown in FIG. 1 are controlled to close the water amount switching valve 16 after the water solenoid valve 6 is opened. is doing.

The water solenoid valve drive circuit 71 and the water amount switching valve drive circuit 71a will be described below with reference to FIG.

The water solenoid valve drive circuit 71 is a transistor that performs a switching operation based on a control signal input from the drive control unit 72.
The water solenoid valve 6 is driven by 73, and the drive control unit 72
Outputs a control signal based on the reference water amount L ₀ determined as described above.

Here, the drive control unit 72 outputs a high-level control signal as the control voltage when the water solenoid valve 6 is opened and a low-level control signal when the water solenoid valve 6 is closed. Control voltage is diode 74, resistors 75, 76
Is input to the base of the transistor 73 through.

The water solenoid valve 6 is connected to the resistor 77 connected to the collector of the transistor 73 and the power source V _P, and is energized to open when the transistor 73 is turned on.

The water amount switching valve drive circuit 71a includes a temperature control voltage output from the temperature control unit 72a and a diode 74 of the water solenoid valve drive circuit 71.
The water amount switching valve 16 is driven by a transistor 73a that performs a switching operation based on a control voltage transmitted via the.

Here, the temperature control voltage from the temperature control unit 72a is a low level when the set temperature T _SET set by the controller 80 is 55 ° C. or higher, and a high level when the set temperature T _SET is less than 55 ° C. It is used when determining the reference water amount L _O of the water solenoid valve 6.

When the temperature control voltage output from the temperature controller 72a is at high level, the capacitor 81 is charged via the resistor 78 and the diode 79. The transistor 73a performs a switching operation according to the voltage input to the base via the resistor 76a.

On the other hand, the control voltage transmitted via the diode 74 of the water solenoid valve drive circuit 71 is inverted by the inverter 82 and applied to the connection point 85 between the resistor 78 and the diode 79 via the resistor 83 and the diode 84.

Water switching valve 16, which is connected to the resistor 77a and the power supply V _P which is connected to the collector of the transistor 73a, in the open state is energized when the transistor 73a is turned on.

Therefore, in the water quantity switching valve drive circuit 71a, a timer for which the time constant Δt is determined by the capacitor 81 and the resistor 76a is formed, and therefore, when the voltage at the connection point 85 is inverted from the high level to the low level, the predetermined time Delayed by Δt,
The water quantity switching valve 16 is closed.

With the above configuration, in the water quantity switching valve drive circuit 71a, when the set temperature T _SET is less than 55 ° C, the temperature control unit 72a outputs a high-level temperature control voltage.
Regardless of the control state of 72, the transistor 73a is turned on and the water quantity switching valve 16 is opened.

When the set temperature T _SET is 55 ° C. or higher, a low level temperature control voltage is output from the temperature control unit 72a, so that it operates according to the control state of the drive control unit 72 input via the diode 74. To do.

Further, the relay control circuit 70 transmits the signal of the set temperature T _SET by the controller 80 to the control circuits 50 and 60.

The combined gas water heater 1 having the above configuration operates as follows, as shown in FIG.

When the user opens a faucet (not shown), water is supplied into the water supply pipe 2. At this time, the water solenoid valve 6 is closed, and the inflowing water flows only into the water pipe 10. If the inflow of water is detected, the amount of water switching valve 16 is opened, the incoming water temperature thermistor 5 and water sensor 4 is detected water quantity L and the incoming water temperature T _IN, respectively, the detected amount of water L entering water temperature T _IN According to the reference water volume L ₀ determined by, each operates as follows.

1) When the set temperature T _SET is less than 55 ° C In this case, the reference water amount L _{0 at} which the water solenoid valve 6 is opened differs depending on the incoming water temperature T _IN , and the detected water amount L is the above reference water amount L. When it is less than ₀ , the water solenoid valve 6 is not opened, and water is supplied only from the water pipe 10 to the heat exchanger 11. Therefore, since only the control circuit 50 operates and only the combustor 30 burns, the inflowing water is heated only by the heat exchanger 11,
It flows out from the hot water supply pipe 2a.

When the detected water amount L is equal to or more than each of the reference water amounts L ₀ , the water solenoid valve 6 and the water amount switching valve 26 are simultaneously opened, and the water flowing into the water supply pipe 2 is divided into the water pipe 10 and the water pipe 20. Supplied and supplied. Therefore, the water flow switch 12 and the water flow switch 22 are both closed, and the control circuits 50 and 60 are both activated, so that the supplied water is heated by the combustor 30 and the combustor 40.

2) When the set temperature T _SET is 55 ° C or higher a) The water amount L detected by the water amount sensor 4 is 7.0 ± 1.0
When it is less than l / min, the water solenoid valve 6 is not opened and the water is a water pipe.
It is supplied from 10 to only the heat exchanger 11. Therefore, only the water flow switch 12 is closed, the control circuit 50 starts combustion control, the combustion of the combustor 30 is started in a predetermined sequence, the inflowing water is heated only by the heat exchanger 11, and flows out from the hot water supply pipe 2a. To do. After that, the combustion amount is adjusted based on signals from the controller 80, each sensor and the like.

b) The water volume L detected by the water volume sensor 4 is 7.0 ± 1.0
When the flow rate is 1 / min or more, the water solenoid valve 6 is opened, and the water flowing into the water supply pipe 2 is divided into the water pipe 10 and the water pipe 20 to be supplied.
After that, when a predetermined time Δt elapses, the water amount switching valve 16 is closed and the amount of water passing through each of the water pipes 10 and 20 is reduced. However, since the water can pass through the water pipes 10 and 20, the reference water amount L ₀ or more is exceeded. The amount of water can be secured.

Therefore, both the water flow switch 12 and the water flow switch 22 are closed, and the control circuit 50 and the control circuit 60 both operate to start combustion control, so that both the combustor 30 and the combustor 40 start combustion and the inflowing water is Are heated by the heat exchanger 11 and the heat exchanger 21, respectively, and merge and flow out from the hot water supply pipe 2a.

As described above, in the present invention, when the set temperature is high,
The water flow control valve that limits the amount of inflow water is closed after a predetermined time has passed since the water solenoid valve was opened. Therefore, when a large amount of hot water supply is required, be sure to operate the two combustors. You can Therefore, the hot water discharge temperature can be raised, and a large hot water discharge amount can be reliably obtained.

In this embodiment, the side-by-side water heater provided with the gas combustor has been described, but other fuel may be used or an electric heater may be used as a heating source.

[Brief description of drawings]

FIG. 1 is a partial circuit diagram showing a water solenoid valve drive circuit and a water quantity switching valve drive circuit in a relay control circuit of a side-by-side gas water heater showing an embodiment of the present invention, and FIG. 2 is a side-view gas of the present embodiment. FIG. 3 is a block diagram showing a schematic configuration of a water heater, FIG. 3 is a block diagram showing a control system in the side-by-side gas water heater of this embodiment, and FIG. 4 is a control characteristic diagram showing a part of water amount control of a relay control circuit. . FIG. 5 is a flow chart showing the operation of this embodiment. In the figure, 4 ... Water quantity sensor (water quantity detecting means), 6 ... Water solenoid valve (shutoff solenoid valve), 16 ... Water quantity switching valve (limit solenoid valve),
70 ... Relay control circuit (water amount control device), 80 ... Controller (temperature setting means).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kenji Endo, 2-26, Fukuzumi-cho, Nakagawa-ku, Nagoya, Aichi Prefecture, Rinnai Co., Ltd. (72) Akio Tanaka, 2-26, Fukuzumi-cho, Nakagawa-ku, Nagoya, Aichi Prefecture Inside Linnai Co., Ltd.

Claims (1)

[Claims] 1. A shutoff solenoid valve provided in a part of an inflow path of a plurality of inflow paths for guiding water to a plurality of heat exchangers provided in parallel in a water supply path, respectively, A water amount control means for detecting the amount of water supplied to the water supply channel, and controlling the water amount of the water heater with the shutoff solenoid valve opened when the water amount detected by the water amount detection means is equal to or greater than a reference water amount. In the device, an inflow passage other than the inflow passage provided with the shutoff electromagnetic valve is provided to limit the amount of inflow water, and the limiting solenoid is opened at the start of inflow of water into the water supply passage. Valve and
And a temperature setting means for setting a hot water outlet temperature to be heated by the heat exchanger, and when the hot water outlet temperature set by the temperature setting means is equal to or higher than a predetermined temperature, the water amount detecting means detects a water flow. For a predetermined time after the opening, the limiting solenoid valve is opened, and when the water amount detected by the water amount detecting means is equal to or more than the reference water amount, the shutoff electromagnetic valve is maintained in the open state and less than the reference water amount. In this case, the shutoff solenoid valve is closed, and after a predetermined time, the limiting solenoid valve is closed.