JPH035488B2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a gas instantaneous water heater.

(Background of the Invention) Conventionally, there are various structures for gas instantaneous water heaters, but all of them are provided with one burner for one heat exchanger.

As the burner, a so-called gas proportional type burner that controls the amount of heat by changing the amount of gas is often used.

However, the minimum size of the gas proportional type burner is limited to 0/4 to 1/5 of the maximum size due to the structure of the burner.

Therefore, the inventor of the present invention developed a burner that controls the amount of heat by changing the amount of gas, and a burner that controls the amount of heat by changing the amount of gas, and a burner that controls the amount of heat by repeating combustion and extinguishing and changing the ratio of combustion time and extinguishing time. We have invented a gas instantaneous water heater that can reduce the minimum size to nearly 0 and increase the maximum size by providing both a burner that controls this.

Such a gas instantaneous water heater burns two burners individually or simultaneously depending on the amount of heat required, so the problem is how to decide which burner to burn.
If we decide which burner to burn based on the set temperature, hot water outlet temperature, and the required amount of heat calculated by the proportional gain, there will be too much feedback, such as when the water temperature does not rise at the beginning of hot water supply, and the water temperature will rise after a few seconds. If this happens, the burners that are supposed to burn will not ignite, and the burners that should not be burning will burn, so after a few seconds, the burners that were ignited will go out, and the burners that were off will be ignited.
The burner ignites and extinguishes.

(Problems to be Solved by the Invention) The problem to be solved by the present invention is to ensure that the burner that should be used is burned reliably and to prevent the burner from turning on or going out.

(Means for Solving the Problem) The technical means taken by the present invention to solve the above problem is to provide one heat exchanger with a first burner that controls the amount of heat by changing the amount of gas, and a combustion It is equipped with both a second burner that controls the amount of heat by repeating extinguishing and extinguishing and changing the ratio of combustion time and extinguishing time, and burns both burners selectively or simultaneously. It determines which burner is to be burned based on the feed forward heat amount calculated from Based on the final required amount of heat added, it is determined what capacity the burner will burn within the capacity range determined above.

(Function) Since the burner to be burned is determined by feed-back control, even if the water temperature does not rise at the beginning of hot water supply, the burner that should naturally burn will be ignited from the beginning after a few seconds. Even if the amount of feedback is large, the amount of feedback does not exceed the combustion capacity range of the initially selected burner, so there is no possibility of switching to another burner immediately.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

In the figure, reference numeral 4 denotes a water heater, which is equipped with two burners, a first burner 2 and a second burner 3, for one heat exchanger 1, and gas supplied via a gas pipe 5 is supplied to the first burner 2 and the second burner 3. /or second burner 3
The water that is burned and flows through the water supply pipe 6 is transferred to the heat exchanger 1.
It is designed to be heated by

The gas pipe 5 branches at a midpoint into a first gas pipe 5a that communicates with the first burner 2 and a second gas pipe 5b that communicates with the second burner 3, and a former solenoid valve 7 is installed upstream from this branch part. We are prepared.

Further, the first gas pipe 5a has a first
A solenoid valve 8, a governor 9, and a proportional valve 10 are provided in this order, and a second solenoid valve 11 and a governor 12 are respectively provided in the second gas pipe 5b with the former 11 located on the upstream side.

Therefore, when the first solenoid valve 8 is opened, the first burner 2 is supplied with an amount of gas corresponding to the opening degree of the proportional valve 10, and the amount of gas supplied is changed by changing the opening degree of the proportional valve 10. The amount of heat can be changed by changing the amount of heat.

In addition, since a constant amount of gas is always supplied to the second burner 3 by opening the second solenoid valve 11, by repeating the opening and closing of the second solenoid valve 11, intermittent combustion is performed and the time during which the flame is on is reduced. The amount of heat can be changed by changing the amount of time the fire is extinguished.

In the case of this embodiment, the first burner 2 has five burner units 5' and is configured such that the minimum number is 4 and the maximum number is 16, and the second burner 3
is equipped with two single burners 3' and the minimum size is 1.2
The maximum number of water heaters is 6, and the water heater 4 as a whole has a capacity ranging from 1.2 to 22. The second burner 3 burns in the range from No. 1.2 to No. 5.4 (referred to as A zone), and the range from No. 5.4 to No. 16 (referred to as B zone).
In this case, the first burner 2 burns, and in the range from No. 16 to No. 22 (referred to as C zone), the first burner 2 and the second
Both burners 3 are configured to burn.

On the other hand, the water supply pipe 6 is provided with a water flow rate sensor 13 and an incoming water temperature sensor 14 on the upstream side of the heat exchanger 1, and an outlet water temperature sensor 15 is provided on the downstream side of the heat exchanger 1. It is provided close to the exchanger 1 outlet.

Above, water flow sensor 13, water flow sensor 1
4. The hot water temperature sensor 15, the first solenoid valve 8, the proportional valve 10, and the second solenoid valve 11 described above are electrically connected to the control board 16, and the water amount sensor 13 measures the amount of water flowing through the water supply pipe 6. The incoming water temperature sensor 14 detects the temperature of water entering the heat exchanger 1 and produces a signal b, and the outlet water temperature sensor 15 detects the temperature of outlet water from the heat exchanger 1 and produces a signal c. The signals are sent to the control board 16, respectively.

The control board 16 is provided in the machine stand of the water heater 4 or in the control box 17, and includes a required heat amount calculation means 16a and a burner selection means 16, which will be described later.
b, ignition and extinguishing time calculation means 16c, second electromagnetic valve output generation means 16d, proportional valve opening degree calculation means 16
e, a first electromagnetic valve output generating means 16f, a proportional valve driving means 16g, and the like.

The required heat amount calculation means 16a first includes the water amount sensor 13, the incoming water temperature sensor 14, and the outgoing water temperature sensor 1.
The detection signals a, b, and c from 5 are input, and the water amount detected by the water amount sensor 13 and the inlet water temperature sensor 14 are input.
The incoming water temperature detected by the control box 1
The amount of heat of the feed forward is calculated based on the set hot water temperature set in the temperature setting section 18 of No. 7 and the thermal efficiency of the heat exchanger 1, and a signal is generated to the burner selection means 16b.

The burner selection means 16b determines which zone the feedforward heat amount calculated by the required heat amount calculation means 16a falls into, that is, which burner is to be burned. If the range corresponds to
When the range corresponds to up to No. 16, the proportional valve opening calculation means 16e is used, and when the range exceeds No. 16 and corresponds to No. 22, the ignition/extinguishing time calculation means 16 is used.
c and the proportional valve opening calculation means 16e, output signals are generated respectively.

Upon receiving the output of the burner selection means 16b, the ignition and extinguishing time calculating means 16c calculates the ratio of the ignition time and extinguishing time of the second burner 3 according to the feed forward heat amount calculated by the required heat amount calculating means 16a. The output generation means 16 for the second solenoid valve is determined.
send a signal to d.

At this time, the feed-offward heat value exceeded 16.
When it corresponds to the range up to No. 22, the ignition/extinguishing time calculating means 16c determines continuous combustion of the second burner 3.

The second solenoid valve output generating means 16d receives a signal from the ignition and extinguishing time calculating means 16c, and outputs an output d to the second solenoid valve 10 according to the ratio of the ignition time determined by the calculating means 16c to the extinguishing time. Send it to the enemy intermittently or continuously.

The second solenoid valve 11 is a second solenoid valve output generating means 1
In response to the output d of 6d, the valve can be repeatedly opened and closed depending on the interval of the generated output d, or it can be opened continuously.

Therefore, the second burner 3 uses the required heat calculation means 16.
The combustion is performed intermittently or continuously depending on the amount of feed forward heat calculated by a.

When the proportional valve opening calculation means 16e receives the output signal of the burner selection means 16b, it sends a signal to the first electromagnetic valve output generation means 16f, and also calculates the opening of the proportional valve 10 based on the calculated feedforward required heat quantity. The opening degree is calculated and determined, and a signal is sent to the proportional valve driving means 16g accordingly.

When the first electromagnetic valve output generating means 16f receives the signal from the proportional valve opening calculation means 16e, it sends an output E to the first electromagnetic valve 8 to open the first electromagnetic valve 8.

The proportional valve driving means 16g is the proportional valve opening calculation means 1
When receiving the signal from 5e, output F is sent to the proportional valve 10 to drive the proportional valve 10, and the opening of the proportional valve 10 is adjusted to the opening calculated by the proportional valve opening calculation means 16e.

Therefore, the first burner 2 burns with a combustion amount corresponding to the calculated feedforward heat amount.

On the other hand, following the above-mentioned calculation of the feed forward heat amount, the required heat amount calculating means 16a calculates the feedback heat amount based on the hot water temperature detected by the hot water temperature sensor 15, the set hot water temperature and the proportional gain, and calculates the feedback heat amount using the above-described In addition to the feed forward heat amount, the final required heat amount is determined, and this is sent via the burner selection means 16b to the ignition/extinguishing time calculation means 16c selected based on the previous feed forward heat amount.
Or, it is sent to the proportional valve opening calculating means 16e to recalculate the ratio of the combustion time to the extinguishing time or the proportional valve opening based on this final required amount of heat, and the second electromagnetic valve output generating means 16d, Proportional valve drive means 16g
The ratio between the opening time and the closing time of the second electromagnetic valve 11 or the opening degree of the proportional valve 10 is corrected.

Therefore, the number (heat amount) of burners that have already been lit is adjusted based on the above determination, but at this time, the amount of feedback does not extend beyond the initially determined zone to other zones.

Therefore, it is determined at what capacity the combustion will occur within the initially determined zone.

In other words, the calculated feedforward heat amount is
If it corresponds to zone A, the control board 16 sends a signal d to the second solenoid valve 11, the second solenoid valve 11 receives the signal d and repeats opening and closing, and the second burner 3 performs intermittent combustion. The ratio between the opening time and the closing time of the second solenoid valve 11, that is, the ratio between the combustion time and the extinguishing time in intermittent combustion, is determined depending on the calculated feedforward heat amount. In addition, it is corrected.

Further, when the feedforward heat amount corresponds to the B zone, the control board 16 sends a signal e to the first solenoid valve 8 and a signal f to the proportional valve 10, and the first burner 2 is ignited. The combustion capacity at the time of ignition is initially determined by the feed-forward heat amount, but it is finally determined in the B zone by adding the feed-forward heat amount.

Further, when the feedforward heat amount corresponds to the C zone, the control board 16 sends signals e and f to the first solenoid valve 8 and the proportional valve 10, and the first burner 2 is temporarily set according to the feedforward heat amount. The second solenoid valve 1 simultaneously ignites and burns with a combustion capacity of
1 to cause the second burner 3 to continuously burn. Then, the feedback heat amount is added to correct the heat amount of the first burner 2, and the combustion capacity in the c zone is determined.

The solenoid valve 7 of the gas pipe 5 is opened and closed by turning on and off the operation switch 19 in the control box 17.

(Effects) Since the present invention determines the burner to be burned based on the feed-forward heat amount that finally settles as the required heat amount, as a result, the burner that should naturally be burned can be ignited from the beginning.

Moreover, even if the amount of feedback is large, the amount of feedback does not extend beyond the combustion zone of the first selected burner, so the number of capacity for combustion within the above zone is determined and burners in other zones are ignited. There is no such thing. Therefore, even when the water temperature does not rise at the beginning of hot water supply, the burner will not turn on or off.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a gas instantaneous water heater showing an embodiment of the present invention, Fig. 2 is a graph showing the relationship between the maximum and minimum capacities of the burners and zones, and Fig. 3 is a graph showing the relationship between the maximum and minimum capacities of the burners and the zones. Chart showing combustion status,
FIG. 4 is a functional block diagram. 1... Heat exchanger, 2... First burner, 3...
2nd burner.

Claims (1)

[Claims] 1 For one heat exchanger, a first burner that controls the amount of heat by changing the amount of gas, and a second burner that controls the amount of heat by repeating combustion and extinguishing and changing the ratio of combustion time and extinguishing time. Both of these burners are provided, and both burners are burnt selectively or simultaneously, and which burner to burn is determined by the feed-forward heat amount calculated from the set temperature, inlet water temperature, and flow rate. At the same time, within the capacity range obtained by combustion of the burner determined above, based on the final required heat amount obtained by adding the feedback heat amount calculated from the set temperature, outlet temperature, and proportional gain to the above feed forward heat amount. A gas instantaneous water heater characterized by determining the capacity of combustion.