JP3571774B2 - Gas water heater - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a gas water heater having an automatic temperature control function.
[0002]
[Prior art]
Generally, in gas water heaters, higher load has been pursued mainly due to the demand for downsizing of the equipment. However, in recent years, there has been a strong demand for noise reduction or energy saving from the standpoint of improving the living environment. However, in order to increase the load, it is necessary to reduce the size of the combustion chamber by shortening the flame. However, since this leads to higher noise and lower thermal efficiency, it is not easy to achieve both. Therefore, conventional gas water heaters are designed so that the maximum hot water supply performance is always exhibited as long as the thermal efficiency and the noise value do not exceed a certain allowable value, and the user has no choice.
[0003]
[Problems to be solved by the invention]
FIG. 3A shows an example of control of a conventional gas water heater with an automatic temperature control function, in which a tapping temperature and a tapping amount are set automatically or manually, and a certain input (fuel supply amount) is selected. And the microcomputer control device automatically adjusts the excess air ratio (the number of revolutions of the combustion air supply fan), and controls the combustion so that the thermal efficiency is always constant (about 80%). This thermal efficiency cannot be freely selected by the user. However, this conventional configuration has an advantage that, for example, "automatic hot watering" of the bathtub is performed in the shortest time and the shower can be used at the maximum hot water supply amount, but the user does not need to be so rushed. In addition, there is a problem that fuel cannot be saved by "energy-saving" driving, and low-noise driving cannot be performed even when it is desired to boil a bath at midnight. The present invention focuses on the fact that if the user does not particularly desire “high-speed hot water supply”, the operation can be performed with higher thermal efficiency and lower noise, and a gas mode that allows the user to select the operation mode. It is intended to provide a water heater.
[0004]
[Means for Solving the Problems]
As shown in FIGS. 1 and 2, the gas water heater according to the present invention is a gas water heater provided with a microcomputer-type control device 3 for controlling a fuel control valve 1 and a combustion air supply fan 2. As a program, a high-load combustion mode that controls the air supply amount by the combustion air blower so that the thermal efficiency becomes constant according to the change in fuel supply amount, and combustion so that the thermal efficiency becomes constant according to the change in the fuel supply amount High-load combustion mode that controls the amount of air supplied by the air blower, and lowering the air ratio compared to the high-load combustion mode to achieve higher thermal efficiency than the high-load combustion mode except near the hot water supply capacity limit of the gas water heater. while preparing the energy-saving combustion mode in which, having thereon a selection switch 5 for selecting the two modes in the operation panel 4 of the water heater, by one device In that it can meet the demands of both the load and low noise to energy saving and has a characteristic.
[0005]
[Action]
When the user desires high-load combustion such as "high-speed hot water", the user can select "normal mode" with the selection switch 5 of the operation panel 4, and desire "energy saving operation" or "low noise operation". If so, the user may select the "energy saving mode". At this time, depending on the selected mode, the control device 3 adjusts the excess air ratio so as to maintain a constant thermal efficiency (about 80%) in the “normal mode” as shown in FIG. As shown in FIG. 3B, the excess air ratio is adjusted so as to maintain the efficiency of 85% at low input and 80% at maximum input, for example.
[0006]
【Example】
FIG. 1 shows an embodiment of a gas water heater according to the present invention, wherein a fuel control valve 1 for proportionally controlling fuel supplied to a gas burner 6 and a fan 2 for supplying combustion air are controlled by a microcomputer-type control device 3. The fuel control valve 1 is controlled in accordance with an input determined by the set tapping temperature and tapping amount, and the fan 2 is a relational curve previously determined in accordance with the input change so that the thermal efficiency becomes 80%. Is controlled in accordance with As a combustion control program installed in the microcomputer-type control device 3, in addition to the normal high-load combustion mode in which the excess air ratio is controlled as shown in FIG. An energy-saving combustion mode controlled as shown in (b), that is, an “energy-saving mode” is prepared. As shown in FIG. 2, the operation panel 4 of the water heater is provided with a selection switch 5 for selecting both modes. I have.
[0007]
Therefore, the user can select the “normal mode” to perform the high-power operation, while not having to rush the hot water to the bathtub, or using the shower after the housekeeper has settled down late at night. By selecting the "energy saving mode" and lowering the air ratio, it is possible to select combustion with high efficiency and low noise. In FIG. 3B, the reason why the thermal efficiency is reduced in the high input portion is that it is difficult to maintain the high efficiency near the limit of the hot water supply capacity of the device.
[0008]
【The invention's effect】
According to the present invention, as described above, by providing two types of operation modes of the gas water heater and relying on the user's selection, high-power operation and high-efficiency operation, which could not be achieved by a single device, can be performed. If the user does not particularly desire high-output hot water or high-speed hot water, the user can save fuel by selecting the "energy saving mode" and operate at low noise at midnight. Since there is a choice, there is an advantage that the living environment can be improved.
[Brief description of the drawings]
FIG. 1 is a system diagram of one embodiment of the present invention.
FIG. 2 is a front view of an operation panel used in the embodiment.
FIGS. 3A and 3B are graphs showing operating states of the above.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fuel control valve 2 Fan for supplying combustion air 3 Control device 4 Operation panel 5 Selection switch

Claims (1)

In a gas water heater provided with a microcomputer control device for controlling a fuel control valve and a combustion air blower, a combustion control program in the above control device uses a combustion air blower so that thermal efficiency is constant according to a change in fuel supply amount. Energy saving in which the heat efficiency is higher than in the high load combustion mode except for near the limit of the hot water supply capacity of the gas water heater by lowering the air ratio compared to the high load combustion mode and the high load combustion mode that controls the air supply amount A gas water heater comprising a combustion mode and a selection switch for selecting both modes on an operation panel of the water heater.

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