JPS6176842A - Tap-controlled water heater - Google Patents

Abstract

PURPOSE:To effectively control the fluctuation of the hot water temperature at the time when the hot water discharge is restarted as well as the time lag for the transition to the stabilized hot water supply. CONSTITUTION:By the switching on of a water flow switch 12 which ensues upon the first opening operation of a hot water tap 3A, a heater 14 starts to be electrified, and by the timer control in which a solenoid gas valve 7 is opened after a set preheating time has elapsed, the burner 2 starts its burning operation. After the first hot water discharge, a prepurge for the following hot water discharge is made unnecessary by maintaining the electrification to the red-hot electric heater 14 while the hot water discharge is stopped. This also contributes to keep the hot water temperature in an heat exchanger 4, and to control the fluctuation of the hot water temperature at the time when the hot water discharge is restarted as well as the time lag for the transition to the stabilized hot water supply. Meanwhile, based on the feedback information from a hot water temperature sensor 9, the opening of a proportionate control valve 8 is controlled by a control device 16 so that the hot water temperature as detected may be maintained at a temperature set by a switch 19.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an instantaneous hot water supply system in which a closed combustion chamber equipped with a forced ventilation device is equipped with a gas burner and a heat exchanger for heating water heated by the gas burner. Regarding boilers.

[Prior Art] Conventionally, in the above-mentioned type of instantaneous water heater, the burner was directly ignited by continuously sparking the ignition igniter when the water supply was started. (The grammar cannot be shown.) [Problems to be solved by the invention] However, in the above-mentioned conventional device, after the hot water supply start operation, the forced ventilation device is started and the combustion chamber is heated before the burner is ignited. Because it requires a so-called pre-purge to scavenge air, when hot water is repeatedly supplied, the hot water that remains in the piping from the previous hot water supply and is close to the set hot water temperature is discharged, and then, before re-ignition, The cold water that passed through the heat exchanger during the pre-purge is discharged, and then the discharge of hot water heated by the re-ignited burner at the set hot water temperature is started, which causes the fourth As shown by the broken line in the figure, there is a problem that not only does it cause large fluctuations in the hot water temperature at the time of re-starting hot water supply, but it also causes a large time delay from the artificial hot water supply start operation until stable hot water supply actually starts. The reality is that users feel a great deal of inconvenience because of the time delay that occurs each time they reheat hot water.

The present invention is a rational and simple improvement to the burner ignition structure to effectively suppress fluctuations in hot water temperature and delays in starting stable hot water supply during reheating operations.

[Failure to solve the problem]

The instantaneous water heater according to the present invention has a characteristic configuration in which a red-hot electric heater for igniting a burner is housed in a closed combustion chamber, and a control means is provided to continue energizing the heater when hot water supply is stopped. Its actions and effects are as follows.

[Function] In other words, by continuing to energize the red-hot electric heater for igniting the burner and maintaining the red-hot state of the heater when the hot water supply is stopped, unburned gas can unexpectedly fill the combustion chamber when the hot water supply is stopped. Since the situation where the burner is stored away can be reliably avoided, there is no need for pre-purging prior to re-igniting the burner as in the past, and the burner can be ignited immediately after the re-heating operation. Moreover, the heat retention effect generated by the heat generated by the heater in the hot water supply stop state prevents the hot water remaining in the water heating heat exchanger from being cooled from the previous hot water supply.

[Effects of the Invention] As a result of the above, as shown by the solid line in Fig. 4, it is possible to effectively suppress fluctuations in hot water temperature during reheating and the time delay in starting stable hot water supply, and to create an instant hot water system that is extremely easy for users to use. It was made into a boiler.

Incidentally, in order to suppress fluctuations in hot water temperature when reheating hot water and the time delay in starting stable hot water supply, we are also considering installing a pilot burner in the combustion chamber that continuously burns when hot water supply is stopped, as a burner ignition device. However, in order to continue the combustion operation of the pilot burner in the closed combustion chamber, it is necessary to operate the forced ventilation device continuously even when hot water supply is stopped, or to use forced air supply such as a blast type to the pilot burner. This requires the use of a special burner, which leads to power consumption and increased costs.Furthermore, the pilot burner requires an ignition device such as a spark plug and a fuel control device such as a gas solenoid valve. As a result, there are problems that further increase costs and complicate the structure.

In this respect, according to the present invention, since it is a mere electric heater,
There is no need for any special structure or special means to maintain the glowing operation of the heater in the closed combustion chamber.
Further, ancillary devices such as spark plugs and solenoid valves can be omitted, making the overall structure extremely simple and inexpensive.

〔Example] Next, embodiments will be described based on the drawings.

Figure 1 shows the general structure of an instantaneous water heater, in which a closed combustion chamber (B) is formed by a casing (1) that forms an upper exhaust port body, and a gas burner is connected to the combustion chamber (B). (2) and a fin-tube water heating heat exchanger (4) connected to the hot water supply pipe (3), and a forced ventilation fan (2) for maintaining the combustion operation of the burner (2).
A passage is connected to the discharge of 5).

An electromagnetic gas valve (7) and a proportional control valve (8) for adjusting heating capacity are installed in the gas fuel supply path (6) to the burner (2), and a hot water temperature sensor is installed in the hot water supply pipe (3). (9
), a constant flow valve (b) and a water flow switch □□□ are installed in the water supply pipe 4 for the heat exchanger (4), respectively, and a Combustion chamber (B
) is provided with a wind pressure switch @ that turns on when the blowing wind pressure is above the set value, and a red-hot electric heater A41 for burner ignition and a flame rod (to) for confirming burner combustion are installed in the combustion chamber (B). In addition, a device uQ1 that automatically controls the hot water supply operation based on information from the above-mentioned sensors and switches, and a remote controller αη that gives manual operation commands to the control device (IQ) are provided.

The hot water supply control flow of the control device αQ is configured as shown in (a) to (c) below. (See Figure 2) B) After the operation switch (G) in preparation for hitting the remote controller is turned on, the first operation to open the hot water tap (3 people) (the water flow switch accompanying the operation to start hot water supply) The fan (5) is started based on the ON operation of step 2), and then the set pre-purge time (1-) is started from the time of the ON operation of the wind pressure switch Q3.
, the heater (141) is started to be energized, and the burner (2 ) starts combustion operation.

Incidentally, after confirming that the burner is ignited by the flame rod 4, the power supply to the heater u4 is stopped.

(0) Closing the hot water tap (8A) (stopping hot water supply)
Based on the OFF operation of the water flow switch (b),
Stop the fan (5) and close the electromagnetic gas valve (7) to stop the combustion operation of the burner (2). 141 is resumed, and the υ heater α field is continuously energized for a set time (ta) under timer control in the hot water supply stop state.

e→ Then, within the set time (1C), the hot water tap (3 people) is operated to open again (operation to start hot water supply again).

When the water flow switch □□□ is turned ON, the 77 (5) is started, and based on the subsequent ON operation of the wind pressure switch, the electromagnetic gas valve is activated at the time of the ON operation. Open (7) and restart the combustion operation of burner (2).

Incidentally, if the re-heating operation is unsuccessful within the set time period (叡a+, ) for maintaining the current supply to the heater α, the control described in (a) above is executed for the next hot-water supply start operation.

In addition, the control for the hot water supply stop operation during reheating is as described above (
This is the same as in (b), and as long as the subsequent re-heating water supply start operation is performed within the set time (to), the controls in (c) and (b) are repeated.

In other words, in the hot water supply control described above, after the first hot water supply, by maintaining the power supply to the incandescent electric heater (b) in the hot water supply stop state, there is no need for pre-purging when starting the next hot water supply, and the heat exchanger ( 4) The deep temperature of the hot water fJ inside is controlled, thereby effectively suppressing the delay in the start of stable hot water dispensing.

On the other hand, the hot water temperature control by the control device q→ is based on feedback information from the hot water temperature sensor (9).
The opening of the proportional control valve (8) is controlled so that the detected hot water temperature is maintained at the temperature artificially set by the hot water temperature setting switch 4.

As shown in FIG. 3, the red-hot electric heater a is constructed by supporting a coiled ceramic (SiC) fRt heat generating body (14A) on a block-shaped insulating holder (14B). By adopting an electric heating element (14A), compared to general metal heating elements, we aim to improve the durability of the heater without using it, and also enable direct use of general-purpose 100V, eliminating the need for a transformer for the heater. Furthermore, it is possible to secure a large amount of heat for heat retention with a small heater.

[Another example]

In configuring the hot water supply control flow of the aforementioned control device uQ, the fifth
As shown in the figure, by continuously driving the fan (5) from the time when the operation switch (G) is turned on, pre-purge is performed when the operation switch (G) is turned on, and after the pre-purge is completed, the first Even in the hot water supply stop state before hot water supply, the heater α may be energized,
By adopting this flow, the temperature rise of the hot water at the time of initial hot water supply will be in the state shown by the solid line in Figure 8, which is much larger than that of the conventional direct a-fired type (dotted line in Figure 6). In addition, in adopting the control flow shown in Fig. 5, in order to make the preheating and heat retention effect on the heater (heat exchanger (4) of 141 effective), when the hot water supply is stopped, The amount of air blown by the fan (5) may be lowered than in the hot water supply state.

Various improvements can be made to the specific configuration of the red-hot electric heater (14A), and ceramic materials other than SiC and various metal materials can be used as the electric heat generator (14A).

[Brief explanation of the drawing]

1 to 4 show embodiments of the present invention, in which FIG. 1 is a schematic overall structure diagram, FIG. 2 is a control time chart diagram, and FIG.
The figure is an enlarged perspective view of the heater, and FIG. 4 is a graph showing the hot water temperature state. 5 and 6 show another embodiment of the present invention, FIG. 6 is a control time chart, and FIG. 6 is a graph showing the rising state of the hot water temperature at the time of initial hot water supply. (2)...Gas burner, (4)...Heat exchanger, (5)...Forced ventilation device, α~...
・Red-hot electric heater, (14A)... Electric heat generator, α
Q... Control means, (B)... Combustion chamber. Agent Patent Attorney Shukan Kitamura 5Figure 1! 6 Figure 2 rIn□

Claims (1)

[Claims] [1] Closed combustion chamber (B) equipped with forced ventilation device (5)
The instant water heater is equipped with a gas burner (2) and a heat exchanger (4) for heating water heated by the gas burner, and a red-hot electric heater (14) for igniting the burner is connected to the combustion chamber ( B), and when the hot water supply is stopped, the heater (1
4) An instantaneous water heater provided with a control means (16) for continuing energization. [2] The instant water heater according to claim 1, wherein the electric heat generator (14A) of the heater (14) is made of ceramic.