JPH03137453A - Hot water feeding device - Google Patents

Abstract

PURPOSE:To accurately prevent the occurrence of after-boiling phenomenon by a method wherein, in a control means for preventing the occurrence of after-boiling to open the bypass valve of a heat exchanger in response to the stop of the feed of hot water, the bypass valve is opened after the lapse of a set time starting from a point of time when the feed of hot water is stopped. CONSTITUTION:When a hot water feed faucet 10 is closed, a controller 15 stops combustion of a burner 2 in response of a water quantity sensor 6, and a blower 19 is stopped. From a point of time when the feed of hot water is stopped, an after-boiling preventing control part 17 starts measurement of a hot water feed stop time, and opens a bypass valve 11 when a time amounts to a given value. A set time is a time matching a time between a point of time when the feed of hot water is stopped and a time in which water remaining a heat exchanger 1 is heated to a high temperature at which after-boiling phenomenon occurs. When the hot water feed faucet 10 is opened again before a time comes to a set waiting time, the control part 17 closes the bypass valve 11 at a point of time when a detecting feed hot water temperature is lowered to a threshold temperature higher by a given temperature difference than a set feed hot water temperature. This constitution prevents the occurrence of after-boiling phenomenon.

Description

Detailed Description of the Invention [Industrial Application Field] The first, second, and third inventions provide a heat exchanger for heating water, and when the heat exchanger is in a water flowing state, A heating means for heating the heat exchanger is provided, a bypass path branched from a water supply waterway to the heat exchanger is connected to a hot water outlet path from the heat exchanger, and a bypass valve is provided for opening and closing the bypass path. The present invention relates to a hot water supply apparatus provided with a control means for preventing after-boiling, which opens the bypass valve in response to the stoppage of hot water output.

[Conventional technology]

Conventionally, in the above-mentioned type of water heater, after the hot water supply stops, the residual water in the heat exchanger becomes high temperature due to the residual heat of the heat exchanger, etc.
To prevent the after-boiling phenomenon in which the high-temperature residual water (high-temperature water) is discharged when the next hot water starts being dispensed, the bypass valve is opened in response to the stop of dispensing water in response to a command from the control means for preventing after-boiling. This is prevented by supplying cold water from the bypass path to the high-temperature residual water from the heat exchanger when the next hot water starts to be dispensed. The boiling prevention control means opens the bypass valve immediately after stopping hot water dispensing, continues to keep the bypass valve open while dispensing hot water, and then opens the bypass valve after a set time from the next start of dispensing hot water. The valve was configured to close.

[Problem to be solved by the invention]

However, in conventional configurations, although attempts are made to prevent the after-boiling phenomenon as described above, there are problems with the length of time after stopping hot water dispensing until the next start of hot water dispensing, and the amount of hot water dispensed when hot water starts dispensing. Depending on the size (the opening degree of the tap), hot water may come out at a temperature lower than the desired hot water temperature, contrary to the after-boiling phenomenon.
In some cases, the after-boiling phenomenon is not sufficiently prevented and hot water is discharged, and there is still room for improvement in accurately preventing the after-boiling phenomenon.

The objects of the first, second, and third inventions are to more accurately prevent the afterboiling phenomenon using a rational control configuration.

[Means to solve the problem]

The water heater according to the first aspect of the present invention is characterized in that it is provided with a heat exchanger for heating water, and a heating means that heats the heat exchanger when water is flowing through the heat exchanger, and A bypass path branched from a water supply channel to the exchanger is connected to a hot water outlet path from the heat exchanger, and a bypass valve is provided to open and close the bypass path, and the bypass valve is opened in response to hot water tap stop. In the configuration provided with a control means for prevention, the control means is configured to open the bypass valve after a set time from the point at which the hot water tap stops.

A characteristic configuration of the hot water supply apparatus according to the second aspect of the present invention is such that the control means is configured to close the bypass valve, which was opened in response to the hot water dispensing stop, when the hot water dispensing stopped state continues for a set standby time from the time when the hot water dispensing is stopped. That's the point.

The characteristic configuration of the hot water supply device according to the third aspect of the present invention is such that, after the start of hot water dispensing, the temperature of the hot water discharged from the heat exchanger detected by the detection means is set to a threshold temperature that is higher than the desired hot water temperature by a preset temperature difference. The bypass valve is configured to close when the temperature drops to .

[For production]

The effects of the characteristic structure of the first invention are as follows.

In other words, the bypass valve is closed during the period when the residual water in the heat exchanger has not yet reached a high temperature after the hot water tap has stopped, and if cold water is supplied from the bypass path in this state, the hot water temperature will become lower than the desired hot water temperature. The valve is maintained in the valve state, and when the set time has elapsed after the hot water supply has stopped and the residual water in the heat exchanger reaches a high temperature, causing an after-boiling phenomenon,
The bypass valve is opened for the first time in preparation for preventing the after-boiling phenomenon when the next tap water starts.

The effects of the characteristic configuration of the second invention are as follows.

In other words, if hot water has been stopped for a long time after the hot water has stopped, and the residual water in the heat exchanger, which has reached a high temperature of - degrees, has cooled down due to heat radiation, supplying cold water from the bypass path will actually lower the hot water temperature. The hot water temperature will be lower than the desired temperature.

Therefore, if hot water continues to be stopped for a set standby time after the hot water tap stops, and the residual water in the heat exchanger becomes low in temperature, the bypass valve that was left open in response to the hot water stop is closed. Put it away.

The effects of the characteristic configuration of the third invention are as follows.

In other words, while the amount of residual water in the heat exchanger is constant, if there is a difference in the amount of hot water at the start of hot water tap,
As a matter of course, the duration of the after-boiling phenomenon also varies.

Therefore, if the bypass valve is simply closed after a preset time from the start of hot water dispensing, as in the conventional system, when the amount of hot water dispensing is large, cold water will flow from the bypass path even though the condition where the after-boiling phenomenon has already ended. This may actually lead to a situation where the hot water temperature is lower than the desired hot water temperature, or when the amount of hot water is small, hot water may be discharged due to the after-boiling phenomenon after the bypass valve closes. This may lead to situations such as.

Therefore, after the start of hot water dispensing, the temperature of the hot water discharged from the heat exchanger detected by the detection means drops to a temperature that is higher than the desired discharge temperature by the set temperature difference, and the state in which the after-boiling phenomenon occurs no longer occurs. When this happens, close the bypass valve.

〔Effect of the invention〕

As a result of the above, according to the first invention, when the next hot water tap is started immediately after the hot water tap stops and the residual water in the heat exchanger has not yet reached a high temperature, unnecessary water is removed from the bypass path. Because of the cold water supply, it is possible to prevent the inconvenience of the hot water temperature becoming lower than the desired hot water temperature, contrary to the after-boiling phenomenon, and it is possible to prevent the after-boiling phenomenon more accurately than conventional devices. reached.

According to the second aspect of the present invention, when the next hot water tap is started after a relatively long period of time has passed after the hot water tap has stopped and the residual water in the heat exchanger has already cooled down due to heat radiation, the bypass path It is possible to prevent the inconvenience that the hot water temperature is lower than the desired hot water temperature due to the unnecessary supply of cold water, contrary to the after-boiling phenomenon. It has now been possible to prevent this.

According to the third invention, depending on the amount of hot water dispensed at the start of hot water dispensing (e.g., depending on the opening degree of the tap), water is discharged from the bypass path in a state where the after-boiling phenomenon has already ended. In order to supply the necessary cold water, the hot water temperature may become lower than the desired hot water temperature, or hot water may come out after the bypass valve is closed due to the after-boiling phenomenon, and the after-boiling phenomenon cannot be sufficiently prevented. This makes it possible to reliably prevent the occurrence of a situation in which there is no water, and it has become possible to more accurately prevent the after-boiling phenomenon compared to conventional devices.

〔Example〕

Next, embodiments of the first, second, and third inventions will be described based on the drawings.

FIG. 1 shows the overall configuration of a water heater, in which (1) is a heat exchanger for heating water, and (2) is a burner as a heating means for heating the heat exchanger (1).

For the hot water outlet path (3) from the heat exchanger (1), there is a bypass path (5) branched from the water supply path (4) to the heat exchanger (1).
) is connected.

(6) is a water flow sensor that detects the amount of water supplied to the heat exchanger (1); (7) is a water temperature correction water valve that automatically adjusts the amount of water supplied to the heat exchanger (1) according to the water supply temperature; ) is a heat exchanger (
1) a hot water temperature sensor (corresponding to the detection means in claim 3), (10) a hot water tap, and (11) a bypass valve that opens and closes the bypass path (5). be.

(12) is a gas valve that intermittents the fuel gas supply to burner (2), (13) is an electromagnetic proportional valve type fuel adjustment valve that adjusts the amount of fuel gas supplied to burner (2), and (14) is an ignition valve. It's a plug.

(15) is a controller that executes operation control based on a manual operation command from a remote controller (16), and (17) is a control means for preventing afterboiling that is incorporated in the controller (15). This is the control section.

Further, (I9) is a blower that blows combustion air to the burner (2), and (20) is a wind pressure switch.

When the hot water tap (10) is opened, the water passes through the water flow sensor (6), the water temperature correction water valve (7), and the heat exchanger (1).
The supplied water flows toward the hot water tap (10), and at this time, in response to the water flow sensor (6) detecting the water flow, the controller (15) starts the blower (19) to When the wind pressure switch (20) is turned on during startup, in response to this, the spark plug (14) starts sparking, the gas valve (12) is opened, and the amount of fuel gas supplied to the burner (2) is controlled. The fuel adjustment valve (I3) adjusts the amount of gas to slowly ignite, thereby slowly igniting the burner (2).

Then, the controller (15) calculates the required combustion amount based on the water supply amount (Q) detected by the water amount sensor (6), the desired hot water temperature (Ta) set by the remote control (16), and the stored water supply temperature, The valve opening degree of the fuel adjustment valve (13) and the blower (
Adjust the rotation speed of step 19) to a value corresponding to the required combustion amount.

The stored water supply temperature is based on the water supply amount (Q) detected by the water flow sensor (6) and the hot water temperature sensor (8) during the previous hot water supply operation.
It is calculated from the heat balance based on the detected outlet hot water temperature (T) and the combustion amount.

Thereafter, the controller (15) finely adjusts the fuel adjustment valve (13) according to the deviation between the outlet hot water temperature (T) detected by the outlet hot water temperature sensor (8) and the set desired outlet hot water temperature (Ta).

Next, when the tap (10) is closed, the water flow sensor (6) is closed.
) in response to the water volume non-detection state, the controller (1
In step 5), the gas valve (12) is closed to extinguish the burner (2), and the blower (19) is stopped after a predetermined period of time (for example, one minute) after the burner is extinguished.

Then, from the time when the hot water tap stops (specifically, when the burner extinguishing operation is performed in this example), the after-boiling prevention control unit (17) measures the hot water tap stop time in order to prevent the after-boiling phenomenon when starting the next hot water tap. When the measured time reaches the set time, the bypass valve (11) is opened.

In addition, the above set time is from the point when the hot water supply stops to the heat exchanger (1)
The time set to correspond to the time required for the residual water in the heat exchanger (1) to be heated by the residual heat of the heat exchanger (1) to a high temperature that will cause an after-boiling phenomenon when the next tap water starts (for example, 5 seconds).

In addition, the after-boiling prevention control unit (17) determines that the after-boiling phenomenon will no longer occur when the next hot water tap starts if the above-mentioned measured time reaches the set standby time while the hot water tap continues to be stopped. Then, the previously opened bypass valve (11) is closed.

Note that the above-mentioned set standby time is based on the period when the hot water supply has stopped and the heat exchanger has become hot due to residual heat.
1) The time (for example, 5 minutes) is set to correspond to the time required for the residual water in the container to be cooled by heat radiation to a temperature that does not cause the after-boiling phenomenon.

On the other hand, if the tap (10) is opened again and hot water is restarted before the measured time reaches the set standby time, the after-boiling prevention control section (17) ), the outlet hot water temperature detected by the outlet hot water temperature sensor (8) (T
) is higher than the desired outlet temperature (Ta) than the set temperature difference (ΔT)
(For example, at the point in time (1) when the temperature (Tb) is higher than 10,100 Cde, it is determined that the condition that causes the after-boiling phenomenon has ended, and until then, the bypass passage (5) is used to prevent after-boiling. The bypass valve (11), which had been left open to supply water, is closed.

[Another example]

Next, another example will be listed.

[a] In the above-described embodiment, the first, second, and third
Although the invention is configured to be carried out together, each of the first, second, and third inventions may be carried out independently, or any two of the three may be carried out in combination. good.

[b] In the above-mentioned embodiment, the hot water tap (10) is opened and the hot water tap is closed in response to opening and closing of the hot water tap to start and stop the hot water tap. Configuration changes are possible.

[C] In the above-mentioned embodiment, when the water flow rate sensor (6) becomes in a state where the water flow rate is not detected, it is recognized that the hot water tap (10) is closed, that is, the hot water tap is stopped. In the case where hot water is started and stopped by opening and closing an automatic valve installed in the water supply channel (3) or water supply channel (4), the stop of hot water supply is recognized from the close command to the automatic valve, and based on this recognition, the bypass valve ( The configuration may be such that the operation 11) is executed.

In addition, although reference numerals are written in the claims section for convenience of comparison with the drawings, the first, second, and third inventions are each limited to the structures shown in the attached drawings. It's not a thing.

[Brief explanation of the drawing]

1 and 2 show embodiments of the first, second, and third inventions, FIG. 1 is an overall configuration diagram of a water heater, and FIG. 2 is a graph showing temperature changes in hot water temperature. be. (1)... Heat exchanger, (2)... Heating means, (4)... Water supply channel, (5)...
Bypass path, (8)...detection means, (11).
... Bypass valve, (17) ... Control means.

Claims (1)

[Claims] 1. A heat exchanger (1) for heating water, and this heat exchanger (
A heating means (2) is provided that heats the heat exchanger (1) when water is flowing through the heat exchanger (1).
) Bypass route (5) branched from the water supply channel (4)
is connected to the hot water outlet path (3) from the heat exchanger (1),
The hot water supply apparatus is provided with a bypass valve (11) for opening and closing the bypass passage (5), and a control means (17) for preventing after boiling that opens the bypass valve (11) in response to the stoppage of hot water output. A hot water supply apparatus, wherein the control means (17) is configured to open the bypass valve (11) after a set time from the point at which the hot water supply stops. 2. Heat exchanger for water heating (1), and this heat exchanger (
A heating means (2) is provided that heats the heat exchanger (1) when water is flowing through the heat exchanger (1).
) Bypass route (5) branched from the water supply channel (4)
is connected to the hot water outlet path (3) from the heat exchanger (1),
The hot water supply apparatus is provided with a bypass valve (11) for opening and closing the bypass passage (5), and a control means (17) for preventing after boiling that opens the bypass valve (11) in response to the stoppage of hot water output. and the control means (17) is configured to close the bypass valve (11), which was opened in response to the hot water supply stop, when the hot water supply stop state continues for a set standby time from the time when the hot water supply is stopped. 3. Heat exchanger for water heating (1), and this heat exchanger (
A heating means (2) is provided that heats the heat exchanger (1) when water is flowing through the heat exchanger (1).
) Bypass route (5) branched from the water supply channel (4)
is connected to the hot water outlet path (3) from the heat exchanger (1),
The hot water supply apparatus is provided with a bypass valve (11) for opening and closing the bypass passage (5), and a control means (17) for preventing after boiling that opens the bypass valve (11) in response to the stoppage of hot water output. The control means (17) is activated by the detection means (8) after the start of hot water dispensing.
The hot water supply is configured to close the bypass valve (11) when the temperature of the hot water discharged from the heat exchanger (1) detected by the temperature drops to a threshold temperature that is higher than the desired hot water temperature by a set temperature difference. Device.