JP2554749B2 - Water heater - Google Patents

Description

TECHNICAL FIELD The present invention relates to a hot water supply apparatus capable of instant hot water supply, and more specifically, to a water supply passage to a water heating heat exchanger heated by a burner. A return hot water passage is provided between the water heating heat exchanger and a hot water supply passage extending to the hot water tap, and circulates the hot water in the hot water supply passage through the return hot water passage to return to the hot water supply passage. A circulation pump is provided, an auxiliary heat source for heating the hot water circulated and circulated by the circulation pump, and a temperature sensor for detecting the temperature of the hot water in the circulation path formed by the water supply path, the hot water supply path, and the return hot water path. , The burner, the auxiliary heat source, and a controller for controlling the operation of the circulation pump. The controller detects the temperature detected by the temperature sensor based on the preset temperature for heat retention. Lower In this case, the burner is ignited to heat the circulating water, and when the temperature detected by the temperature sensor is equal to or higher than the set temperature for burning the burner, the burner is extinguished and the auxiliary heat source is used. Relates to a hot water supply device configured to maintain the circulating hot water at the preset temperature for heat retention.

[Conventional technology]

As this type of hot water supply device, for example, JP-A-63-238356
Some are disclosed in Japanese Patent Publication. In this water heater, when it is detected that the circulating hot water reaches the set temperature for heat retention, first, the energization of the electric heater which is the auxiliary heat source is stopped to reach the set temperature for heat retention. When is continuously detected for the set time, the circulation pump is stopped this time. After that, when it is detected that the temperature is lowered by about 3 degrees from the preset temperature for heat retention due to natural cooling, driving of the circulation pump and energization of the electric heater are restarted, and the hot water reaches the preset temperature for heat retention. It is designed to be maintained.

[Problems to be Solved by the Invention]

In the above-described hot water supply device, the circulation pump is not operated from the time when the state in which the circulating hot water becomes equal to or higher than the set temperature for heat retention exceeds the set time to the time when a temperature three degrees lower than the set temperature for heat retention is detected. It has been stopped. When the circulation pump is stopped, the hot water in the circulation path becomes stagnant, but since the temperature drop due to heat radiation varies from place to place, the temperature of the hot water in the circulation path becomes more uneven as natural cooling progresses. For example, there is a characteristic that the temperature decreases slowly due to residual heat near the burner or the auxiliary heat source, and the temperature decreases rapidly at the exposed portion.

Therefore, if the temperature of the hot water is detected by a temperature sensor provided at one location in the circulation path, even if it is detected that the temperature has dropped by about 3 degrees below the preset temperature for heat retention, The average temperature may be higher or lower than that temperature. As a result, the timing at which the circulation pump is driven and the power to the electric heater is restarted is deviated, which makes it difficult to perform accurate temperature control.

To overcome this difficulty, increase the number of temperature sensors so that the average temperature of the hot water in the circulation path can be detected, or the circulation pump is constantly driven to constantly circulate the hot water in the circulation path. There are possible ways to do this. However, the method of increasing the number of temperature sensors has a drawback that the cost is high, the installation work is complicated, and the processing of the detection result is complicated, and the method of constantly driving the circulation pump consumes a lot of energy. There is a problem that the running cost is high because it is consumed, and it is not satisfactory in any case. By the way, it is possible to reduce the water supply capacity of the circulation pump so that the running cost will be low even if the circulation pump is always driven. It is difficult to put into practical use because it cannot be raised to the maximum.

An object of the present invention is to enable accurate temperature control of a circulation path without increasing the number of temperature sensors and keeping running costs low.

[Means for solving the problem]

To achieve the above object, in the water heater of the present invention, the controller increases the water supply capacity of the circulation pump when the temperature detected by the temperature sensor is lower than the set temperature for burning the burner, and the burner. A first characteristic configuration is that when the temperature is equal to or higher than the set temperature for combustion, the water supply capacity of the circulation pump is switched to a small value, and a water amount sensor for monitoring the water supply capacity of the circulation pump is provided. There is.

The controller includes a burner controller that controls the operation of the burner and an immediate hot water supply controller that controls the operations of the circulation pump and the auxiliary heat source. The burner controller is supplied to the water heating heat exchanger. It is configured to extinguish the burner when the amount detected by the water amount sensor that detects the amount of water is smaller than the set amount of water, and to ignite the burner when the amount of water is greater than or equal to the set amount of water, and the controller for immediate hot water supply is The circulation so that the amount of water in the circulation path becomes smaller than the set amount of water when the water supply capacity is switched to a lower level, and the amount of water in the circulation path becomes greater than or equal to the set water amount when the water supply capacity is switched to a large capacity. A second characteristic configuration is that the pump is configured to control the operation thereof.

[Work]

According to the first characteristic configuration, when the detected value of the temperature sensor is lower than the set temperature for burner combustion, the circulation pump is driven with the water supply capacity switched to a large level, and the heat added from the burner circulates. Try to spread quickly throughout the hot water on the street.

Further, when the detected value of the temperature sensor is equal to or higher than the set temperature for burner combustion, the circulation pump is continuously driven in a state where the water supply capacity is switched to a small level, and the heat added from the auxiliary heat source circulates in the circulating hot water. To do so. By circulating the hot water, the temperature of the hot water is made uniform, and the average temperature of the hot water in the circulation path is detected by a small number of temperature sensors such as one.

In this way, the circulation pump is always driven, but by switching the water supply capacity as necessary, it is possible to quickly raise the hot water temperature while suppressing the increase in running cost. Since the water volume sensor monitors the capacity, for example, when the circulation pump is operating as specified due to a failure of the circulation pump or deterioration of performance, but there is no water supply of a predetermined amount, Therefore, the hot water in the circulation path can be stably and reliably maintained at the preset temperature for heat retention.

According to the second characteristic constitution, the following action is added to the first characteristic constitution.

When the temperature detected by the temperature sensor is lower than the set temperature for burner combustion and the circulation pump is driven with a high water supply capacity, the amount detected by the water amount sensor that detects the amount of water in the circulation path becomes equal to or greater than the set amount of water. The burner ignites.

When the temperature detected by the temperature sensor exceeds the set temperature for burner combustion and the circulation pump is driven with a small water supply capacity, the amount detected by the water amount sensor that detects the amount of water in the circulation path will be less than the set amount. Causes the burner to extinguish.

〔The invention's effect〕

In the first characteristic configuration, the average temperature of the hot water in the circulation path can be accurately detected with a small number of temperature sensors such as one.
Based on the detection result, the auxiliary heat source having a small heat capacity can be efficiently controlled, and the hot water in the circulation path can be stably maintained at the set temperature for heat retention. At that time, the circulation pump is always driven, but since the water supply capacity of the circulation pump is switched to a small value, an increase in running cost can be suppressed. In short, at the start of operation, the running cost of the circulation pump is reduced and the number of temperature sensors installed is reduced while maintaining the function of rapidly raising the total hot water in the circulation path. The hot water can be stably maintained at the set temperature for heat retention, and the water supply capacity of the circulation pump, which is essential for obtaining such effects, is monitored by the water volume sensor, so that the hot water temperature can be maintained more reliably. Became possible.

In the second characteristic configuration, the drive of the circulation pump and the ignition and extinction of the burner can be linked without using an electrically or mechanically linked structure, so that the structure is simplified and the cost is reduced. be able to.

In addition, if you are going to modify the mere hot water supply device equipped with a burner, a water heating heat exchanger, and a water amount sensor into an instant hot water supply device by adding a circulation pump, auxiliary heat source, temperature sensor, etc., electrical wiring There is also an advantage that it eliminates the trouble of doing and reduces mechanical restrictions.

Furthermore, this makes it possible to incorporate a circulation pump, an auxiliary heat source, a temperature sensor, etc. in one case and handle it as an instant hot water supply unit. that way,
The instant hot water supply unit can be easily provided in the hot water supply passage and the hot water supply passage of a hot water supply apparatus that is not of the instant hot water supply type.

〔Example〕

What is shown in the figure is a heat source unit (A) that heats water to hot water having a set temperature for burner combustion that is determined based on the set temperature for heat retention, and a heat source device for keeping hot water when hot water supply is stopped. A hot water supply apparatus including an instant hot water supply unit (B). In this hot water supply device, the heat source unit (A) and the instant hot water supply unit (B) are installed separately. Gas is supplied to the hot water supply device through the gas supply passage (R1) and water is supplied through the water supply passage (R2), and the hot water supply device is connected to the hot water supply passage (R3). ) Is to be supplied with hot water. The first and second hot water taps (1) and (2) are connected to the tip end side of the hot water supply passage (R3). The branch passage (R2 ') from the water supply passage (R2) is connected to the first and second hot water taps (1) and (2), and the first and second hot water taps (1) and (2) are It functions as a so-called mixing stopper.

The heat source unit (A) is internally provided with a burner (3) and a water heating heat exchanger (4) heated by the burner (3) (hereinafter abbreviated as a heat exchanger). The gas supplied through the gas supply path (R1) is burner (3)
Sent to. Further, the water supplied through the water supply channel (R2) is sent to the heat exchanger (4) to be heated and the hot water supply channel (R3).
Is supplied to the first hot water tap (1) and the second hot water tap (2).

2 in the gas supply path (R1) in the heat source unit (A)
The two gas solenoid valves (5) and (6) and the gas proportional valve (7) are interposed, and the water supply channel (R2) in the heat source unit (A) has a water amount sensor (S1) for the heat source unit (patented). (Corresponding to the water amount sensor in the claims), and a hot water temperature thermistor (S) is provided in the hot water supply passage (R3) in the heat source unit (A).
2) and water quantity control valve (8) are installed. Further, an afterglow safety device (9) is attached to the heat exchanger (4), and an overheat prevention device (10) is attached to the support portion of the heat exchanger (4). Below the burner (3) A combustion fan (11) is provided.

Furthermore, all of these are connected to the burner controller (12) for control, and this burner controller (12)
A main controller (13) installed at a position distant from the main body of the water heater is connected to the. The main controller (13) has an operation switch (14) and an operation lamp (1
5), combustion lamp (16), 2 hot water temperature control buttons (17)
Is provided. Household AC 100V is used as the power source for the burner controller (12). In the figure, (18) is a spark plug, (19) is a frame rod for detecting whether or not the burner (3) is ignited, (20) is a drain plug,
(21) is an overpressure relief valve.

The heat source device (A) configured as described above, when the operation amount switch (14) is turned on and the water amount sensor (S1) for the heat source device detects that the water amount is equal to or more than the set water amount, The fan (11) is driven, the two gas solenoid valves (5) and (6) are opened, the burner (3) is ignited, and hot water is supplied. The temperature of the supplied hot water is detected by a hot water temperature thermistor (S2), the opening of the gas proportional valve (7) is adjusted based on the detection result, and the hot water temperature adjustment button (17) is set. The temperature is maintained (set temperature for hot water supply). If the temperature of the supplied water is too low or too high and the adjustment by the gas proportional valve (7) is insufficient, the water amount control valve (8) adjusts the water amount.

Here, if the hot water thermistor (S2) fails or the heat exchanger (3) abnormally overheats because the flow rate of water or gas cannot be adjusted properly, the afterglow safety device (9) is activated. The two gas solenoid valves (5), (6) are closed. When the afterglow safety device (9) does not operate and the heat exchanger (4) overheats abnormally, the overheat prevention device (10) operates and the two gas solenoid valves (5) and (6) close. To be In other words, double safety measures are taken.

The instant hot water supply unit (B) is internally provided with an electric heater (22), which is an example of an auxiliary heat source, a tank (23) accommodating the electric heater (22), a circulation pump (24), and the like. . The water supplied to the heat source unit (A) through the water supply channel (R2) is supplied after passing through the instant hot water supply unit (B), and also through the hot water supply channel (R3).
The hot water supplied to the hot water tap (1) and the second hot water tap (2) is also supplied through the instant hot water supply unit (B). The tank (23) is arranged in the hot water supply passage (R3) in the instant hot water supply unit (B).

A return hot water passage (R4) is connected to the tip of the hot water supply passage (R3), and the tip of the return hot water passage (R4) is connected to the circulation pump (2
Water supply channel (R2) in the instant hot water supply unit (B) via 4)
Connected to By the operation of the circulation pump (24), the hot water supplied through the hot water supply passage (R3) is returned to the water supply passage (R2) through the return hot water passage (R4). A circulation path (R5) is formed by the water supply path (R2), the hot water supply path (R3) and the return hot water path (R4).

Water supply channel (R2) in the instant hot water supply unit (B)
The two check valves (25) and (26) that prevent the hot water in the circulation path (R5) from flowing back to the upstream side of the water supply path (R2) and the water supply capacity of the circulation pump (24) are monitored. A water sensor (S3) for circulation is installed. Also, an instant hot water supply unit (B)
Circulating hot water temperature thermistor (S4) in the return hot water passage (R4)
(Corresponding to the temperature sensor in the claims) and a check valve (27) for preventing water in the water supply channel (R2) from flowing into the return water channel (R4) during hot water supply. . Further, the tank (23) is provided with an excessive temperature rise prevention device (28) that stops the energization of the heater (22) when abnormal heating of the heater (22) is detected.

The heater (22), the circulation pump (24), the water amount sensor (S3) for circulation, and the circulating hot water temperature thermistor (S4) are all connected to a controller (29) for general hot water supply. This controller (29) has an operation switch (30),
A 24-hour timer (31) and an earth leakage breaker (32) are connected. Power to the controller (29) is AC 100V for home use.
Are using. In the figure, (33) is a drain plug, and (34) is an overpressure relief valve.

In the instant hot water supply unit (B) configured as described above, when the operation switch (30) is ON, the circulation pump (24) is continuously driven with the water supply capacity being either large or small. , Hot water is constantly circulating in the circulation path (R5). Here, if the difference between the temperature detected by the circulating hot water temperature thermistor (S4) and the preset temperature (for example, 60 degrees at the set temperature for heat retention) is larger than the first deviation (for example, 15 degrees), the circulation pump ( 24) is driven with a high water supply capacity to increase the amount of water, which causes the water amount sensor (S
Detected by 1) above the set water volume. Along with that, the combustion fan (11) is driven as described above, the two gas solenoid valves (5) and (6) are opened, the burner (3) is ignited, and the circulating hot water is uniformly heated. It The difference between the hot water temperature and the set temperature for heat retention is the second deviation (for example, 5
Degree), the circulation pump (24) is driven in a state where the water supply capacity is small, and the amount of water is reduced as compared with the previous time, whereby the water amount sensor (S1) for the heat source device detects that the amount is less than the set amount of water. Along with that, the combustion fan (11) stopped and 2
The two gas solenoid valves (5) and (6) are closed to extinguish the burner (3), and instead, the heater (22) is energized and the circulating hot water is uniformly heated from within the tank (23). It When the hot water temperature further rises and reaches the set temperature for heat retention, the energization of the heater (22) is stopped. When the difference from the preset temperature for heat retention becomes larger than the second deviation due to natural cooling, the heater (22) is energized again.

The immediate hot water supply unit (B) has an operation switch (30).
It starts and stops by turning on and off, but
The time timer (31) can also automatically start and stop when the set time is reached.

[Another embodiment]

The heat source unit (A) and the instant hot water supply unit (B) can be integrally incorporated in one case.

The main controller (13) of the heat source unit (A) and the instant hot water supply unit (B) controller (29) are electrically connected so that the instant hot water supply unit (B) can be operated by the main controller (13). May be.

The auxiliary heat source (22) may be a heater that uses infrared rays or a small heater that burns fossil fuel.

Further, a hot water heater may be connected to the circulation path (R5). In this case, it goes without saying that a valve for intermittently supplying hot water to the hot water heater is incorporated.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by this entry.

[Brief description of drawings]

The drawing is an overall configuration diagram of a hot water supply device according to the present invention. (R2) …… water supply channel, (R3) …… hot water supply channel, (R4) …… return hot water channel, (R5) …… circulation path, (S1) …… water quantity sensor, (S
3) …… Water volume sensor, (S4) …… Temperature sensor, (1),
(2) …… Hot water tap, (3) …… Burner, (4) …… Water heat heat exchanger, (12) …… Burner controller, (22)
…… Auxiliary heat source, (24) …… Circulation pump, (29) …… Controller for instant hot water supply.

Claims (2)

(57) [Claims] 1. A water supply passage (R2) to a heat exchanger (4) for heating water which is heated by a burner (3) and hot water taps (1), (2) from the heat exchanger (4) for heating water. ), A return hot water passage (R4) is provided between the hot water supply passage (R3) and the hot water in the hot water supply passage (R3) through the return hot water passage (R4) to the water supply passage (R2). A circulation pump (24) that circulates and flows back is provided, an auxiliary heat source (22) that heats the hot water that is circulated and fluidized by the circulation pump (24), the water supply passage (R2) and the hot water supply passage (R3). And a temperature sensor (S4) for detecting the temperature of the hot water in the circulation path (R5) formed by the return hot water path (R4),
Controllers (12), (2) that control the operations of the burner (3), the auxiliary heat source (22), and the circulation pump (24).
9) and are provided, and this controller (12), (29)
When the temperature detected by the temperature sensor (S4) is lower than the set temperature for burner combustion which is determined based on the set temperature for heat retention, the hot water circulated and ignited by the burner (3) is heated. When the heating is performed and the temperature detected by the temperature sensor (S4) is equal to or higher than the set temperature for burning the burner, the burner (3) is extinguished and the hot water circulated and flowed by the auxiliary heat source (22). Is a hot water supply device configured to maintain the set temperature for heat retention, wherein the controllers (12) and (29) include the temperature sensor (S4).
When the detected temperature is lower than the set temperature for burner combustion, the water supply capacity of the circulation pump (24) is increased, and when the detected temperature is equal to or higher than the set temperature for burner combustion, the water supply of the circulation pump (24) is performed. A hot water supply apparatus configured to switch the capacity to a small level and provided with a water amount sensor (S3) for monitoring the water supply capacity of the circulation pump (24). 2. The burner controller (12) for controlling the operation of a burner (3), said controllers (12), (29).
And a controller (29) for instantaneous hot water supply that controls the operation of the circulation pump (24) and the auxiliary heat source (22), and the burner controller (12) is the heat exchanger (4) for heating water.
The burner (3) is extinguished when the detected amount of the water amount sensor (S1) that detects the amount of water supplied to the unit is smaller than the set amount of water, and the burner (3) is ignited when the detected amount of water is greater than the set amount of water. The immediate hot water supply controller (29) switches the water supply capacity of the circulation path (R5) to a value smaller than the set water quantity and to a large water supply capacity when the water supply capacity is switched to a small capacity. The hot water supply apparatus according to claim 1, which is configured to control the operation of the circulation pump (24) so that the amount of water in the circulation path (R5) becomes equal to or more than a set amount of water.