JP2570608B2 - Water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply apparatus, and more particularly, to a hot water supply apparatus having a heat exchanger, a burner for heating the heat exchanger and a blower fan, and hot water discharged from the heat exchanger and water from a bypass pipe. The present invention relates to a hot water supply apparatus for supplying hot water having a set hot water supply temperature while mixing and adjusting the temperature of the hot water with a mixing controller.

[0002]

2. Description of the Related Art A hot water supply device having an instantaneous heat exchanger for supplying hot water at a set hot water supply temperature while mixing and adjusting hot water discharged from the heat exchanger and water from a bypass pipe by a mixing controller. Has conventionally been provided. And, as the minimum working water amount for operating the device, the burner minimum working water amount as a condition that the burner is not burnt unless the flow rate flowing to the heat exchanger is more than that, and the working oil amount is smaller than the burner minimum working water amount. In some cases, the flow rate sets the minimum operating water amount for the mixing controller as the minimum water amount required for the operation of the mixing controller. A schematic configuration of such a hot water supply device will be described with reference to FIG. The apparatus includes an instantaneous heat exchanger 10, a water inlet pipe 11 for sending water to the heat exchanger 10, a hot water pipe 12 for hot water heated by the heat exchanger 10, and a hot water pipe 12 from the water inlet pipe 11. A bypass pipe 13 for bypassing the water, a mixing controller 14 for mixing and adjusting the water from the bypass pipe 13 and the hot water from the tapping pipe 12, and a hot water supply connected downstream of the mixing controller 14. And a tube 15. 16 is a hot water supply curan. The instantaneous heat exchanger 10 is heated by a burner 17 such as a petroleum burner, and blown to the burner 17 by a blower fan 18. Further, the heat exchanger 10
Heat exchange flow sensor 21 and inlet temperature sensor 22
The tapping pipe 12 has a tapping temperature sensor 23 and a tapping pipe 15.
Is provided with a hot water supply temperature sensor 24.

[0003] The operation of the conventional hot water supply apparatus will be described with reference to FIG. When the hot water supply curn 16 is opened, the heat exchange flow sensor 21 detects the minimum operating water amount for the mixing controller or more (Yes in S21), and when the heat exchange flow sensor 21 detects the minimum operating water amount for the burner or more (Yes in S22), the blower fan 18 After the ignition rotation is performed (S23), ignition is performed (S24), and combustion of the burner 17 is started. The water from the inlet pipe 11 is a heat exchanger
The hot water from the tapping pipe 12 passes through the tapping pipe 12 and the hot water from the tapping pipe 12 is supplied with water from the bypass pipe 13.
The hot water appropriately adjusted by 14 and adjusted to the set hot water supply temperature flows to the hot water supply pipe 15. During the combustion (S25), when the heat exchange flow sensor 21 detects less than the minimum working water amount for the burner (S26), the combustion of the burner 17 is stopped and the blower fan is stopped.
If the post-purge by 18 is started, and the heat exchange flow sensor 21 continues to be less than the minimum working water amount for the burner for a certain period of time, for example, a post-purge time of 3 minutes (Yes in S27, Yes in S29). Then, the post-purge is completed (S28). On the other hand, if the heat exchange flow sensor 21 detects the burner minimum operating water amount or more again before the fixed post-purge time has elapsed (No in S29), the blower fan 18 shifts to the ignition rotation again (S23). Ignite. In the above, the rotation speed of the ignition rotation (for example, 3000 rpm
), The number of rotations of the post-purge rotation is generally increased (for example, 4650 rpm) to prevent hot water jetting at the time of post-boiling or re-hot water supply after hot water supply is stopped.

[0004]

In the above-mentioned conventional hot water supply apparatus, for example, when the hot water supply flow rate is small and the set hot water supply temperature is low, or when hot water from a solar water heater is introduced, the required amount of combustion heat (the required heat quantity) is required. Number) and the required amount of combustion heat is the minimum capacity of combustion of the burner 10 (for example, No. 3)
Below. When hot water is supplied with the required amount of combustion heat lower than the minimum combustion capacity of the burner in this manner, even if the burner is burned with the minimum amount of combustion heat, the total amount of heat exceeds the required amount of heat. The exchange flow rate (hot water flow rate) will be reduced. As a result, the heat exchange flow rate sensor 21 detects that the amount is less than the minimum working water amount for the burner, the burner combustion is stopped, and the blower fan 18 reaches the post-purge rotation speed. After a while, the temperature of the hot water and the temperature of the hot water supply are reduced more than necessary because the combustion has stopped, and the flow rate flowing to the heat exchanger 10 is increased again by the mixing controller 14, and reaches the minimum operating water amount for the burner. Then, the rotation speed of the blower fan 18 is reduced to the ignition rotation speed, and combustion is started again. In this way, every time the start and stop of combustion are repeated, the number of rotations of the blower fan is repeatedly switched between the high-speed post-purge rotation and the low-speed ignition rotation, so that there is a disadvantage that noise is generated. Was.

Therefore, the present invention solves the above-mentioned drawbacks of the conventional hot water supply apparatus, and in a hot water supply apparatus in which two minimum working water volumes are set, even when the post-purge rotation and the ignition rotation by the blower fan are frequently switched, the present invention is applicable. Accordingly, it is an object of the present invention to provide a hot water supply device capable of preventing generation of noise by a blower fan.

[0006]

In order to achieve the above object, a hot water supply apparatus of the present invention comprises an instantaneous heat exchanger, a burner for heating the heat exchanger, and a blower fan for blowing air to the burner. A water inlet pipe for sending water to the heat exchanger, a hot water pipe for tapping hot water heated by the heat exchanger, a bypass pipe for bypassing water from the water inlet pipe to the hot water pipe, and water from the bypass pipe. A mixing controller for mixing and adjusting the hot water from the tapping pipe, and the burner's minimum operating water amount required for the burner to burn, and a flow rate smaller than the burner's minimum operating water amount, A minimum operating water amount for the mixing controller required for driving the mixing controller is set, and a heat exchange flow sensor for detecting a flow rate to the instantaneous heat exchanger detects a minimum operating water amount for the burner. If you do , The ignition after ignition rotation by the air blowing fan in the hot water supply operation, when the heat exchange flow sensor detects minimum operating under water for burner,
A hot water supply apparatus configured to perform post-purge air blowing by the air blowing fan, wherein when the heat exchange flow rate sensor detects less than a minimum operating water amount for a burner and less than a minimum operating water amount for mixing, a normal post-purge air supply is performed. On the other hand, if the heat exchange flow sensor detects less than the minimum working water flow rate for the burner but more than the minimum working water flow rate for the mixing controller, the post-purge air flow is performed with a lower air flow rate than the normal post-purge air flow. Controller
It is characterized by having provided .

[0007]

According to the above-mentioned feature of the present invention, even when the heat exchange flow rate sensor selects less than the minimum working water amount for the burner, the amount of water for the mixing controller is not immediately changed to the normal high-speed post-purge air supply. Normal high-speed post-purge air is sent only when the working water volume is less than the minimum. If the water volume is less than the minimum working water volume for the mixing regulator, the mixing regulator itself will no longer operate, and the mixing regulator will not increase the flow rate again above the minimum working water volume for the burner. Therefore, since post-purge is normally stopped without reburning, high-speed post-purge air blowing is preferable. By performing high-speed post-purge air blowing, post-boiling due to post-heating near the heat exchanger 10 can be prevented, and ejection of boiling water or the like at the time of re-water supply can be prevented. on the other hand,
If the amount of water detected by the heat exchange flow sensor is less than the minimum working water amount for the burner but is equal to or greater than the minimum working water amount for the mixing controller, the mixing control operation is still being performed by the mixing controller. The flow rate is likely to be increased above the minimum working water volume for the burner, possibly leading to reignition. Therefore, the post-purge air flow after the combustion is stopped is not performed at a high rotation speed, but the post-purge air flow is performed at a lower rotation speed. Even if it occurs frequently, the difference in the number of rotations at the time of switching to the ignition rotation speed is small, so that it is possible to prevent generation of noise at the time of switching.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
FIG. 1 is an overall configuration diagram of the hot water supply apparatus of the present invention, and FIG. 2 is a flowchart for explaining an operation control operation by the controller 30.

The overall configuration shown in FIG. 1 is the same as the configuration already described in the section of the prior art, so that the description will be omitted. However, the controller 30 is newly specified. The controller 30 controls the entire apparatus, and includes a heat exchange flow sensor 21, an incoming water temperature sensor 22, an outgoing water temperature sensor 23, and a hot water supply temperature sensor 2.
4.Input information from other sensors, input the set hot water temperature information etc. by a remote controller not shown, perform necessary calculations, and input necessary commands to the mixing controller 14, burner 17, and blower fan 18. , Send to others.

The operation control operation by the controller 30 will be described with reference to FIG. Now, when the hot water supply curan 16 is opened, the heat exchange flow rate sensor 21 detects the minimum working water amount for the mixing controller or more (Yes in S1) and detects the hot water flow amount for the burner or more (Yes in S2).
After performing the ignition rotation by the blower fan 18 (S3), the controller 30 ignites (S4) and starts burning the burner 17. The water from the water inlet pipe 11 passes through the heat exchanger 10 to the hot water pipe 12, and the water from the bypass pipe 13 is appropriately adjusted by the mixing controller 14 for the hot water from the hot water pipe 12, and set. The hot water adjusted to the hot water supply temperature flows to the hot water supply pipe 15. Then, during the combustion (S5), when the heat exchange flow sensor 21 detects less than the minimum working water amount for the burner (Yes in S6), the controller 30 stops the combustion of the burner 17 and starts the post-purge air blowing by the blowing fan 18.

In starting the post-purge air supply, the coin roller 30 further determines whether or not the flow rate detected by the heat exchange flow rate sensor 21 is less than the minimum working water amount for the mixing controller (S7). If, for example, the blower fan 18 is rotated at a normal post-purge speed, for example, 4650 rpm
After a predetermined period of time, for example, three minutes (YES in S8), the post-purge air supply ends, and the rotation of the air supply fan 18 is stopped (S10). On the other hand, the step S
In 7, when the flow rate detected by the heat exchange flow rate sensor 21 is less than the minimum working water amount for the burner but not less than the minimum working water amount for the mixing controller (No in S7),
Rotation speed lower than normal post-purge rotation speed, for example, 31
After a predetermined time, for example, 3 minutes has elapsed (YES in S9), the post-purge air supply is terminated, and the rotation of the air supply fan 18 is stopped (S10). The post-purge at a rotation speed lower than the normal post-purge rotation speed may be the same as the ignition rotation speed.

Then, steps S8 and S9 are performed.
In the case where the heat exchange flow sensor 21 detects again the burner minimum operating water amount or more before the fixed time (3 minutes) elapses (NO in S11), the controller 30
The rotation number 18 is switched from the post-purge rotation number to the ignition rotation number (S3), and the operation shifts to re-ignition (S4). The transition from the normal post-purge (S8) to the re-ignition (S3, S4) after step S11 is rare. This is because, in this case, since the mixing controller 14 no longer operates, the flow rate through the heat exchanger 10 does not increase again unless the hot water supply curn 16 itself is opened. Therefore, from step S <b> 8, the blowing is stopped without reburning most of the time. In this case, the post-purge rotation speed is a normal rotation consisting of a high rotation speed, so that heat around the heat exchanger 12 can be effectively cooled, preventing post-boiling, and starting re-hot water supply. Of high-temperature water can be prevented.

On the other hand, during post-purging at a low rotation speed (S
The case of shifting from 9) to re-ignition (S3, S4) via step S11 particularly occurs when the set hot water supply temperature is set low. In this case, as a result of the mixing controller 14 reducing the flow rate flowing to the heat exchanger 10 side, the flow rate once becomes less than the minimum working water amount for the burner, and the combustion of the burner 17 is stopped. When the temperature of the hot water drops, the flow rate flowing again to the heat exchanger 10 is reduced by the mixing controller 14.
Therefore, the flow rate does not become less than the minimum working water amount for the mixing controller, but becomes equal to or more than the minimum working water amount for the burner, and proceeds to re-ignition. By repeating such a state, the switching of the air supply between the post-purge rotation and the ignition rotation is repeatedly performed. In the case of the present invention, in order to prevent such a case from occurring, the rotation speed of the post-purge air is set to a low rotation speed, which is close to the ignition rotation speed. Does not occur. Further, since the flow rate equal to or more than the minimum working water amount for the mixing controller continues to flow, even if post-purge at a low rotation speed is completed, post-boiling is unlikely to occur.

[0014]

According to the present invention, there is provided the above construction.
According to the hot water supply device described in the above, during the combustion, when the heat exchange flow sensor detects less than the minimum working water amount for the burner and less than the minimum working water amount for mixing, it performs normal post-purge air blowing, while the heat exchange flow sensor Is less than the minimum working water flow rate for the burner, but is equal to or greater than the minimum working water flow rate for the mixing controller. In a hot water supply system that sets two minimum operating water volumes, an operating water amount and a minimum operating water amount for the mixing controller, even if the post-purge rotation and the ignition rotation by the blower fan frequently switch, the switching causes noise. This can be prevented from occurring.
Moreover, it is possible to prevent the occurrence of post-boiling after the end of the post-purge in a normal case.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a hot water supply device of the present invention.

FIG. 2 is a flowchart illustrating an operation control operation by a controller 30.

FIG. 3 is a flowchart illustrating a conventional operation control operation.

[Explanation of symbols]

 10 Instantaneous heat exchanger 11 Water inlet pipe 12 Hot water pipe 13 Bypass pipe 14 Mixing controller 15 Hot water supply pipe 17 Burner 18 Blower fan 21 Heat exchange flow sensor 22 Water temperature sensor 23 Hot water temperature sensor 24 Hot water temperature sensor 30 Controller

Claims (1)

(57) [Claims] 1. An instantaneous heat exchanger, a burner for heating the heat exchanger, a blower fan for blowing air to the burner, an inlet pipe for sending water to the heat exchanger, and a heat exchanger. A tapping pipe for tapping hot water, a bypass pipe for bypassing water from the inlet pipe to the tapping pipe, and a mixing controller for mixing and adjusting the water from the bypass pipe and the hot water from the tapping pipe. And a minimum operating water amount for the burner required for the burner to burn, and a minimum operating water amount for the mixing controller required to be set to a flow rate smaller than the minimum operating water amount for the burner and to drive the mixing controller. When the heat exchange flow rate sensor that detects the flow rate to the instantaneous heat exchanger detects the minimum working water amount for the burner or more, the ignition is performed after performing the ignition rotation by the blowing fan. , Pay When the heat exchange flow sensor detects less than the minimum working water amount for the burner during the hot water operation, the hot water supply device performs post-purge air blowing by the blower fan. When it is less than the water amount and less than the minimum working water amount for mixing, normal post-purge air supply is performed, while the heat exchange flow sensor detects less than the minimum working water amount for the burner but more than the minimum working water amount for the mixing controller. A hot water supply apparatus characterized in that a controller for performing post-purge air blowing with a lower air flow rate than normal post-purge air blowing is provided .