JPH07146002A - Hot water supply device - Google Patents

Abstract

PURPOSE:To prevent the generation of noise from a fan when switching an ignition rotation over to a post purge rotation by performing post air purge with a smaller air volume than usually required when the amount of water of a burner is less than its lowest working volume, and which exceeds the lowest working water volume. CONSTITUTION:When a hot water supply faucet 16 is opened, a fan 18 is rotated to ignite with a controller 30 so that a burner 17 is burnt. Therefore, water from a water inlet pipe 11 is heated at a heat exchanger 10 and supplied to a hot water supply pipe 12. The hot water is mixed with water from a bypass pipe 13 at a mixing controller 14 and supplied from a hot water supply pipe 15 as hot water whose temperature is controlled so as to reach a setting hot water supply temperature. When a heat exchanger flow rate sensor 21 detects that the water is less than a minimum amount of working water for burner, a fan 18 supplies air to carry out post air purging. In this case, when it is detected that the water is less than a minimum amount of working water for burner, and the water exceeds a minimum amount of working water for mixing, the post purging operation is carried out with the amount of supply air lower than that of standard air purging.

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 device, and more particularly, to a hot water exchanger, a burner for heating the same, and a blower fan, and hot water discharged through the heat exchanger and water from a bypass pipe. The present invention relates to a hot water supply device for supplying hot water of a preset hot water supply temperature while mixing and adjusting the above with a mixing adjuster.

[0002]

2. Description of the Related Art A water heater equipped with an instantaneous heat exchanger for supplying hot water having a preset hot water temperature while mixing and adjusting hot water discharged from the heat exchanger and water from a bypass pipe with a mixing controller. Has been provided since. As the minimum working water amount for operating the device, the minimum working water amount for the burner, which is the condition that the combustion of the burner is not performed unless the flow rate flowing through the heat exchanger is higher than the minimum working water amount, and the minimum working water amount for the burner Some flow rates set a minimum working water volume for the mixing controller as a minimum amount of water required for the mixing controller to operate. A schematic configuration of such a water heater will be described with reference to FIG. The apparatus comprises an instantaneous heat exchanger 10, a water inlet pipe 11 for sending water to the heat exchanger 10, a hot water outlet pipe 12 for hot water heated by the heat exchanger 10, and a hot water outlet pipe 12 from the water inlet pipe 11. A bypass pipe 13 for bypassing water to the water, a mixing controller 14 for mixing and adjusting water from the bypass pipe 13 and hot water from the hot water outlet pipe 12, and hot water supply connected to the downstream of the mixing controller 14. With tube 15. 16 is a hot water supply. The instantaneous heat exchanger 10 is heated by a burner 17 such as an oil burner, and the blower fan 18 blows air to the burner 17. In addition, the heat exchanger 10 is installed at a position higher than the branch point of the bypass pipe 13.
Heat exchange flow rate sensor 21 and water temperature sensor 22
A hot water outlet temperature sensor 23 and a hot water supply pipe 15 are provided in the hot water outlet pipe 12.
A hot water supply temperature sensor 24 is provided in the.

The operation of the conventional water heater will be described with reference to FIG. When the hot water supply curran 16 is opened, the heat exchange flow rate sensor 21 detects the minimum working water amount for the mixing controller or more (Yes in S21) and the minimum working water amount for the burner (Yes in S22), the blower fan 18 After the ignition rotation is performed (S23), it is ignited (S24), and the burner 17 starts burning. Water from the water pipe 11 is a heat exchanger
The hot water from the hot water coming out of the hot water outlet pipe 12 is mixed with the water coming out of the bypass pipe 13 through the hot water outlet pipe 12
Hot water appropriately adjusted by 14 and adjusted to the set hot water supply temperature flows into the hot water supply pipe 15. Then, during combustion (S25), when the heat exchange flow rate 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 post-purge time of a certain time, for example, 3 minutes, elapses and the heat exchange flow rate sensor 21 continues to be less than the minimum working water amount for burner (Yes in S27, Yes in S29). The post-purge is completed (S28). On the other hand, when the heat exchange flow rate sensor 21 detects again the burner minimum working water amount or more before the fixed post-purge time has elapsed (NO in S29), the blower fan 18 shifts to the ignition rotation again (S23). , Ignition is done. In the above, the rotation speed of the ignition rotation (for example, 3000 rpm
In general, the post-purge rotation speed is increased (for example, 4650 rpm) to prevent post-boiling after stopping hot water supply and jetting of high-temperature water during re-hot water supply.

[0004]

In the above 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 is introduced from the solar water heater, the required combustion heat quantity (required number) Number) becomes smaller, and the required combustion heat quantity is the minimum combustion capacity of the burner 10 (eg No. 3).
May fall below. In this way, when hot water with a required combustion heat quantity that is less than the minimum combustion capacity of the burner is supplied, even if the burner burns with the minimum combustion heat quantity, the total heat quantity exceeds the necessary heat quantity, and therefore the mixing controller 14 works to generate heat. The exchange flow rate (flow rate of hot water) will be reduced. As a result, the heat exchange flow rate sensor 21 detects 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. Then, after a while, since the hot water supply temperature and the hot water supply temperature are lowered more than necessary because the combustion is stopped this time, the mixing controller 14 again increases the flow rate to the heat exchanger 10 to reach the minimum working water amount for the burner. Then, the rotation speed of the blower fan 18 is reduced to the ignition rotation speed, and combustion is restarted. In this way, every time combustion is started and stopped repeatedly, the rotation speed of the blower fan is repeatedly switched between the high-speed post-purge rotation and the low-speed ignition rotation, which causes a drawback that noise is generated. It was

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

[0006]

In order to achieve the above object, the 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 outlet pipe for hot water heated by the heat exchanger, a bypass pipe for bypassing water from the water inlet pipe to the hot water outlet pipe, and water from the bypass pipe. It has a mixing controller for mixing and adjusting hot water from the hot water pipe, and the minimum working water amount for the burner required for the burner to burn, and is set to a flow rate smaller than the minimum working water amount for the burner, The minimum working water amount for the mixing controller required for driving the mixing controller is set, and the heat exchange flow rate sensor for detecting the flow rate to the instantaneous heat exchanger detects the minimum working water amount for the burner or more. 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 device configured to perform post-purging air blowing by the air-blowing fan, wherein the heat-exchange flow rate sensor detects normal post-purging air blowing when it is less than the minimum working water amount for burners and less than the minimum working water amount for mixing. On the other hand, if the heat exchange flow rate sensor is less than the minimum working water amount for the burner, but it detects more than the minimum working water amount for the mixing controller, then the post purge air should be sent with a lower air flow rate than the normal post purge air flow. It is characterized by having done.

[0007]

According to the above 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 used as the normal high-speed post-purging blast. Only when the amount of working water is less than the minimum amount, the normal high-speed post-purge air is blown. If the water volume is below the minimum working water volume for the mixing regulator, the mixing regulator itself will no longer operate, so that the mixing regulator will not increase the flow rate again above the minimum working water volume for the burner. Therefore, high-speed post-purging air blowing is preferable because post-purging air is normally stopped without being re-combusted and stopped. By performing high-speed post-purge air blowing, post-boiling due to post-heating near the heat exchanger 10 can be prevented, and jetting of boiling water or the like at the time of re-hot water supply can be prevented. on the other hand,
If the amount of water detected by the heat exchange flow rate sensor is less than the minimum working water amount for the burner, but is more than the minimum working water amount for the mixing controller, the mixing controller is still in the state of mixing and adjusting operation. There is still a possibility that the flow rate will be increased above the minimum working water volume for burners, leading to re-ignition. Therefore, the post-purge airflow after the combustion is stopped is not performed at a high rotation speed, but the post-purging air flow is performed at a lower rotation speed, so that the flow rate may become equal to or higher than the minimum working water amount for the burner. Even if it occurs frequently, the difference in rotation speed 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]

EXAMPLES The present invention will be described below based on examples.
FIG. 1 is an overall configuration diagram of the hot water supply apparatus of the present invention, and FIG. 2 is a flow chart for explaining an operation control operation by the controller 30.

Since the entire structure shown in FIG. 1 is the same as the structure described in the section of the prior art, the description thereof will be omitted. However, the controller 30 is newly specified. The controller 30 controls the entire apparatus, and includes a heat exchange flow rate sensor 21, an incoming water temperature sensor 22, a hot water temperature sensor 23, and a hot water supply temperature sensor 2.
4.By inputting information from other sensors, and setting hot water temperature information etc. by a remote controller (not shown), perform necessary calculations and send necessary commands to mixing controller 14, burner 17, blower fan 18 , Send to others.

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

When the post-purging air is started, the coin trawler 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), and if the result is YES. For example, set the blower fan 18 to a normal post-purge rotation speed, for example, 4650 rpm.
After a certain period of time, for example, 3 minutes has elapsed (YES in S8), the post-purge air blowing is ended and the rotation of the air blowing 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),
Rotational speed lower than normal post-purge rotational speed, for example 31
When it is rotated at about 00 rpm and a certain period of time, for example, 3 minutes has passed (YES in S9), the post-purge air blowing is ended and the rotation of the air blowing 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, the steps S8 and S9 are performed.
In the case where the heat exchange flow rate sensor 21 again detects the minimum working water amount for the burner or more before the fixed time (3 minutes) has passed (NO in S11), the controller 30 determines that the blower fan is in operation.
The rotational speed of 18 is switched from the post-purge rotational speed to the ignition rotational speed (S3), and re-ignition is started (S4). It is unlikely that the normal post-purge (S8) proceeds to re-ignition (S3, S4) through step S11. This is because, in this case, the mixing regulator 14 no longer operates, so that the flow rate through the heat exchanger 10 will not increase again unless the hot water supply kerran 16 itself is opened. Therefore, from step S8, most of the air is stopped without being reburned. And in this case, the post-purge rotation speed is a normal rotation consisting of a high rotation speed, so that it is possible to effectively cool the heat around the heat exchanger 12, prevent post-boiling, and start re-hot water supply. It is possible to prevent the high temperature water from being spouted.

On the other hand, during post-purging at a low rotational speed (S
The case of shifting from 9) to re-ignition (S3, S4) through step S11 occurs especially when the set hot water supply temperature is set low. In this case, as a result of the mixing regulator 14 narrowing the flow rate to the heat exchanger 10 side, once the flow rate becomes less than the minimum working water amount for the burner, the combustion of the burner 17 is stopped, but by the stop of the combustion When the hot water temperature drops, the flow rate to the heat exchanger 10 is changed again to the mixing controller 14
Therefore, the flow rate does not become less than the minimum working water amount for the mixing controller, and becomes more than the minimum working water amount for the burner again, and the ignition is restarted. By repeating such a state, switching of air blowing between the post-purge rotation and the ignition rotation is repeated. In the case of the present invention, in preparation for such a case, by setting the rotation speed of the post-purge airflow to a low rotation speed, the rotation speed is close to the ignition rotation speed. Does not occur. Further, since a flow rate equal to or higher than the minimum working water amount for the mixing controller continues to flow, post-boiling does not easily occur even when post-purge at the low rotation speed is completed.

[0014]

According to the present invention, which has the above-described structure,
According to the hot water supply device described in (1), during combustion, when the heat exchange flow rate sensor detects less than the minimum working water amount for the burner and less than the minimum working water amount for mixing, normal post-purge air blowing is performed, while the heat exchange flow rate sensor is used. Is less than the minimum working water amount for the burner, but when the minimum working water amount for the mixing controller is detected, the post purge air is sent with a lower air flow than the normal post purge air flow. In the hot water supply device in which the two minimum working water amounts, that is, the working water amount and the minimum working water amount for the mixing controller, are set, even if the blow purge fan frequently switches between the post-purge rotation and the ignition rotation, the switching causes noise. It can be prevented from occurring.
Moreover, in the normal case, it is possible to prevent the post-boiling from occurring after the end of the post-purge.

[Brief description of 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 Inlet pipe 12 Outlet pipe 13 Bypass pipe 14 Mixing controller 15 Hot water supply pipe 17 Burner 18 Blower fan 21 Heat exchange flow rate sensor 22 Inlet water temperature sensor 23 Outlet water temperature sensor 30 Controller

Claims (1)

[Claims] 1. An instantaneous heat exchanger, a burner for heating the heat exchanger, a blower fan for blowing air to the burner, a water inlet pipe for feeding water to the heat exchanger, and a heat exchanger for heating. It has a hot water outlet pipe for hot water, a bypass pipe for bypassing water from the water inlet pipe to the hot water outlet pipe, and a mixing controller for mixing and adjusting water from the bypass pipe and hot water from the hot water outlet pipe. , And a minimum working water amount for the burner required for the burner to burn, and a minimum working water amount for the mixing controller that is set to a flow rate smaller than the minimum working water amount for the burner and that is required for the mixing controller to drive. If the heat exchange flow rate sensor that detects the flow rate to the instantaneous heat exchanger detects more than the minimum working water amount for the burner, it is ignited after performing the ignition rotation by the blower fan. , Salary When the heat exchange flow sensor detects less than the minimum working water amount for the burner during hot water operation, the hot water supply device performs post-purging air blowing by the blower fan, and the heat exchange flow sensor is the minimum working amount for the burner. When the amount of water is less than the minimum amount of working water for mixing, normal post-purge air is blown, while the heat exchange flow rate sensor detects less than the minimum amount of working water for burners, but detects more than the minimum amount of working water for mixing controllers. If there is, the hot water supply device is characterized in that the post-purging air is blown with a lower air flow rate than the normal post-purging air flow.