JPH0328264Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an air supply device for forcibly sending air to a combustion chamber in a water heater such as an instantaneous water heater.

<Prior art and its problems> Conventional air supply devices for water heaters supply the required amount of air by changing the rotational speed of the air supply blower depending on the gas pressure of the gas burner in the combustion chamber. In other words, since the rotation speed of the blower was controlled only by gas pressure, even if the air supply situation inside the combustion chamber changed due to other external influences, the blower could not be controlled to follow this change. Nakatsuta. Therefore, for example, when a water heater is being burned at a low capacity (low gas pressure) and air is blown into the combustion chamber from the exhaust port, the air flow inside the combustion chamber changes and the burner section There was an inconvenience that there was a lack of air, resulting in non-combustion or the flame going out.

Therefore, the present invention solves the above-mentioned drawbacks of the conventional technology, and makes it possible to change the amount of air supply depending on the ventilation condition inside the combustion chamber, and even if wind enters from the outside, the flame will not go out or will not burn. The purpose of the present invention is to provide an air supply device for a water heater that does not become loose.

<Means for solving the problem> The present invention is devised to keep not only the gas pressure of the gas burner but also the pressure gradient within the combustion chamber constant, and to maintain the air flow at a constant flow rate regardless of external fluctuation factors. Measures are taken to ensure that the fuel moves inside the combustion chamber (from the bottom to the top). That is, in the present invention, a burner B is disposed in a combustion chamber 12 covered by a case 11, and a water pipe 14 for heat exchange is disposed above the burner B, and an exhaust hole 16 for the burned gas is provided in the upper part of the case 11. This is an air supply device for a water heater, in which a forced air supply duct 21 is connected to the lower part of the case 11, and includes a blower 23, and a forced air supply duct 21 connected to the lower part of the case 11.
3 to the combustion chamber 12 through the duct 21, and a pair of pressure sensors 24, 25 disposed at intervals within the air supply passage 22.
and a controller 26 that receives pressure information from the pair of pressure sensors 24 and 25 and controls the rotation speed of the blower, and has a pair of pressure sensors 24 and 25 arranged at a constant interval in the air supply passage 22. The present invention is characterized in that the rotational speed of the blower 23 is controlled in such a direction that the difference in air pressure between the two sensor positions obtained by the pressure sensors 24 and 25 approaches a predetermined reference pressure difference.

<Function> The difference in air pressure between a pair of pressure sensors in the air supply passage is determined in advance as a reference pressure difference, corresponding to the state in which optimal combustion is achieved for each gas pressure of the burner to be adjusted. By storing the reference pressure difference in advance in the controller, the pressure difference between the pair of pressure sensors and the reference pressure difference during actual operation can be constantly compared and the pressure difference can be made to approach the reference pressure difference. Change the rotation speed of the blower. When wind or the like enters the combustion chamber through the exhaust hole and prevents the upward movement of air within the combustion chamber, the pressure within the combustion chamber increases, and as a result, the pressure difference between the pressure sensors becomes smaller than the reference pressure difference. The control then senses this and increases the speed of the blower to return the pressure difference between the pressure sensors to the reference pressure difference. Therefore, since the air always rises within the combustion chamber at a predetermined speed with a constant pressure difference, that is, a constant pressure gradient, extinguishing of flame and non-combustion due to external influences are prevented.

<Example> The figure is an overall configuration diagram of an apparatus showing an example of the present invention.

The water heater 10 has a combustion chamber 12 inside a case 11.
The combustion chamber 12 has a burner 13 and a finned water pipe 14 for heat exchange arranged above the burner 13. The burner 11 has a gas pipe nozzle 1.
5 is coming. An exhaust hole 16 is provided in the upper part of the case 11 to exhaust gas after combustion. Further, an air supply duct 21 is connected to the lower part of the case 11 to feed air into the combustion chamber 12. The air supply device includes the duct 21, a blower 23 that sends air to the air supply passage 22 in the duct 21, a pair of pressure sensors 24 and 25 arranged at a fixed interval within the air supply passage 22, and controls each of these parts. It has a controller 26 etc. to perform the operation. The gas pipe is opened by operating the controller 26, gas is ignited in the burner 13, and the blower 23 is driven. When the burner 13 is ignited, air is forcibly supplied into the combustion chamber 12 from the blower 23 through the air supply passage 22, and the combusted gas rises and is exhausted from the exhaust hole 16.
The water sent to the water pipe 14 is heated in the combustion chamber 12 and comes out as hot water.

The controller 26 has a built-in microcomputer, which obtains in advance the air pressure difference between the pair of pressure sensors 24 and 25 under conditions that provide optimum combustion for each gas pressure to be adjusted, and calculates this difference. It is stored in the microcomputer. That is, for some gas pressures to be adjusted, there is always a situation within the combustion chamber 12 in which the most effective combustion takes place, and there is a situation between the first pressure sensor 24 and the second pressure sensor 25 that corresponds to that situation. There is also an optimum air pressure difference. Therefore, the optimal pressure difference between the sensors 24 and 25 is stored in advance in the microcomputer for each gas pressure as a reference pressure difference. Then, the pressure difference is constantly calculated by a microcomputer from the air pressure information input from the first and second pressure sensors 24 and 25, respectively, and the obtained actual pressure difference is used as the reference pressure difference for the selected gas pressure. A command corresponding to the result is output to the blower 23. Now, for example, if wind blows in from the exhaust hole 16 and the movement of the upward airflow inside the combustion chamber 12 deteriorates,
Since the pressure within the combustion chamber 12 increases, the pressure detected by the second pressure sensor 25 also increases, and thus the pressure difference between the first and second pressure sensors 24, 25 becomes smaller than the reference pressure difference. Then, the controller 26 issues a command to the blower 23 to increase the rotation speed of the blades, and as a result, the blower 22
The amount of air blown by the first pressure sensor 24 is increased, and the pressure detected by the first pressure sensor 24 increases.
and the pressure difference between the second pressure sensors 24 and 25 approaches the reference pressure difference. That is, by arranging the two pressure sensors 24 and 25 at a constant interval, the computer can control the combustion state in the combustion chamber 12 to always be constant.

<Effects> The present invention has the above-mentioned configuration, and a pair of pressure sensors are arranged at a fixed interval in the air supply passage.
The fan's rotational speed is always controlled so that the air pressure difference between the pressure sensor positions matches the reference pressure difference, so wind is blown into the combustion chamber from the outside and changes its combustion state. Even if an attempt is made to do so, air is immediately supplied in a direction that cancels out the change. Therefore, the inside of the combustion chamber is always maintained in an optimal combustion state, and the flame is not extinguished by wind blowing from the outside or a non-combustion state occurs, and the combustion chamber can always be operated in an optimal combustion state.

[Brief explanation of the drawing]

The figure is an overall configuration diagram of an apparatus showing an embodiment of the present invention. 10: water heater, 11: case, 12: combustion chamber, 13: burner, 14: water pipe, 16: exhaust hole, 21: air supply duct, 22: air supply passage, 23:
Blower, 24, 25: Pressure sensor, 26: Controller.

Claims (1)

[Scope of utility model registration request] A burner 1 is installed in a combustion chamber 12 covered by a case 11.
3 and a water pipe 14 for heat exchange is arranged above it, an exhaust hole 16 for the burned gas is provided in the upper part of the case 11, and a duct 21 for forced air supply is provided in the lower part of the case 11. An air supply device for the connected water heater, which includes a blower 23;
An air supply passage 22 leading from the blower 23 to the combustion chamber 12 through the duct 21, and a pair of pressure sensors 2 disposed at intervals within the air supply passage 22.
4, 25, and a controller 26 that receives pressure information from the pair of pressure sensors 24, 25 and controls the rotation speed of the blower 23, and is arranged at a constant interval in the air supply passage 22. The rotation speed of the blower 23 is controlled in a direction in which the difference in air pressure between the two sensor positions obtained by the pair of pressure sensors 24 and 25 approaches a predetermined reference pressure difference. Air supply equipment for water heaters.