JPH045856Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Purpose of the invention] (Field of industrial application) This invention relates to a domestic water heater using an all-primary premixing method, and aims to simplify and downsize it while reducing the noise generated during combustion. The present invention relates to a domestic water heater using an all-primary premixing method that can reduce the flame temperature and ensure a quiet and stable flame.

(Conventional technology) The conventional all-primary premixing method home water heater is
For example, a gas instantaneous water heater has been proposed in Japanese Utility Model Application Publication No. 60-146250.

This type of home water heater uses a Shirotskov fan, which is a type of centrifugal blower, to mix the air necessary for combustion before sending the fuel gas to the gas burner, and performs high-load combustion in a sealed combustion chamber. The overall structure is considered to be a cylindrical shape with only two places, the air intake and the exhaust port, open. The distance from the flame port to the exhaust port is longer than the distance from the burner to the exhaust port.

(Problems to be solved by the invention) <Problems with the conventional technology> However, in the case of a high-temperature heat source during combustion within a cylinder, when the heat source is located upstream of the cylinder,
In the case of a low-temperature heat source, when the heat source is located on the downstream side of the cylindrical body, self-excited vibrations of the air column, which are relatively dull, occur, producing noise.

Therefore, the above-mentioned phenomenon occurs even in the domestic water heater.

In other words, the heat source of this household hot water heater is the flame spout, which is a high-temperature heat source, and the distance from the flame spout to the exhaust port is shorter than the distance from the air intake of the centrifugal blower to the flame mouth. Since this is longer, the structure is such that the high temperature heat source is placed on the upstream side of the cylindrical shape. Therefore, during combustion, the above-mentioned air column self-excited vibration generates noise, which is noisy, and there is a problem that a stable flame cannot be obtained due to this vibration.

<Technical Issues> Therefore, in view of the above-mentioned problems, this invention aims to simplify and downsize the structure of a household water heater using the all-primary premixing method, while also reducing the self-excitation of the air column generated during combustion. It was devised to eliminate noise caused by vibration and to obtain a stable flame.

[Structure of the invention] (Means for solving the problem) This invention consists of a centrifugal blower, a gas supply nozzle arranged in the air intake part of the centrifugal blower, and air and fuel sent out from the air outlet of the centrifugal blower. A pressure equalization section that further stirs, disperses, and pressure equalizes the mixed gas with gas, a combustion flame face plate that burns the mixed gas from the pressure equalization part, and a heat exchanger placed opposite to this combustion flame face plate. In a domestic water heater using the all-primary premixing method, which consists of an exchanger and an exhaust port, and which is sealed except for the air intake and exhaust port, and takes in all the air necessary for combustion when gas is supplied, the combustion flame face plate By extending the flow path from the air intake section to the air intake section by extending a tube into the air intake section, or by protruding a partition plate appropriately inside and making it meander, the flow path from the combustion flame face plate, which is a heat source, to the atmosphere can be made. The above-mentioned problem is solved by making the distance of the low-temperature flow path from the combustion flame face plate, which is a heat source, to the air intake part longer than that of the high-temperature flow path to the exhaust port.

(Function) The all-primary premixing type domestic water heater according to this invention is designed to air air from the combustion outlet face plate of the all-primary premixing type domestic water heater, which is completely sealed except for the air intake and exhaust port. By extending the flow path to the air intake part into the air intake part, which is extremely compact and simple in terms of structure, or by protruding a partition plate as appropriate inside and making it meander, it is possible to The distance of the low-temperature flow path from the combustion burner faceplate, which is the heat source, to the air intake is made longer than the high-temperature flowpath from the burner faceplate to the exhaust port to the atmosphere, so that it is affected by the sound wave velocity at high temperatures. To eliminate resonance by arranging a combustion flame face plate part, which is a high-temperature heat source, on the downstream side of a domestic water heater having a cylindrical shape as a whole.

Furthermore, by forming the air column self-excited vibrations that occur when a heat source is placed upstream of the cylinder, it is eliminated.

(Embodiments) Hereinafter, embodiments of this invention will be described with reference to the drawings.

That is, the reference numeral 1 shown in the figure is an all-primary premixing type household water heater, which uses a centrifugal blower 2 to further stir the mixed gas of air and fuel gas sent out from the blower outlet 5 of the centrifugal blower 2. a pressure equalization section 7 made up of a plurality of dispersion and pressure equalization plates 6 for dispersing and equalizing pressure;
A combustion flame face plate 8 for combusting the mixed gas from the pressure equalization part 7, a heat exchanger 9 disposed facing the combustion flame face plate 8, and a heat exchanger 9 disposed in order from the bottom to the top. It consists of an exhaust port 10 arranged.

Further, this domestic water heater 1 is sealed by a case 11 except for the air intake section 3 and the exhaust port 10, and is configured to take in all the air necessary for combustion when gas is supplied.

The home water heater 1 includes a centrifugal blower 2.
An auxiliary cylinder 12 is installed downward covering the whole,
The opening at the lower end of this auxiliary cylinder 12 is formed as the air intake part 3, and the combustion flame face plate 8 is a heat source.
The distance of the low-temperature flow path from the combustion flame port face plate 8, which is a heat source, to the air intake part 3 is formed to be longer than the distance of the high-temperature flow path from the combustion outlet face plate 8 to the exhaust port 10. Moreover,
The gas supply nozzle 4 is inserted into the auxiliary cylinder 12 from the position of the centrifugal blower 2 in the auxiliary cylinder 12, and all air is taken in from the air intake part 3.

When formed in this way, when the entire domestic hot water heater 1 is considered as a cylinder, when the mixed gas is combusted in the 8 parts of the combustion face plate, the 8 part of the combustion face plate becomes a high-temperature heat source. When looking at the whole domestic water heater 1, this high-temperature heat source is placed on the downstream side of the cylindrical body, which eliminates the generation of noise and resonance due to the self-excited vibration of the air column. There is no adverse effect on the flame, and a stable combustion state can be ensured.

On the other hand, as another embodiment, as shown in FIG. 7, an appropriate number of partition plates 13 (in the case of illustration, two partition plates 13) are provided alternately protruding from both sides laterally from the inner surface of the case 11 so that the flow path of the mixed gas is meandering, and the heat source The low-temperature flow path from the combustion flame face plate 8, which is a heat source, to the air intake part 3 is formed to be longer than the high-temperature flow path from the combustion flame face plate 8, which is a heat source, to the exhaust port 10.

Then, if the meandering flow path is extended by the partition plate 13 and considered as a cylinder, the high-temperature heat source will be placed downstream of the cylinder, as in the above-mentioned embodiment, and the air column will be The generation of noise and resonance due to self-excited vibrations is eliminated, and the adverse effects on the flame due to self-excited vibrations of the air column are also eliminated, making it possible to ensure a stable combustion state.

Note that the reference numeral 14 in the figure is a spark plug. or,
In the case of the structure in the other embodiments described above, the linear distance from the combustion flame face plate 8 to the air intake part 3 is longer than the distance from the combustion flame face plate 8 to the exhaust port 10. Alternatively, it is preferable to keep them at the same distance.

The domestic water heater 1 formed in this way is designed to eliminate the self-excited vibration of the air column, which occurs due to the principle of vibration of the air column due to heat, as described below in the problems of the conventional technology. It was formed.

That is, when the gas flowing inside the cylinder is locally heated by the heat source, self-excited vibrations occur within the air column. The vibration generated by this vibration is relatively close to a pure tone, and its frequency is approximately equal to the resonant frequency of the air column inside the cylinder.

The occurrence of this air column self-excited vibration differs depending on the type of heat source and its location.

In other words, in order to generate fundamental vibrations in the air column inside a uniform cylinder with both ends open, a high-temperature heat source must be present upstream of the central cross section of the cylinder, and a low-temperature heat source must be downstream from the central cross-section of the cylinder. are most pronounced at the central position within each range. Conversely, when a high-temperature heat source is located on the downstream side of the cylindrical body, and a low-temperature heat source is located on the upstream side, the heat source not only does not help generate vibrations, but also can have a positive damping effect.

This invention reversely utilizes this principle in a domestic water heater and forms it like the structure described above to eliminate the noise caused by self-excited vibration of the air column and the adverse effects on the flame.

It should be noted that the structure is not limited to the structure shown in the above-described embodiment as long as the combustion flame face plate 8, which is a high-temperature heat source, is arranged on the downstream side when the entire domestic water heater 1 is made into a cylinder. Needless to say.

[Effect of the invention] This invention configured as described above has a centrifugal blower 2
and a gas supply nozzle 4 arranged in the air intake part 3 of the centrifugal blower 2, and a pressure equalization unit that further stirs, disperses, and equalizes the mixed gas of air and fuel gas sent out from the air outlet 5 of the centrifugal blower 2. part 7, a combustion flame face plate 8 for burning the mixed gas from the pressure equalization part 7,
It consists of a heat exchanger 9 placed opposite to this combustion flame face plate 8 and an exhaust port 10, and everything except the air intake part 3 and the exhaust port 10 is sealed, and all the air necessary for combustion is supplied when gas is supplied. Since the domestic hot water supply apparatus 1 is of an all-primary premixing system, the domestic hot water supply apparatus 1 can be considered to be a cylindrical body with only two openings, the air intake part 3 and the exhaust port 10.

Therefore, by making the distance of the low-temperature flow path from the combustion flame face plate 8, which is a heat source, to the air intake part 3 longer than the high-temperature flow path from the combustion flame face plate 8, which is a heat source, to the exhaust port 10, Because the high-temperature heat source is placed on the downstream side of the domestic water heater 1, which is considered to be an entirely cylindrical body, it does not have a structure in which the high-temperature heat source is placed on the upstream side, unlike the conventional all-primary premix water heater. It is possible to eliminate the generation of noise due to resonance and self-excited vibration of the air column, and the negative effects on the flame due to self-excited vibration of the air column, and it is possible to ensure a quiet and stable combustion state. Furthermore, the overall structure has been significantly improved by extending the tube to the air intake part 3 or protruding the partition plate 13 inside to make the flow path meandering and elongate. Since the purpose can be sufficiently achieved even without this, the purpose of miniaturization by adopting the all-primary premixing method is not hindered, and the manufacturing cost can be reduced without leading to an increase in cost.

As explained above, according to this invention, it is possible to simplify the structure and downsize the all-primary premixing type domestic water heater, while eliminating noise caused by the self-excited vibration of the air column generated during combustion, thereby achieving stable water heating. Since flame can be obtained, it has practical effects such as being able to provide a quiet and efficient home water heater at a low cost.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view of an embodiment of this invention, and FIG. 1 is a front sectional view of another embodiment. 1...Home water heater, 2...Centrifugal blower, 3
...Air intake part, 4...Gas supply nozzle, 5...
Air blowing outlet, 6...Dispersion pressure equalization plate, 7...Pressure equalization part, 8
... Flame face plate for combustion, 9 ... Heat exchanger, 10 ...
Exhaust port, 11... Case, 12... Auxiliary tube, 13
...Partition board.

Claims (1)

[Scope of utility model registration request] A centrifugal blower, a gas supply nozzle arranged in an air intake part of the centrifugal blower, and a pressure equalization part that further stirs, disperses, and equalizes the pressure of the mixed gas of air and fuel gas sent out from the blowing outlet of the centrifugal blower; a combustion flame face plate that burns the mixed gas from the pressure equalization section; a heat exchanger disposed opposite to the combustion flame face plate;
In a domestic hot water heater using the all-primary premixing method, where all air intake and exhaust ports are sealed except for the air intake and exhaust ports, and all the air necessary for combustion is taken in when gas is supplied, the air intake from the combustion flame face plate is By extending the flow path to the air intake part by extending a tube into the air intake part, or by protruding a partition plate as appropriate inside and making it meander, the flow path can be made from the combustion flame face plate, which is the heat source, to the exhaust port to the atmosphere. An all-primary premixing type domestic water heater, characterized in that the distance of the low-temperature flow path from the combustion flame face plate, which is the heat source, to the air intake section is longer than that of the high-temperature flow path.