JPH11294861A - Forced combusted hot water supplier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forced combusted hot water supplier which is excellent in combustion efficiency and can cope with each kind of exhaust variation, too, with the same combustion state specification, and can also serve for the countermeasure to white smoke, too. SOLUTION: A gas burner 22 is arranged above a heat exchanger 18 where a water supply pipe 14 and a hot water delivery pipe 16 are arranged, and this hot water supplier is equipped with an exhaust fan 36 which compulsively sucks and discharges the combustion waste gas of the gas burner 22 through a draft arranged under the heat exchanger 18. This exhaust fan 36 is attached capably of changing the direction of exhaust of combustion waste gas to frontward, rearward, upward, etc., corresponding to an in-door, installation type, a rear exhaust extension type, etc. in exhaust variation. Moreover, an exhaust hood 32 doubles as a drain pan, and the exhaust pipe of the combustion waste gas is joined to this drain pan, and the exhaust fan 36 is linked to this exhaust pipe 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forced combustion water heater, and more particularly, to combustion by forcibly supplying combustion air to a gas burner and heating water flowing through a water supply pipe with a heat exchanger. The present invention relates to a forced-fired water heater that supplies hot water from a hot water pipe.

[0002]

2. Description of the Related Art Conventionally, as this type of forced combustion water heater, a heat exchanger provided with a water supply pipe and a tapping pipe, a gas burner for heating the heat exchanger, and a supply of combustion air to the gas burner are known. It is generally known to provide a blower fan and heat water flowing through a water supply pipe by a heat exchanger by combustion of a gas burner so that the water flows out of a hot water pipe.

[0003] The arrangement of a heat exchanger, a gas burner, and the like in this type of water heater includes a casing (casing).
Place a heat exchanger inside, and provide a gas burner below it,
Further, a blower fan is provided below the blower, and the air for combustion is forcibly pushed into the gas burner by the blower fan and is fed under pressure (in a pressurized state). After the heat exchanger is heated by the combustion gas of the gas burner, Is configured to be discharged outside through an exhaust hood provided at an upper portion of the casing.

[0004]

However, according to the forced combustion water heater configured as described above, the combustion air is pushed into the gas burner by the forced blast fan, and the combustion gas of the gas burner flows upward. After the heat exchanger is heated, the combustion waste gas flows further upward and is discharged, so it is a so-called `` push combustion type '', so if there is a hole in the heat exchanger due to fin clogging etc. Hot air blows out from the hole, and the body (casing)
Is abnormally heated and there is a risk of fire.

[0005] Further, a combustion product or drain contained in the combustion gas of the gas burner, or a combustion product or drain generated when the combustion gas comes into contact with the heat exchanger drops, so that the flame hole of the gas burner is clogged. Incomplete combustion may occur. Furthermore, due to the configuration of the equipment, it is installed in the door, extended rear exhaust in the door, or forced exhaust (FE
Combustion specifications differ for each exhaust variation such as a forced supply / exhaust type (FF type) and the like, and there is also a problem that manufacturing costs of various water heaters are increased.

The problem to be solved by the present invention is that so-called "combustion air" is sucked under a negative pressure toward a gas burner, and combustion waste gas also flows downward.
It is an object of the present invention to provide a downward combustion type forced combustion water heater. This achieves safe operation by avoiding the danger of fire due to a hole in the heat exchanger, and improves the combustion efficiency by effectively treating the drain, while eliminating the clogging of the burner flame holes. Is intended to contribute to the improvement of production efficiency by supporting the same combustion specifications for gas water heaters of various exhaust variations.

[0007]

In order to solve this problem, a forced combustion water heater according to the present invention comprises a heat exchanger in which a water supply pipe and a tapping pipe are disposed. A gas burner disposed above the heat exchanger for heating the heat exchanger, and a combustion waste gas of the gas burner being forcibly forced through an exhaust hood and an exhaust duct disposed below the heat exchanger. The gist of the invention is to provide an exhaust fan for sucking and discharging.

[0008] According to the forced combustion water heater configured as described above, when the water flowing through the water supply pipe passes through the heat exchanger, it is heated by the gas burner and discharged from the hot water pipe. The air is forcibly sucked and discharged by an exhaust fan through an exhaust hood disposed below the exchanger. As a result, the danger of overheating and fire of the casing (casing) due to the trouble of perforating the heat exchanger is avoided, and the burner flame holes are not clogged with the combustion products.
Further, since the exhaust gas temperature can be lowered to a temperature at which drain is generated, thermal efficiency is greatly improved.

In this case, the exhaust fan is configured to exhaust combustion waste gas according to an exhaust variation corresponding to an in-door installation type, a rear exhaust extension type, a forced exhaust type (FE), or the like. If it can be installed so that the direction can be changed to front, back, upward, etc., various exhaust variations such as in-door type, rear exhaust extension type, and forced exhaust type (FE) of the same combustion specification can be used. Water heaters can be handled with the same combustion specifications.

According to a third aspect of the present invention, when the exhaust hood also serves as a drain pan, the exhaust pipe of the combustion waste gas is connected to the drain pan, and the exhaust fan is connected to the exhaust pipe. The drain falling upward is evaporated by the heat of the combustion waste gas heat, and the remaining amount of the drain is reduced, so that it is not necessary to install a drain pipe.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a gas water heater to which a forced combustion water heater of the present invention is applied, FIG. 2 is a diagram showing a plane cross section of a portion of an exhaust fan shown in FIG. 1, and FIG. It is the figure which showed the side cross section of the part of an exhaust fan.

As shown, this gas water heater 10
The water supply pipe 14 and the tapping pipe 1 are located at lower positions in the appliance body 12.
6 is provided in a state where the heat exchanger 18 is disposed in the combustion chamber 20. A gas burner 22 for heating the heat exchanger 18 is provided above the heat exchanger 18 via a mounting plate 24 with the burner flame hole side facing downward.

A burner cover 26 is attached to the gas burner 22, and the burner cover 26 is provided with a large number of air introduction holes 28 for taking combustion air toward the gas burner 22. Correspondingly, the appliance body 12 is provided with an air supply port (louver) 30 for taking in outside air as combustion air.

On the other hand, at the lower end of the combustion chamber 20 supporting the heat exchanger 18, an exhaust hood 32 for discharging combustion waste gas after heating the heat exchanger 18 by the combustion gas of the gas burner 22 is provided. The exhaust hood 32 has a downward bowl-like shape, and one end of an exhaust pipe 34 is connected to an upper side wall thereof, and the other end of the exhaust pipe 34 is connected to the gas burner 2.
2 is connected to the intake side of an exhaust fan 36 provided at the upper part of the second fan 2. The exhaust pipe 34 is provided with an air introduction hole 37 for introducing air for combating white smoke of the combustion gas and cooling the duct. The exhaust hood 32 also has a drain pan as a tray for drain (combustion products) in the combustion waste gas.

The exhaust fan 36 is attached to a fan mount 38 on the burner cover 26 by bolting, and the outlet 42 of the exhaust fan 36 has an exhaust port 44 opened in the front cover of the combustion chamber 20. Is provided via a baffle plate 46 for dispersing the exhaust gas. still,
A DC motor 48 is connected to the exhaust fan 36.

The water supply pipe 14 is provided with a water flow sensor / water governor 50, and the gas pipe 52 of the gas burner 26 is provided with a main solenoid valve 54 and a gas proportional valve 56. A water flow sensor provided in the water supply pipe 14 and a main solenoid valve 5 provided in the gas pipe 52 of the gas burner 26 are also provided.
4 and the gas proportional valve 56, and D of the exhaust fan 36
The C motor 48 and the like are electrically connected to a burner controller 58 that controls the combustion of the gas water heater 10.

In the gas water heater 10 constructed as described above, when water flows into the water supply pipe 14 by opening a hot water tap (not shown), the exhaust gas is controlled by the burner controller 58 based on a detection signal from the water flow sensor. Fan 3
6 starts rotating by the drive of the DC motor 48. At the same time, the main solenoid valve 54 of the gas burner 22 and the gas proportional valve 5
6 is opened to supply gas to the gas burner 22, and the burner is ignited by an igniter (not shown).

When the ignition operation is completed, the proportional control is started. If there is a difference between the hot water temperature detected by a hot water temperature thermistor (not shown) and the set temperature, the burner controller 58 determines the difference and sends a signal to the gas proportional valve 56. To keep the outlet temperature of the heat exchanger 18 constant by continuously changing the gas amount. Further, the burner controller 58 controls the DC motor 4 of the exhaust fan 36 in accordance with a change in the amount of gas by the gas proportional valve 56.
8, the number of revolutions of the exhaust fan 36 is also changed, and the relationship between the amount of gas and the amount of exhaust, which is equivalent to the amount of combustion exhaust air supplied to the gas burner, Is controlled to be kept constant.

In such a combustion control, the combustion gas of the gas burner 22 flows downward due to the negative pressure of the combustion chamber due to the exhaust operation of the exhaust fan 36, and the combustion gas flows between the heat exchange fins of the heat exchanger 18. Through the exhaust hood 32
And is guided to the intake side of the exhaust fan 36 and discharged from the outlet 42 of the exhaust fan 36.
The air is exhausted out of the appliance through an exhaust port 44 provided in the appliance body 12.

When the combustion chamber of the gas burner 22 is brought into a negative pressure state by the exhausting operation of the exhaust fan 36, outside air is sucked into the appliance main body 12 from an intake port 30 provided in the appliance main body 12, and the air is released from the gas burner. 22 are provided in the burner cover 26.
··· Introduced into the gas burner 22 and used for combustion as combustion air.

By repeating this, the gas burner 22 continues burning with the combustion air introduced from the air introduction holes 28, 28,..., And the water flowing through the heat exchanger 18 is reduced to a predetermined tapping temperature by the combustion gas. The heating is controlled and the hot water is discharged. Further, the combustion waste gas is sucked by the suction operation of the exhaust fan 36 through the exhaust hood 32 provided below the heat exchanger 18 and discharged outside the device, and at that time, the air introduced into the exhaust pipe 34 is introduced. It is diluted by the air introduced from the hole 37 and discharged.

As described above, according to the gas water heater 10,
Since the combustion waste gas of the gas burner 22 passes through the heat exchanger 18 and is sucked from an exhaust hood 32 provided thereunder and discharged out of the apparatus, the combustion chamber 20 supporting the heat exchanger 18 changes over time. Even if a hole is formed, the tool main body 12 is not abnormally overheated without overflow of high-temperature waste gas or flame.

The drain generated in the heat exchanger falls onto the exhaust hood 32, and the burner flame of the gas burner 22 does not become clogged due to the drop of the drain as in the prior art, and provides a healthy combustion. The state is maintained. As a result, the thermal efficiency is remarkably improved. In the field test, the gas water heater of this embodiment has a high efficiency of 95%.

Further, the drain in the combustion waste gas dropped on the exhaust hood 32 is heated by the combustion waste gas continuously sent by the combustion of the gas burner 22 and re-evaporated. The temperature of the combustion waste gas decreases due to the heat of vaporization of the drain,
The exhaust temperature becomes low.

The waste combustion gas discharged by the exhaust fan 36 is diluted by air introduced from the air introduction hole 37 while flowing through the exhaust pipe 34, and is discharged outside the apparatus at a reduced temperature. Therefore, it is not necessary to take measures against the white smoke of the combustion waste gas, and the temperature rise of the drive motor 48 of the exhaust fan 36 can be prevented.

FIGS. 4 to 6 show various exhaust variations to which the present invention is applied. The gas water heater shown in FIG. 4 is of a type installed in a door, and a door 60 provided on the front surface of the appliance main body is provided with an exhaust port 62 for combustion waste gas. It is installed such that the outlet 42 faces 62.

The gas water heater shown in FIG. 5 is of a rear exhaust extension type, in which no exhaust port is provided on the front door of the appliance body, and the outlet 42 of the exhaust fan 36 has a rear side (rear side). The exhaust fan 36 is installed in the instrument body so as to face.

Further, the gas water heater shown in FIG. 6 is of a forced exhaust type (FE type), and an exhaust fan 36 is installed in the appliance body so that an exhaust side 42 of the gas water heater is directed upward.
The exhaust gas is discharged from the exhaust pipe 64 to the outside.

Although various exhaust variations have been described, the same exhaust fan 36 can be installed in the door, extended rear exhaust type, or forced exhaust type (FE) simply by changing its direction.
Equation) can be applied with the same combustion specifications. Although not shown, it goes without saying that the present invention can be applied to a gas water heater of a forced supply / exhaust type (FF type) with a simple structure.

The present invention is not limited to the above-described embodiment at all, and does not depart from the gist of the present invention.
Various modifications are possible. For example, in the above embodiment, a water heater such as a gas instantaneous water heater was described, but it is needless to say that this can be applied to various water heaters such as a bath water heater. Also, not necessarily combustion control feedback (FB)
Feed forward (F)
F) It naturally applies to the control type.

[0031]

The forced combustion water heater according to the present invention has a gas burner installed above the heat exchanger, and the combustion waste gas after heating the heat exchanger with the combustion gas from the gas burner is placed below the heat exchanger. The exhaust fan is forcibly sucked and exhausted through an exhaust hood and an exhaust duct provided, and air for burning the gas burner is sucked into the combustion chamber from the outside by utilizing the fact that the combustion chamber becomes negative pressure by the exhaust fan. It is intended to be used for combustion.

Therefore, according to this forced combustion water heater,
Combustion products can be greatly improved without the combustion products clogging the flame holes of the gas burner and causing incomplete combustion, and the fin clogging of the heat exchanger does not lower the heat exchange rate.

According to a second aspect of the present invention, the exhaust fan has the same combustion specifications and is installed in the door, the rear exhaust extension type,
Applicable to forced exhaust type (FE type), forced supply / exhaust type (FF type), etc., unification of production specifications, efficiency of production line, and forced air blowing corresponding to various exhaust variations There is an advantage that the development effort required to provide the fan can be reduced, the development cost can be significantly reduced, and the development speed can be promoted.

Further, as in the third aspect of the present invention, by using the exhaust hood for combustion waste gas provided below the heat exchanger as a drain pan, the drain in the combustion waste gas stored therein is burned. Since the waste gas is evaporated by heat and discharged at a low exhaust gas temperature, it is not necessary to take measures against the white smoke of the combustion waste gas, and the economic effect is great, and it is extremely useful in industry.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a forced combustion water heater according to one embodiment of the present invention.

FIG. 2 is a plan sectional view showing an exhaust fan portion of the water heater shown in FIG.

FIG. 3 is a side sectional view showing a part of an exhaust fan of the water heater shown in FIG. 1;

FIG. 4 is a diagram showing an in-door type water heater as an exhaust variation of the forced combustion water heater.

FIG. 5 is a view showing a rear exhaust extension type water heater as an exhaust variation of the forced combustion water heater.

FIG. 6 is a view showing an exhaust variation (FF type) of a forced combustion water heater as an exhaust variation of the forced combustion water heater.

[Explanation of symbols]

 Reference Signs List 10 gas water heater 14 water supply pipe 16 tapping pipe 18 heat exchanger 20 combustion chamber 22 gas burner 32 exhaust hood 34 exhaust pipe (exhaust duct) 36 exhaust fan 58 burner controller

Claims (3)

[Claims] 1. A heat exchanger provided with a water supply pipe and a tapping pipe, a gas burner disposed above the heat exchanger for heating the heat exchanger, and a combustion waste gas from the gas burner. A forced combustion water heater comprising an exhaust hood disposed below the heat exchanger and an exhaust fan forcibly sucking and discharging through an exhaust duct above the heat exchanger. 2. The exhaust fan according to claim 1, wherein an exhaust variation corresponds to an in-door installation type, a rear exhaust extension type, a forced exhaust type (FE), or the like.
The forced combustion water heater according to claim 1, wherein the water heater is mounted so as to be changeable upward or the like. 3. The forced combustion water heater according to claim 1, wherein the exhaust hood also has a drain pan.