JP2004162947A - Hot air heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot air heater preventing the increase of a discharge amount of nitrogen dioxide in the hot air to be discharged into a room by making a flow dividing plate be hardly heat-deformed. <P>SOLUTION: A holding means 54 is mounted for holding a part of a downstream end 53 of the flow dividing plate 5 to retain a cross-sectional area of a combustion gas passage 216 and an air passage 42. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hot air heater provided with a flow dividing plate so that combustion gas from a combustion case is not rapidly cooled.
[0002]
[Prior art]
A conventional warm air heater has a housing provided with, for example, an outlet and an inlet. Inside this housing, a combustion case having a gas burner, and disposed below this combustion case, supplying air necessary to burn the fuel gas supplied to the gas burner and from the combustion gas from the gas burner and the intake port A blower fan that mixes the air sucked into the housing and blows warm air from the outlet into the room through the outlet is provided, and a blowing path of a warm air heater that communicates from the inlet to the outlet is formed.
[0003]
Here, if the combustion gas from the gas burner is immediately mixed with the air sucked from the intake port, the high-temperature combustion gas is rapidly cooled, and nitrogen monoxide of nitrogen oxides contained in the combustion gas is converted into nitrogen dioxide. Ratio increases. Since this nitrogen dioxide is highly toxic, it is necessary to reduce the emission of nitrogen dioxide in the warm air exhausted indoors.
[0004]
For this reason, in the conventional warm air heater, a flow dividing plate is provided that partitions the air sucked into the housing from the intake port by the operation of the blower fan and the combustion gas discharged from the combustion cylinder until a predetermined distance flows, By exchanging heat between the combustion gas and the air through the flow dividing plate, lowering the temperature of the combustion gas and raising the temperature of the air, so that the combustion gas is not rapidly cooled at the junction of the combustion gas and the air. (Patent Document 1).
[0005]
The flow dividing plate is attached without leaving a gap between the rear surface of the combustion case. In this case, since the high-temperature combustion gas flows inside the flow dividing plate and the room temperature air flows outside, the downstream end of the flow dividing plate is slightly deformed by thermal expansion due to a difference in the expansion amount based on the temperature difference (hereinafter, referred to as “ Thermal deformation ”). In particular, when the lateral width is long, the dimension that warps due to thermal deformation increases.
[0006]
By the way, in order to suppress the amount of nitrogen dioxide emitted into the room during the operation of the hot air heater, it is preferable to lower the combustion gas to a predetermined temperature before mixing with the air. It is conceivable to increase the length of the flow dividing plate so that the downstream end of the flow dividing plate where the air and the air merge extends to the front of the combustion case (Patent Document 1).
[0007]
[Patent Document 1]
JP-A-8-327152 (for example, claims)
[0008]
[Problems to be solved by the invention]
By the way, if the temperature difference between the combustion gas and the air is large, the flow dividing plate is deformed by the difference in the expansion amount between the front surface and the back surface of the flow dividing plate. In this case, when the area of the flow dividing plate is increased as described above, the difference in the amount of expansion increases, and the flow dividing plate is greatly deformed. When the cross-sectional area of the combustion gas passage between the flow dividing plate and the front plate of the combustion casing is reduced by the deformation of the flow dividing plate, the flow of the combustion gas is suppressed, and the surface temperature of the gas burner is increased, so that nitrogen dioxide in the combustion gas is reduced. The generation amount increases, and the generation amount of nitrogen dioxide in the warm air discharged into the room increases.
[0009]
Conversely, when the cross-sectional area of the combustion gas passage between the distribution plate and the front plate of the combustion casing increases, the cross-sectional area of the air passage between the distribution plate and the inner surface of the casing decreases, and the amount of air flowing through this air passage When the heat exchange between the combustion gas and air through the flow dividing plate becomes insufficient, the combustion gas is quenched at the junction, the rate of conversion of nitric oxide to nitrogen dioxide increases, and the air is discharged indoors. The emission of nitrogen dioxide in hot air increases.
[0010]
In view of the above, the present invention provides a warm air heater that makes it difficult to thermally deform a flow dividing plate and suppresses an increase in the amount of nitrogen dioxide in warm air discharged indoors. Is the subject.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, a hot air heater of the present invention includes, in a housing provided with an air outlet and an air inlet, a combustion housing having a gas burner and a blower fan disposed below the combustion housing. A flow dividing plate is provided which partitions the air sucked into the housing from the intake port by the operation of the blower fan and the combustion gas discharged from the combustion cylinder until a predetermined distance flows, and the combustion gas and the air are separated through the flow dividing plate. After exchanging heat, in a warm air heater that mixes and blows warm air into the room from the outlet, the flow dividing plate is not deformed during operation so that the flow of the combustion gas and the air is not hindered. Characterized in that a holding means for holding a part of the downstream end is provided.
[0012]
According to the present invention, the high-temperature combustion gas inside the flow dividing plate during operation, even if the flow dividing plate is thermally deformed by the flow of room temperature air outside, the downstream end of the flow dividing plate is held, The cross-sectional area of the air passage between the flow dividing plate through which the room temperature air flows and the inner surface of the housing is maintained. Therefore, on the one hand, an increase in the amount of nitrogen dioxide in the combustion gas due to an increase in the surface temperature of the gas burner due to the thermal deformation of the flow dividing plate is suppressed, and on the other hand, the combustion at the junction of the combustion gas and the air An increase in the rate of conversion of nitric oxide to nitrogen dioxide due to the quenching of the gas is suppressed. Therefore, it is possible to suppress an increase in the emission amount of nitrogen dioxide in the hot air and to secure a stable flow of the hot air from the outlet.
[0013]
In this case, the holding means has, for example, a protrusion provided at a downstream end of the flow dividing plate at a substantially central portion in the width direction of the flow dividing plate, and an opening with which the protrusion engages, and the holding means is fixed to the housing. What is necessary is just to comprise from a member.
[0014]
By the way, in a hot air heater, a flame detecting means such as a frame rod or a thermocouple or an ignition means such as an electrode for igniting a gas burner may be provided in the combustion casing to detect the presence or absence of a flame in the combustion casing. is there. In this case, for example, in order to facilitate the attachment and detachment of the ignition means when maintaining or replacing the ignition means, the front face of the combustion casing is traversed through the mixed gas passage located downstream of the downstream end of the distribution plate where the combustion gas and the air merge. The ignition means is inserted from.
[0015]
When the flame detecting means or the ignition means is provided in this manner, if the hot air in the mixed gas passage is directly blown, the flame detecting means or the ignition means is overheated. For this reason, the flame detecting means or the ignition means is covered with a protective cover. The protective cover is fixed to the housing.
[0016]
In this case, if the holding member is a protective cover that covers the flame detecting means for detecting the presence or absence of the flame of the gas burner or the ignition means for igniting the gas burner, the number of parts can be reduced and the cost can be reduced.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Referring to FIG. 1, reference numeral 1 denotes a hot air heater of the present invention. The warm air heater 1 has a housing 11 having an outlet 11a on the front and an inlet 11b on the rear. Inside the housing 11, a combustion housing 2 having a gas burner 21 and a blower fan 3 disposed below the combustion housing 2 are provided.
[0018]
The gas burner 21 is an all-primary combustion type that is effective in suppressing the emission of nitrogen oxides such as nitric oxide and nitrogen dioxide, and has a gas supply pipe (not shown) provided with a proportional control valve. The burner main body 21a has a fuel gas / air suction port 211 facing a gas injection nozzle (not shown) mounted on the fuel injection port, and a mixing pipe section 212 communicating with the suction port 211. On the open upper surface of the burner main body 21a, a ceramic flame port plate 213 in which a plurality of flame ports are arranged in a row via a distribution plate (not shown) is mounted. The upper space of the flame port plate 213 is surrounded by a combustion cover 214. Further, the combustion case 2 is arranged in a partition wall 4 fixed to the inside of the case 11 so as to communicate with the intake port 11b and form a space for accommodating the combustion case 2.
[0019]
On the other hand, the blower fan 3 has a housing 31 mounted on the lower surface of the partition wall 4. Inside the housing 31, a cross-flow type rotation connected to a motor (not shown) capable of controlling the rotation speed is provided. The blade 32 is arranged. The combustion case 2 and the blower fan 3 communicate with each other via a vent 41 provided on the lower surface of the partition wall 4.
[0020]
Thus, when the blower fan 3 is rotated, the combustion air is supplied to the gas burner 21 and the combustion gas from the exhaust chamber 215 of the combustion case 2 surrounded by the combustion cover 214 and the intake port 11 b to the case 11. The blown air is mixed with the sucked air to form a blowing path for blowing warm air into the room through the air outlet 11a.
[0021]
By the way, if the combustion gas from the combustion case 2 is immediately mixed with the air sucked from the intake port 11b, the high-temperature combustion gas is rapidly cooled, and nitrogen monoxide among nitrogen oxides contained in the combustion gas is converted into nitrogen dioxide. The ratio to be converted increases. For this reason, a flow dividing plate 5 is provided which partitions the air sucked into the housing 11 from the intake port 11b by the operation of the blower fan 4 and the combustion gas discharged from the combustion cylinder 2 until they flow by a predetermined distance. Heat is exchanged between the combustion gas and the air via the plate 5 to lower the temperature of the combustion gas and increase the temperature of the air so that the combustion gas is not rapidly cooled at the junction of the combustion gas and the air. .
[0022]
Referring to FIGS. 2 and 3, in the present embodiment, since the temperature of the combustion gas is high, in order to cool the combustion gas to a predetermined temperature, the upper part of exhaust chamber 215 is entirely covered and the combustion chamber is heated. The flow dividing plate 5 was formed by bending so as to extend to the front surface of the cylinder 2. In this case, at each end of the flow dividing plate 5 in the width direction, four folded portions 51 are formed. Then, the flow dividing plate 5 is fixed to the upper edge of the rear plate 2a of the combustion case 2 via a flange 52 provided at the upstream end of the dividing plate 5 without any gap, and each of the folded portions 51 is fixed to the partition 4 to mount the dividing plate 5. . Note that the width of the flow dividing plate is set according to the number of hot air heaters 1.
[0023]
Further, an electrode 6 is provided as an ignition means for igniting the gas burner 21 in the combustion housing 2. In this case, in order to facilitate the attachment and detachment of the electrode 6 when the electrode 6 is maintained or replaced, the electrode 6 crosses the mixed gas passage 7 on the downstream side of the downstream end 53 of the flow dividing plate 5 where the combustion gas and the air merge. The electrode 6 is inserted from the front (see FIG. 1).
[0024]
When the electrode 6 is provided in this manner, if the hot air in the mixed gas passage 7 blows directly to the electrode 6, the electrode is overheated. For this reason, the electrode 6 is covered with a protective cover 8 as shown in FIG. The protective cover 8 is fixed to the partition 4 via a mounting portion 81 provided at one end thereof.
[0025]
By the way, when the hot air heater 1 is operated, the high temperature combustion gas flows inside the distribution plate 5 and the room temperature air flows outside the distribution plate 5, so the expansion amount between the front surface and the back surface of the distribution plate 5 due to this temperature difference. Due to the difference, the flow dividing plate 5 is thermally deformed. Here, when the flow dividing plate 5 having a wide width is used, in addition to the increase in the amount of expansion, the width between the folded portions 51 supporting the flow dividing plate 5 is wide, so that the strength is reduced and the flow dividing plate 5 is easily deformed. . Therefore, in the present embodiment, the width of the flow dividing plate 5 is increased and its length is increased to increase the area thereof, and the temperature difference is increased by using the gas burner 21, which is combined with the distribution plate 5. 5 undergoes large thermal deformation.
[0026]
Due to the thermal deformation of the distribution plate 5, the sectional area of the combustion gas passage 216 between the front plate 2b of the combustion housing 2 and the distribution plate 5 decreases (the sectional area of the air passage 42 between the partition wall 4 and the distribution plate 5 decreases). Increase), the flow of the combustion gas is suppressed, and the surface temperature of the gas burner 21 rises, so that the amount of generated nitrogen oxides such as nitrogen monoxide and nitrogen dioxide in the combustion gas increases, and the temperature discharged into the room increases. The emission of the nitrogen oxides in the wind increases. Therefore, the generation amount of nitrogen dioxide increases, and the emission amount of nitrogen dioxide in the warm air increases.
[0027]
Conversely, the cross-sectional area of the combustion gas passage 216 between the front plate 2b of the combustion housing 2 and the flow dividing plate 5 increases due to the thermal deformation of the flow dividing plate 5 (the disconnection of the air passage 42 between the partition 4 and the flow dividing plate 5). When the area decreases, the amount of air in the air passage 42 decreases, so that heat exchange between the combustion gas and the air via the flow dividing plate 5 becomes insufficient, and the mixed gas passage 7 in which the air and the combustion gas merge is formed. The combustion gas is quenched by the air, the rate of conversion of nitrogen monoxide to nitrogen dioxide increases, the amount of nitrogen dioxide in the warm air discharged into the room increases, and the amount of air flowing through the air passage 42 decreases. As a result, the total amount of air taken into the warm air heater 1 decreases, and the cooling action on the warm air heater 1 main body decreases, so that the warm air heater 1 itself may be overheated.
[0028]
In the present embodiment, a projecting piece 54 is provided at the downstream end 53 of the flow dividing plate 5, and the projecting piece 54 is engaged with a slit-shaped opening 82 provided on the upper surface of the protective cover 8 also serving as a holding member. did. Thus, even if the flow dividing plate 5 is thermally deformed during operation, the downstream end 53 of the flow dividing plate 5 is held, so that the shapes of the combustion gas passage 216 and the air passage 42 are stabilized.
[0029]
Therefore, on the one hand, it is possible to suppress an increase in the generation amount of nitrogen dioxide due to an increase in the generation amount of the nitrogen oxides in the combustion gas due to an increase in the surface temperature of the gas burner. An increase in the amount of nitrogen dioxide generated due to an increase in the rate of conversion of nitrogen monoxide to nitrogen dioxide due to rapid cooling of the combustion gas can be suppressed. Therefore, it is possible to suppress an increase in the emission amount of nitrogen dioxide in the warm air and to secure a stable flow of the warm air from the outlet 11a. In addition, since the decrease in the amount of air flowing through the air passage 42 is suppressed, the warm air heater 1 itself is prevented from being overheated.
[0030]
【The invention's effect】
As described above, in the warm air heater of the present invention, it is difficult to thermally deform the flow dividing plate, and it is possible to suppress an increase in the emission amount of nitrogen dioxide in the warm air exhausted indoors. This has the effect of preventing the appliance itself from being overheated.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating the configuration of a hot air heater according to the present invention. FIG. 2 is an exploded view of a shunt plate. FIG. 3 is a side view of the shunt plate. FIG. Perspective view [Explanation of reference numerals]
REFERENCE SIGNS LIST 1 hot air heater 11 housing 2 combustion housing 3 blower fan 5 distribution plate 54 projecting piece 8 protective cover 82 opening

Claims (3)

In a housing provided with an air outlet and an air inlet, a combustion housing having a gas burner and a blower fan arranged below the combustion housing are provided, and the air sucked into the housing from the air inlet by the operation of the blower fan. A flow dividing plate is provided for partitioning the combustion gas discharged from the combustion cylinder until the combustion gas flows by a predetermined distance, and after exchanging heat with the combustion gas and air through the flow dividing plate, the mixed gas is mixed and warm air is blown into the room from the outlet. Hot air heater that blows
A hot air heater comprising a holding means for holding a part of a downstream end of the distribution plate so that the flow distribution plate is not thermally deformed during operation and the flow of the combustion gas and the air is not obstructed. The holding means is composed of a protrusion provided at a downstream end of the flow dividing plate at a substantially central portion in a width direction of the flow dividing plate, and a holding member having an opening with which the protrusion engages and fixed to the housing. The hot-air heater according to claim 1, characterized in that: 3. The hot air heater according to claim 2, wherein the holding member is a protection cover that covers a flame detection unit that detects presence or absence of a flame of the gas burner or an ignition unit that ignites the gas burner.

Images