JP3531387B2 - Catalytic combustion device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalytic combustion device, which is suitable for use in, for example, a heating device and a drying device.

[0002]

2. Description of the Related Art Heretofore, there has been known a catalytic combustion apparatus which includes a fuel supply means and a combustion air supply means and burns a mixture of fuel and combustion air supplied by these supply means with a catalyst. There is. Since no flame is formed in this catalytic combustion device, no carbon is generated. Further, the catalytic combustion device can significantly suppress the ignition and the emission of exhaust gas at the time of extinguishing, which is seen in flame combustion, and is therefore extremely effective as a heating device for an electric vehicle that requires clean exhaust gas in particular. is there.

By the way, in order to carry out catalytic combustion continuously in the above catalytic combustion apparatus, it is necessary to preheat combustion air at all times to activate the catalyst. The power will increase. In particular, in an electric vehicle, the use of an electric heater, which causes an increase in power consumption, is unsuitable due to the battery capacity limitation. Further, when the combustion air is preheated by the burner, carbon adheres to the catalyst, which causes a decrease in combustion efficiency of the catalyst. Moreover, the catalyst is not sufficiently activated at the time of ignition because it is at a low temperature, which causes a problem that the exhaust emission generated by the burner is discharged as it is.

In order to solve such a problem, Japanese Patent Laid-Open No.
0-30908 discloses a configuration in which exhaust gas circulation pipes are connected in front of and behind the catalytic combustion device, and a part of the exhaust gas is recirculated to the upstream side of the catalytic combustion device to preheat combustion air. There is. In addition, JP-A-4-320710
In the publication, when the raw material gas in which the fuel and air are mixed is fed into the gas passage of the catalyst layer inside the catalytic combustion device, the raw material gas is accelerated through the ejection nozzle, and the depressurizing action is caused by the acceleration. It has been proposed that a part of the exhaust gas is recirculated into the raw material gas to preheat the raw material gas.

According to these conventional devices, the combustion air can be preheated and stable combustion can be performed without using a separately provided heating means such as an electric heater or a burner.

[0006]

However, in the former conventional device, since the exhaust gas circulation pipe is installed outside the combustion device, it is unavoidable to increase the physique, for example, for a vehicle with a large space constraint. As a result, there is a problem that it becomes difficult to mount the heating device. In addition, in the latter conventional device, since it is necessary to mix air and fuel in advance, a device for this mixing is separately required. Furthermore, a large number of gas passages for the catalyst layer are provided, and this gas passage is provided. Correspondingly, since a large number of ejection nozzles are also provided, the number of parts is inevitably increased, the configuration is complicated, and the cost is increased.

The present invention has been made in view of the above points,
An object of the catalyst combustion device is to secure a preheating effect of combustion air by circulating exhaust gas to realize good catalyst combustion, and to reduce the size and simplification of the structure.

[0008]

In order to achieve the above object, the present invention employs the following technical means. Claims 1-2
According to the invention described in 0, the ring-shaped catalyst body (2, 3) for catalytically burning the air-fuel mixture of fuel and combustion air is built in the combustion cylinder (4), and the catalyst body (2, 3) Fuel and combustion air supply means (10, 12, 7) at one end
And a premixing chamber (13) for forming a mixture of fuel and combustion air is provided at a portion on the other end side of the catalyst bodies (2, 3). Further, fuel and combustion air are supplied from one end side of the catalyst bodies (2, 3) toward the premix chamber (13) through the central through holes (2b, 3b) of the catalyst bodies (2, 3). The fuel and the combustion air are mixed in the premix chamber (13). Then, the air-fuel mixture is diverted in the premixing chamber (13) to flow in the catalyst bodies (2, 3) from the other end side toward one end side, and at the one end side of the catalyst bodies (2, 3). Catalyst body (2,
3) Part of the exhaust gas after passing through is recirculated into the combustion air and penetrates the center of the catalyst body (2, 3).
Combustion air and exhaust gas after passing through the catalyst in the holes (2b, 3b)
An exhaust mixing cylinder (5) for mixing with a part of the gas is provided.
The exhaust mixing cylinder (5) is connected to the downstream side.
Pressure rise consisting of a circular pipe with a divergence angle that enlarges the cross-sectional area
It is characterized in that the portion (5b) is formed .

In this way, by recirculating a part of the exhaust gas into the combustion air, the combustion air can be preheated by the heat of the exhaust gas, and this preheating activates the catalyst for catalytic combustion. Can be continuously and stably performed. Moreover, since the mechanism for returning a part of the exhaust gas to the combustion air can be housed inside the combustion cylinder (4), the size of the combustion device can be reduced.

Further, in the present invention, the fuel and the combustion air are
Through hole (2b, at the center of the ring-shaped catalyst body (2, 3))
After passing through 3b), the direction of the U-turn is changed in the premixing chamber (13) so as to flow from the other end side to the one end side of the catalyst bodies (2, 3). -3207
The number of parts can be significantly reduced, the configuration can be extremely simplified, and the cost can be reduced, as compared with the configuration in which a large number of gas passages in the catalyst layer and the ejection nozzles are provided as in the combustion apparatus disclosed in JP-A-10. Can be manufactured.

According to the sixth aspect of the invention, when a liquid fuel is used as the fuel, a fuel absorber (for absorbing and evaporating the supplied liquid fuel) is provided inside the premixing chamber (13). 14), the liquid fuel is temporarily stored in the fuel absorber (14), and the liquid fuel is uniformly evaporated from a large area of the fuel absorber (14) to uniformly mix the fuel and air. A state can be formed and a good combustion state can be realized.

According to the seventh aspect of the invention, the ring-shaped catalyst bodies (2, 3) are divided into a plurality of portions in the axial direction, and the catalyst loading amount in the plurality of catalyst bodies (2, 3) is estimated. Since the number of catalyst bodies (2, 3) is closer to the side of the mixing chamber (13), the closer to the side of the pre-mixing chamber (13) (toward the upstream side), the lower the temperature becomes. The catalyst can be activated, which allows good catalytic combustion from the start. Further, even if the catalyst body on the downstream side has a small amount of catalyst carried, the catalyst body on the upstream side receives the radiation of the catalyst combustion heat on the upstream side and the heat of the exhaust gas reaction at a high temperature, and the temperature rises, so that it can be activated early.

Further, according to the invention as set forth in claim 8, an exhaust gas chamber (9) filled with exhaust gas after passing through the catalyst bodies (2, 3) is formed at one end side of the catalyst bodies (2, 3). However, heat can be exchanged between the exhaust gas in the exhaust gas chamber (9) and the combustion air supplied from the combustion air supply means (7, 8). It becomes possible to preheat with the exhaust gas in (9), and the preheating effect of the combustion air can be further enhanced.

According to the tenth aspect of the present invention, the fuel supply means is provided with the fuel nozzle (10) having a characteristic that the fuel spray angle increases as the liquid fuel flow rate increases, and the liquid fuel flow rate is large. At this time, the fuel spray angle sprayed from the fuel nozzle (10) is increased to increase the fuel nozzle (10).
The fuel sprayed from the through hole (2b, 3) of the catalyst body (2, 3)
It is characterized in that it is directed toward the inner wall surface of b).

As a result, at the time of maximum combustion where the flow rate of liquid fuel is large, the heat transfer from the catalyst bodies (2, 3) at the high temperature portion is utilized to improve the vaporization property of the liquid fuel and achieve good combustion. Can be secured. According to the eleventh aspect of the invention, the flow of the liquid fuel supplied from the fuel supply means (10, 12) is deflected to the inner wall surface of the through holes (2b, 3b) of the catalyst body (2, 3). When the flow rate of the liquid fuel is large, the deflection plate (28) supplies the fuel supplied from the fuel supply means (10, 12) to the through holes (2b, 3b) of the catalyst body (2, 3). ) Is directed toward the inner wall surface.

As a result, as in the tenth aspect, at the time of maximum combustion, the heat transfer from the catalyst bodies (2, 3) at the high temperature portion can be utilized to improve the evaporation property of the liquid fuel. Further, according to the invention of claim 12, a fuel absorber (27) for absorbing and evaporating the supplied liquid fuel on the inner wall surface of the through holes (2b, 3b) of the catalyst bodies (2, 3). It is characterized by having.

As a result, when the vaporization of the liquid fuel is improved by utilizing the heat transfer from the catalyst bodies (2, 3), the fuel absorber (27) is installed to improve the fuel consumption. Can be maintained, and the evaporation can be further improved. Further, according to the invention of claim 13, since the electric heater (15) is arranged in the premixing chamber (13),
The electric heater (15) can preheat the air-fuel mixture at the time of starting combustion, and can perform good catalytic combustion immediately after starting combustion.

According to the fourteenth aspect of the invention, the electric heater (15) is energized at the time of starting the combustion operation, and after a lapse of a predetermined time (t1) from this energization, the supply of the fuel and the combustion air is started in a small amount. Then, the catalyst body (2,
3) When the exhaust gas temperature after passing reaches the first predetermined temperature (T1), the supply amount of fuel and combustion air is continuously or stepwise increased, and then after passing through the catalyst bodies (2, 3). When the exhaust gas temperature of the exhaust gas reaches a second predetermined temperature (T2) higher than the first predetermined temperature (T1), the electric heater (1
Since the power supply to 5) is stopped, the supply amount of fuel and air and the power supply to the electric heater (15) are automatically controlled in association with the exhaust gas temperature during the period from the start to the transition to steady combustion. Thus, the combustion operation can be favorably performed.

According to the fifteenth aspect of the present invention, the auxiliary electric heater (24) for heating the combustion air supplied from the combustion air supply means (7, 8) is provided, and the auxiliary electric heater (24) is provided. Since the auxiliary electric heater (24) is also energized when energized, the preheating effect of the combustion air is further enhanced by the heat generation of the auxiliary electric heater (24) during extremely cold weather, etc., and combustion startability is improved. Can be improved.

According to the sixteenth aspect of the present invention, the starting catalyst body (30) having conductivity is provided at a portion closer to the premixing chamber (13) side than the ring-shaped catalyst body (2).
And the starting catalyst body (30) is configured to be energizable from the outside, and when the starting catalyst body (30) is energized, the starting catalyst body (30) itself generates heat as an electric resistor. The feature is to let.

As a result, the catalyst can be directly heated by the heat generation of the starting catalyst body (30) itself, so that the starting catalyst body (3) is radiated from the electric heater (15). ), The preheating effect of the catalyst can be enhanced and the power consumption can be reduced by improving the preheating effect. Then, as the preheating effect of the starting catalyst body (30) is improved, the startup time of catalytic combustion can be shortened even at low temperature. Moreover, by eliminating the electric heater (15), the size of the entire apparatus can be reduced, and the cost can be reduced by simplifying the structure.

According to the seventeenth aspect of the invention, the conductive starting catalyst body (30) is energized at the time of starting the combustion operation, and after a lapse of a predetermined time (t1) from this energization, the fuel and the combustion air are separated. When the supply is started with a small amount and then the exhaust gas temperature after passing through the ring-shaped catalyst body (2) and the starting catalyst body (30) reaches the first predetermined temperature (T1), the fuel and the combustion air are further supplied. Is continuously or stepwise increased, and then the exhaust gas temperature after passing through both catalyst bodies (2, 30) is further increased to a second predetermined temperature (T2) higher than the first predetermined temperature (T1). At that time, the starting catalyst body (3
It is characterized in that the energization to 0) is stopped, whereby the combustion operation can be satisfactorily automatically controlled as in the fourteenth aspect.

According to the eighteenth aspect of the invention, the ring-shaped catalyst body (2) is electrically conductive and can be energized from the outside, and the starting catalyst body (30) is energized. At times, the ring-shaped catalyst body (2) is also energized,
It is characterized in that both catalyst bodies (2, 30) generate heat as an electric resistance body, so that even when the outside air temperature is extremely low such as −20 ° C. or less, both catalyst bodies (2, 30) are generated. By simultaneously energizing 30), both catalysts of the catalyst bodies (2, 30) can be directly heated by an electric heat generation effect and activated early. Therefore, the combustion rise time can be shortened even at extremely low temperatures, and rapid heating can be achieved.

According to the nineteenth aspect of the present invention, a heating medium for heating and a catalyst body (2, 3, 30) after passing through the catalyst body (2, 3, 30) are provided at one end of the catalyst body (2, 3, 30). Heat exchanger (40) for exchanging heat with exhaust gas to heat a heating medium for heating
Since it has a built-in heat exchanger (40) for heating the heat medium
It is possible to provide a compact catalytic combustion device that also integrates the above.

Further, according to the invention of claim 20, heat exchange between the heat medium for heating and the exhaust gas after passing through the catalyst bodies (2, 3, 30) is performed on the outer peripheral side of the combustion cylinder (4). Then, since the heat exchanger (40) for heating the heating medium for heating is built in, a compact catalytic combustion in which the heat exchanger (40) for heating the heating medium is also integrated in the same manner as in claim 19. A heat exchanger (4) can be provided on the outer peripheral side of the combustion cylinder (4).
0) is arranged, the dimension of the combustion cylinder (4) in the axial direction (height direction) can be shortened, and the mountability on a vehicle or the like can be further improved.

The reference numerals in parentheses of the above means indicate the correspondence with the specific means described in the embodiments to be described later.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 shows a first embodiment of the present invention. The combustion apparatus of this example is applied to a heating device for an electric vehicle. The vertical direction in FIG. 1 is the vertical direction when mounted on a vehicle. Is consistent with Reference numeral 1 denotes a combustion device, which is a cylindrical device having an axis in the vertical direction in FIG. Reference numeral 2 denotes a main catalyst body incorporated in the combustion device 1, which has a ring-shaped (cylindrical) shape with a hollowed central portion. Reference numeral 3 denotes a starting catalyst body, which is arranged adjacent to the lower end surface side of the main catalyst body 2 with a minute gap A therebetween, and has a ring shape like the main catalyst body 2. Reference numerals 2b and 3b are through holes at the center of the ring shape.

For early activation, the starting catalyst body 3 has a smaller size (in other words, heat capacity) than the main catalyst body 2 so that the temperature can be easily raised, and at a low temperature (eg, 2).
Noble metal catalyst (Pt, P
The supported amount (d, etc.) (ratio of the amount of the catalyst to the total weight of the catalyst body) is made larger than that of the main catalyst body 2. In addition, the minute gap A between the main catalyst body 2 and the starting catalyst body 3 is, for example, 5 m.
The size is set to about m. The catalysts of the main catalyst body 2 and the starting catalyst body 3 are carried on honeycomb-shaped carriers 2a, 3a made of ceramic or the like, respectively. The outer peripheral surfaces of the main catalyst body 2 and the starting catalyst body 3 are supported and fixed to the inner wall surface of the combustion cylinder 4. The combustion cylinder 4 defines the main body of the combustion apparatus 1 and is formed of a heat-resistant metal such as stainless steel into a bottomed cylindrical shape. Inside the combustion tube 4, the portion containing the catalyst bodies 2 and 3 constitutes a combustion chamber.

Reference numeral 5 is an exhaust gas mixing cylinder made of a heat-resistant metal such as stainless steel, and its entire shape is formed into a substantially cylindrical shape. The exhaust mixing cylinder 5 is installed in the central through holes 2b, 3b of the main catalyst body 2 and the starting catalyst body 3, and is integrally joined to the inner peripheral surfaces of the two catalyst bodies 2, 3 to be integrated. ing. Here, the exhaust mixing cylinder 5 has a mixing portion 5a formed by a circular pipe portion having an equal cross-sectional area at one end side (inlet side of combustion air and fuel), and has a gentle divergence angle at the other end side. The pressure riser 5b is formed by a circular pipe having (for example, about 5 to 10 °). Further, a tapered enlarged end portion 5c is formed at the inlet side end portion of the mixing portion 5a.

A primary nozzle 6 is arranged in the combustion cylinder 4 adjacent to one end of the main catalyst body 2. The primary nozzle 6 has a narrowed portion 6 on the lower end side that is narrowed in a funnel shape.
It has a and is made of heat-resistant metal. Combustion air and fuel are introduced into the exhaust mixing cylinder 5 from the lower end of the primary nozzle 6. Here, the combustion air is supplied by an air pump (combustion air supply means) 7 and sent from the air inlet 8 to the inner space 60 of the primary nozzle 6.

Further, the throttle portion 6a of the primary nozzle 6 is inserted into the tapered enlarged end portion 5c of the exhaust mixing cylinder 5 by a predetermined amount, and a ring is provided between the tapered enlarged end portion 5c and the throttle portion 6a. The secondary nozzle 6b having a shape is formed. The secondary nozzle 6b is for recirculating the exhaust circulation gas from the exhaust gas chamber 9 formed on the outer peripheral side of the primary nozzle 6 into the exhaust mixing cylinder 5.

The inner space 60 of the primary nozzle 6 is partitioned from the exhaust gas chamber 9 at a portion other than the small diameter opening at the tip of the throttle portion 6a. In other words, the primary nozzle 6 also functions as a partition member that partitions the inner space (fuel and air supply side space) 60 and the exhaust gas chamber 9.
A fuel nozzle 10 sprays the liquid fuel (for example, kerosene) sent from the fuel tank 11 by the fuel pump 12 toward the center of the inner space 60 of the primary nozzle 6. That is, in the inner space 60 of the primary nozzle 6, the air pump 7
The air inlet 8 and the fuel nozzle 10 are open. Here, in this example, the fuel nozzle 10 and the fuel pump 12 constitute a fuel supply means.

Reference numeral 13 denotes a premixing chamber for mixing the liquid fuel and the combustion air, and is arranged inside the combustion cylinder 4 at the other end side (lower end side) of the main catalyst body 2 and the starting catalyst body 3. . 14
Is a metal mesh-shaped fuel absorber made of heat-resistant metal, and is arranged over a wide area from the inner surface to the side surface of the bottom wall of the premix chamber 13. Here, as the fuel absorber 14,
In addition to the wire mesh member (wick), a foam metal member, a thin plate-shaped porous ceramic member, or the like can be used.

The bottom wall of the premixing chamber 13 facing the lower surface of the starting catalyst body 3 smoothly changes the direction of the flow of the mixture of fuel and air from the center to the radially outward side. Therefore, the central portion has a mountain-like protruding shape. 1
3a is the protrusion. Reference numeral 15 denotes an electrothermal heater disposed in the premix chamber 13, which is, for example, a sheath heater bent in a spiral shape, and is for heating the starting catalyst body 3 and the fuel absorber 14 at the time of starting. 15a, 15b
Is a terminal portion for connecting the electric heater 15 to an external circuit.

Reference numeral 16 is an exhaust gas outlet for discharging the exhaust gas from the exhaust gas chamber 9 to the outside. Reference numeral 17 denotes a temperature detector (thermistor) arranged near the exhaust gas outlet 16 in the exhaust gas chamber 9. Reference numeral 18 denotes a heat insulating material provided over the entire outer periphery of the combustion cylinder 4, and a cover 19 is installed with the heat insulating material 18 interposed therebetween. 20 is a combustion cylinder 4 and a cover 19
Is an upper end plate that closes the upper end opening of the
A fuel nozzle 10 and an air inlet 8 are attached to.

The exhaust gas discharged from the exhaust gas outlet 16 is sent to a heat exchanger (not shown), where heat is exchanged between the exhaust gas and water (heating medium for heating) to heat the water. The heated hot water is sent to the heater core of the air conditioner by a pump, and the heater core heats the conditioned air to heat the passenger compartment. FIG. 2 is an electric control block diagram of the first embodiment, in which 21 is a control device for controlling the electric devices (7, 12, 15) in the combustion procedure, and 22 is an operation switch of the combustion device 1.

Next, the operation of the above structure will be described.
Now, when the operation switch 22 is turned on, the control device 21 first energizes the electric heater 15 so that the electric heater 15
Preheating of the starting catalyst 3 and the fuel absorber 14 is carried out by the heat generation of. A predetermined time t1 from turning on of the operation switch 22 (see FIG.
(See), the timer means in the control device 21 energizes the air pump 7 and the fuel pump 12, so that the supply of combustion air and fuel is started.

Here, the supply amounts of combustion air and fuel are
Initially, the control device 21 sets the rotational speeds of both pumps 7 and 12 to a low rotational speed to make a minute amount (for example, about 1/10 of the maximum combustion amount). The reason for this is that if a large amount of combustion air is made to flow from the beginning, the starting catalyst 3 and the fuel absorber 14 may be cooled and the catalytic reaction may not occur.

The liquid fuel is sprayed from the fuel nozzle 10 toward the center of the inner space 60 of the primary nozzle 6, and the combustion air is supplied from the air inlet 8 to the inner space 60 of the primary nozzle 6.
Sent in. Then, the liquid fuel sprayed from the nozzle 10 is jetted downward in the exhaust mixing cylinder 5, and the premixing chamber 13
It vaporizes on the fuel absorber 14 therein and is mixed with combustion air. This mixture changes direction (U-turn) in the premix chamber 13.
Then, it flows into the starting catalyst body 3 from below to above, reacts and burns in the starting catalyst body 3.

The main catalyst body 2 emits radiation from the starting catalyst body 3,
And is gradually heated by the high temperature reaction gas. Then, after starting the supply of fuel and air, a predetermined time t shown in FIG.
When 2 has elapsed or the temperature detected by the temperature detector 17 provided in the exhaust gas chamber 9 reaches the first predetermined temperature T1 (for example, in the case of kerosene fuel, about 300 ° C.), the control device 2
The rotation speed of both pumps 7 and 12 is gradually increased by 1 to gradually increase the combustion amount. The combustion gas that has risen in the starting catalyst body 3 and the main catalyst body 2 flows into the exhaust gas chamber 9 and is then discharged to the outside from the exhaust gas outlet 16.

The temperature detected by the temperature detector 17 is the second
Predetermined temperature T2 (for example, about 500 ° C for kerosene fuel)
When it reaches, it is determined that the main catalyst 2 has been activated, and the controller 21 stops energizing the electric heater 15, and thereafter, the steady combustion is started. Instead of determining that the temperature detected by the temperature detector 17> the predetermined temperature T2, a predetermined time t3 shown in FIG. 3 is set by a timer means, and when the predetermined time t3 elapses, energization of the electric heater 15 is stopped. You may.

By the way, during the steady combustion, the combustion air is accelerated from the throttle portion 6a of the primary nozzle 6 to the mixing portion 5a having an equal cross-sectional area of the exhaust mixing cylinder 5, and is jetted out. Due to the ejector effect of the flow, the pressure in the vicinity of the secondary nozzle 6b is reduced, and a part of the exhaust gas in the exhaust gas chamber 9 is recirculated into the exhaust mixing cylinder 5 through the secondary nozzle 6b. Here, since the exhaust mixing cylinder 5 is provided with the pressure increasing portion 5b formed of a circular pipe having a gentle divergence angle on the downstream side of the mixing portion 5a, the combustion air and the fuel are passed while passing through the pressure increasing portion 5b. The air-fuel mixture converts the velocity component into pressure and recovers the pressure.

As described above, in the device of this embodiment, by recirculating a part of the exhaust gas in the exhaust gas chamber 9 into the combustion air, the combustion air can be preheated by the high temperature exhaust gas heat. Since the catalyst bodies 2 and 3 can be maintained in the activated state, the catalytic combustion can be favorably continued. Further, the primary nozzle 6 to which the combustion air is supplied is arranged at the center of the exhaust gas chamber 9, and the combustion air and the exhaust gas flow as counterflows inside and outside the primary nozzle 6. Therefore, the combustion air can be preheated by the exhaust gas by heat conduction through the metal primary nozzle (partitioning member) 6, and the preheating effect of the combustion air can be further enhanced.

When the combustion is stopped, the operation switch 22 is turned off. By turning off this switch 22,
The control device 21 immediately stops the fuel pump 12, but the air pump 7 continues to operate for a predetermined time t4, burns the residual fuel in the combustion cylinder 4, and then cools the inside of the combustion cylinder 4 (post-purge). operation). Then, the predetermined time t4
After a lapse of time, the air pump 7 is also stopped and all the devices are stopped.

Summarizing the features of the first embodiment described above, the fuel is supplied with the catalyst bodies 2 and 3 activated.
Since the engine is stopped, exhaust emissions are hardly emitted even during ignition and extinction, and clean combustion can be performed. Further, at the time of starting, the preheating of the fuel and the catalyst is performed by the premix chamber 1.
Efficiently performed with one electric heater 15 provided in No. 3, and exhaust gas recirculation is used for preheating combustion air during steady combustion, so an electric heater is not required and efficient combustion is possible with low power consumption. Becomes (Second Embodiment) FIG. 4 shows a second embodiment according to the present invention. In the first embodiment, on one end side of the catalyst bodies 2 and 3, a primary nozzle 6 for ejecting combustion air is arranged in the center of the combustion cylinder 4, and exhaust gas is provided on the outer peripheral side of the primary nozzle 6 by an ejector effect. Although the secondary nozzle 6b that recirculates is formed, in the second embodiment, the primary nozzle 6 and the secondary nozzle 6b are arranged in reverse, that is, the secondary nozzle 6b.
Is arranged on the center side, and the primary nozzle 6 is arranged on the outer peripheral side in a ring shape.

More specifically, in the second embodiment,
A combustion air chamber 23 that is partitioned from the exhaust gas chamber 9 is formed, and an air inlet 8 is connected to this combustion air chamber 23 to introduce combustion air. This introduced air is
The ring-shaped primary nozzle 6 ejects into the exhaust mixing cylinder 5. On the other hand, the secondary nozzle 6b is the primary nozzle 6
Is formed in the center of the secondary nozzle 6b, and only the liquid fuel is sprayed from the fuel nozzle 10 to the inside of the secondary nozzle 6b, and combustion air is not supplied. In addition, the inner space of the secondary nozzle 6b is entirely open to the exhaust gas chamber 9 in the upper part thereof.

Therefore, by ejecting the combustion air from the primary nozzle 6, the tip of the secondary nozzle 6b is decompressed by the ejector effect, and a part of the exhaust gas in the exhaust gas chamber 9 passes through the secondary nozzle 6b. And is recirculated into the exhaust mixing cylinder 5. According to the configuration of the second embodiment, by the time the combustion air supplied from the air inlet 8 enters the exhaust mixing cylinder 5, the exhaust gas flowing around the inner and outer peripheries of the combustion air chamber 23 has a wider heat exchange (heat The air for combustion can be preheated by the area of conduction. Therefore, it is possible to efficiently preheat the combustion air. Other than that, the same effects as in the first embodiment can be obtained. (Third Embodiment) FIG. 5 shows a third embodiment, which is intended to improve the combustion startability at low temperature as compared with the first embodiment. For this reason, as shown in FIG.
The auxiliary electric heater 24 including a C heater is attached to the primary nozzle 6
The inner space 60 is arranged in a spiral shape. As a result, when the electric heater 15 is energized and the auxiliary electric heater 24 is energized at the same time when the engine is started at a low temperature in an extremely cold region, the preheating effect of the combustion air can be improved and the combustion startability can be improved. (Fourth Embodiment) FIG. 6 shows a fourth embodiment. In each of the above-described first to third embodiments, the catalyst body 2, 3 is used.
The above catalyst is carried on the honeycomb-shaped carriers 2a, 3a, but in the fourth embodiment, a large number of granular catalyst bodies 2,
3 is arranged in a hollow double cylindrical body 25, and the granular catalyst bodies 2, 3 are held in the double cylindrical body 25 by a wire mesh support member 26. The present invention can be implemented with such a configuration. (Fifth Embodiment) In all of the above-described first to fourth embodiments, since all the liquid fuel is sprayed from the fuel nozzle 10 toward the fuel absorber 14 in the premix chamber 13, the fuel evaporation Is performed by the fuel absorber 14, but when the combustion amount (fuel flow rate) is increased by shifting to the steady combustion, it is necessary to evaporate all the increased fuel in the fuel absorber 14. There is a case where the capacity is insufficient and the evaporation of fuel deteriorates.

Therefore, in view of the above points, in the fifth embodiment, even at the maximum combustion amount, the heat of the high temperature portion inside the combustion device is effectively utilized to improve the vaporization property of the liquid fuel. . That is, FIGS. 7 to 9 show the fifth embodiment, and the swirl type fuel nozzle shown in FIG. 8 is particularly used as the fuel nozzle 10. As shown in FIG. 8, this swirl type fuel nozzle 10 has a pipe-shaped housing 10a made of a heat-resistant metal such as stainless steel, and has a spray hole 10 formed at the tip end thereof in a shape that expands in a divergent manner.
b is open.

Inside the front end of the housing 10a, two plate-like members 10c and 10d, that is, a first plate and a second plate, are arranged in an overlapping manner from the upstream side to the downstream side of the fuel flow. It is fixed to the wall. A circular swirl chamber 10e is formed between the plate-shaped members 10c and 10d. First plate member 10 located on the upstream side
c is two parallel flat side portions 1 as shown in FIG. 8 (b).
0f is formed into a planar shape, whereby a space into which fuel can flow is formed between the flat side surface portion 10f and the inner wall surface of the housing 10a, and further, the first plate-shaped member 10
Two fuel introduction holes 10g, which communicate between the flat side surface portion 10f and the circular swirl chamber 10e, are provided at c at 180 ° symmetrical positions.

Circular swirl chamber 10e of this fuel introduction hole 10g
By making the opening direction with respect to the tangential direction of the swirl chamber 10e, the fuel from the flat side surface portion 10f is circularly swirl chamber 1e.
0e is introduced tangentially to form a swirling flow of fuel. On the other hand, the second plate-shaped member 10d has a tapered surface 10h that gradually reduces the cross-sectional area of the circular swirl chamber 10e, and a narrowed hole 10i is provided at the tip of this tapered surface 10h. The plate members 10c and 10d are preferably formed by free-cutting brass having excellent machinability.

In the swirl type fuel nozzle 10 having such a structure, since the swirling force of the fuel in the circular swirl chamber 10e depends on the fuel flow rate, as shown in FIG. 9, the fuel spray angle increases as the fuel flow rate increases. It has the property of increasing. On the other hand, a fuel absorber 27 is arranged and joined to the inner peripheral surface of the exhaust mixing cylinder 5 from the middle of the mixing portion 5a of the exhaust mixing cylinder 5 to the entire length of the pressure rising portion 5b. Here, the fuel absorber 27 is the fuel absorber 1 in the premix chamber 13.
As in the case of 4, the wire mesh member made of a heat-resistant metal can be used.

According to the fifth embodiment, when the combustion amount (fuel flow rate) is small, such as when starting combustion, the swirl force of the fuel is small in the swirl type fuel nozzle 10, so the fuel spray angle is about 10 °. Will be a small value of. Therefore, the fuel sprayed from the fuel nozzle 10 does not adsorb to the fuel absorber 27 of the exhaust mixing cylinder 5 as shown by the two-dot chain line B in FIG. The fuel reaches the fuel absorber 14 in the chamber 13, receives heat from the electric heater 15 in the fuel absorber 14, and evaporates.

At this time, since the fuel flow rate is small, the fuel can be satisfactorily evaporated only by the fuel absorber 14. On the other hand, if the amount of combustion (fuel flow rate) increases after shifting to steady combustion,
In the swirl type fuel nozzle 10, since the swirling force of the fuel increases, the fuel spray angle increases, and the fuel spray angle increases to about 40 ° at the time of maximum combustion.

As the fuel spray angle from the fuel nozzle 10 increases in this way, part of the fuel sprayed from the fuel nozzle 10 contacts the fuel absorber 27 in the exhaust mixing cylinder 5 (see FIG. 7). Adhesive chain line C) is adsorbed. Here, since the fuel absorber 27 is heated by the heat transfer from the catalyst bodies 2 and 3 in the high temperature part through the metal wall surface of the exhaust mixing cylinder 5,
The fuel evaporates favorably in the fuel absorber 27.

That is, compared with the case where the fuel is adsorbed only to the fuel absorber 14 in the premix chamber 13 as in the first to fourth embodiments, according to the fifth embodiment, the atomized fuel is used as the fuel absorber. 14 and the fuel absorber 27, and
Since the fuel absorber 27 can be heated to a high temperature by the heat transfer from the catalyst bodies 2 and 3, the fuel can be satisfactorily evaporated even at the time of maximum combustion, so that a good combustion state can be obtained from the time of starting to the time of maximum combustion. Can be maintained. (Sixth Embodiment) FIG. 10 shows a sixth embodiment, which is a modification of the fifth embodiment. That is, in the fifth embodiment, the swirl type fuel nozzle 10 having the characteristic that the fuel spray angle increases as the fuel flow rate increases is used. However, in the sixth embodiment, the swirl type fuel nozzle 10 is abolished and the first embodiment is used. ~ The same fuel nozzle 10 as in the fourth embodiment is used. That is, when the fuel supply pressure from the fuel pump 9 becomes equal to or higher than a predetermined pressure, the fuel nozzle 10 of the type that opens the valve and sprays the fuel is used. In this type of fuel nozzle 10, the fuel spray angle is substantially constant regardless of the increase / decrease in the fuel flow rate.

Therefore, in the sixth embodiment, the exhaust mixing cylinder 5
A fuel absorber 27 is provided inside, and a deflecting plate 28 for deflecting the flow of fuel is additionally installed. This deflector 28
Is made of a heat-resistant metal such as stainless steel.
As shown in the top view of (b), it has a circular ring portion 28a having an outer diameter equivalent to the inner diameter of the exhaust mixing cylinder 5, and a plurality of arm portions 28b are provided radially inside the circular ring portion 28a. A conical portion 28c is formed at the center of the radial arm portion 28b. The top of the conical portion 28c is arranged in the exhaust mixing cylinder 5 so as to face the fuel upstream side. Further, in the example of FIG. 10, the deflection plate 28 is arranged in the exhaust mixing cylinder 5 near the upstream end of the pressure rising portion 5b, and the deflection plate 28 is joined to the inner wall surface of the exhaust mixing cylinder 5.

According to the sixth embodiment, the fuel sprayed from the fuel nozzle 10 into the exhaust mixing cylinder 5 contacts the deflection plate 28. At this time, when the fuel flow rate is small, such as at the time of starting, the fuel spray speed is slow, so most of the fuel that has contacted and adhered to the deflection plate 28 hangs downward due to gravity. Therefore, most of the fuel sprayed from the fuel nozzle 10 reaches the fuel absorber 14 in the premix chamber 13 and is evaporated there.

When the fuel flow rate is large, such as at the time of maximum combustion, the fuel spray rate is high, so the fuel nozzle 10
A part of the fuel sprayed from the engine collides with the deflecting plate 28 and bounces back, and thereafter, the fuel that collides is adsorbed by the fuel absorber 27 in the exhaust mixing cylinder 5 and evaporates there. Therefore, when the fuel flow rate is large, the atomized fuel can be dispersed and evaporated in both the fuel absorber 14 and the fuel absorber 27, so that the fuel can be favorably vaporized even at the time of maximum combustion, and good combustion can be achieved. The state can be maintained. (Seventh Embodiment) FIG. 11 shows a seventh embodiment in which the exhaust mixing cylinder 5 in the fifth embodiment is omitted. That is, in the seventh embodiment, the exhaust mixing cylinder 5 is eliminated,
The exhaust gas is mixed into the combustion air through the through holes 2b and 3b of the catalyst bodies 2 and 3.

In this case, the efficiency of recirculating the exhaust gas into the combustion air is reduced, but instead, the exhaust mixing cylinder 5 is replaced.
By eliminating the above, the structure can be simplified, and at the same time, the fuel can be directly sprayed on the inner wall surfaces of the catalyst bodies 2 and 3 which have become high in temperature by the combustion, so that the fuel vaporization property can be improved. In this case, if the fuel absorber 27 is installed on the inner wall surface of the main catalyst body 2, the fuel retaining property on the inner wall surface of the main catalyst body 2 is improved, and the evaporation of the fuel can be further improved.

Incidentally, as in the fifth embodiment, the first to fourth
Needless to say, the exhaust mixing cylinder 5 can be omitted in the embodiment and the sixth embodiment. (Eighth Embodiment) In the above-described first to seventh embodiments, the electric heater 15 is installed in the premix chamber 13, and the starting catalyst body 3 having a small heat capacity is provided so as to face the premix chamber 13. By installing and preheating the starting catalyst body 3 with the radiant heat from the electric heater 15, the startability of catalytic combustion at low temperature is improved. However, in the eighth embodiment,
As shown in FIG. 12, instead of the electric heater 15 and the starting catalyst body 3, a conductive starting catalyst body 30 is used.

In FIG. 12, the conductive starting catalyst body 3 is used.
0 is installed between the main catalyst body 2 and the premix chamber 13 with a minute gap A interposed between the main catalyst body 2 and the main catalyst body 2. As shown in FIG. 13B, the starting catalyst body 30 is a thin metal plate,
For example, stainless steel (SUS430, plate thickness 0.05m
A carrier 30a is formed by stacking a flat plate 30b made of m) and a corrugated plate 30c on top of each other, and a catalyst is supported on the carrier 30a, and then the carrier is wound many times to form a honeycomb disk shape as a whole. is doing.

The catalyst supported on the carrier 30a is, for example, Pt, and the supported amount (the ratio of the catalyst amount to the total weight of the catalyst body) may be about 0.5 wt%. Then, as shown in FIG. 13 (a), the positive electrode side electrode terminal 30d is arranged at the center of the starting catalyst body 30, and the negative electrode side electrode terminal 30e is arranged at the outer peripheral portion. The starting catalyst body 30 is energized by applying a power supply voltage between the terminals 30d and 30e. 8th
In the embodiment, the lower ends of the exhaust mixing cylinder 5 and the fuel absorber 27 are extended until they come into contact with the upper surface portion of the starting catalyst body 30, so that the mixture of fuel and air passing through the exhaust mixing cylinder 5 is inevitable. It passes through the starting catalyst body 30.

In the eighth embodiment, the size ratio of the main catalyst body 2 to the starting catalyst body 30 is 5: 1, and the minute gap A is about 5 mm. Other points are the same as in the first to seventh embodiments. The operation of the eighth embodiment will be described. Now, when the operation switch 22 shown in FIG. 2 is turned on, electric power is supplied to the conductive starting catalyst body 30 from the power source (not shown) through both electrode terminals 30d and 30e. here,
The power consumption of the starting catalyst body 30 is, for example, 300 to 40.
It is about 0W. By this energization, the starting catalyst body 30 acts as an electrothermal heating element due to its own electrical resistance, and the catalyst carried on the carrier 30a can be directly and rapidly heated.

At the same time, the main catalyst body 2 and the fuel absorber 14 can be preheated by the radiant heat from the starting catalyst body 3. Then, after the operation switch 22 is turned on, FIG.
When a predetermined time t1 shown in 4 has elapsed, the air pump 7 and the fuel pump 12 are started to start the supply of combustion air and fuel. The supply amount of combustion air and fuel is
Initially, it is a small amount, and is gradually increased stepwise as time t2, t3, and t3 'elapse. When the temperature detected by the temperature detector 17 reaches the predetermined temperature T2, it is determined that the catalyst has reached the activated state, and the energization to the starting catalyst body 30 is cut off.

According to the eighth embodiment, the starting catalyst body 30 is used.
Since the metallic catalyst carrier 30a of the above acts as an electric heating element due to its own electric resistance and can directly heat the catalyst carried on the carrier 30a, the electric heater 15 in the first to seventh embodiments can As compared with the case where the starting catalyst body 3 is preheated by radiant heat, the preheating effect of the catalyst can be enhanced, and the improvement of the preheating effect can reduce power consumption.

As the preheating effect of the starting catalyst body 30 is improved, the preheating effect of the main catalyst body 2 and the fuel absorber 14 can be improved, so that the catalyst early activation and the fuel absorber 14 can be performed even at a low temperature. Combustion start-up time can be shortened in combination with the promotion of fuel vaporization. Moreover, by eliminating the electric heater 15, the size of the entire apparatus can be reduced, and
Cost can be reduced by simplifying the structure.

The catalyst carrier 30a of the starting catalyst body 30
In addition to a heat-resistant metal such as stainless steel, it may be formed of a ceramic containing conductive silicon carbide as a main component. Further, although the starting catalyst body 30 is formed in a disc shape, it may be formed in a ring shape having a central hole portion having the same inner diameter as the main catalyst body 2. In the case of this ring shape, as compared with the disk shape, the fuel passes through the center hole of the starting catalyst body 30 and reaches the fuel absorber 14, so the fuel by the starting catalyst body 30 at the time of combustion start. The heating effect is reduced and the fuel vaporization is deteriorated. However, instead, the presence of the central hole of the starting catalyst body 30 can reduce the pressure loss of the mixture of fuel and air, so that the flow rate of the recirculated exhaust gas can be increased. Therefore, in the case of a highly evaporative fuel such as gasoline as the fuel, the effect of preheating combustion air by the recirculated exhaust gas can be enhanced and the effect of early activation of the catalyst can be enhanced, which is advantageous.

Also in the eighth embodiment, the swirl type fuel nozzle 10 shown in FIG. 8 is used, the exhaust mixing cylinder 5 is eliminated, and the main catalyst body 2 which has a high temperature during steady combustion is used. Needless to say, the fuel may be directly sprayed on the inner wall surface. (Ninth Embodiment) FIG. 15 is a ninth embodiment, in which a plurality of, for example, three blocks 201 are provided in the main catalyst body 2 in the eighth embodiment in the flow direction of combustion air (the vertical direction in the drawing). It is divided into 202 and 203. Then, the upstream side of the flow of the combustion air (in FIG. 15, the premix chamber 13
The activation temperature of the catalyst is set to be lower toward the side portion), that is, from the block 203 to the block 201.

For this reason, in this example, the amount of catalyst supported (the ratio of the amount of catalyst to the total weight of the catalyst) is increased from the block 203 to the block 201. Specifically, the supported amount of the catalyst is set to block 203: 0.5 wt%,
Block 202: 1.0 wt%, block 201: 1.
It is set to 5 wt%. Accordingly, the block 201 located on the upstream side of the flow of the combustion air can be activated even at a lower temperature. According to a preliminary test by the present inventors using propylene gas, the catalyst activation temperature is 180 ° C. when Pt is 1.5 wt%, and Pt:
200 ° C at 1.0 wt%, Pt: 0.5 wt%
In the case of, it is 250 ° C.

Therefore, in the upstream block 201 of the main catalyst body 2, the catalyst can be activated immediately after the start of energization of the starting catalyst body 30, and the fuel flow rate can be increased correspondingly in an early manner. The activation area of the catalyst body 2 can be rapidly expanded. As a result, in the ninth embodiment, it is possible to shift to the maximum combustion amount earlier than in the case where the amount of catalyst carried in the main catalyst body 2 is kept constant at, for example, 0.5 wt%. Therefore, the heating effect of the room can be rapidly raised.

Compared to the case where the amount of catalyst supported on the main catalyst body 2 is constant at, for example, 1.5 wt%, the amount of expensive catalyst can be reduced with almost no change in the transition time to the maximum combustion amount. It is possible to reduce the cost. Further, the main catalyst body 2 is provided in a plurality of blocks 201 to 20.
Dividing into three to increase the amount of catalyst carried toward the upstream side is effective not only at the time of heating start-up but also in steady combustion. That is, the combustion device of the present invention is not always used at the maximum combustion amount, but it is desirable that it can be used in a wide combustion range, depending on the purpose of use, environment of use, and the like. In catalytic combustion, the combustion temperature generally decreases as the combustion becomes smaller, and the reaction is completed upstream of the catalyst.

Therefore, by making the catalyst block 201 on the upstream side active at a low temperature, it becomes possible to carry out catalytic combustion to a smaller combustion region. As a means for lowering the activation temperature of the catalyst body, in addition to increasing the amount of catalyst supported, the contact is increased as it goes to the upstream side of the flow of combustion air (the portion on the premixing chamber 13 side in FIG. 1). The physique of the medium may be reduced,
In addition, increasing the amount of catalyst supported may be combined with decreasing the size of the catalyst body.

Further, the material itself of the catalyst is changed (for example,
Rh may be added) and the activation temperature may be lowered toward the upstream side of the flow of the combustion air. Further, although the main catalyst body 2 is divided into three blocks 201 to 203 in this example, the number of divisions is not limited to three, and may be changed as appropriate according to the target combustion start-up time, manufacturing cost, and the like. Of course you can.

Further, the main catalyst body 2 is divided into a plurality of blocks 201.
It is also possible to increase the amount of supported catalyst toward the upstream side with one main catalyst body 2 as it is without dividing into ~ 203. (Tenth Embodiment) FIG. 16 is a tenth embodiment, in which the main catalyst body 2 in the eighth embodiment is divided into two, and the catalyst bodies divided into these two are all conductive catalyst bodies 204,
205, and a small gap B between the two 204, 205
(About 5 mm) is provided. The conductive catalyst bodies 204, 205 have a catalyst carrier 204a, 205a with an eighth
Conductivity is imparted by the same structure as the starting catalyst body 30 in the embodiment.

In this example, both conductive catalyst bodies 204, 2
Reference numeral 05 indicates electrode terminals 204a,
05a and the negative electrode terminals 204b and 205b on the outer periphery of the starting catalyst body 30.
And both conductive catalyst bodies 204 and 205 are electrically connected in parallel with each other. Outside air temperature is -20 ° C
In the following extremely low temperatures, it is difficult to activate the catalyst early though rapid heating is required.
According to the embodiment, by simultaneously energizing the three catalysts of the starting catalyst body 30 and the both conductive catalyst bodies 204 and 205, the catalysts of the three catalysts are supported on the carriers 204a, 205a and 30.
It can be activated early by directly heating it by the electric heating effect of a. Therefore, the combustion rise time can be shortened even at extremely low temperatures.

On the other hand, when the outside air temperature is relatively high (for example,
In the case of 10 ° C. or higher), only the starting catalyst body 30 is energized and both conductive catalyst bodies 204 and 205 are de-energized, so that the catalyst efficiency can be improved according to the situation such as the outside temperature. Preheating can be done. However, even when the outside air temperature is relatively high, it is possible to energize all of the above three members to achieve early rise of combustion.

In the tenth embodiment, the main catalyst body 2 is not divided into a plurality of pieces, and one main catalyst body 2 is left as it is, and only a part of the main catalyst body 2 on the upstream side of the combustion air is electrically conductive. It may be used as a catalytic body. Further, as in the ninth embodiment, the number of divisions and the physique of the main catalyst body 2 can be variously changed. Also,
The amount of catalyst supported on both conductive catalyst bodies 204 and 205 is
The amount of catalyst supported on the upstream conductive catalyst body 204 is large,
The amount of catalyst supported on the conductive catalyst body 205 on the downstream side may be small. (Eleventh Embodiment) FIG. 17 shows an eleventh embodiment. In the first embodiment of FIG. 1, heat for exchanging heat between high-temperature exhaust gas (combustion gas) and a heat medium (for example, water). The exchanger is compact and integrated inside the catalytic combustion device.

In FIG. 17, a heat exchanger 40 for exchanging heat between the high-temperature exhaust gas and the heat medium comprises a combustion cylinder 4 and an upper end plate 2.
It is arranged at a portion between 0 and 0 and on the outer peripheral side of the supply paths of combustion air and fuel. The heat exchanger 40 has a cylindrical outer cylinder 41, an inner cylinder 42, and a coil 43. A cylindrical space between the outer cylinder 41 and the inner cylinder 42 is defined by a spiral partition plate 45 into a spiral passage 44.

A heat medium inlet pipe 46 is arranged at one end of the spiral passage 44 and fixed to the outer cylinder 41. Further, a heat medium outlet pipe 47 is arranged at the other end of the spiral passage 44 (a symmetrical position of 180 ° in the circumferential direction of the outer cylinder 41) and is fixed to the outer cylinder 41. Also, the coil 4
3 is a hollow pipe bent in a spiral shape, and the inlet portion 43a of the coil 43 is joined immediately after the installation portion of the inlet pipe 46 in the spiral passage 44, and the heat medium from the inlet pipe 46 is joined. Flows into the passage 44 and at the same time the coil 43
It is designed to flow into the inlet portion 43a of the.

The outlet portion 43b of the coil 43 is joined to a portion of the spiral passage 44 adjacent to the outlet pipe 47, and the heat medium flowing out from the outlet portion 43b is passed through the passage 4.
After merging with the heat medium in No. 4, it flows to the outlet pipe 47 side. That is, the heat medium flows in parallel in the coil 43 and the spiral passage 44. Also, the inner cylinder 42
The plate-shaped fins 48 are arranged on the inner peripheral side of the
About 4.5 mm), a large number of them are arranged radially,
It is integrally joined to the inner peripheral wall of the inner cylinder 42.

Each member 41 to 4 of the above heat exchanger 40
It is preferable that all of 3, 45 to 48 are made of aluminum from the viewpoint of thermal conductivity, and the respective joints are joined by brazing, for example. Further, as the heat medium, an antifreeze liquid whose freezing temperature is lowered to about −30 ° C. is used in this example, but water or air may be used as the heat medium depending on the usage of the combustion device. .

The heat medium flowing out from the outlet pipe 47 is pressure-fed by a hot water pump (not shown) to a heater core (heating heat exchanger) installed in the air passage of the vehicle heating system, and the heater core blows air. The generated air and the heat medium are exchanged with each other to heat the blown air, and the heated hot air is blown into the passenger compartment. The outlet pipe 47 is provided with a heat medium temperature detector 49 for detecting the temperature of the heat medium.

On the other hand, in this example, the heat exchanger 4 described above is used.
With the installation of 0, the intake cylinder 50 is integrally formed in the central portion of the upper end plate 20, and the intake cylinder 50 is arranged so as to extend inside the central portion of the coil 43. One end of the intake cylinder 50 (upper end in FIG. 17) is closed by a lid 51, and
The air inlet 8 is arranged in the lid 51, and the combustion air from the air inlet 8 is introduced into the intake cylinder 50.

On the other end (lower end in FIG. 17) of the intake cylinder 50, there is provided a straightening plate 52 in which many small holes are evenly formed.
In addition to rectifying the combustion air, the fuel nozzle 10 is attached to the center of the rectifying plate 52. In addition, the intake cylinder 50
A primary nozzle 6 is attached to the other end of the. A fuel pipe 53 formed on a lid 51 is connected to the fuel nozzle 10, and fuel from the fuel pump 12 is supplied through the fuel pipe 53.

The operation of the eleventh embodiment will be described. From the inlet pipe 46 to the spiral passage 44 of the heat exchanger 40.
A part of the heat medium (antifreeze liquid) that has flowed in flows inside the coil 43, and the remaining heat medium (antifreeze liquid) flows inside the spiral passage 44. During this time, the heat medium exchanges heat with the exhaust gas (combustion gas) via the fins 48 and the coil 4
Heat is directly exchanged with exhaust gas (combustion gas) on the outer surface of No. 3 and heated to a high temperature. Then, the two heat medium flows merge on the upstream side of the outlet pipe 47 and flow out from the outlet pipe 47 to the outside.

The heating capacity is controlled, for example, by increasing or decreasing the combustion amount according to the temperature detected by the heat medium temperature detector 49. With the above configuration and operation, the heat exchanger 40 having a compact configuration and high efficiency can be integrated with the catalytic combustion device. Further, in flame combustion, generally, carbon generated during combustion adheres to the gaps between the fins 48 and fills the gaps between the fins 48, which tends to cause a decrease in heat exchange efficiency. In catalytic combustion according to the invention,
Since almost no carbon is generated, the distance between the fins 48 can be set to a small value of about 4.5 mm as described above, and the heat exchange efficiency can be improved.

The points other than the above are the same as those in the first embodiment. (Twelfth Embodiment) FIG. 18 shows a twelfth embodiment, which is obtained by removing the coil 43 from the eleventh embodiment of FIG. This reduces the heat exchange efficiency between the heat medium and the exhaust gas, but has the advantage of simplifying the configuration of the heat exchanger 40. (Thirteenth Embodiment) FIG. 19 shows the thirteenth embodiment. In the eleventh and twelfth embodiments of FIGS. 17 and 18, a heat exchanger 40 for exchanging heat between the high temperature exhaust gas and the heat medium.
Is arranged between the combustion cylinder 4 and the upper end plate 20, but the heat exchanger 40 is arranged on the outer peripheral side of the catalyst bodies 2 and 3 in the thirteenth embodiment.

That is, in the thirteenth embodiment, the heat exchanger 4
0 is arranged on the outer peripheral side of the catalyst bodies 2 and 3, radial fins 48 are arranged on the outer peripheral side of the combustion cylinder 4 with a minute gap, and an inner cylinder arranged on the outer peripheral side of the radial fin 48. A spiral partition plate 45 forms a spiral passage 44 between the outer cylinder 42 and the outer cylinder 41. Therefore, the outer cylinder 4
1 also serves as the cover 19 in the first to twelfth embodiments.

Further, a bottom plate 42a of the inner cylinder 42 is arranged outside the premix chamber 13 (lower side in FIG. 19) at a predetermined interval, and the exhaust gas outlet 16 is provided at the center of the bottom plate 42a.
Has been installed. Therefore, the exhaust gas flowing out from the main catalyst body 2 makes a U-turn in the exhaust gas chamber 9 and the combustion cylinder 4
Passing through the outer peripheral side of the exhaust gas toward the lower part of FIG. 19 and exiting from the exhaust gas outlet 16.

According to the thirteenth embodiment, the exhaust gas flows on the outer peripheral side of the combustion cylinder 4, and the heat medium passes through the spiral passage 44 arranged on the outer peripheral side of the combustion cylinder 4, so that the exhaust gas and the heat are removed. Since the heat exchange with the medium is performed, the heat radiation from the outer peripheral side of the catalyst bodies 2 and 3 can be suppressed by the flow of the high-temperature exhaust gas. Therefore, as compared with the configurations of the first to twelfth embodiments, the catalyst body 2, It becomes easy to keep 3 at high temperature,
Good catalytic combustion can be maintained.

At the same time, there is an advantage that the heat insulating material 18 on the outer peripheral side of the combustion cylinder 4 in the first to twelfth embodiments can be eliminated. Furthermore, in the thirteenth embodiment, the eleventh and twelfth embodiments.
Compared with the heat exchanger integrated structure according to the embodiment, the combustion device has a small axial dimension and is horizontally long, so that it is easy to mount on a vehicle.

In the thirteenth embodiment, the spiral coil 43 of the eleventh embodiment is eliminated, but the first embodiment
Of course, as in the first embodiment, the spiral coil 43 may be arranged on the inner peripheral side of the fin 48. (Other Embodiments) In each of the above-described embodiments, a catalyst body is used as the starting catalyst body 3 for early activation of the catalyst.
The main catalyst body 2 was divided into
It may be used as one catalyst body.

Further, in the time charts of FIGS. 3 and 14, after the operation switch 22 is turned on, a predetermined time t1 + t2
It goes without saying that the increase in the combustion amount performed after the passage may be continuous or stepwise. Further, in FIG. 3, the operation time of the post-purge is regulated to the predetermined time t4 by the timer means, but instead of the regulation by this time, the temperature detected by the temperature detector 17 is the predetermined temperature after the start of the post-purge operation. The post-purge operation may be stopped when the temperature drops to 0.

Further, in the first embodiment and the like, as the fuel nozzle 10, a type in which the valve is opened to spray the fuel when the fuel supply pressure from the fuel pump 12 becomes equal to or higher than a predetermined pressure is used. As the nozzle 10, a two-fluid atomization type that simultaneously atomizes fuel and air may be used. Further, an ultrasonic nozzle for atomizing liquid fuel by ultrasonic waves, and an injector with an electric heater used for cold start of the engine in a vehicle equipped with an internal combustion engine, etc. May be used for the fuel nozzle 10.

When a known electromagnetic injector for vehicles is used as the fuel nozzle 10, the fuel supply amount can be controlled by controlling the energization time to the electromagnetic coil of the electromagnetic injector. It is possible to adopt a system in which the rotation speed of the pump 12 is kept constant and the fuel supply pressure is kept constant. Further, in the fifth and sixth embodiments and the like, the fuel absorber 27 is provided in the exhaust mixing cylinder 5,
The fuel absorber 27 may be omitted, and a spiral groove or the like may be formed on the inner wall surface of the exhaust mixing cylinder 5, and the fuel retaining effect may be enhanced in this groove to improve the evaporation property.

Further, the present invention is not limited to liquid fuel such as kerosene as the fuel, but may be carried out using gaseous fuel such as natural gas.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is an electrical control block diagram according to the first embodiment of the present invention.

FIG. 3 is an operation explanatory view of the first embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view showing a second embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view showing a third embodiment of the present invention.

FIG. 6 is a vertical sectional view showing a fourth embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view showing a fifth embodiment of the present invention.

FIG. 8A is a sectional view of a main part of a fuel nozzle used in the fifth embodiment, and FIG. 8B is a top view of a first plate-shaped member of the fuel nozzle.

9 is an operating characteristic diagram of the fuel nozzle shown in FIG.

10A is a vertical cross-sectional view showing a sixth embodiment of the present invention, and FIG. 10B is a top view of a deflection plate used in the sixth embodiment.

FIG. 11 is a vertical sectional view showing a seventh embodiment of the present invention.

FIG. 12 is a vertical sectional view showing an eighth embodiment of the present invention.

13A is a vertical cross-sectional view showing a starting catalyst body according to an eighth embodiment, and FIG. 13B is a partially enlarged view of the starting catalyst body.

FIG. 14 is an operation explanatory view of the eighth embodiment.

FIG. 15 is a vertical sectional view showing a ninth embodiment of the present invention.

FIG. 16 is a vertical sectional view showing a tenth embodiment of the present invention.

FIG. 17 is a vertical sectional view showing an eleventh embodiment of the present invention.

FIG. 18 is a vertical sectional view showing a twelfth embodiment of the present invention.

FIG. 19 is a vertical sectional view showing a thirteenth embodiment of the present invention.

[Explanation of symbols]

2, 3 ... Catalyst body, 2b, 3b ... Through hole, 4 ... Combustion cylinder, 5
... Exhaust gas mixing cylinder, 6 ... Primary nozzle, 6a ... Throttling part, 6b ...
Secondary nozzle, 7 ... Air pump, 9 ... Exhaust gas chamber, 10 ...
Fuel nozzle, 12 ... Fuel pump, 13 ... Premixing chamber, 14
... Fuel absorber, 15 ... Electric heater, 19 ... Insulation material, 24
... auxiliary electric heater, 27 ... fuel absorber, 28 ... deflector,
30 ... Conductive starting catalyst body, 40 ... Heat exchanger.

Continuation of the front page (56) Reference JP-A-4-320710 (JP, A) JP-A-1-296003 (JP, A) JP-A-59-167621 (JP, A) JP-A-6-94225 (JP , A) JP 53-8024 (JP, A) JP 4-148105 (JP, A) JP 57-33712 (JP, A) JP 58-86314 (JP, A) JP 1-306711 (JP, A) JP-A-6-101819 (JP, A) JP-A-2-21105 (JP, A) JP-A 61-11515 (JP, A) JP-A 56-25602 (JP, A) A) JP-A-4-208311 (JP, A) JP-A-62-33213 (JP, A) JP-A-6-317305 (JP, A) JP-A-56-59117 (JP, A) JP-A-5 -196211 (JP, A) JP-A-6-2820 (JP, A) JP-A-6-137523 (JP, A) JP-A-4-314613 (JP, A) JP-A-7-110114 (JP, A) ) JP-A-60-30908 (JP, A) Actually opened 60-76736 (JP, U) Actually opened 49-104028 (JP, U) Open Akira 61-135127 (JP, U) JitsuHiraku Akira 57-87920 (JP, U) (58 ) investigated the field (Int.Cl. ^7, DB name) F23D 14/18 F23D 11/40 F23C 11/00

Claims (20)

(57) [Claims] 1. A fuel supply means (10, 1) for supplying fuel.
2), a combustion air supply means (7, 8) for supplying combustion air, a catalyst body (2, 3) for catalytically burning a mixture of the fuel and the combustion air, and the catalyst body (2 ,
3) and a combustion tube (4), and the catalyst body (2, 3) has a through hole (2b,
3b) is formed in a ring shape, and the fuel supply means (10, 12) and the combustion air supply means (7, 7) are provided on one end side of the catalyst bodies (2, 3).
8) is provided, and a premixing chamber (13) that forms a mixture of the fuel and the combustion air is provided at a site on the other end side of the catalyst bodies (2, 3). From the one end side of the medium (2, 3), the through hole (2
b, 3b), the fuel and the combustion air are supplied to the premixing chamber (13), and the premixing chamber (1)
In 3), the fuel and the combustion air are mixed, and the air-fuel mixture is turned in the premixing chamber (13) to move the inside of the catalyst body (2, 3) from the other end side to the one end side. Te flow, so as recirculating part of the exhaust gas after the catalyst body passage at one end side of the catalyst body (2, 3) to the combustion air from the combustion air supply means (7) cage, through holes in the center of the catalyst (2,3) (2b, 3b)
Of the exhaust gas after passing through the combustion air and the catalytic body.
An exhaust mixing cylinder (5) for mixing with the
The exhaust mixing cylinder (5) has a cross-sectional area toward the downstream side.
Pressure riser consisting of a circular pipe with an expanding divergence (5
b) is formed, The catalytic combustion device characterized by the above-mentioned. 2. The pressure in the exhaust mixing cylinder (5)
The inlet side of the rising part (5b) consists of a circular pipe part with an equal cross-sectional area.
The catalytic combustion device according to claim 1, characterized in that a mixing portion (5a) is formed . 3. A primary nozzle (6) having a throttle portion (6a) that throttles the flow of the combustion air is disposed adjacent to one end side of the catalyst bodies (2, 3), and the throttle is provided. The part of the exhaust gas after passing through the catalyst bodies (2, 3) is caused to recirculate into the combustion air by the pressure reducing action of the portion (6a). Catalytic combustion device. 4. The exhaust part (6a) is arranged in the central part of the exhaust mixing cylinder (5), and the exhaust gas after passing through the catalyst bodies (2, 3) from the outer peripheral side of the restrictor part (6a). The catalytic combustion device according to claim 3, wherein a part of the gas is returned to the combustion air. 5. A ring-shaped secondary nozzle (6b) for recirculating a part of the exhaust gas after passing through the catalyst bodies (2, 3) into the combustion air on the outer peripheral side of the throttle portion (6a). The catalytic combustion device according to claim 4, wherein the catalytic combustion device is provided. 6. The fuel is a liquid fuel, and a fuel absorber (14) for absorbing and evaporating the supplied liquid fuel is provided inside the premixing chamber (13). The catalytic combustion device according to any one of claims 1 to 5. 7. The ring-shaped catalyst bodies (2, 3) are axially divided into a plurality of pieces, and the plurality of catalyst bodies (2, 3) are closer to the premixing chamber (13) side. The catalyst combustion apparatus according to any one of claims 1 to 6, characterized in that the amount of supported catalyst is increased. 8. An exhaust gas chamber (9) filled with exhaust gas after passing through said catalyst body (2, 3) is formed at one end side of said catalyst body (2, 3). The heat exchange is possible between the exhaust gas in 9) and the combustion air supplied from the combustion air supply means (7). Catalytic combustion device. 9. The heat insulating material (18) is arranged around the premixing chamber (13) and the catalyst body (2, 3), according to any one of claims 1 to 8. The catalytic combustion device described. 10. The fuel is a liquid fuel, and the fuel supply means is provided with a fuel nozzle (10) having a characteristic that a fuel spray angle increases as the liquid fuel flow rate increases, and when the liquid fuel flow rate is large. Is the fuel nozzle (10)
The spray angle of the fuel sprayed from is increased to direct the sprayed fuel from the fuel nozzle (10) toward the inner wall surface of the through holes (2b, 3b) of the catalyst body (2, 3). The catalytic combustion device according to any one of claims 1 to 9. 11. The fuel is liquid fuel, and the liquid fuel supplied from the fuel supply means (10, 12) to the inner wall surfaces of the through holes (2b, 3b) of the catalyst bodies (2, 3). A deflection plate (28) for deflecting the flow is provided, and when the liquid fuel flow rate is large, the deflection plate (28) supplies the fuel supplied from the fuel supply means (10, 12) to the catalyst body (2, 3). The catalytic combustion device according to any one of claims 1 to 9, wherein the catalytic combustion device is directed toward the inner wall surface of the through hole (2b, 3b). 12. The through hole (2) of the catalyst body (2, 3).
The catalytic combustion device according to claim 10 or 11, characterized in that a fuel absorber (27) for absorbing and evaporating the supplied liquid fuel is provided on the inner wall surface of (b, 3b). 13. An electric heater (15) is arranged in the premixing chamber (13).
2. The catalytic combustion device according to any one of 2. 14. The electric heater (15) is energized at the time of starting the combustion operation, and after a lapse of a predetermined time (t1) from the energization, the supply of the fuel and the combustion air is started in a small amount, and then the touch operation is further performed. When the exhaust gas temperature after passing through the medium (2, 3) reaches a first predetermined temperature (T1), the supply amounts of the fuel and the combustion air are continuously or stepwise increased, and then the catalyst body is further added. (2, 3) The energization to the electric heater (15) is stopped when the exhaust gas temperature after passing becomes a second predetermined temperature (T2) higher than the first predetermined temperature (T1). Claim 1
3. The catalytic combustion device according to item 3. 15. An auxiliary electric heater (24) for heating the combustion air supplied from the combustion air supply means (7).
15. The catalytic combustion apparatus according to claim 14, further comprising: a heater for supplying electricity to the auxiliary electric heater (24) when the electric heater (15) is energized. 16. A starting catalyst body (30) having conductivity is arranged closer to the premix chamber (13) side than the ring-shaped catalyst body (2), and the starting catalyst body (30) is The catalyst body (30) is configured to be energizable from the outside, and the energization of the starting catalyst body (30) causes the starting catalyst body (30) itself to generate heat as an electric resistor. 13. The catalytic combustion device according to any one of 1 to 12. 17. The conductive catalyst for starting (30) is energized at the time of starting the combustion operation, and a predetermined time (t
1) After a lapse of time, the supply of the fuel and the combustion air is started in a small amount, and then the exhaust gas temperature after passing through the ring-shaped catalyst body (2) and the starting catalyst body (30) is the first When the temperature reaches a predetermined temperature (T1), the supply amounts of the fuel and the combustion air are continuously or stepwise increased, and then the exhaust gas temperature after passing through both the catalyst bodies (2, 30) is the first temperature. 17. The catalytic combustion device according to claim 16, wherein energization to the starting catalyst body (30) is stopped at a time point when a second predetermined temperature (T2) higher than the predetermined temperature (T1) is reached. 18. The ring-shaped catalyst body (2) is electrically conductive and can be energized from the outside, and the ring-shaped catalyst body (30) is energized when the starting catalyst body (30) is energized. Power is also applied to 2), and both catalyst bodies (2, 3)
The catalytic combustion device according to claim 17, wherein 0) is used as an electric resistor to generate heat. 19. A heating medium for heating and a catalyst body (2, 3, 3) are provided at one end of said catalyst body (2, 3, 30).
0) The catalyst according to any one of claims 1 to 18, wherein a heat exchanger (40) for heating the heat medium for heating is built in by exchanging heat with the exhaust gas that has passed through. Combustion device. 20. A heat transfer medium for heating and a heat transfer medium for heating are exchanged with the exhaust gas after passing through the catalyst bodies (2, 3, 30) on the outer peripheral side of the combustion cylinder (4). 19. The catalytic combustion device according to claim 1, further comprising a heat exchanger (40) for heating the.