JPH10153306A - Catalytic combustion device - Google Patents

Abstract

(57) [Summary] In a catalytic combustion device, a good catalytic combustion is realized by securing a preheating effect of combustion air by exhaust gas circulation, and the structure is reduced in size and simplified. SOLUTION: A ring-shaped catalyst body 2, 3 for catalytically combusting an air-fuel mixture of fuel and combustion air is provided in a combustion cylinder 4, and one end of the catalyst body 2, 3 in the combustion cylinder 4 is provided with a fuel nozzle. 10
In addition, an inlet 8 for combustion air is provided, and a premixing chamber 13 for forming an air-fuel mixture of fuel and combustion air is provided inside the combustion cylinder 4 at the other end of the catalyst bodies 2 and 3. From one end sides of the catalyst bodies 2 and 3, through holes 2b and 3b at the center of the catalyst bodies 2 and 3
, The fuel and the combustion air are supplied to the premixing chamber 13, and the fuel and the combustion air are mixed in the premixing chamber 13. This air-fuel mixture is diverted in the premixing chamber 13 and flows from the other end of the catalyst body 2, 3 toward one end, and the exhaust gas after passing through the catalyst body at one end of the catalyst body 2, 3. A part is returned to the combustion air.

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, and is suitable for use in, for example, a heating device and a drying device.

[0002]

2. Description of the Related Art Conventionally, 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. I have. In this catalytic combustion device, no flame is formed, and thus no carbon is generated. In addition, the catalytic combustion device can significantly suppress the occurrence of ignition and exhaust emission during flame combustion, so it is very effective especially as a heating device for electric vehicles requiring clean exhaust gas. is there.

In order to continue catalytic combustion in the catalytic combustion apparatus, it is necessary to always preheat the combustion air to activate the catalyst. The power increases. Particularly, in an electric vehicle, use of an electric heater that causes an increase in power consumption is not suitable due to a limitation of a battery capacity. In addition, if the combustion air is preheated by a burner, carbon adheres to the catalyst, which causes a reduction in the combustion efficiency of the catalyst. In addition, at the time of ignition, the catalyst is not sufficiently activated due to the low temperature, so that there is a problem that the exhaust emission generated in the burner is directly discharged.

To solve such a problem, Japanese Patent Laid-Open Publication No.
Japanese Patent Application Publication No. 0-30908 discloses a configuration in which the front and rear of a catalytic combustion device are connected by an exhaust gas circulation pipe, and a part of exhaust gas is recirculated to an upstream side of the catalytic combustion device to preheat combustion air. I have. In addition, Japanese Patent Application Laid-Open No. 4-320710
In the publication, when a raw material gas in which 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 a jet nozzle, and the pressure is reduced by the increased speed. A system in which a part of the exhaust gas is recirculated into the source gas to preheat the source gas has been proposed.

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

[0006]

However, in the former conventional device, since the exhaust gas circulation pipe is installed outside the combustion device, an increase in physique is inevitable. As a result, there is a problem that mounting of the heating device becomes difficult. Further, in the latter conventional device, since it is necessary to mix air and fuel in advance, a separate device for this mixing is required.Moreover, a large number of gas passages for the catalyst layer are provided, and the gas passages are provided in the gas passages. Since a large number of ejection nozzles are provided correspondingly, the number of components is inevitably increased, the configuration is complicated, and the cost is increased.

[0007] The present invention has been made in view of the above points,
In a catalytic combustion device, it is an object to secure a preheating effect of combustion air by exhaust gas circulation, realize favorable catalytic combustion, and reduce the size and simplification of the configuration.

[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 No. 0, a ring-shaped catalyst (2, 3) for catalytically combusting a mixture of fuel and combustion air is built in a combustion cylinder (4), and the catalyst (2, 3) Supply means for fuel and combustion air (10, 12, 7) at one end side
And a premixing chamber (13) for forming an air-fuel mixture of fuel and combustion air is provided at the other end of the catalyst body (2, 3). Further, fuel and combustion air are supplied from one end of the catalyst body (2, 3) to the premixing chamber (13) through the central through holes (2b, 3b) of the catalyst body (2, 3). The fuel and the combustion air are mixed in the premixing chamber (13). Then, the air-fuel mixture is changed in direction in the premixing chamber (13), and flows through the catalyst body (2, 3) from the other end to one end. Catalyst body (2,
3) It is characterized in that part of the exhaust gas after passing is recirculated into the combustion air.

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. Can be performed continuously and stably. In addition, the entire mechanism for recirculating a part of the exhaust gas into the combustion air can be accommodated in the combustion tube (4), so that the size of the combustion device can be reduced.

In the present invention, the fuel and the combustion air are
The through hole (2b, 2) at the center of the ring-shaped catalyst body (2, 3)
After passing through 3b), the direction is changed in a U-turn in the premixing chamber (13) so that the catalyst body (2, 3) flows from the other end to one end. -3207
As compared with the combustion apparatus disclosed in Japanese Patent Application Publication No. 10-103, the number of parts can be significantly reduced, the configuration can be extremely simplified, and the cost can be reduced at a low cost. Can be manufactured.

According to the invention, when a liquid fuel is used as the fuel, the 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 wide area of the fuel absorber (14), thereby uniformly mixing the fuel and the air. A state is formed, and a good combustion state can be realized.

According to the seventh aspect of the invention, the ring-shaped catalyst body (2, 3) is divided into a plurality in the axial direction, and the amount of catalyst carried on the plurality of catalyst bodies (2, 3) is estimated. Since the number of catalysts increases as the distance to the mixing chamber (13) increases, of the plurality of catalysts (2, 3), the closer to the premixing chamber (13) side (the more upstream), the lower the temperature. The catalyst can be activated, so that catalytic combustion can be performed favorably from the start. Further, even if the amount of the catalyst carried on the downstream side is small, the temperature of the catalyst body rises due to the radiation of the catalytic combustion heat on the upstream side and the high-temperature exhaust gas reaction heat, so that the catalyst body can be activated early.

According to the invention, an exhaust gas chamber (9) filled with exhaust gas after passing through the catalyst (2, 3) is formed at one end of the catalyst (2, 3). Since 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), the combustion air is supplied to the exhaust gas chamber. (9) It becomes possible to preheat with the exhaust gas inside, 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).
Spray fuel from the catalyst (2, 3) through holes (2b, 3).
It is characterized in that it is directed to the direction of the inner wall surface of b).

Thus, at the time of maximum combustion when the flow rate of the liquid fuel is large, the heat transfer from the catalyst body (2, 3), which is a high temperature portion, is used to improve the evaporability of the liquid fuel and achieve good combustion. Can be secured. According to the eleventh aspect, the flow of the liquid fuel supplied from the fuel supply means (10, 12) is deflected to the inner wall surfaces of the through holes (2b, 3b) of the catalyst bodies (2, 3). When the liquid fuel flow rate is large, the deflecting plate (28) allows the fuel supplied from the fuel supply means (10, 12) to pass through the through holes (2b, 3b) of the catalyst body (2, 3). ) Is directed to the direction of the inner wall surface.

[0016] Thus, in the same manner as in the tenth aspect, at the time of maximum combustion, the heat transfer from the catalyst body (2, 3), which is a high temperature portion, can be used to improve the evaporability of the liquid fuel. Further, according to the twelfth aspect, the fuel absorber (27) for absorbing and evaporating the supplied liquid fuel on the inner wall surface of the through hole (2b, 3b) of the catalyst body (2, 3). It is characterized by having.

According to the present invention, when the evaporability of the liquid fuel is improved by utilizing the heat transfer from the catalyst body (2, 3), the fuel absorber (27) is provided to provide the fuel. And the evaporability can be further improved. According to the thirteenth aspect of the present invention, since the electric heater (15) is disposed in the premixing chamber (13),
The air-fuel mixture can be preheated by the electric heater (15) at the time of starting combustion, and catalytic combustion can be favorably performed immediately after the start of combustion.

According to the fourteenth aspect of the present invention, the electric heater (15) is energized at the start of 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. Then, the catalyst body (2,
3) When the exhaust gas temperature after the passage reaches the first predetermined temperature (T1), the supply amounts of the fuel and the combustion air are increased continuously or stepwise, and then further after passing through the catalyst body (2, 3). When the exhaust gas temperature 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 amount of supply of fuel and air and the power supply to the electric heater (15) are automatically controlled in relation to the exhaust gas temperature 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, an auxiliary electric heater (24) for heating the combustion air supplied from the combustion air supply means (7, 8) 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 generated by the auxiliary electric heater (24) in extremely cold weather or the like, and the startability of combustion is improved. Can be improved.

According to the sixteenth aspect of the present invention, the starting catalyst body (30) having conductivity is located closer to the premixing chamber (13) than the ring-shaped catalyst body (2).
And the starting catalyst body (30) is configured to be able to conduct electricity from the outside, and by energizing the starting catalyst body (30), the starting catalyst body (30) itself generates heat as an electric resistor. It is characterized by having

Thus, since the catalyst can be directly heated by the heat generated by the starting catalyst body (30) itself, the starting catalyst body (3) can be heated by radiant heat from the electric heater (15). ) Can be improved in preheating effect of the catalyst as compared with the case of preheating, and power consumption can be reduced by improving the preheating effect. And, with the improvement of the preheating effect of the starting catalyst body (30), the startup time of catalytic combustion can be shortened even at low temperatures. Moreover, the elimination of the electric heater (15) makes it possible to reduce the size of the entire apparatus and to reduce the cost by simplifying the structure.

According to the seventeenth aspect of the present invention, the conductive start-up catalyst (30) is energized at the start of the combustion operation, and after a predetermined time (t1) has elapsed from the energization, the fuel and the combustion air are discharged. The supply is started in a small amount, and thereafter, when 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 combustion air are further increased. 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 some point, the starting catalyst (3
The present invention is characterized in that the energization to 0) is stopped, so that the combustion operation can be satisfactorily automatically controlled as in the fourteenth aspect.

According to the present invention, the ring-shaped catalyst body (2) has conductivity and can be energized from the outside, and the energization of the starting catalyst body (30) is performed. Sometimes, the ring-shaped catalyst (2) is also energized,
The two catalysts (2, 30) are characterized in that they generate heat as electric resistors, so that both catalysts (2, 30) can be produced even at extremely low temperatures such as, for example, −20 ° C. or less. By simultaneous energization to 30), both catalysts of both catalyst bodies (2, 30) can be directly heated by the electric heating action and activated early. Therefore, even at extremely low temperatures, the combustion start-up time can be reduced, and rapid heating can be achieved.

According to the nineteenth aspect of the present invention, a heat medium for heating and a heat medium 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
Heat exchanger for heating the heat medium (40)
Can provide a compact catalytic combustion device.

According to the twentieth aspect, the heat exchange between the heating medium for heating and the exhaust gas after passing through the catalysts (2, 3, 30) is performed on the outer peripheral side of the combustion tube (4). Since the heat exchanger (40) for heating the heating medium for heating is built in, the compact catalytic combustion in which the heat exchanger (40) for heating the heating medium is integrated as in the case of claim 19 The heat exchanger (4) can be provided on the outer peripheral side of the combustion cylinder (4).
Since (0) is arranged, the dimension of the combustion cylinder (4) in the axial direction (height direction) can be reduced, and the mountability to a vehicle or the like can be further improved.

The symbols in parentheses of the above-mentioned means indicate the correspondence with the concrete means described in the embodiments described later.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS 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, in which the combustion device of this example is applied to a heating device for an electric vehicle. The vertical direction in FIG. Matches. Reference numeral 1 denotes a combustion device having a cylindrical shape having a vertical axis in FIG. Reference numeral 2 denotes a main catalyst body incorporated in the combustion device 1 and has a ring-shaped (cylindrical) shape having a hollow central portion. Reference numeral 3 denotes a starting catalyst body, which is disposed adjacent to the lower end surface side of the main catalyst body 2 with a small gap A therebetween, and has a ring-like shape like the main catalyst body 2. 2b and 3b are through holes at the center of the ring shape.

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 a low temperature (for example, 2).
Noble metal catalyst (Pt, Pt)
d)) (the ratio of the amount of catalyst to the total weight of the catalyst body) is larger than that of the main catalyst body 2. The minute interval A between the main catalyst 2 and the starting catalyst 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 respectively supported on honeycomb-shaped carriers 2a, 3a made of ceramic or the like. The outer peripheral surfaces of the main catalyst body 2 and the starting catalyst body 3 are supported and fixed on the inner wall surface of the combustion cylinder 4. The combustion cylinder 4 defines the main body of the combustion device 1 and is formed of a heat-resistant metal such as stainless steel into a bottomed cylindrical shape. Inside the combustion cylinder 4, a combustion chamber is constituted by a portion containing the catalyst bodies 2 and 3.

Reference numeral 5 denotes an exhaust mixing cylinder made of a heat-resistant metal such as stainless steel, and its overall shape is formed in a substantially cylindrical shape. This 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 these two catalyst bodies 2, 3 to be integrated. ing. Here, the exhaust mixing cylinder 5 has a mixing portion 5a formed of a circular pipe portion having an equal cross-sectional area at one end side (combustion air and fuel inlet side), and a gentle divergence angle at the other end side. The pressure increasing portion 5b is formed of a circular tube having a diameter of, for example, about 5 to 10 degrees. In addition, a tapered enlarged end 5c is formed at the inlet end of the mixing section 5a.

Reference numeral 6 denotes a primary nozzle, which is disposed in the combustion cylinder 4 adjacent to one end of the main catalyst 2. The primary nozzle 6 has a narrowed portion 6 narrowed in a funnel shape on the lower end side.
a and is formed of a 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 an air inlet 8 to an inner space 60 of the primary nozzle 6.

The throttle portion 6a of the primary nozzle 6 is inserted by a predetermined amount into the tapered enlarged end portion 5c of the exhaust mixing cylinder 5, and a ring is provided between the tapered enlarged end portion 5c and the throttle portion 6a. A secondary nozzle 6b having a shape is formed. The secondary nozzle 6 b is for recirculating the exhaust 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 separated 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 serves as a partition member that partitions the inner space (fuel and air supply side space) 60 from the exhaust gas chamber 9.
Reference numeral 10 denotes a fuel nozzle which sprays 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, the air pump 7 is provided in the inner space 60 of the primary nozzle 6.
An air inlet 8 and a fuel nozzle 10 are opened. Here, in the present embodiment, the fuel supply means is constituted by the fuel nozzle 10 and the fuel pump 12.

Reference numeral 13 denotes a premixing chamber for mixing the liquid fuel and the combustion air. The premixing chamber is disposed inside the combustion cylinder 4 at the other end (lower end) of the main catalyst 2 and the starting catalyst 3. . 14
Is a wire mesh fuel absorber made of a heat-resistant metal, which is arranged over a wide area from the inner surface to the side surface of the bottom wall of the premixing chamber 13. Here, as the fuel absorber 14,
In addition to a wire mesh member (wick), a foamed 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 flow of the mixture of fuel and air from the center to the radially outward side. Therefore, the central portion has a shape protruding in a mountain shape. 1
3a is the protrusion. Reference numeral 15 denotes an electric heater arranged in the premixing chamber 13, which is, for example, a sheath heater bent in a spiral shape, and is used to heat the starting catalyst 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 denotes an exhaust gas outlet for discharging exhaust gas from the exhaust gas chamber 9 to the outside. Reference numeral 17 denotes a temperature detector (thermistor) provided in the exhaust gas chamber 9 near the exhaust gas outlet 16. Reference numeral 18 denotes a heat insulating material provided over the entire outer periphery of the combustion tube 4, and a cover 19 is provided with the heat insulating material 18 interposed therebetween. 20 is a combustion cylinder 4 and a cover 19
Is an upper end plate for closing the upper end opening of the upper end plate.
The fuel nozzle 10 and the air inlet 8 are attached to the fuel cell.

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 a heater core of an air conditioner by a pump, and the conditioned air is heated by the heater core to heat the vehicle interior. FIG. 2 is an electric control block diagram of the first embodiment. Reference numeral 21 denotes a control device that controls the electric devices (7, 12, 15) in a combustion measure, and reference numeral 22 denotes an operation switch of the combustion device 1.

Next, the operation of the above configuration will be described.
Now, when the operation switch 22 is turned on, the controller 21 first energizes the electric heater 15 and the electric heater 15
The starting catalyst 3 and the fuel absorber 14 are preheated by the heat generated by the heating. A predetermined time t1 since the operation switch 22 was turned on (FIG. 3)
After that, the air pump 7 and the fuel pump 12 are energized by the timer means in the control device 21, so that the supply of combustion air and fuel is started.

Here, the supply amounts of combustion air and fuel are as follows:
First, the control unit 21 sets the rotation speeds of both the pumps 7 and 12 to a low rotation speed, and sets the rotation speed to 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 flows from the beginning, the starting catalyst 3 and the fuel absorber 14 may be cooled and catalytic reaction may not be performed.

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 inside. Then, the liquid fuel sprayed from the nozzle 10 is jetted downward in the exhaust mixing cylinder 5 and the premix chamber 13
It evaporates on the fuel absorber 14 inside and is mixed with the combustion air. This air-fuel mixture changes direction in the premixing chamber 13 (U-turn)
Then, the fuel flows into the starting catalyst body 3 from below toward above, reacts with the starting catalyst body 3, and burns.

The main catalyst 2 emits radiation from the starting catalyst 3,
, And gradually heated by the high-temperature reaction gas. After the start of supply of fuel and air, a predetermined time t shown in FIG.
2 has elapsed, or when the temperature detected by the temperature detector 17 provided in the exhaust gas chamber 9 reaches a first predetermined temperature T1 (for example, about 300 ° C. in the case of kerosene fuel), the controller 2
The number of revolutions 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 from the exhaust gas outlet 16 to the outside.

Then, the temperature detected by the temperature detector 17 becomes the second temperature.
Predetermined temperature T2 (for example, about 500 ° C. for kerosene fuel)
Is reached, it is determined that the main catalyst 2 has been activated, and the control device 21 stops energizing the electric heater 15 and thereafter shifts to steady combustion. Instead of determining that the temperature detected by the temperature detector 17 is greater than the predetermined temperature T2, a predetermined time t3 shown in FIG. 3 is set by timer means, and the power supply to the electric heater 15 is stopped after the predetermined time t3 has elapsed. May be.

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 the same 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 returned to the exhaust mixing cylinder 5 through the secondary nozzle 6b. Here, since the exhaust mixing cylinder 5 is provided with a pressure rising 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 rising portion 5b. The air-fuel mixture converts its velocity component into pressure and recovers pressure.

As described above, in the apparatus according to the present embodiment, the combustion air can be preheated with high-temperature exhaust gas heat by recirculating a part of the exhaust gas in the exhaust gas chamber 9 into the combustion air. 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 in opposite directions inside and outside the primary nozzle 6. Therefore, the combustion air can be preheated by the exhaust gas through the heat conduction through the metal primary nozzle (partition member) 6, and the preheating effect of the combustion air can be further enhanced.

To stop the combustion, 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 remaining fuel in the combustion cylinder 4, and then cools the interior of the combustion cylinder 4 (post-purge). operation). Then, a predetermined time t4
After the elapse, the air pump 7 is also stopped, and all the devices are stopped.

The features of the first embodiment described above are summarized as follows. When the catalysts 2 and 3 are activated, the fuel supply,
Since the stop is performed, almost no exhaust emission is emitted even during ignition or digestion, and clean combustion can be performed. At the time of starting, the preheating of the fuel and the catalyst is performed in the premixing chamber 1.
Efficient combustion is achieved with one electric heater 15 provided in 3 and exhaust gas recirculation is used for preheating combustion air during steady combustion, so that an electric heater is not required, and power saving and efficient combustion are possible. Becomes (Second Embodiment) FIG. 4 shows a second embodiment according to the present invention. In the first embodiment, a primary nozzle 6 for ejecting combustion air is disposed at one end of the catalyst bodies 2 and 3 at the center of the combustion cylinder 4, and an exhaust gas is ejected on an outer peripheral side of the primary nozzle 6 by an ejector effect. Is formed, but in the second embodiment, the primary nozzle 6 and the secondary nozzle 6b are arranged in reverse, that is, the secondary nozzle 6b
Are arranged on the center side, and the primary nozzle 6 is arranged in a ring shape on the outer peripheral side.

More specifically, in the second embodiment,
A combustion air chamber 23 partitioned from the exhaust gas chamber 9 is formed, and the air inlet 8 is connected to the combustion air chamber 23 to introduce combustion air. This introduction air
The ring-shaped primary nozzle 6 is ejected into the exhaust mixing cylinder 5. On the other hand, the secondary nozzle 6b is
The fuel nozzle 10 sprays only the liquid fuel inside the secondary nozzle 6b and does not supply combustion air to the inside of the secondary nozzle 6b. Further, the inner space of the secondary nozzle 6b is entirely open to the exhaust gas chamber 9 in the upper part thereof.

Therefore, the tip of the secondary nozzle 6b is depressurized by the ejector effect due to the ejection of the combustion air from the primary nozzle 6, and a part of the exhaust gas in the exhaust gas chamber 9 passes through the secondary nozzle 6b. The gas is returned into the exhaust mixing cylinder 5. According to the configuration of the second embodiment, the exhaust gas flowing around the inner and outer peripheries of the combustion air chamber 23 causes a wide heat exchange (heat) before the combustion air supplied from the air inlet 8 enters the exhaust mixing cylinder 5. The combustion) air can be preheated by the (conduction) area. Therefore, the preheating of the combustion air can be performed efficiently. The other effects are the same as those of the first embodiment. (Third Embodiment) FIG. 5 shows a third embodiment in which the combustion startability at a low temperature is improved with respect to the first embodiment. To this end, as shown in FIG.
The auxiliary electric heater 24 composed of a C heater or the like is connected to the primary nozzle 6
Is spirally disposed in the inner space 60 of the helical member. Thus, at the time of low-temperature start-up in an extremely cold region or the like, the auxiliary electric heater 24 is energized simultaneously with energization of the electric heater 15, thereby improving the effect of preheating the combustion air and improving the combustion startability. (Fourth Embodiment) FIG. 6 shows a fourth embodiment. In each of the first to third embodiments, the catalyst bodies 2, 3
Is carried on the honeycomb-shaped carriers 2a, 3a, but in the fourth embodiment, a large number of the granular catalysts 2,
3 is disposed in a hollow double cylindrical body 25, and the granular catalyst bodies 2 and 3 are held in the double cylindrical body 25 by a supporting member 26 made of wire mesh. The present invention can be implemented even with such a configuration. (Fifth Embodiment) In all of the first to fourth embodiments described above, since all the liquid fuel is sprayed from the fuel nozzle 10 toward the fuel absorber 14 in the premixing chamber 13, the fuel is evaporated. Is performed in the fuel absorber 14, but when the combustion mode (fuel flow rate) increases due to the transition to steady-state combustion, the fuel absorber 14 evaporates all of the increased fuel. Insufficient capacity may result in worse fuel evaporation.

In view of the above, in the fifth embodiment, even at the time of the maximum combustion amount, the heat of the high temperature portion inside the combustion device is effectively utilized to improve the evaporability of the liquid fuel. . That is, FIGS. 7 to 9 show the fifth embodiment, in which a swirl type fuel nozzle shown in FIG. This swirl type fuel nozzle 10 has a pipe-shaped housing 10a made of a heat-resistant metal such as stainless steel as shown in FIG.
b is open.

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

The circular swirling chamber 10e of the fuel introduction hole 10g.
The opening direction with respect to the swirl chamber 10e is tangential to the swirl chamber 10e, so that the fuel from the flat side surface 10f can be circularly swirled.
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 for gradually reducing the cross-sectional area of the circular swirl chamber 10e, and a throttle hole 10i is provided at the tip of the tapered surface 10h. The two plate-like members 10c and 10d are preferably formed of free-cutting brass having excellent cutting workability.

In the swirl type fuel nozzle 10 having such a configuration, 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. Has increasing properties. 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 section 5a of the exhaust mixing cylinder 5 to the entire length of the pressure increasing section 5b. Here, the fuel absorber 27 is a fuel absorber 1 in the premixing chamber 13.
As in the case of No. 4, it can be composed of a wire mesh member made of a heat-resistant metal or the like.

According to the fifth embodiment, when the combustion amount (fuel flow rate) is small, such as at the start of combustion, the swirling force of the fuel in the swirl type fuel nozzle 10 is small, so that the fuel spray angle is about 10 °. Is small. Therefore, the fuel sprayed from the fuel nozzle 10 is not adsorbed by 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, and the fuel absorber 14 receives heat from the electric heater 15 and evaporates.

At this time, since the fuel flow rate is small, the fuel can be satisfactorily evaporated only with the fuel absorber 14. On the other hand, if the combustion amount (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 at the time of maximum combustion, the fuel spray angle increases to about 40 °.

As described above, as the fuel spray angle from the fuel nozzle 10 increases, a part of the fuel spray from the fuel nozzle 10 comes into contact with the fuel absorber 27 in the exhaust mixing cylinder 5 (see FIG. 7). It is adsorbed. Here, the fuel absorber 27 is heated and transferred from the catalyst members 2 and 3 in the high-temperature portion via the metal wall surface of the exhaust mixing cylinder 5 and is heated.
The fuel evaporates well in the fuel absorber 27.

That is, compared to the case where the fuel is adsorbed only to the fuel absorber 14 in the premixing chamber 13 as in the first to fourth embodiments, according to the fifth embodiment, the fuel spray is used. 14 and the fuel absorber 27,
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 the 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 omitted, and The same fuel nozzle 10 as that of 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, a fuel nozzle 10 of a type that opens and sprays fuel is used. In this type of fuel nozzle 10, the fuel spray angle is substantially constant regardless of the increase or decrease in the fuel flow rate.

Therefore, in the sixth embodiment, the exhaust mixing cylinder 5
A fuel absorber 27 is provided therein, and a deflection plate 28 for deflecting the flow of fuel is additionally provided. This deflection plate 28
Is made of a heat-resistant metal such as stainless steel.
As shown in the top view of (b), a circular ring portion 28a having an outer diameter equal to the inner diameter of the exhaust mixing cylinder 5 is provided, and a plurality of arms 28b are radially provided 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 disposed in the exhaust mixing cylinder 5 so as to face the fuel upstream side. In the example of FIG. 10, the deflection plate 28 is arranged near the upstream end of the pressure increasing portion 5 b in the exhaust mixing cylinder 5, 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 comes into contact with the deflection plate 28. At this time, when the fuel flow rate is low, such as at the time of starting, the fuel spray speed is low, and most of the fuel that has contacted and adhered to the deflection plate 28 hangs downward due to gravity. Therefore, most of the spray fuel from the fuel nozzle 10 reaches the fuel absorber 14 in the premix chamber 13 and evaporates there.

When the fuel flow rate is large, such as at the time of maximum combustion, the fuel spray speed is high.
A portion of the fuel sprayed from the fuel tank collides with the deflection plate 28 and rebounds, and thereafter, the colliding fuel 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 sprayed fuel can be dispersed and evaporated in both the fuel absorber 14 and the fuel absorber 27, so that the fuel can be satisfactorily evaporated even at the time of the maximum combustion. We can maintain state. (Seventh Embodiment) FIG. 11 shows a seventh embodiment in which the exhaust mixing cylinder 5 in the fifth embodiment is eliminated. That is, in the seventh embodiment, the exhaust mixing cylinder 5 is abolished,
The exhaust gas is mixed into the combustion air at the through holes 2b, 3b of the catalyst bodies 2, 3.

In this case, the efficiency of recirculating the exhaust gas into the combustion air decreases, but instead, the exhaust mixing cylinder 5
As a result, 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 been heated to a high temperature. In this case, if the fuel absorber 27 is provided on the inner wall surface of the main catalyst body 2, the fuel holding property on the inner wall surface of the main catalyst body 2 becomes good, and the fuel evaporation can be further improved.

As in the fifth embodiment, first to fourth
Needless to say, the exhaust mixing cylinder 5 can be eliminated also in the embodiment and the sixth embodiment. (Eighth Embodiment) In the first to seventh embodiments described above, the electric heater 15 is installed in the premixing chamber 13 and the starting catalyst body 3 having a small heat capacity is placed so as to face the premixing chamber 13. By installing and preheating the starting catalyst body 3 with 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, a conductive starting catalyst 30 is used in place of the electric heater 15 and the starting catalyst 3.

In FIG. 12, the conductive starting catalyst 3
Numeral 0 is disposed between the main catalyst 2 and the premixing chamber 13 with a small interval A interposed between the main catalyst 2 and the main catalyst 2. As shown in FIG. 13B, the starting catalyst body 30 is made of a thin metal plate.
For example, stainless steel (SUS430, plate thickness 0.05 m
The carrier 30a is formed by laminating a flat plate 30b made of m) and a corrugated plate 30c. After the catalyst is carried on the carrier 30a, the carrier 30a is wound many times to form a honeycomb disk shape as a whole. 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%. As shown in FIG. 13A, a positive electrode terminal 30d is arranged at the center of the starting catalyst body 30 and a negative electrode terminal 30e is arranged at the outer periphery, as shown in FIG. By supplying a power supply voltage between the terminals 30d and 30e, the starting catalyst 30 is energized. 8th
In the embodiment, the lower end portions of the exhaust mixing tube 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 tube 5 must be 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 interval A is about 5 mm. Other points are the same as those of the first to seventh embodiments. The operation in the eighth embodiment will be described. Now, when the operation switch 22 shown in FIG. 2 is turned on, power is supplied from the power supply (not shown) to the conductive starting catalyst 30 through the two electrode terminals 30d and 30e. here,
The power consumption of the starting catalyst 30 is, for example, 300 to 40.
Approximately 0W. By this energization, the starting catalyst body 30 acts as an electric heating element by its own electric resistance, and can directly and rapidly heat the catalyst carried on the carrier 30a.

At the same time, the main catalyst 2 and the fuel absorber 14 can be preheated by the radiant heat from the starting catalyst 3. After the operation switch 22 is turned on, FIG.
When the predetermined time t1 shown in FIG. 4 elapses, the air pump 7 and the fuel pump 12 are started to start supplying the combustion air and the fuel. The supply of combustion air and fuel is
Initially, the amount is very small, and is increased stepwise as time t2, t3, t3 'elapses. 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 power supply to the starting catalyst 30 is cut off.

According to the eighth embodiment, the starting catalyst 30
Metal catalyst carrier 30a acts as an electric heating element due to its own electric resistance, and can directly heat the catalyst carried on the carrier 30a. The preheating effect of the catalyst can be enhanced as compared with the case where the starting catalyst body 3 is preheated by radiant heat, and the power consumption can be reduced by improving the preheating effect.

Since the preheating effect of the main catalyst body 2 and the fuel absorber 14 can be improved with the improvement of the preheating effect of the starting catalyst body 30, even at a low temperature, the early activation of the catalyst and the fuel absorber 14 can be achieved. In combination with the promotion of fuel evaporation, the combustion start-up time can be shortened. Moreover, the elimination of the electric heater 15 can reduce the size of the entire apparatus,
The cost can be reduced by simplifying the structure.

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

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 temperature of the main Of course, the fuel may be directly sprayed on the inner peripheral wall. (Ninth Embodiment) FIG. 15 shows a ninth embodiment in which a plurality of, for example, three blocks 201 are formed by moving the main catalyst body 2 in the eighth embodiment in the flow direction of combustion air (vertical direction in the drawing). It is divided into 202 and 203. Then, the upstream side of the flow of combustion air (in FIG.
Side, that is, from block 203 to block 201, the catalyst activation temperature is lowered.

For this reason, in the present example, the amount of catalyst carried (the ratio of the amount of catalyst to the total weight of the catalyst body) increases from block 203 to block 201. Specifically, the loading amount of the catalyst is set to block 203: 0.5 wt%,
Block 202: 1.0 wt%, Block 201: 1.
5 wt%. Thereby, 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 using propylene gas by the present inventors, the catalyst activation temperature was 180 ° C. when Pt: 1.5 wt%, and Pt:
200 ° C for 1.0 wt%, Pt: 0.5 wt%
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 to the starting catalyst body 30, and the fuel flow rate can be rapidly increased accordingly. 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 in comparison with the case where the amount of catalyst carried in the main catalyst body 2 is kept constant at, for example, 0.5 wt% over the entire region. Therefore, the indoor heating effect can be rapidly activated.

Further, as compared with the case where the amount of the catalyst carried on the main catalyst body 2 is fixed at, for example, 1.5 wt% over the entire region, the amount of the expensive catalyst can be reduced without substantially changing the transition time to the maximum combustion amount. In addition, the cost can be reduced. Further, the main catalyst 2 is divided into a plurality of blocks 201 to 20.
Dividing into three and increasing the amount of supported catalyst toward the upstream side is effective not only at the time of starting heating but also at the time of steady combustion. That is, the combustion device of the present invention is not always used at the maximum combustion amount depending on the purpose of use, the use environment, and the like, and is desirably used over a wide combustion range. In catalytic combustion, the combustion temperature generally decreases as the amount of combustion decreases, and the reaction is completed on the upstream side of the catalyst.

Therefore, by setting the upstream catalyst block 201 to a low-temperature activation type, catalytic combustion can be performed up to a minute combustion region. As a means for lowering the activation temperature of the catalyst body, in addition to increasing the amount of the catalyst carried, the more the catalyst flows toward the upstream side of the flow of the combustion air (the part closer to the premixing chamber 13 in FIG. 1). The size of the medium may be reduced,
Further, increasing the amount of supported catalyst and reducing the size of the catalyst body may be combined.

Further, the material of the catalyst itself is changed (for example,
(Such as addition of Rh), the activation temperature may be lowered toward the upstream side of the flow of combustion air. In the present embodiment, the main catalyst body 2 is divided into three blocks 201 to 203. However, the number of divisions is not limited to three, and may be appropriately changed according to a target combustion rise time, a manufacturing cost, and the like. Of course you can.

Further, the main catalyst 2 is divided into a plurality of blocks 201.
It is also possible to increase the amount of supported catalyst toward the upstream side while maintaining the single main catalyst body 2 without dividing into the main catalyst body 2. (Tenth Embodiment) FIG. 16 shows a tenth embodiment, in which the main catalyst body 2 in the eighth embodiment is divided into two, and each of the two divided catalyst bodies is a conductive catalyst 204,
205, and a small interval B
(About 5 mm). The catalyst carriers 204a, 205a of the conductive catalysts 204, 205 have the eighth
The conductivity is given by the same configuration as the starting catalyst body 30 in the embodiment.

In this example, the two conductive catalysts 204, 2
Reference numeral 05 denotes a positive electrode terminal 204a, 2
05a, and electrode terminals 204b and 205b on the negative electrode side are disposed on the outer peripheral portion.
The two conductive catalysts 204 and 205 are electrically connected to each other in parallel. The outside air temperature is, for example, -20 ° C
At the following cryogenic temperatures, rapid activation of the catalyst is difficult despite the need for rapid heating.
According to the embodiment, by simultaneously energizing the three members of the starting catalyst body 30 and the two conductive catalyst bodies 204 and 205, the three catalysts are all supported by the carriers 204a, 205a, and 30.
It can be activated early by direct heating by the electric heating effect of a. Therefore, it is possible to shorten the combustion start-up time even at an extremely low temperature.

On the other hand, when the outside air temperature is relatively high (for example,
(In the case of 10 ° C. or more), only the starting catalyst body 30 is energized, and the two conductive catalyst bodies 204 and 205 are de-energized. Preheating can be performed. However, even when the outside air temperature is relatively high, all of the above three members may be energized to achieve early combustion.

In the tenth embodiment, one main catalyst 2 is not divided into a plurality of main catalysts 2 and only a part of the main catalyst 2 on the upstream side of the combustion air is electrically conductive. The catalyst may be an acidic catalyst. Further, similarly to 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 carried on both conductive catalysts 204 and 205 is
The catalyst carrying amount of the conductive catalyst body 204 on the upstream side is large,
The catalyst carrying amount of the conductive catalyst 205 on the downstream side may be reduced. (Eleventh Embodiment) FIG. 17 shows an eleventh embodiment. In the first embodiment shown in FIG. 1, the heat exchange between the high-temperature exhaust gas (combustion gas) and the heat medium (for example, water) is performed. The exchanger is integrated into the catalytic combustion device in a compact configuration.

In FIG. 17, a heat exchanger 40 for exchanging heat between a high-temperature exhaust gas and a heat medium includes a combustion cylinder 4 and an upper end plate 2.
0 and on the outer peripheral side of the supply path 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 disposed at one end of the spiral passage 44 and is fixed to the outer cylinder 41. Further, an outlet pipe 47 for the heat medium is arranged at the other end of the spiral passage 44 (a position 180 ° symmetrical in the circumferential direction of the outer cylinder 41), and is fixed to the outer cylinder 41. In addition, coil 4
Reference numeral 3 denotes a hollow pipe which is formed by spirally bending a hollow pipe. The inlet 43a of the coil 43 is joined to the spiral passage 44 immediately after the portion where the inlet pipe 46 is provided, and the heat medium from the inlet pipe 46 is formed. Flows into the passage 44 and at the same time the coil 43
Is also allowed to flow into the inlet portion 43a.

The outlet 43b of the coil 43 is joined to a portion of the spiral passage 44 that is close to the outlet pipe 47 so that the heat medium flowing out of the outlet 43b passes through the passage 4b.
After joining with the heat medium in 4, it flows to the outlet pipe 47 side. That is, the heat medium flows in the coil 43 and the spiral passage 44 in parallel. Also, the inner cylinder 42
On the inner peripheral side, flat fins 48 are arranged at minute intervals (for example,
About 4.5mm), many are arranged radially through
It is integrally joined to the inner peripheral wall of the inner cylinder 42.

Each member 41 to 4 of the above-described heat exchanger 40
Each of 3, 45 to 48 is preferably formed of aluminum from the viewpoint of thermal conductivity, and each joint is joined by, for example, brazing. Further, as the heat medium, in this example, an antifreeze whose freezing temperature is lowered to about −30 ° C. is used. However, water or air may be used as the heat medium according to the use form of the combustion device. .

The heat medium flowing out of the outlet pipe 47 is pressure-fed by a hot water pump (not shown) to a heater core (heating heat exchanger) installed in an air passage of the vehicle heating device, and blown by a blower in the heater core. The heated air and the heat medium exchange heat to heat the blown air, and the heated hot air is blown into the vehicle interior. 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 the present embodiment, the heat exchanger 4
Along with the installation of “0”, the intake cylinder 50 is integrally formed at the center of the upper end plate 20, and the intake cylinder 50 is arranged to extend inside the center of the coil 43. One end (upper end in FIG. 17) of the intake cylinder 50 is closed by a lid 51,
An air inlet 8 is provided on the lid 51, and combustion air from the air inlet 8 is introduced into the intake cylinder 50.

At the other end (lower end in FIG. 17) of the intake cylinder 50, a rectifying plate 52 having a number of small holes formed therein is provided.
While 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. A fuel pipe 53 formed on the 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 in the eleventh embodiment will be described. The spiral pipe 44 of the heat exchanger 40 is connected to the inlet pipe 46.
A part of the heat medium (antifreeze) flowing into the inside flows through the coil 43, and the remaining heat medium (antifreeze) flows through 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 the exhaust gas (combustion gas) on the outer surface of the fuel cell 3, and the gas is heated to a high temperature. Then, the flows of the two heat mediums merge on the upstream side of the outlet pipe 47 and flow out of the outlet pipe 47 to the outside.

The heating capacity is controlled, for example, by increasing or decreasing the amount of combustion according to the temperature detected by the heat medium temperature detector 49. With the above configuration and operation, the highly efficient heat exchanger 40 having a compact configuration can be integrated with the catalytic combustion device. In addition, in the flame combustion, carbon generated during combustion generally adheres to the gap between the fins 48 and fills the gap between the fins 48, which tends to cause a decrease in heat exchange efficiency. In the catalytic combustion according to the invention,
Since almost no carbon is generated, the interval 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 other points are the same as the first embodiment. (Twelfth Embodiment) FIG. 18 shows a twelfth embodiment in which the coil 43 is deleted from the eleventh embodiment of FIG. This reduces the heat exchange efficiency between the heat medium and the exhaust gas, but has the advantage that the configuration of the heat exchanger 40 can be simplified. (Thirteenth Embodiment) FIG. 19 shows a thirteenth embodiment. In the eleventh and twelfth embodiments of FIGS. 17 and 18, a heat exchanger 40 for exchanging heat between a high-temperature exhaust gas and a heat medium is used.
Is disposed between the combustion cylinder 4 and the upper end plate 20, but in the thirteenth embodiment, the heat exchanger 40 is disposed on the outer peripheral side of the catalyst bodies 2, 3.

That is, in the thirteenth embodiment, the heat exchanger 4
0 is disposed on the outer peripheral side of the catalyst body 2, 3, and radial fins 48 are disposed on the outer peripheral side of the combustion cylinder 4 through a minute gap, and the inner cylinder disposed on the outer peripheral side of the radial fins 48. A spiral passage 44 is formed between the outer cylinder 41 and the spiral partition plate 45 by a spiral partition plate 45. Therefore, the outer cylinder 4
1 also functions as the cover 19 in the first to twelfth embodiments.

Further, a bottom plate 42a of the inner cylinder 42 is disposed outside the premixing 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.
Is installed. Therefore, the exhaust gas flowing out of the main catalyst body 2 makes a U-turn in the exhaust gas chamber 9 and
19, goes downward in FIG. 19, and exits through the exhaust gas outlet 16.

According to the thirteenth embodiment, the exhaust gas flows to 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 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. 3 is easy to maintain in a high temperature state,
Good catalytic combustion can be maintained.

There is also 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 at the same time. Further, in the thirteenth embodiment, the eleventh and twelfth
Compared to the configuration of the heat exchanger integrated according to the embodiment, the combustion device has a laterally long shape in which the axial size of the combustion device is small, so that the mountability to the vehicle is improved.

In the thirteenth embodiment, the spiral coil 43 in the eleventh embodiment is omitted.
As in the first embodiment, the spiral coil 43 may be arranged on the inner peripheral side of the fin 48, as a matter of course. (Other Embodiments) In each of the above-described embodiments, in order to activate the catalyst early, the catalyst body is replaced with the starting catalyst body 3.
And the main catalyst 2, and these two catalysts 2, 3
A single catalyst may be used.

In the time charts of FIGS. 3 and 14, after the operation switch 22 is turned on, a predetermined time t1 + t2
The increase in the amount of combustion performed after the passage of course may be continuous or stepwise. Also, in FIG. 3, the post-purge operation time is specified by the timer means as the predetermined time t4. However, instead of using this time, the temperature detected by the temperature detector 17 is changed to the predetermined temperature after the post-purge operation starts. When the temperature decreases to a lower level, the post-purge operation may be stopped.

In the first embodiment and the like, the fuel nozzle 10 is of a type that opens and sprays fuel when the fuel supply pressure from the fuel pump 12 exceeds a predetermined pressure. The nozzle 10 may be a two-fluid spray type that simultaneously sprays fuel and air. Also, an ultrasonic nozzle for atomizing liquid fuel with 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.

Here, when a well-known electromagnetic injector for a vehicle or the like is used as the fuel nozzle 10, the amount of fuel supplied 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. In the fifth and sixth embodiments, etc., the fuel absorber 27 is provided in the exhaust mixing cylinder 5,
The fuel absorber 27 may be eliminated, and a spiral groove or the like may be formed on the inner wall surface of the exhaust mixing cylinder 5, and the fuel holding effect may be enhanced in the groove to improve the evaporability.

In the present invention, the fuel is not limited to a liquid fuel such as kerosene but may be a gaseous fuel such as natural gas.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.

FIG. 2 is an electric 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 longitudinal sectional view showing a second embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing a third embodiment of the present invention.

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

FIG. 7 is a longitudinal 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 a fifth embodiment, and FIG. 8B is a top view of a first plate-shaped member of the fuel nozzle.

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

FIG. 10A is a longitudinal 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 longitudinal sectional view showing a seventh embodiment of the present invention.

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

FIG. 13A is a longitudinal 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 longitudinal sectional view showing a ninth embodiment of the present invention.

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

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

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

FIG. 19 is a longitudinal 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 mixing cylinder, 6 ... Primary nozzle, 6a ... Throttle section, 6b ...
Secondary nozzle, 7 ... Air pump, 9 ... Exhaust gas chamber, 10 ...
Fuel nozzle, 12: fuel pump, 13: premix chamber, 14
... Fuel absorber, 15 ... Electric heater, 19 ... Insulation material, 24
... an auxiliary electric heater, 27 ... a fuel absorber, 28 ... a deflection plate,
30: Conductive starting catalyst, 40: Heat exchanger.

Claims (20)

[Claims] 1. A fuel supply means (10, 1) for supplying fuel.
2) and combustion air supply means (7, 8) for supplying combustion air
A catalyst (2, 3) for catalytically burning a mixture of the fuel and the combustion air; and a combustion tube (4) containing the catalyst (2, 3). 3) has a through hole (2b,
3b). The fuel supply means (10, 12) and the combustion air supply means (7, 3) are formed at one end of the catalyst body (2, 3).
8), a premixing chamber (13) for forming an air-fuel mixture of the fuel and the combustion air is provided at the other end of the catalyst body (2, 3), From one end 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 mixture is turned in the premixing chamber (13),
The inside of the catalyst (2, 3) flows from the other end to one end, and a part of the exhaust gas after passing through the catalyst at one end of the catalyst (2, 3) is used as the combustion air. A catalytic combustion device characterized by refluxing into combustion air from a supply means (7). 2. An exhaust mixing cylinder (2) for mixing the combustion air and a part of the exhaust gas after passing through the catalyst body into a through hole (2b, 3b) at the center of the catalyst body (2, 3). The catalytic combustion device according to claim 1, wherein (5) is provided. 3. A primary nozzle (6) having a throttle (6a) for narrowing a flow of the combustion air is provided adjacent to one end of the catalyst body (2, 3). 3. A part of the exhaust gas after passing through the catalyst body (2, 3) is recirculated into the combustion air by a pressure reducing action by the part (6a). Catalytic combustion equipment. 4. The throttle section (6a) is disposed at the center of the exhaust mixing cylinder (5), and the exhaust gas after passing through the catalyst body (2, 3) from the outer peripheral side of the throttle section (6a). The catalytic combustion device according to claim 3, wherein a part of the gas is recirculated into the combustion air. 5. A ring-shaped secondary nozzle (6b) on the outer peripheral side of the throttle section (6a) for recirculating a part of exhaust gas after passing through the catalyst body (2, 3) into the combustion air. The catalytic combustion device according to claim 4, further comprising: 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 body (2, 3) is divided into a plurality in the axial direction, and the plurality of catalyst bodies (2, 3) become closer to the premixing chamber (13) side. 7. The catalytic combustion apparatus according to claim 1, wherein the amount of the catalyst carried is increased. 8. An exhaust gas chamber (9) filled with exhaust gas after passing through the catalyst body (2, 3) is formed at one end side of the 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 equipment. 9. The method according to claim 1, wherein a heat insulating material is arranged around the premixing chamber and the catalyst body. A catalytic combustion device according to any of the preceding claims. 10. The fuel is a liquid fuel, and the fuel supply means includes a fuel nozzle (10) having a characteristic that a fuel spray angle increases with an increase in the liquid fuel flow rate. Is the fuel nozzle (10)
The fuel spray angle sprayed from the fuel nozzle (10) is increased to direct the spray fuel from the fuel nozzle (10) toward the inner wall surface of the through hole (2b, 3b) of the catalyst body (2, 3). The catalytic combustion device according to any one of claims 1 to 9, wherein 11. The fuel is a liquid fuel, and a liquid fuel supplied from the fuel supply means (10, 12) is provided on an inner wall surface of a through hole (2b, 3b) of the catalyst body (2, 3). A deflecting plate (28) for deflecting the flow, and when the liquid fuel flow rate is large, the deflecting plate (28) deflects the fuel supplied from the fuel supply means (10, 12) to the catalyst (2, 3). The catalytic combustion device according to any one of claims 1 to 9, wherein the device is directed toward an inner wall surface of the through hole (2b, 3b). 12. The through-hole (2) in the catalyst body (2, 3).
The catalytic combustion device according to claim 10 or 11, wherein a fuel absorber (27) for absorbing and evaporating the supplied liquid fuel is provided on the inner wall surface of (b) or (3b). 13. An electric heater (15) is arranged in the premixing chamber (13).
3. The catalytic combustion device according to any one of 2. 14. When the combustion operation is started, the electric heater (15) is energized, 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. When the exhaust gas temperature after passing through the medium (2, 3) reaches the first predetermined temperature (T1), the supply amounts of the fuel and the combustion air are increased continuously or stepwise, and thereafter, the catalyst body is further increased. (2, 3) When the temperature of the exhaust gas after passing the gas reaches a second predetermined temperature (T2) higher than the first predetermined temperature (T1), the power supply to the electric heater (15) is stopped. Claim 1
4. The catalytic combustion device according to 3. 15. An auxiliary electric heater (24) for heating combustion air supplied from said combustion air supply means (7).
15. The catalytic combustion device according to claim 14, wherein when the electric heater (15) is energized, the auxiliary electric heater (24) is also energized. 16. A starting catalyst body (30) having conductivity is arranged at a position closer to the premixing chamber (13) side than the ring-shaped catalyst body (2). The catalyst body (30) is configured to be capable of being energized from the outside, and by energizing the starting catalyst body (30), the starting catalyst body (30) itself generates heat as an electric resistor. 13. The catalytic combustion device according to any one of 1 to 12. 17. When the combustion operation is started, electricity is supplied to the conductive starting catalyst body (30) and a predetermined time (t
1) After the lapse of time, the supply of the fuel and the combustion air is started in a small amount. Thereafter, the exhaust gas temperature after passing through the ring-shaped catalyst body (2) and the starting catalyst body (30) becomes the first temperature. At the point in time when the temperature reaches the predetermined temperature (T1), the supply amounts of the fuel and the combustion air are increased continuously or stepwise, and then the exhaust gas temperature after passing through both of the catalyst bodies (2, 30) is reduced to the first temperature. 17. The catalytic combustion device according to claim 16, wherein the power supply to the starting catalyst body (30) is stopped at a time point when the temperature reaches a second predetermined temperature (T2) higher than the predetermined temperature (T1). 18. The ring-shaped catalyst body (2) has conductivity and is configured to be able to conduct electricity from the outside, and when the starting catalyst body (30) is energized, the ring-shaped catalyst body (2) is electrically conductive. 2), the both catalysts (2, 3)
The catalytic combustion device according to claim 17, wherein 0) generates heat as an electric resistor. 19. A heating medium for heating and a catalyst (2, 3, 3) at one end of the catalyst (2, 3, 30).
0) The catalyst according to any one of claims 1 to 18, further comprising a heat exchanger (40) for exchanging heat with the exhaust gas having passed therethrough and heating a heating medium for heating. Combustion equipment. 20. Heating medium for heating and heat exchange between the exhaust gas after passing through the catalyst body (2, 3, 30) are provided on the outer peripheral side of the combustion tube (4). 19. The catalytic combustion device according to claim 1, further comprising a heat exchanger (40) for heating the catalyst.