DE2713274A1 - IC engine catalytic converter unit - producing gaseous fuel from unusable liq. hydrocarbons by using linked converters - Google Patents

Abstract

The catalytic converter unit for producing gaseous IC engine fuel from fluid hydrocarbons, comprises a number of converter units, working on the endothermic principle. These (4a-d) are arranged in parallel at the outlet from an exhaust gas mixing chamber (6) on the engine. Throttle valve (5a, b, c) control the gas flow into all but one (4d) of the converters; there are also throttle valves (10a, b, c) in all but one (8d) of the liquid-supply lines (8a-d) to the converters. Pressure variation in the engine inlet manifold is used to control these valves so that gas and liquid flow is to one converter only at idling, the others being brought in progressively until all are in use at full load. Gaseous fuel discharge is through a common line (9). Gas turbulence at exit from converters in use causes reverse flow into any that are shut off, pre-heating the latter so that they are ready to function properly when required.

Description

description

The present invention relates to a catalytic converter for an automotive internal combustion engine or the like using a liquid hydrocarbon fuel into a hydrogen-rich, gaseous fuel for combustion in the engine combustion chamber converts, with only one of the four catalytic converters ending during all phases of engine operation exposed to hot exhaust gases and charged with liquid fuel while the other three converters one after the other by opening the throttle valve in Depending on the increase in vacuum in the venturi area of the carburetor, which Vacuum is characteristic of the volume of air supplied, the exhaust gases get abandoned.

The present invention relates to an internal combustion engine, which is designed for operation with a hydrogen-rich, gaseous fuel and in particular to an improved catalyst device that incorporates a liquid Hydrocarbon fuel, such as methanol, into one rich in hydrogen and carbon monoxide Gas converts.

As is well known, it is in the interest of environmental protection and the protection of the dwindling natural deposits of crude oil desirable, to develop an internal combustion engine, especially for motor vehicles, that only produces little or no air pollution and uses a fuel, such as methanol (or any similar Alcohol or other Hydrocarbon) is operated in any amount at very low cost by bacterial decomposition of vegetable matter and / or any other can be produced in a suitable manner.

To this end, it has been proposed an internal combustion engine to equip with a catalytic converter of normally unusable hydrocarbon fuels into hydrogen and carbon monoxide either via a partial oxidation reaction or converts to an endothermic catalytic reaction, the latter usually being the normally unused thermal energy of the exhaust gases as a source for the Heat of reaction used. The endothermic reaction points towards the partial oxidation reaction various advantages in that the equipment for the former is more compact, does not require the introduction of excessive amounts of air, is easier to implement, no fuel swirl and combustion devices or air heater is required and is thermodynamically more effective, with the waste heat is returned in the form of the converted gas (as explained later will be).

However, there is also a notable disadvantage, which is that the catalyst bed does not always reach a sufficiently high temperature and / or which allows the liquid hydrocarbon fuel to rapidly convert to H2 and CO is converted. The reason for this is that the interpretation of the catalyst bed due to the maximum fuel consumption to be expected in the engine is done.

In order to achieve this maximum fuel consumption of the engine, is a certain amount of catalyst is necessary; at low engine load and low However, the number of revolutions is the amount of heat contained in the exhaust gases for uniform Insufficient heating of the entire catalyst mass, so that the conversion rate at which the liquid hydrocarbon fuel through the catalyst within the Reactor vessel is implemented is very low. This has become totally inadequate Engine performance, especially under power delivery conditions and when fast Responding to changes in performance requirements, guided. For this reason the engine is not usable in motor vehicles in which the performance requirements change to a large extent depending on road and traffic conditions.

The present invention attempts to address the above-mentioned disadvantages to be overcome by having a large number of smaller catalytic converters is provided and arranged to be sequentially exposed to the flow of exhaust gas and with liquid hydrocarbon fuel for catalytic conversion in their Inside can be acted upon.

The number of converters exposed to exhaust gases and the in The amount of fuel they convert depends on the performance requirement controlled by the engine.

The main object of the present invention is to provide a catalytic converter for an internal combustion engine for converting a liquid Hydrocarbon fuel into a hydrogen-rich, gaseous fuel provide in which during low load operation or during idle of the engine only part of the total amount of catalyst expelled from the engine Exhaust gases is exposed and in which only this heated area with a liquid fuel is applied for the purpose of its conversion, so that this heated area has a high conversion efficiency. Another job is to provide such a catalytic converter in which the catalyst is distributed to a large number of converters, which can optionally be used for the exhaust gas flow could be exposed and so depending on the amount contained in the exhaust gases Amount of heat can be heated. Another task is to make a possible simple construction to provide for this catalytic converter and to use it with to equip a control system that only simple electronic and mechanical Requires parts and is therefore easy and simple to install and maintain.

Finally, one task is to make such a catalytic Provide converters that use a liquid hydrocarbon fuel during all phases of engine operation converted in sufficient quantities into a hydrogen-rich, gaseous fuel.

According to the invention, these tasks are described in the characterizing part of the main claim as well as the subclaims solved.

Further tasks, solutions and advantages of the invention result from the following description of an exemplary embodiment in conjunction with the attached drawings; 1 shows a schematic plan view on an internal combustion engine, which is equipped with a catalytic converter device for Converting a liquid hydrocarbon fuel to a hydrogen-rich one, gaseous fuel is equipped; and FIG. 2 is a schematic view of one Part of the control system used in the engine of Figure 1 to control flow direction the exhaust gases via or the fuel flow through the plurality of in the mentioned catalytic converter device provided converter.

According to FIG. 1, the internal combustion engine 1 is equipped with a catalytic Converter device equipped loo, which is housed in an exhaust duct 3 which is divided into four parallel branches 3a, 3b, 3c and 3d or in some other flow path is divided, with four catalytic converters 4a, 4b, 4c and 4d in these parallel branches are arranged.

Upstream of all of these but one catalytic converter is a variety of control or regulating valves 5a, 5b and 5c, which in this Case shown as throttle valves are arranged. The exhaust duct is between the exhaust ports and formed in the side wall of the engine block the upstream areas of the catalytic converters as more uniform Formed exhaust duct, which is generally provided with the reference numeral 6 and which allows a mixing of the gases from all exhaust openings, and makes it possible that these exhaust gases flow exclusively through the one catalytic converter 4d, so as indicated by the arrows when the control valves 5a, 5b and 5c the Fluid connection between the exhaust ports and the exhaust ducts 3a, 3b or 3c, as shown in Fig. 1, shut off.

A liquid hydrocarbon fuel is drawn from a storage tank (not shown) the catalytic converters 4a, 4b, 4c and 4d via the liquid fuel supply lines 8a, 8b, 8c and 8d, respectively. In the supply lines 8a, 8b and 8c are open / closed - Arranged valves loa, lob and loc, which either interrupt the flow of fuel or enable. It should be noted that in the liquid fuel supply line 8d no valve is arranged and the catalytic converter 4d during all engine operating phases is constantly supplied with fuel. Likewise is upstream of the catalytic Converter 4d no control valve is provided, so that this converter is the only one during all engine operating phases converts liquid fuel. As can be seen in the figure, the liquid fuel supply lines are on the downstream ends of the catalytic converters interconnected. They are also at the upstream ends of the catalytic converters connected to a unitary line 9, the from these catalytic converters discharged, converted gas is fed to the engine for combustion.

From Fig. 1 it can be seen that during idling or low load operation preferably only the catalytic converter 4d charged with fuel and the Exhaust gas flow is exposed, causing the catalyst contained in the converter is heated sufficiently to a temperature at which the liquid hydrocarbon fuel is converted quickly and effectively. These exhaust gases flow after passage through the parallel branch 3d then through the exhaust pipe, as indicated by the arrows is shown. However, these exhaust gases will inevitably enter the others as well Swirl in parallel branches 3a, 3b and 3c and the catalytic converter 4a, 4b and heat 4c. The exhaust gases are indeed after they have passed the catalytic Converter 4d no longer have a high temperature, but they are still sufficient be hot in order to partially heat the converters that are temporarily unused, as there is no Fuel is present, which in these converters is a heat-absorbing, endothermic Subject to reaction, If when operating the engine the power requirements increase, the control valves 5c, Sb and 5a are gradually opened so that the exhaust gases through one, then through the second, then through the third and finally flow through all parallel branches; the on / off valves are activated at the same time loc, lob and loa gradually open synchronously with the corresponding control valves, so that as the exhaust gases gradually pass through the catalytic converter 4c, 4b and 4a flow, the liquid fuel can flow through these converters.

It follows that a gradual heating of the catalytic Converter gradually increases the volume of the gas converted in these converters elevated. The amount of the catalyst 7 in the catalytic converter 4d is preferable chosen so that while the engine is idling there is still enough heat in the Exhaust gases are included in order to bring the amount of catalyst to a temperature which achieves rapid conversion of the liquid hydrocarbon fuel will and similar to the traditional arrangements the rate at which fuel is fed into the catalytic converter 4d, in view of the power requirement of the engine is controlled, i.e. less fuel goes to the catalytic converter 4d is introduced when idling than when driving the motor vehicle with lower Speed. The arrangement is preferably designed so that when reached of the conversion capacity of the catalytic converter 4d, the control valve 5c is opened to enable that the increased volume of exhaust gases is split between the two parallel branches and allows the fuel will flow into both converters.

In Fig. 2 is a control system for the catalytic converter device shown. It is here for the sake of simplicity and ease of explanation only part of the overall system is shown.

The reference numeral 14 denotes a venturi region of a carburetor 2, which can consume the converted gas instead of gasoline. Downstream of A throttle valve 26 is arranged in this venturi region 14, which in FIG Position is shown. Connected to the carburetor 2 and arranged so that they the vacuum of the Venturi area, which Va = m characterizing the in the combustion chamber the amount of air introduced by the engine is exposed, is a conduit 16 which is fluid is connected to the interior of a vacuum canister 18 of a vacuum can 12. As in As shown in the figure, a spring is arranged to support the diaphragm 17 in the direction of the atmospheric pressure chamber (no reference number). With This diaphragm 17 is connected to a rod 21 which is movable with the diaphragm is. At the end of the rod there is a step switch 20 which has several stepped Areas (without reference numerals) for step-by-step engagement with a large number of microswitches 19a, 19b and 19c. In this figure only the microswitch 19a is with connected to the connected facility, but it goes without saying that actually a similar structure in relation to the other two microswitches is used.

The microswitch 19a is in the figure with an electromagnetic Valve 29a connected, which is provided for controlling the line 27a in this line is, which is arranged so that when a corresponding signal is received from Microswitch 19a the connection between one in the carburetor below the throttle valve 26 lying area and a vacuum chamber of the vacuum can 13a close or interrupt can and via a line 30a a connection between the atmosphere and the Can produce vacuum chamber 25a. The vacuum box 13a is connected via a rod 24a a lever 23a connected to the simultaneous rotation with the valve rod of the control valve 5a is connected.

With the micro switch 19a, the on / off valve loa is also in Connection, which, as already described above, is provided to the passage of the liquid hydrocarbon fuel either to enable or to prevent. In Fig. 2 it is shown in the open position, it the flow of the Allows fuel into the catalytic converter 4a via line 8a. As is shown, the converted gas is from the upstream end of the catalytic converter 4a led out via line 9.

If the vacuum in the venturi area of the carburetor increases during operation, the diaphragm 17 of the vacuum can 12 bulges towards the vacuum chamber. Included the step switch is 20 so that he moved the microswitch 19a, 19b and 19c touched one after the other. The step switch 20 is designed in such a way that that, during its displacement movement, it first presses microswitch 19c, then the microswitch 19b and finally touched microswitch 19a. If so the step switch 20 the Touches microswitch 19c, a signal is sent to the associated electromagnetic Valves 29c and loc released. Atmospheric pressure can enter the vacuum chamber of the vacuum motor 13c, whereby the spring operates the rod 24c in such a way that that the control valve 5c is moved into its open position via the lever 23c, so that the exhaust gases can sweep away via the catalytic converter 4c. At the same time, liquid hydrocarbon fuel becomes its conversion into fed into the catalytic converter. If then the vacuum continues to rise and the diaphragm bends even further, the step switch 20 touches the next microswitch 19b, so that the above-described process is repeated is operated, i.e. the electromagnetic valves 29b and lob and the control valve 5b is opened. When finally the diaphragm extends to its extreme position sags, the last microswitch 19a is touched by the step switch 20. The throttle valve is in one or almost in a wide open position are located. The situation shown in Fig. 2 arises when all microswitches touched by the step switch 20 and thereby all control valves are opened.

If, conversely, the throttle valve in the carburetor is closed will and the vacuum in the venturi area decreases and the vacuum downstream of the throttle valve increases, the diaphragm of the vacuum can 12 bends in the opposite direction by, so that the steps of the tap changer 20 one after the other out of engagement with the microswitches come. To the extent that the signals from the microswitches fail, the electromagnetic valves close the fuel supply to the catalytic ones Converters and reconnect the associated vacuum sockets with the downstream located area of the carburetor, whereby the vacuum existing in this area on the vacuum chambers of the vacuum cans is transferred and the connected to it Control valves are brought into a closed position so that the exhaust gas flow is prevented via the corresponding catalytic converter.

Although this is not shown in the figures, it is according to the present invention possible to have a heat sensor in the exhaust pipe, which is located downstream located end of the converter device is intended to be attached to the low Temperature conditions should generate a signal and e.g. with an electromagnetic Valve similar to that in lines 27a, 27b and 27c (only 27a being shown in FIG valves provided. This valve could simply be in the line 16 can be provided to the existing in the vacuum chamber 18 vacuum to vent if and when the temperature of the exhaust gases to an undesirably low Level drops. This causes the diaphragm to move so that the tap changer 20 mlt one or more microswitches disengaged, whereby one or more of the control valves are closed. In this way the limited amount of available heat would then be reduced to a smaller one Number of catalytic converters passed, which are then kept at one temperature which can efficiently convert the liquid hydrocarbon fuel is still guaranteed. Otherwise there is a drastic reduction in conversion efficiency inevitable, which would occur when the temperature of all catalytic Converter drops below a desired level.

According to the present invention, it is also possible to serve the catalytic converter 7 contained in each of the converters is to be provided in such a way that that they are each different. For example is the amount of in the converter 4d contained catalyst is preferably dimensioned so that it is idling the internal combustion engine can be adequately heated by the exhaust gases while the quantities in the converters 4c, 4b and 4a should each be greater than that in each case previous amount, which makes the production of the converted gas more uniform is designed. As described above, it is used to balance production on converted gas also possible to convert the liquid hydrocarbon fuel into the converter is increasingly dependent on such a parameter as the degree of opening of the throttle valve.

If this is also shown and described in the exemplary embodiment was, of course, the invention is not on four catalytic Converter limited. Likewise, the illustrated control system is not on use limited, albeit, by throttle valves for controlling exhaust gas flow the illustrated embodiment because of its simplicity and its compact design is preferred. Any number of converters can be used on a case-by-case basis as well as the different motor vehicles can serve different purposes.

It is also possible that the common channel 6 as a thermal Reactor can serve and is designed as such, the toxic emissions, such as HC and CO are eliminated and at the same time heat is generated that is necessary to convert of the liquid hydrocarbon fuel is usable. This is how the motor equipped with the converter device according to the present invention The hydrogen-rich fuel in the engine combustion chambers is extremely clean burned so that NOx emissions are effectively eliminated, and there the methanol can be made so that it is sulfur-free, malodorous and / or Corrosive sulfur emissions avoided, thereby reducing when the catalytic converter built into the exhaust system of the engine, all sulfur related standing problems are turned off.

Claims (7)

Catalytic converter for an automotive internal combustion engine or the like Claims 0 Catalytic converter for a motor vehicle internal combustion engine or the like, which converts a liquid hydrocarbon fuel into a hydrogen-rich, converts gaseous fuel for combustion in the engine chambers, the at The hot combustion or exhaust gases produced during combustion via the in the engine exhaust ducts provided at a suitable point are marked through an exhaust duct (3) connected to the engine (1), which has a fluid connection creates to the exhaust ports; a variety of within the Exhaust duct (3) arranged passages (3a, 3b, 3c, 3d) which are arranged so that they prevent the passage of the exhaust gases emitted from the exhaust ports of the engine to an exhaust pipe, fluidly at the most downstream located area of the exhaust duct (3) is connected; one inside the exhaust duct (3) formed uniform exhaust duct (6), the fluid-wise the upstream located areas of the plurality of passages (3a, 3b, 3c, 3d) with the exhaust openings the motor (1) connects; a variety of catalytic converters (4a, 4b, 4c, 4d), each of which is fluidly distributed to one of the passages (3a, 3b, 3c, 3d) and is arranged so that it can be heated when the hot gases flow through it; one Multiplicity of valves (5a, 5b, 5c, 5d), which upstream of all but one, catalytic converters (4a, 4b, 4c, 4d) provided and so arranged and designed are that they have a first normal or open position, which it the hot exhaust gases allows to wipe over the catalytic converters and a second closed position occupy the hot exhaust gases flowing past the catalytic converters (4a, 4b, 4c, 4d) prevented; a plurality of first control devices (13, 29, 23), each of which is operatively connected to a control valve (5a, 5b, 5c) is and can be operated so that they are these control valves from a first moves normally open position to a second closed position; a Fuel supply system consisting of a large number of fuel supply lines (8a, 8b, 8c, 8d), each of which feeds fuel into a catalytic converter (4a, 4b, 4c, 4d) and all but one of which has an on / off valve (loa, lob, loc) have; a line (9) for introducing the in each catalytic converter (4a, 4b, 4c, 4d) by converting liquid hydrocarbon fuel using the converted gas produced by the catalysts contained in these converters from each catalytic converter (4a, 4b, 4c, 4d) into the engine (1), from where it is after its combustion through the exhaust ports into the unified exhaust duct (6) is ejected; a second, from the volume of those fed into the engine combustion chambers Air-controlled control device (12,19,20), which are designed and arranged is that it is optionally a plurality of first control devices (13a, 13b, 13c) enables a large number of control valves (5a, 5b, 5c) to be opened and so on the flow of hot exhaust gases past the downstream of these control valves (5a, 5b, 5c) arranged catalytic converters (4a, 4b, 4c) allows, and that they can optionally introduce liquid fuel into the in this way heated catalytic converter (4a, 4b, 4c) by opening the on / off valves (loa, lob, loc) depending on the increase in the allows introduced air; the aforesaid arrangement operating so that through all phases of engine operation away at least one of the catalytic converters (4a, 4b, 4c, 4d) by flowing past the hot exhaust gases are heated and exposed to liquid hydrocarbon fuel while the other passages are activated one after the other by pressing the first (13a, 13b, 13c) and second (12) control devices depending on the rise in the engine combustion chambers introduced volume of air are to be opened and the fuel in the catalytic Converters (4a, 4b, 4c) one after the other and in each case according to their application is introduced with hot exhaust gases. 2. Catalytic converter according to claim 1, wherein the motor with a Carburetor is equipped with the combustible charges from air and the hydrogen-rich, gaseous Fuel can be produced, with this gasifier having a venturi area and a has a throttle valve arranged downstream thereof, characterized in that that each of the several first control devices has a vacuum box (13a, 13b, 13c) with an effective diaphragm (28a, 28b, 28c) which this vacuum box in a Subdivided into a vacuum chamber and an atmospheric pressure chamber, the diaphragm (28a, 28b, 28c) by means of a spring acting in the vacuum chamber in the direction of the atmospheric pressure chamber is biased; an electromagnetic valve (29a, 29b, 29c), which is inserted into a line (27a, 27b, 27c) which connects the vacuum chamber (25a, 25b, 25c) the vacuum box (13a, 13b, 13c) with the downstream of the throttle valve (26) arranged area of the carburetor (2) connects, this electromagnetic Valve (29a, 29b, 29c) upon receipt of a signal from the second control device (12) the connection between the carburetor (2) and the vacuum chamber (25a, 25b, 25c) interrupt and a connection between the atmosphere and the vacuum chamber (25a, 25b, 25c) can produce; and lever means comprising the diaphragm (28a, 28b, 28c) and the control valve (5a, 5b, 5c) connects, this lever device this control valve (5a, 5b, 5c) from a first normally open position can rotate into a second closed position when the diaphragm (28a, 28b, 28c) bulges against the bias of the spring force. 3. Catalytic converter according to claim 1, characterized in that that the second control device consists of a vacuum box (12) with one in it effective diaphragm (17), which the can (12) in a vacuum chamber (18) and a Atmospheric pressure chamber divided, the diaphragm (17) by a spring in Towards the atmospheric pressure chamber and the vacuum chamber (12) Connected via a line (16) to the venturi area (14) of the carburetor (2) is, so that the vacuum box (12) from that prevailing in the venturi area (14) vacuum is operated; a step switch (20) connected to the diaphragm (17) for the purpose its movement is in functional connection and that with at least one graduated Area is provided; a plurality of microswitches (19a, 19b, 19c) so are arranged and designed that they are sequentially stepped with at least one Area of the tap changer (20) can be brought into engagement when it is through the Movement or bulge of the diaphragm (17) is displaced and a signal is generated generated, and that each microswitch (19a, 19b, 19c) with an electro-magnetic Valve (29a, 29b, 29c) which is arranged in a line connected to the vacuum box (13a, 13b, 13c) of the first control device is in connection, as well as with a in the fuel supply line (8a, 8b, 8c) arranged on / off valve (1oa, lob, loc) is electrically connected, so that when it comes into contact with the tap changer (20) the microswitch (19a, 19b, 19c) generates a signal that the electromagnetic Valve (29a, 29b, 29c) for connecting the vacuum chamber (25a, 25b, 25c) of the first Control device caused by the atmosphere, whereby the control valve (5a, 5b, 5c) moved into its first, the so-called open position, and the on / off valve (loa, lob, loc) is caused to open so that it is the liquid hydrocarbon fuel is possible in the downstream of the control valves with respect to the exhaust gases (5a, 5b, 5c) located catalytic converter (4a, 4b, 4c) to flow in, wherein these control valves (5a, 5b, 5c) at the same time by the same signal be opened. 4. Catalytic converter according to claim 1, characterized in that that this additionally has a heat sensor which is designed and arranged in such a way is that it follows the flow of exhaust gases in the downstream area of the Exhaust duct is exposed and a temperature in the exhaust gases characterizing Generates signal that if it is below a predetermined level, the or interrupts the signals generated by the microswitches and at least one the control valves (5a, 5b, 5c; loa, lob, loc) closes and the fuel supply in the catalytic converter or converters (4a, 4b, 4c) downstream of this at least one control valve (5a, 5b, 5c) are arranged, interrupts. 5. Catalytic converter according to claim 2, characterized in that that the lever device consists of a rod (24a, 24b, 24c) connected to the diaphragm (28a, 28b, 28c) of the vacuum box (13a, 13b, 13c) of the first control device is, and consists of a lever (23a, 23b, 23c) which is connected to the valve rod of the control valve (Sa, Sb, 5c) for their simultaneous displacement and with the rod (24a, 24b, 24c) is connected via which the movement of the diaphragm (28a, 28b, 28c) is transmitted will. 6. Catalytic converter according to claim 1, characterized in that that the at least one catalytic converter (4d), which during all engine operating phases constantly with the current exposed to hot exhaust gases, an amount of catalyst which is selected so that the during idling in the ejected by the engine the amount of heat contained in hot exhaust gases is sufficient, this Xatalyst mass keep at a sufficient reaction temperature, thereby creating an effective Conversion of the liquid hydrocarbon fuel into a hydrogen-rich one, gaseous fuel is secured. 7. Catalytic converter according to claim 1, characterized in that that the plurality of valve devices (5a, 5b, 5c) consist of butterfly valves consists at the entrance of and / or upstream of the in each of the several Catalytic converters (4a, 4b, 4c) provided through passages are arranged.