CA1125601A - Feed system for introducing water and/or water vapor into suction path of an internal combustion engine - Google Patents
Feed system for introducing water and/or water vapor into suction path of an internal combustion engineInfo
- Publication number
- CA1125601A CA1125601A CA336,903A CA336903A CA1125601A CA 1125601 A CA1125601 A CA 1125601A CA 336903 A CA336903 A CA 336903A CA 1125601 A CA1125601 A CA 1125601A
- Authority
- CA
- Canada
- Prior art keywords
- internal combustion
- combustion engine
- water
- heat exchanger
- feed system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/022—Adding fuel and water emulsion, water or steam
- F02M25/0221—Details of the water supply system, e.g. pumps or arrangement of valves
- F02M25/0225—Water atomisers or mixers, e.g. using ultrasonic waves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/022—Adding fuel and water emulsion, water or steam
- F02M25/0227—Control aspects; Arrangement of sensors; Diagnostics; Actuators
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/022—Adding fuel and water emulsion, water or steam
- F02M25/025—Adding water
- F02M25/028—Adding water into the charge intakes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M25/00—Engine-pertinent apparatus for adding non-fuel substances or small quantities of secondary fuel to combustion-air, main fuel or fuel-air mixture
- F02M25/022—Adding fuel and water emulsion, water or steam
- F02M25/032—Producing and adding steam
- F02M25/035—Producing and adding steam into the charge intakes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Public Health (AREA)
- Water Supply & Treatment (AREA)
- Output Control And Ontrol Of Special Type Engine (AREA)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
- Heat Treatment Of Water, Waste Water Or Sewage (AREA)
Abstract
FEED SYSTEM FOR INTRODUCING WATER AND\OR WATER VAPOR
INTO THE SUCTION PATH OF AN INTERNAL COMBUSTION ENGINE
ABSTRACT OF THE DISCLOSURE
This invention relates to a feed system for introducing water in the liquid and/or vaporous state into the suction path of an internal combustion engine, consisting of a water stock vessel, of a heat exchanger, to one side of which ex-haust gases from the internal combustion engine can be ad-mitted and to the other side of which the water can be ad-mitted, and of the heat barrier upstream of the heat ex-changer, which comprises a metering device for metering the quantity of water, which is to be fed into the suction path, and a control device which controls the metering device as a function of at least one operating parameter of the internal combustion engine.
INTO THE SUCTION PATH OF AN INTERNAL COMBUSTION ENGINE
ABSTRACT OF THE DISCLOSURE
This invention relates to a feed system for introducing water in the liquid and/or vaporous state into the suction path of an internal combustion engine, consisting of a water stock vessel, of a heat exchanger, to one side of which ex-haust gases from the internal combustion engine can be ad-mitted and to the other side of which the water can be ad-mitted, and of the heat barrier upstream of the heat ex-changer, which comprises a metering device for metering the quantity of water, which is to be fed into the suction path, and a control device which controls the metering device as a function of at least one operating parameter of the internal combustion engine.
Description
2~
The invention relates to a feed system for intro~
ducing water in the liquid and/or vaporous state into the suction path o~ an internal combustion engine, oonsist-ing o~ a water stock vessel, of a heat exchanger, to one side o~ which exhaust gases ~rom ~he internal combustion engine can be admitted and to the other side o~ which water can be admitted, and of a heat barrier upstream of the heat exchanger.
It is known to feed a water mist and/or wa-ter vapor ~o internal combustion engines in order to improve combustion and hence to raise the ef~iciency. The improved combustion leads to a reduction in the proportions of CO and carbon in the exhaust gases~ In the dif~erent operating states of a motor vehicle, however, some un~avorable conditions can occur which lead to overheating in the combustion chamber, so that the ~ormation of nitric oxides is ~avored. Hitherto, it was necessary for this reason to carry out a catalytic a~ter-oxidation, in order to meet the exhaust gas regulations. This catalytic oxidation, however, leads to a loss o~ power and to considerabl~ increased manu~acturing costs for the internal combustion engine.
It is the object o~ the invention to e~fect the ~eed o~ a water mist and/or water vapor into the suction path of an internal combustion engine in such a way that, coupled with optimum e~ficiency, both the CO content and the nitric oxide content o~ the exhaust gases reach a minimum and that a catalytic a~ter-oxidation is not necessary~ , .
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To achieve this object, it is proposed according -to the invention to provide a metering device for me-tering the quantity of water, which is to be fed into the suction path, and a control device which controls the metering device as a function o~ at least one operating parameter of the internal combustion engine.
To adapt the quantity of water vapor, introduced into the suction path of the internal combustion engine, to the ~uel quantit~ corresponding to the particular operating state of the internal combustion engine, it is proposed according to the invention that the metering device is arranged upstream o~ the heat exchanger and can be controlled as a ~unction o~ the speed o~ the internal combustion engine. Only such a quantity o~ water is thùs ~ed to the heat exchanger t;hat the water vapor quantity corresponding to the particular opera~ing state of the internal combustLon engine is generated. I~ an excess o~ hot water vapor were fed into the suction path ~; o~ the internal combustion engine in the case of a low ~uel ~uantity, this would lead to high temperatures o~ the mixture, be~ore it reaches the combustion chamber o~ the internal combustion engine, and hence tounduly h~ combustion temperatures which are the cause o~ extensive formation of nitrio oxides.
To avoid ~eeding water to the heat exchanger, as long as the water in the heat exchanger cannot yet be completely vaporized, it is proposed according to the invention that the metering device can be co~trolled as a function o~ the exhaust gas temperature in the heat ' . ' ' ' ' L25 E;~
exchanger in such a way that the water is fed to the heat exchanger only when a predetermined temperature threshold value is reached~
As tests on the systems known hitherto have shown, a very high proportion of nitric oxides appears in the exhaust gases during an overrun of the internal combustion engine, that is to say at relatively high speed and with a closed throttle valve T~e reason for this is that, as a result o~ the high vacuum7 a large quantity of hot water vapor is drawn in. When the throttle valve is closed, however, only a little fuel is vaporized, so that little heat of vaporization is removed from the water vapor, This leads to high initial temperatures and hence to a rise in the combustion temperature and to increased ~orma~
tion of the nitric oxide. Moreover, when running at high altitudes (above about 2,000 m), overheating of the internal cqmbustion engine read:ily occurs with a high vapor feed, due to the lower density o~ the air, and this gives a similar resul-t.
To eliminate this disadvantage, the metering device according to the invention can be controlled as a il ! .
function of the temperature in the suction path of the internal combustion engine, downstream of the throttle valve, in such a way that the water feed ~rom the heat exchanger is restricted or switched o~ when a temperature threshold value is reached.
It is also possible to control the metering device as a funotion o~ the vacuum in the suction path o~ the int~rnal combust_on englne in ~uoh a way that the ~eed o~
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water to the heat exchanger is restricted with rising vacuum. The di~ficulties arising on the overrun can also be overcome in this way. It is su~icien-t here when the water feed is restricted or the water feed to the heat exchanger is switched off at a certain threshold value of the vacuum. In this case, the control device for actuating the metering device can, for example, com-prise a vacuum cell which is connected to a point, located downstream o~ the throttle valve, of the suction path of the internal combustion engine and which, when a threshold value of the vacuum is exceeded, actuates a limit switch which in turn leads to switching-off or to a restriction of the water ~eed.
~; In a pre~erred embodiment of the invention, the metering device comprises a pump, the delivery of which is controlled by the speed of the internal combustion engine.
Pre~erably, the pump is formed by a diaphragm pump, the diaphragm of which can be actuated by means of a ram ~ixed thereto and designed as the plunger o~ an electromagnet, and the winding o~ the electromagnet can be excited at a frequency which is proportional to the speed ~ o~ the engine. The speed of the internal combustion ;; engine can, for~example, be scanned on the contact breaker o~ the internal combustion engine~ Preferably, -the control devioe comprises in this case a pulse generator which is coupled to the contact breaker of the internal combustion engine and which9 via a flip flop circuit, actuates a switch for switching the excitation winding o~
the pump on and o~. To prolong the li~e of the pump, ~Z561~
it is advisable -to lower the number of pulses. This can be effected, for example, in such a wa~ that a pulse ~requency divider is inserted between the pulse generator and the flip-flop circuit, in order to lower the pulse frequency.
The lowering of the pulse frequency can also be utilized for restricting the delivery of the pump, for example in the overrun of the internal combustion engine. For this purpose, a further pulse frequency divider can be provided which is controlled as a function of the temperature in the suction path of the internal combustion engine in such a way that the further pulse frequency divider is switched on, and the pulse frequency is thus lowered, when the temperature in the suction path of the internal combustion engine rises above a predetermined temperature threshold value.
The pump is preferabl~ formed integrally with the heat barrier. This can be effec-ted in such a way that the pump comprises a ~ump chamber which is connected to an inlet valve and an outlet valve and in which a pump piston which can be actuated by a diaphragm is arranged in such a way that, ~0 under the action o~ a return spring, it blocks the passage between the inlet and outlet valves when the winding of the electromagnet is not excited. As in the case of the heat barrier known from our German Offenlegunschrift 26 04 050 published on August 4, 1977 a transfer of heat from the heat exchanger to the water stock tank and to the metering device is thus avoided.
According to another embodiment of the invention, the metering device comprises a pump and a metering valve .
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arrangement which is located downstr~am o~ the pump and which can be controlled as a function oP the speed o~ -the internal combustion engine in the direction of a greater throughput when the speed risesO To keep the expendi-ture on controls as low as possible, the metering valve arrangement prèferably comprises at least two metering valves which can be actuated at dif~erent speed values by maans of the control device. This means that the first meterin~ valve is opened when a certain ~irst speed value is exceeded, whilst the second metering valve lS
opened only when a second speed value at a higher level is exceeded Preferably, the metering valves are formed by solenoid valves, in which case the oontrol circuit comprises a pulse generator coupled to the contact breaker o~ the internal combustion engine andJ downstream thereo~, a fre~uency/voltage convertor, the output signal of the latter being ~ed to two comparators which are adjus~ed to di~ferent threshold values and each of which is oonnected via a switch to the excitation winding of one o~ the solenoi~ valves.
The pump o~ the embodiment ~iscussed last can be a conventional pump which is driven electrically or mechanically.
To regulate the temperature o~ the mixture in the suction path o~the internal combustion engine and, in particular, to lower the temperature of the mixture on the overrun o~ the internal combustion engine, it is also pro~
posed according to the invention that the temperature o~
the water and/or water vapor ~ed into the suction path o~
' the internal combustion engine can be regulated as a function '7 of an operating parameter oE the internal combustion engine.
This solution can be used both on its own and, in a particularly advantageous manner, in conjunction with the metering device described above. The temperature of the water vapor fed in can be regulated both as a functionof the temperature of the mixture in the suction path downstream of the throttle valve and as a function of the vacuum downstream of the throttle valve.
The temperature regulation can be effected, say, in such a way that a second heat exchanger in the form of a cooler is provided downstream of the heat exchanger and that ~-the flow rate of the coolant can be regulated as a function ~ of the operating state of the internal combustion engine. In ; another possibility, a second heat exchanger in the form of a ` vapor-mixing device is provided/ downstream of the heat exchanger, which has a valve device, which is controllable by the operating parameter of the internal combustion engine, for feeding in a vapor at a lower temperature, in order to obtain a vapor mixture which has the desired temperature. -.
According to a preferred embodiment o-f the invention, -;~ a second heat exchanger in the form of a mixing device is provided, downstream of the heat exchanger, in which water can be admixed, in a quantity depending on the operating state of the internal combustion engine, to the vapor coming ~ from the heat exchanger. The mist formation thus effected ; leads to a rapid lowering of the vapor temperature so that excessive heating of the mixture, be-fore it enters the combustion chamber/ by the vapor introduced is avoided.
/~r~
.
-- 9 ~-According to a simple embodiment, the mixing device comprises a venturi tube located in the flow path of the water vapor9 a distributor device controlling the inflow o~ water to the nozzle zone of the ven-turi tube as a ~unction o~ the operating state o~ the internal com~
bustion engine. Preferably, the distributor device is designed as a solenoid valve which can be actuated via an electrical control circuit. As an alternative there--to, it would also be possible for a second pump to deliver the water to the mixing device. Pre~erably, the solenoid valve is actua~ed as a function of a thermo-sensor in the suction path o~ the internal combustion englne, downstream o~ the throttle valve. The tempera-ture sensor can be designed in such a way that, when the temperature in the suction path rises above a predetermined threshold value, it emits a pulse which is transmitted via a pulse f`ormer to the base o~ a switching transistor which is thus switched into conduction and feeds the winding of the solenoid valve. As the temperature sensors for the case described aboveanda~oforthe illustrative embodiments described ~urther above, resistances are propcsed, the resistivities o~ which have sudden changes within a tem-perature range with narrow limits. For example, metal oxide resistances are resistances of this type, It has been ~ound in tests that the most favorable feed points for the water and/or the water vapor into the suction path o~ the internal combustion engine are located upstream and downstream of the point where mixing of air and ~uel takes place, that is to say customarily upstream and downstream of the carburetor. In this case, according to a preferred embodiment, about 75% oE the vapor are fed in upstream of the throttle valve and about 25~ are fed in downstream of the throttle valve.
In summary of all of the above, therefore, the invention as defined in this application may be considered as providing a feed system for introducing water in the liquid and/or vapor state into the suction path of an internal combustion engine, comprising a water reservoir and a first heat exchanger means for receiving exhaust gases from the internal combustion engine and for receiving water from the reservoir in heat exchange relationship with the exhaust gases, the system further comprising a second heat exchanger means, located downstream of the first heat exchanger means and up-stream of the suction path, for regulating the temperature o~
the water and/or steam to be fed into the suction path as a function of an operating parameter of the suction path.
Further features and advantages of the invention can be seen from the sub-claims and the description which ollows 2~ and which explains the invention by reference to illustrative embodiments in conjunction with the attached figures in which:
Figure 1 shows a schematic representation of a first embodiment of the feed system according to the invention, ~ Figure 2 shows a schematic representation oE a second embodiment of the feed system according to the invention, Figure 3 shows an enlarged representation of the pump shown in Figures 1 and 2, accordin~ to a flrst embodiment of the invention, Figure 4 shows an enlarged representation Qf the pump
The invention relates to a feed system for intro~
ducing water in the liquid and/or vaporous state into the suction path o~ an internal combustion engine, oonsist-ing o~ a water stock vessel, of a heat exchanger, to one side o~ which exhaust gases ~rom ~he internal combustion engine can be admitted and to the other side o~ which water can be admitted, and of a heat barrier upstream of the heat exchanger.
It is known to feed a water mist and/or wa-ter vapor ~o internal combustion engines in order to improve combustion and hence to raise the ef~iciency. The improved combustion leads to a reduction in the proportions of CO and carbon in the exhaust gases~ In the dif~erent operating states of a motor vehicle, however, some un~avorable conditions can occur which lead to overheating in the combustion chamber, so that the ~ormation of nitric oxides is ~avored. Hitherto, it was necessary for this reason to carry out a catalytic a~ter-oxidation, in order to meet the exhaust gas regulations. This catalytic oxidation, however, leads to a loss o~ power and to considerabl~ increased manu~acturing costs for the internal combustion engine.
It is the object o~ the invention to e~fect the ~eed o~ a water mist and/or water vapor into the suction path of an internal combustion engine in such a way that, coupled with optimum e~ficiency, both the CO content and the nitric oxide content o~ the exhaust gases reach a minimum and that a catalytic a~ter-oxidation is not necessary~ , .
.. . .
,~ .
, . ~ 5i6~
To achieve this object, it is proposed according -to the invention to provide a metering device for me-tering the quantity of water, which is to be fed into the suction path, and a control device which controls the metering device as a function o~ at least one operating parameter of the internal combustion engine.
To adapt the quantity of water vapor, introduced into the suction path of the internal combustion engine, to the ~uel quantit~ corresponding to the particular operating state of the internal combustion engine, it is proposed according to the invention that the metering device is arranged upstream o~ the heat exchanger and can be controlled as a ~unction o~ the speed o~ the internal combustion engine. Only such a quantity o~ water is thùs ~ed to the heat exchanger t;hat the water vapor quantity corresponding to the particular opera~ing state of the internal combustLon engine is generated. I~ an excess o~ hot water vapor were fed into the suction path ~; o~ the internal combustion engine in the case of a low ~uel ~uantity, this would lead to high temperatures o~ the mixture, be~ore it reaches the combustion chamber o~ the internal combustion engine, and hence tounduly h~ combustion temperatures which are the cause o~ extensive formation of nitrio oxides.
To avoid ~eeding water to the heat exchanger, as long as the water in the heat exchanger cannot yet be completely vaporized, it is proposed according to the invention that the metering device can be co~trolled as a function o~ the exhaust gas temperature in the heat ' . ' ' ' ' L25 E;~
exchanger in such a way that the water is fed to the heat exchanger only when a predetermined temperature threshold value is reached~
As tests on the systems known hitherto have shown, a very high proportion of nitric oxides appears in the exhaust gases during an overrun of the internal combustion engine, that is to say at relatively high speed and with a closed throttle valve T~e reason for this is that, as a result o~ the high vacuum7 a large quantity of hot water vapor is drawn in. When the throttle valve is closed, however, only a little fuel is vaporized, so that little heat of vaporization is removed from the water vapor, This leads to high initial temperatures and hence to a rise in the combustion temperature and to increased ~orma~
tion of the nitric oxide. Moreover, when running at high altitudes (above about 2,000 m), overheating of the internal cqmbustion engine read:ily occurs with a high vapor feed, due to the lower density o~ the air, and this gives a similar resul-t.
To eliminate this disadvantage, the metering device according to the invention can be controlled as a il ! .
function of the temperature in the suction path of the internal combustion engine, downstream of the throttle valve, in such a way that the water feed ~rom the heat exchanger is restricted or switched o~ when a temperature threshold value is reached.
It is also possible to control the metering device as a funotion o~ the vacuum in the suction path o~ the int~rnal combust_on englne in ~uoh a way that the ~eed o~
.
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water to the heat exchanger is restricted with rising vacuum. The di~ficulties arising on the overrun can also be overcome in this way. It is su~icien-t here when the water feed is restricted or the water feed to the heat exchanger is switched off at a certain threshold value of the vacuum. In this case, the control device for actuating the metering device can, for example, com-prise a vacuum cell which is connected to a point, located downstream o~ the throttle valve, of the suction path of the internal combustion engine and which, when a threshold value of the vacuum is exceeded, actuates a limit switch which in turn leads to switching-off or to a restriction of the water ~eed.
~; In a pre~erred embodiment of the invention, the metering device comprises a pump, the delivery of which is controlled by the speed of the internal combustion engine.
Pre~erably, the pump is formed by a diaphragm pump, the diaphragm of which can be actuated by means of a ram ~ixed thereto and designed as the plunger o~ an electromagnet, and the winding o~ the electromagnet can be excited at a frequency which is proportional to the speed ~ o~ the engine. The speed of the internal combustion ;; engine can, for~example, be scanned on the contact breaker o~ the internal combustion engine~ Preferably, -the control devioe comprises in this case a pulse generator which is coupled to the contact breaker of the internal combustion engine and which9 via a flip flop circuit, actuates a switch for switching the excitation winding o~
the pump on and o~. To prolong the li~e of the pump, ~Z561~
it is advisable -to lower the number of pulses. This can be effected, for example, in such a wa~ that a pulse ~requency divider is inserted between the pulse generator and the flip-flop circuit, in order to lower the pulse frequency.
The lowering of the pulse frequency can also be utilized for restricting the delivery of the pump, for example in the overrun of the internal combustion engine. For this purpose, a further pulse frequency divider can be provided which is controlled as a function of the temperature in the suction path of the internal combustion engine in such a way that the further pulse frequency divider is switched on, and the pulse frequency is thus lowered, when the temperature in the suction path of the internal combustion engine rises above a predetermined temperature threshold value.
The pump is preferabl~ formed integrally with the heat barrier. This can be effec-ted in such a way that the pump comprises a ~ump chamber which is connected to an inlet valve and an outlet valve and in which a pump piston which can be actuated by a diaphragm is arranged in such a way that, ~0 under the action o~ a return spring, it blocks the passage between the inlet and outlet valves when the winding of the electromagnet is not excited. As in the case of the heat barrier known from our German Offenlegunschrift 26 04 050 published on August 4, 1977 a transfer of heat from the heat exchanger to the water stock tank and to the metering device is thus avoided.
According to another embodiment of the invention, the metering device comprises a pump and a metering valve .
ws /
arrangement which is located downstr~am o~ the pump and which can be controlled as a function oP the speed o~ -the internal combustion engine in the direction of a greater throughput when the speed risesO To keep the expendi-ture on controls as low as possible, the metering valve arrangement prèferably comprises at least two metering valves which can be actuated at dif~erent speed values by maans of the control device. This means that the first meterin~ valve is opened when a certain ~irst speed value is exceeded, whilst the second metering valve lS
opened only when a second speed value at a higher level is exceeded Preferably, the metering valves are formed by solenoid valves, in which case the oontrol circuit comprises a pulse generator coupled to the contact breaker o~ the internal combustion engine andJ downstream thereo~, a fre~uency/voltage convertor, the output signal of the latter being ~ed to two comparators which are adjus~ed to di~ferent threshold values and each of which is oonnected via a switch to the excitation winding of one o~ the solenoi~ valves.
The pump o~ the embodiment ~iscussed last can be a conventional pump which is driven electrically or mechanically.
To regulate the temperature o~ the mixture in the suction path o~the internal combustion engine and, in particular, to lower the temperature of the mixture on the overrun o~ the internal combustion engine, it is also pro~
posed according to the invention that the temperature o~
the water and/or water vapor ~ed into the suction path o~
' the internal combustion engine can be regulated as a function '7 of an operating parameter oE the internal combustion engine.
This solution can be used both on its own and, in a particularly advantageous manner, in conjunction with the metering device described above. The temperature of the water vapor fed in can be regulated both as a functionof the temperature of the mixture in the suction path downstream of the throttle valve and as a function of the vacuum downstream of the throttle valve.
The temperature regulation can be effected, say, in such a way that a second heat exchanger in the form of a cooler is provided downstream of the heat exchanger and that ~-the flow rate of the coolant can be regulated as a function ~ of the operating state of the internal combustion engine. In ; another possibility, a second heat exchanger in the form of a ` vapor-mixing device is provided/ downstream of the heat exchanger, which has a valve device, which is controllable by the operating parameter of the internal combustion engine, for feeding in a vapor at a lower temperature, in order to obtain a vapor mixture which has the desired temperature. -.
According to a preferred embodiment o-f the invention, -;~ a second heat exchanger in the form of a mixing device is provided, downstream of the heat exchanger, in which water can be admixed, in a quantity depending on the operating state of the internal combustion engine, to the vapor coming ~ from the heat exchanger. The mist formation thus effected ; leads to a rapid lowering of the vapor temperature so that excessive heating of the mixture, be-fore it enters the combustion chamber/ by the vapor introduced is avoided.
/~r~
.
-- 9 ~-According to a simple embodiment, the mixing device comprises a venturi tube located in the flow path of the water vapor9 a distributor device controlling the inflow o~ water to the nozzle zone of the ven-turi tube as a ~unction o~ the operating state o~ the internal com~
bustion engine. Preferably, the distributor device is designed as a solenoid valve which can be actuated via an electrical control circuit. As an alternative there--to, it would also be possible for a second pump to deliver the water to the mixing device. Pre~erably, the solenoid valve is actua~ed as a function of a thermo-sensor in the suction path o~ the internal combustion englne, downstream o~ the throttle valve. The tempera-ture sensor can be designed in such a way that, when the temperature in the suction path rises above a predetermined threshold value, it emits a pulse which is transmitted via a pulse f`ormer to the base o~ a switching transistor which is thus switched into conduction and feeds the winding of the solenoid valve. As the temperature sensors for the case described aboveanda~oforthe illustrative embodiments described ~urther above, resistances are propcsed, the resistivities o~ which have sudden changes within a tem-perature range with narrow limits. For example, metal oxide resistances are resistances of this type, It has been ~ound in tests that the most favorable feed points for the water and/or the water vapor into the suction path o~ the internal combustion engine are located upstream and downstream of the point where mixing of air and ~uel takes place, that is to say customarily upstream and downstream of the carburetor. In this case, according to a preferred embodiment, about 75% oE the vapor are fed in upstream of the throttle valve and about 25~ are fed in downstream of the throttle valve.
In summary of all of the above, therefore, the invention as defined in this application may be considered as providing a feed system for introducing water in the liquid and/or vapor state into the suction path of an internal combustion engine, comprising a water reservoir and a first heat exchanger means for receiving exhaust gases from the internal combustion engine and for receiving water from the reservoir in heat exchange relationship with the exhaust gases, the system further comprising a second heat exchanger means, located downstream of the first heat exchanger means and up-stream of the suction path, for regulating the temperature o~
the water and/or steam to be fed into the suction path as a function of an operating parameter of the suction path.
Further features and advantages of the invention can be seen from the sub-claims and the description which ollows 2~ and which explains the invention by reference to illustrative embodiments in conjunction with the attached figures in which:
Figure 1 shows a schematic representation of a first embodiment of the feed system according to the invention, ~ Figure 2 shows a schematic representation oE a second embodiment of the feed system according to the invention, Figure 3 shows an enlarged representation of the pump shown in Figures 1 and 2, accordin~ to a flrst embodiment of the invention, Figure 4 shows an enlarged representation Qf the pump
3~ shown in Figures 1 and ~, according to a second embodiment o~
the invention, Figure 5 shows a schematic circuit diagram of the control circuit for a feed system according to Figure 1, and .
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Figure 6 shows a schematic ci.rcuit diagram of the control c.ircuit for a feed system according to Figure 2.
The feed system, shown in Figure 1, for introducing water in the liquid and/or vaporous state into the suction path of an internal combustion engine comprises a water .. . .
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- lOa j r/f~
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stock vessel 10 and a filter 14 which is connected thereto via a line 12 and which is adjoined via a line 16 by a pump generally marked 18. From the delivery side of the pump 18, a line 20 leads via a distributor device in the ~orm of a controllable 2-way solenoid valve 128 and a valve 201 to a heat exchanger 22 which is adjoined by a mixing device 24 ~or mixing the vapor, formed ln the heat exchanger 22, with water which is fed to the mixing device 24 direc-tl~, by-passing the heat exchanger 22, ~rom the delivery side of the pump 18 via the solenoid valve 128 and a line 26. In a manner which will yet be described in more detail, a line 28 leads from the mixing device to the mixture Pormation system 30 of an internal combustion enginej which is not shown, comprising an air filter 32, a carburetor 34 with a throttle valve 36 and a venturi throa-t 38 as well as a suction line 40.
The heat exchanger 22 comprises an exhaust gas pipe 42, through which the hot exhaust gases from the internal combustion engine flow and which is surrounded by an outer jacket 44 into which water flows from the pump 18 via the line 20 and ~rom which the water, a~ter vaporiza-~ion on the hot exhaust gas pipe 42, ~lows out via the line 46 towards the mixing devlce 24, ~ A first temperature sensor 48 for measuring the exhaust gas temperature is located on the exhaust gas pipe 42.
A second temperature sensor 50 for measuring the temperature o~ the mixture immediately be~ore it enters the oombustio~ chamber of the internal com.ustion engine, 3~
is located on the suction line 40 downstream of the carburetor 34 The two temperature sensors 48 and 50 are preferably formed by temperature-dependent resistances, o~ which the change in resistance takes place within a narrow -temperature range. Temperature-dependent resistances o~ this type are, for example, certain metal oxide resistances (MOXIE).
A vacuum cell 54 with a spring-loaded diaphragm 56, to which a ram 58 which can be moved up and do~n by the diaphragm is ~ixed, is connected to the suction line 40 in the zone of the venturi throat 38 via a vacuum line 52, In the rest position of the vacuum cell 54, that is to say when no vacuum or only a slight vacuum acts on that side of the diaphragm 56 which ~aces the vacuum line 52, this ram actuates a limit switch 60, the functioning o~
which will be described in more detail belowc When a high vacuum occurs downstream o~ the throttle valve 36, the diaphragm 56, and together with it the ram 58, are moved against the spring ~orce o~ the spring 62 and the ram 58 is th~s li~ted off the limit switch 60.
The diagrammatically indicated contact breaker 64 o~ the internal combustion engine can also be seen in Figure 1. Together with the temperature sensors 48 and 50 as well as the limit switch 60, this contact breaker provides the input values for a control circuit generally marked 11, as is indicated by the arrows leading ~rom the contact breaker 64, the temperature sensors 48 50 and the lim~t switch 60 to the control circuit 11 As a function o~ the input values th~s re.ceived, the control circuit 11 controls the pump 18 and also the solenoid valve 128, as is indicated by the arrows leading from the control device 11 to the pump 18 and to the solenoid valve 1280 Before the design o~ the control circuit and the mode of operation of the feed system are discussed, two illustrative embodiments of the diaphragm pump 18, driven as a function of the speed of the internal combustion engine 9 are to be described first.
The embodiment shown in Figure 3 comprises a pump casing 66 with a pump chamber-which is subdivided by an annular projection 68 pointing radially inwards into two half chambers 70 and 72. The upper half chamber 70 is connected via an inlet valve 76 to an inlet branch 74.
The inlet valve 76 has a valve disc 78 which is tensioned against a val~e seat 82 py means o~ a spring 80. The lower half chamber 72 is connected via an outlet valve 84 to an outlet branch 86. The outlet valve 84 has a valve disc 88 which is .tensioned against a valve se~ 92 by means o~ a spring 90 In the lower hal~ chamber 72, a piston 94 can be moved up and down, of which the end ~acing the half chamber 70 carries, on a cylindrical projection 96, a valve element 98 which7 in the lower position of the pis~
ton 94, closes the aperture 100 in the annular projection 68~
The piston 94 is-fixed to à diaphragm 102 to which a ram 104 is fastened on the side facing awa~ from the piston 94, which ram plunges into the central bore 106 o~ an electromagnet 110, the pot-shaped housLng 108 ~ Q ~
of which is flanged to the pump casing 66. The ram 104 here carries on its end away from the diaphragm a piston-like thickening 112 which, when the winding 114 of the electromagnet 110 is not excited, par-tially protrudes from the central bore 106 and is held in this position by a lea~ spring 116 which is ~ixed to the pot-shaped housing 108. When the winding 114 is excited, the thickening 112 is drawn into the central bore 106 against, ehe resis-tance of the leaf spring and the piston 94 is thus pressed upwards via the ram 104 and the diaphragm 102. The liquid contained in the lower half chamber 72 is thus forced out of the pump chamber through the outlet valve 84.
When the electromagnet 110 is switched off, the piston 94 is again pressed downwards by the leaf spring 116 via the diaphragm 102 and the ram 104, l:iquid being drawn into the upper half chamber 70 via the in:Le-t valve 76. The diaphragm 102 mainly serves for sealing the pump chamber 70, 72 so that the piston 94 can have a slightl~ smaller diameter than the lower half chamber 7~. This has the advantage that the piston 94 cannot jam due to expansion of the material when the pump 18 warms up.
The two valves 76 and 84 together form a heat barrier which prevents a transfer of heat from the heat exchanger 22 back to the water stock vessel 10. Com-pared with the conventional heat barrier, the pump 18 according to the invention has~ however, a decisive advan-tage. In a heat barrier which works automatically the internal combustion engine extracts the water vapor from the heat,exchanger until the water pressure applying '.
.
~2S~
to the heat barrier can open the valves of the heat barrier Since.there is a considerable difference between the maximum vapor pressure and the upstream water pressure, a continually ~luctuating quantity o~ vapor is supplied to the suction system an~, moreover, this is the smaller, the smaller the vacuum in the suction system, Precisely in the case o~ a small vacuum, which corres-ponds to opening o~ the throttle valve, however, a large quantity o~ fuel is drawn in and, consequently, a large ~uantity o.~ water vapor would also have to be fed in in order to make the heat of vaporization for the fuel available. This is now accomplished by the pump 18 according to the invention, the number o~ strokes o~ which is dependent on the speed o~ the internal combustion engine. Thus, as can readily be seen, the quantity of .vapor made available by the heat exchanger rises pro-portionally to the speed o~ the in.ternal combus-tion engine since, with rising speed, the pump 18`delivers more water into the heat exchanger. The inlet valve 76 here works as a non-return valve in the direction o~ the water vessel 10, and the outlet valve 84 prevents the water vapor from acting back on the pump 18 The second embodlment o~ the pump 18 accordlng to the invention, described in Figure 4, differs from the pump described above essentially`in that the inlet valve 76 and the outlet valve 84 are in a mutually aligned position, separated from one another only by a bore 118 A piston 120 can be moved in the bore 118 by means o~ the diaphragm 102, which piston has the purpose o~ blocking the bore ll8 as well as drawing in water through the inlet valve 76 and delivering it through the outlet valve 84. When current does not flow through the winding 114, the coil spring 122 forces the piston 120 via the ram 104 and the diaphragm 102 into the bore 118. In operation, the pump works by way o~ the diaphragm 102 and the valves 76 and 84, and additionally with the piston 120, as a pump having a pressure which is increased as compared with a simple diaphragm pump.
The mixing device 24 shown in Figure 1 comprises a venturi tube 124 which is located between the lines 46 and 28 and through which the water vapor drawn from t~e outer jacket 44 oP the heat exchanger 22 ~lows. A nozzle 126 connected to the line 26 ends in the throat zone o~ the venturi tube 124, and the connection between the pump 18 and the nozzle :L26 can be blocked by a solenoid valve 128, With the solenoid valve 128 open, water is injected into the venturi tube 124 through the nozzle 126 and is atomized to gi~e fine mist droplets ~hen it enters into the hot vapor ~lowing through, The hot vapor ~lowing through is thus cooled.
The control circuit 11, shown in Figure 5, ~or the feed sy~tem reproduced in Figure 1 comprises a pump control circui-t 130 and a mixer control circuit 132. The two circuits are oonnected via the limit switch 60 and the - thermo-sen~or 43 to -the positive pole o~ a voltage source.
When the limit switch 60 is opened by the ram of the vacuum cell 54 because o~ a high ~acuum in the suction line 40~ neither the`pump 1~ noF the solenoid valve 128 :, .:
~L~25~
are supplied with current so that no water feed at all to the suction system of the internal combustion engine takes place The same applies as long as the exhaust gas temperature in the exhaust gas pipe 42 has not yet reached a defined temperature threshold value which in the present case is about 110. This temperature enables the water ~ed to the heat exchanger 22 to be vaporized.
Below 100, however, the water would not be vaporized completely The pump control circuit 130 compri.ses a pulse generator 134 which is controlled by the contact breaker ~4 of the internal combustion engine The pulses generated by the pulse generator 134 are transmitted to a pulse former 136. The pulse frequency is reduced in the ratio o~ 16:1 in a pulse frequency divider 138. In a mo.nostable multi-vibrator 140 ~ollowing the pulse fre-quency divider 1~8, a pulse of a duration of about 20 milliseconds is generated The output of the mono-stable multi-vibrator 140 is connected to the base of a power transistor 142 which is switched into conduction by the output signal of~the monostable multi vibrator, whereby the linear motor 110 or the winding 114 of the pump 18 is excited and the latter is thus set in motion~
It ~ould also be possible, downstream o~ the pulse frequency divider 1389 to provide a further pulse fre-quency divider which) ~or example, halves the ~requency again and thus reduces the output of the pump 18 as a ~mction of the thermo-sensor 50 when the temperature rises above a defined threshold~ value m the suction line , 40, The mixer control circuit 132 is controlled by -the thermo-sensor 50~ When the temperature in the suction line 40 rises above about 75, this sensor generates a pulse which is fed to a pulse former 144 which in turn controls the base of a transistor 146.
In this way, the transistor 146 is switched into con-duction and the winding of the solenoid valve 128 is thus excited. When current flows through the winding of -the solenoid valve 128, this is switched over so -that water is admixed to the stream of vapor flowing through the venturi tube 124 As already stated above, the thermo-sensors are formed by temperature-dependent resistances In order to achieve reliable switching with these temperature-dependent resistances, the latter show hysteresis behaviour within their switching range~
The embodiment of the feed system according to -the invention, ~hown in Fig~re 2, dif~ers ~rom the embodiment according to Figure l in that the pump 148 is driven in a manner which is not dependent on the speed. Any desired suitable pump can be used here. The line 20 adjoining the deliver~ side of the pump 148 forks into two branches 150 and 152 which can each be blocked by a solenoid valve 154 and 156 respectively. Downstream of the -two solenoid valves 154 and 156, the two line branches 150 and 152 join up again to a line 158, a hea-t barrler 160 as described in German Laid-Open Application 29604,250 ~eing locat~d between the line 158 and the heat .
~$~i6~
exchanger 22.
The two solenoid valves 154 and 156 can be con-trolled via a valve.control circuit 162 as a function of the speed or o~ the switching ~requency o~ the contact breaker 64 o~ the internal combustion engine.
The valve control circuit 162 is reproduced in Figure 6. A pulse generator 164 is coupled to the con-tact breaker 64. The pulses thus generated are trans-mitted via a pulse former to a ~requency/voltage convertor 168~ The voltage signal generated by the latter is fed, respectively, to one input 170, 172 of a comparator 174 or 176~ A voltage which is adjustable by a variable resistance 182 or 184 is applied .in each case to the other ~inpu-t 178, 180 of the comparator :L74 or 176 respectively.
The two voltages at the resistances 182, 184 are here different. When the voltage signal at the particular input 170 or 172 of the compara-tors 174 and 176 reaches the threshold value applied in each case to the other input 178 or 180 respectively, an output signal appears on the comparator, which output signal switches one of the power transistors 186 or 188 lnto conductionO In this way the valves 154 or 156 are opened. Since the threshold values on the two comparators 174 and 176 are set to dif`ferent levels, the solenoid.valves 154 and 156 open at di~erent speeds o~ the internal combustion engine so t~at thequantity of water ~ed to the heat exchanger 22 .
can be metered according to. the speed o~ the internal combustion engine.
In the ~eed s~stem represented in Figure 2, neither .. . . .
~5~
a thermo-sensor on the exhaust.gas pipe 42 nor a thermo-sensor on the suction line 40 nor a vacuum cell 54 were shown.. It is to be understood that all three sensors can also be installed in the feed system according to Figure 2, in which case the control device 162 would then have to be complementecL corresponding to the control cir-cuit in Figure 5~
The pump 148 can likewise be formed by one of the ~.
pumps described by reference to Figures 3 and 4. How-ever, a simple conventional, mechanically driven pump also suffices As can be seen in Figures 1 and 2, the water vapor is ~ed to the suction system via two lines 190 and 192.
The line 190 ends in the suction line 40 above the car-buretor 34. About 75% o~ the water vapor are intro-duced via this line into the suction line 40. The lower line 192 ends in the suction line 40 below the carburetor 34. ~ia this line, about-25% of the hot vapor àre fed in. To pre~ent air being drawn in via.the lin~l90 ànd 192, b~passing the throttle valve 36, when the vapor feed is switched of~ and when the throttle valve is closed, a shut~-o~ element 194 is provided in the line 190.
Under certain circumstances, it is also sufficient to design the cor~ecting line in such a way that it has.a su~ficientl~ high flow resistance for airO Thus, for example, tha connecting.line could also be designed as a hose with an.inserted helix.
Moreover, it should be noted that it would also be possible to use7 in plaoe o~ the vacuum cell 54, a ' contact on the throttle valve or on the gas linkage of the int~ernal combustion engine, in order to detect over-running. This does not, however, cover the case of driving at high altitudes or under other conditions which lead to overheating of the internal combustion engine.
The feed system according to thelinvention ensures adaptation of the quantity of water vapor to be fed in to the particular operating state of the internal combustion engine so that overheating o~ the mixture before it enters the combustion chamber of the internal combustion engine can be avoided and thus, in particular, the pro-duction of nitric oxides can be substantially reduced.
, ~ ., .
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the invention, Figure 5 shows a schematic circuit diagram of the control circuit for a feed system according to Figure 1, and .
r/~
, ~IL25i~
Figure 6 shows a schematic ci.rcuit diagram of the control c.ircuit for a feed system according to Figure 2.
The feed system, shown in Figure 1, for introducing water in the liquid and/or vaporous state into the suction path of an internal combustion engine comprises a water .. . .
.
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. .
.. ..
':
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- . .. . .
stock vessel 10 and a filter 14 which is connected thereto via a line 12 and which is adjoined via a line 16 by a pump generally marked 18. From the delivery side of the pump 18, a line 20 leads via a distributor device in the ~orm of a controllable 2-way solenoid valve 128 and a valve 201 to a heat exchanger 22 which is adjoined by a mixing device 24 ~or mixing the vapor, formed ln the heat exchanger 22, with water which is fed to the mixing device 24 direc-tl~, by-passing the heat exchanger 22, ~rom the delivery side of the pump 18 via the solenoid valve 128 and a line 26. In a manner which will yet be described in more detail, a line 28 leads from the mixing device to the mixture Pormation system 30 of an internal combustion enginej which is not shown, comprising an air filter 32, a carburetor 34 with a throttle valve 36 and a venturi throa-t 38 as well as a suction line 40.
The heat exchanger 22 comprises an exhaust gas pipe 42, through which the hot exhaust gases from the internal combustion engine flow and which is surrounded by an outer jacket 44 into which water flows from the pump 18 via the line 20 and ~rom which the water, a~ter vaporiza-~ion on the hot exhaust gas pipe 42, ~lows out via the line 46 towards the mixing devlce 24, ~ A first temperature sensor 48 for measuring the exhaust gas temperature is located on the exhaust gas pipe 42.
A second temperature sensor 50 for measuring the temperature o~ the mixture immediately be~ore it enters the oombustio~ chamber of the internal com.ustion engine, 3~
is located on the suction line 40 downstream of the carburetor 34 The two temperature sensors 48 and 50 are preferably formed by temperature-dependent resistances, o~ which the change in resistance takes place within a narrow -temperature range. Temperature-dependent resistances o~ this type are, for example, certain metal oxide resistances (MOXIE).
A vacuum cell 54 with a spring-loaded diaphragm 56, to which a ram 58 which can be moved up and do~n by the diaphragm is ~ixed, is connected to the suction line 40 in the zone of the venturi throat 38 via a vacuum line 52, In the rest position of the vacuum cell 54, that is to say when no vacuum or only a slight vacuum acts on that side of the diaphragm 56 which ~aces the vacuum line 52, this ram actuates a limit switch 60, the functioning o~
which will be described in more detail belowc When a high vacuum occurs downstream o~ the throttle valve 36, the diaphragm 56, and together with it the ram 58, are moved against the spring ~orce o~ the spring 62 and the ram 58 is th~s li~ted off the limit switch 60.
The diagrammatically indicated contact breaker 64 o~ the internal combustion engine can also be seen in Figure 1. Together with the temperature sensors 48 and 50 as well as the limit switch 60, this contact breaker provides the input values for a control circuit generally marked 11, as is indicated by the arrows leading ~rom the contact breaker 64, the temperature sensors 48 50 and the lim~t switch 60 to the control circuit 11 As a function o~ the input values th~s re.ceived, the control circuit 11 controls the pump 18 and also the solenoid valve 128, as is indicated by the arrows leading from the control device 11 to the pump 18 and to the solenoid valve 1280 Before the design o~ the control circuit and the mode of operation of the feed system are discussed, two illustrative embodiments of the diaphragm pump 18, driven as a function of the speed of the internal combustion engine 9 are to be described first.
The embodiment shown in Figure 3 comprises a pump casing 66 with a pump chamber-which is subdivided by an annular projection 68 pointing radially inwards into two half chambers 70 and 72. The upper half chamber 70 is connected via an inlet valve 76 to an inlet branch 74.
The inlet valve 76 has a valve disc 78 which is tensioned against a val~e seat 82 py means o~ a spring 80. The lower half chamber 72 is connected via an outlet valve 84 to an outlet branch 86. The outlet valve 84 has a valve disc 88 which is .tensioned against a valve se~ 92 by means o~ a spring 90 In the lower hal~ chamber 72, a piston 94 can be moved up and down, of which the end ~acing the half chamber 70 carries, on a cylindrical projection 96, a valve element 98 which7 in the lower position of the pis~
ton 94, closes the aperture 100 in the annular projection 68~
The piston 94 is-fixed to à diaphragm 102 to which a ram 104 is fastened on the side facing awa~ from the piston 94, which ram plunges into the central bore 106 o~ an electromagnet 110, the pot-shaped housLng 108 ~ Q ~
of which is flanged to the pump casing 66. The ram 104 here carries on its end away from the diaphragm a piston-like thickening 112 which, when the winding 114 of the electromagnet 110 is not excited, par-tially protrudes from the central bore 106 and is held in this position by a lea~ spring 116 which is ~ixed to the pot-shaped housing 108. When the winding 114 is excited, the thickening 112 is drawn into the central bore 106 against, ehe resis-tance of the leaf spring and the piston 94 is thus pressed upwards via the ram 104 and the diaphragm 102. The liquid contained in the lower half chamber 72 is thus forced out of the pump chamber through the outlet valve 84.
When the electromagnet 110 is switched off, the piston 94 is again pressed downwards by the leaf spring 116 via the diaphragm 102 and the ram 104, l:iquid being drawn into the upper half chamber 70 via the in:Le-t valve 76. The diaphragm 102 mainly serves for sealing the pump chamber 70, 72 so that the piston 94 can have a slightl~ smaller diameter than the lower half chamber 7~. This has the advantage that the piston 94 cannot jam due to expansion of the material when the pump 18 warms up.
The two valves 76 and 84 together form a heat barrier which prevents a transfer of heat from the heat exchanger 22 back to the water stock vessel 10. Com-pared with the conventional heat barrier, the pump 18 according to the invention has~ however, a decisive advan-tage. In a heat barrier which works automatically the internal combustion engine extracts the water vapor from the heat,exchanger until the water pressure applying '.
.
~2S~
to the heat barrier can open the valves of the heat barrier Since.there is a considerable difference between the maximum vapor pressure and the upstream water pressure, a continually ~luctuating quantity o~ vapor is supplied to the suction system an~, moreover, this is the smaller, the smaller the vacuum in the suction system, Precisely in the case o~ a small vacuum, which corres-ponds to opening o~ the throttle valve, however, a large quantity o~ fuel is drawn in and, consequently, a large ~uantity o.~ water vapor would also have to be fed in in order to make the heat of vaporization for the fuel available. This is now accomplished by the pump 18 according to the invention, the number o~ strokes o~ which is dependent on the speed o~ the internal combustion engine. Thus, as can readily be seen, the quantity of .vapor made available by the heat exchanger rises pro-portionally to the speed o~ the in.ternal combus-tion engine since, with rising speed, the pump 18`delivers more water into the heat exchanger. The inlet valve 76 here works as a non-return valve in the direction o~ the water vessel 10, and the outlet valve 84 prevents the water vapor from acting back on the pump 18 The second embodlment o~ the pump 18 accordlng to the invention, described in Figure 4, differs from the pump described above essentially`in that the inlet valve 76 and the outlet valve 84 are in a mutually aligned position, separated from one another only by a bore 118 A piston 120 can be moved in the bore 118 by means o~ the diaphragm 102, which piston has the purpose o~ blocking the bore ll8 as well as drawing in water through the inlet valve 76 and delivering it through the outlet valve 84. When current does not flow through the winding 114, the coil spring 122 forces the piston 120 via the ram 104 and the diaphragm 102 into the bore 118. In operation, the pump works by way o~ the diaphragm 102 and the valves 76 and 84, and additionally with the piston 120, as a pump having a pressure which is increased as compared with a simple diaphragm pump.
The mixing device 24 shown in Figure 1 comprises a venturi tube 124 which is located between the lines 46 and 28 and through which the water vapor drawn from t~e outer jacket 44 oP the heat exchanger 22 ~lows. A nozzle 126 connected to the line 26 ends in the throat zone o~ the venturi tube 124, and the connection between the pump 18 and the nozzle :L26 can be blocked by a solenoid valve 128, With the solenoid valve 128 open, water is injected into the venturi tube 124 through the nozzle 126 and is atomized to gi~e fine mist droplets ~hen it enters into the hot vapor ~lowing through, The hot vapor ~lowing through is thus cooled.
The control circuit 11, shown in Figure 5, ~or the feed sy~tem reproduced in Figure 1 comprises a pump control circui-t 130 and a mixer control circuit 132. The two circuits are oonnected via the limit switch 60 and the - thermo-sen~or 43 to -the positive pole o~ a voltage source.
When the limit switch 60 is opened by the ram of the vacuum cell 54 because o~ a high ~acuum in the suction line 40~ neither the`pump 1~ noF the solenoid valve 128 :, .:
~L~25~
are supplied with current so that no water feed at all to the suction system of the internal combustion engine takes place The same applies as long as the exhaust gas temperature in the exhaust gas pipe 42 has not yet reached a defined temperature threshold value which in the present case is about 110. This temperature enables the water ~ed to the heat exchanger 22 to be vaporized.
Below 100, however, the water would not be vaporized completely The pump control circuit 130 compri.ses a pulse generator 134 which is controlled by the contact breaker ~4 of the internal combustion engine The pulses generated by the pulse generator 134 are transmitted to a pulse former 136. The pulse frequency is reduced in the ratio o~ 16:1 in a pulse frequency divider 138. In a mo.nostable multi-vibrator 140 ~ollowing the pulse fre-quency divider 1~8, a pulse of a duration of about 20 milliseconds is generated The output of the mono-stable multi-vibrator 140 is connected to the base of a power transistor 142 which is switched into conduction by the output signal of~the monostable multi vibrator, whereby the linear motor 110 or the winding 114 of the pump 18 is excited and the latter is thus set in motion~
It ~ould also be possible, downstream o~ the pulse frequency divider 1389 to provide a further pulse fre-quency divider which) ~or example, halves the ~requency again and thus reduces the output of the pump 18 as a ~mction of the thermo-sensor 50 when the temperature rises above a defined threshold~ value m the suction line , 40, The mixer control circuit 132 is controlled by -the thermo-sensor 50~ When the temperature in the suction line 40 rises above about 75, this sensor generates a pulse which is fed to a pulse former 144 which in turn controls the base of a transistor 146.
In this way, the transistor 146 is switched into con-duction and the winding of the solenoid valve 128 is thus excited. When current flows through the winding of -the solenoid valve 128, this is switched over so -that water is admixed to the stream of vapor flowing through the venturi tube 124 As already stated above, the thermo-sensors are formed by temperature-dependent resistances In order to achieve reliable switching with these temperature-dependent resistances, the latter show hysteresis behaviour within their switching range~
The embodiment of the feed system according to -the invention, ~hown in Fig~re 2, dif~ers ~rom the embodiment according to Figure l in that the pump 148 is driven in a manner which is not dependent on the speed. Any desired suitable pump can be used here. The line 20 adjoining the deliver~ side of the pump 148 forks into two branches 150 and 152 which can each be blocked by a solenoid valve 154 and 156 respectively. Downstream of the -two solenoid valves 154 and 156, the two line branches 150 and 152 join up again to a line 158, a hea-t barrler 160 as described in German Laid-Open Application 29604,250 ~eing locat~d between the line 158 and the heat .
~$~i6~
exchanger 22.
The two solenoid valves 154 and 156 can be con-trolled via a valve.control circuit 162 as a function of the speed or o~ the switching ~requency o~ the contact breaker 64 o~ the internal combustion engine.
The valve control circuit 162 is reproduced in Figure 6. A pulse generator 164 is coupled to the con-tact breaker 64. The pulses thus generated are trans-mitted via a pulse former to a ~requency/voltage convertor 168~ The voltage signal generated by the latter is fed, respectively, to one input 170, 172 of a comparator 174 or 176~ A voltage which is adjustable by a variable resistance 182 or 184 is applied .in each case to the other ~inpu-t 178, 180 of the comparator :L74 or 176 respectively.
The two voltages at the resistances 182, 184 are here different. When the voltage signal at the particular input 170 or 172 of the compara-tors 174 and 176 reaches the threshold value applied in each case to the other input 178 or 180 respectively, an output signal appears on the comparator, which output signal switches one of the power transistors 186 or 188 lnto conductionO In this way the valves 154 or 156 are opened. Since the threshold values on the two comparators 174 and 176 are set to dif`ferent levels, the solenoid.valves 154 and 156 open at di~erent speeds o~ the internal combustion engine so t~at thequantity of water ~ed to the heat exchanger 22 .
can be metered according to. the speed o~ the internal combustion engine.
In the ~eed s~stem represented in Figure 2, neither .. . . .
~5~
a thermo-sensor on the exhaust.gas pipe 42 nor a thermo-sensor on the suction line 40 nor a vacuum cell 54 were shown.. It is to be understood that all three sensors can also be installed in the feed system according to Figure 2, in which case the control device 162 would then have to be complementecL corresponding to the control cir-cuit in Figure 5~
The pump 148 can likewise be formed by one of the ~.
pumps described by reference to Figures 3 and 4. How-ever, a simple conventional, mechanically driven pump also suffices As can be seen in Figures 1 and 2, the water vapor is ~ed to the suction system via two lines 190 and 192.
The line 190 ends in the suction line 40 above the car-buretor 34. About 75% o~ the water vapor are intro-duced via this line into the suction line 40. The lower line 192 ends in the suction line 40 below the carburetor 34. ~ia this line, about-25% of the hot vapor àre fed in. To pre~ent air being drawn in via.the lin~l90 ànd 192, b~passing the throttle valve 36, when the vapor feed is switched of~ and when the throttle valve is closed, a shut~-o~ element 194 is provided in the line 190.
Under certain circumstances, it is also sufficient to design the cor~ecting line in such a way that it has.a su~ficientl~ high flow resistance for airO Thus, for example, tha connecting.line could also be designed as a hose with an.inserted helix.
Moreover, it should be noted that it would also be possible to use7 in plaoe o~ the vacuum cell 54, a ' contact on the throttle valve or on the gas linkage of the int~ernal combustion engine, in order to detect over-running. This does not, however, cover the case of driving at high altitudes or under other conditions which lead to overheating of the internal combustion engine.
The feed system according to thelinvention ensures adaptation of the quantity of water vapor to be fed in to the particular operating state of the internal combustion engine so that overheating o~ the mixture before it enters the combustion chamber of the internal combustion engine can be avoided and thus, in particular, the pro-duction of nitric oxides can be substantially reduced.
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Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A feed system for introducing water in the liquid and/or vapor state into the suction path of an internal combustion engine, comprising a water reservoir and a first heat exchanger means for receiving exhaust gases from the internal combustion engine and for receiving water from said reservoir in heat exchange relationship with said exhaust gases, said system further comprising a second heat exchanger means, located downstream of said first heat exchanger means and upstream of said suction path, for regulating the temperature of the water and/or steam to be fed into the suction path as a function of an operating parameter of the suction path.
2. A feed system as claimed in claim 1, wherein said second heat exchanger means regulates the said temperature as a function of the temperature of the mixture in the suction path of the internal combustion engine.
3. A feed system as claimed in claim 1 or 2, wherein said second heat exchanger means regulates the said temperature as a function of the vacuum in the suction path of the internal combustion engine.
4. A feed system as claimed in any one of claims 1 and 2, wherein said second heat exchanger means comprises a cooler located downstream of the first heat exchanger means and wherein the flow rate of coolant is regulated as a function of the operating state of the internal combustion engine.
5. A feed system as claimed in any one of claims 1 and 2, wherein said second heat exchanger means comprises a vapor-mixing device which has a valve means, controlled by an operating parameter of the internal combustion engine, for controlling feeding of a vapor to said vapor-mixing device in order to adjust the vapor mixture to a defined temperature.
6. A feed system as claimed in claim 1, wherein said second heat exchanger means comprises a mixing device in which water can be admixed, in a quantity depending on the operating state of the internal combustion engine, with the vapor coming from the first heat exchanger means.
7. A feed system as claimed in claim 6, wherein the mixing device comprises a venturi tube located in the flow path of the water vapor and a distributor device is provided which controls the inflow of water to the throat zone of the venturi tube.
8. A feed system as claimed in claim 7, wherein the distributor device comprises a solenoid valve which can be actuated via an electrical control circuit.
9. A feed system as claimed in claim 8, wherein the control circuit comprises a thermo-sensor and a pulse former which is connected to said thermo-sensor and the output signal of which causes switching of a switching transistor into conduction, thereby energizing a control winding of the solenoid valve.
10. A feed system as claimed in claim 9, wherein the thermo-sensor is formed by a temperature-dependent resistance, the resistivity of which significantly changes within a temperature range with narrow limits.
11. A feed system as claimed in claim 10, wherein the resistance is formed by a metal oxide resistance.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP2843335.4-13 | 1978-10-04 | ||
| DE2843335A DE2843335C2 (en) | 1978-10-04 | 1978-10-04 | Feed system for introducing water and / or water vapor into the intake path of an internal combustion engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1125601A true CA1125601A (en) | 1982-06-15 |
Family
ID=6051393
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA336,903A Expired CA1125601A (en) | 1978-10-04 | 1979-10-03 | Feed system for introducing water and/or water vapor into suction path of an internal combustion engine |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0009779B1 (en) |
| JP (1) | JPS5554657A (en) |
| AT (1) | ATE4469T1 (en) |
| CA (1) | CA1125601A (en) |
| DE (1) | DE2843335C2 (en) |
| ES (1) | ES484684A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4637351A (en) * | 1986-03-28 | 1987-01-20 | Ford Motor Company | System for removal of water from diesel fuel systems |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3170800D1 (en) * | 1980-02-21 | 1985-07-11 | Thomas Mark Cosway | System for adding liquid to the combustion air of an internal combustion engine |
| DE3405899A1 (en) * | 1984-02-18 | 1985-09-05 | Frank Dieter Dipl.-Phys. Dr. 8000 München Peschanel | Method and device for improving the power of combustion engines |
| DE3579456D1 (en) * | 1984-12-05 | 1990-10-04 | Murabito Luigi | METHOD FOR OPERATING AN INTERNAL COMBUSTION ENGINE AND INTERNAL COMBUSTION ENGINE. |
| DE3618700A1 (en) * | 1986-06-04 | 1987-12-10 | Murabito Luigi | METHOD AND ARRANGEMENT FOR BURNING A LIQUID OR GASEOUS FUEL IN A BURNING ROOM OF AN INTERNAL COMBUSTION ENGINE |
| DE3633949A1 (en) * | 1986-10-06 | 1988-04-07 | Lohberg Hans Martin | DEVICE FOR INSERTING WATER VAPOR INTO THE SUCTION PATH OF AN INTERNAL COMBUSTION ENGINE |
| US5125366A (en) * | 1990-10-11 | 1992-06-30 | Hobbs Cletus L | Water introduction in internal combustion engines |
| DE10007134A1 (en) * | 2000-02-17 | 2001-09-20 | Bayerische Motoren Werke Ag | Device for separating water from diesel fuel |
| AU2001289702A1 (en) * | 2000-09-30 | 2002-04-15 | Michael Hartkopf | Method and device for reducing fuel consumption |
| KR20180058488A (en) * | 2016-11-24 | 2018-06-01 | 현대자동차주식회사 | Water vapor supply apparatus for internal combustion engine |
| DE202018001792U1 (en) | 2018-04-10 | 2018-05-08 | Werner Lohberg | Catalyst of an internal combustion engine and its exhaust system |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3631843A (en) * | 1969-12-09 | 1972-01-04 | John O Yeiser | Fluid addition system for internal combustion engines |
| FR2146514A5 (en) * | 1971-07-16 | 1973-03-02 | Serruys Max | |
| JPS5025932A (en) * | 1973-07-10 | 1975-03-18 | ||
| FR2264182A1 (en) * | 1974-03-14 | 1975-10-10 | Penfentenyo Loic De | Fuel economiser for automobile engine - uses exhaust heat to evaporate water injected into inlet to carburettor |
| DE2535041A1 (en) * | 1975-08-06 | 1977-02-24 | Sen Josef Loos | Water vapour admixture to combustion engine fuel mixture - uses exhaust heat to evaporate water, admits vapour downstream of carburettor |
| DE2604050C3 (en) * | 1976-02-03 | 1982-03-11 | Werner 4790 Paderborn Lohberg | Feed system for an internal combustion engine to which the fuel-air mixture and water vapor can be fed |
| US4085719A (en) * | 1976-02-23 | 1978-04-25 | Ford Motor Company | Vapor pressure regulator for a vaporized liquid fuel system |
| US4027630A (en) * | 1976-03-22 | 1977-06-07 | Ford Motor Company | Vapor injection apparatus for an internal combustion engine |
| BE857723A (en) * | 1977-08-11 | 1977-12-01 | Delbruyere Lucien | THE ALMOST TOTAL ELIMINATION OF EXHAUST GASES FROM INTERNAL COMBUSTION ENGINES (MAINLY AUTOMOTIVE) AS WELL AS A REDUCTION IN FUEL CONSUMPTION IN THE SAME SYSTEM |
-
1978
- 1978-10-04 DE DE2843335A patent/DE2843335C2/en not_active Expired
-
1979
- 1979-09-28 AT AT79103687T patent/ATE4469T1/en not_active IP Right Cessation
- 1979-09-28 EP EP79103687A patent/EP0009779B1/en not_active Expired
- 1979-10-03 CA CA336,903A patent/CA1125601A/en not_active Expired
- 1979-10-03 ES ES484684A patent/ES484684A1/en not_active Expired
- 1979-10-04 JP JP12740579A patent/JPS5554657A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4637351A (en) * | 1986-03-28 | 1987-01-20 | Ford Motor Company | System for removal of water from diesel fuel systems |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0009779A1 (en) | 1980-04-16 |
| DE2843335C2 (en) | 1983-01-05 |
| JPS649463B2 (en) | 1989-02-17 |
| JPS5554657A (en) | 1980-04-22 |
| ATE4469T1 (en) | 1983-09-15 |
| ES484684A1 (en) | 1980-06-16 |
| EP0009779B1 (en) | 1983-08-17 |
| DE2843335A1 (en) | 1980-04-10 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |