Patent Application
20110094492
The subject-matter of the invention is a device for feeding water steam via a heat exchanger in a combustion chamber and a method for using said device.
It is known to inject water into the combustion chambers in a thermal engine. The injection of water into the combustion chamber of diesel engines produces, for example, the reduction of nitrogen oxides and of the black smoke. Furthermore, it is known that the feeding of water steam into the combustion chamber can increase the energy efficiency of the fuels used.
The problem of the present invention is to make available a particularly advantageous embodiment of the generation of heated water steam to be fed into the combustion chamber of a thermal engine.
The problem is solved by the subject-matter of the independent claims. Advantageous embodiments are the subject-matter of the sub-claims or are described below.
Combustion chambers such as those suitable for the performance of the invention can be part of thermal engines or also of heating burners. Thermal engines in the sense of the invention are reciprocating piston engines, such as for example two-stroke, spark-ignition and/or diesel engines. Apart from these, however, rotary piston engines and gas turbines are also suitable. Such thermal engines or heating burners comprise a fuel and combustion-air supply (intake air) as well as an exhaust for hot combustion gases (exhaust gases).
Suitable fuels are substances oxidisable with heat gain. Examples are hydrocarbons and their derivatives. Suitable derivatives are plant oils, biodiesels, such as esters of saturated or unsaturated fatty acids, in particular methyl ester and/or ethyl ester, or alcohols, ethanol, propanol or methanol.
A multi-wall tube heat exchanger or a multi-wall spiral heat exchanger is part of the device according to the invention.
According to one embodiment (multi-wall tube heat exchanger), the heat exchanger comprises an inner tube, an inner jacket tube and outer jacket tube. The inner jacket shell is formed by the inner tube and the inner jacket tube, the outer jacket shell by the inner and outer jacket tube. The hot exhaust gas of the thermal engine flows in each case through the inner tube (first jacket shell) and the outer jacket shell of the tube heat exchanger. The outer jacket shell is bounded gas-tight to the exterior by the outer jacket tube. The water steam-containing, gaseous medium is fed in the inner jacket shell, on the one hand bounded gas-tight by the inner tube, on the other hand bounded gas-tight by the inner jacket tube, so that said medium is sucked in by the intake connection piece of the thermal engine. Hot exhaust gas preferably flows in an equi-directional flow through inner tube and outer jacket tube and the water steam-containing, gaseous medium is introduced in a counter-flow.
The water steam-containing, gaseous medium is preferably fed via an inlet with a larger cross-section than the inner jacket tube tangentially and in particular at an angle of 45 to 135° to the flow direction in the heat exchanger, in relation to the operating direction of the heat exchanger, and is carried away independently thereof tangentially via a larger cross-section. The exhaust gas is also preferably fed and/or carried away tangentially, in each case preferably via a larger inlet cross-section.
A spiral heat exchanger is also suitable. The latter comprises two jacket shells wound into each other. The production takes place for example by the fact that an elongated rectangular sheet metal is folded together roughly at half the length. It is then wound up starting from the middle to form a spiral, as a result of which there arise two separate jacket shells spaced apart from one another, whereof one is supplied with exhaust gas and the other with the water steam-containing, gaseous medium. The supply takes place on the one hand via the front face and on the other hand via the open-lying outer jacket shell. The cold medium (the water steam-containing, gaseous medium) is preferably fed externally and the hot medium (exhaust gas) internally. In the spiral heat exchanger, as in the tube heat exchanger, the cold medium is brought into contact on both sides with two hot contact surfaces in which exhaust gas is conveyed. It is particularly advantageous if the winding in the spiral heat exchanger takes place in such a way that, in the direction of the outlet of the heat exchanger, the water steam-containing, gaseous medium is compressed by the smaller cross-sectional width of the jacket shell for the hot medium.
The exhaust gas heats the water steam-containing, gaseous medium in the heat exchanger to a temperature of over 550° C., preferably 600 to 900° C., in particular 650 to 800° C.
It is particularly preferable if the cyclical turbulence created by the tangential supply with a larger cross-section is contra-rotating. The exhaust gas is preferably conveyed for example rotating clockwise in the heat exchanger and the water steam-containing, gaseous medium rotating anticlockwise (or vice versa).
When one considers that, for example in a spark-ignition engine, the gas has an outflow rate of up to approx. 2000 km/h when the outlet valve is opened and these gases are conveyed directly in tangential paths at the exhaust gas flange, it is possible to imagine the enormous cyclical turbulence.
The exhaust gas-conveying jacket shell(s) enclose(s) the inner jacket shell for both types of heat exchanger with the water steam-containing, gaseous medium from both sides, said inner jacket shell lying in the middle and being connected to the intake side of the combustion chamber. The heat exchange takes place particularly effectively via both exchange surfaces.
The supply of the water steam-containing, gaseous medium to the engine takes place in the intake region for the combustion air, advantageously through a Venturi flange with slots at a narrow point, in particular at the narrowest point. Here, other fuels can advantageously also be fed at the same time with the water steam-containing, gaseous medium.
The exchange surfaces of the jacket shells advantageously comprise, on the outer and/or the inner exchange surfaces, unevennesses in the form of recesses and/or bulges in arbitrary geometrical shapes, for example peripheral beads, S-shaped, rectilinear, helical recesses, cylindrical, conical, cylindrical with conical countersinking, spherical or hemispherical. The recesses and/or bulges introduced into the material serve to enlarge the surface for the heat exchange, but also have a fluid-related significance, because they are intended to guide the gas flows in such a way that the latter become turbulent, preferably concentrically about the axis of the heat exchanger. Micro-eddy formations can also occur here, such as is produced for example by the nanoperforation of the material.
A micro- or nano-perforation is particularly well suited. Micro- or nano-perforations can be introduced into the material by laser treatment. The heat exchanger and its walls are preferably produced from special steel, glass, aluminium, brass and/or copper.
The water steam-containing, gaseous medium is therefore exposed to great heat and is heated, the intake air supply at the same time generating an under-pressure, as a result of which the boiling point is lowered. Furthermore, the gas mixture experiences a marked shearing action due to the tangential inflows, combined, as the case may be, with the material processing described above.
Without wishing to be bound to the theory, it is further assumed that, as a result of the contra-rotation of the hot and cold gas flows, electrostatic/electromagnetic fields are generated which have an ionising and/or polarising effect.
Moreover, the tangentially guided, turbulent air flows have a self-cleaning effect and counteract clogging of the heat exchanger.
The water steam-containing, gaseous medium can for example be obtained by condensation from water which arises during combustion in the rear region shortly before the outlet of the exhaust system. For this purpose, the exhaust gas can be cooled, for example, by a multi-stage baffle plate labyrinth in order to condense water, and the water is conveyed by means of a fluid pump following the evaporator or an intermediate water storage tank. As a result, the device becomes independent of the supply of water from the exterior. The excess steam-distilled and purified water can be discharged into the environment without problem.
The further component part of the invention is the treatment of the employed waters, optionally also other employed fluids or gases (e.g. hydrocarbons), with permanent magnetic fields and/or electromagnetic fields.
For this purpose, the fluids and vapours are conveyed (separated or jointly) during the operation within the circuit through gaps, channels and/or tubes by permanent magnets or electromagnets (with up to 14,000 Gauss), as a result of which not only is the cluster formation broken up and the surface tension reduced, but also the molecules are polarised.
The fluids or gases, in particular the water or the water steam, are preferably subjected to a magnetic field of 8,000 to 14,000 Gauss.
According to another embodiment of the invention, the water steam-containing, gaseous medium is further provided with substances oxidisable with an energy gain as further fuels. These are in particular hydrocarbons. The evaporation products are converted from the liquid state into the vapour state, preferably using the heat from the hot exhaust gases. The proportion of water in such a gas mixture can vary depending on the quality of the fuels. Good results are obtained with a petrol mixture with a petrol to water ratio (in each case volume related to the liquid state) of 10 to 30 up to 80 to 70 vol. %, in particular 20 to 80 vol. %. Residues can also be used as further fuels, such as used petroleum spirits, frying fats, plant oils or animal fats. Surprisingly, even sulphuric acid can be added (e.g. sulphuric acid/water: 30 to 70 vol. %).
Without wishing to be bound to the theory, it is assumed that the further fuels are cracked in the heat exchanger into higher-grade, more readily combustible fuel gases. It is therefore possible, for example, to operate a spark-ignition 4-stroke petrol engine trouble-free and cleanly with diesel, fuel oil or heavy oil. The proportion of water in the water steam-containing, gaseous medium fed to the heat exchanger then advantageously amounts to 50 or 30 vol. %.
As a result of the heat treatment, optionally also by means of catalytic or other interactions, it is further assumed that the water steam is split partially into hydrogen and oxygen. If hydrocarbon compounds are added, it is to be assumed that further reactions take place which lead to the formation of energy-containing substances, such as for example the formation of carbon monoxide, which is converted completely into carbon dioxide in the engine. In this way, fuels not readily accessible to combustion in the engine can be refined.
It is therefore possible to feed the necessary fuels to the engine either conventionally, partially or completely and therefore exclusively via the heat exchanger.
Water and further fuels can also be injected into the heat exchanger and do not necessarily have to be evaporated beforehand, whereby here an atomisation preferably takes place and the heat exchanger brings about the evaporation.
It is however preferable for the evaporation to take place separately and for the further fuels and/or the water to be heated by exhaust gas heat or residual heat in evaporators provided for the purpose and to be carried away in vapour form, if need be also via a heated supply vessel for the gases, said supply vessel being provided for the purpose and being under pressure.
The hot exhaust gases are preferably fed to the heat exchanger immediately after leaving the combustion chamber. The exhaust gas manifold can for example be part of the heat exchanger.
To advantage, the water is used as distilled water or water demineralised by osmosis or ion exchanger. It is also possible partially to split the water by electrolysis in order to use hydrogen-rich water as the water steam-containing, gaseous medium and to introduce the same into the heat exchanger.
It is particularly preferable if the conveyed fluids and gases are conveyed wherever possible in a turbulent manner. For this purpose, suitably designed guide vanes can be fitted in the tubes or lines, which comprise tangential baffle faces.
The invention is explained by way of example by the figures. In the figures:
Heat exchanger 1 comprises an inner tube 2, an inner jacket tube 3 and outer jacket tube 4. Inner jacket shell 6 is formed by inner tube 2, which surrounds first jacket shell 5, and inner jacket tube 3, outer jacket shell 7 being formed by inner jacket tube 3 and outer jacket tube 4.
Hot exhaust gas 10 of the thermal engine flows in each case in an equi-direction flow through first jacket shell 5 (in this case a full-hollow body, but not necessarily) and outer jacket shell 7 of the tube heat exchanger. In the case of the opposite operating direction, water-containing medium 11a is conveyed in inner jacket shell 6.
Inlet 8a, 8b, 8c and outlet 9a, 9b, 9c of the heat exchanger each have a larger cross-section than the respective jacket layer. Exhaust gas 10 and water-containing medium 11a are fed and carried away tangentially with respect to operating direction 12 of the heat exchanger.
The effect of the larger cross-sections on the inlet side and the tangential introduction is that exhaust gas and water-containing medium in the jacket shells circulate about the axis of the heat exchanger, preferably with the opposite direction of rotation with respect to the pair exhaust gas—water-containing medium.
Intensely superheated water steam 11b exits. The surface of the heat exchanger faces is provided with cutouts 12.
An evaporator for hydrocarbons 13, in the present case petrol as the fuel, and an evaporator for water 14 are provided. The vapour rates are mixed or metered by control valves 15, 16, 17 and transferred into heat exchanger 1 according to
The gas supply is brought about by the engine, which acts like a gas pump. The effect of the gas flow is that ambient air is fed via pipes 18 and the latter bubbles through the liquid phase at the outlet of the pipes.
The gas flows/vapours fed in the correct mixing ratio are heat-treated in heat exchanger 1 in order to be fed to the combustion chamber of engine 19 via intake manifold 20.
The gas supply rate or the speed can be regulated by means of controller 21. Controller 22 further makes available (if necessary) additional fresh air and/or fuel gases immediately before the entry to the engine (in a controllable manner).
Heat exchanger 1 is heated with hot exhaust gas via exhaust gas manifold 23. The exhaust gas flows through the heat exchanger in a counter-flow relative to the water steam- and fuel-containing medium.
It is of course also possible to dispense with the evaporator for hydrocarbons 13 and to feed the fuels solely in a conventional manner, such as takes place for example in spark-ignition or diesel engines, and/or additionally into the engine.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2008 018 664.3 | Apr 2008 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/DE09/00474 | 4/9/2009 | WO | 00 | 12/30/2010 |
