DE19956378A1 - Introduction of liquids into gas fed to diesel reformer, e.g. for SOFC avoiding solids deposition, takes place in alternating stages of heating and liquid addition - Google Patents

Abstract

A gas (3) is heated (4) and vaporizes a subsequently-introduced liquid (5). Further heat supplied (8), vaporizes a second liquid introduction (9) downstream. The mixture enters the reaction chamber (1). Each vaporization may be partial. An Independent claim is included for plant carrying out the reforming process. This includes appropriate pipework and two heat exchangers (4, 8) followed by mixing nozzles (6, 10) introducing the liquids (5, 9). Preferred features: Heat (12) added before introduction into the reaction chamber is sufficient for vaporization of all liquids, and to reach the reforming temperature. Heating the gas, takes it above the boiling temperature of the first liquid introduction. Heat addition after the second liquid introduction, brings the mixture above the boiling temperature of the second introduction (9). Second and third introductions include atomization. The gas is air and/or steam. The first liquid (5) is a hydrocarbon (especially diesel) which is liquid at normal temperatures. The second liquid is water. In the plant, there is a further heat exchanger (12) near the second mixing nozzle. The mixing nozzles each have a constriction and a duct supplying the liquid. A plate heat exchanger (4, 8, 12) construction is used.

Description

The invention relates to a method for introduction of various gaseous and / or liquid be fuels for reforming a hydrocarbon substance in a reaction space, according to the generic term of claim 1 defined in more detail. Also be the invention meets a device for performing of the procedure.

The general state of the art knows different structures of nozzles or nozzle elements, which Introduce operating materials into a reaction space or dose.

Various such nozzles are from the one Spray technology of internal combustion engines known. For example, DE 38 00 711 U1 describes one Venturi mixer for mixing gas and air for the Use in an internal combustion engine.  

DE 27 39 206 A1 shows a device for entangling fuel / air mixture, with the aim of an ideal mixture of the two gaseous be to achieve fuels. In an optional setup a third gaseous com component can be mixed in.

The unpublished DE 199 29 945.5-41 shows a mixing nozzle, which two you independently components fed into a reak gate mixed together.

As part of a "Solid Oxide Fuelcell (SOFC)" distillery Stoffzellensystems is a structure in US 5,686,196 described in which a mixture of hydrogen and Diesel is produced, which is then replaced by a heat Metauscher and a desulfurization facility is tested. Before entering the actual refor Water is added to this mixture.

Especially with diesel, which is a mixture of many To use substances with different boiling points hen, there is the additional problem that it is insufficient evaporation, for example due to ge temperatures, to form a residue of high-boiling hydrocarbons. This return Stands then lead to impairment or something even clogging of the evaporator or heat build-up Schers or the catalyst structures in the reformer.

It is an object of the invention to provide a method for bring various gaseous and / or liquid fuel for reforming coal  by means of partial oxidation or autothermal mer reform to create the products the addition into the reaction space as a homogeneous mixture high temperature, and which the liquid fuels to their mostly largest Provide part in a gaseous phase can. It is also an object of the invention to provide a to provide direction for performing the method len.

According to the invention, this object is achieved by the method with the genann in the characterizing part of claim 1 characteristics solved.

The fact that according to the inventive method Feed, mixing and heating by the feed of thermal energy, the respective operating materials takes place in a multi-stage arrangement one after the other, can be an ideally heated, vaporized and good mixed mixture of the three operating materials Feed reaction space. Because the respective Operating fluid or the mixture of operating fluids the supply of the next fuel the supply of thermal energy has been heated can the supplied liquid operating fluid immediately after its introduction into the Ener material flow gie from the respective material flow and thereby evaporate at least partially. Through this multi-step Fige arrangement can be achieved that the correspond hydrocarbon, especially diesel, immediately to a very high temperature, for example with diesel wise at least 400 ° C is brought. This can be avoided that residues of high-boiling hydrocarbons, which comes in the  System contamination or even blockages could.

By introducing the respective liquid Be fuel, especially diesel and water, in the already very strongly warmed gas stream, can very high speed for feeding the resp gen operating materials in the desired combination realizations can be realized. This high speed validity of the procedure for the introduction of various gaseous and / or liquid supplies thus enables, in a particularly advantageous manner, that the system responded very quickly to requests such as e.g. B. load changes or the like to react ver like. The dynamic response behavior of a system to reform a hydrocarbon is by the inventive method for introducing ver different gaseous and / or liquid operation substances increased in an advantageous manner.

An apparatus for performing the method is by the characteristics of the characteristic part of An Proof 10 defined in more detail.

By building with two heat exchangers and little at least two each in the flow direction of the material flow because of the mixing nozzle arranged behind the heat exchangers sen is a very simple and compact implementation a device for performing the above described procedure.

Through this simple and very trouble-free Setup using simple heat exchangers and mixing nozzles a robust arrangement is achieved. The order  can in its dimension and in that contained in it Volume run so cheap and small that they have the particularly beneficial impact on the Dynamics of the overall system, which are characterized by the above mentioned procedures result in additional support can

In a particularly favorable embodiment of the inventive method and the associated Vor direction, which in the dependent claims 4 and 11 be is written, the respective liquid operation atomized when introduced into the material flow. This can be done, for example, by appropriate mixing nozzles sen, which is a narrowing for them by provide flowing material flow, the supply of the liquid substance to be introduced in the area of this The cross-section through which flow is narrowed.

This allows a very fine atomization of the led liquid operating fluid with an equal very good mixing of the two substances to reach. By the preheated gas flow the supplied liquid fuel can do a lot quickly and on a very short flow Path length to its at least approximately the largest part evaporate. This also results in more Advantages in terms of the dynamics of one with the procedure working overall system, as well as the most homogeneous mixing of the operating materials and the back steady supply of these operating materials into the reak tion room.

In principle, it is of course also considered the inventive method as well as the Vorrich  tion for the use of more than three operating materials to expand accordingly, for example easily realized through a modular structure leaves.

Further advantageous refinements and developments gene of the invention result from the further Un claims and from which based on the drawing following illustrated embodiment.

It shows:

Fig. 1 shows a construction for providing a Dreikom ponentengemischs for a reformer; and

Fig. 2 shows the area II in Fig. 1 in a more detailed representation.

Fig. 1 shows a schematic representation of the on device as it is provided for performing the method for introducing various gaseous and / or liquid fuels for reforming a hydrogen carbon in a reaction chamber 1 or a reformer 1 . The device can be used for various applications, but is particularly intended for the provision of operating materials in diesel reforming by means of partial oxidation or autothermal reforming for the production of hydrogen-containing gas for an on-board fuel cell system.

Via a first conduit element 2, a gaseous fuel 3, in particular air, a heat exchanger is supplied. 4 The heat exchanger 4 can be, for example, a cross-flow heat exchanger in plate construction, through which a heating medium flows according to the connection elements symbolized by the arrows 4 a, 4 b. In the Wärmetau shear 4 , the gaseous fuel 3 is heated to a temperature which is above the boiling temperature of a second, liquid fuel 5 . This liquid fuel 5 , here in particular diesel, is introduced into the material flow of the gaseous fuel 3 in a mixing nozzle 6 , which is arranged in the flow direction of the gaseous fuel 3 behind the heat exchanger 4 . Due to the corresponding structure of the mixing nozzle 6 , which will be discussed in more detail later, the liquid operating material 5 is distributed in the gas flow of the operating material 3 and can at least partially evaporate in the material flow through the energy supplied to the gaseous operating material 3 via the heat exchanger 4 .

At the mixing nozzle 6 another Lei line element 7 follows. In this line element 7 , for example, the mentioned evaporation of the liquid fuel 5 brought in can take place. In order to make the dynamics or the dynamic response behavior of the entire system as ideal as possible, the line element 7 is made as short as possible, which is made possible primarily by the construction of the mixing nozzle 6 , which will be described later.

After the short line element 7 , the material flow, which is now a mixture of the gaseous operating material 3 and the liquid operating medium 5 , which has meanwhile largely been evaporated at least to a large extent, enters a further heat exchanger 8 . This heat exchanger 8 is flowed through by a corresponding heating medium as indicated by the arrows 8 a, 8 b, which symbolize the connection elements of the heat exchanger 8 , indicated.

In the heat exchanger 8 there is again the supply of thermal energy to the mixture of the operating substances 3 and 5 . These are brought to a temperature which is above the boiling point of a third liquid fuel 9 to be introduced in the direction of flow after the heat exchanger 8 , here in particular water. In the heat exchanger 8 any remaining liquid portions of the second fuel 5 are finally evaporated in the material flow, so that the liquid fuel 9 is again introduced into a gas stream. The introduction of the operating medium 9 also takes place via a mixing nozzle 10 , which corresponds to the functional principle of the mixing nozzle 6 in its description, which will be described later. In principle, the same processes as in the mixing nozzle 6 and the line element 7 take place in the mixing nozzle 10 and the line element 11 adjoining it.

The reaction chamber 1 can then be connected directly to the line element 11 or, as shown in FIG. 1, a further, optional heat exchanger 12 can be used, which in turn is also a heating medium, characterized by the connecting elements 12 a, 12 b is flowed through, and in which the mixture of the operating materials 3 , 5 and 9 are further overheated. This optional heat exchanger 12 is then followed by a further line element 13 through which the heated mixture of the fuel 3 , 5 and 9 is introduced into the reaction chamber 1 .

In the reaction chamber 1 then takes place in a manner known per se, a partial oxidation or an autothermal reforming of the introduced hydrocarbon, in particular diesel. The resulting in the reforming by a water-gas shift reaction hydrogen-containing gas is then used for further use in a system for power generation, not shown here, such as. B. a fuel cell system.

To the hydrogen-containing gas from the reforming in the reaction chamber 1 to a temperature level well tolerated for the fuel cell, such as. B. bring about 80 ° C when using a PEM fuel cell, the gas is recooled accordingly. Reforming waste products, such as carbon monoxide or residues of hydrocarbon, are thermally decomposed or burned. The resulting heat, as well as the heat me, which is recovered as part of the recooling, can in turn be transferred to the heating medium and thus the two to three heat exchangers 4 , 8 , ( 12 ) in the device for introducing the operating materials are supplied. With sensible design of this heat feedback in the overall system, for. B. by several sub-circuits for the heating medium with the respective heat exchanger 4 , 8 ( 12 ) adapted temperature level, so a very high efficiency of the overall system can be achieved with very low thermal losses.

Fig. 2 now shows the structure of one for the multi-stage introduction of the operating material 3 , 5 , 9 Chen stage. The centerpiece here is the heat exchanger 8 , which is arranged between the two mixing nozzles 6 , 10 .

The basic sectional view through the metering stage according to II in Fig. 1 shows an inlet opening 14 through which the gaseous operating material 3 , which comes from the heat exchanger 4, gets into the mixing nozzle 6 and flows through it. The mixing nozzle 6 has the task of introducing the liquid component 5 into the material flow of the operating material 3 in the most finely atomized and evenly distributed form possible. In principle, all types of mixing nozzles 6 known per se which are capable of fulfilling this task are conceivable here.

Referring to FIG. 2, the mixing nozzle 6 is constructed as a kind of Venturi nozzle. The cross section to be flowed through by the gas flow of the operating material 3 has a cross-sectional constriction 15 . In the area of this cross-sectional constriction 15 , the liquid fuel 5 is supplied via a line element 16 . The supply of the operating fluid 5 can either be via a conveyor (not shown), gravity or self-priming by the negative pressure generated by the operating fluid 3 flowing through the mixing nozzle 6 due to the cross-sectional constriction 15 .

The liquid fuel 5 is entrained in the mixing nozzle 6 by the heated gas stream of the fuel 3 and the liquid fuel 5 is distributed very finely in the gas stream of the fuel 3rd

Due to the entrained thermal energy in the gas flow of the operating medium 3 , the liquid operating medium 5 evaporates in the mixing nozzle 6 and the line element 7 connected to it . In the heat exchanger 8 designed here as a plate heat exchanger, a mixture of the operating material 3 and the operating material 5 will occur, which already has the fuel 5 for its most part as a vaporized, gaseous operating material 5 .

The heat exchanger 8 is supplied with heating medium via the connection elements 8 a, 8 b. Here, the hot heating medium in the heat exchanger 8 passes through the connecting element 8 a and leaves it after it has delivered a large part of its thermal energy to the material flow from the supplies 3 and 5, b again through the connecting element. 8 The mixture of materials from the operating materials 3 and 5 is heated in the heat exchanger 8 and any droplets of the operating material 5 remaining in their liquid phase in the mixture are evaporated in the heat exchanger 8 .

When leaving the heat exchanger 8 , the gaseous stream of materials from the operating materials 3 and 5 enters the mixing nozzle 10 , which also narrows a cross-section 17 and a line element 18 to. Supply of the liquid fuel 9 in the region of this cross-sectional constriction 17 . The liquid fuel 9 supplied here is also finely distributed and can evaporate from the fuel 3 and 5 in the material flow due to the thermal energy supplied by the heat exchanger 8 . The mixture of the operating materials 3 , 5 , 9 then passes through the line element 11 to an outlet opening 19 and to the reaction space 1 .

The fuel 9 is in particular special water, which then in the mixing stage according to II in FIG. 1 directly, or via the further optional heat exchanger 12 subsequent reaction chamber I in the presence of a catalyst for a water-gas shift reaction provides, which enables the generation of the hydrogen-containing gas from the kohl hydrogen.

Due to the corresponding structure with the mixing nozzles 6 , 10 and the heat exchangers 4 , 8 , ( 12 ), the temperature required for the reforming of 800 to 1000 ° C. with ideally mixed feeds can be reacted or reacted to using the method Reach components.

In principle, it would also be conceivable to use water vapor or a mixture of water vapor and air in an embodiment of the invention as the first operating material 3 , so as to further improve the dynamic response behavior of the corresponding method for introducing the operating materials.

The mixing stage according to II in FIG. 1 can be used several times for more than three operating materials. Almost any number of these mixing stages can be arranged between the first heat exchanger 4 and the reaction space 1 or the heat exchanger 12 .

Claims (13)

1. A method for introducing various gaseous and / or liquid fuels for the reformation of a hydrocarbon in a reaction space, in particular in a reformer for sel reforming, the fuels being supplied with thermal energy, characterized in that a first, gaseous fuel ( 3 ) thermal energy is supplied, which is sufficient to at least partially evaporate a second, liquid fuel ( 5 ), which is subsequently introduced into the stream of the first fuel ( 3 ), after which the mixture of the first and second fuel ( 3 , 5 ) thermal energy is supplied, which is sufficient to evaporate a third, liquid operating fluid ( 9 ), which is subsequently introduced into the material flow from the first and second system operating fluid ( 3 , 5 ), at least partially, and then the mixture of the three operating materials ( 3 , 5 , 9 ) is added to the reaction room ( 1 ) is heard. 2. The method according to claim 1, characterized in that the mixture of the three operating materials ( 3 , 5 , 9 ) before entering the reaction chamber ( 1 ) thermal energy is supplied so that the mixture of the three operating materials ( 3 , 5 , 9 ) is evaporated at least approximately completely and is preheated at least to approximately the process temperature of the reforming. 3. The method according to claim 1 or 2, characterized in that by means of the supply of thermal energy to the first operating medium ( 3 ) this is brought to a temperature above the boiling point of the second operating fuel ( 5 ). 4. The method according to claim 1, 2 or 3, characterized in that by means of the supply of thermal energy after the introduction of the second fuel ( 5 ), the mixture of the first and second fuel ( 3 , 5 ) to a temperature above the boiling point of the third Operating fluid ( 9 ) is brought. 5. The method according to any one of claims 1 to 4, characterized in that the second and third operating material ( 5 , 9 ) are atomized stream when introduced into the respective gaseous substance. 6. The method according to any one of claims 1 to 5, characterized in that air is used as the first operating material ( 3 ). 7. The method according to any one of claims 1 to 5, characterized in that water vapor is used as the first operating material ( 3 ). 8. The method according to any one of claims 1 to 7, characterized in that a hydrocarbon which is liquid under normal conditions is used as the second operating material ( 5 ) and that water is used as the third operating material ( 9 ). 9. The method according to claim 8, characterized in that is used as a hydrocarbon diesel. 10. An apparatus for performing the method according to one of claims 1 to 9, with a reformer and with line elements for introducing the operating fluids, and a device for supplying thermal energy, characterized by at least two heat exchangers ( 4 , 8 ) and at least two in Flow direction of the material flow in each case behind the heat exchangers ( 4 , 8 ) arranged mixing nozzles ( 6 , 10 ) for introducing the operating fluids ( 5 , 9 ). 11. The device according to claim 10, characterized in that the second mixing nozzle ( 10 ) is followed by a further heat exchanger ( 12 ). 12. The apparatus according to claim 10 or 11, characterized in that the mixing nozzles ( 6 , 10 ) each have a constriction ( 15 , 17 ) of a cross section through which the material flow flows, the mixing nozzles ( 6 , 10 ) each having at least one line element ( 16 , 18 ) for supplying the operating material to be mixed ( 5 , 9 ) in the area of this constriction ( 15 , 17 ). 13. The apparatus of claim 10, 11 or 12, characterized in that the heat exchanger ( 4 , 8 , 12 ) are designed as a plate heat shear.