JP6602885B2 - Exhaust gas aftertreatment method and exhaust gas aftertreatment system - Google Patents

Description

  The present invention relates to an exhaust gas aftertreatment method. Furthermore, the present invention relates to an exhaust gas aftertreatment system.

  The role of exhaust gas aftertreatment plays an increasing role in the operation of internal combustion engines. Therefore, it is known from practice to guide the exhaust gas discharged from the internal combustion engine via a catalytic converter and / or particle filter for reducing the emission of exhaust gas. Furthermore, it is known from other exhaust gas aftertreatment systems to direct exhaust gas discharged from an internal combustion engine via a recovery section for heat recovery in order to make available the thermal energy contained in the exhaust gas. .

  Realizing the effective operation of an exhaust gas aftertreatment system with such a recovery section for the thermal energy of the exhaust gas is a major challenge and still offers significant improvement possibilities today. . Therefore, an exhaust gas post-treatment method and exhaust gas post-treatment that enable more effective recovery of thermal energy from exhaust gas in the area of the recovery section where sulfur compounds and particles and further constituents that adversely affect the treatment are removed from the exhaust gas. There is a need for a system. Exhaust gas conditioned for heat recovery must dominate all other subsequent processing steps of exhaust gas aftertreatment.

  From this point of view, the present invention is based on the object of creating a new type of exhaust gas aftertreatment method and exhaust gas aftertreatment system. This object is solved through the method according to claim 1. In the present invention, an absorbent is introduced into the exhaust gas downstream of the internal combustion engine with respect to the flow direction of the exhaust gas and mixed with the exhaust gas in order to adjust the exhaust gas for heat recovery and other processing steps of the exhaust gas post-treatment. Thereafter, the absorbent filled with sulfur compounds and further harmful substances, together with further particulate exhaust gas substances, is removed from the exhaust gas with the aid of a filtration device.

  The exhaust gas control method of the present invention comprises the steps of introducing an absorbent, reacting the absorbent with the above-mentioned pollutants contained in the exhaust gas, and an absorbent filled with the pollutants and further particulate exhaust gas substances. And the method can more effectively extract thermal energy from the exhaust gas that is made available in the region of the recovery section, and in all further processing steps of the exhaust gas aftertreatment, Further advantages can be provided. As a result, high overall efficiency can be realized in the power generation system or the propulsion system that is mounted on the internal combustion engine and includes the exhaust gas aftertreatment system.

  In an advantageous further development of the invention, the absorbent is introduced into the exhaust gas downstream of the internal combustion engine, mixed with the exhaust gas, and the temperature of the exhaust gas upon introduction of the absorbent is preferably higher than 250 ° C. Is preferably further configured to combine with further contaminants contained in the exhaust gas so as to reduce sulfur compounds by chemisorption. This makes it possible to adjust the exhaust gas particularly effectively for all further processing steps of the heat recovery and exhaust gas aftertreatment system. Preferably, the absorbent is introduced into the exhaust gas as a dry powder. By introducing the dried powder as an absorbent, the enthalpy that can be used within the range of heat recovery can be increased, so that the efficiency of the entire system can be increased. A further favorable effect is derived from the fact that technical processing and technical equipment for supplying and discharging the fluid can be omitted.

  In an advantageous further development of the invention, the temperature of the exhaust gas is higher than 250 ° C. even during desulfurization and dedusting in the exhaust gas cleaning filter.

  The exhaust gas aftertreatment system according to the present invention is defined in claim 9.

  Preferred further developments of the invention can be understood from the dependent claims and the detailed description of the invention. Exemplary embodiments of the present invention will be described in greater detail through the accompanying drawings, but are not intended to limit the present invention.

It is a block diagram of an exhaust gas aftertreatment system.

  The present invention relates to a method for exhaust gas aftertreatment of exhaust gas discharged from an internal combustion engine and an exhaust gas aftertreatment system for carrying out the method.

  FIG. 1 is a schematic system diagram including an internal combustion engine 10 and an exhaust gas aftertreatment system used to clean the exhaust gas 15 of the internal combustion engine 10. The exhaust gas aftertreatment system comprises a recovery section 11 for thermal energy in order to recover or generate the available thermal energy 11 contained in the exhaust gas 15. An example of the recovery section 11 is a heat exchanger.

  The present invention proposes to adjust the exhaust gas 15 to be pyrolyzed upstream of the separation section 11.

  By adjusting the exhaust gas 15 for heat recovery according to the invention, the absorbent 16 is introduced into the exhaust gas 15 downstream of the internal combustion engine 10 with respect to the flow direction of the exhaust gas, specifically with the assistance of the metering device 12. The The absorbent 16 introduced into the exhaust gas is mixed with the exhaust gas 15 in the region of the mixing section 14. Preferably, pollutants, in particular sulfur compounds and others, are removed from the exhaust gas in the filtration unit 13 after being combined with the absorbent in the region of the mixing section 14 located between the metering device 12 and the filtration unit 13. The

  The absorbent 16 is forcibly introduced into the exhaust gas 15 at an exhaust gas temperature higher than 250 ° C., specifically downstream of the internal combustion engine 10 and upstream of the filtration unit 13 and the recovery section 11. In this embodiment, the absorbent 16 is introduced into the exhaust gas 15 as a dry powder, specifically via a metering device 12 configured as a nozzle, for example.

  The absorbent 16 introduced into the exhaust gas 15 is preferably further combined with further pollutants that are contained in the exhaust gas and are problematic for subsequent processing steps so as to reduce at least sulfur compounds by chemisorption. It is configured. Subsequent processing steps are effective for both energy recovery and further exhaust gas aftertreatment purposes.

For example, a substance belonging to the sodium compound group or calcium compound group, which is in the form of ultrafine particles in a particularly advantageous embodiment of the above-described method, is used as the absorbent .

  As described above, the absorbent 16 introduced into the exhaust gas 15 is mixed with the exhaust gas 15, and most of the absorbent 16 is converted into the exhaust gas 15 in the region of the mixing section 14 and in the region of the metering device 12 and the filtration unit 13. Reacts with contained contaminants.

  Also as described above, thereafter, the absorbent filled with sulfur compounds and further pollutants and further particulate exhaust gas substances is removed from the exhaust gas with the aid of a filtration unit. The filter unit 13 is a filter for purifying exhaust gas, and uses a filter element made of, for example, a ceramic material or a metal material, which is adapted to a temperature higher than 250 ° C. Similarly, the exhaust gas temperature is higher than 250 ° C. during desulfurization and dedusting.

  When filtering with the filtration unit 13, the absorbent filled with pollutants and further particulate exhaust gas material is filtered from the exhaust gas and removed from the exhaust gas aftertreatment system.

  As a function of the absorbent used, the method still does not use up the contaminant binding capacity in the area of the filtration unit 13 and can be reintroduced into the exhaust gas 15 in the area of the metering system 12. Can be extended by a recirculation system.

  The present invention is used, for example, in a large internal combustion engine. Such large internal combustion engines include, for example, large internal combustion engines that operate on various types of fuel, such as liquid fuel or gaseous fuel, or coal or recycled fuel, and are used in power plants and ships.

  In the present invention, by adjusting the exhaust gas 15 discharged from the internal combustion engine 10 optimally, the resulting thermal energy can be recovered in the region of the recovery section 11. Furthermore, the advantageous features of the conditioned exhaust gas have an effective effect on the further possible steps of the exhaust gas aftertreatment method. For this purpose, the absorbent 16 is introduced into the exhaust gas 15, preferably as a dry powder, mixed with the exhaust gas 15, and then the filtration unit 13 removes the particulate material and the absorbent filled with contaminants. . The entire adjustment is forcibly performed at a temperature higher than 250 ° C. downstream of the internal combustion engine 10 and upstream of the components of the heat recovery section 11. This allows an optimal adjustment of the exhaust gas 15 for further steps where the heat recovery and exhaust gas aftertreatment methods can be implemented.

10 Internal combustion engine 11 Recovery section (separation section)
12 Metering device 13 Filtration unit 14 Mixing section 15 Exhaust gas 16 Absorbent

Claims (9)

A method for after-treatment of exhaust gas (15) discharged from an internal combustion engine, wherein the exhaust gas (15) is routed through a recovery section (11) for thermal energy of the exhaust gas In
In order to condition the exhaust gas (15) to recover heat and to enable further steps of the exhaust gas aftertreatment process, an absorbent (16) is connected to the internal combustion engine with respect to the flow direction of the exhaust gas. Downstream of (10) and upstream of the filtration unit (13) and the recovery section (11) at a temperature higher than 250 ° C. and introduced into the exhaust gas (15) and mixed with the exhaust gas (15) in a mixing section (14) is, the absorbent filled in subsequent contaminant (16), in the filtration unit (13) is separated along with other particulate exhaust gas substance, the exhaust gas (15), said recovery section (11) A method characterized by being pyrolyzed upstream. The absorbent (16) is introduced into the exhaust gas (15);
The method of claim 1, wherein the absorbent (16) functions to reduce sulfur compounds by chemisorption. The absorbent (16) is introduced into the exhaust gas (15);
3. A method according to claim 1 or 2, characterized in that the absorbent (16) functions to bind further pollutants which are contained in the exhaust gas and which are problematic for subsequent processing steps.   The method according to any one of claims 1 to 3, wherein the temperature of the exhaust gas when the absorbent (16) is introduced is higher than 250 ° C.   The method according to any one of claims 1 to 4, characterized in that the absorbent (16) is introduced into the exhaust gas (15) as a dry powder.   The method according to any one of claims 1 to 5, wherein the temperature of the exhaust gas is higher than 250 ° C even during desulfurization and dust removal.   The exhaust gas inside the filtration unit (13) is guided to be filtered through a filtration element made of, for example, a ceramic material or a metal material and adapted to high temperatures. The method as described in any one of -6. An exhaust gas aftertreatment system for exhaust gas aftertreatment of exhaust gas (15) discharged from an internal combustion engine (10), the exhaust gas aftertreatment having a recovery section (11) for thermal energy of the exhaust gas In the system,
A metering device (12) is positioned downstream of the internal combustion engine (10) with respect to the flow direction of the exhaust gas (15);
An absorbent (16) is disposed at the metering device (12) at a temperature higher than 250 ° C. downstream of the internal combustion engine (10) with respect to the flow direction of the exhaust gas and upstream of the filtration unit (13) and the recovery section (11 ). is introduced into the exhaust gas (15) through, subsequently, the exhaust gas containing said absorber is for the desulfurization and dedusted, is led through the filtration unit (13), the flue gas (15) The exhaust gas aftertreatment system is characterized in that it is pyrolyzed upstream of the recovery section (11).   9. The exhaust gas purification filter according to claim 8, characterized in that the filtration unit (13) is an exhaust gas purification filter comprising a filter element which can be adapted to high temperatures, for example a filter element made of ceramic material or metal material. Exhaust gas aftertreatment system.

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