Method for controlling a device for generating mechanical work
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GEA WESTFALIA SEPARATOR GROUP
- Filing Date
- 2024-11-08
- Publication Date
- 2026-06-19
Smart Images
Figure CN122249630A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for controlling equipment used to generate mechanical work by analyzing the fractions separated by centrifugation from contaminated wash water of an exhaust gas purification device. The method is particularly applicable to ships. Background Technology
[0002] In maritime transport, the importance of exhaust gas purification equipment, including so-called wet scrubbers, is increasing. Due to limited storage capacity, the scrubbing liquid must be purified and / or reused multiple times.
[0003] A method is known in which the washing liquid is guided in an open loop within an exhaust gas purification device. Measurements of PAK (polycyclic aromatic hydrocarbons) content are used to determine whether the purified washing water can be directly discharged outside the ship. pH, turbidity, and temperature are also monitored in the open loop.
[0004] A closed-loop circuit is also known in which the oil content and turbidity of water are measured. Currently, no inferences regarding the combustion efficiency of internal combustion engines have been drawn from such measurements.
[0005] Starting from this approach, the optimal operating point for combustion is first determined directly in the exhaust gas. While these measurements are technically feasible, they are very expensive. For example, mature measurement systems exist for sulfur oxides and nitrogen oxides. Here, the content of unburned fuel, lubricating oil, carbon black, and / or ash is not monitored or measured. Summary of the Invention
[0006] Based on the aforementioned prior art, the object of the present invention is to provide a method that allows for reliable setting of the optimal operating point for combustion. This optimal operating point can change in particular when fuel consumption increases or when the fuel type changes.
[0007] The present invention achieves the objective by providing a method having the features of claim 1.
[0008] The method according to the invention is used to control equipment for generating mechanical work. For example, the mechanical work can be used to drive the operation of a ship's propulsion system (e.g., a ship's propeller).
[0009] The equipment includes an internal combustion engine (e.g., an internal combustion motor) and exhaust gas purification equipment. The exhaust gas purification equipment includes a gas scrubber and a wash water purification device, the wash water purification device being used to purify contaminated wash water supplied by the gas scrubber. The wash water purification device includes a first purification stage having a centrifugal separator. The gas scrubber may also be located within equipment for exhaust gas recirculation.
[0010] The method is characterized by the following steps:
[0011] In the first step i), the exhaust gas generated by the internal combustion engine is purified while contaminated wash water is provided. This is carried out in the exhaust gas purification equipment, particularly in a gas scrubber constructed as a wet scrubber. The wash water is used as the medium for gas scrubbing.
[0012] In the second step ii), the wash water is purified by the centrifuge while providing multiple phases, one of which is purified wash water having a lower particle content compared to the supplied contaminated wash water.
[0013] This means that the purified wash water is less contaminated than the supplied wash water. However, it is not pure. Tiny particles of a specific size, particularly those smaller than a certain size, cannot be completely removed from the centrifuge.
[0014] In a particularly advantageous embodiment of the invention, this aspect, namely the residual particles and their concentration, is used to control the internal combustion engine.
[0015] In another step iii), at least one measurement is determined, which relates to the composition of one of the phases, particularly the purified wash water.
[0016] Preferably, multiple measurements of a phase are taken at staggered times. Therefore, the increase in component concentration can be determined. Here, the phase is the volume flowing out of the centrifuge.
[0017] Typically, the centrifuge operates continuously, causing the phase to also flow out at a continuous flow rate that may have fluctuating flow values.
[0018] However, information can also be obtained from the sludge phase or, optionally, the oil phase.
[0019] Finally, the operation of the internal combustion engine is controlled using the measured values.
[0020] Therefore, instead of using the measured values solely to determine the purification quality of the washing water purification equipment, as in the past, they are used to set the optimal operating point on the characteristic curve of the internal combustion engine. This method can include both active engine control and the creation of detailed operating instructions for the operator. Such operating instructions could, for example, be present in the inspection of fuel quality.
[0021] The preferred embodiment of the present invention is the technical solution of the dependent claims.
[0022] Advantageously, the operation of the internal combustion engine is controlled based on the determination of at least one or more measurements, the material properties of one phase in the phase and / or the concentration of a component of one phase in the phase, and the determined material properties and / or concentrations.
[0023] The material properties are physical material properties, which are preferably related to the composition of the phase and are particularly preferably selected from one of the following material properties:
[0024] - Viscosity,
[0025] -density,
[0026] - Thermal conductivity,
[0027] - Electrical conductivity.
[0028] Such parameters can be measured online. The established measurement method has relatively few interferences.
[0029] Furthermore, it is advantageous to determine the material properties and / or concentration of at least one component of the purified washing liquid, which is essentially water, in step iii). The washing liquid contains only components that cause minimal interference with the measurement. Therefore, this measurement is particularly free from interference.
[0030] Alternatively or additionally, in step iii), the material properties and / or concentration of at least one component in the sludge phase may be determined.
[0031] Similarly, alternatively or additionally, in step iii), the material properties and / or concentration of at least one component of the oil phase may be determined.
[0032] To analyze the oil phase, the centrifugal separator can be configured as a three-phase separator.
[0033] Advantageously, the centrifugal separator may have a disc assembly that improves separation and the disc assembly is disposed within a rotatably supported cylinder of the centrifugal separator.
[0034] The method may also include step v), in which the turbidity of the purified wash water is reduced to below 25 NTU in at least one second purification stage, based on the maximum limit value for external discharge.
[0035] Advantageously, the purified washing liquid can be directed to the outside of the vessel equipped with the device.
[0036] Furthermore advantageously, the measured concentration of the components of the purified washing water is the particle concentration in the purified washing liquid.
[0037] The centrifuge is preferably configured such that particles smaller than the limit size are not completely separated, the limit size being less than 500 nm, preferably less than 300 nm.
[0038] In addition, the device has a measurement and analysis processing unit for processing the measured values and for issuing control commands for adjusting the operation of the internal combustion engine, particularly the operating point.
[0039] Finally, the measurement can be performed online, with continuous control of the operation over the total operating time of the internal combustion engine. If the internal combustion engine, such as a ship's engine in a port, stops, the operation of the internal combustion engine and therefore its operating time cease. Continuous control of the operation allows for dynamic matching of the internal combustion engine's operation with changing conditions (e.g., higher power demands during high waves) and thus with changing fuel demands or other conditions. Attached Figure Description
[0040] Other advantages, features, and details of the invention will become apparent from the following description, in which various embodiments of the invention are explained in detail with the aid of the accompanying drawings. It will be apparent to those skilled in the art that the features disclosed in combination in the drawings, description, and claims are intended to be observed individually and combined into other meaningful combinations. In the drawings:
[0041] Figure 1 A schematic diagram showing a simplified flowchart of an implementation variation of the method according to the invention; and
[0042] Figure 2 The graphs show the particle concentration under different combustion conditions in an internal combustion engine. Detailed Implementation
[0043] A method for controlling an internal combustion engine 2 in a device 1 used to generate mechanical work. Advantageously, the device 1 can be used on a ship. The internal combustion engine can be a ship engine.
[0044] The exhaust gas flow X1 generated by the internal combustion engine 2 is supplied to the gas scrubber 4 of the exhaust gas purification device 3. The exhaust gas purification device 3 may optionally include a buffer tank 5 for temporarily storing contaminated scrubbing water X2.
[0045] Washing water X2 is formed by spraying washing water into the waste gas stream X1 during purification. The purified waste gas stream X3 exits the gas scrubber 4. Alternatively or additionally, the gas scrubber 4 can be constructed as another type of wet separator, or have such a wet separator.
[0046] The gas scrubber 4 also has an inlet for clean water. The inlet can be accessed via a water tank 6 and adjusted by a regulating mechanism 7.
[0047] Many components of the exhaust gas (carbon black, ash, unburned fuel, lubricating oil, etc.) are transferred to the washing water, which is then discharged from the gas scrubber 4 as contaminated washing water X2.
[0048] The contaminated wash water X2 can then be supplied to a buffer tank 5, which is an optional component of the exhaust gas purification device 3 and is also configured to receive the purified wash water.
[0049] A washing water purification device is connected to the exhaust gas purification device 2. The washing water purification device may have multiple purification stages for purifying the contaminated washing water X2.
[0050] In addition to particles, contaminated wash water can also contain oil (especially in the form of dispersed oil droplets).
[0051] The first purification stage includes a centrifugal separator 8, preferably a disc separator. The discs are preferably arranged in a disc group 12, which has a plurality of conical discs arranged parallel to each other.
[0052] EP2364760B1 describes the beneficial effects of disc separators in separating oil and particles as a common phase. However, it can be confirmed that even if such oil separation exists, it is not complete, but only a secondary effect observed.
[0053] To quantitatively separate oil as a separate phase from the wash water, a three-phase separator is preferred. This allows for separate testing of the oil as the separated phase.
[0054] The three-phase separator separates the contaminated wash water X2 into a light liquid phase (preferably an oil phase X4), a flowable sludge phase containing solids X5, and a purified wash water phase X6.
[0055] Unlike EP2364760B1, a particular advantage of using a disc separator as a three-phase separator in the current method according to the invention is that the use of discs allows for a relatively clear and easily verifiable oil phase and quantitative separation of particles up to a predetermined size range, preferably less than 500 nm.
[0056] More preferably, the centrifugal separator 8 has a rotatable support cylinder and a non-rotatable outer casing, which has an outlet pipe for the sludge phase X5.
[0057] The particle size distribution between the separated sludge phase X5 and the washing water phase X6 can be measured by selecting the rotation speed of the drum and, if necessary, by adjusting the spacing between the discs in the disc assembly.
[0058] Measurements of particle size distribution in the corresponding phase after the first purification stage can be performed via image analysis of a sample irradiated with a laser. Here, a small sample volume of water is guided through a measurement chamber and irradiated with a laser within the chamber. The measurement conditions are ambient pressure and room temperature. Diffraction patterns and motion can be analyzed for each particle.
[0059] Taking into account the common fluctuation range used in this measurement method, the particle concentration can be determined by a turbidimeter at normal pressure and temperature after sampling.
[0060] Here, the individual phases separated by the disc separator, especially the purified aqueous phase X6, can be easily and particularly with a small outlier rate.
[0061] Furthermore, the contaminated wash water X2 is transferred from the exhaust gas purification device 3 to the centrifugal separator 8 with the addition of other coagulants. Among a series of separation methods, such as EP3640444A1, it is preferable to add a coagulant to increase particle size for more effective centrifugal purification. This method is based on the objective of not separating particularly small particles in the first purification stage, but for analysis and setting up the original engine operation.
[0062] Coagulants, flocculants, or coagulant aids are substances that promote particle aggregation through adsorption, thereby increasing the size and weight of individual particles, which leads to better separation in a separator.
[0063] Additionally, the device for generating mechanical work may have a sampling unit for laboratory analysis of the oil quality of the separated light liquid phase X4 and / or a sensor 9 for online determination, preferably for real-time analysis of the oil quality of the separated light liquid phase X4. Here, this could be a turbidity sensor for determining the concentration of fine particles such as carbon black particles in the oil. Alternatively or additionally, it could be, for example, a viscosity sensor, such as a Coriolis flow meter. Viscosity provides information about the proportion of lubricating oil in the separated oil.
[0064] Alternatively or additionally, the complete apparatus for generating mechanical work may include a sampling unit for laboratory analysis to monitor the composition of the separated sludge phase X5 and / or sensors 10 for online determination, preferably for real-time analysis, of the composition of the separated sludge phase X5. This monitoring may be performed, for example, by a viscosity sensor or a density sensor. Changes in these parameters of the sludge phase indicate changes in the separation effect. This change allows for attribution, for example, unchanged separation performance, to altered operation of the internal combustion engine 2.
[0065] The separation performance does not need to remain constant. Therefore, it is possible to learn multiple operating modes while the internal combustion engine 2 is running at a constant speed. This allows for extrapolation of the measurements when the separation performance changes. The same applies to the analysis and processing of the other separated phases X4 and X6.
[0066] Additionally, the device for generating mechanical work may include a sampling unit for laboratory analysis of the water quality of the separated heavy liquid phase X6 and / or a sensor 11 for online determination, preferably real-time analysis of the water quality of the separated heavy liquid phase X6. Here, this could be a turbidimeter for determining the concentration of particles in the water. Alternatively or additionally, a sensor for measuring laser diffraction of particles may be used to determine the particle size distribution of particles in the heavy liquid phase. Alternatively or additionally, this could be, for example, a viscosity sensor or a Coriolis flow meter.
[0067] Alternatively or additionally, the PAK content in the heavy liquid phase can also be determined by sensor 11. This is preferably performed via online measurement. Commercially available sensors include, for example, the Endress+Hauser Memosens CFS51 or the Hach and Lange PAH500.
[0068] Additionally, the device for generating mechanical work has an adjustment mechanism 13 for guiding the purified heavy liquid phase X6 to the second purification stage 14.
[0069] The second purification stage 14 may include another centrifuge, a membrane filter, an adsorption filter with a suitable filter media, a stacked filter, etc. Unlike other separation variations, the use of an adsorption filter with activated carbon media is used not only to further reduce the NTU limit but also to completely decolorize yellow wash water in other cases. Stacked filters can also reduce the turbidity in the heavy liquid phase to 1 NTU to 35 NTU.
[0070] Starting from the limit of 25 NTU, the heavy liquid phase X6 can be removed, for example, by the double-purified liquid phase X7, to the outside of the ship. If the first purification stage has achieved sufficient purification, the heavy liquid phase X6 can be directly guided to the outside of the ship without passing through the second purification stage 14.
[0071] Before introduction, the quality of the water phase to be introduced can be tested, for example, by using the PAK and NTU content of residual oil, pH value and / or temperature.
[0072] If the purity is insufficient, the aqueous phase and the impurity phase X8 from the second purification stage 14 can be guided back to the buffer tank 5 through the adjustment mechanism.
[0073] Therefore, the wash water purification equipment ensures that the wash water meets the quality characteristics or limits confirmed by IMG before being introduced into marine waters. Previously, the focus was solely on purifying this water using very different methods (centrifuges, filters, membranes, etc.). Harmful substances formed during combustion in engines can vary in their form and proportion in exhaust gases.
[0074] The idea behind this invention is to, by means of analysis of the washing process, additionally obtain information about the combustion process in the engine and provide the operator with alerts regarding malfunctions, wear, or poor-quality fuel.
[0075] According to the modified purification scheme, the impurity components in the second purification stage 14, and the impurity phase X8 which is more contaminated than the supplied heavy liquid phase X6, can be returned to the buffer tank 5 through the return pipe.
[0076] An additional purification stage 15, such as a membrane filter or particulate filter with a replacement medium, can be provided on the return section to remove fine particles enriched in the impurity phase X8 from the impurity phase X8 and / or the heavy liquid phase X6. Thus, the composition of the returned phase changes again. Those skilled in the art will understand in the context of this invention that: Figure 1 Other regulating elements are usually installed at the pipe junctions in the system. Alternatively, other impurity phases X9 can be drawn from purification level 5 only.
[0077] The liquid can be ejected from the buffer tank 5 into the gas scrubber 4 or used in other ways and methods. The ejection is substantially related to the degree of contamination of the liquid.
[0078] After determining and / or monitoring individual parameters T1, T2 and / or T3 (such as viscosity, particle concentration and / or PAK (polycyclic aromatic hydrocarbon) value) related to the components of the corresponding phases X4, X5 or X6, such parameters are used to control the operation of the internal combustion engine 2.
[0079] Here, one or more measured parameters T1, T2 and / or T3 are transmitted to the measurement and / or analysis processing unit 16, which issues a control command S1 based on one or more measured parameters, the control command being used to control the operation of the internal combustion engine 2.
[0080] Therefore, combustion can be optimized, especially in low-harmful-substance operating modes, or, for example, adapted to fuel when fuel changes.
[0081] Here, the following characteristic is utilized: the first purification by the centrifugal separator is incomplete, which makes it possible, in particular, to use the measured value of the heavy liquid phase X6 to control the operation of the internal combustion engine 2.
[0082] If, for example, the concentration of particles in such a heavy liquid phase increases, this is crucial for the incomplete combustion of fuel in the internal combustion engine.
[0083] The following analysis can be attributed to the following qualitative characteristics of the operation of the internal combustion engine:
[0084] a) Particulate concentration measurement => Increased particulate matter < Limit value, e.g., 300nm = poor combustion in the engine, inferior fuel.
[0085] b) Oil content in water,
[0086] I. Exceeding the limit indicates poor combustion in the engine.
[0087] II. Lubricating oil detection => Excessive lubricating oil input, wear.
[0088] III. Fuel detected => Insufficient air intake, inadequate fuel atomization
[0089] c) PAK content => Increase => indicates incomplete combustion, poor fuel quality, and insufficient air intake.
[0090] Regarding the detection of lubricating oil or fuel: Commercially available oil-in-water sensors exist, and these sensors can be calibrated for different types of substances. Therefore, they can also be used for fuels and lubricating oils. In this regard, the detection of these substances can be achieved.
[0091] In contrast to other purification technologies, in centrifugal separator 8, the separation effect decreases as the particle size decreases.
[0092] Therefore, measurements can be taken after centrifugal separator 8 and before the second purification stage 14.
[0093] Purification in the second purification stage can be carried out in different ways and by different methods, such as by means of membrane filtration, by other filters, by adding a coagulant and then centrifugation.
[0094] In the second purification step, the wash water is completely purified. Conversely, centrifuge 8 allows only the particles that must be monitored to pass through. Particle measurement before the purification equipment (in the raw water) is technically almost impossible due to the high level of contamination.
[0095] As a three-phase separator, the centrifuge also provides the possibility of more accurately testing the separated light phases (such as oil and fuel). Here, harmful substances are significantly concentrated and can be detected more easily, both quantitatively and qualitatively.
[0096] However, the invention can also be carried out in a two-phase separator in a secondary embodiment.
[0097] The method can be applied to the washing water in sulfur oxide scrubbing towers (desulfurization) and nitrogen oxide scrubbing towers (reducing nitrogen oxides by drawing back waste gas).
[0098] Unexpectedly, within a large number of experiments, it was found that small particles with an average size preferably less than 500 nm, and particularly preferably less than 300 nm, which cannot be separated by a centrifugal separator, are strongly concentrated at non-optimal operating points during engine operation.
[0099] This is thanks to Figure 2 explain.
[0100] The graph illustrates engine operation with heavy oil. The heavy oil comprises 1.34% by weight of ammonium sulfide. The load points are 20 kW and 60 kW for the same operating time.
[0101] Measurement curve A shows the change in particulate concentration under optimal combustion conditions.
[0102] Measurement curve B shows the change in particle concentration during incomplete combustion.
[0103] Measurement curve C, between measurement curves A and B, shows an increase in particle size with respect to the average particle diameter. It can be observed that the change in particle concentration is primarily observed with small particles (10 nm to 200 nm), while the non-significant increase in concentration in the wash water with larger particles is observed under suboptimal combustion conditions.
[0104] Depend on Figure 2 It can be seen that the particulate concentration of the internal combustion engine increases significantly when it is not operating optimally.
[0105] If such an increase is detected, the operating point of the internal combustion engine can be readjusted for such a long period of time according to the invention, until the increase decreases or tends to level off.
[0106] Explanation of reference numerals in the attached diagram
[0107] 1. Equipment used to generate mechanical work
[0108] 2 Internal Combustion Engines
[0109] 3. Waste gas purification equipment
[0110] 4 Gas Scrubber
[0111] 5 buffer boxes
[0112] 6 water storage tanks
[0113] 7 Adjustment Mechanism
[0114] 8 centrifuges
[0115] 9 sensors
[0116] 10 sensors
[0117] 11 sensors
[0118] 12-disc set
[0119] 13 regulating mechanisms
[0120] 14 Second purification level
[0121] 15 Other purification levels
[0122] 16 Measurement and Analysis Processing Units
[0123] X1 exhaust gas
[0124] X2 Washing Water
[0125] X3 purified exhaust gas
[0126] X4 Oil Phase
[0127] X5 sludge phase
[0128] X6 Purified Wash Water Phase
[0129] X8 impurity phase
[0130] X9 impurity phase
[0131] T1 measurement signal
[0132] T2 measurement signal
[0133] T3 measurement signal
[0134] S1 control command
Claims
1. A method for controlling an apparatus (1) for generating mechanical work, said apparatus (1) comprising: Internal combustion engine (2), exhaust gas purification equipment (3), the exhaust gas purification equipment including a gas scrubber (4) and a washing water purification equipment, the washing water purification equipment including a first purification stage with a centrifugal separator (8), The method is characterized by comprising the following steps: i) Purify the exhaust gas (X1) generated by the internal combustion engine (2) while providing contaminated washing water (X2); ii) The washing water (X2) is purified by the centrifuge (8) while providing multiple phases (X4, X5, X6), one of which includes the purified washing water (X2) having a lower particle content compared to the supplied contaminated washing water (X2); iii) Determine at least one measurement (T1, T2, T3) that is related to the composition of at least one of the phases (X4, X5, X6); iv) Adjust the operation of the internal combustion engine (2) using the measured values (T1, T2, T3).
2. The method according to claim 1, characterized in that, The at least one or more measurement values are determined, and the material properties of one of the phases (X4, X5, X6) and / or the concentration of a component of one of the phases (X4, X5, X6) are determined by means of the measurement values, and the operation of the internal combustion engine (2) is controlled according to the determined material properties and / or concentrations.
3. The method according to claim 2, characterized in that, The material properties are physical material properties, which are preferably related to the composition of the phases (X4, X5, X6) and are particularly preferably selected from, for example, one of the following material properties: - Viscosity, -density, - Thermal conductivity, - Electrical conductivity.
4. The method according to any one of the preceding claims, characterized in that, In step iii), the material properties and / or concentration of at least one component of the purified wash water (X6) are determined.
5. The method according to any one of the preceding claims, characterized in that, In step iii), the material properties and / or concentration of at least one component in the sludge phase (X5) are determined.
6. The method according to any one of the preceding claims, characterized in that, In step iii), the material properties and / or concentration of at least one component of the oil phase (X4) are determined.
7. The method according to any one of the preceding claims, characterized in that, The centrifugal separator (8) is constructed as a three-phase separator.
8. The method according to any one of the preceding claims, characterized in that, The centrifugal separator (8) has a disc assembly (12) disposed within a rotatable support cylinder of the centrifugal separator (8).
9. The method according to any one of the preceding claims, characterized in that, The method includes step v), in which the purified wash water (X6) is reduced to a particulate content of less than 25 NTU in at least one second purification stage (14).
10. The method according to any one of the preceding claims, characterized in that, The purified washing water (X6) is directed to the outside of the vessel equipped with the device (1).
11. The method according to any one of the preceding claims, characterized in that, The concentration is the concentration of particles in the purified wash water (X6) downstream of the centrifuge (8) and upstream of the second purification stage (14).
12. The method according to any one of the preceding claims, characterized in that, The centrifuge (8) is configured to not completely separate particles smaller than the limit size, which is less than 500 nm, preferably less than 300 nm.
13. The method according to any one of the preceding claims, characterized in that, The device (1) has a measurement and analysis processing unit (16) for processing the measured values (T1, T2, T3) and for issuing control commands (S1) for regulating the operation of the internal combustion engine (2), particularly the operating point.
14. The method according to any one of the preceding claims, characterized in that, The determination of the measured values (T1, T2, T3) is carried out in online measurement, and the operation is continuously controlled over the total running time of the internal combustion engine (2).