JP2012137092A - Large-sized two-cycle diesel engine equipped with exhaust gas re-circulation control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust gas re-circulation system which is used in a cross-head type large-sized supercharged two-cycle diesel engine.SOLUTION: At least a part of an exhaust gas re-circulation passage has at least two parallel rows, each row forms a passage, and in each row, there is arranged at least one of a wet scrubber for treating or controlling a re-circulation exhaust gas, a dry filter, a cooler, a condenser, a heater, a mist caster, a blower, a compressor and a valve. By operating one or more rows, an arbitrary desired capacity can be obtained in the re-circulation exhaust gas system.

Description

  TECHNICAL FIELD The present invention relates to a crosshead type large turbocharged two-cycle diesel engine equipped with an exhaust gas purification system, and specifically to a crosshead type large two-cycle diesel engine equipped with an exhaust gas recirculation system.

  A crosshead large two-cycle engine is typically used as a propulsion system for large ships and as a main engine of a power plant. In these institutions, it is becoming increasingly difficult to meet emission requirements, particularly with respect to nitric oxide (NOx) levels.

  Exhaust gas recirculation (EGR) is a technique known to help reduce NOx emissions in diesel engines. To date, however, there are no commercial large two-cycle diesel engines that use an exhaust gas recirculation system. The reason is that it has become clear that the implementation of an exhaust gas recirculation system in a large two-cycle diesel engine is a serious challenge. One reason that the implementation of exhaust gas recirculation systems in large two-cycle diesel engines has proved to be a major challenge is the fact that these engines typically operate on heavy oils with high sulfur content Is mentioned. For this reason, the sulfur content of the exhaust gas is higher than that of smaller diesel engines operating with fuel oil that has low or no sulfur content. Due to the high concentration of sulfur, the purification methods and devices that can be selected are very limited, and most of these methods and devices are at the sulfur and sulfuric acid levels present in the exhaust gas of large two-stroke diesel engines. I can't stand it.

  One of the exhaust gas purification methods capable of withstanding the high sulfur level of a large two-cycle diesel engine is wet cleaning. In this method, the exhaust gas passes through a so-called wet cleaning device (wet scrubber) that uses water as a cleaning liquid.

However, the exhaust gas recirculation system of a large turbocharged two-cycle diesel engine equipped with a wet exhaust gas scrubber for purifying the recirculated exhaust gas is used for cleaning because evaporated water flows downstream together with the cleaning gas. Consumes a large amount of water. For example, if a MAN B & W type 7S50MC engine is operated to add 20% EGR (ie, 20% of the scavenging gas is made up of recirculated gas from the exhaust), the amount of water will be the amount of scrubbed gas 13% of the mass flow rate of, for example, 2.1 m ³ / h. Although fresh water is valuable for ocean-going vessels, it is clear that a significant amount of fresh water is needed.

  Another challenge is the enormous amount of power required to direct the recirculated exhaust gas from the exhaust receiver to the scavenging airflow. In large two-cycle diesel engines, the scavenging pressure is typically about 0.3 bar above the exhaust receiver pressure. Thus, a blower or other means is required to push the recirculated exhaust gas from the exhaust receiver to the scavenging system. For a 12 or 14 cylinder type two-cycle diesel engine with a large bore, such as a MAN B & W 12K98MC-C engine, the power required to drive such a blower can be close to 5 MW. This represents a significant amount of energy used in the exhaust gas purification system. Furthermore, such an electric motor that drives a blower that requires a large amount of electric power is extremely expensive.

  The costs associated with large diesel engine exhaust gas recirculation system machinery, such as wet scrubbers and blowers, are substantial due to the large size of these parts. Some of these parts, such as electric motors, are so large that their price increases exponentially with size, and the price of these large electric motors is extremely important. Yes.

  Document DE 1980618 A1 discloses a large two-cycle diesel engine with an exhaust gas recirculation system. Each cylinder of the engine has three outlets for exhaust gas. Exhaust gas from one of the three outlets is collected and reused for scavenging. In one embodiment of a two-cycle engine, soot particles from the recycled exhaust gas by a dry filter before passing through a cooler and a blower that propels the recycled exhaust gas cooled for reuse to scavenge. Remove.

  The disclosed two-cycle diesel engine can recirculate a portion of the exhaust gas, but if there is a significant change in the amount of exhaust gas, for example due to large fluctuations in the engine load, the exhaust gas Can not meet the requirements of recirculation.

DE1980618A1

  From such a background, an object of the present invention is to provide a large turbocharged two-cycle combustion engine equipped with an exhaust gas recirculation system that is commercially feasible and highly flexible.

  The purpose is to recirculate at least a portion of the exhaust gas into the scavenging path, a plurality of cylinders each coupled to the exhaust receiver, a scavenging path having a scavenging receiver connected to each of the cylinders. The exhaust gas recirculation flow path of the crosshead type large two-cycle combustion engine, wherein at least a part of the exhaust gas recirculation flow path includes at least two columns in parallel, This is accomplished by providing a crosshead large two-cycle combustion engine that forms a path and includes at least one device for processing or controlling the recirculated exhaust gas.

  By employing at least two parallel rows, each forming a flow path, with parallel rows comprising at least one device for treating or controlling the recirculated exhaust gas in the exhaust gas recirculation system A very flexible, highly useful and more economical operating technique is provided for exhaust gas recirculation systems in combustion engines. This is due to the fact that it is possible to use smaller and cheaper components in the exhaust gas recirculation system than was possible in the exhaust gas recirculation system conventionally used. Furthermore, the exhaust gas recirculation system can be more easily and better adapted to partial load conditions. The exhaust gas recirculation system provided by the present invention can be operated and controlled very accurately, thereby making the operation of the combustion engine very economical and stable.

  The size of individual devices for treating or controlling the recirculated exhaust gas may be small. This is because more devices can be used in parallel in a parallel row, and by combining them, the same effect as that achieved with large devices can be achieved. is there. This also gives the option to use industry standard parts equipment, parts equipment that is not too expensive. Furthermore, improved stability and controllability of the device can be obtained by appropriate selection of operating conditions. Moreover, since it is possible to maintain individual devices in a relatively high load state even during partial engine loads, the performance of individual devices can be increased and the efficiency can be optimized. . For example, a device such as a blower has a relatively narrow area for operating with high efficiency. Therefore, when there is only one blower having a size suitable for an engine operating at a high load, the operating efficiency is reduced when the engine operates at a low load.

  The small size of each device makes it easy to place the device in the engine system because of the small installation space, which increases the flexibility. Specifically, it becomes easy to equip an existing engine not designed for EGR with an EGR system (such an engine does not have a space for installing a conventional EGR system).

  Since this process stage actually regenerates fresh water (in the cooler), it effectively consumes no fresh water, and conversely, this process stage produces fresh water.

  Although the columns have been described as parallel columns, these columns need not be literally parallel. A parallel sequence should be interpreted as a “process sequence” in which processes or processes are performed in parallel. The appearance of the rows is like engine parts such as pipelines, valves, and exhaust gas treatment devices.

  The crosshead type large turbocharged two-cycle combustion engine according to the present invention includes an exhaust gas recirculation passage extending from an exhaust gas flow to a scavenging air flow. Basically, the exhaust gas recirculation flow path extends from a position where the exhaust gas flow branches to a position where the exhaust gas flow joins the scavenging airflow. The total extension defines the total length of the exhaust gas recirculation flow path. While passing through the exhaust gas recirculation path, the exhaust gas undergoes one or more processes, such as a purification process or a temperature control process. One or more of these processes may be performed over the entire length of the exhaust gas recirculation path, or may be configured to be performed in a portion of the exhaust gas recirculation path. Furthermore, a series of processes may be performed in the exhaust gas recirculation path. This provides a great deal of flexibility in the design of the exhaust gas recirculation flow path, greatly increasing its usefulness.

  In certain embodiments, the row extends over a portion of the total length of the exhaust gas recirculation flow path, and the treatment of exhaust gas by one or more devices in the row is performed on a portion of the total length of the exhaust gas recirculation path. . If the row is part of two or more parallel rows, the exhaust gas treatment or control by these parallel rows is likewise performed over part of the total length of the exhaust gas recirculation path. However, it is also possible to perform exhaust gas processing or control in only one of the two columns, or only some of the two or more columns, and stop in the remaining columns. The latter mode of operation gives the option to improve the processing and control in a part of the exhaust gas recirculation path comprising two or more rows, so that the latter mode of operation is in accordance with the overall requirements for exhaust gas recirculation, This is because each device in the queue can be individually controlled.

  According to another embodiment, the rows extend over the entire length of the exhaust gas recirculation flow path. Thus, the treatment and control of exhaust gas by one or more devices in a row is performed over the entire length of the exhaust gas recirculation path. If the row is part of more than one parallel row, processing or controlling the exhaust gas in the set of parallel rows is performed over the entire length of the exhaust gas recirculation path as well. In this embodiment, it is also possible to improve the control of exhaust gas recirculation, which means that more similar devices in a parallel train for exhaust gas treatment or control can be individually controlled as described above. This is because the overall control is improved.

  In certain embodiments where the column extends over a portion of the entire length of the exhaust gas recirculation channel, it is possible to divide the column into two or more parallel columns at a location in the exhaust gas recirculation channel. Two or more parallel rows extend over another (second) portion of the total length of the exhaust gas recirculation flow path. Two or more parallel rows may terminate in the scavenging path or may be integrated at some location in the exhaust gas recirculation flow path.

  As a result, in further embodiments, it is possible to integrate two or more rows at a location in the exhaust gas recirculation flow path.

  Due to the possibility of dividing the column into two or more parallel columns in the exhaust gas recirculation path and the possibility of integrating two or more columns in the exhaust gas recirculation path, various designs are possible for the exhaust gas recirculation path. It is possible to have variations. That is, it is possible to give various variations to a series of processes in parallel rows in the exhaust gas recirculation path portion.

  To facilitate column splitting and integration, the column may be divided into two or more columns by a recirculation receiver, and the two or more columns may be recirculated exhaust gas. receiver). The recirculated exhaust receiver serves as an intermediate receiver for the flow of recirculated exhaust gas and has a shape and size suitable for connection with two or more rows.

  According to the invention, at least part of the exhaust gas recirculation flow path comprises at least two rows in parallel. Each row forms a flow path having at least one device for treating or controlling recirculated exhaust gas. At least one device for treating or controlling recirculated exhaust gas is preferably selected from the group comprising wet scrubbers, dry filters, coolers, condensers, heaters, mist catchers, blowers, compressors, and valves Is done. Devices such as wet scrubbers, dry filters, condensers, and mist catchers are all very suitable for treating exhaust gases, for example, for purifying gases. Devices such as coolers, heaters, blowers, compressors, and valves are suitable for controlling the state of the recirculated exhaust gas.

  In certain embodiments, at least one of the columns includes a valve for activating or deactivating the associated column. The valve may be closed to stop the row and open to activate the row. In this way, the rows can be easily switched on and off in response to the overall requirements for recirculated exhaust gas treatment.

  The crosshead two-cycle combustion engine according to the present invention may further comprise a controller connected to one or more of the devices for processing or controlling the recirculated exhaust gas. The controller can monitor conditions in the equipment that processes or controls the recirculated exhaust gas and can control the conditions in the equipment in response to inputs from the controller's monitoring, thereby improving engine performance. The The controller can be a computer or similar device. Inputs to the controller can be in the form of physical parameters such as temperature, pressure, flow rate, and humidity. From these parameters, the controller can estimate the load on the device and control the device as needed.

  In certain embodiments, the controller is configured to control the devices in the column in response to local conditions in the column. In this embodiment, the controller can optimize the state in one row and reduce the load on the device in that row, which has a positive impact on the life of the device.

  In a further embodiment, the controller is configured to control all devices in the row according to engine operating conditions. In the present embodiment, the controller attempts to optimize the operation state in the exhaust gas recirculation flow path, and thus optimize the operation of the engine.

  In a further aspect, the present invention provides a crosshead type large turbocharger comprising a plurality of cylinders each connected to an exhaust receiver and an exhaust gas recirculation path for reintroducing at least a portion of the exhaust gas into the scavenging path. A method for controlling an exhaust gas recirculation system in a feed type two-cycle combustion engine, wherein at least a part of the exhaust gas recirculation flow path comprises a plurality of parallel rows, each row forming a flow path, Relates to a method comprising selectively opening or closing at least one of the rows to pass recirculated exhaust gas.

  Using the method according to the invention, it is possible to operate the exhaust gas recirculation system in a very flexible manner and at the same time reduce the load on the devices in the system. This is due to the fact that it is possible to selectively open or close at least one of the columns in order to allow the recirculated exhaust gas to pass through a plurality of parallel columns. Of course, depending on the amount of recirculated exhaust gas, it is possible to open all rows, open one or more of the rows, or close access to all of the rows. . However, if all of the parallel rows are closed, the exhaust gas is not recirculated.

  For this reason, in some embodiments, the above method includes monitoring the operating state of the engine as a function of the operating state to determine the requirements for the recirculated exhaust gas. According to this embodiment, it is possible to optimize the operation of the engine by optimizing the amount of recirculated exhaust gas. In practice, this optimization is obtained by selective opening or closing of the rows to allow the recirculated exhaust gas to pass according to the requirements for the recirculated exhaust gas.

  However, the recirculated exhaust gas in the recirculated exhaust gas path may not meet much of the requirements for optimal operation with respect to optimizing engine operation, for example, the temperature or pressure of the recirculated exhaust gas may not be optimal. Absent. Thus, processing or control of the recirculated exhaust gas may be required to obtain optimum characteristics. Accordingly, the method according to the invention includes embodiments in which each one or more of the columns comprises an apparatus for processing or controlling recirculated exhaust gas. Furthermore, embodiments include the use of a controller, eg, a computer to adjust or control the associated row of devices. In this way, it is possible to achieve an engine optimizing operation by obtaining the desired characteristics in the recirculated exhaust gas.

  In a further embodiment of the method, the different combinations of the recirculated exhaust gas passage allow different types of treatment of the recirculated exhaust gas.

  Different combinations may comprise parallel columns, each column performing a process that is different from the process performed by the other columns. However, the different combinations may be a series of similar parallel columns, where one set of parallel columns performs a process that is different from the process performed in another set of parallel columns. This may be, for example, a first set of identical parallel columns, followed by a second set of parallel identical columns, where the first set of columns is a second set of column devices. With devices of different types and functions. These embodiments allow for great freedom in designing an optimized exhaust gas recirculation system.

  Similarly, the present invention includes embodiments that allow different combinations of recirculated exhaust gas passages to allow different recirculated exhaust gas capacities.

  According to the method of the present invention, the apparatus in the row is preferably selected from the group comprising wet scrubbers, filters, coolers, heaters, moisture removers, blowers, compressors, and valves. Devices such as wet scrubbers, dry filters, condensers, and mist catchers are all very suitable for treating exhaust gases, for example, for purifying gases. Devices such as chillers, heaters, blowers, compressors, and valves are suitable for controlling conditions in the recirculated exhaust gas. Therefore, it is possible to obtain optimal treatment and control of the exhaust gas by an appropriate combination of such devices.

  In a further embodiment of the method according to the invention, rows or rows of rows are used to have rows with different capacities and to achieve the desired exhaust gas recirculation capacity. For example, it is possible to have three parallel columns, the first column has a low capacity, the second column has an intermediate capacity, and the third column has a high capacity. By using these three rows in combination, it is possible to obtain any desired capacity in the recirculated exhaust gas system, for example by operating one or more of the rows.

  Further objects, features, advantages and characteristics of the large two-cycle combustion engine and method according to the present invention will become apparent from the detailed description.

The invention will now be described in more detail with reference to exemplary embodiments shown in the drawings.
FIG. 2 is a diagram of an engine according to the present invention. FIG. 3 is an alternative embodiment of an engine according to the present invention. FIG. 4 is an illustration of an embodiment in accordance with the present invention. FIG. 6 is a diagram of a further embodiment according to the present invention.

Detailed Description of the Preferred Embodiment

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Through the detailed description of a crosshead large turbocharged two-cycle diesel engine according to the present invention and a method of operating a crosshead large turbocharged two-cycle diesel engine, the present invention will be described using preferred embodiments. Will be explained.

  The general configuration and operation of a crosshead large turbocharged diesel engine is well known and will not require detailed description here. Details regarding the operation of the exhaust gas system are provided below.

  FIG. 1 shows a first exemplary embodiment of a uniflow large two-cycle diesel engine 1 that is particularly suitable for pressurized exhaust gas recirculation. The engine 1 can be used, for example, as a main engine of an ocean-going ship or as a stationary engine for operating a generator of a power plant. The total power of the engine can be in the range of 5,000 kW to 110,000 kW, for example.

  The engine is provided with a plurality of cylinders 2 arranged in a line. Each cylinder 2 is provided with an exhaust valve 3 in its cylinder cover. The exhaust channel can be opened and closed by an exhaust valve 3. Also shown is the engine crosshead 4 in which the piston rod is connected to the large end of the crankshaft. The exhaust bent portion 5 is connected to the exhaust receiver 6. The exhaust receiver 6 is arranged in parallel with the row of cylinders 2. A part of the exhaust gas is guided from the exhaust receiver 6 to the turbine side of the turbocharger 7 via the exhaust conduit 8 (a plurality of turbochargers may exist). The remaining exhaust gas is taken into the exhaust gas recirculation flow path, described in more detail below, to be reused. The exhaust gas is discharged to the atmosphere on the downstream side of the turbine of the turbocharger 7 via the outlet 9.

  The turbocharger 7 also includes a compressor connected to the outside air intake 10. The compressor supplies pressurized scavenging to the scavenging receiver 11 via the scavenging cooler 12 and the scavenging conduit 13. The scavenging conduit 13 connects the scavenging cooler 12 and the scavenging receiver 11. The cooler 12 is a combination of an intercooler and a mist catcher. The mist catcher removes excess moisture that condenses when the gas is cooled. If the outside air is relatively warm, it can contain a significant amount of moisture in the form of water vapor. When the outside air is cooled in the cooler 12, the water vapor condenses into water, which is collected by a mist catcher. Thus, the system can actually produce fresh water. The scavenging is guided from the supply / scavenging receiver 11 to the scavenging port 14 of each cylinder 2.

  The exhaust receiver 6 is also connected to an exhaust gas recirculation conduit 15 that forms part of the exhaust gas recirculation path 16. The recirculation line 15 is divided into two parallel rows 17a and 17b.

  Each row includes wet scrubbers 18a and 18b, respectively. In each of the wet scrubbers 18a and 18b, the exhaust gas contacts cleaning droplets that are sprayed into the gas from one or more nozzles. The cleaning liquid is usually based on water. The cleaning droplets purify the gas by absorbing particles such as catalyst fine particles, fuel residues, soot particles, and sulfur compounds. In addition to purifying the exhaust gas, the wet cleaning action cools the exhaust gas. The cleaning process may be performed in one or more steps. The cleaning droplets are carried with the cleaned gas, separated from the gas stream at the outlets of the wet scrubbers 18a, 18b, and discarded from the outlet (not shown).

  The wet scrubbers 18a and 18b are followed by coolers 19a and 19b, respectively. The coolers 19a and 19b may be provided with an integral mist catcher. In the coolers 19a and 19b, the exhaust gas is cooled, and moisture contained therein (water generated from the combustion process and moisture derived from evaporation in the scrubbers 18a and 18b) can be condensed in the cooler. The integrated mist catcher (separating means) collects condensed water and small water droplets carried from the scrubbers 18a and 18b. Moisture collected in the mist catchers of the respective coolers 19a and 19b is discarded through an outlet (not shown).

  By removing moisture from the recirculated exhaust gas, the mass flow rate of the recirculated exhaust gas is reduced, thereby reducing the mass flow rate through the cooler 19a, 19b and the device for treating the exhaust gas.

  The blower 20a is disposed downstream of the cooler 19a, and the blower 20b is disposed downstream of the cooler 20b. The blowers 20a and 20b serve to increase the pressure of the exhaust gas in order to obtain a pressure substantially corresponding to the scavenging pressure at the point where the recirculated exhaust gas joins in the scavenging airflow.

  Valves 21a and 21b are mounted at the end of each of the rows 17a and 17b. Valves 21a and 21b can be opened to activate rows 17a and 17b, respectively. Also, the valves 21a and 21b can be closed to stop the rows 17a and 17b, respectively. Of course, the valve 21a can be opened and the valve 21b can be closed, and vice versa. Given that columns 17a and 17b have comparable capacities, these columns are each active when the actual demand for exhaust gas recirculation is moderate. If the demand for recirculated exhaust gas is high, both valves 21a and 21b are opened. The capacity of the column 17a may be different from the capacity of the column 17b. In one embodiment, the capacity of column 17a is twice that of column 17b. According to this embodiment, 33% capacity setting in which only the column 17b functions, 66% capacity setting in which only the column 17a functions, and 100% capacity setting in which both the columns 17a and 17b function are possible. This principle can be extended for an additional number of parallel columns to provide even more capacity settings.

  Scrubbers 18a, 18b, coolers 19a, 19b, blowers 20a, 20b, and valves 21a, 21b all monitor the operation of the controller, eg, rows 17a, 17b, and are responsive to actual conditions in the rows. Connected to a computer that regulates the operation of the cooler, blower, and valves.

  Rows 17a and 17b end at an exhaust gas recirculation line 15a that guides the recirculated exhaust gas to point 22. At some point of the exhaust gas recirculation line 15a, the gas recirculation line 15a is divided into three lines 22a, 22b, and 22c by a valve (not shown). The line 22a supplies the recirculated exhaust gas into the air taken from the outside air intake 10 by the turbocharger 7. The obtained gas mixture is supplied to the intercooler 12. The line 22a also has a branch 22d that provides the option of supplying recirculated exhaust gas directly to the cooler 12 by a valve (not shown).

  Line 22 b bypasses cooler 12 and mixes recirculated exhaust gas with scavenging after cooler 12. This is an option used when the recirculated exhaust gas does not require further cooling but a high pressure (which is obtained by the auxiliary blower 24) is desired, which is typically the engine 1 Used at low and partial loads. Line 22c provides the option of supplying recirculated exhaust gas directly to scavenge pan 11 when no further processing of recirculated exhaust gas is required.

  The scavenging conduit 13 between the scavenging receiver 11 and the cooler 12 is divided into two lines 13a and 13b. The line 13a is equipped with a one-way valve 23, which allows gas from the cooler 12 to enter the scavenging receiver when the gas pressure is sufficient and the auxiliary blower is not activated. become. The line 13b is provided with an auxiliary blower 24, and gas from the cooler 12 is guided through the auxiliary blower 24 when the pressure of the gas is not high enough, that is, when the engine load is low or partial. .

  FIG. 2 shows an alternative embodiment of an engine according to the present invention. The engine 1 is modified to be suitable for low pressure exhaust gas recirculation, i.e. exhaust gas recirculation on the low pressure side of the turbocharger 7. The same reference numerals as those in FIG. 1 denote the same parts as those in FIG. In this figure, the cylinder, piston, crosshead, and exhaust gas curve are shown only as 2 'shown as a rectangle for simplicity.

  The embodiment of FIG. 2 differs from the embodiment of FIG. 1 in that the exhaust gas recirculation path 16 is branched from an exhaust gas outlet 9 exiting from the turbocharger 7. In the exhaust gas recirculation path 16, the exhaust gas is guided to the parallel rows 17a and 17b, and before entering the exhaust gas recirculation line 15 in each row, the cooler 19a including the wet scrubbers 18a and 18b and the integrated mist catcher. 19b, blowers 20a and 20b, and valves 21a and 21b. The processing of the exhaust gas in the recirculation path 16 corresponds to the processing described in FIG.

  The recirculated exhaust gas is guided to the turbocharger 7 via the exhaust gas recirculation line 15. Before entering the turbocharger 7, the recirculated exhaust gas is mixed with the outside air from the outside air intake 10. The scavenging gas is guided from the turbocharger 7 to the cooler 12 via the conduit 10a and to the scavenging receiver 11 via the line 13a or 13b. A one-way valve 23 is attached to the line 13a. When the pressure of the scavenging air from the cooler 12 is sufficiently high, the one-way valve 23 allows the scavenging gas from the cooler 12 to directly enter the air supply receiver 11. The line 13b is provided with an auxiliary blower 24, and when the pressure of the scavenging air from the cooler 12 is not sufficiently high, that is, in a low load state, the pressure of the scavenging air from the cooling machine 12 is increased by the auxiliary blower 24. To do.

  3 and 4 illustrate further embodiments of the present invention. For simplicity, only the most relevant parts of the engine are shown in this drawing. The embodiments illustrated in FIGS. 3 and 4 are suitable for use in both high pressure exhaust gas recirculation systems and low pressure exhaust gas recirculation systems.

  FIG. 3 illustrates the exhaust receiver 20 and the scavenging gas receiver 21. The exhaust gas flows into the exhaust receiver 20 at the inlet 20a and flows out of the exhaust receiver at the outlet 20a. Similarly, outside air flows into the scavenging gas receiver 21 from the inlet 21a, and scavenging flows out of the scavenging gas receiver 21 at the outlet 21a. An exhaust gas recirculation path 22 is formed between the exhaust receiver 20 and the scavenging gas receiver 21. The exhaust gas recirculation path 22 includes three parallel rows 23a, 23b, and 23c. Each row includes wet scrubbers 24a, 24b, 24c, coolers 25a, 25b, 25c, blowers 26a, 26b, 26c, and valves 27a, 27b, 27c. These devices perform the same operation on the exhaust gas as described above for similar devices.

  The columns 23a, 23b, and 23c may each have the same capacity. Thus, for example, if only the row 23a is used, the requirement for recirculated exhaust gas is up to about 33% of the total capacity of all rows combined. If the recycle gas requirement is up to about 66% of the total capacity, two rows (eg 23a and 23b) are used. If the recirculation exhaust requirement is in the range of about 66% to about 100% of the total capacity, three rows 23a, 23b, 23c are used simultaneously. Of course, if the capacity requirement is low, it is possible to change which column is used as a single column. Column 23b or 23c may be used as a single column. If there are requirements for two columns, columns 23a and 23c or columns 23b and 23c may be used together. This provides the system with great flexibility for recirculating exhaust gases.

  As an alternative, the columns 23a, 23b, 23c may have a capacity different from the capacity of the other two columns. For example, column 23a may have 0% to 20% of the total capacity of the system, column 23b may have 0% to 30% of the total capacity of the system, and column 23c. May have 0% to 50% of the total capacity of the system. This alternative embodiment also provides great flexibility in the design and operation of the exhaust gas recirculation system. If the capacity requirement is about 50%, row 23c may be used alone, or rows 23a and 23c may be used simultaneously. Similarly, if the capacity requirement is about 80%, columns 23b and 23c may be used simultaneously.

  FIG. 4 illustrates an alternative embodiment. In FIG. 4, an exhaust receiver 30 and a scavenging gas receiver 31 are shown. The exhaust gas enters the exhaust receiver 30 at the inlet 30a and exits from the exhaust receiver through the outlet 30a. Outside air enters the scavenging gas receiver 31 via the inlet 31a, and the scavenging gas exits from the scavenging gas receiver 31 via the outlet 31b. An exhaust gas recirculation path 32 is formed between the exhaust receiver 30 and the scavenging gas receiver 31. The exhaust gas recirculation path 32 includes a first portion including three parallel rows 33a, 33b, and 33c and a second portion including two parallel rows 33d and 33e.

  In the three parallel rows 33a, 33b, 33c, each row includes a wet scrubber 34a, 34b, 34c. In the second part, each of the two parallel rows 34d and 34e includes coolers 35a and 35b, blowers 36a and 36b, and valves 37a and 37b. The two groups of parallel rows are connected via a cleaning gas receiver 38.

  The three rows 33a, 33b, 33c may have the same capacity or different capacities. Also, the two rows 33d and 33e may have the same capacity for the recycle gas or may have different capacities. Rows 33d and 33e can be individually activated or deactivated by valves 37a and 37b, depending on the actual demand for recirculated exhaust gas. Valves 37c, 37d, and 37e may also be included in rows 33a, 33b, and 33c, respectively, upstream of wet scrubbers 34a, 34b, and 34c. In this embodiment, the wet scrubber can be operated individually, which can improve flow control and water consumption.

  A first part comprising three parallel rows 33a, 33b, 33c comprising scrubbers 34a, 34b, 34c and a subsequent part comprising two parallel rows 33d and 33d comprising coolers 35a, 35b and blowers 36a and 36b. Certain embodiments have, for example, high cleaning requirements (exhaust gas contamination may be relatively high due to, for example, the high sulfur content of the fuel), while cooling and blowing requirements are relatively high. May be appropriate for low cases. The present invention provides an economical and advantageous solution to this situation.

  Alternatively, it is possible to use smaller wet scrubbers 34a, 34b, 34c in rows 33a, 33b, 33c and larger coolers 35a and 35b in rows 33d and 33e.

  Furthermore, the wet scrubbers 34a, 34b, 34c can be integrated into the cleaning gas receiver 38, which in this embodiment serves as a common receiver for three separate cleaning systems.

  As a result, the present invention allows for a wide variety of possible designs and applications of exhaust gas recirculation systems.

  The teachings of the present invention have a number of advantages. Various embodiments or implementations may provide one or more of the following advantages. It should be noted that this is not an exclusive list and there may be other advantages not described herein. One advantage of the teachings of this application is that it provides significant flexibility in the design and operation of exhaust gas recirculation systems.

  Furthermore, because of its flexibility and space savings, the present invention may be utilized in existing engines that do not yet have a recirculated exhaust gas system.

  While the teachings of the present application have been described for purposes of illustration, such details are intended solely for that purpose and have been modified by those skilled in the art without departing from the scope of the teachings of the present application. I hope you understand.

  It should also be noted that there are many alternative ways of implementing the apparatus of the present teachings. For example, multiple rows of exhaust gas recirculation systems can be installed in an existing engine.

  The term “comprising”, when used in the claims, does not exclude other elements or steps. The singular terms in the claims do not exclude the plural. A single processor or other unit may fulfill the functions of several means recited in the claims.

  Thus, a blow-only row and / or a cooling-only row, or for example a part containing one common scrubber, is also anticipated, and a combination possibly with cleaning gas cooling located downstream of the blowing means. Also, embodiments with internal subsequence branching, switching, reconnecting, adding, combining, or jumping, and having locally similar functions are also anticipated and are within the scope of the claims .

Preferred embodiments of the present invention described in the claims of the original application immediately before the divisional application of the present application are as follows.
[Embodiment 1]
A plurality of cylinders (2) each connected to an exhaust receiver (6);
A scavenging path having a scavenging receiver (11), connected to the cylinder (2);
An exhaust gas recirculation flow path (16) for recirculating at least a portion of the exhaust gas into the scavenging path;
A crosshead large turbocharged two-cycle combustion engine (1) comprising:
At least a part of the exhaust gas recirculation flow path (16) has at least two rows (17a, 17b, 23a, 23b, 23c, 33a, 33b, 33c, 33d, 33e) in parallel, each of which The rows form flow paths and at least one device (19a, 19b, 20a, 20b, 24a, 24b, 24c, 25a, 25b, 25c, 26a, 26b, 26c, 34a) for treating the recirculated exhaust gas. , 34b, 34c, 35a, 35b, 36a, 36b), a crosshead large turbocharged two-cycle combustion engine (1).
[Embodiment 2]
The crosshead large turbocharged two-cycle combustion engine (1) according to the first embodiment, wherein the exhaust gas recirculation flow path (16) connects the exhaust gas flow and the scavenging air flow.
[Embodiment 3]
The row (33a, 33b, 33c, 33d, 33e) extends over a part of the entire length of the exhaust gas recirculation flow path (16), or the row (17a, 17b, 23a, 23b, 23c) The crosshead type large turbocharged two-cycle combustion engine (1) according to the first embodiment, which extends over the entire length of the exhaust gas recirculation flow path.
[Embodiment 4]
The crosshead large turbocharged two-cycle combustion engine (1) according to embodiment 1, wherein the row is divided into two or more rows at a certain position in the exhaust gas recirculation flow path.
[Embodiment 5]
The crosshead large turbocharged two-cycle combustion engine according to embodiment 1 or 4, wherein two or more rows are integrated at a position in the exhaust gas recirculation flow path (32).
[Embodiment 6]
The crosshead large turbocharged two-stroke combustion engine according to embodiment 5, wherein two or more rows (33a, 33b, 33c) are integrated by a recirculation exhaust receiver (38).
[Embodiment 7]
Embodiment 1 wherein the apparatus for treating the recirculated exhaust gas is selected from the group comprising wet scrubbers, dry filters, coolers, condensers, heaters, mist catchers, blowers, and compressors. The crosshead type large turbocharged two-cycle combustion engine (1).
[Embodiment 8]
Embodiment 1 wherein at least one of the rows (17a, 17b, 23a, 23b, 23c, 33a, 33b, 33c, 33d, 33e) includes a valve to activate or deactivate the associated row. The described crosshead type large turbocharged two-cycle combustion engine (1).
[Embodiment 9]
The crosshead large turbocharged two-stroke combustion engine (1) according to embodiment 1, further comprising a controller connected to one or more of the devices for processing the recirculated exhaust gas.
[Embodiment 10]
Embodiment 9 wherein the controller is configured to control the devices in a row in response to local conditions in the row (17a, 17b, 23a, 23b, 23c, 33a, 33b, 33c, 33d, 33e). A large turbocharged two-cycle combustion engine (1) as described in 1.
[Embodiment 11]
The controller is configured to control all the devices in a row (17a, 17b, 23a, 23b, 23c, 33a, 33b, 33c, 33d, 33e) according to the operating state of the engine (1). The crosshead type large turbocharged two-cycle combustion engine (1) according to the ninth embodiment.
[Embodiment 12]
A crosshead large turbocharger comprising a plurality of cylinders (2) each connected to an exhaust receiver (6) and an exhaust gas recirculation path (16) for reintroducing at least part of the exhaust gas into the scavenging path A method for controlling an exhaust gas recirculation system in a supercharged two-cycle combustion engine, comprising:
At least a part of the exhaust gas recirculation flow path (16) includes a plurality of parallel rows (17a, 17b, 23a, 23b, 23c, 33a, 33b, 33c, 33d, 33e), and each row has a flow path. Forming,
Selectively opening or closing at least one of the rows (17a, 17b, 23a, 23b, 23c, 33a, 33b, 33c, 33d, 33e) to pass recirculated exhaust gas;
Devices (19a, 19b, 20a, 20b, 24a, 24b, 24c, 25a, 25b) comprising one or more of the rows (17a, 17b, 23a, 23b, 23c, 33a, 33b, 33c, 33d, 33e) 25c, 26a, 26b, 26c, 34a, 34b, 34c, 35a, 35b, 36a, 36b), and processing the recirculated exhaust gas with a device for processing the recirculated exhaust gas;
A method characterized by.
[Embodiment 13]
13. The method of embodiment 12, comprising monitoring the operating condition of the engine (1) in response to the operating condition to determine a requirement for recirculated exhaust gas.
[Embodiment 14]
According to the requirements for recirculated exhaust gas, the rows (17a, 17b, 23a, 23b, 23c, 33a, 33b, 33c, 33d, 33e) are selectively opened or closed in order to allow the recirculated exhaust gas to pass through. Embodiment 14. The method of embodiment 13, further comprising:
[Embodiment 15]
By changing the combination of the rows (17a, 17b, 23a, 23b, 23c, 33a, 33b, 33c, 33d, 33e) through which the recirculated exhaust gas passes, the type of processing of the recirculated exhaust gas Embodiment 13. The method of embodiment 12, comprising changing
[Embodiment 16]
The exhaust gas recirculation path (16) as a whole is changed by changing the combination of the columns (17a, 17b, 23a, 23b, 23c, 33a, 33b, 33c, 33d, 33e) through which the recirculated exhaust gas passes. Embodiment 13. The method of embodiment 12, comprising changing the volume of.
[Embodiment 17]
The devices in the rows (17a, 17b, 23a, 23b, 23c, 33a, 33b, 33c, 33d, 33e) include wet scrubbers, filters, coolers, heaters, moisture removers, blowers, and compressors. Embodiment 13. The method of embodiment 12 selected from a group.
[Embodiment 18]
The rows (17a, 17b, 23a, 23b, 23c, 33a, 33b, 33c, 33d, 33e) have different capacities and combinations of the rows or the rows to achieve the desired exhaust gas recirculation capacity Embodiment 18. The method of embodiment 17, wherein

Claims (1)

A plurality of cylinders (2) each connected to an exhaust receiver (6);
A scavenging path having a scavenging receiver (11), connected to the cylinder (2);
An exhaust gas recirculation flow path (16) for recirculating at least a portion of the exhaust gas into the scavenging path;
A crosshead large turbocharged two-cycle combustion engine (1) comprising:
At least a part of the exhaust gas recirculation flow path (16) has at least two rows (17a, 17b, 23a, 23b, 23c, 33a, 33b, 33c, 33d, 33e) in parallel, each of which The rows form flow paths and at least one device (19a, 19b, 20a, 20b, 24a, 24b, 24c, 25a, 25b, 25c, 26a, 26b, 26c, 34a) for treating the recirculated exhaust gas. , 34b, 34c, 35a, 35b, 36a, 36b), a crosshead large turbocharged two-cycle combustion engine (1).

Images