JP4995990B1 - Large two-stroke diesel engine, and support plate structure for connecting engine main structure and exhaust gas receiver - Google Patents

Abstract

【Task】
The present invention provides a large two-stroke diesel engine having a plate structure for connecting an engine main structure and an exhaust gas receiver.
[Solution]
The large two-stroke diesel engine includes an engine main structure, an exhaust gas receiver, and a plurality of upright plate structures that support the exhaust gas receiver on the engine main structure below the exhaust gas receiver. The support plate structure is composed of two opposing steel plates each having an upper end and a lower end, a connector for connecting the two steel plates at a predetermined distance at the upper end and the lower end, and two sheets And at least one spacer disposed between the two steel plates between the upper end and the lower end.
[Selection] Figure 3a

Description

  The present invention relates to a large two-stroke diesel engine having an engine main structure, and to a support plate structure for connecting the engine main structure and an exhaust gas receiver.

  Exhaust gas receivers for large two-stroke diesel engines are components that are subjected to high loads that receive high temperature (about 450 ° C.) exhaust gases from individual cylinders under pressures of 4 bar (400 kPa) or less.

  Due to the large dimensions of the exhaust gas receiver (significantly longer than 10 m and having a diameter of 2 m or less) and the high operating temperature, the thermal expansion of the exhaust gas receiver becomes very large, and larger engines are dimensioned by thermal expansion. In order to accept these fluctuations, an exhaust gas receiver divided into two or more housing parts by a bellows is provided. The complete exhaust gas receiver and any components contained in the exhaust gas receiver are fitted with a thin layer of insulation so that the temperature of the outer surface of the exhaust gas receiver is substantially lower than the temperature of the exhaust gas in the exhaust gas receiver. Covered. For safe adjustment, the temperature of the outer surface of the exhaust gas receiver is less than 220 ° C so that exposed engine parts are not at a temperature that will ignite engine fuel or other oil that has been accidentally contacted. It is necessary. In practice, the outer surface of the exhaust gas receiver is sufficiently insulated so that the surface temperature is maintained below 150 ° C.

  The exhaust gas receiver is supported by a rigid main support at the middle or one end in the longitudinal direction of the exhaust gas receiver. A number of flexible supports are distributed along the length of the exhaust gas receiver on both sides of the rigid main support and connect the exhaust gas receiver to the engine housing or engine main structure. Flexible supports are traditionally formed by a single plate, and such supports are necessary to compensate for the thermal expansion and contraction of the exhaust gas receiver as it rises and falls. A substantial movement of the exhaust gas receiver along the longitudinal direction is possible.

German Patent Application Publication No. 4309615 German Patent Application No. 102005016820

  In addition to heat and pressure loads, engine vibrations cause the structure to sway, thereby further increasing the mechanical load on the exhaust gas receiver. One particular problem is that the vibration of the flexible support generates undesirable noise. Attempts have been made to solve this problem by reducing the natural frequency by applying a welded and reinforced rib to the flexible support, but at the position where the rib is welded to the support. Cracks have occurred and the above problem has not been satisfactorily solved.

  In view of the above background, it is an object of the present invention to provide a support plate structure that at least partially solves the above problems.

This object is achieved by increasing the lowest natural frequency of the flexible support without compromising the reliability and durability requirements of the plate structure.
The object of the present invention is realized by providing a flexible support portion as a pair of flexible steel plates arranged to extend along a direction transverse to the longitudinal direction. The main surface extends between the upper end and the lower end so as to face each other at different intervals (S1, S2, S3), and at least one spacer is disposed between the steel plates at a position between the upper end and the lower end. Thus, the steel plate is maintained at a larger distance (S1) at the position of the spacer.

Further objects, features, advantages and properties of the exhaust gas receiver according to the invention will become clear from the present description.
In the following detailed description of the present specification, the present invention will be described in more detail with reference to exemplary embodiments shown in the drawings.

The side view along the longitudinal direction of the large sized 2-stroke engine provided with the plate structure by one Embodiment of this invention. The figure which shows the rear end of the engine shown by FIG. The perspective view which shows the edge part of the exhaust-gas receiver supported by the plate structure by one Embodiment of this invention. FIG. 3b is a side view of the embodiment of FIG. 3a. Fig. 3b is a top view of the embodiment of Fig. 3a. The schematic side view which shows the plate structure at the time of attachment in the low temperature state of an exhaust-gas receiver. The figure which shows not the exact scale but the schematic image of the moment of the plate structure which vibrates while the engine is operating. The figure which shows the test result for comparing a mode that the lowest natural frequency of a plate structure changes.

  1 and 2 show a side view and an end view of an engine main structure 1 of a large two-stroke diesel engine, respectively. The engine is a crosshead type uniflow low-speed two-stroke diesel engine, which may be a propulsion system in a ship or an engine in a power plant. These engines typically have from 3 to 14 cylinders arranged in a row. The engine comprises a bed plate 2 with a main bearing for the crankshaft (only the flywheel 3 attached to the end of the crankshaft is shown). The bed plate 2 may be manufactured as a single part and may be divided into parts of suitable dimensions according to the manufacturing equipment.

  A welded A-shaped frame box 4 is mounted on the bed plate 2. On the exhaust side, the frame box 4 includes a relief valve for each cylinder, while on the camshaft side, the frame box 4 includes a large hinge door for each cylinder. A crosshead guide surface (not shown) is integrated into the frame box 4.

  A cylinder frame 5 is attached to the upper portion of the frame box 4. A retaining bolt (not shown) connects the bed plate 2, the frame box 4, and the cylinder frame 5 to maintain the structure together. The cylinder frame 5 supports individual cylinders 6. Each of the engine cylinders communicates with an inlet of the exhaust gas receiver 16 by an exhaust passage. The cylinder frame 5 forms a scavenging space in cooperation with the cylinder liner 6. A scavenging receiver 9 is fixed to the cylinder frame 5 with bolts. A piston (not shown) is received within each of the cylinder liners 6. A piston rod (not shown) connects the bottom of the piston to the top of the crosshead (not shown). The cylinder liner 6 is supported by the cylinder frame 5.

  The engine is compatible with one or more turbochargers 10 located on the side or rear end of the engine. The cylinder is a uniflow type and includes scavenging holes (not shown) located in the air box. The scavenging air pressurized by the turbocharger 10 is supplied from the scavenging receiver 9 to the air box. Intake into the turbocharger 10 is carried out directly from the engine compartment through a turbocharger intake silencer (not shown). Air flows from the turbocharger 10 to the scavenging holes of the cylinder liner 6 through the air cooler 11, the air supply pipe 12, and the scavenging receiver 9. The engine includes an electrically driven auxiliary scavenging blower 13. The auxiliary blower assists the turbocharger compressor in medium and low load conditions.

  An exhaust valve (not shown) is attached to the center of the cylinder cover 14 at the top of the cylinder. At the end of the expansion stroke, the exhaust valve is opened before the engine piston descends over the scavenging holes, and the combustion gas in the combustion chamber above the piston passes through an exhaust passage that opens into the exhaust gas receiver 16. And the pressure in the combustion chamber is released. The exhaust valve closes again during the upward movement of the piston. The manhole cover allows an operator to approach the exhaust gas receiver 16 during maintenance and inspection.

  As shown in FIG. 1, the exhaust gas receiver 16 is preferably supported by a scavenging receiver 9 of the engine main structure 1. In an alternative embodiment, the exhaust gas receiver 16 is framed via a plurality of plate structures 100 and possibly further via a suitable support flange (not shown), as described below. It may be attached to other main engine structures such as box 4 or cylinder frame 5. Referring again to FIG. 1, the exhaust gas receiver 16 is supported on the scavenging receiver 9 by a rigid main support portion 22. In the embodiment shown, the main support is arranged in the middle in the longitudinal direction of the exhaust gas receiver 16 and fixes the middle of the exhaust gas receiver to the scavenging receiver 9. The main support portion 22 is preferably disposed in the middle of the exhaust gas receiver 16, but does not need to be accurately disposed in the middle and may be slightly shifted. The main support 22 may alternatively be arranged at the end of the exhaust gas receiver 16. As illustrated, the exhaust gas receiver 16 is further mounted on the scavenging receiver 9 via a plurality of flexible supports 100 according to the present invention. The plurality of flexible support portions 100 are distributed on both sides of the rigid support portion 22 along the longitudinal direction of the exhaust gas receiver 16. Each of the flexible supports 100 is against an engine housing or scavenging receiver 9 (or another engine structure (not shown) with a plate structure attached) when the exhaust gas receiver 16 is heated up or down. Formed by a plate structure that follows any contraction or expansion along the length of the exhaust gas receiver 16 due to heat. While the engine is running, hot gas from the combustion chamber of the cylinder is received in the exhaust gas receiver 16. Therefore, the length of the exhaust gas receiver 16 increases due to thermal expansion of the material used for the exhaust gas receiver 16 while the engine is operating. Since the overall length of the exhaust gas receiver 16 of a large two-stroke diesel engine is long (5 to 20 meters), the expansion along the longitudinal direction becomes large (about several centimeters). The total thermal expansion along the lateral direction of the exhaust gas receiver 16, i.e. perpendicular to the plane of FIG. 1, is relatively small because the exhaust gas receiver 16 has a relatively small size. In order to prevent lateral vibration of the exhaust gas receiver 16, the flexible support 100 exhibits little or no elasticity along the lateral direction of the exhaust gas receiver 16.

  Conventionally, a single upstanding plate having a thickness on the order of 10 to 25 mm is used to construct a flexible support or individual plate structure 100, each upright plate conventionally comprising a scavenging receiver 9. And the main surface of the plate is oriented in the lateral direction of the exhaust gas receiver 16, that is, in a direction perpendicular to the longitudinal axis of the elongated exhaust gas receiver 16. It is fixed with bolts. As described in the background section, undesirable resonances of these plate structures have occurred in the engine operating range.

  3a shows the end of an elongated exhaust gas receiver 16 facing the turbocharger 10 shown in more detail in FIG. 1, and the upright support plate structure 100 according to the present invention comprises an exhaust gas receiver 16 and The scavenging receiver 9 is disposed between the mounting bracket 9 '.

  The plate structure 100 according to the present invention comprises two flexible steel plates 110, 115, as better shown in FIG. 3b, the plates 110, 115 comprising the plate structure 100 as an exhaust gas receiver 16 and a scavenging receiver. 9, extending in a direction transverse to the longitudinal axis of the exhaust gas receiver 16, facing each other between the fixtures 120, 125 that are respectively rigidly connected to 9. The thicknesses of the two plates are preferably the same and can be selected widely, and plate thicknesses of the order of 5-10 mm are often selected. In an alternative embodiment, two plates of different thickness are used.

  Plates 110, 115 desirably have similar or identical shapes, with each plate having two opposing major surfaces and side edges. The two steel plates 110 and 115 are arranged so that the main surfaces of each plate face each other. Each plate 110, 115 has an upper end 117, a lower end 118, and a central region 116, as shown in FIG. 3c, and the plate structure 100 connects the central region 116 of the two plates 110, 115 to each other. At least one spacer 130 is provided to maintain a separated state, and the spacer 130 is disposed between the two plates 110 and 115 at a position between the upper end 117 and the lower end 118. The couplings 105 and 102 at the upper and lower ends respectively maintain the two plates 110 and 115 closer to each other than the position of the spacer 130 at the upper and lower ends, and the plate structure 100 is externally attached as shown. The two plates 110 and 115 are spaced apart from each other in the central region 116. The spacer 130 may be arranged in the middle between the two ends 117, 118 or in the middle position between the two connectors 102, 105. In the present invention, as shown in FIG. 3 b, as long as the structure in which the plates 110, 115, which are secured to each other by the spacer 130, protrude outwardly generally results in the desired technical properties of the plate structure 100, the two end portions The position between 117 and 118 need not be exactly in the middle.

  The upper end 117 of the plate structure 100 according to the present invention is attached to a mounting flange 16 'on the exhaust gas receiver 16, and the lower end 118 is attached to another lower fixture 125 on the mounting bracket 9' of the engine main structure. The mounting bracket 9 'is arranged on the scavenging receiver 9 in the illustrated embodiment. In this way, the exhaust gas receiver 16 is mounted on the scavenging receiver 9. In an alternative embodiment, the exhaust gas receiver 16 is connected to other main components such as the frame box 4 or the cylinder frame 5 by means of the described plate structure 100 and possibly a suitable support flange (not shown). Attached to the engine structure.

  As described above, the exhaust gas receiver 16 is mounted on the engine structure such as the scavenging receiver 9 by the plate structure 100. When the engine is in a low temperature state, that is, the engine is not operating, the ambient temperature When the two fixtures 120 and 125 are cooled down, the mounting flange 16 ′ along the longitudinal direction of the exhaust gas receiver 16 is disposed closer to the rigid support portion 22 than the lower mounting bracket 9 ′. That is, as shown in FIG. 3 b, the plate structure 100 is shifted along the horizontal direction so as to be shifted to the right side of FIG. FIG. 4 shows the cold state axis A '. The distance or spacing along the horizontal direction in the cold state between the upper mounting flange 16 'and the lower mounting bracket 9' is preferably an exhaust gas receiver for the engine main structure such as the scavenging receiver 9 in the hot operating state. 16 is selected to correspond to a relative amount of expansion along the longitudinal direction of the mounting flange 16 'and the mounting bracket 9' in the horizontal direction when the exhaust gas receiver 16 is at operating temperature. Are aligned with substantially no spacing and disposed above one.

  As described above, the exhaust gas receiver 16 is mounted on the engine structure such as the scavenging receiver 9 by the plate structure 100 and before the engine is operated, that is, between the mounting flange 16 ′ and the mounting bracket 9 ′. The plate structure 100 is mounted in a state having a distance along the horizontal direction in the low temperature state, and the plate structure 100 supports the exhaust gas receiver 16 and moves the exhaust gas receiver 16 to a predetermined amount while the ship moves. Acts to help fix in position.

  The plates 110 and 115 forming the plate structure 100 are preferably disposed symmetrically with respect to the high temperature state symmetry axis A of the plate structure 100 in the high temperature state, as shown in FIG. Accordingly, the plate structure 100 is elastic or low-temperature so that the plate structure 100 has a slightly distorted configuration or a curved configuration in the process of mounting the plate structure 100 to the shifted mounting flange 9 ′ and the mounting bracket 16 ′. It is plastically deformed or curved. After mechanically aligning the plate structure 100 with the misaligned flange 9 'and bracket 16', the plate structure 100 is coupled onto the flange 16 'and bracket 9', respectively, by a fixture. The plate structure 100 has a distorted configuration as schematically shown in FIG. When the exhaust gas receiver 16 rises in temperature and expands until the flange 16 'and the bracket 9' are not displaced in the horizontal direction, the bending force applied at the time of installation is reduced to the minimum value. The main force on the plate structure 100 includes a force due to a load along the vertical direction due to the weight of the exhaust gas receiver 16 and a force due to vibration of the engine.

  With respect to connection with the plate structure 100, the bolt 106 is tightened to prevent any free rotational movement of the plate ends 117, 118 relative to the fixtures 120, 125. The connectors 102 and 105 formed as metal bars are arranged between the plates 110 and 115 at the upper and lower ends 117 and 118, and the same bolt 106 is connected to the plates 110 and 115 via the connectors 102 and 105. Are connected to each other, and the plate structure 100 is connected to the flange 16 ′ and the bracket 9 ′ via the fixtures 120 and 125, respectively.

  Further, along the direction crossing the plate structure 100, in the vicinity of the middle (region 116) between the upper end and the lower end 117, 118, a row of spacers 130 including a bolt having a bolt head 132 and a nut 133 is provided on the plate. 110 and 115 are fixed with respect to each other and are arranged to ensure that the plates 110 and 115 do not move in or toward each other in the spacer 130. The spacer 130 in the region 116 causes the plates 110, 115 to be larger than the mutual spacing S2, S3 between the plates 110 and 115 at the upper and lower ends 117, 118, respectively, as also shown in the enlarged view in FIG. 3b. Maintain a mutual spacing S1, where S2 may be the same as S3. In this way, the plate structure 100 has an outwardly raised geometric configuration as shown in FIG. 3b, and the plate structure 100 is formed of a truss structure as shown in FIG. As a strut, it vibrates along a transverse direction (indicated by the double-headed arrow D in FIG. 3 b), and this vibration is along the longitudinal direction of the exhaust gas receiver 16. The spacer 130 is a cylindrical metal tube that extends through holes formed in the plates 110 and 115 and has a bolt with a head for maintaining or fixing the space S1 in cooperation with the nut 133. is there. In this way, a completely mechanical connection is formed that does not require welding.

  FIG. 5 (not shown to scale) shows an instantaneous image or “snapshot” of the vibrating plate structure 100 as the engine operates. The instantaneous image means a diagram during the movement of the vibrating plate structure 100, that is, during the moment of vibration. Accordingly, in the figure, the plate structure 100 is shown unclear, and the two individual plates 110, 115 of the vibrating plate structure 100 are difficult to distinguish individually. In the figure, the plate structure 100 is in one of the largest possible positions. The magnitude A of vibration of the plate structure 100 depends on, ie depends on, the high rigidity of the plate structure 100 in the middle between the upper and lower ends 110, 115, and the rigidity of the plate structure 100 depends on the selected plate. And the ratio of the spacing S1 to the spacings S2 and S3, respectively. The magnitude A is shown as the distance from the rest position to the maximum position in FIG.

  FIG. 6 shows, for comparison, the lowest order of the plate structure 100 by using a spacer 130 that provides the desired relative spacing S1 between the steel plates 110, 115 in the middle between the ends 117, 118. It shows how the natural frequency changes. The frequency values are compared for pairs of plates having different thicknesses, and the lowest order natural frequency generally increases with increasing spacing S1. By using a thicker steel plate, the lowest natural frequency is also increased. For comparison, the vibration of a conventional 16 mm single plate is also shown in the figure (indicated by “Diamond”). Since there is no gap in such a single plate, the frequency values are shown on a line parallel to the abscissa in the figure. As can be seen from the figure, using a plate having a thickness that is half the 16 mm thickness of a conventional plate also provides advantages, and therefore, compared to a conventional single plate structure, It is possible to save material while the rigidity of the plate structure 100 is increased.

  In the plate structure 100, after two flat plates 110 and 115 are mechanically arranged together, the plates 117 and 118 are connected to each other using the connectors 102 and 105 at their ends 117 and 118, and stress is applied. The plate structure 100 is attached to the exhaust gas receiver 16 and the scavenging receiver 9. Alternatively, the two plates 110, 115 may be rolled into an unbiased natural shape, as shown in FIG. 3b, after being connected together by bolts 106 and spacers 130, It may be processed.

Although the invention has been described in detail for purposes of illustration, such description is merely illustrative and modifications may be implemented by those skilled in the art without departing from the scope of the invention.
The present invention also relates to a support plate structure 100 for connecting between the engine main structure 1 and the exhaust gas receiver 16.
Two opposing steel plates 110, 115, each having a first end 117 and a second end 118;
At least one spacer 130 for maintaining the two steel plates 110, 115 in a spaced relationship, the spacer being disposed between the steel plates 110, 115 at a position between the first end 117 and the second end 118; 130,
A connector 102, 105 disposed at the first end 117 and the second end 118;
The couplers 102 and 105 maintain the two steel plates 110 and 115 at the first end 117 and the second end 118 so as to be separated from each other by a distance S2 and S3. In position, the two steel plates 110, 115 are kept apart by a larger distance S1. The support plate structure 100 includes any of the features recited in the claims.

The invention further relates to a marine vessel having a large two-stroke diesel engine with a support plate structure 100 with the features as claimed.
In the claims, the term “comprising” does not exclude other elements or steps. In the claims, the use of the singular does not exclude the presence of a plurality of terms. A single processor or other unit may perform the functions of the specific means recited in the claims.

Claims (10)

An engine main structure (1);
An elongate exhaust gas receiver (16) having one or more engine exhaust gas inlets and one or more engine exhaust gas outlets;
A main support (22) disposed below the exhaust gas receiver (16) and supporting the exhaust gas receiver (16) on the engine main structure (1) and a plurality of upright plate structures (100 A large two-stroke diesel engine comprising:
The upright plate structure (100) is distributed along the longitudinal direction of the exhaust gas receiver (16),
Each of the upstanding plate structures (100) has an upper end (117) attached to the exhaust gas receiver (16) and a lower end (118) attached to the engine main structure (1);
At least one of the plate structures (100) is
A pair of flexible steel plates (110, 115) fixed together at the upper end (117) and the lower end (118), the steel plates (110, 115) being connected to the exhaust gas receiver (16) The steel plates (110, 115) are arranged so as to extend along a direction transverse to the longitudinal direction of the steel plates, and the main surfaces of the steel plates (110, 115) extend so as to face each other. The steel plates (110, 115) larger than the spacing at the upper end (117) and the lower end (118);
At least one spacer (130) disposed between the steel plates (110, 115) at a position between the upper end (117) and the lower end (118), wherein the spacer (130) A large two-stroke diesel engine comprising the spacer (130) configured to fix a spacing (S1) between the steel plates (110, 115).   The at least one spacer (130) is arranged to provide a maximum spacing (S1) between the steel plates (110, 115) in the middle between the upper end (117) and the lower end (118). The large two-stroke diesel engine according to claim 1 to be performed.   The plate structure (100) is flexible along the longitudinal direction of the exhaust gas receiver (16) and is adapted to the thermal expansion of the exhaust gas receiver (16) relative to the engine main structure (1). The large two-stroke diesel engine according to claim 1 or 2.   Attachments (120, 125) for attaching the plate structure (100) to the exhaust gas receiver (16) at the upper end (117) and to the engine main structure (1) at the lower end (118). The large-sized two-stroke diesel engine according to any one of claims 1 to 3, further comprising:   5. The steel plate (110, 115) of the at least one plate structure (100) is biased away from each other by the at least one spacer (130). Large two-stroke diesel engine as described.   The large two-stroke diesel engine according to any one of claims 1 to 5, wherein the at least one spacer (130) mechanically connects between the steel plates (110, 115).   The at least one spacer (130) defines the distance (S1) between the steel plates (110, 115) at the position of the spacer (130) according to a length of the spacer (130). A large two-stroke diesel engine according to any one of claims 1 to 6.   The at least one spacer (130) sets a mechanically fixed interval (S1) without welding between the steel plates (110, 115) at the position of the spacer (130). A large two-stroke diesel engine according to any one of claims 7 to 7.   The large two-stroke diesel engine according to any one of claims 1 to 8, wherein the plate structure (100) is supported by a scavenging receiver (9) of the engine main structure (1).   The large two-stroke diesel engine according to any one of claims 1 to 9, wherein the plurality of spacers (130) are arranged in a line.