FI125412B

FI125412B - Foundations for supporting piston engine and generator

Info

Publication number: FI125412B
Application number: FI20145218A
Authority: FI
Inventors: Tero Frondelius
Original assignee: Wärtsilä Finland Oy
Priority date: 2014-03-07
Filing date: 2014-03-07
Publication date: 2015-10-15
Also published as: FI20145218A; WO2015132463A1

Description

Base frame for supporting piston engine and generator Technical field of the invention

The present invention relates to a base frame for supporting a piston engine and a generator coupled to the piston engine in accordance with the preamble of claim 1.

Background of the invention

Large internal combustion engines, such as ship or power plant engines, are typically arranged on a base frame, which rests on a floor of a power plant or an engine room of a ship. In the case of ship engines, resilient mounts can be used between the base frame and the hull of the ship. The engine is often resiliency mounted onto the base frame. If the engine is used for generating electricity at a power plant or for the propulsion or another electric system of a ship, the engine and the generator can be arranged on a common base frame. The base frames are typically made of steel or concrete. Large engines require strong and rigid base frames. Consequently, a lot of material is needed and manufacturing of the base frames is expensive. The conventional base frames are also heavy, which makes them difficult to transport. Some prior art constructions are shown in the following publications:

Patent document US 4174482 A discloses a foundation frame for an internal combustion engine and an electrical generator set. The frame comprises a pair of longitudinal parallel tubes of round cross section and cross-tubes connecting the longitudinal tubes. A pair of plates is secured to the tubes for receiving an engine-generator set. The longitudinal tubes define a reservoir for receiving a liquid lubricant. The lubricant is used for damping vibrations. The material of the frame is apparently steel.

Patent application JP 5248252 shows an internal combustion engine, which is supported by base rails, which are arranged on a concrete base. The material of the base rails is not specified.

Summary of the invention

An object of the present invention is to provide an improved base frame for supporting a piston engine and a generator coupled to the piston engine. The characterizing features of the base frame according to the present invention are given in the characterizing part of claim 1.

The base frame according to the invention comprises a core that is at least partly made of concrete and a shell layer made of a metal or an alloy.

Because of the core made of concrete, the shape of the shell layer can be simple. Less weld seams are thus needed compared to conventional steel structures, and the welds are also easier to make. This helps to reduce the manufacturing costs of the base frame.

Brief description of the drawings

Embodiments of the invention are described below in more detail with reference to the accompanying drawings, in which

Fig. 1 shows schematically a partly cross-sectional view of a piston engine and a generator arranged on a common base frame, and

Fig. 2 shows a cross-sectional end view of a base frame according to an embodiment of the invention.

Description of embodiments of the invention

Figure 1 shows schematically a cross-sectional view of a base frame 1 according to an embodiment of the invention. The base frame 1 is a common base frame for an engine 4 and a device driven by the engine 4. In the embodiment of figure 1, the base frame 1 supports a piston engine 4 and a generator 5. The engine 4 is a large internal combustion engine, such as a power plant or ship engine. The rated power of the engine 4 is at least 500 kW. The generator 5 is coupled to the engine 4 with a flexible coupling 6. The coupling 6 transmits the torque of the engine 4 to the generator 5 but allows movements of the engine 4 and the generator 5 in relation to each other in other directions. Instead of the generator 5, the base frame 1 could be used for supporting a pump that is coupled to the engine 4.

The base frame 1 has a sandwich structure. The base frame 1 comprises a core 2 and a shell layer 3. The shell layer 3 completely encloses the core 2. The shell layer 3 thus forms a casing, inside which the core 2 is arranged. Because of the sandwich structure of the base frame 1, the core 2 together with a relatively thin shell layer 3 forms a rigid structure capable of supporting a large piston engine 4 and a generator 5. The core 2 of the base frame 1 can be a solid block. An advantage of a solid block is that it is easy to manufacture by casting. Alternatively, the core 2 can be provided with one or more cavities. The cavities can be used for making the structure lighter. In addition, the cavities can be used for accommodating functions needed by the engine 4 or auxiliary devices of the engine 4. For instance, the core 1 can be provided with a duct for intake air of the engine 4 or the cavities can be used for accommodating cooling liquid channels. Figure 2 shows an embodiment of the invention, where the core 2 is provided with cavities 8, which are used as intake ducts. In the embodiments of the figures, the core 2 is a one-piece part. Flowever, the core 2 could also be formed of several parts.

The shell layer 3 is made of a metal or an alloy. The shell layer 3 can be made of sheet metal and/or thicker plates. Sheet metal refers here to a sheet-like material that is made of a metal or an alloy and has a thickness of not more than 6 mm. Preferably, the shell layer 3 is made of steel. The shell layer 3 can have a uniform thickness, or the surfaces 3a on which the engine 4 and/or the generator 5 are arranged can be made of a thicker material. The shell layer 3 is made of a plurality of sheets or plates, which are joined together by welding. The core 2 of the base frame 1 is at least partly made of concrete. The term “concrete” refers here to a building material obtained by mixing cement, water and any suitable additional substances, such as sand. The core 2 can be reinforced, for instance, by steel bars that are embedded in the core 2. The core 2 can also be pretensioned to increase the tension stiffness of the base frame 1. Preferably, all the parts forming the core 2 comprise concrete. For instance, the core 2 could consists of one or more blocks comprising concrete. Flowever, the core 2 could also be formed of one or more parts comprising concrete and one or more parts made of some other material or materials, such as steel.

Because of the simple structure of the base frame 1, the base frame 1 is easier and less expensive to manufacture than conventional base frames. Compared to a conventional steel structure used for supporting an engine and a generator, the base frame 1 according to the invention needs less weld seams. The seams are also easier to make and the manufacturing process can be automated to a greater extent. The base frame 1 can be manufactured by first forming the shell layer 3, but leaving at least part of the upper surface of the shell layer 3 open. After forming the shell layer 3, possible reinforcing bars and/or cores needed for forming cavities 8 into the base frame 1 are arranged into the space formed by the shell layer 3. After that, the concrete can be cast-ed to form the core 2 inside the space formed by the shell layer 3. When the concrete is dry, the shell layer 3 can be completed by closing the openings which had been left for the casting of the concrete. An alternative way to manufacture the base frame 1 is to form the core 2 first and then enclose the core 2 inside the shell layer 3.

The properties of the base frame 1 can be improved by suitable selection of the start materials of the core 2. For instance, the core 2 or part of the core 2 can be made of lightweight concrete. With the use of lightweight concrete, the weight of the base frame 1 can be reduced. The term “lightweight concrete” refers here to both lightweight concretes made by using lightweight aggregates and lightweight concretes made by increasing the porosity of the mixture making up the concrete. The latter group of lightweight concretes includes, for instance, autoclaved aerated concrete (AAC). AAC comprises aluminum powder, which reacts in the manufacturing process with calcium hydroxide and water to form hydrogen. The hydrogen gas causes foaming of the mixture and increases the volume of the mixture. Later during the manufacturing process the hydrogen escapes from the concrete and is replaced by air. The result of the process is solid but still soft material, which has a much smaller density than normal concrete. The blocks are placed in an autoclave chamber, where they are held in increased temperature and pressure for 12 hours. During the process, quartz sand reacts with calcium hydroxide and forms calcium silica hydrate, which gives AAC its characteristic properties.

The properties of the core 2 can also be improved by mixing rubber with the other substances used for manufacturing the concrete. The rubber in the concrete improves the damping properties of the base frame 1. According to an embodiment of the invention, crushed car tires are mixed into the core materi- al. In addition to the rubber, tires also contain steel fibers, which function as a reinforcing elements in the concrete.

The base frame 1 can be provided with resilient supports 7 for supporting the base frame 1 on a floor surface of a power plant or against the hull of a ship. The resilient supports 7 can be, for instance, steel springs or support elements, which contain rubber. The resilient supports 7 below the base frame 1 reduce transmission of vibrations from the base frame 1 to the surface supporting the base frame 1. The engine 4 and the generator 5 can be either rigidly mounted to the base frame 1 or resilient supports 9 can be arranged between the base frame 1 and the engine 4 and/or the base frame 1 and the generator 5. Figure 2 shows resilient supports 9 that are provided for mounting an engine 4 onto the base frame 1.

Claims

1. Alarunko (1) mäntämoottorin (4) ja mäntämoottoriin (4) kytketyn generaattorin (5) tukemiseksi, joka alarunko (1) käsittää ytimen (2), joka on ainakin osittain valmistettu betonista, ja kuorikerroksen (3), joka on valmistettu metallista tai metalliseoksesta, tunnettu siitä, että kuorikerros (3) ympäröi ytimen (2) kokonaan.A bottom frame (1) for supporting a piston engine (4) and a generator (5) coupled to the piston engine (4), comprising a core (2) made at least partially of concrete, and a shell layer (3) made of metal. or an alloy, characterized in that the core (2) is completely surrounded by a layer (3) of shells.

2. Patenttivaatimuksen 1 mukainen alarunko (1), tunnettu siitä, että kuorikerros (3) on valmistettu teräksestä.Subframe (1) according to Claim 1, characterized in that the cover layer (3) is made of steel.

3. Patenttivaatimuksen 1 tai 2 mukainen alarunko (1), tunnettu siitä, että ydin (2) käsittää kevytbetonia.Subframe (1) according to claim 1 or 2, characterized in that the core (2) comprises lightweight concrete.

4. Patenttivaatimuksen 3 mukainen alarunko (1), tunnettu siitä, että ydin (2) käsittää höyrykarkaistua kevytbetonia.Subframe (1) according to claim 3, characterized in that the core (2) comprises aerated concrete.

5. Jonkin edeltävistä patenttivaatimuksista mukainen alarunko (1), tunnettu siitä, että ydin (2) käsittää kumia sisältävää betonia.Subframe (1) according to one of the preceding claims, characterized in that the core (2) comprises rubber-containing concrete.

6. Patenttivaatimuksen 5 mukainen alarunko (1), tunnettu siitä, että ydin (2) sisältää murskattuja autonrenkaita.Lower frame (1) according to Claim 5, characterized in that the core (2) comprises crushed car tires.

7. Jonkin edeltävistä patenttivaatimuksista mukainen alarunko (1), tunnettu siitä, että ydin (2) on varustettu kanavalla (8) moottorin (4) imuilmaa varten.Subframe (1) according to one of the preceding claims, characterized in that the core (2) is provided with a channel (8) for the intake air of the motor (4).

8. Jonkin edeltävistä patenttivaatimuksista mukainen alarunko (1), tunnettu siitä, että ydin (2) on yhtä kappaletta oleva osa.Subframe (1) according to one of the preceding claims, characterized in that the core (2) is a single piece.

9. Jonkin patenttivaatimuksista 1 - 7 mukainen alarunko (1), tunnettu siitä, että ydin (2) käsittää useita osia järjestettyinä kuorikerroksen (3) muodostaman tilan sisään.Subframe (1) according to one of Claims 1 to 7, characterized in that the core (2) comprises a plurality of parts arranged inside a space formed by the shell layer (3).

10. Jonkin edeltävistä patenttivaatimuksista mukainen alarunko (1), tunnettu siitä, että alarunko (1) käsittää joukon joustavia tukia (7) alarungon (1) tukemiseksi lattiapintaa vasten.Subframe (1) according to one of the preceding claims, characterized in that the subframe (1) comprises a plurality of flexible supports (7) for supporting the subframe (1) against the floor surface.

11. Patenttivaatimuksen 10 mukainen alarunko (1), tunnettu siitä, että joustavat tuet (7) ovat teräsjousia.Lower frame (1) according to Claim 10, characterized in that the flexible supports (7) are steel springs.

12. Patenttivaatimuksen 10 mukainen alarunko (1), tunnettu siitä, että joustavat tuet (7) ovat kumia sisältäviä tukielementtejä.Subframe (1) according to claim 10, characterized in that the flexible supports (7) are rubber-containing support elements.

13. Jonkin edeltävistä patenttivaatimuksista mukainen alarunko (1), tunnettu siitä, että alarunko (1) käsittää joukon joustavia tukia (9) moottorin (4) ja/tai generaattorin (5) tukemiseksi alarunkoa (1) vasten.Subframe (1) according to one of the preceding claims, characterized in that the subframe (1) comprises a plurality of flexible supports (9) for supporting the motor (4) and / or the generator (5) against the subframe (1).

14. Moottori-generaattorikokonaisuus, joka käsittää jonkin edeltävistä patenttivaatimuksista mukaisen alarungon (1) sekä mäntämoottorin (4) ja generaattorin (5) järjestettyinä alarungon (1) päälle.An engine-generator assembly comprising a subframe (1) according to any one of the preceding claims and a piston engine (4) and a generator (5) arranged on the subframe (1).