EP4147964A1 - Method for converting a dry cargo vehicle with a diesel engine as drive motor to operation with methanol - Google Patents

Abstract

Method for converting a dry freighter with a diesel engine as the propulsion engine to operate with methanol, in which a methanol unit comprising at least one methanol tank for supplying the propulsion engine with methanol from the methanol tank is installed in a rear area of the cargo hold in front of the engine bulkhead.

Description

The invention relates to a method for converting a dry freighter with a diesel engine as the drive motor to operate with methanol.

In inland navigation, passenger ships are used for passenger transport and tankers and dry freighters with open cargo holds that can be covered by hatch covers are used for goods transport. These ships are usually equipped with diesel engines as propulsion engines. Although transport by water is significantly more climate-friendly than by truck, since transporting goods by inland waterway transports far fewer grams of greenhouse gases per tonne-kilometre than transport by truck. Nevertheless, a further reduction in emissions for inland waterways would also be desirable.

Proceeding from this, the object of the invention is to provide an inland waterway ship with reduced emissions.

The object is achieved by a method for converting a dry freighter with a diesel engine according to claim 1. Advantageous embodiments of the invention are specified in the dependent claims and in the following description.

In the method according to the invention for converting a dry freighter with a diesel engine as the propulsion engine to operate with methanol as the primary fuel, a methanol unit comprising at least one methanol tank for supplying the propulsion engine with methanol from the methanol tank is installed in the rear area of the hold in front of the engine bulkhead.

The invention is based on the idea that dry freighters with a diesel engine can be converted to operate with methanol in a particularly simple and cost-effective manner. The rear area of the cargo hold in front of the engine room is particularly suitable for the arrangement of a methanol unit with one or more methanol tanks, because the path to the propulsion engine is very short from this position. In addition, the cargo hold offers enough space for accommodating the methanol unit and its capacity for transporting goods is only slightly reduced by this accommodation. The engine room can remain essentially unchanged for the conversion to operation with methanol. In particular, the diesel tank can remain unchanged and, if necessary, be used to supply the drive motor with diesel as an ignition medium, as a reserve fuel and/or to operate an auxiliary diesel (eg for generating electricity). In addition, it is advantageous that dry freighters are relatively similar in structure, so that standardized methods and procedures can be used to convert to operation with methanol with the least possible effort, modularly and with as few structural interventions as possible. It is possible to carry out a retrofit without longer and expensive stays in the shipyard. Even older ships can therefore continue to operate in accordance with current exhaust gas regulations. The process thus enables the environmentally friendly conversion of diesel-powered dry freighters to run on methanol as the sole fuel or on a dual-fuel combustion system with diesel and methanol, so that these machines meet the highest environmental standards (zero emissions) and can therefore make an important contribution to climate protection. On the basis of green methanol, the goal of CO2 neutrality can be achieved and harmful emissions such as NOx and SOx can be significantly reduced. The latter also applies to operation with gray methanol.

Green methanol is produced by generating hydrogen using renewable energies and converting it to methanol in a synthesis with CO2. The CO2 is then released again during combustion. Therefore, a ship can in principle be operated CO2-neutral with green methanol. Gray methanol is based on fossil fuels. Operating a ship with gray methanol has at least the advantage that NOx, SOx and particle emissions are largely avoided. Advantages compared to operation with hydrogen or LNG are in particular the simpler and safer storage and handling of methanol.

According to one embodiment of the method, the drive motor is a diesel engine that can be operated with methanol. This is preferably the diesel engine that was already installed in the dry freighter before the conversion of the dry freighter to run on methanol. In this embodiment, the diesel engine is optionally optimized for operation with methanol by changing settings or other simple measures. According to another embodiment, the drive motor is a diesel engine that is converted to a diesel engine that can be operated with methanol. This is preferably the diesel engine that was already installed in the dry freighter before the conversion of the dry freighter to run on methanol, or a diesel engine from another dry freighter that is of the same or a similar type. This can also be any diesel engine that has been converted to run on methanol. According to another embodiment, the diesel engine installed in the dry freighter before the conversion is replaced by an internal combustion engine that can be operated with methanol. This can preferably be an internal combustion engine specially constructed or designed for operation with methanol.

According to another embodiment, the propulsion engine is a diesel engine provided with a cylinder head with injectors for methanol in addition to injectors for diesel or instead of injectors for diesel. If the diesel engine equipped with injection nozzles for methanol in addition to injection nozzles for diesel, it can also be operated in mixed operation with methanol and diesel. The mixing ratios of methanol and diesel are fundamentally arbitrary. Diesel is preferably added to the drive engine for ignition, it being possible for the proportion of diesel added to be small. A maximum of 10% by weight of diesel, more preferably 3 to 5% by weight of diesel, is preferably added if the diesel engine is operated in mixed operation. Alternatively, the drive motor is provided with the injection nozzles for methanol instead of the injection nozzles for diesel, in order to operate the diesel engine exclusively with methanol. The diesel engine can in particular be the diesel engine installed in the dry freighter before the conversion of the dry freighter to operate with methanol or a diesel engine of the same or similar design from another dry freighter.

According to one embodiment of the method, the methanol unit comprises a methanol system with one or more of the following components: components for delivering methanol from the methanol tank to the drive engine (e.g. a delivery pump), measuring devices for methanol consumption, measuring devices for determining the indicated engine power of the drive engine. According to a further embodiment, the methanol system is connected to the drive engine via at least one fuel line. According to another embodiment, the fuel line is connected to injectors of a diesel engine.

According to a further embodiment, the methanol unit has an inerting system with at least one nitrogen cylinder, which is connected to the methanol tank and/or a hollow jacket space of at least one fuel line via at least one gas line. Using the inerting system, cavities can be filled with inert gas to prevent the accumulation of explosive gas mixtures.

According to a further embodiment, the methanol unit comprises a diesel system for supplying diesel to the diesel engine and the diesel system is connected to a diesel tank in the stern and to the diesel engine. The supply of diesel to the diesel engine in addition to the methanol is controlled via the diesel system. For this purpose, the diesel system is connected via at least one fuel line to the diesel tank that was already present in the stern before the conversion and to the diesel injection nozzles of the diesel engine. According to a further embodiment, the diesel system includes one or more of the following components: components for the promotion of diesel from the diesel tank to the diesel engine (eg a feed pump), measuring devices for the Methanol consumption, measuring devices for determining the indicated engine power of the diesel engine.

According to a further embodiment, the at least one methanol tank is installed in the rear area of the hold in the transverse direction to the axis of the ship. This arrangement means that little loading space is lost for accommodating freight.

According to a further embodiment, exactly two methanol tanks, preferably two methanol tanks arranged next to one another in the transverse direction of the ship, are installed in the rear region of the hold. A methanol tank can be used as a reserve tank. Furthermore, the two methanol tanks can be used to trim the ship.

According to a further embodiment, the methanol system and/or the inerting system and/or the diesel system is arranged between two methanol tanks arranged next to one another. This is beneficial for symmetrical weight distribution and for connecting the various systems to the methanol tanks and fuel lines.

According to a further embodiment, the methanol unit is inserted completely into the hold as a structural unit, preferably by means of a crane. The methanol unit comprises at least the at least one methanol tank. Optionally, the methanol unit also includes the methanol system and/or the inerting system and/or the diesel system. By installing the methanol unit as a structural unit in the hold, the conversion can be greatly simplified and carried out in a short time. The complete methanol unit can be manufactured separately in a production facility, transported to the ship and used in the hold. Due to the structurally largely identical design of the dry freighters, a large number of different ships can be equipped with the same type of methanol unit. It is also possible to expand the methanol unit as a structural unit from the dry freighter. As an alternative to running the methanol unit as a structural unit, the components of the methanol unit are built into the dry freighter separately and/or pre-assembled in smaller assemblies.

According to another embodiment, the methanol unit is 8 m wide (transversely across the ship), 4 m high and 1.5 m long (longitudinally across the ship) and/or the at least one tank has a capacity of 36 m ³ . The dimensions are matched to the largely identical dimensions of the hold of dry freighters. The tank volume is tailored to the loading volume of the common tank vehicles with which the dry freighters can be refueled.

According to a further embodiment, an additional transverse bulkhead is installed in the hold in front of the methanol unit. This shields the hold from the methanol tanks and increases safety.

To further increase safety, the rear area of the cargo hold containing the methanol unit is covered by a cover extending from the machine front bulkhead to the additional transverse bulkhead. According to a further embodiment, the rear area of the cargo space between the machine front bulkhead and transverse bulkhead is equipped with forced ventilation, which ensures a certain air exchange rate in the rear area of the cargo space.

According to another embodiment, the cover has an openable hatch through which the rear part of the hold is accessible to carry out inspections, maintenance or repairs.

In a method for operating a dry freighter converted according to the invention, the diesel engine is operated exclusively with methanol or simultaneously with methanol from the methanol tank and diesel from the diesel tank.

Preferably, no diesel at all or diesel in small proportions of at most 10% by weight, preferably 3 to 5% by weight, is added as the ignition medium for operating the diesel engine. In principle, however, it is also possible to use diesel and methanol in any mixing ratio, since the diesel engine can continue to be operated with diesel fuel after the conversion. The diesel tank can therefore also be used as a reserve tank for operating the dry freighter, for example.

According to another embodiment, green or gray methanol is used to operate the diesel engine.

• Fig. 1a-d ein Trockenfrachter mit Dieselmotor in Seitenansicht (Fig. 1a), Draufsicht (Fig. 1b), einem horizontalen Längsschnitt (Fig. 1c) und einem horizontalen Längsschnitt durch den Maschinenraum (Fig. 1d);
• Fig. 2a-c der hintere Bereich des Laderaums des Trockenfrachters mit eingebauter Methanoleinheit in einem vertikalen Längsschnitt, einem vertikalen Querschnitt und einem horizontalen Längsschnitt, jeweils in einer vergrößerten Teilansicht.

The invention is not explained in more detail below with reference to the attached drawings of an embodiment. In the drawings show:

• Fig. 1a-d a dry freighter with diesel engine in side view ( Fig. 1a ), Top view ( Fig. 1b ), a horizontal longitudinal section ( 1c ) and a horizontal longitudinal section through the engine room ( Fig. 1d );
• Fig. 2a-c the rear area of the hold of the dry freighter with installed methanol unit in a vertical longitudinal section, a vertical cross section and a horizontal longitudinal section, each in an enlarged partial view.

According to 1 A dry freighter 1 with a diesel engine for inland navigation comprises a slim hull 2 with a flat ship bottom 3. The dry freighter 1 has a short fore ship 4, a somewhat longer stern ship 5 and an elongated central ship 6 with a hold 7 open at the top. In the area of the hold 7, the side walls 8, 9 of the ship are designed as ballast tanks 10, 11 for ballast water.

The stern 5 comprises a machine room 12, a shaft system 13, a rudder system 14, a deckhouse 15 with a funnel 16 and a bridge 17 that can be raised and lowered.

The main engine designed as a diesel engine 18, auxiliary diesel engines 19, 20 for generating electricity, a heating system 21 and a hydraulic system 22 for the steering system 14 are arranged in the engine room 12. The shaft system 13 is connected to the main engine 18 .

Below the engine room 12 there is another ballast tank 23 in the bottom of the ship 3 and trim tanks 24, 25 are located on both sides of the engine room.

By filling or emptying the ballast and trim tanks 10, 11, 23, 24, 25, the height of the ship can be adjusted and the position of the dry freighter 1 in the water can be changed, for example to enable bridge passages or to compensate for an uneven distribution of the ship's cargo. Bridge 17 can also be lowered for bridge passages.

In the conversion according to the invention, the entire engine is replaced with an engine that can be operated exclusively with methanol or with an engine that can be operated with methanol and diesel and/or another fuel, or the cylinder head 26 of the diesel engine 18 is provided with injection nozzles for methanol in addition to the injection nozzles for diesel. For this purpose, either the originally existing cylinder head 26 has been replaced by a revised or a new cylinder head with injection nozzles for methanol and diesel, or the original cylinder head has also been provided with injection nozzles for methanol.

The machine room 12 is closed at the front by a machine front bulkhead 27 running in the transverse direction.

According to 2 a methanol unit 28 is installed in the loading space 7 directly in front of the engine bulkhead 27. The methanol unit 28 is a structural unit which is essentially box-shaped, a width (transverse direction of the ship) of 8 m, has a height of 4 m and a length (in the longitudinal direction of the ship) of 1.5 m. The width and height dimensions of the methanol unit 28 are adapted to the dimensions of the loading space 7 .

The methanol unit 28 comprises two methanol tanks 29, 30 which are arranged symmetrically with respect to the longitudinal axis of the ship 1. The methanol tanks 29, 30 can have the same filling volume, which is, for example, 18 m ³ each, ie a total of 36 m 3 .

Between the two methanol tanks 28, 30, the methanol unit 28 has a pocket 31 in which a methanol system 32, an inerting system 33 and, if necessary, a diesel system 34 are arranged. The methanol system 32 includes components for supplying the diesel engine with methanol (e.g. feed pumps), measuring devices for the methanol consumption and measuring devices for determining the indicated engine output.

The inerting system 33 includes gas cylinders 35, valves and (inert) gas lines to the methanol tanks 29, 30 and to hollow jacket spaces around fuel lines to the diesel engine. Nitrogen or another inert gas can be pumped into the methanol tanks or the jacket seams and the fuel lines by means of the inerting system 33 in order to prevent an explosion due to the accumulation of small amounts of gas.

The diesel system 34 includes components for supplying the diesel engine 18 with diesel (e.g. feed pumps), measuring devices for these consumption measurements and measuring devices for determining the indicated engine power. The diesel system 34 can be omitted if the diesel engine 18 can only be operated with methanol or is replaced by an internal combustion engine which can only be operated with methanol.

The methanol tanks 29, 30 can be made of steel and/or plastic.

The methanol unit 28 can be designed in such a way that the methanol tanks 29, 30 form the supporting structure for the systems 32, 33, 34, in particular if the methanol tanks 29, 30 are made of steel. However, it is also possible to use a frame, e.g.

The methanol unit 28 is inserted into the hold 7 with the aid of a crane (e.g. a mobile crane) and connected to the hull 2 by welding, bolting or other fastening methods.

The methanol unit 28 can be installed in the hold 7 without the ship having to be taken to a shipyard for this purpose.

After the methanol unit 28 has been installed in the loading space 7, it is connected to the injection nozzles for methanol and for diesel of the diesel engine 18 via fuel lines. Furthermore, the methanol unit 28 is connected to the diesel engine 18 and/or the bridge 17 via data cables in order to control the methanol and diesel systems 32, 34 depending on the desired engine performance.

An additional transverse bulkhead 36 is welded into the hold 7 directly in front of the methanol unit 28 . The area of the loading space 7 between the machine front bulkhead 27 and the additional transverse bulkhead 36 is covered by a screwed-in cover 37 . The space between the machine front bulkhead 27, additional transverse bulkhead 36 and cover 37 is ventilated.

The pocket 31 for inspection, maintenance and repair of the methanol system 32, inerting system 33 and diesel system 34 can be entered via a hatch 38 in the cover 37 that can be opened. A ladder 39 is built into the pocket 31 for this purpose.

Hatch cover 40 for covering the cargo hold 7 can be moved over the cover 37 .

The two methanol tanks 29, 30 have tank nozzles which are led out through the two side walls of the ship's hull 2 to the outside.

Only an extremely small part of the loading space 7 is lost for the installation of the methanol unit 28 .

The methanol unit 28 can also be easily removed from the ship's hull.

Claims (19)

Method for converting a dry freighter with a diesel engine as the propulsion engine to operate with methanol, in which a methanol unit comprising at least one methanol tank for supplying the propulsion engine with methanol from the methanol tank is installed in a rear area of the cargo hold in front of the engine bulkhead. Method according to Claim 1, in which the drive motor is a diesel engine which can be operated with methanol or is converted to a diesel engine which can be operated with methanol or is replaced by an internal combustion engine which can be operated with methanol. Method according to Claim 1 or 2, in which the driving engine is a diesel engine provided with a cylinder head with injectors for methanol in addition to injectors for diesel or instead of injectors for diesel. Method according to one of Claims 1 to 3, in which the methanol unit is connected to the drive engine via at least one fuel line. Method according to one of Claims 1 to 4, in which the methanol unit comprises a methanol system with one or more of the following components: component for conveying methanol from the methanol tank to the drive engine, measuring devices for methanol consumption, measuring devices for determining the indicated engine power of the drive engine. Method according to one of Claims 1 to 5, in which the methanol unit has an inerting system with at least one nitrogen bottle which is connected via at least one gas line to the methanol tank and/or a hollow jacket space of at least one fuel line. A method according to any one of claims 1 to 6, wherein the methanol unit comprises a diesel system for supplying diesel to the diesel engine. Method according to Claim 7, in which the diesel system is connected to a diesel tank in the stern and to the diesel engine via at least one fuel line. Method according to one of Claims 1 to 8, in which the at least one methanol tank is installed in the rear region of the hold in the transverse direction to the axis of the ship. Method according to one of Claims 1 to 9, in which two methanol tanks, preferably two methanol tanks arranged next to one another in the transverse direction of the ship, are installed in the rear region of the hold. Method according to one of Claims 1 to 10, in which the methanol system and/or the inerting system and/or the diesel system is arranged between two methanol tanks arranged next to one another. Method according to one of Claims 1 to 11, in which the methanol unit is inserted into the hold as a structural unit. A method according to any one of claims 1 to 12, wherein the methanol unit has dimensions of about 8 x 4 x 1.5 m and/or wherein the at least one tank has a capacity of 36 m ³ . Method according to one of Claims 1 to 13, in which an additional transverse bulkhead is installed in the hold in front of the methanol unit. Method according to Claim 14, in which the rear region of the hold containing the methanol unit is covered by a cover extending from the engine front bulkhead to the additional transverse bulkhead. A method according to any one of claims 1 to 15, wherein the lid has an openable hatch. Method for operating a dry freighter converted according to one of Claims 1 to 16, in which the drive motor is operated exclusively with methanol from the methanol tank or simultaneously with methanol from the methanol tank and diesel from the diesel tank. Method according to Claim 17, in which the proportion of diesel in the total fuel injected into the drive engine is at most 10% by weight, preferably 3 to 5% by weight. A method according to claim 17 or 18, in which green or gray methanol is used to operate the drive motor.

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