Method for converting a dry cargo ship with a diesel engine as its propulsion engine to operation with methanol

Abstract

Method for converting a dry cargo ship with a diesel engine as the propulsion engine to operation 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 front bulkhead.

Description

[0001] The invention relates to a method for converting a dry cargo ship with a diesel engine as a drive engine to operation with methanol.

[0002] Inland navigation uses passenger ships for passenger transport and tankers and dry cargo ships with open cargo holds and those covered by hatches for freight transport. These vessels are generally equipped with diesel engines. While transport by water is significantly more climate-friendly than by truck, as freight transport by inland waterway emits considerably fewer grams of greenhouse gases per ton-kilometer than transport by truck, further reductions in emissions would still be desirable for inland vessels as well.

[0003] GREEN MARITIME METHANOL: Green maritime methanol: WP 5 - system design for short sea shipping. The Hague, 2021. 77 pp. Section 5.5 of the company publication describes a dry cargo ship in which a tank for heavy fuel oil in the center is converted into a tank for methanol. CN 1 13 047 994 A describes a tanker in which a liquid tank forward of the engine room is converted into a methanol tank.

[0004] Based on this, the invention aims to provide an inland waterway vessel with reduced emissions.

[0005] The problem is solved by a method for converting a dry cargo ship with a diesel engine according to claim 1. Advantageous embodiments of the invention are specified in the dependent claims and in the following description.

[0006] In the inventive method for converting a dry freighter with a diesel engine as the drive engine to operation with methanol as the primary fuel, a methanol unit comprising at least one methanol tank for supplying the drive engine with methanol from the methanol tank is installed in the rear area of ​​the cargo hold in front of the engine front bulkhead.

[0007] The invention is based on the idea that dry cargo ships with diesel engines can be converted to methanol operation particularly easily and cost-effectively. The rear section of the cargo hold, forward of the engine room, is especially suitable for accommodating a methanol unit with one or more methanol tanks because the distance to the propulsion engine is very short from this position. Furthermore, the cargo hold offers sufficient space for housing the methanol unit, and its cargo capacity is only minimally reduced by this installation. The engine room can remain essentially unchanged for the conversion to methanol operation. In particular, the diesel tank can be retained and, if necessary, used to supply the propulsion engine with diesel as an ignition medium, as reserve fuel, and / or for operating an auxiliary diesel engine (e.g., for power generation).Furthermore, it is advantageous that dry cargo ships are relatively similar in design, allowing for the use of standardized methods and procedures to convert them to methanol operation with minimal effort, modularity, and as few shipbuilding modifications as possible. Retrofitting can be carried out without lengthy and expensive shipyard stays. Even older ships can thus remain in operation in compliance with current emissions regulations. This process enables the environmentally friendly conversion of diesel-powered dry cargo ships to operation with methanol as the sole fuel or to a dual-fuel combustion system using diesel and methanol, allowing these vessels to meet the highest environmental standards (zero emissions) and thus make a significant contribution to climate protection. Based on green methanol, the goal of CO2 neutrality can be achieved, and harmful emissions such as NOₓ can be eliminated. x and SOx significantly reduced. The latter also applies to operation with grey methanol.

[0008] Green methanol is produced by generating hydrogen using renewable energy and then synthesizing it with CO2 to create methanol. The CO2 is then released again during combustion. Therefore, a ship can, in principle, operate CO2-neutrally with green methanol. Gray methanol is based on fossil fuels. Operating a ship with gray methanol has at least the advantage that NOₓ emissions are lower. x -, SO x - and particulate emissions are largely avoided. Advantages over operation with hydrogen or LNG lie particularly in the simpler and safer storage and handling of methanol.

[0009] According to one embodiment of the method, the propulsion engine is a diesel engine capable of running on methanol. This is preferably the diesel engine that was already installed in the dry cargo ship before its conversion to methanol operation. In this embodiment, the diesel engine is optionally optimized for methanol operation by modifying settings or other simple measures. According to another embodiment, the propulsion engine is a diesel engine that has been converted to run on methanol. This is preferably the diesel engine that was already installed in the dry cargo ship before its conversion to methanol operation, or a diesel engine from another dry cargo ship of the same or a similar type. Alternatively, it can be any diesel engine that has been converted for methanol operation.According to another design, the diesel engine installed in the dry cargo ship before the conversion is replaced by an internal combustion engine that can run on methanol. This can preferably be an internal combustion engine specifically designed or engineered for operation with methanol.

[0010] According to another embodiment, the drive engine is a diesel engine equipped with a cylinder head featuring methanol injectors in addition to, or instead of, diesel injectors. If the diesel engine is equipped with methanol injectors in addition to diesel injectors, it can also be operated in mixed mode with methanol and diesel. The mixing ratios of methanol and diesel are, in principle, arbitrary. Preferably, diesel is added to the drive engine for ignition, whereby the proportion of added diesel can be small. Preferably, a maximum of 10 wt% diesel is added, and more preferably, 3 to 5 wt% diesel is added when the diesel engine is operated in mixed mode. Alternatively, the drive engine is equipped with methanol injectors instead of diesel injectors to operate the diesel engine exclusively on methanol.The diesel engine in question may be, in particular, the diesel engine installed in the dry freighter before its conversion to operation with methanol, or a diesel engine of the same or similar design from another dry freighter.

[0011] According to one embodiment of the method, the methanol unit comprises a methanol system with one or more of the following components: components for conveying methanol from the methanol tank to the drive engine (e.g., a feed pump), measuring devices for methanol consumption, and measuring devices for determining the indicated engine power of the drive engine. According to another embodiment, the methanol system is connected to the drive engine via at least one fuel line. According to yet another embodiment, the fuel line is connected to the injectors of a diesel engine.

[0012] According to another embodiment, the methanol unit has an inerting system with at least one nitrogen cylinder, which is connected via at least one gas line to the methanol tank and / or a hollow casing of at least one fuel line. The inerting system allows cavities to be filled with inert gas to prevent the accumulation of explosive gas mixtures.

[0013] According to another embodiment, the methanol unit includes a diesel system for supplying the diesel engine with diesel fuel. This diesel system is connected to a diesel tank in the stern and to the diesel engine. The diesel system controls the supply of diesel fuel to the diesel engine in addition to the methanol. For this purpose, the diesel system is connected via at least one fuel line to the diesel tank already present in the stern and to the diesel injectors of the diesel engine. According to another embodiment, the diesel system includes one or more of the following components: components for pumping diesel fuel from the diesel tank to the diesel engine (e.g., a fuel pump), measuring devices for methanol consumption, and measuring devices for determining the indicated engine power of the diesel engine.

[0014] In another design, at least one methanol tank is installed transversely to the ship's axis in the rear section of the cargo hold. This arrangement results in minimal loss of cargo space.

[0015] According to another embodiment, exactly two methanol tanks, preferably two methanol tanks arranged side by side in the transverse direction of the ship, are installed in the aft section of the cargo hold. One methanol tank can be used as a reserve tank. Furthermore, the two methanol tanks can be used for trimming the ship.

[0016] According to another embodiment, the methanol system and / or the inerting system and / or the diesel system is arranged between two adjacent methanol tanks. This is advantageous for a symmetrical weight distribution and for connecting the various systems to the methanol tanks and the fuel lines.

[0017] In another embodiment, the methanol unit is installed as a complete structural unit in the cargo hold, preferably using a crane. The methanol unit comprises at least one methanol tank. Optionally, the methanol unit also includes the methanol system and / or the inerting system and / or the diesel system. Installing the methanol unit as a structural unit in the cargo hold greatly simplifies the conversion process and allows it to be completed quickly. The complete methanol unit can be manufactured separately at a production facility, transported to the ship, and installed in the cargo hold. Due to the largely identical structural design of dry cargo vessels, a wide variety of ships can be equipped with the same type of methanol unit. Furthermore, it is possible to remove the methanol unit as a structural unit from the dry cargo vessel.As an alternative to constructing the methanol unit as a single structural unit, the components of the methanol unit are installed separately and / or in smaller pre-assembled modules in the dry cargo ship.

[0018] According to another embodiment, the methanol unit has dimensions of 8 m width (in the transverse direction of the ship), 4 m height and 1.5 m length (in the longitudinal direction of the ship) and / or the at least one tank has a capacity of 36 m³ 3 The dimensions are designed to largely match the cargo hold dimensions of dry cargo ships. The tank volume is designed to match the loading capacity of common tank trucks that can refuel the dry cargo ships.

[0019] In another design, an additional transverse bulkhead is installed in the cargo space in front of the methanol unit. This isolates the cargo space from the methanol tanks and increases safety.

[0020] To further enhance safety, the rear section of the cargo hold containing the methanol unit is covered by a lid extending from the engine front bulkhead to the additional transverse bulkhead. In another embodiment, the rear section of the cargo hold between the engine front bulkhead and the transverse bulkhead is equipped with forced ventilation, ensuring a specific air exchange rate in the rear of the cargo hold.

[0021] According to another design, the lid has an opening hatch through which the rear area of ​​the cargo space is accessible for carrying out inspections, maintenance or repairs.

[0022] 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.

[0023] Preferably, no diesel fuel or diesel fuel in small proportions of a maximum of 10% by weight, preferably 3 to 5% by weight, is added as an ignition medium for the operation of the diesel engine. However, it is also possible in principle to use diesel and methanol in any mixture ratio, since the diesel engine can still be operated with diesel fuel after the conversion. The diesel tank can therefore also be used, for example, as a reserve tank for the operation of the dry cargo ship.

[0024] According to another version, green or grey methanol is used to operate the diesel engine.

[0025] The invention will not be explained in further detail below with reference to the accompanying drawings of an exemplary embodiment. 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 ( Fig. 1c) and a horizontal longitudinal section through the engine room ( Fig. 1d); Fig. 2a-c the rear area of ​​the cargo hold of the dry freighter with built-in methanol unit in a vertical longitudinal section, a vertical cross section and a horizontal longitudinal section, each in an enlarged partial view.

[0026] According to Fig. Figure 1 comprises a dry cargo ship 1 with a diesel engine for inland navigation, a slender hull 2 ​​with a flat bottom 3. The dry cargo ship 1 has a short bow 4, a slightly longer stern 5, and an elongated midship section 6 with an open-topped cargo hold 7. In the area of ​​the cargo hold 7, the side walls 8, 9 of the ship are designed as ballast tanks 10, 11 for ballast water.

[0027] The stern section 5 includes an engine room 12, a shaft system 13, a rudder system 14, a deckhouse 15 with a funnel 16 and a raising and lowering bridge 17.

[0028] Engine room 12 contains the main engine (designed as a diesel engine 18), auxiliary diesel engines 19 and 20 for generating electricity, a heating system 21, and a hydraulic system 22 for the rudder system 14. The shaft system 13 is connected to the main engine 18.

[0029] Below the engine room 12, in the ship's bottom 3, there is another ballast tank 23, and on both sides of the engine room are trim tanks 24, 25.

[0030] By filling or emptying the ballast and trim tanks 10, 11, 23, 24, 25, the ship's height can be adjusted and the position of the dry freighter 1 in the water can be changed, for example to allow passage under bridges or to compensate for an uneven distribution of the ship's cargo. Bridge 17 can also be lowered for bridge passages.

[0031] In the conversion according to the invention, the entire engine is replaced with an engine that can be operated exclusively with methanol, or with methanol and diesel and / or another fuel, or the cylinder head 26 of the diesel engine 18 is provided with injectors for methanol in addition to the injectors for diesel. For this purpose, either the originally existing cylinder head 26 has been replaced by a modified or a new cylinder head with injectors for methanol and diesel, or the original cylinder head has been additionally provided with injectors for methanol.

[0032] The engine room 12 is closed off at the front by a transversely running engine front bulkhead 27.

[0033] According to Fig.2. Directly forward of the engine bulkhead 27, a methanol unit 28 is installed in the cargo hold 7. The methanol unit 28 is a structural unit that is essentially box-shaped, with a width (in the transverse direction of the ship) of 8 m, 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 cargo hold 7.

[0034] 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 identical filling volumes, for example, 18 m³ each. 3 The total is 36 m. 3 .

[0035] Between the two methanol tanks 28, 30, the methanol unit 28 has a compartment 31 in which a methanol system 32, an inerting system 33 and, optionally, 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 methanol consumption, and measuring devices for determining the indicated engine power.

[0036] The inerting system 33 comprises gas cylinders 35, valves, and (inert) gas lines to the methanol tanks 29, 30, as well as to hollow jackets around fuel lines to the diesel engine. Nitrogen or another inert gas can be pumped into the methanol tanks or the jackets and fuel lines by means of the inerting system 33 to prevent an explosion caused by the accumulation of small amounts of gas.

[0037] The diesel system 34 comprises components for supplying the diesel engine 18 with diesel (e.g., fuel 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 be operated exclusively on methanol or is replaced by an internal combustion engine that can be operated exclusively on methanol.

[0038] The methanol tanks 29, 30 can be made of steel and / or plastic.

[0039] The methanol unit 28 can be designed such that the methanol tanks 29, 30 form the supporting structure for the systems 32, 33, 34, particularly if the methanol tanks 29, 30 are made of steel. However, it is also possible to use a frame, e.g., made of steel, as the supporting structure of the methanol unit 28, for example, to hold methanol tanks 29, 30 made of plastic and the systems 32, 33, 34 within them.

[0040] The methanol unit 28 is inserted into the cargo hold 7 with the aid of a crane (e.g. a mobile crane) and connected to the ship's hull 2 ​​by welding, bolting or other fastening methods.

[0041] The methanol unit 28 can be installed in cargo hold 7 without having to take the ship to a shipyard.

[0042] After the methanol unit 28 is installed in the cargo compartment 7, it is connected via fuel lines to the methanol and diesel injectors of the diesel engine 18. Furthermore, the methanol unit 28 is connected via data cables to the diesel engine 18 and / or the bridge 17 in order to control the methanol and diesel systems 32, 34 depending on the desired engine output.

[0043] Directly in front of the methanol unit 28, an additional transverse bulkhead 36 is welded into the cargo compartment 7. The area of ​​the cargo compartment 7 between the engine front bulkhead 27 and the additional transverse bulkhead 36 is covered by a screwed-in cover 37. The space between the engine front bulkhead 27, the additional transverse bulkhead 36, and the cover 37 is forced-ventilated.

[0044] The compartment 31 can be accessed for inspection, maintenance and repair of the methanol system 32, inerting system 33 and diesel system 34 via an opening hatch 38 in the lid 37. A ladder 39 is built into the compartment 31 for this purpose.

[0045] Hatch covers 40 for covering the cargo space 7 can be moved up to over the cover 37.

[0046] The two methanol tanks 29, 30 have tank nozzles that extend through the two side walls of the ship's hull 2 ​​to the outside.

[0047] Only a very small part of the cargo space 7 is lost for the installation of the methanol unit 28.

[0048] The methanol unit 28 can also be easily removed from the ship's hull.

Claims

[1] Method for converting a dry cargo ship with a diesel engine as its propulsion engine to operation 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 front bulkhead. [2] Method according to claim 1, wherein the drive engine is a diesel engine capable of running on methanol or is converted to a diesel engine capable of running on methanol or is replaced by an internal combustion engine capable of running on methanol. [3] Method according to claim 1 or 2, wherein the drive engine is a diesel engine equipped with a cylinder head with injectors for methanol in addition to or instead of injectors for diesel. [4] Method according to any one of claims 1 to 3, wherein the methanol unit is connected to the drive motor via at least one fuel line. [5] Method according to any one of claims 1 to 4, wherein 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 motor, measuring devices for methanol consumption, measuring devices for determining the indicated motor power of the drive motor. [6] Method according to claim 5, wherein the methanol system is arranged between two methanol tanks arranged side by side. [7] Method according to any one of claims 1 to 6, wherein 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. [8] Method according to claim 7, wherein the inerting system is arranged between two methanol tanks arranged side by side. [9] Method according to any one of claims 1 to 8, wherein the methanol unit comprises a diesel system for supplying the diesel engine with diesel. [10] Method according to claim 9, wherein the diesel system is arranged between two methanol tanks arranged side by side. [11] Method according to claim 9 or 10, wherein the diesel system is connected to a diesel tank in the stern and to the diesel engine via at least one fuel line. [12] Method according to any one of claims 1 to 11, wherein the at least one methanol tank is installed in the rear area of ​​the cargo hold in a transverse direction to the ship's axis. [13] Method according to any one of claims 1 to 12, wherein two methanol tanks, preferably two methanol tanks arranged side by side in the transverse direction of the dry cargo ship, are installed in the rear area of ​​the cargo hold. [14] Method according to any one of claims 1 to 13, wherein the methanol unit is inserted into the cargo space as a structural unit. [15] Method according to any one of claims 1 to 14, wherein the methanol unit has dimensions of about 8 × 4 × 1.5 m and / or wherein the at least one tank has a capacity of 36 m³ 3 exhibits. [16] Method according to any one of claims 1 to 15, wherein an additional transverse bulkhead is installed in the cargo space in front of the methanol unit. [17] Method according to claim 16, wherein the rear area of ​​the cargo space containing the methanol unit is covered by a cover extending from the engine front bulkhead to the additional transverse bulkhead. [18] Method according to claim 17, wherein the lid has a hatch that can be opened. [19] Method for operating a dry cargo ship converted according to any one of claims 1 to 18, wherein the propulsion engine is operated simultaneously with methanol from the methanol tank and diesel from the diesel tank. [20] Method according to claim 19, wherein the proportion of diesel in the total fuel injected into the drive engine is a maximum of 10 wt.%, preferably 3 to 5 wt.%. [21] Method according to claim 19 or 20, wherein green or grey methanol is used for the operation of the drive motor.

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