Large methanol power container ship tank fuel system and method

Abstract

The invention belongs to the technical field of ships, and discloses a tank fuel system and method for a large methanol power container ship. The system comprises a methanol tank box, a fuel cabin, a lightering pump, a booster pump, a heating unit and a pipeline interface. The invention mainly aims to adopt a methanol tank box as a'movable fuel cabin 'of the methanol power container ship, so that the waste of effective space of the ship caused by building a large fuel cabin by the container ship is effectively avoided. Meanwhile, compared with a traditional fuel cabin filling mode, the methanol tank box is more convenient to load compared with a fuel cabin filling mode. Besides, based on two important variables of container freight and methanol fuel cost, loading and unloading of methanol tanks and containers are carried out at different ports, and scientific stowage of the quantitative relation between the methanol tanks and the containers is realized in the limited space of a container ship, so that the income of the ship is maximized.

Description

Technical Field

[0001] The invention belongs to the technical field of ships, and in particular relates to a tank fuel system and method for a large methanol-powered container ship. Background Art

[0002] As the International Maritime Organization (IMO) sets increasingly strict standards for ship emissions, traditional marine fuel can no longer meet the requirements. Methanol as marine fuel produces less CO2 when burned and has relatively mild physical and chemical properties. It has gradually become an ideal new alternative fuel for many ships, especially large container ships.

[0003] Methanol is liquid at room temperature and pressure. Compared with LNG, ammonia and other fuels, it is easier to store or transport. However, the calorific value of methanol is about 19.6MJ / kg and the density is about 791kg / m 3 The calorific value of traditional fuel oil is about 43MJ / kg and the density is about 980kg / m 3 If the same calorific value is achieved, the volume of methanol fuel required is about 2.6 times that of traditional fuel, that is, the volume of a methanol ship's fuel tank is about 2.6 times that of a traditional fuel ship's fuel tank.

[0004] A container ship is a full-container ship whose cargo holds and decks are dedicated to loading containers. Container ships have large hulls, fast speeds, and very high propulsion power. Therefore, container ships need to carry more fuel, so the fuel tanks of container ships are very large. As we all know, with the development of large-scale container ships, more containers need to be placed. Therefore, both the cargo hold space inside the hull and the space on the deck are particularly precious. Fuels with special properties such as methanol and LNG, which have low flash points and are flammable and explosive, cannot be placed in the double bottom of the hull or other "corners" of the hull like traditional fuel oil. Instead, they are set in the relatively open effective space in the hull, which is not prone to collisions, etc., and are usually set below the superstructure of the ship. However, the calorific value of methanol is low, which means that the volume of the fuel tank is larger. It is far from enough to set the fuel tank just below the superstructure of the ship. It also needs to be extended to the cargo hold, causing the fuel tank to occupy a larger effective space of the ship, which seriously affects the capacity of large container ships. Therefore, large methanol container ships face the problem of fuel storage occupying too much effective space in the hull.

[0005] There is a type of container that can be placed on a container ship to store liquids called a tank container, also known as a "tank container". If a tank container is used to load methanol fuel, it can be lifted, stored, and transported at the container terminal, which is very convenient and can realize flexible loading and unloading of container ships. Therefore, based on these advantages of methanol tank containers, it is possible to consider using methanol tank containers as the "mobile fuel tank" of container ships.

[0006] Container ships sail long distances and can call at many ports during their voyages. During long-distance voyages, they need to refill fuel tanks or hoist methanol tank containers to replenish methanol fuel while calling at ports. Since each port is usually located in a different country and has different conditions, the corresponding methanol prices are often different. Container ship cargo boxes often carry different goods. Due to the different types of goods in the cargo boxes and the distances of cargo box transportation, the cargo box freight is also different. Therefore, when container ships load methanol tank containers and cargo boxes at different ports, the price of methanol fuel is usually different, and the cargo box freight is also different.

[0007] In view of the above problems, the present invention proposes a tank fuel system and method for a large-scale methanol-powered container ship. In addition to its own inherent fuel tank, the container ship also uses a methanol tank as a "mobile fuel tank" of the container ship, and loads methanol tanks and cargo containers at different ports. Based on the difference in cargo container freight and methanol prices, the effective space of the container ship is fully utilized, and based on the two important variables of cargo container freight and methanol fuel cost, the quantity relationship between the container ship cargo containers and methanol tanks is scientifically loaded to maximize the ship's revenue. Summary of the invention

[0008] In view of the above-mentioned problems, the purpose of the present invention is to propose a tank fuel system and method for a large methanol-powered container ship.

[0009] The first object of the present invention is to provide a large-scale methanol-powered container ship tank fuel system, which mainly includes a methanol tank, a fuel tank, a transfer pump, a booster pump, a heating unit, and a pipeline interface.

[0010] The methanol tank is provided with a pipeline interface, which can be connected to the pipeline, and the methanol tank is connected to the booster pump, the heating unit, and the power device in sequence through the pipeline. The transfer pump is located in the fuel tank and is connected to the booster pump, the heating unit, and the power device in sequence through the pipeline.

[0011] The fuel tank of the container ship is located under the superstructure, and the methanol tank container is placed in a wide and specific position on the deck of the container ship, which can be used to place methanol tank containers or cargo containers. The methanol tank container is as close to the engine room as possible, and the total amount of methanol in the fuel tank and the methanol tank container must ensure that the container ship can arrive at the next refueling port normally.

[0012] In this system, the methanol tank is just a container for storing methanol.

[0013] The booster pump and the heating unit are located in an air supply chamber in the fuel processing room on the ship deck.

[0014] In this system, the methanol fuel for the power unit mainly comes from two sources: one is the methanol in the fuel tank; the other is the methanol in the methanol tank. When the container ship is sailing, if there is a methanol tank on board, the methanol in the methanol tank will be used first; after the methanol tank is used up, the methanol in the fuel tank will be used.

[0015] During the voyage of the ship, the process of the methanol tank supplying the power unit is as follows: the methanol in the methanol tank enters the pipeline through the pipeline interface and is transported to the booster pump. The methanol reaches a suitable pressure under the action of the booster pump, and then the methanol is heated to the supply temperature in the heating unit and finally supplied to the power unit.

[0016] The process of supplying the power unit with the fuel tank is as follows: the methanol in the fuel tank is pumped out by the transfer pump through the pipeline into the booster pump, the methanol reaches a suitable pressure under the action of the booster pump, and then the methanol is heated to the supply temperature in the heating unit, and finally used by the power unit.

[0017] The second purpose of the present invention is to propose a method for tank fuel of large methanol-powered container ships based on the above system. This method not only scientifically and fully utilizes the effective space of large methanol-powered container ships, but also uses methanol tanks as the "mobile fuel tanks" of container ships. A model of cargo container freight and methanol fuel costs is established. Through this model, cargo containers and methanol tanks are scientifically loaded before loading at the port, and the quantitative relationship between cargo containers and methanol tanks is determined to maximize the revenue of the ship.

[0018] In the present invention, for the built ships, the main income comes from the container freight C 运 Since the container ship has limited space, the number of methanol tanks loaded will directly affect the number of cargo containers loaded (the number of cargo containers loaded will decrease), which will directly affect the ship's revenue. However, other expenses of the ship, such as ship investment, crew salaries, maintenance costs, etc., have no direct impact on the ship's revenue. Therefore, the model of this invention mainly focuses on the freight C 运 and methanol fuel cost C 燃 Two important variables are discussed.

[0019] The methanol fuel cost is C 燃 Including methanol fuel cost in the fuel tank C 舱燃 and methanol fuel cost C in methanol tank 罐燃 .

[0020] Assume that the departure port of this container ship is Port A, and it passes through Ports B, C, ...X, Y, and Z. The fuel tank is filled with methanol fuel at the departure port A. During the voyage, due to the long voyage distance, the fuel tank is filled with methanol fuel at the intermediate port, and the methanol fuel cost C in the fuel tank is obtained. 舱燃 , expressed by formula (I):

[0021]

[0022] Among them, M 舱 M is the capacity of methanol fuel in the fuel tank. When a methanol container ship sails on a certain route, the capacity of its fuel tank is fixed. 舱 is a fixed value; P 燃A is the price of methanol in port A; K α is the loading rate of the fuel tank at port α, which is the percentage of methanol fuel added to the fuel tank at port α to the total capacity of the fuel tank; P 燃α is the methanol price at bunkering port α; The filling coefficient refers to whether the port has the conditions to fill the fuel tank with methanol fuel. No refill conditions

[0023] Methanol fuel cost in methanol tank container C 罐燃 It is expressed by formula (II):

[0024]

[0025] Where α=A, B…X, Y, Z represent different ports, N 罐α is the number of methanol tank containers loaded at port α; M 罐 is the capacity of methanol fuel in the methanol tank. The capacity of the methanol tank is fixed, so M 罐 Is a fixed value.

[0026] The total cost of methanol fuel C 燃 The methanol fuel cost C in the fuel tank 舱燃 and methanol fuel cost C in methanol tank 罐燃 The sum of is represented by formula (III):

[0027] C 燃 =C 舱燃 +C 罐燃 (III)

[0028] Cargo box freight C 运 It is equal to the product of the number of containers N and the container freight rate P, and the container freight rate P is related to the type of container and the transportation distance. The overall formula is expressed by (IV):

[0029]

[0030] In formula (IV), α = A, B...X, Y, Z represent different ports; β = 1, 2, 3...n represent different cargoes, N βα represents the number of containers of cargo β at port α; P βα It represents the container freight rate of cargo β at port α.

[0031] in It means the total freight cost of delivering cargo 1 to one or more ports among ports B, C…Z;

[0032] It represents the total freight cost of delivering cargo 2 to one or more ports among ports B, C…Z;

[0033] And so on. It represents the total freight cost of delivering cargo n to one or more ports among ports B, C...Z.

[0034] In summary, the total revenue of the ship is C 总 It is made by C 运 and C 燃 The total formula of this method is represented by (V). Then, to maximize the total revenue of the ship, that is, C 运 and C 燃 The difference is the largest.

[0035] C 总 =C 运 -C 燃 (V)

[0036] For practical reasons, the total revenue of the ship is maximized. 总max Two prerequisites need to be met: one is the relationship between the number of cargo containers and methanol tank containers on the container ship. Regardless of the port, the sum of the number of cargo containers and methanol tank containers loaded must be less than or equal to the maximum total number of containers on the container ship, as expressed by formula (VI); the other is the relationship between methanol fuel and sailing distance. It is necessary to ensure that methanol fuel can enable the container ship to reach the next port of call where methanol fuel can be refueled or methanol tank containers can be loaded, as expressed by formula (VII).

[0037]

[0038] In formula (VI), δ is a port among A, B, ..., X, Y, Z; N 货δ is the number of cargo containers in port δ; N 罐δ is the number of methanol tanks in δ port; N 总 The maximum total number of containers on a container ship.

[0039] In formula (VII): N * is a port from A to Z where methanol fuel can be refueled or methanol tank containers can be loaded, and γ is A, B, C…N * -1 port; α=A, B…X, Y, Z represent different ports; K α M is the loading rate of the fuel tank at port α, which is the percentage of methanol fuel added to the fuel tank at port α to the total capacity of the fuel tank; 舱M is the capacity of methanol fuel in the fuel tank. When a methanol container ship sails on a certain route, the capacity of its fuel tank is fixed. 舱 is a fixed value; The filling coefficient refers to whether the port has the conditions to fill the fuel tank with methanol fuel. No refill conditions M 罐 is the capacity of methanol fuel in the tank. The capacity of the methanol tank is fixed, so M 罐 is a fixed value; N 罐γ is the number of methanol tanks in port γ; μ is the richness coefficient of methanol fuel, which is generally 1.1-1.2; λ is the average daily consumption of methanol fuel; V 平 is the average speed; S A,γ+1 It is the distance from the departure port A to a port where methanol fuel can be refueled or methanol tank containers can be loaded.

[0040] The departure port of the container ship is Port A, and it passes through Ports B, C, ... X, Y, and Z. During the voyage, the ship fills the fuel tank with methanol or loads methanol tank containers at some of the ports. Based on the different methanol fuel prices at the ports and the quantity relationship between methanol tank containers and cargo containers, in order to minimize the cost of filling methanol fuel, the methanol fuel cost is calculated according to Formulas (I), (II), and (III) based on the actual situation and on the premise of Formulas (VI) and (VII).

[0041] The departure port of the container ship is Port A, passing through Ports B, C, ... X, Y, and Z. In this process, the goods can be transported from one port to other ports according to different demands. Considering that the methanol fuel in the ship in Formula (VII) can reach the next port of call that can load methanol tank containers, the ship has a certain number of methanol tank containers. According to this model, the quantitative relationship between the cargo containers and the methanol tank containers is determined so that the cargo container freight can obtain the maximum profit. Under the premise of Formula (VI) and Formula (VII), the cargo container freight is calculated according to Formula (IV).

[0042] According to the four actual situations of container ships during navigation, the total revenue C of the ship is calculated according to the four actual situations. 总 :

[0043] Case 1: The quantity relationship formula (VI) between cargo containers and methanol tank containers is met. The container space is sufficient and the methanol fuel in the fuel tank can sail the entire journey. There is no need to refill the fuel tank with methanol fuel at the intermediate port, and there is no need for methanol tank containers to serve as the "mobile fuel tank" of the container ship. According to formula (I), the methanol fuel cost C in the fuel tank is calculated 舱燃 、Formula (Ⅳ) calculates the container freight C 运 、Formula (V) calculates the total revenue C of the ship 总 .

[0044] Case 2: The quantitative relationship formula (VI) between cargo containers and methanol tank containers is satisfied. There is sufficient space for cargo containers but the methanol fuel in the fuel tank cannot support the entire voyage. In this case, methanol tank containers are needed as the "mobile fuel tank" of the container ship. The lifting of methanol tank containers is more convenient than filling the fuel tank. Since there is sufficient space for cargo containers, methanol tank containers are mainly used as fuel. According to formula (I), the cost of methanol fuel in the fuel tank is calculated as C 舱燃 、Formula (Ⅳ) calculates the container freight C 运 、Formula (V) calculates the total revenue C of the ship 总 .

[0045] Case 3: The quantitative relationship formula (VI) between cargo containers and methanol tank containers is not satisfied. The number of container ship slots is insufficient. The methanol fuel fills the fuel tank at the departure port and needs to be replenished at the intermediate port. The container ship can sail the entire journey with all the slots filled with cargo containers. Calculate the methanol fuel cost C of the fuel tank according to formula (I) 舱燃 、Formula (Ⅳ) calculates the container freight C 运 、Formula (V) calculates the total revenue C of the ship 总 .

[0046] Case 4: The quantitative relationship formula (VI) of cargo containers and methanol tank containers is not satisfied. The number of container ship slots is insufficient. If the methanol in the fuel tank cannot travel to the next refueling port, the methanol tank container can be used as the "mobile fuel tank" of the container ship to ensure that the container ship can reach the next refueling port. If the remaining slots after loading the methanol tank container cannot accommodate all cargo containers, a batch of low-profit cargo can be discarded according to the actual situation. The abandoned slots can be compared with the methanol price and cargo container freight, and then the quantitative relationship between cargo containers and methanol tank containers in the remaining slots can be scientifically loaded. Calculate the methanol fuel cost C in the fuel tank according to formula (I) 舱燃 、Formula (Ⅱ) calculates the methanol fuel cost C in the methanol tank 罐燃 、Formula (Ⅳ) calculates the container freight C 运 、Formula (V) calculates the total revenue C of the ship 总 .

[0047] The above method describes the calculation method of methanol fuel costs and container freight for a container ship's one-way trip from Port A to Port Z. The calculation method of methanol fuel costs and container freight for the trip from Port Z back to Port A is the same as above.

[0048] Beneficial effects of the present invention:

[0049] 1. The present invention adopts methanol tanks as the "mobile fuel tank" of the methanol-powered container ship, which not only avoids the waste of effective space of the ship caused by building a "fixed fuel tank" that is too large for the container ship, but also makes loading and unloading methanol tanks more convenient than filling the fuel tank.

[0050] 2. The method of the present invention is based on two important variables, namely, container freight and methanol fuel cost, and loads methanol tank containers and cargo containers at different ports. In the limited space of a container ship, the method of the present invention realizes scientific loading of the quantity relationship between methanol tank containers and cargo containers, thereby maximizing the ship's revenue. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a system diagram of the present invention

[0052] Figure 2 Schematic diagram of the methanol tank box of the present invention

[0053] Figure 3 It is a schematic diagram of the cargo box of the present invention

[0054] Figure 4 This is a schematic diagram of the positions of the cargo box and the methanol tank box on the container ship in the present invention.

[0055] Figure 5 Fuel filling diagram

[0056] Figure 6 It is a diagram of cargo box transportation

[0057] Figure 7 This is a diagram of the comparison of container freight rates.

[0058] Figure 8 This is a diagram of the optimization and adjustment of container freight and methanol fuel prices.

[0059] In the attached figure: 1. Methanol tank; 2. Fuel tank; 3. Transfer pump; 4. Booster pump; 5. Heating unit; 6. Cargo box; 7. Lashing bridge; 8. Pipeline interface DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0061] The first object of the present invention is to propose a large methanol powered container ship tank fuel system based on the above problems. Figure 1 As shown, the present invention includes 1, a methanol tank box 2, a fuel tank 3, a transfer pump 4, a booster pump 5, a heating unit 8, and a pipeline interface.

[0062] The methanol tank is provided with a pipeline interface 8, which can be connected to the pipeline, and the methanol tank is connected to the booster pump 4, the heating unit 5, and the power device in sequence through the pipeline. The transfer pump 3 is located in the fuel tank 2 and is connected to the booster pump 4, the heating unit 5, and the power device in sequence through the pipeline.

[0063] During the voyage of the ship, Figure 1The process of supplying the power unit with the methanol tank 1 is as follows: the methanol in the methanol tank 1 enters the pipeline through the pipeline interface 8 and is transported to the boost pump 4. The methanol reaches a suitable pressure under the action of the boost pump 4, and then the methanol is heated to the supply temperature in the heating unit 5, and finally supplied to the power unit.

[0064] like Figure 1 The process of supplying the power unit from the fuel tank 2 is as follows: the methanol in the fuel tank 2 is pumped out by the transfer pump 3 and enters the booster pump 4 through a pipeline. The methanol reaches a suitable pressure under the action of the booster pump 4, and then the methanol is heated to the supply temperature in the heating unit 5, and finally supplied to the power unit.

[0065] like Figure 4 As shown, the fuel tank 2 of the container ship is placed under the superstructure, and the methanol tank 1 is placed in a specific position in the open space of the deck of the container ship. The position can be used to place the methanol tank 1 or the cargo box 6. The methanol tank 1 is as close to the engine room as possible. The total amount of methanol fuel in the fuel tank 2 and the methanol tank 1 must ensure that the methanol fuel can reach the next refueling port normally. A certain number of methanol tanks 1 need to be placed in this position, and the cargo box 6 is placed in other positions of the container ship. The term "position" in the present invention refers to the position where the container is placed. For example, if 20,000 TEUs are carried, there are 20,000 container positions.

[0066] like Figure 2 As shown, in this system, the methanol tank 1 is only a container for storing methanol fuel.

[0067] The boosting pump 4 and the heating unit 5 are located in an air supply room in the fuel processing room on the ship deck.

[0068] like Figure 4 As shown, the methanol tank container 1 is placed in a designated area on the deck. The designated area can be determined according to the actual size of the ship, not just as shown in the figure. However, in order to reduce the length of the arranged pipelines, the area should be as close to the engine room as possible. In addition, in order to facilitate the ship's personnel to manage the methanol tank container 1, the methanol tank container 1 is generally placed on the first to third floor of the designated area. While ensuring that the methanol tank container 1 is placed first, the space above the third floor and the extra spaces on the third floor and below in this area can still be used to place cargo boxes 6. The schematic diagram of the cargo box is shown in Figure 3 shown.

[0069] In this system, the methanol fuel for the power unit mainly comes from two sources: one is the methanol in the fuel tank 2; the other is the methanol in the methanol tank 1. When the container ship is sailing, if there is a methanol tank 1 on board, the methanol in the methanol tank 1 will be used first. After the methanol tank 1 is used up, the methanol in the fuel tank 2 will be used.

[0070] The fuel tank 2 is the "inherent fuel tank" of the ship. Its size cannot be changed after the ship is built. A large methanol-powered container ship requires a larger fuel tank 2. Building a fuel tank 2 that is too large will affect the cargo capacity of the ship. The number of methanol tanks 1 on a container ship can be more or less, and it is convenient to load and unload and use, and can be used as a "mobile fuel tank" for a container ship. The present invention uses a methanol tank 1 as a "mobile fuel tank" outside a methanol-powered container ship. It not only avoids the waste of effective space of the ship caused by building a fuel tank 2 that is too large for the container ship. Moreover, loading a methanol tank 1 is more convenient than filling a fuel tank 2.

[0071] The second purpose of the present invention is to propose a method for tank fuel of large methanol-powered container ships based on the above system. This method not only scientifically and fully utilizes the effective space of large methanol-powered container ships, but also uses methanol tanks as the "mobile fuel tanks" of container ships. In addition, a model of cargo container freight and methanol fuel costs is established. Through this model, the ship is scientifically loaded, the quantitative relationship between cargo containers and methanol tanks is determined, and the ship's revenue is maximized.

[0072] In this method, the containers on the container ship mainly include two types, one is the cargo box, and the other is the methanol tank box. Because the large methanol-powered container ship requires a large fuel tank, and an oversized fuel tank will occupy more effective space of the ship, the methanol tank box is used as the "mobile fuel tank" of the container ship. Using the methanol tank box as the "mobile fuel tank" of the container ship, the methanol fuel in the methanol tank box will be burned during the voyage, so that a certain amount of methanol tank boxes will be loaded at different ports of call. The methanol fuel cost of each port is different based on its own conditions, and the methanol fuel is stored in the methanol tank box. The corresponding price of the methanol tank box at each port of call is also different. The various types of cargo boxes carried by the container ship have different corresponding cargo box freight rates due to different types of cargo boxes and transportation distances. However, the number of containers on the container ship is fixed. If the methanol tank box is loaded with more, the cargo box will be loaded with less.

[0073] In the present invention, for the built ships, the main income comes from the container freight C 运 Since the container ship has limited space, the number of methanol tanks loaded will directly affect the number of cargo containers loaded (the number of cargo containers loaded will decrease), which will directly affect the ship's revenue. However, other expenses of the ship, such as ship investment, crew salaries, maintenance costs, etc., have no direct impact on the ship's revenue. Therefore, the model of this invention mainly focuses on the freight C 运 and methanol fuel cost C 燃 Two important variables are discussed.

[0074] The methanol fuel cost is C 燃 Including methanol fuel cost in the fuel tank C 舱燃and methanol fuel cost C in methanol tank 罐燃 .

[0075] Assume that the departure port of this container ship is Port A, and it passes through Ports B, C, ...X, Y, and Z. The fuel tank is filled with methanol fuel at the departure port Port A. During the voyage, due to the long voyage distance, the fuel tank will be refilled with methanol fuel at the intermediate port, and the methanol fuel cost C in the fuel tank is obtained. 舱燃 , expressed by formula (I):

[0076]

[0077] Among them, M 舱 M is the capacity of methanol fuel in the fuel tank. When a methanol container ship sails on a certain route, the capacity of its fuel tank is fixed. 舱 is a fixed value; P 燃A is the price of methanol in port A; K α is the loading rate of the fuel tank at port α, which is the percentage of methanol fuel added to the fuel tank at port α to the total capacity of the fuel tank; P 燃α is the methanol price at bunkering port α; The refueling coefficient refers to whether the port has the conditions for refueling methanol fuel. No refill conditions

[0078] Methanol fuel cost in methanol tank container C 罐燃 It is expressed by formula (II).

[0079]

[0080] Where α=A, B…X, Y, Z represent different ports, N 罐α M is the number of methanol tanks loaded at port α; 罐 is the capacity of the fuel in the tank. The capacity of the methanol tank is fixed, so M 罐 is a fixed value; P 燃α is the price of methanol fuel in α port.

[0081] The total cost of methanol fuel C 燃 The methanol fuel cost C in the fuel tank 舱燃 and methanol fuel cost C in methanol tank 罐燃 It is composed of the sum of and is expressed by formula (III).

[0082] C 燃 =C 舱燃 +C 罐燃 (III)

[0083] Cargo box freight C 运It is equal to the product of the number of containers N and the container freight rate P, and the freight rate P is related to the type of container and the transportation distance. The overall formula is represented by (IV);

[0084]

[0085] In formula (IV): α = A, B...X, Y, Z represent different ports; β = 1, 2, 3...n represent different cargoes; N βα represents the number of containers of cargo β at port α; P βα It represents the container freight rate of cargo β at port α.

[0086] in It means the total freight cost of delivering cargo 1 to one or more ports among ports B, C…Z;

[0087] It represents the total freight cost of delivering cargo 2 to one or more ports among ports B, C…Z;

[0088] And so on. It represents the total freight cost of delivering cargo n to one or more ports among ports B, C...Z.

[0089] In summary, the total revenue of the ship is C 总 It is made by C 运 and C 燃 The total formula of this method is represented by (V). Then, to maximize the total revenue of the ship, that is, C 运 and C 燃 The difference is the largest.

[0090] C 总 =C 运 -C 燃 (V)

[0091] For practical reasons, the total revenue of the ship is maximized. 总max Two prerequisites need to be met: one is the quantitative relationship between cargo containers and methanol tank containers on the container ship, which is expressed by formula (VI). No matter which port in δ, the sum of the number of methanol tank containers and the number of cargo containers must be less than or equal to the maximum total number of containers on the container ship; the other is the relationship between fuel and sailing distance. It is necessary to ensure that the sailing fuel can reach the next port of call that can load methanol tank containers, which is expressed by formula (VII).

[0092]

[0093] In formula (VI), δ is a port among A, B, ..., X, Y, Z; N 货δ is the number of cargo containers at port δ; N 罐δ is the number of methanol tank containers in δ port; N 总 The maximum total number of containers on a container ship.

[0094] In formula (VII): N * is a port from A to Z where methanol fuel can be refueled or methanol tank containers can be loaded, and γ is A, B, C…N * -1 port; α=A, B…X, Y, Z represent different ports; K α M is the loading rate of the fuel tank at port α, which is the percentage of methanol fuel added to the fuel tank at port α to the total capacity of the fuel tank; 舱 M is the capacity of methanol fuel in the fuel tank. When a methanol container ship sails on a certain route, the capacity of its fuel tank is fixed. 舱 is a fixed value; The refueling coefficient refers to whether the port has the conditions for refueling methanol fuel. No refill conditions M 罐 is the capacity of methanol fuel in the tank. The capacity of the methanol tank is fixed, so M 罐 is a fixed value; N 罐γ is the number of methanol tanks in port γ; μ is the richness coefficient of methanol fuel, which is generally 1.1-1.2; λ is the average daily consumption of methanol fuel; V 平 is the average speed; S A,γ+1 It is the distance from the departure port A to a port where methanol fuel can be refueled or methanol tank containers can be loaded.

[0095] The departure port of the container ship is Port A, and it passes through Ports B, C, ... X, Y, and Z. During the voyage, the ship fills the fuel tank with methanol or loads methanol tank containers at some of the ports. Based on the different fuel prices at the ports and the quantity relationship between methanol tank containers and cargo containers, in order to minimize the cost of refueling, the methanol fuel cost is calculated according to Formulas (I), (II), and (III) based on the actual situation and on the premise of Formulas (VI) and (VII).

[0096] The departure port of the container ship is Port A, passing through Ports B, C, ... X, Y, and Z. In this process, the cargo can be transported from one port to other ports according to different needs. Considering that the fuel of the ship in Formula (VII) can reach the next port of call that can load methanol tank containers, a certain number of methanol tank containers are already loaded on the ship. It is necessary to coordinate the quantity relationship between methanol tank containers and cargo containers so that the cargo container freight carried can obtain the maximum profit. Under the premise of Formula (VI) and Formula (VII), the cargo container freight is calculated according to Formula (IV).

[0097] In order to better understand the above method of calculating the total cost (V), let's take Port A as the departure port and Ports B, C, and D as the transit ports as an example. Figure 5As shown in the figure. Port B does not have the conditions for loading and filling methanol fuel and hoisting methanol tank containers, while Ports A, C, and D can load methanol fuel and hoist methanol tank containers. The transportation between various cargo containers is as follows Figure 6 , Figure 7 , Figure 8 As shown, the following situations are analyzed:

[0098] Case 1: The quantitative relationship formula (VI) between cargo containers and methanol tank containers is met. There is sufficient space for the containers and the methanol in the fuel tank can support the entire voyage. There is no need to refill the fuel tank with methanol fuel at the intermediate port, and there is no need for methanol tank containers to serve as "mobile fuel tanks" for container ships.

[0099] If the methanol price at Port A is lower than that at Ports C and D, then the fuel tank only needs to be filled at Port A. Figure 6 As shown, the load is normally carried out according to the demand. According to formula (V), we can get:

[0100] C 总 =N 1C P 1C +N 1D P 1D +N 2D P 2D +N 3D P 3D -M 舱 P 燃A

[0101] If the price of methanol at Port C is lower than that at Ports A and D, the fuel tank will be loaded with a portion of methanol at Port A to reach Port C. After arriving at Port C, the fuel tank will be filled with methanol fuel at Port C. Since Port C is a refueling port, Cargo box according to Figure 6 As shown, the load is normally carried out according to the demand. According to formula (V), it can be obtained that:

[0102] C 总 =N 1C P 1C +N 1D P 1D +N 2D P 2D +N 3D P 3D -M 舱 P 燃A -K C M 舱 P 燃C

[0103] Case 2: The quantitative relationship formula (VI) between cargo containers and methanol tank containers is satisfied. There is sufficient space for cargo containers but the fuel in the fuel tank cannot support the entire voyage. In this case, methanol tank containers are needed as the "mobile fuel tank" of the container ship. The lifting of methanol tank containers is more convenient than filling the fuel tank. Due to sufficient space for cargo containers, methanol tank containers are mainly used as fuel.

[0104] If the methanol price at the departure port A is the lowest, then all methanol will be loaded from A. Figure 6 As shown, the load is normally carried out according to the demand. According to formula (V):

[0105] C 总 =N 1C P 1C +N 1D P 1D +N 2D P 2D +N 3D P 3D -M 舱 P 燃A -N 罐A M 罐 P 燃A

[0106] If the methanol price at the intermediate port C is the lowest, then no matter what the methanol prices at ports A and D are, the methanol loaded from port A must reach port C. For the trip after port C, the methanol needed can be filled at port C. Figure 6 As shown, the load is normally carried out according to the demand. According to formula (V):

[0107] C 总 =N 1C P 1C +N 1D P 1D +N 2D P 2D +N 3D P 3D -M 舱 P 燃A -N 罐A M 罐 P 燃A -N 罐C M 罐 P 燃C

[0108] If the methanol price at port D is the lowest, the methanol price at port A is relatively low, and the methanol price at port C is the highest, then the methanol loaded at port A can reach port D, and the required methanol can be filled at port D in the subsequent trip. Figure 6 As shown, the load is normally carried out according to the demand. According to formula (V):

[0109] C 总 =N1C P 1C +N 1D P 1D +N 2D P 2D +N 3D P 3D -M 舱 P 燃A -N 罐A M 罐 P 燃A -N 罐D M 罐 P 燃D

[0110] If the methanol price at port D is the lowest, the methanol price at port A is the highest, and the methanol price at port C is the lowest, then the methanol loaded at port A can reach port C, and then the methanol loaded at port C can reach port D, and the methanol needed later can be filled at port D. Figure 6 As shown, the load is normally carried out according to the demand. According to formula (V):

[0111] C 总 =N 1C P 1C +N 1D P 1D +N 2D P 2D +N 3D P 3D -M 舱 P 燃A -N 罐A M 罐 P 燃A -N 罐C M 罐 P 燃C

[0112] -N 罐D M 罐 P 燃D

[0113] Case 3: The quantitative relationship formula (VI) between cargo containers and methanol tank containers is not satisfied. The number of container ship slots is insufficient. The methanol fuel fills the fuel tank at the departure port, and the fuel tank needs to be replenished at the intermediate port. The container ship can sail the entire journey with all the slots filled with cargo containers. Methanol is refueled at the departure port A, and the fuel tank is refueled at the refueling ports C and D at any time. Since C and D are refueling ports, then Cargo box according to Figure 6 As shown, the load is normally carried out according to the demand. According to formula (V):

[0114] C 总 =N 1C P 1C +N 1D P1D +N 2D P 2D +N 3D P 3D -M 舱 P 燃A -K C M 舱 P 燃C -K D M 舱 P 燃D

[0115] Case 4: The quantitative relationship formula (VI) between cargo containers and methanol tank containers is not satisfied. The number of container ship slots is insufficient. If the methanol in the fuel tank cannot be transported to the next refueling port, the methanol tank container can be used as the "mobile fuel tank" of the container ship to ensure that the container ship can reach the next refueling port. If the remaining slots after loading the methanol tank container cannot accommodate all cargo containers, a batch of low-profit cargo can be discarded according to the actual situation. Figure 7 As shown in the figure, the freight rates of containers are compared and selected, such as Figure 7 As shown in (a), both Cargo 1 and Cargo 4 have a batch shipped to Port C. At this time, the batch with the lowest profit should be discarded. If Cargo 4 has a lower profit than Cargo 1, then the batch of Cargo 4 shipped from Port A to Port C should be discarded. Figure 7 As shown in (b), the container freight can be obtained according to formula (IV): C 运 =N 1C P 1C +N 1D P 1D +N 4B P 4B +N 3D P 3D .

[0116] If the methanol price at the departure port A is the lowest and the methanol price at the departure port C is higher, due to insufficient container space, Figure 7 (b) The freed-up container space can be divided into two parts. The first part is to load methanol tank containers so that the container ship can reach the next refueling port, Port C. The second part of the container space can be used to compare the price of loading methanol at Port A with the price of loading container freight at Port A.

[0117] (1) If the cost savings from loading methanol at Port A is higher than the freight earned from loading at Port A, the second portion of the container space will be used to load methanol at Port A. The relationship between the cargo space and the container space is as follows: Figure 7 As shown in (b), according to formula (V):

[0118] C 总 =N 1C P 1C +N 1D P 1D +N 4B P 4B +N3D P 3D -M 舱 P 燃A -N 罐A M 罐 P 燃A

[0119] (2) If the cost savings of loading methanol at Port A is lower than the freight cost of loading at Port A, the second part of the container space will be loaded at Port A and shipped to Port B. Figure 8 As shown in the figure, the cargo container space of cargo 5 unloaded at Port B can be vacated to load methanol tank containers at Port C. According to formula (V):

[0120] C 总 =N 1C P 1C +N 1D P 1D +N 3D P 3D +N 4B P 4B +N 5B P 5B -M 舱 P 燃A -N 罐A M 罐 P 燃A -K C M 舱 P 燃C -N 罐C M 罐 P 燃C

[0121] If the methanol price at Port C is the lowest and the methanol price at Port A is higher, due to insufficient container space, Figure 7 (b) The freed-up container space can be divided into two parts. The first part is to load methanol tank containers so that the container ship can reach the next refueling port, Port C. The second part of the container space is to load some cargo containers at Port A. The relationship between the cargo containers is as follows: Figure 8 As shown. According to formula (V):

[0122] C 总 =N 1C P 1C +N 1D P 1D +N 3D P 3D +N 4B P 4B +N 5B P 5B -M 舱 P 燃A -N 罐A M 罐 P 燃A

[0123] -K C M 舱 P 燃C -N 罐C M 罐 P 燃C

[0124] The charges for other ports are the same as those for Port A and Port C mentioned above.

[0125] The above method describes the calculation method of container freight and methanol fuel costs in a single trip of a container ship starting from Port A, passing through Ports B, C...Y, and finally arriving at Port Z; the calculation method of container freight and methanol fuel costs in the trip returning from Port Z, passing through Ports Y, X...B, and finally arriving at Port A is the same as above.

[0126] The price of methanol fuel is different in each port due to its own conditions. The freight rates of various types of cargo containers carried by container ships are different due to the different types of cargo containers and transportation distances. The present invention is based on two important variables, methanol fuel price and cargo container freight, and loads and unloads methanol tank containers and cargo containers at different ports. In the limited space of container ships, the method proposes four situations. The scientific loading of the quantity relationship between methanol tank containers and cargo containers is achieved through the method of the present invention, so as to maximize the revenue of the ship.

[0127] The above is only a preferred implementation mode of the present invention, but it is not limited to the above embodiments when it is implemented. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A large-scale methanol powered container ship tank fuel system, characterized in that: The system comprises a methanol tank (1), a fuel tank (2), a transfer pump (3), a booster pump (4), a heating unit (5), and a pipeline interface (8). The methanol tank (1) is connected to a pipeline via the pipeline interface (8), and is sequentially connected to the booster pump (4), the heating unit (5), and a power device via the pipeline; the transfer pump (3) is located in the fuel tank (2), and is sequentially connected to the booster pump (4), the heating unit (5), and the power device via the pipeline. The methanol tank container is used as a "mobile fuel tank" of the container ship, and the ship loads the methanol tank container at different ports of call.

2. A method for utilizing large methanol powered container ship tank fuel based on the system of claim 1, characterized in that: Total revenue of the ship C 总 Freight by container C 运 and methanol fuel cost C 燃 The difference between 总 =C 运 -C 燃 , Among them, α=A, B…X, Y, Z represent different ports, β=1, 2, 3…n represent different cargoes, N βα represents the number of containers of cargo β at port α, P βα It represents the container freight rate of cargo β at port α, Methanol fuel cost C 燃 Including methanol fuel cost in the fuel tank C 舱燃 and methanol fuel cost C in methanol tank 罐燃 , Among them, M 舱 is the capacity of methanol fuel in the fuel tank, M 舱 is a fixed value, P 燃A is the price of methanol fuel in port A, K α is the fuel tank loading rate at port α, P 燃α is the price of methanol fuel at the refueling port α, is the filling coefficient, Where N 罐α is the number of methanol tank containers loaded at port α, M 罐 is the capacity of methanol fuel in the methanol tank, M 罐 Is a fixed value.

3. The method of utilizing large-scale methanol powered container ship tank fuel according to claim 2, characterized in that: This method has two prerequisites. One is N 货δ +N 罐δ ≤N 总 , where δ is a port among A, B, ..., X, Y, Z, N 货δ is the number of cargo containers in port δ, N 罐δ is the number of methanol tanks in δ port, N 总 is the maximum number of containers on a container ship, Second, Where N * is a port from A to Z where methanol fuel can be refueled or methanol tank containers can be loaded, and γ is A, B, C…N * -1 port in a port, N 罐γ is the number of methanol tanks in port γ, μ is the richness coefficient of methanol fuel, λ is the average daily consumption of methanol fuel, V 平 is the average speed, S A,γ+1 It is the distance from the departure port A to a port where methanol fuel can be refueled or methanol tank containers can be loaded.

4. The method of using large methanol powered container ship tank fuel according to claim 2, characterized in that: Calculate the total revenue C of a container ship based on four practical situations during its voyage. 总 , Case 1: Satisfying N 货δ +N 罐δ ≤N 总 , if there is sufficient space and the methanol fuel in the fuel tank can sail the entire journey, then methanol tanks will not be loaded. According to the formula Calculate C 总 =C 运 -C 燃 , and the total revenue of the ship is obtained, Case 2: Satisfying N 货δ +N 罐δ ≤N 总 , the tank space is sufficient but the methanol fuel in the fuel tank cannot sail the entire journey. Methanol tanks are used to provide power for the ship. According to the formula Calculate C 总 =C 运 -C 燃 , and the total revenue of the ship is obtained, Case 3: Insufficient container space on the container ship, not meeting N 货δ +N 罐δ ≤N 总 When the methanol in the fuel tank can support the entire voyage and all the cargo spaces are loaded with cargo containers, the fuel tank will be replenished with methanol at the intermediate port. Calculated according to the formula Calculate C 总 =C 运 -C 燃 , and the total revenue of the ship is obtained, Case 4: Insufficient container space on the container ship, not meeting N 货δ +N 罐δ ≤N 总 When the methanol in the fuel tank cannot reach the next refueling port, the ship is powered by methanol tank containers. After the methanol tank containers are loaded, the remaining space cannot accommodate all cargo containers. In this case, a batch of low-profit cargo containers are discarded. The methanol fuel price and cargo container freight are compared, and the relationship between the number of cargo containers and methanol tank containers in the remaining space is scientifically allocated. According to the formula Calculate C 总 =C 运 -C 燃 , and get the total ship revenue.

5. The method of utilizing large-scale methanol powered container ship tank fuel according to claim 2, characterized in that: The K α is the loading rate of the fuel tank at port α, which is the percentage of methanol fuel filled into the fuel tank at bunkering port α to the total capacity of the fuel tank.

6. The method of utilizing large-scale methanol powered container ship tank fuel according to claim 2, characterized in that: The refueling coefficient refers to whether the port has the conditions for refueling methanol fuel. No refill conditions 7. The method of using large methanol powered container ship tank fuel according to claim 2, characterized in that: If there are methanol tanks on board, the methanol in the tanks will be used first. After the methanol tanks are used up, the methanol in the fuel tank will be used to power the ship.

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