CN113343368A

CN113343368A - ARENA-based method for calculating influence of LNG ship entering port on channel passing capacity

Info

Publication number: CN113343368A
Application number: CN202110895402.2A
Authority: CN
Inventors: 李延伟; 张磊; 张玉倩; 陈巍博; 舒适; 孔宪卫; 干伟东; 赵维阳
Original assignee: Tianjin Research Institute for Water Transport Engineering MOT
Current assignee: Tianjin Research Institute for Water Transport Engineering MOT
Priority date: 2021-08-05
Filing date: 2021-08-05
Publication date: 2021-09-03

Abstract

The invention provides a method for calculating the influence of the ARENA-based LNG ship entering a port on the channel passing capacity, which comprises the following steps of: the method comprises the following steps of establishing a ship model of a ship arriving at a port corresponding to a channel to be analyzed; determining conventional navigation logic of the ship model navigation; after the LNG ship is added, correcting the conventional navigation logic to obtain a contrast navigation logic which meets the navigation requirement of the LNG ship; and respectively inputting the conventional navigation logic and the comparison navigation logic into ARENA for operation to obtain a prediction result. The influence of the LNG ship entering the port on the channel passing capacity is determined by comprehensively considering key factors such as the setting of the LNG ship moving safety area, the ship arrival rule, the tide characteristics, the influence of severe weather, the ship berthing operation time and the like, so that the calculation method provided by the invention can provide a simulation result more fitting the reality.

Description

ARENA-based method for calculating influence of LNG ship entering port on channel passing capacity

Technical Field

The invention relates to the technical field of simulation calculation of channel passing capacity, in particular to a method for calculating the influence of ARENA-based LNG ship entering a port on the channel passing capacity.

Background

Liquefied Natural Gas (LNG) is a high-quality, high-efficiency, clean, low-carbon energy source. The method has the advantages of cleanness, high efficiency and convenience, and has important strategic significance for adjusting the energy structure, promoting energy conservation and emission reduction and coping with climate change. The LNG industry is rapidly developed, and the LNG transportation amount and the ship flow are continuously increased. A plurality of LNG docks are respectively established in ports of Dalian, Caofen Dian, Tianjin, Dongjiakou, Yangtou, Yangshan, Ningbo, Pu, Zhuhai, Shenzhen, Yanpu and the like in China.

However, LNG is highly dangerous, so that potential hidden dangers are generated to port navigation safety during navigation of an LNG ship, once an accident occurs to the ship, light persons endanger the port and ship safety, the navigation order and the smooth navigation in port water areas are affected, heavy persons cause ship explosion and environmental pollution, and serious casualties, property loss and severe social influences are caused. In view of the high risk of LNG ship transportation, the navigation requirement of the LNG ship is correspondingly high, and the LNG ship has strong exclusivity. When an LNG ship is sailing in a channel, the maritime department usually takes strict traffic control measures for the channel, or takes a channel clearing mode, or sets up mobile safety. No matter which kind of traffic organization, all produce different degree influences to the navigation of other boats and ships in the harbor district for other boats and ships can't make full use of channel. Particularly, when the flow of the navigation ship at the port is large, the passing capacity of the channel is further influenced by the entrance and the exit of the LNG ship, and the accurate prediction calculation of the navigation capacity of the channel can be used for guiding the planning construction of the port area. The problem that the accuracy of a calculation result is relatively poor due to the fact that part of factors cannot be considered or a conversion coefficient is inaccurate when the current queuing theory method, the empirical formula method and the saturation method are used for calculating the passing capacity of the navigation channel.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a calculation method for the influence of the ARENA-based LNG ship entering a port on the channel passing capacity, and the calculation result of the method has higher precision and more guiding significance.

The technical problem to be solved by the invention is realized by adopting the following technical scheme:

a method for calculating the influence of ARENA-based LNG ship entering a port on the channel passing capacity comprises the following steps,

(1) establishing a ship model of the ship arriving at the port corresponding to the channel to be analyzed;

(2) determining conventional navigation logic of the ship model navigation;

(3) after the LNG ship is added, correcting the conventional navigation logic to obtain a contrast navigation logic which meets the navigation requirement of the LNG ship;

(4) inputting the conventional navigation logic and the comparison navigation logic into ARENA respectively for operation to obtain a prediction result;

the comparison navigation logic comprises a night navigation sub-logic, the night navigation sub-logic comprises a tonnage grade rule, an execution time rule and a night navigation rule, and the night navigation rule is executed when the LNG ship meets the tonnage grade rule and the execution time rule;

the tonnage grade rule is that a navigation limiting threshold value is set, and if the tonnage grade rule exceeds the navigation limiting threshold value, night navigation is not allowed; if the navigation limit threshold value is not exceeded, the night navigation is allowed;

the execution time rule is to navigate all day in summer and only navigate in the daytime in spring and autumn;

the night navigation rules are that the navigation speed of the LNG ship is reduced by 20% on the basis of the conventional entering port navigation speed, and the safety distance between the LNG ship and other ships is increased by 1 time or the channel is sealed.

In the invention, further, the correction factors for correcting the conventional navigation logic after the LNG ship is added are that the traffic priority of the LNG ship is set to be the highest priority and the navigation safety distance of the LNG ship is set to be the highest safety distance.

In the invention, further, the ship model comprises the number of ships arriving at port and ship attributes, the arrival time of the ships in the ship model obeys poisson distribution, and the ship attributes are configured for the ships in the ship model, wherein the ship attributes comprise the attribute parameters of cargo class, ton level, ship type, ship length, draught and speed.

In the invention, further, the conventional navigation logic comprises ship queuing waiting logic, ship navigation logic and ship operation logic, and the ship queuing waiting logic, the ship navigation logic and the ship operation logic need to be sequentially met during calculation;

the ship queuing waiting logic is that when the ship simultaneously meets a berthing model, an environment model and an entering and exiting port sequence, the ship enters a channel;

the ship navigation logic is to set a first-level safety distance of a common ship;

the vessel operation logic is configured to determine a berthing operation duration and a loading and unloading operation duration of the vessel.

In the invention, further, the ordinary ships in the ship model are divided into tide-riding ships and non-tide-riding ships, the tide-riding ships and the non-tide-riding ships are respectively preset, the priority of the tide-riding ships is set as a second priority, the priority of the non-tide-riding ships is set as a third priority, the priorities of the second priority and the third priority are sequentially decreased, and the port-entering and port-exiting sequence conforms to the setting sequence of the priorities.

In the present invention, further, the environment model includes a weather model and a tide level change model.

In the present invention, the weather model further includes a first weather model and a second weather model, the first weather model is used for setting the occurrence probability of the severe weather that the ordinary ship cannot go out of the ship according to the preset weather transportation information, and the second weather model is used for setting the occurrence probability of the severe weather that the LNG ship cannot go out of the ship according to the preset weather transportation information.

In the invention, further, the change rule of the tide level with time in the tide level change model is

H is the tide height at the time t; h_aveThe average half-tidal plane is also called hydrostatic plane; r is tidal range, is a variation value, and is randomly determined according to the cumulative frequency of tidal range; t is the tidal cycle;

the lowest sea level corresponding to the minimum safe water depth required by navigation of the vessel entering the port by the tide is called as the tide taking water level, and the calculation formula is

Wherein L is the draught of the ship; d is the designed water depth of the channel; delta D₁The surplus water depth is obtained; delta D₂Is the height difference between the water depth reference surface and the tide level reference surface of the channel.

In the invention, further, the average value of the historical operation time length is selected according to the leaving operation time length.

In the present invention, the loading and unloading operation duration further follows Erlang distribution, and the loading and unloading time of the LNG ship adopts fixed-length distribution according to the loading and unloading cargo quantity, wherein an Erlang distribution density function is:

in the formula: k is the order of the Erlang distribution,

and d, averaging the parking operation time by taking mu as a time parameter for parking operation time.

The invention has the advantages and positive effects that:

the influence of the LNG ship entering the port on the channel passing capacity is determined by comprehensively considering key factors such as the setting of an LNG ship moving safety area, the ship arrival rule, the tide characteristics, the severe weather influence, the ship berthing operation time and the like, and meanwhile, the key influence factor of night voyage operation is added in the method, so that the calculation method provided by the invention can provide a simulation result which is more practical, and further, the average waiting time of the ship, the average waiting number of the ship and the like can be quickly obtained by using the calculation method based on ARENA software, so that the logic and quantity relation of the actual operation and management rules in the port is effectively reflected, and the actual operation condition of the port is objectively reflected.

Drawings

Fig. 1 is a control flow diagram of a conventional navigation logic in the present invention.

Detailed Description

The embodiments of the invention will be described in further detail below with reference to the accompanying drawings:

the port system is a random service system with multiple random factors and complex dynamic association. In the system, due to the influence of random factors such as port arrival time of ships, berthing time on berths and the like, the operation of the channel is in a 'busy and idle uneven' state, which brings certain influence on the normal performance of the channel passing capacity. On the other hand, the phenomenon of channels such as easy occurrence of ships needing to enter and exit ports due to the limitation of self conditions and natural conditions of the channels can also increase the occupancy rate of berths and the waiting time of the ships at anchoring places, and the non-productive stop of the ships at the ports is prolonged, so that the passing capacity of the ports is influenced, and the huge waste of the transport capacity of the ships is caused. Furthermore, the calculation of the channel capacity is difficult and important in view of the increasing LNG traffic and ship traffic and the high risk of transportation.

The invention utilizes the Rockwell Arena simulation technology, establishes a logic and quantity relation model reflecting the actual operation and management rules in the port and applies the model to carry out relevant simulation experiments, can objectively reflect the actual operation condition of the port and carry out quantitative analysis on the passing capacity of the channel, thereby realizing the effect of accurately describing the influence of the dynamic change of the port ship navigation operation system on the passing capacity of the channel. Rockwell Arena simulation software is the prior art and is mainly used for simulating and calculating the traffic capacity of a port under limited navigation logic.

The channel capacity is the primary measure of the capacity of a channel to channel a ship. It is defined as the annual average or annual maximum navigable density (e.g., one/day) for a given channel at a given port in a given port area when the specified port service level is reached under normal port production operations. However, although the channel passing capacity in the general sense gives the traffic capacity of a certain channel under actual conditions, from the viewpoint of planning, management and service supply, this index alone is not sufficient because it cannot reflect the traffic state and service quality of the channel yet, and therefore, in the present invention, two indexes of the average waiting channel time of the ship and the average waiting channel number of the ship are used as the channel passing capacity influence evaluation criteria.

As shown in fig. 1, the method for calculating the influence of arana-based LNG ship entering port on the channel passing capacity of the ARENA-based LNG ship according to the present invention, using the channel passing capacity calculation of the tianjin port and the hong port area as an example, comprises the steps of,

establishing a simulation model system based on the characteristics of the harbor area channel system and the ship traffic flow characteristics;

the method comprises the steps of determining a calculation model of each factor influencing the channel passing capacity by collecting and sorting relevant basic data and data related to a Tianjin port and a big port area, and establishing a ship model of the port area to realize the construction of a simulation model system, wherein the construction specifically comprises the determination of conventional navigation logic. Conventional navigation logic is a common prior art for those skilled in the art, and is referred to in the paper of "high Cambridge. LNG ship navigation influence on channel passing capacity [ D ]. university of continental maritime, 2016", which mainly determines the navigation capacity of a port by determining specific parameters of multiple groups of influencing factors and inputting the parameters into simulation software.

Firstly, simulation software Arena generates ships arriving at a port according to a poisson distribution rule, the generated ships arriving at the port wait at an anchoring ground, the conditions that the ships enter a channel are verified from the aspects of berthing conditions, weather conditions and tide conditions, whether the conditions are met simultaneously is verified, if the conditions are met, the ships enter the channel, and if the conditions are not met, the ships continue to wait in a queue, whether LNG ships enter the channel is judged to control the safe distance of the ships entering the channel, the ships in the channel drive to the berth, berthing operation and berthing loading and unloading operation are sequentially carried out, and the ships enter the channel again to leave the port after the conditions of leaving the port are met. The operation process of the simulation software Arena is set and optimized according to the conventional navigation logic and the comparison navigation logic, so that the final simulation result is more accurate.

The specific method for comparing the navigation logics is obtained by correcting the conventional navigation logics after the LNG ship is added, and the specific correction factors are two, namely, the traffic priority of the LNG ship is set to be the highest priority and the navigation safety distance of the LNG ship is set to be the highest safety distance. Particularly, the LNG ship passes through all ships with the highest priority, and the safety distance is set to be 1 nautical mile or longer. The following is a specific determination of the conventional navigation logic and the comparative navigation logic.

The conventional navigation logic in this embodiment is as follows:

the ship generation module in the simulation software Arena generates ship models, namely ship models, of the arriving ships and LNG ships meeting the requirements, generates the arrival time of the ships according to the Poisson distribution rule, sets the cargo class, the tonnage, the ship shape, the ship length, the draft and the navigational speed of the ships, and records the arrival number of the ships and the arrival time of each ship so as to perform statistical output of data.

The arrival law of ships has a direct influence on port production. When the ships arrive at the port densely, port production is in a tense state, and the phenomena of equal berthing and equal channel of the ships can occur; when the ship arrives sparsely, the port production is in a slack state. The time interval of arrival of the ship at the port follows the rules of negative index distribution, poisson distribution, Erlang K-order distribution and the like, and the specific rules are related to the property of the wharf. In this embodiment, the arrival law of the ship is set to comply with the poisson distribution. In the embodiment, the arrival of the ship is determined as the entering condition determination link on the basis that the ship punctual point arrives at the designated berthing water area (such as an anchor ground). Specifically, the poisson distribution model is,

in the formula, P_nAnd (t) is a distribution function of time t, and lambda is the average ship arrival rate of the research section in the time period t, namely the number of ships arriving in unit time.

In simulation software Arena, a Create module and an Assign module are used for creating a ship generation module; generating a ship arriving at port in a Create module and setting the time for the ship to arrive at the port; and setting parameters of the ship to port in the Assign module, such as the properties of ship cargo, tonnage, length, width, draught, speed and the like.

In simulation software Arena, a ship berth-indicating module is used for realizing the establishment of a berth model, the module is used for appointing loading and unloading berths for a ship according to the cargo type and the tonnage of the coming ship, when no proper berthing operation exists or the sailing condition is not met, a berthing anchoring ground is appointed for the coming ship according to the cargo type and the tonnage of the ship,

it is supplementary to be added that the port anchor sites can be divided into the harbor outside anchor sites and harbor inside anchor sites according to the geographical location. The anchor land outside the port is used for tide waiting, mooring, joint inspection and wind avoidance of the ship; the anchoring ground in the harbor is used for the ship to be moored or for the loading and unloading operation on water. In this embodiment, the anchorage is the water area where a series of waiting processes are completed after the ship arrives at the port and before entering the channel. It should be noted that in this embodiment, the large port area has sufficient anchoring ground to provide the ship with the service of waiting for the channel and berth.

Specifically, the ship queuing and waiting logic is that ships arriving at a port of the same type and the same tonnage need to be parked at a designated berth, and can enter the port if the berth is free, and can enter the port if the berth is busy and needs to wait until the berth is free at an anchor place.

Then, in the conventional navigation logic, ordinary ships (the ordinary ships mentioned in the invention specifically refer to other ships except for LNG ships) in the ship model are divided into the tide-taking ships and the non-tide-taking ships, the tide-taking ships and the non-tide-taking ships are respectively preset, the priority of the tide-taking ships is set as a second priority, the priority of the non-tide-taking ships is set as a third priority, the priorities of the second priority and the third priority are sequentially decreased, and the port-entering and port-exiting sequence conforms to the setting sequence of the priorities. Usually, a large ship needs to wait for a tide level, take a tide and enter and exit a port;

most of the port's large vessels need to take the tide in and out of the port, which becomes an important factor affecting the voyage, limited by the natural conditions of the port or in order to reduce the dredging costs. According to the regulations of the general design code of harbours and the design code of liquefied natural gas terminals, in the embodiment, the tide factor is considered only for other large ships, and the LNG ship does not need to take the tide.

The tide level in the tide level change model changes along with time, a sine curve is adopted to fit the change of the tide level, the change rule of the tide level along with time is as follows,

h is the tide height at the time t; h_aveThe average half-tidal plane is also called hydrostatic plane; r is tidal range, is a variation value, and is randomly determined according to the cumulative frequency of tidal range; t is the tidal cycle.

When the natural water depth can not meet the harbor entrance requirement of the ship (except for the LNG ship), the ship needs to take the tide to enter the harbor. The lowest sea level corresponding to the minimum safe water depth required by navigation of the vessel entering the port by the tide is called as the tide taking water level, and the calculation formula is

Wherein L is the draught of the ship; d is the channel design water depth; delta D₁The surplus water depth is obtained; delta D₂Is the height difference between the water depth reference surface and the tide level reference surface of the channel.

Limiting the entry and exit of the ship under severe weather conditions; the weather model comprises a first weather model and a second weather model, the first weather model is used for determining the weather model more specifically and accurately according to preset weather communication information, the weather communication information specifically comprises weather information of nearly 3-5 years and related file information of all ship safety navigation standards, and the second weather model is used for setting the occurrence probability of the severe weather that the LNG ship cannot navigate according to the preset weather communication information.

In the weather model, port weather characteristics are statistically analyzed according to historical data, ship navigation characteristic requirements, particularly LNG ship operation conditions are considered, the number of days of influence of wind, waves, flow and fog on a port is calculated and reduced, and the probability of occurrence of severe weather is determined. Specifically, the weather model is established as follows:

in the formula:

the sum of the severe weather influence days after the reduction calculation; p₁Probability of occurrence in bad weather; p₂Is the normal weather occurrence probability. The first weather model and the second weather model are both the weather models, and only two different weather limiting results can be obtained due to different limiting conditions of the ordinary ship and the LNG ship.

In the conventional operation regulation, the LNG ship is not suitable for entering and exiting port and berthing at night, after the ship arrives at a specified berthing place, the arrival time is judged firstly, if the ship arrives at the specified berthing place, the LNG ship selectively enters the port and berths, and the selectivity is that the ship can enter the port and berth when the ship meets the following limiting conditions for the night navigation ship; if the navigation is in the daytime, the navigation is directly carried out in the port;

however, the invention increases the simulation factor for the night voyage of the LNG ship, so that the accuracy of the simulation result can be further improved, and the specific conditions (i.e. night voyage sub-logic) for the night voyage ship are limited as follows:

1. defining a partial LNG ship profile allows night sailing (specifically 17.7 km in this example)³The ship type allows the following. Judging the size of the LNG ship by adding a module, if the LNG arrives at 17.7 ten thousand meters³Below, the harbor can be reached at night, if it is more than 17.7 ten thousand m³Then, only can enter the port in the daytime);

2. the method comprises the steps of limiting the navigational speed of the LNG ship at night, and reducing the navigational speed by 20% on the basis of the normal navigational speed (for example, the navigational speed in the daytime is 10kn, the navigational speed in the night is 8kn, and the navigational speed in the daytime is 8kn, and the navigational speed in the night is 6 kn);

and 3, when the LNG ship sails at night, the original mobile safety area is adjusted to be closed, namely when the LNG ship sails at night, other ships are not allowed to navigate in the channel (or when the LNG ship is adjusted to be sailed, the safety distance between the LNG ship and other ships is properly increased by 1 time).

In actual operation, sunrise and sunset are generally used as the demarcation point of day and night. However, sunrise and sunset times of different regions and each day in one year are different, through analysis of the navigation condition of a large-port navigation channel in recent years, the navigation time of the navigation channel is mainly influenced by meteorological environments such as strong wind, strong ice, heavy fog, heavy waves and the like, the number of normal navigation days per year is 330 days, and the number of non-navigation days per year of the navigation channel is 35 days. Because the current large port waterway is only limited to sailing by ships in the daytime, the current large port waterway is 06: 30-18: 30 in summer, namely the navigation time is 12 hours each day; the effective navigation time per day of the large port navigation channel under the conventional navigation logic is 11 hours.

However, because the demand of LNG in actual production is very large, the effective navigation time of the channel every day needs to be corrected by the night navigation sub-logic in the current harbor district, specifically, the effective navigation time is adjusted from 11h to 15h (originally, the whole year of daytime navigation, the current adjustment is that the channel can be navigated in summer in one year, and the channel can be navigated only in the daytime in spring and autumn); and evenly distributing the navigation incapability days to one year, and setting the simulation model system to stop running for 11 hours every 120 hours.

The ship speed and the fixed safe interval in the system under the conventional navigation logic are set as follows:

(1) calculating the ship speed according to the average speed;

the length of the channel directly influences the channel navigation time of the ship, and the navigation time of different ships in the channel can be calculated according to the actual length of the channel and the navigation speed in the channel of the ship.

In this embodiment, the length of the channel in the large port area of the Tianjin port is 46km, and the average speed of each ship can be calculated according to the time of the AIS ship entering and leaving track in the large port area, wherein the average speed of the LNG ship is considered according to 8kn, and the average speed of the non-LNG ship is considered according to 10 kn.

(2) The ship keeps a certain safety distance in the channel to avoid collision accidents; the safe interval refers to the minimum interval for safe running of the ship, and the sailing speed of the ship in the channel is required to be controlled within a certain range.

The safe distance between the ships is generally expressed in the field of the ships, and is an ellipse with a long semi-axis along the direction of a bow line and a tail line and a short semi-axis along the positive transverse direction of the ship by taking the ship (an evaded ship) as a center. In general, the dimension of a region where a ship is tracked while the ship is underway is an ellipse formed by 8L and 3.2L (L is the length of the ship). If the ship is sailing in a port or in narrow waters where speed limits are required, the dimensions of the ship field are reduced to an ellipse made of 6L and 1.6L. In this embodiment, the safe distance before and after the non-LNG ship enters and exits the port is 6L.

(3) For the purposes of safety and environmental protection, a certain range of water area is arranged around the LNG ship, and the LNG ship and other ships are not allowed to enter the water area. According to the general design code of seaport, and referring to the actual practice of ports such as Tianjin port, in the embodiment, it is specified that the traffic control is performed half an hour before the LNG ship arrives at the port.

In simulation software Arena, a Decide module is used for judging whether an LNG ship enters a channel or not, and a Process module is used for realizing control over safety intervals of other ships by delaying ship entity entering time.

The ship operation logic is used for stipulating rules of ship berthing operation, loading and unloading operation at a berth and various auxiliary operations, and specifically comprises the following steps:

(1) the ship berthing and departing time is related to the refreshing degree of a berth harbor basin, the operating technology of a crew and natural weather, and is influenced by auxiliary operations, including start preparation, joint inspection, commodity inspection and ending, and the operation time is the average value of the actual multiple berthing operation time;

(2) the berth loading and unloading operation time is influenced by ship cargo loading amount, cargo type, loading and unloading equipment efficiency and management level factors, and comprises loading and unloading arm inerting, loading and unloading arm condensing and unloading procedures, the berthing operation time of the ship is a random variable and obeys Erlang distribution, and the LNG ship loading and unloading time is distributed in a fixed length according to the cargo loading and unloading amount. Wherein the Erlang distribution density function is:

in the formula: k is Erlang distribution order, mu is time parameter, and average berth operation time is taken.

In the simulation software Arena, the Delay module is used to represent the operation time of the ship, and the time required by the above-mentioned berthing operation and loading and unloading operation is uniformly covered.

The comparison navigation logic is just the result of correcting the conventional navigation logic after the LNG ship is added, and the specific correction factors of the correction are that the traffic priority of the LNG ship is set as the highest priority and the navigation safety distance of the LNG ship is set as the highest safety distance. The concrete expression is as follows:

the conventional ship enters and exits the port according to the principle of first-come first-serve, LNG ship first-serve and tide ship second-time. When the ships with relatively high priority degrees meet the port entering and exiting conditions, the ships are preferentially arranged to enter and exit, and when the priority degrees of the ships meeting the port entering and exiting conditions are equal, the ships which arrive first are served. That is, the traffic priority of the LNG ship is set to the highest priority, the priority of the tide ship is set to the second priority, the priority of the non-tide ship is set to the third priority, and the priorities of the highest priority, the second priority and the third priority are sequentially decreased.

The safe navigation distance of the LNG ship is the highest safe distance, specifically, when the LNG ship enters a channel, a moving safe area before and after the LNG ship is controlled or other ships are prohibited from entering the water area, and the safe area is set to be 1 sea or longer, and needs to be determined according to specific port conditions.

In the embodiment, the operation simulation model system simulates the process of the ship entering and exiting the port to navigate in the large port area in 1 year in different construction periods, the total operation time is 4000h, the operation is repeated for 10 times, and the influence degree of the LNG ship entering and exiting the port on the large port navigation channel passing capacity in different construction periods (different ship flow rates) is analyzed by adopting an average value.

Specifically, the LNG berth and the entering LNG ship in the large harbor area are respectively defined according to actual requirements and historical data, so that the influence degree of the entering and leaving of the LNG ship on the large harbor passage capacity under different ship flow rates is analyzed. Setting the large harbor area channel as one-way navigation, wherein each time of entering and exiting navigation is 6h, when the LNG berths of the large harbor area are defined to be 0, no LNG ship enters the harbor (the state is the navigation capability of the simulated channel where no LNG ship is), when the LNG berths of the large harbor area are defined to be 1, the annual harbor entry amount of the LNG ship is 95, when the LNG berths of the large harbor area are defined to be 2, the annual harbor entry amount of the LNG ship is 164, and under the three conditions, the annual harbor entry amounts of other ships are defined to be 2831, and the following table 1 is a simulation result of calculating the average waiting channel time of other ships and the average waiting channel number of other ships:

TABLE 1

Based on the simulation result, the method has more accurate guiding significance for optimizing navigation management rules of the large harbor district and planning construction of the harbor district, and can assist the construction and development of the harbor district.

It should be emphasized that the embodiments described herein are illustrative rather than restrictive, and thus the present invention is not limited to the embodiments described in the detailed description, and that other embodiments derived from the teachings of the present invention by those skilled in the art are also within the scope of the present invention.

Claims

1. A method for calculating the influence of ARENA-based LNG ship entering a port on the channel passing capacity is characterized by comprising the following steps: comprises the following steps of (a) carrying out,

step one, establishing a ship model of a ship arriving at a port corresponding to a channel to be analyzed;

determining the conventional navigation logic of the ship model navigation;

step three, after the LNG ship is added, correcting the conventional navigation logic to obtain a contrast navigation logic which meets the navigation requirement of the LNG ship;

step four, inputting the conventional navigation logic and the comparison navigation logic into ARENA respectively for operation to obtain a prediction result;

2. The method of claim 1 for calculating the effect of ARENA based LNG ship's inbound capacity on channel capacity, characterized by: and after the LNG ship is added, correcting factors for correcting the conventional navigation logic are that the passing priority of the LNG ship is set as the highest priority and the navigation safety distance of the LNG ship is set as the highest safety distance.

3. The method of claim 2 for calculating the effect of ARENA based LNG ship's inbound capacity on channel capacity, characterized by: the ship model in the first establishing step comprises the number of ships arriving at port and ship attributes, the arrival time of the ships in the ship model obeys poisson distribution, the ship attributes are configured for the ships in the ship model, and the ship attributes comprise the attribute parameters of cargo class, ton level, ship type, ship length, draft and speed.

4. The method of claim 3 for calculating the effect of ARENA based LNG ship's inbound navigation capacity on channel capacity, characterized by:

determining that the conventional navigation logic of the ship model navigation in the step two comprises ship queuing waiting logic, ship navigation logic and ship operation logic, and sequentially meeting the ship queuing waiting logic, the ship navigation logic and the ship operation logic when calculating;

5. The method of claim 4 for calculating the effect of ARENA based LNG ship's inbound port on channel capacity, wherein: dividing common ships in the ship model into tide-riding ships and non-tide-riding ships, respectively presetting the tide-riding ships and the non-tide-riding ships, setting the priority of the tide-riding ships as a second priority, setting the priority of the non-tide-riding ships as a third priority, and sequentially decreasing the priorities of the second priority and the third priority, wherein the port-entering and port-exiting sequence conforms to the setting sequence of the priorities.

6. The method of claim 4 for calculating the effect of ARENA based LNG ship's inbound port on channel capacity, wherein: the environment model comprises a weather model and a tide level change model.

7. The method of claim 6 for calculating the effect of ARENA based LNG ship's inbound capacity on channel capacity, characterized by: the weather model comprises a first weather model and a second weather model, the first weather model is used for setting the occurrence probability of the severe weather that the common ship cannot sail according to preset weather traffic information, and the second weather model is used for setting the occurrence probability of the severe weather that the LNG ship cannot sail according to the preset weather traffic information.

8. The method of claim 6 for calculating the effect of ARENA based LNG ship's inbound capacity on channel capacity, characterized by: the change rule of the tide level along with time in the tide level change model is

Wherein L is the draught of the ship; d is the designed water depth of the channel; delta D₁The surplus water depth is obtained; delta D₂Is channel waterThe difference between the height of the deep reference level and the height of the tidal level reference level.

9. The method of claim 4 for calculating the effect of ARENA based LNG ship's inbound port on channel capacity, wherein: and selecting an average value of historical operation time length by the berthing operation time length.

10. The method of claim 9 for calculating the effect of ARENA based LNG ship's inbound capacity on channel capacity, characterized by: the loading and unloading operation duration obeys Erlang distribution, the loading and unloading time of the LNG ship adopts fixed-length distribution according to the loading and unloading cargo quantity, wherein an Erlang distribution density function is as follows:

in the formula: k is the order of the Erlang distribution,