A method for improving the transit loading rate of a ship by dynamic draft control

Abstract

A method for improving the vessel loading rate through dynamic draft control includes the following steps: establishing a dynamic draft control model for the lock based on the relationship between water level and flow rate, lock operating conditions, vessel passage scheduling rules, and constraints on vessel draft control requirements; collecting the planned discharge flow from the lock's downstream channel and inputting it into the dynamic draft control model to calculate the downstream channel depth variation process; collecting vessel passage declaration information and determining the vessel passage plan based on the downstream channel depth variation process and lock operation plan compilation rules. This invention establishes a dynamic draft control model for the lock, scientifically grasps the channel depth variation pattern, and, while ensuring navigation safety, reasonably improves the vessel loading rate, further enhancing the lock's throughput capacity.

Description

Technical Field

[0001] This invention relates to the field of navigation scheduling technology, specifically to a method for improving the loading rate of ships passing through locks through dynamic draft control. Background Technology

[0002] Large-scale water conservancy projects are complex hydraulic structures built in suitable sections of rivers to meet the goals of various water conservancy projects. They generally consist of an upstream reservoir, the main project, and hydropower stations, locks, and other components distributed within the main project. Their main function is flood control, while also accommodating navigation and power generation while ensuring the effective functioning of flood control.

[0003] Hydropower stations play a crucial role in peak shaving and frequency regulation within the power grid. Consequently, the daily variation in discharge flow is typically significant during the daily operation of the hydropower station, especially during the dry season. Large-scale hydropower stations generally have more regular daily regulation patterns, and their power generation discharge flow plans are usually determined in advance. For locks whose downstream approach channels are water depth control sections in the dry season area, to ensure operational safety, the maximum controlled draft of vessels passing through the lock is generally determined based on the minimum daily discharge flow of the hydropower station. However, during periods of high discharge flow, the water depth of the lock's approach channel is not effectively utilized, and the navigation benefits of the lock are not fully realized. Summary of the Invention

[0004] This invention provides a method for improving the loading rate of ships passing through locks through dynamic draft control. This method establishes a dynamic draft control model for locks, scientifically grasps the variation law of water depth in the channel, and reasonably increases the loading rate of ships while ensuring navigation safety, thereby further improving the throughput capacity of locks.

[0005] The technical solution adopted in this invention is as follows:

[0006] A method for improving the loading rate of ships through locks by dynamic draft control includes the following steps:

[0007] Step 1: Based on the water level-flow relationship, lock operation conditions, ship passage scheduling rules, and ship draft control requirements, establish a dynamic draft control model for the lock.

[0008] Step 2: Collect the planned discharge flow of the hub, input it into the dynamic draft control model of the lock, and calculate the process of water depth change in the downstream channel of the lock;

[0009] Step 3: Collect vessel lock passage declaration information, and determine the vessel lock passage plan based on the water depth change process of the downstream channel of the lock in Step 2 and the lock operation plan preparation rules.

[0010] It also includes step 4: organizing ships to pass through the lock according to the ship passage plan determined in step 3, monitoring the water depth of the downstream channel in real time during the implementation process, and dynamically adjusting the ship passage plan according to the changes in channel water depth and flow.

[0011] In step 1, the method for establishing the water level-flow rate relationship is as follows:

[0012] Water level and flow rate observation samples were collected at the downstream channel control section of the lock. The downstream flow rate interval requiring dynamic draft control was defined as [Q1, Q2]. At regular intervals, i representative flow rates Q1 and Q2 were selected from the flow rate interval between Q1 and Q2. i Q i ∈[Q1,Q2], the downstream channel control section of the lock represents the flow set Q. i = (Q1, Q2, Q3, ... Q i Each representative flow corresponds to n. i Water level Z ni Then the corresponding value represents the flow rate Q. i Water level sample set Z ni =(Z i1 Z i2 Z i3 ...Z ini );

[0013] Take the representative flow Q i The corresponding water level sample set Z ni Based on the hydrological frequency calculation method and the channel depth guarantee rate P, Q is calculated. i The corresponding water level is Z. i According to Q i With Z i Based on the continuity of water level and flow rate changes, a function relating water level Z and flow rate Q at the downstream channel control section of the lock is fitted:

[0014] Z=f(Q) , Q∈[Q1,Q2] (1);

[0015] In equation (1), f(Q) is the functional relationship between the water level Z at the control section of the downstream channel of the lock and the discharge flow Q of the hub where the lock is located. This functional relationship needs to be obtained by combining the specific hydraulic conditions of the river channel where the lock is located, through sample collection, hydrological frequency calculation, and finally fitting.

[0016] In step 1, the lock operation conditions include determining the water depth h1 of the lower lock sill and the water depth h2 of the downstream channel control section, then:

[0017] h1 = Z - Z1 (2);

[0018] h2 = Z - Z2 (3);

[0019] Where: Z1 is the elevation of the lower lock head threshold; Z2 is the maintenance elevation of the downstream channel control section of the lock.

[0020] In step 1, the ship lock passage scheduling rules refer to the rules for the order of ship passage through the lock and the rules for organizing the ships to move from a more distant waiting anchorage to a closer departure waiting anchorage upstream or downstream of the lock based on the order of their passage through the lock.

[0021] In step 1, the ship draft control requirements include determining the allowable water depth Δh to ensure safe navigation of the ship. For ships passing through locks, this means:

[0022] Δh=δ1+δ2+δ3 (4)

[0023] Among them, δ1 is the amount of sinking during ship navigation; δ2 is the amount of allowance for ships not to touch the bottom, which is generally determined based on the navigation standards, waterway grade, riverbed bottom quality, and water depth fluctuation during lock discharge; δ3 is the allowance for water level fluctuation in the waterway, which is based on the trend of the discharge flow of the hub and the empirical value of the ship's departure and arrival cycle through the lock.

[0024] According to the method for calculating the sinking of a ship during navigation, the expression for δ1 is:

[0025] δ1=(-15.26x 2 +3.923x+0.267)×H (5);

[0026] For vessels passing through the lock, the variable x is calculated as follows:

[0027]

[0028] Where v is the ship's speed, taken as the maximum speed limit for ships passing through the lock; g is the acceleration due to gravity, which is 9.8 m / s². 2 H is the water depth h1 at the lower sill of the lock; S is the underwater cross-sectional area of ​​the lock chamber, so S = dh1; d is the width of the lock chamber; s is the underwater cross-sectional area of ​​the vessel passing through the lock. Let the maximum width of the vessel passing through the lock be d1 and the maximum draft of the lock be h3, so we can take s = d1h3.

[0029] In step 2, the planned discharge flow information of the hydropower station refers to the discharge flow of the hydropower station during the specific implementation period of the currently compiled ship passage plan. Hydropower stations with associated ship locks are large-scale water conservancy projects, and their main facilities generally include hydropower stations. The power generation plan for these hydropower stations is formulated in advance. During the dry season, the flow required for power generation by the hydropower station corresponds to the discharge flow of the hydropower station. Once the power generation plan is determined, the discharge flow of the hydropower station within the planned period is determined accordingly.

[0030] In step 2, the process of water depth change in the downstream channel of the lock is as follows:

[0031] Based on the planned discharge flow of the hydropower station and the water level-discharge relationship function of the downstream channel control section, the process curve of water depth variation in the downstream channel of the lock was calculated. The hydropower station where the lock is located generally has 1-2 peak power generation periods per day. During the peak power generation period, the discharge flow process curve of the hydropower station exhibits peak-shaped fluctuations. When power generation is low, the corresponding discharge flow is low, and when power generation is maximum, the corresponding discharge flow is at the peak.

[0032] In step 3, the rules for compiling the lock operation plan are as follows:

[0033] 1) Based on the lock operation status, calculate the number of lock operations (M) and the number of vessels passing through the lock during the current planned vessel passage period. The number of lock operations (M) and the number of vessels passing through the lock (N) include the number of upstream lock operations (M). s Number of ships going uphill N s and the number of down-going gates M x Number of ships going downhill N x ;

[0034] The lock operation status specifically refers to the routine planned maintenance and closure of lock-related equipment and facilities, as well as other closure situations. The closure duration is determined, and the lock's navigable duration during the current planned vessel passage period is calculated. This allows for the estimation of the number of lock operations (M) and the number of vessels (N) that can pass through the lock during the planned implementation period.

[0035] 2) Based on the current lockage schedule execution status, calculate the start time for each lockage session in the current vessel passage plan;

[0036] The start time of each lock in the current ship passage plan is as follows: Based on the current lock plan execution progress and the average lock duration, the start time of each lock in the current ship passage plan can be calculated, specifically the time when the ship releases its mooring line from the berthing pier and heads towards the lock gate.

[0037] 3) Based on the requirements for ship draft control, the order of ship passage through the lock, and the principle of maximizing the utilization rate of the lock chamber area, determine the ships passing through the lock and the order of ship passage through the lock.

[0038] The ship's draft control requirements are as follows:

[0039] ① For upstream vessels, when the lock operation begins at time t 上 According to the lock operation process, the opening and closing time of the downstream gate is approximately t. 上4 Let the average interval between lock operations be T1, and the average departure and arrival time of ships be T2. According to the ship passage scheduling rules, to ensure the efficient and orderly operation of the lock, the time for a ship to arrive at the berth is approximately t. 上3 Then we have:

[0040] t 上3 =t 上-T1 (7);

[0041] The ship's departure time is approximately t 上1 Then we have:

[0042] t 上1 =t 上3 -T2 = t 上 -T1-T2 (8);

[0043] Let L be the distance from the downstream channel control section of the lock to the lock's pier, and V be the average speed of the vessel in the channel. 平 The ship arrives at the downstream channel control section of the lock at t. 上2 Then we have:

[0044] t 上2 = t 上3 -L / V 平 = t 上 -T1-L / V 平 (9);

[0045] Based on the process of water depth change in the downstream channel of the lock generated in step 2, and equations (2) and (3), t is calculated. 上2 Water depth h at the downstream channel control section of the ship lock 上2 and t 上4 The water depth at the sill of the lower lock head is h. 上1 The maximum vessel draft control standard for this lock operation is determined to be h. 上 Then we have:

[0046] h 上≤ h 上1 -Δh and h 上≤ h 上2 -Δh (10)

[0047] Δh represents the margin of water depth to ensure safe navigation of a ship. The specific calculation method is shown in Equations (4), (5), and (6).

[0048] ② For downstream gate operations, when the gate operation begins at time t... 下 According to the lock operation process, the opening and closing time of the downstream gate is approximately t. 下1 The time it takes for a ship to reach the downstream channel control section of the lock after passing through it is approximately t. 下2 Based on the process of water depth change in the downstream channel of the lock generated in step 2 and equations (2) and (3), t is calculated. 下1 The water depth at the sill of the lower lock head is h. 下1 and t 下2 Water depth h at the downstream channel control section of the ship lock 下2 The maximum vessel draft control standard for this lock operation is determined to be h. 下 ,due:

[0049] h 下≤ h 下1 -Δh and h 下≤ h 下2 -Δh (11).

[0050] Specifically, the vessel lock passage sorting involves setting up virtual lines for vessel passage sorting in suitable waters upstream and downstream of the lock. The area within these lines is designated as the scheduling waters. By sensing the vessel's positioning information, the time it takes for the vessel to arrive at the scheduling waters after submitting its lock passage application is obtained, and the vessels are then sorted according to their passage order.

[0051] The principle of maximizing the utilization of the lock chamber area specifically refers to making slight adjustments to the order of ship passage through the lock based on the order of ship passage, so as to allow more ships to pass through the lock each time, thereby maximizing the utilization of the lock chamber area while ensuring fair passage of ships and taking efficiency into account.

[0052] The vessels passing through the lock and their order of passing through the lock refer to the specific list of vessels included in the current vessel passing plan and their specific lock order in the plan, determined based on the actual draft of the vessels and the draft control requirements for passing through the lock, and on the principle of maximizing the utilization of the lock chamber area.

[0053] In step 4, the vessel passage plan is dynamically adjusted based on the changing trends of channel depth and flow rate. Specifically, based on the water level-flow rate relationship function, the calculated channel depth downstream of the lock differs from the actual depth. The water depth at the downstream channel control section and the sill of the lower lock head are monitored in real time. Combined with the outflow from the dam and the changing trends of channel depth, the vessel passage plan to be executed is dynamically adjusted according to the following rules before the vessel departs from the lock:

[0054] ①: Let the real-time water depth at the downstream channel control section of the lock be h at the current moment. 实 Calculate the water depth as h 计 When h 实 ≥h 计 At that time, vessels currently awaiting departure can proceed through the lock as originally planned, and there is no need to adjust the lock passage plans for subsequent vessels.

[0055] ②: When h 实 Less than h 计 When the outflow from the hub shows an upward trend, for upstream vessels, the departure time of currently waiting vessels will be postponed until h 实 Increase to the same as h 计 When the numbers are equal, a departure instruction is issued to the vessel currently awaiting departure, and the lock passage plans for subsequent vessels are postponed accordingly.

[0056] ③: When h 实 Less than h 计When the outflow from the hub shows an upward trend, for downstream vessels, the exit time of the currently executing lock session will be postponed until h 实 Increase to the same as h 计 When the numbers are equal, a lock exit instruction is issued to the vessel, and the lock passage plan for subsequent vessels to be executed is postponed accordingly.

[0057] ④: When h 实 Less than h 计 When the outflow from the lock is decreasing, the water depth variation in the downstream channel is predicted based on the planned outflow. The first 1-2 vessels scheduled to depart sequentially will be suspended, and subsequent vessels scheduled to pass through the lock will be moved forward. When the outflow from the lock turns increasing and h 实 -Δh≥stop the execution of the maximum vessel draft control standard for lock sessions, and the vessels currently suspended from departure for 1-2 lock sessions will be transferred to the execution standard.

[0058] This invention discloses a method for improving the loading rate of ships passing through locks through dynamic draft control, with the following technical effects:

[0059] 1) Step 1 of the present invention establishes the water level-discharge relationship function of the downstream channel control section of the lock. By obtaining the outflow plan information of the hub, the water depth change process of the downstream channel of the lock during the specific implementation period of the current ship passage plan is calculated in advance, so that the implementation of dynamic draft control of ship passage is more scientific and more operable.

[0060] 2) Step 3 of the present invention, by predicting the process of water depth change in the downstream channel of the lock, implementing dynamic draft control, and generating a ship passage plan according to certain lock passage sorting rules, maximizes the utilization of channel water depth and lock chamber area under the premise of ensuring safe and fair ship passage, and promotes further improvement of ship passage loading rate and lock throughput capacity.

[0061] 3) Step 4 of the present invention involves implementing water depth monitoring of the downstream channel of the lock to keep track of the channel water depth in real time, and combining the discharge flow of the hub and the trend of channel water depth changes to scientifically adjust the lock passage plan of the ships to be executed, thereby further ensuring the safety of ships passing through the lock.

[0062] 4) This invention establishes a dynamic draft control model for locks, scientifically grasps the relationship between channel water level and flow rate, effectively utilizes real-time channel depth, and reasonably increases ship loading rate while ensuring navigation safety, thereby further enhancing lock throughput capacity and operational efficiency. Attached Figure Description

[0063] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0064] Example:

[0065] Taking a single-stage ship lock on one side of a navigation channel of a certain hub on the Yangtze River as the implementation target, such as... Figure 1 As shown, a method for improving the throughput capacity of a ship lock through dynamic draft control includes the following steps:

[0066] Step 1: Establish a dynamic draft control model for the lock based on constraints such as water level-flow relationship, lock operation conditions, ship passage scheduling rules, and ship draft control requirements;

[0067] Step 2: Collect the planned discharge flow of the hub and substitute it into the model to calculate and generate the process of water depth change in the downstream channel of the lock;

[0068] Step 3: Collect vessel lock passage declaration information, and determine the vessel lock passage plan based on the channel water depth change process and lock operation plan preparation rules in Step 2.

[0069] Step 4: Organize the passage of ships through the lock according to the ship passage plan determined in Step 3. During the implementation, monitor the water depth of the downstream channel in real time through the water level station near the control section of the downstream channel of the lock. Adjust the passage plan dynamically according to the water depth and flow rate change trend.

[0070] The method for establishing the water level-discharge relationship in step 1 is as follows:

[0071] Water level and flow rate observation samples were collected at the downstream channel control section of the ship locks. The discharge flow range for which dynamic draft control needs to be implemented at both ship locks is [5500m]. 3 / s,8500m 3 / s], according to 200-300m 3 The interval is 5500m / s. 3 / s to 8500m 3 Select 10-15 representative traffic values ​​Q from the / s traffic range. i Q i ∈[5500m 3 / s,8500m 3 / s], the downstream channel control section of the lock represents the flow set Q. i = (Q1, Q2, Q3, ... Q i Each representative flow corresponds to n. i Water level Z ni Then the corresponding value represents the flow rate Q. i Water level sample set Z ni =(Z i1 Z i2 Z i3 ...Z ini );

[0072] Take the representative flow Q i The corresponding water level sample set Z niBased on the hydrological frequency calculation method and the channel depth guarantee rate P, Q is calculated. i The corresponding water level is Z. i According to Q i With Z i Based on the continuity of water level and flow rate changes, a function relating water level Z and flow rate Q at the downstream channel control section of the lock is fitted:

[0073] Z = f(Q), Q i ∈[5500m 3 / s,8500m 3 / s] (1)

[0074] The lock operation conditions mentioned in step 1 include determining the water depth h1 of the lower lock sill and the water depth h2 of the downstream channel control section, then:

[0075] h1=Z-Z1 (2)

[0076] h2=Z-Z2 (3)

[0077] Where: Z1 is the elevation of the lower lock head threshold; Z2 is the maintenance elevation of the downstream channel control section of the lock.

[0078] In the embodiment, the lower gate threshold elevation of lock 1 is 34m (using the Wusong elevation, the same below), and the lower gate threshold elevation of lock 2 is 35m.

[0079] That is, the water depth of the lower lock sill of lock 1 is Z-34m, and the water depth of the lower lock sill of lock 2 is Z-35m.

[0080] The two locks share a pilot channel, and the downstream channel depth control section is located in the lower pilot channel. The maintenance elevation of the bottom of the channel at the channel depth control section is 35m, i.e., h2 = Z - 35m.

[0081] The ship draft control requirements mentioned in step 1 include determining the margin of safety Δh required for safe navigation. For ships passing through locks, the following applies:

[0082] Δh=δ1+δ2+δ3 (4)

[0083] Wherein, δ1 is the amount of sinking during ship navigation;

[0084] According to the method for calculating the sinking of a ship during navigation, the expression for δ1 is:

[0085] δ1=(-15.26x 2 +3.923x+0.267)×H (5)

[0086] For vessels passing through the lock, the variable x is calculated as follows:

[0087]

[0088] Where v is the ship's speed, and is taken as the maximum speed limit for ships passing through the lock. The maximum speed limit for ships passing through lock 1 and lock 2 is 1m / s.

[0089] g is the acceleration due to gravity, which is 9.8 m / s². 2 ;

[0090] H takes over the ship lock lower gate sill water depth h1;

[0091] S is the underwater cross-sectional area of ​​the lock chamber, and S = dh1, where d is the width of the lock chamber. For lock 1, d is taken as 34m, and for lock 2, d is taken as 34m.

[0092] Let s be the underwater cross-sectional area of ​​the vessel passing through the lock. Assume the maximum beam of the vessel passing through the lock is d1, and the maximum draft of the lock is h3, then s = d1 h3. For vessels passing through locks 1 and 2, the maximum beam is 19.2m and the maximum draft is 4.3m. Therefore, s = 19.2m × 4.3m = 85.56m. 2 .

[0093] δ2 is the margin for ships not touching the bottom, which is generally determined based on the navigation standards, channel grade, riverbed composition, and water depth fluctuation during lock discharge. According to the navigation standards, channel grade, and riverbed composition corresponding to locks 1 and 2, the margin for ships not touching the bottom should be 0.5m. Considering the water depth fluctuation of 0.1m-0.3m during lock discharge, and for safety reasons, δ2 = 0.8m is taken.

[0094] δ3 is the safe margin of water depth for ships passing through the lock. Based on the trend of the outflow of the hub and the empirical value of the ship departure and arrival cycle through the lock, δ3 for lock 1 and lock 2 in this embodiment is 0.3m.

[0095] The rules for compiling the lock operation plan in step 3 are as follows:

[0096] 1) Based on the lock operation status, estimate the number of lock operations (M) and the number of vessels passing through the lock during the current planned vessel passage period, including the number of upstream lock operations (M). s Number of ships going uphill N s and the number of down-going gates M x Number of ships going downhill N x ;

[0097] 2) Based on the current lock schedule execution status, estimate the start time of each lock session in the current vessel passage plan;

[0098] 3) Based on the requirements for ship draft control, the order of ship passage through the lock, and the principle of maximizing the utilization rate of the lock chamber area, determine the ships passing through the lock and the order of ship passage through the lock.

[0099] The ship draft control requirements mentioned in the lock operation plan preparation rules in step 3 are as follows:

[0100] ①: For upstream vessels, when the lock operation begins at time t 上 According to the lock operation process, the opening and closing time of the downstream gate is approximately t. 上4 For lock 1, we have t 上 -t 上4 =15min;

[0101] Let the average interval of the lock operation be T1. In this example, the average interval of lock 1 is 90 minutes and the average interval of lock 2 is 60 minutes.

[0102] Let the average period of ship departure and arrival be T2. In this example, the average period of ship departure and arrival between lock 1 and lock 2 is 180 minutes.

[0103] According to the ship passage scheduling rules, in order to ensure the efficient and orderly operation of the lock, the time for a ship to arrive at the berth is approximately t. 上3 Then we have:

[0104] t 上3 =t 上 -T1 (7)

[0105] The ship's departure time is approximately t 上1 Then we have:

[0106] t 上1 =t 上3 -T2 = t 上 -T1-T2 (8)

[0107] Let L be the distance from the downstream channel control section of the lock to the lock's pier, and V be the average speed of the vessel in the channel. 平 The ship arrives at the downstream channel control section of the lock at t. 上2 In the embodiment, the time it takes for a ship to travel from the downstream channel control section of the lock to the berthing pier is approximately 30 minutes, therefore:

[0108] t 上2 = t 上3 -L / V 平 = t 上 -T1-30min (9)

[0109] Based on the process of water depth change in the downstream channel of the lock generated in step 2 and the calculation formulas (2) and (3), t is estimated. 上2 Water depth h at the downstream channel control section of the ship lock 上2 and t 上4 The water depth at the sill of the lower lock head is h. 上1The maximum vessel draft control standard for this lock operation is determined to be h. 上 ,due:

[0110] h 上≤ h 上1 -Δh and h 上≤ h 上1 -Δh(10)

[0111] ②: For downstream gate operations, when the gate operation starts at time t 下 According to the lock operation process, the opening and closing time of the downstream gate is approximately t. 下1 The time it takes for a ship to reach the downstream channel control section of the lock after passing through it is approximately t. 下2 Based on the process of water depth change in the downstream channel of the lock generated in step 2 and the calculation formulas (2) and (3), t is estimated. 下1 The water depth at the sill of the lower lock head is h. 下1 and t 下2 Water depth h at the downstream channel control section of the ship lock 下2 The maximum vessel draft control standard for this lock operation is determined to be h. 下 ,due:

[0112] h 下≤ h 下1 -Δh and h 下≤ h 下1 -Δh(11).

Claims

1. A method for improving the loading rate of ships passing through locks through dynamic draft control, characterized in that... Includes the following steps: Step 1: Based on the water level-flow relationship, lock operation conditions, ship passage scheduling rules, and ship draft control requirements, establish a dynamic draft control model for the lock. Step 2: Collect the planned discharge flow of the hub, input it into the dynamic draft control model of the lock, and calculate the process of water depth change in the downstream channel of the lock; Step 3: Collect vessel lock passage declaration information, and determine the vessel lock passage plan based on the water depth change process of the downstream channel of the lock in Step 2 and the lock operation plan preparation rules; In step 1, the method for establishing the water level-flow rate relationship is as follows: Water level and flow rate observation samples were collected at the downstream channel control section of the lock. The downstream flow rate interval requiring dynamic draft control was defined as [Q1, Q2]. At regular intervals, i representative flow rates Q1 and Q2 were selected from the flow rate interval between Q1 and Q2. i ,have The downstream channel control section of the lock represents the flow set Q. i = (Q1, Q2, Q3, ... Q i Each representative flow corresponds to n i Water level Z ni Then the corresponding value represents the flow rate Q. i Water level sample set Z ni =(Z i1 Z i2 Z i3 ...Z ini ); Take the representative flow Q i The corresponding water level sample set Z ni Based on the hydrological frequency calculation method and the channel depth guarantee rate P, Q is calculated. i The corresponding water level is Z. i According to Q i With Z i Based on the continuity of water level and flow rate changes, a function relating water level Z and flow rate Q at the downstream channel control section of the lock is fitted: ， （1）； In formula (1): It is the functional relationship between the water level Z at the downstream channel control section of the lock and the discharge flow Q of the lock hub; In step 1, the ship draft control requirements include determining the allowable water depth Δh to ensure safe navigation of the ship. For ships passing through locks, this means: Δh=δ1+δ2+δ3(4; Among them, δ1 is the amount of sinking during ship navigation; δ2 is the amount of margin for ship not touching the bottom; and δ3 is the amount of margin for water level fluctuation in the channel. According to the method for calculating the sinking of a ship during navigation, the expression for δ1 is: δ1=(-15.26x 2 +3.923x+0.267)×H(5); For vessels passing through the lock, the variable x is calculated as follows: （6）； Where v is the ship's speed, taken as the maximum speed limit for ships passing through the lock; g is the acceleration due to gravity; H is the water depth h1 at the lower sill of the lock; S is the underwater cross-sectional area of ​​the lock chamber, with S=dh1; d is the width of the lock chamber; s is the underwater cross-sectional area of ​​the ship passing through the lock, assuming the maximum ship width among the ship types passing through the lock is d1 and the maximum draft limit of the lock is h3, taken as s=d1h3.

2. The method for improving the loading rate of a ship through lock passage by dynamic draft control according to claim 1, characterized in that: It also includes step 4: organizing ships to pass through the lock according to the ship passage plan determined in step 3, monitoring the water depth of the downstream channel in real time during the implementation process, and dynamically adjusting the ship passage plan according to the changes in channel water depth and flow.

3. The method for improving the loading rate of ships through lock passage by dynamic draft control according to claim 1, characterized in that: In step 1, the lock operation conditions include determining the water depth h1 of the lower lock sill and the water depth h2 of the downstream channel control section, then: h1=Z-Z1(2) h2=Z-Z2(3; Where: Z1 is the elevation of the lower lock head threshold; Z2 is the maintenance elevation of the downstream channel control section of the lock.

4. The method for improving the loading rate of ships through lock passage by dynamic draft control according to claim 1, characterized in that: In step 3, the rules for compiling the lock operation plan are as follows: 1) Based on the lock operation status, calculate the number of lock operations (M) and the number of vessels passing through the lock during the current planned vessel passage period. The number of lock operations (M) and the number of vessels passing through the lock (N) include the number of upstream lock operations (M). s Number of ships going uphill N s and the number of down-going gates M x Number of ships going downhill N x ; 2) Based on the current lockage schedule execution status, calculate the start time for each lockage session in the current vessel passage plan; 3) Based on the requirements for ship draft control, the order of ship passage through the lock, and the principle of maximizing the utilization rate of the lock chamber area, determine the ships passing through the lock and the order of ship passage through the lock.

5. The method for improving the loading rate of a ship through lock passage by dynamic draft control according to claim 4, characterized in that: The ship's draft control requirements are as follows: ① For upstream vessels, when the lock operation begins at time t 上 According to the lock operation process, the opening and closing time of the downstream gate is approximately t. 上4 Let the average interval between lock operations be T1, and the average departure and arrival time of ships be T2. According to the ship passage scheduling rules, to ensure the efficient and orderly operation of the lock, the time for a ship to arrive at the berth is approximately t. 上3 Then we have: t 上3 =t 上 -T1 (7); The ship's departure time is approximately t 上1 Then we have: t 上1 =t 上3 -T2=t 上 -T1-T2(8); Let L be the distance from the downstream channel control section of the lock to the lock's pier, and V be the average speed of the vessel in the channel. 平 The ship arrives at the downstream channel control section of the lock at t. 上2 Then we have: t 上2 =t 上3 -L / V 平 =t 上 -T1-L / V 平 (9); Based on the water depth change process of the downstream channel of the lock generated in step 2 and equations (2) and (3), t is calculated. 上2 Water depth h at the downstream channel control section of the ship lock 上2 and t 上4 The water depth at the sill of the lower lock head is h. 上1 The maximum vessel draft control standard for this lock operation is determined to be h. 上 Then we have: h 上≤ h 上1 -Δh and h 上≤ h 上2 -Δh (10); Δh represents the margin of safety for a ship's navigation; ② For downstream gate operations, when the gate operation begins at time t... 下 According to the lock operation process, the opening and closing time of the downstream gate is approximately t. 下1 The time it takes for a ship to reach the downstream channel control section of the lock after passing through it is t. 下2 Based on the process of water depth change in the downstream channel of the lock generated in step 2 and equations (2) and (3), t is calculated. 下1 The water depth at the sill of the lower lock head is h. 下1 and t 下2 Water depth h at the downstream channel control section of the ship lock 下2 The maximum vessel draft control standard for this lock operation is determined to be h. 下 Then we have: h 下≤ h 下1 -Δh and h 下≤ h 下2 -Δh (11).

6. The method for improving the loading rate of ships through lock passage by dynamic draft control according to claim 1, characterized in that: In step 4, the vessel passage plan is dynamically adjusted based on the changing trends of channel depth and flow rate; the details are as follows: ①: Let the real-time water depth at the downstream channel control section of the lock be h at the current moment. 实 Calculate the water depth as h 计 When h 实 ≥h 计 At that time, vessels currently awaiting departure can proceed through the locks as originally planned, and there is no need to adjust the lock passage plans for subsequent vessels. ②: When h 实 Less than h 计 When the outflow from the hub shows an upward trend, for upstream vessels, the departure time of currently waiting vessels will be postponed until h 实 Increase to the same as h 计 When the numbers are equal, a departure instruction is issued to the vessel currently awaiting departure, and the lock passage plans of subsequent vessels are postponed accordingly. ③: When h 实 Less than h 计 When the outflow from the hub shows an upward trend, for downstream vessels, the exit time of the currently executing lock session will be postponed until h 实 Increase to the same as h 计 When the numbers are equal, a lock exit instruction is issued to the vessel, and the lock passage plan for subsequent vessels to be executed is postponed accordingly. ④: When h 实 Less than h 计 When the outflow from the lock is decreasing, the water depth variation in the downstream channel is predicted based on the planned outflow from the lock. The first 1-2 lock sessions that are currently scheduled to depart will be suspended, and the subsequent lock passage plans will be implemented in advance. When the outflow from the hub turns to an upward trend and h 实 -Δh≥stop the execution of the maximum vessel draft control standard for lock sessions, and the vessels currently suspended from departure for 1-2 lock sessions will be transferred to the execution standard.

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