Ship safety gate passing judgment method based on gate opening and closing and ship navigation conditions

Abstract

The invention discloses a ship safety gate passing judgment method based on gate opening and closing and ship navigation conditions, and belongs to the technical field of water traffic safety. The method comprises the following steps: establishing a gate passing safety control index system comprising a lock head water level difference delta h, a lock chamber water flow velocity vw, a ship speed vs and a ship spacing delta L; according to a navigation water level range and a navigation channel condition, formulating a limit value of each index as a gate passing safety judgment standard; setting gate passing operation conditions including a gate passing opening condition, a ship navigation condition and a gate passing closing condition; and based on the ship lock grade, the lock chamber width and the locked ship type of the actual engineering, applying the gate passing safety judgment standard and the gate passing operation condition to obtain a ship gate passing safety judgment result. The method has the advantages of being high in applicability, easy and convenient to implement, remarkable in efficiency and the like, scientific and reliable technical support is provided for ship lock passing operation, and meanwhile important reference is provided for navigation dispatching management and safety guarantee.

Description

Technical Field

[0001] The invention belongs to the technical field of water transportation safety, and in particular relates to a method for judging safe ship gate passage based on gate opening and closing and ship navigation conditions. Background Art

[0002] The ship lock is an important navigation structure to ensure that ships can pass smoothly through the water level difference area in the waterway, and it is also a key control node in the waterway transportation network. Under normal circumstances, due to the large water level difference between the upstream and downstream, the ship lock uses the principle of a communicating vessel to adjust the water level by filling or discharging water into the lock chamber to achieve a segmented water level balance between the upstream and the lock chamber, and between the lock chamber and the downstream, so that the lock chamber becomes a "water ladder" for ships to rise and fall and a transfer station for passing through the lock. This mode of operation is called the normal mode. However, in special circumstances, when the upstream and downstream water levels are equal or close, in order to improve navigation efficiency, the upper and lower gates can be directly opened to connect the upstream and downstream water bodies. When the water flow in the lock chamber tends to be stable, the ship can pass through the lock chamber freely. At this time, the lock chamber is equivalent to a shallow and narrow channel. This mode of operation is called the lock mode, which is a special form of ship lock operation.

[0003] At present, there are many deficiencies in the judgment method of safe operation of ship locks, which are mainly reflected in the lack of systematization and standardization in safety control indicators, evaluation criteria and operating conditions. Existing research and practice show that although the operation of ship locks can significantly improve the navigation efficiency, the safety risks associated with it are relatively high, especially when the gate is opened and closed in the dynamic water environment and the ship is sailing in the shallow and narrow channel of the lock chamber, the operating conditions are more complicated. For the safety of gate opening and closing, the existing understanding is relatively unified, that is, the maximum opening and closing force during the operation of the gate shall not exceed the rated capacity of the gate hoist, but the understanding of ship navigation safety is still insufficient, mainly relying on the flow velocity experience value to limit the flow velocity conditions in the lock chamber. However, this method fails to fully reflect the blocking effect of the lock chamber as a typical shallow and narrow channel on the ship, ignores the actual navigation state and force characteristics of the ship in the special flow field, and is difficult to accurately evaluate the navigation safety. In addition, the existing research lacks in-depth analysis of the hydrodynamic environment when the ship passes through the lock chamber, and has not formed a unified understanding of the specific impact of water flow disturbance on ship navigation in the lock mode.

[0004] Although the existing patents (CN201910119402.6 and CN201910982022.5) have proposed some methods for determining the safe operation conditions of the gate, they all have limitations. Patent (CN201910119402.6) studies the relationship between the gate opening and closing force and the water level difference at the gate head and the corresponding flow field changes in the lock chamber through physical model experiments. The research method is reliable and the data is accurate, but the human, material and time costs required for the experiment are high, and it is difficult to be widely used. Patent (CN201910982022.5) quickly calculates the critical water level difference for safe operation of the gate by establishing an empirical formula, which is highly efficient, but its method is only applicable to the case where the ship lock is the only flow channel, and lacks applicability to complex ship locks with multiple flow channels (such as control gates, sluice gates, etc.). In addition, both studies used the water level difference before and after the triangular gate as the safety control index for lock opening, but did not fully consider the complex flow field in the lock chamber and its impact on the navigation stability of ships, nor did they fully cover a variety of lock structures and operating conditions. Overall, the current methods still have much room for improvement in terms of scope of application, versatility, and comprehensive consideration of complex conditions.

[0005] In view of the fact that the current research on lock safety is still in the engineering practice stage and there is no relevant technical standard to refer to for lock safety control, it is necessary to propose a new method for judging lock safety based on the engineering practice experience of lock operation, fully consider the safety of gate opening and closing and ship navigation safety, so as to improve the safety of lock operation and provide a reference for the further promotion of lock operation management and lock mode. Summary of the invention

[0006] In view of the shortcomings of the current methods in the prior art in terms of the systematicness of safety control indicators, the standardization of evaluation criteria, the applicability of complex conditions, and the comprehensive consideration of the blocking effect of ships in shallow and narrow channels, the present invention provides a method for judging the safe passage of ships through gates based on gate opening and closing and ship navigation conditions.

[0007] The present invention is implemented as follows: a method for judging safe passage of ships based on gate opening and closing and ship navigation conditions, characterized in that the method comprises the following steps: S1. establishing a gate head water level difference Δh, a gate chamber water flow velocity v w , ship speed v s and the ship spacing ΔL, the lock safety control index system; S2. According to the navigable water level range and channel conditions, the limit values ​​of each index are formulated as the lock safety evaluation criteria; S3. The lock operation conditions including the lock opening conditions, ship navigation conditions and lock closing conditions are set; S4. Based on the actual project's ship lock grade, lock chamber width and ship type passing through the lock, the lock safety evaluation criteria and lock operation conditions are applied to obtain the ship lock safety judgment result.

[0008] In the above technical solution, preferably, the gate safety control index system includes gate opening and closing safety control index and ship navigation safety control index, the gate is a triangular gate, the gate opening and closing safety control index is the gate head water level difference Δh at the beginning and end of the gate opening, and the ship navigation safety control index is the gate chamber water flow velocity v during the gate opening process. w , ship speed v s , ship spacing ΔL.

[0009] In the above technical solution, preferably, in step S2, the limit value Δh of the water level difference at the gate head is formulated according to the gate chamber width classification. lim : When the lock chamber width is 23m, Δh lim =0.30m, when the lock chamber width is 16m, Δh lim =0.24m, when the lock chamber width is 12m, Δh lim =0.20m.

[0010] In the above technical solution, preferably, the limit values ​​v of the water flow velocity in the lock chamber and the ship speed are formulated according to the classification of the ship lock level. slim : When the lock level is Class III and Class IV, v slim =1.6m / s, when the lock level is V-level lock, v slim =1.4m / s; when the ship lock level is Class III ship lock, v s ≤1.6m / s, when the lock level is IV, v s ≤1.5m / s, when the lock grade is V-class lock, v slim =1.4m / s; According to the classification of ship types, the limit value ΔL of the ship spacing is established lim , when the ship type is fleet and heavy-load ship, ΔL lim =1 times the ship length, when the ship type is an empty ship, ΔL lim = 2 times the length of the ship.

[0011] In the above technical solution, preferably, the gate opening condition is Δh≤Δh lim ; The ship navigation condition is v s ≤v slim And ΔL ≥ ΔL lim The gate closing condition is v w =v wlim .

[0012] In the above technical solution, preferably, the method for determining the gate opening and closing safety control index is:

[0013] The opening and closing force of the triangular gate is calculated as follows:

[0014]

[0015] Where:

[0016] T is the opening and closing force of the triangular gate, in kN;

[0017] K is the safety factor;

[0018] ∑M is the total resistance moment of opening or closing the triangular gate, in kN;

[0019] R is the arm from the traction force to the rotation center, in m;

[0020] Total resistance moment ∑M=M1+M2+M3+M4+M5, where M1 is the friction resistance moment of the top pivot and the bottom pivot; M2 is the friction resistance moment of the bottom water stop; the middle and side of M3 are the friction resistance moment of the surface water stop; M4 is the eccentric resistance moment of the water pressure caused by the asymmetric horn; and M5 is the water flow resistance moment;

[0021] When the gate is opened and closed, the middle and side water stops are instantly disconnected or contacted, and M3 is negligible; assuming that the triangular gate horns are arranged symmetrically, then M4 = 0; M1, M2, and M5 are related to the gate structure layout, the gate deadweight, and the initial water flow state when the gate is opened and closed; the gate opening and closing force is expressed as a function of the following water flow force:

[0022] T=f(p2) (2)

[0023] The water flow force is calculated as follows:

[0024]

[0025] Where:

[0026] p2 is the water flow force; the unit is kN;

[0027] C w is the water flow resistance coefficient;

[0028] ρ is the water density, in m 3 / s;

[0029] v is the water flow velocity in the triangular gate gap section, in m / s;

[0030] A is the projected area of ​​the calculation component on the plane perpendicular to the flow direction, in m 2 ;

[0031] A = bh;

[0032] b is the width of the lock chamber, in m;

[0033] h is the water depth of the channel, in meters;

[0034] During the opening and closing process of the triangular gate, the flow velocity of the gate gap section is related to the water level difference on both sides of the gate. Ignoring the influence of the gate gap section contraction and the gate opening and closing inertia, the flow velocity of the gate gap section is expressed as a function of the water level difference on both sides of the gate. Let Δh be the gate head water level difference at the beginning and end of the gate opening, then:

[0035]

[0036] The calculation formula of water flow force is as follows:

[0037] p2=C w ρgbΔhh (4)

[0038] The calculation formula of the gate opening and closing force is obtained from equations (2) and (4) as follows:

[0039] T=f(b·Δh·h) (4)

[0040] When the reduction coefficient of the rated capacity of the gate hoist is determined, for the ship lock project with a determined lock chamber width, there is a critical water level difference on both sides of the gate under different channel water depths. Considering the convenience of scheduling and management, the water level difference at the gate head at the beginning and end of the gate opening is used as the main control indicator for the safety of gate opening and closing.

[0041] The method for judging safe passage of ships through the lock based on the gate opening and closing and the ship's navigation conditions has the following significant advantages and effects:

[0042] This method establishes a gate safety control index system including the gate head water level difference, gate chamber flow velocity, ship speed and ship spacing, and comprehensively considers the key factors affecting the safety of ship gate passage from multiple dimensions. This systematic index system not only covers the core elements of gate opening and closing safety, but also fully considers the complex hydrodynamic environment in which ships are located during the gate passage process, making the safety assessment of gate operation more scientific and accurate.

[0043] This method proposes specific recommended evaluation criteria for each safety control indicator, providing an operational technical basis for actual operation. By quantifying the scope and restrictions of each indicator, such as the safe range of the water level difference at the gate head, the maximum flow velocity allowed in the gate chamber, and the reasonable speed and spacing requirements for ships passing through, it can effectively avoid safety risks caused by subjective judgment and provide support for the standardization of gate operation.

[0044] This method is based on the design parameters of the lock and the basic types of ships passing through the lock, and flexibly sets the corresponding lock operation conditions. It is applicable to different types of locks and a variety of navigable ships. This method can adapt to various complex working conditions.

[0045] The core logic of this method is clear, the calculation is simple, and it does not rely on complex experimental devices or model verification, so it is suitable for direct application in engineering practice. Its convenience greatly reduces the implementation cost, allowing the lock management to quickly evaluate and adjust the lock operation conditions, thereby improving the operation efficiency.

[0046] With the help of scientific gate clearance judgment methods, managers can clearly define safety boundaries in operation and scheduling, avoiding efficiency losses or safety accidents caused by overly conservative or risky operations. By monitoring and analyzing control indicators, operating parameters can be dynamically adjusted to significantly improve navigation efficiency while ensuring safety.

[0047] Since this method constructs a standardized index system and evaluation criteria, it provides a solid foundation for further research on the navigation safety of ship locks. Its scalability allows the control standards and calculation methods to be further optimized with technological progress and data accumulation, promoting the sustainable development of ship lock navigation technology.

[0048] The method for judging safe ship passage through the locks based on gate opening and closing and ship navigation conditions not only solves the shortcomings of traditional methods in terms of systematic indicators and standardization of evaluation, but also has the advantages of strong applicability, simple implementation and significant efficiency. It provides scientific and reliable technical support for the operation of the locks, and also provides an important reference for navigation scheduling management and safety assurance.

[0049] In addition to the above effects, by accurately setting the lock operation conditions, especially when the upstream and downstream water level difference is small, the feasibility of lock opening can be quickly determined, and unnecessary filling and discharge operation time can be reduced. It effectively shortens the waiting time of ships and improves navigation efficiency, which is particularly suitable for high-frequency lock operation needs in busy waterways. By scientifically judging the lock operation conditions and directly implementing the lock operation when the water level difference is small, the operation frequency of pumping stations or hoists can be reduced, and energy consumption and facility operation and maintenance costs can be significantly reduced, which is economically beneficial. In the face of hydrological fluctuations caused by climate change (such as flow changes or water level fluctuations), this method can more flexibly adapt to changes in hydrological conditions and ensure the safety and stability of lock operation through parameterized indicator adjustment and dynamic monitoring. In the lock mode, the natural conditions of small water level difference are used to reduce filling and discharge operations, which not only improves the operation efficiency, but also retains the water resources upstream and downstream of the lock to the greatest extent, especially in the dry season or areas with high water conservation requirements, with significant environmental benefits. Through a standardized indicator system, this method can quickly determine the operation risk in the event of sudden water level changes or equipment failures, and guide managers to take corresponding measures. For example, it can quickly evaluate the safety of gate opening and closing or the conditions for ships to pass through, reducing safety accidents caused by slow decision-making. The quantitative indicators and simple algorithms of the lock judgment method are very suitable for integration into modern intelligent management systems. Combined with sensor data and real-time monitoring platforms, the automatic control of lock operation can be realized, providing basic support for the construction of smart waterways and locks. This method helps to identify potential safety hazards through clear indicator evaluation criteria. For example, by controlling the flow rate in the lock chamber and the distance between ships, the risk of ship collision, instability or touching the gate is reduced, thereby comprehensively improving operational safety. For locks with complex structures such as control gates or sluice gates, this method supports more complex design layouts and functional optimization through flexible parameter adjustment, providing a technical basis for the construction or reconstruction of new locks. By clarifying the speed, spacing and flow field requirements during the navigation of ships, it provides clearer operating instructions for crew members, reduces operational errors caused by lack of experience or misjudgment, and further ensures the safety of ship navigation. The standardized advantages of this method in the indicator system and evaluation criteria can provide a reference for the formulation of domestic and international navigation standards. Especially in international rivers or cross-border waterways, a unified safety judgment method can help promote navigation management cooperation and technology sharing among multiple countries.

[0050] In summary, this method can not only improve the efficiency and safety of ship lock operation, but also has wide application value in environmental protection, energy saving, emergency management, intelligent development and international cooperation. These extended advantages and effects further highlight the comprehensiveness and long-term significance of the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a schematic diagram of the working principle of the ship lock;

[0052] Figure 2It is a bird's-eye view of the water flow near the gates at the beginning and end of the gate opening;

[0053] Figure 3 yes Figure 2 BB cross-section diagram;

[0054] Figure 4 yes Figure 1 CC profile of ;

[0055] Figure 5 yes Figure 1 DD profile diagram;

[0056] Figure 6 It is the distribution diagram of the limit values ​​of gate operation control indicators in existing engineering practices;

[0057] Figure 7 It is the distribution diagram of the gate safety control index system and its evaluation criteria;

[0058] Figure 8 It is a schematic diagram of the method for setting the operating conditions for the ship lock. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0060] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In order to further illustrate the structure of the present invention, the detailed description is as follows in conjunction with the accompanying drawings:

[0061] A method for judging safe passage of a ship through a lock based on lock opening and closing and ship navigation conditions, the method comprising the following steps:

[0062] S1. Establish the water level difference Δh at the gate head and the water flow velocity v in the gate chamber. w , ship speed v s The safety control index system for gate opening and closing includes the gate opening and closing safety control index and the ship navigation safety control index.

[0063] Specifically, the safety of ship lock operation requires ensuring the safety of gate opening and closing and the navigation safety of ships. The water level difference Δh at the beginning and end of the lock opening is used as the safety control index of the gate opening and closing, and the water flow velocity v in the lock chamber during the lock opening process is used as the safety control index of the lock opening and closing. w , ship speed v s , and ship spacing ΔL are used as ship navigation safety control indicators.

[0064] The working principle of ship lock is shown in Figure 1 In the lock-through mode, the upper and lower gates of the ship lock are opened, the upstream and downstream water bodies of the ship lock are directly connected, and ships can pass through the lock chamber freely. However, since the gates need to be opened and closed in a dynamic water environment, and ships need to navigate in the shallow and narrow channel of the lock chamber, the gate operation conditions and ship navigation conditions are relatively complex. The safety of lock-through operation requires the safety of gate opening and closing and ship navigation. The specific analysis is as follows:

[0065] About gate opening and closing safety:

[0066] In this embodiment, the gate is a triangular gate, which is the preferred gate type for ship lock projects with gate opening conditions. At the start and end of the gate opening, the relative state of the triangular gate, the gate head, and the water flow can be seen. Figure 2 , Figure 3 The opening and closing force of the triangular gate is calculated as follows:

[0067]

[0068] Where T is the closing force of the triangular gate (kN), K is the safety factor, ∑M is the total resistance torque for opening or closing the gate (kN·m); and R is the arm from the traction force to the rotation center (m).

[0069] Among them, the total resistance torque ∑M generally includes the friction resistance torque M1 of the top pivot and the bottom pivot, the friction resistance torque M2 of the bottom water stop, the friction resistance torque M3 of the middle and side water stops, the water pressure eccentric resistance torque M4 caused by the asymmetric horn, and the water flow resistance torque M5, that is, ∑M=M1+M2+M3+M4+M5.

[0070] When the gate is opened and closed, the middle and side water stops are instantly disengaged or contacted, and the friction resistance moment M3 is almost non-existent and can be ignored. For most triangular gates, the gate horns are arranged symmetrically, that is, M4 = 0. The remaining resistance moments are related to the gate structure layout, the gate deadweight and the initial water flow state when the gate is opened and closed. For the gates that have been planned, their structural layout and deadweight are both determined parameters, and under normal circumstances, the water flow resistance moment accounts for the vast majority of the total resistance moment, so the gate opening and closing force can be expressed as a function of the water flow force:

[0071] T=f(p2) (2)

[0072] The water flow force is calculated as follows:

[0073]

[0074] In the formula, C w is the water flow resistance coefficient, which is related to the retaining area of ​​the plane truss; ρ is the water density (m 3 / s); v is the flow velocity of the triangular gate gap section (m / s); A is the projected area of ​​the calculation component on the plane perpendicular to the flow direction (m 2 ), which is the product of the channel depth and the lock chamber width, expressed as A=bh.

[0075] During the opening and closing process of the triangular gate, the flow velocity of the gate gap section is related to the water level difference on both sides of the gate. Ignoring the influence of the gate gap section contraction and the gate opening and closing inertia, the flow velocity of the gate gap section can be roughly expressed as a function of the water level difference on both sides of the gate, that is, The water flow force can be roughly expressed as:

[0076] p2=C w ρgb·Δh·h (4)

[0077] Combining equations (2) and (4), the gate opening and closing force can be expressed as a function of the gate chamber width, the water level difference on both sides of the gate, and the channel depth, as follows:

[0078] T=f(b·Δh·h) (5)

[0079] According to formula (5), when the rated capacity reduction coefficient of the gate hoist is determined, for a ship lock project with a determined lock chamber size, there is a critical water level difference on both sides of the gate under different water depth conditions. In engineering practice, considering the convenience of dispatching and management, the minimum value of the critical water level difference between the upper and lower gate heads within the navigable water level range is often used as the critical condition for gate opening and closing safety under the gate opening mode. That is, the gate head water level difference at the beginning and end of the gate opening is used as the gate opening and closing safety control index.

[0080] Regarding ship navigation safety:

[0081] During the lock opening process, when the ship is sailing freely in the lock chamber, it is not only affected by the shallow water effect, but also by the shore effect, which increases the ship's navigation resistance, sinking amount and poor maneuverability. Figure 4 , Figure 5 In restricted waterways, the channel section coefficient (A w / A s ) is an important factor affecting the dynamic characteristics and maneuverability of ships. The smaller the channel section coefficient, the more significant the blocking effect of the channel on the ship.

[0082] In order to ensure the safety of ship navigation, existing engineering practices often limit the flow rate of the lock chamber. Usually, a safety reduction factor is considered as the flow rate limit of the lock chamber based on the flow rate limit of the pilot channel. For example, the previous references "Jiangyin Ship Lock Flow Condition Test" and "Ship Lock Safe Operation Test under Opening Condition" refer to the control standards of the pilot channel entrance section, taking safety factors of 0.75 and 0.80 respectively, requiring the lock chamber flow rate v wlim ≤1.50m / s,vwlim ≤1.60m / s; Reference to the literature "Triangle Gate Lock Opening Operation Conditions Test Study" and the control standards of the pilot channel braking section and berthing section, take the safety factor of 0.83, and require the chamber flow velocity v wlim ≤0.42m / s. The published patents (application numbers CN201910982022., CN201910119402.6) refer to the control standard of the pilot channel gate section, the safety factor is 1.0, and the flow rate limit condition of the lock chamber is set to v wlim =2.0m / s.

[0083] Under the normal operation mode of the ship lock, the ship starts to slow down when sailing from the upstream and downstream channels to the pilot channel entrance area, then sails through the pilot channel braking section to the mooring section, and the speed gradually drops to 0. After that, it needs to wait for the filling and discharge of the lock chamber to be completed before entering the lock chamber. The flow rate limit of the pilot channel braking section and the mooring section is to avoid excessive water flow force on the ship and cause the mooring force to exceed the standard, so the control standard is relatively strict. Under the lock operation mode, the ship directly passes through the lock chamber. According to the ship's motion state in the lock mode, the lock chamber flow rate limit is relatively reasonable with reference to the pilot channel entrance section, and the influence of the lock chamber section coefficient on the ship's navigation must be considered.

[0084] The navigation state of the ship in the lock chamber section should be controlled by the standard of not hitting the wall, not touching the bottom and moving upstream smoothly. For a certain ship type, under certain channel parameter conditions, the ship's navigation resistance, sinking amount and rudder effect are functions of the speed. The ship sailing in the lock chamber must maintain a certain speed to maintain the rudder effect and pass through the lock chamber upstream, but it cannot be too fast to prevent hitting the wall or touching the bottom. The ship's speed should be within an appropriate speed range, that is, a safe speed range. The speed is the speed of the ship relative to the shore, which includes the influence of the water flow. When downstream, the speed is equal to the ship speed plus the flow speed, and when upstream, the speed is equal to the ship speed minus the flow speed. In addition, in order to ensure that there is enough maneuvering space and reaction time between ships, a sufficient longitudinal safety distance should be maintained between ships. Based on this, the navigation state of the ship in the lock chamber can be expressed as the lock chamber section coefficient (n), the water flow velocity (v w ), ship speed (v s ) and the ship spacing (ΔL) as follows:

[0085] N=f(n,v w ,v s ,ΔL) (6)

[0086] According to formula (6), in order to determine the size of the lock chamber and the type of ship, when a ship directly passes through the lock, restrictions must be placed on the lock chamber flow velocity, ship speed, and ship spacing. That is, the lock chamber water flow velocity v during the lock passage process is w , ship speed v s , and ship spacing ΔL are used as ship navigation safety control indicators.

[0087] S2. According to the navigable water level range and channel conditions, the limit values ​​of each indicator are formulated as the safety evaluation criteria for lock opening. The limit values ​​of each indicator are as follows:

[0088] The control standard of the water level difference index at the gate is classified according to the width of the gate chamber. The water level difference limit values ​​corresponding to the gate chamber width b = 23m, 16m, and 12m are Δh respectively. lim =0.30m, 0.24m, 0.20m.

[0089] The control standard of chamber flow velocity index is classified according to the lock grade. For Class III and IV locks, the chamber flow velocity limit value is v wlim =1.6m / s, for Class V ship locks, the flow velocity limit value of the lock chamber is v wlim =1.4m / s

[0090] The ship speed control standards are classified according to the lock level. For Class III, IV, and V locks, the ship speed limit values ​​are v slim =1.6m / s, 1.5m / s, 1.4m / s.

[0091] The control standard of ship spacing index is classified according to the type of ships passing through the lock. For fleets and heavy-loaded ships, the limit value of ship spacing is ΔL lim = 1 times the ship length. For an unladen ship, the limit value of the distance between ships is ΔL lim = 2 times the length of the ship.

[0092] The distribution of the limit values ​​of gate operation control indicators in existing engineering practices is shown in Figure 6 The specific analysis is as follows

[0093] Water level difference at the gate head: The dynamic water opening and closing force of the triangular gate is mainly related to the width of the gate chamber, the water depth of the channel and the water level difference at the gate head. Based on the engineering practice experience, if the minimum water level difference at the gate head within the navigable water level range is taken as the critical condition for safe opening and closing of the gate, the water level difference control standard at the gate head can be classified according to the width of the gate chamber. Under the common gate chamber widths b = 23m, 16m, and 12m, the recommended water level difference control standards at the gate head are Δh lim =0.30m, 0.24m, 0.20m.

[0094] Lock chamber flow rate: The lock chamber flow rate is judged by referring to the control standard of the pilot channel gate section, and the influence of the lock chamber section coefficient must be considered. The lock chamber flow rate control standard can be classified according to the lock grade. Combined with the relevant provisions of the current specifications, for Class III and Class IV locks, the recommended lock chamber flow rate control standard is v wlim =1.6m / s, for Class V ship lock, the recommended chamber flow velocity control standard is v wlim =1.4m / s, which are respectively equivalent to 0.80 times and 0.70 times the flow velocity control standard of the pilot channel entrance section.

[0095] Ship speed: The speed of ships in the lock chamber should be maintained within a safe range, and the ship speed control standard can be classified according to the lock grade. Regarding the minimum ship speed, referring to the regulation that the speed of the fleet sailing between Han and Chongqing to the other side shall not be less than 1.11m / s after the completion of the Three Gorges Dam on the Yangtze River, considering the scale of the lock chamber, it is appropriately relaxed, and it is recommended that the ship speed to the other side of the lock chamber should not be less than 1.0m / s. Regarding the maximum ship speed, considering that the lock mode reduces many control links of the lock compared to the conventional mode, the speed of ships passing through the lock can be slightly faster than that of ships entering and exiting the lock. Referring to the current industry specifications and the Three Gorges Lock and Gezhouba Lock dispatching regulations that the ship's entry speed should not be greater than 1.0m / s and the exit speed should not be greater than 1.4m / s, and combined with the practical experience of the lock engineering, for Class III, IV, and V locks, the recommended ship speed control standards are v, s, and t, respectively. slim =1.6m / s, 1.5m / s, 1.4m / s.

[0096] Ship spacing: Ship type, size, speed and load are important factors in determining the longitudinal safety distance between inland ships. Generally speaking, the larger the ship, the faster the speed and the smaller the load, the greater the required safety distance. Based on the practical experience of lock engineering, it is recommended to use 1 times the ship length for fleets and heavy-loaded ships, while for unloaded ships, due to their higher "flexibility", it is recommended to use 2 times the ship length from a safety perspective.

[0097] The gate safety control index system and its evaluation criteria are shown in Figure 7 .

[0098] S3. Set the gate operation conditions including gate opening conditions, ship navigation conditions and gate closing conditions. The setting method of each operation condition is as follows:

[0099] Gate opening condition: when the water level difference at the gate head satisfies Δh≤Δh lim When the gate is opened, the vehicle can be released;

[0100] Ship navigation conditions: During the lock process, ships should navigate in the lock chamber at a safe speed and maintain an appropriate safety distance, i.e. v s ≤v slim , ΔL≥ΔL lim ;

[0101] Gate closing condition: When the flow rate in the gate chamber reaches the limit value, that is, v w =v wlim , the gate needs to be closed to end the gate passage.

[0102] The method for setting the operating conditions of the ship lock is shown in Figure 8The gate opening condition mainly considers the gate opening safety, which is controlled by the gate head water level difference index. When the gate head water level difference satisfies Δh≤Δh lim After that, the gate can be opened to release the ship. Considering the safety of ship passing through the lock and the navigation efficiency, the ship should sail in the lock chamber at the recommended speed and maintain an appropriate safety distance, that is, v s ≤v slim , ΔL≥ΔL lim During the gate opening process, strict attention should be paid to the flow velocity changes in the gate chamber. When the flow velocity in the gate chamber reaches v wlim When the gate is closed, the gate is closed to end the passage.

[0103] S4. Based on the ship lock grade, lock chamber width and ship types of the actual project, the ship lock safety assessment standard and lock operation conditions are applied to obtain the ship lock safety assessment result.

[0104] Specific implementation cases

[0105] In a typical canal hub project, the hub building consists of a water intake gate, a regulating gate and a ship lock, and its main functions are water delivery, flood discharge and navigation. According to the dispatching principle, when there is no water supply demand in the water delivery section below the hub, the regulating gate is opened, and the water levels on both sides of the ship lock are level, which meets the conditions for the lock to be opened. The design level of the ship lock is level III, and the representative ship types are 1000-ton cargo ships (58m in length) and a 2×1000-ton fleet. The effective size of the ship lock is 240m×23m×5.2m (length×width×sill depth). The lock operation conditions are set as follows:

[0106] The lock chamber width determines the conditions for opening the lock. The lock chamber width is 23m, and the corresponding limit value of the water level difference at the lock head is Δh lim =0.30m, when the water level difference at the gate head satisfies Δh≤0.30m, the gate can be opened to release traffic;

[0107] The navigation conditions for ships are determined according to the lock grade and the type of ships passing through the lock. The design grade of the lock is III, and the corresponding ship speed limit is v slim =1.6m / s; the representative ship type is a 1000-ton cargo ship (58m in length) and a 2×1000-ton fleet. For fleets and heavy-loaded ships, the limit value of the distance between ships is ΔL lim =58m, for an unladen ship, the limit value of the distance between ships is ΔL lim =116m. Under the lock-through operation mode, the speed of ships passing through the lock should not exceed 1.6m / s, the distance between unladen ships should not be less than 58m, and the distance between fleets and heavily laden ships should not be less than 116m.

[0108] The closing conditions are determined according to the ship lock grade. The chamber velocity limit for the Class III ship lock is v wlim=1.6m / s. When the flow velocity in the gate chamber reaches 1.6m / s, the gate should be closed in time to end the gate opening.

[0109] In summary, the ship lock operation conditions of the application example are listed in Table 1.

[0110] Table 1 Application example lock operation conditions

[0111]

[0112]

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for judging safe passage of ships through a lock based on lock opening and closing and ship navigation conditions, characterized in that: The method comprises the following steps: S1. Establish the water level difference Δh at the gate head and the water flow velocity v in the gate chamber. w , ship speed v s and the lock safety control index system of ship spacing ΔL; S2. According to the navigable water level range and channel conditions, set the limit values ​​of various indicators as the safety evaluation criteria for lock opening; S3. Setting the gate operation conditions including gate opening conditions, ship navigation conditions and gate closing conditions; S4. Based on the ship lock grade, lock chamber width and ship types of the actual project, the ship lock safety assessment standard and lock operation conditions are applied to obtain the ship lock safety assessment result.

2. The method for judging safe passage of ships through the lock based on the lock opening and closing and the ship navigation conditions according to claim 1 is characterized in that: The gate safety control index system includes gate opening and closing safety control index and ship navigation safety control index. The gate is a triangular gate. The gate opening and closing safety control index is the gate head water level difference Δh at the beginning and end of the gate opening. The ship navigation safety control index is the gate chamber water flow velocity v during the gate opening process. w , ship speed v s , ship spacing ΔL.

3. The method for judging safe passage of a ship based on gate opening and closing and ship navigation conditions according to claim 2 is characterized in that: In step S2, the limit value Δh of the water level difference at the gate head is determined according to the gate chamber width classification. lim : When the lock chamber width is 23m, Δh lim =0.30m, when the lock chamber width is 16m, Δh lim =0.24m, when the lock chamber width is 12m, Δh lim =0.20m.

4. The method for judging safe passage of a ship through a lock based on lock opening and closing and ship navigation conditions according to claim 3, characterized in that: In step S2, the limit values ​​v of the water flow velocity in the lock chamber and the ship speed are determined according to the classification of the lock level. slim : When the lock level is Class III and Class IV, v slim =1.6m / s, when the lock level is V-level lock, v slim =1.4m / s; when the ship lock level is Class III ship lock, v s ≤1.6m / s, when the lock level is IV, v s ≤1.5m / s, when the lock grade is V-class lock, v slim =1.4m / s; According to the classification of ship types, the limit value ΔL of the ship spacing is established lim , when the ship type is fleet and heavy-load ship, ΔL lim =1 times the ship length, when the ship type is an empty ship, ΔL lim = 2 times the length of the ship.

5. The method for judging safe passage of ships through the lock based on the lock opening and closing and the navigation conditions of the ships according to claim 4, characterized in that: The gate opening condition is Δh≤Δh lim ; The ship navigation condition is v s ≤v slim And ΔL ≥ ΔL lim The gate closing condition is v w =v wlim .

6. The method for judging safe passage of a ship through a lock based on lock opening and closing and ship navigation conditions according to claim 2, characterized in that: The method for determining the gate opening and closing safety control index is: The opening and closing force of the triangular gate is calculated as follows: Where: T is the opening and closing force of the triangular gate, in kN; K is the safety factor; ∑M is the total resistance moment of opening or closing the triangular gate, in kN; R is the arm from the traction force to the rotation center, in m; Total resistance moment ∑M=M1+M2+M3+M4+M5, where M1 is the friction resistance moment of the top pivot and the bottom pivot; M2 is the friction resistance moment of the bottom water stop; the middle and side of M3 are the friction resistance moment of the surface water stop; M4 is the eccentric resistance moment of the water pressure caused by the asymmetric horn; and M5 is the water flow resistance moment; When the gate is opened and closed, the middle and side water stops are instantly disconnected or contacted, and M3 is negligible; assuming that the triangular gate horns are arranged symmetrically, then M4 = 0; M1, M2, and M5 are related to the gate structure layout, the gate deadweight, and the initial water flow state when the gate is opened and closed; the gate opening and closing force is expressed as a function of the following water flow force: T=f(p2) (2) The water flow force is calculated as follows: Where: p2 is the water flow force; the unit is kN; C w is the water flow resistance coefficient; ρ is the water density, in m 3 / s; v is the water flow velocity in the triangular gate gap section, in m / s; A is the projected area of ​​the calculation component on the plane perpendicular to the flow direction, in m 2 ; A = bh; b is the width of the lock chamber, in m; h is the water depth of the channel, in meters; During the opening and closing process of the triangular gate, the flow velocity of the gate gap section is related to the water level difference on both sides of the gate. Ignoring the influence of the gate gap section contraction and the gate opening and closing inertia, the flow velocity of the gate gap section is expressed as a function of the water level difference on both sides of the gate. Let Δh be the gate head water level difference at the beginning and end of the gate opening, then: The calculation formula of water flow force is as follows: p2=C w ρgbΔhh (4) The calculation formula of the gate opening and closing force is obtained from equations (2) and (4) as follows: T=f(b·Δh·h) (4) When the reduction coefficient of the rated capacity of the gate hoist is determined, for the ship lock project with a determined lock chamber width, there is a critical water level difference on both sides of the gate under different channel water depths. Considering the convenience of scheduling and management, the water level difference at the gate head at the beginning and end of the gate opening is used as the main control indicator for the safety of gate opening and closing.

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