Flow balance control method for seawater cooling system in ship area

Abstract

The invention belongs to the technical field of ship and ocean engineering manufacturing, and particularly relates to a ship area seawater cooling system flow balance control method which comprises the steps that all branch remote control valves are fully opened; adjusting the flow of the bypass pipeline to reach a set value; the branch flow is adjusted from large to small; if the flow of other branches or the header pipe exceeds the tolerance range when the branches are adjusted, the step S3 is repeated until the branch with the minimum flow completes flow adjustment; and when the flow of each branch is within the tolerance range, the flow is balanced, and the adjustment is finished. When the water volume of each branch of the regional seawater cooling system changes, the whole regional seawater cooling system can operate stably by automatically controlling the opening degree of the remote control valve of each branch, automatically adjusting the cooling water flow of each branch and establishing new flow balance, and the operation difficulty of personnel is greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of ship and marine engineering manufacturing, and in particular to a flow balance control method for a regional seawater cooling system of a ship. Background Art

[0002] Large marine carriers such as engineering ships, marine engineering, and luxury cruise ships are equipped with a large number of mechanical equipment of various types, and many of them require a large amount of cooling seawater to maintain normal operation. Small ships usually use a single device to set up a dedicated seawater cooling pump; while for large ships and marine engineering, due to the large number of equipment, the equipment of the whole ship is uniformly supplied with cooling seawater in different areas and centralized monitoring in different areas has become a development trend. The regional seawater cooling system uses a small number of cooling water pumps, which is conducive to ship management and reduces the weight of the ship. However, the regional seawater cooling system serves many cooling equipment, which will inevitably lead to the complexity of the cooling system.

[0003] At present, common regional seawater cooling water systems mostly use manual control measures, which leads to the following technical problems:

[0004] 1) When debugging the regional seawater cooling system, it is difficult to balance the flow of each branch and the debugging cycle is long.

[0005] 2) The cooling water network is prone to dynamic hydraulic imbalance. In the regional seawater cooling system, when a cooling water user stops operating and cuts off the cooling water supply to its branch, the flow change in the branch will affect the original system flow balance, resulting in uneven flow distribution of the entire cooling system, which cannot meet the usage needs.

[0006] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0007] The purpose of the present invention is to solve the technical problems existing in the background technology. To this end, a flow balance control method for a regional seawater cooling system of a ship is provided. Through reasonable remote control valve adjustment logic, the regional seawater cooling system can quickly and efficiently establish a new system flow balance in changing working conditions, thereby reducing the difficulty of operation for crew members.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] A method for controlling flow balance of a regional seawater cooling system of a ship, comprising the following steps:

[0010] Step S1: All branch remote control valves are fully opened;

[0011] Step S2: adjusting the bypass pipeline flow to reach a set value;

[0012] Step S3: adjusting the branch flow in descending order;

[0013] Step S4: If the flow of other branches or the main pipe exceeds the tolerance range when adjusting the branch, repeat step S3 until the branch with the minimum flow completes the flow adjustment;

[0014] Step S5: When the flow rate of each branch is within the tolerance range, the flow rate reaches a balance and the regulation ends.

[0015] The following is a technical solution further defined by the present invention. The bypass pipeline and each branch are monitored for flow in real time by a flow meter, and the flow meter is electrically connected to the controller.

[0016] The following is a technical solution further defined in the present invention: the remote control valve is configured as a remote control flow regulating valve, and the remote control valve is electrically connected to the controller.

[0017] The following is a technical solution further defined by the present invention, wherein the tolerance range of the branch flow or the main pipe flow is 0-10%.

[0018] The following is a technical solution further defined in the present invention: when adjusting the flow of the bypass pipeline, the remote control valve adjusts the opening according to an adjustment step of 1% and an adjustment cycle of 1s.

[0019] The following is a technical solution further limited by the present invention: when the actual flow rate of the branch circuit deviates from the set value by 0-10%, the remote control valve is not adjusted.

[0020] The following is a technical solution further defined by the present invention. When adjusting the branch flow, the deviation between the actual branch flow and the set value is 10-20% or -10-0%, and the remote control valve adjusts the opening according to an adjustment step of 0.5% and an adjustment cycle of 0.3s.

[0021] The following is a technical solution further defined by the present invention. When adjusting the branch flow, the deviation between the actual branch flow and the set value is 20-40% or -30--10%, and the remote control valve adjusts the opening according to an adjustment step of 1% and an adjustment cycle of 0.3s.

[0022] The following is a technical solution further defined by the present invention. When adjusting the branch flow, the deviation between the actual branch flow and the set value is above 40% or below -30%, and the remote control valve adjusts the opening according to an adjustment step of 3% and an adjustment cycle of 0.3s.

[0023] The following is a technical solution further defined in the present invention, wherein the method is used to achieve flow balance in a ship area seawater cooling system, wherein the ship area seawater cooling system comprises: a main pipeline, a bypass pipeline and a plurality of cooling branches;

[0024] The main pipeline is provided with a seawater tank, a stop valve, a centrifugal water pump, and a stop check valve in sequence;

[0025] A flow meter, a stop valve, a flow regulating valve, a pressure sensor, and two stop check valves are arranged in sequence on the bypass pipeline;

[0026] The cooling branch is provided with a static balancing valve, a flow meter, a flow regulating valve, two parallel user branches, and a stop check valve in sequence;

[0027] Among them, a static balancing valve, a cooling device, a flow meter, a pressure sensor, and a stop check valve are arranged in sequence on the user branch line.

[0028] Compared with the prior art, the present invention has the following technical effects:

[0029] The present invention designs a flow balance control method for a ship regional seawater cooling system. When the water volume of each branch of the regional seawater cooling system changes, the opening of the remote control valve of each branch is automatically controlled to automatically adjust the cooling water flow of each branch, establish a new flow balance, and make the entire regional seawater cooling system run smoothly, greatly reducing the difficulty of personnel operation.

[0030] The present invention is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a schematic diagram of the connection relationship of the ship regional seawater cooling system in the present invention;

[0033] Figure 2 It is a schematic diagram of the branch variable step length adjustment strategy in the present invention;

[0034] Figure 3 It is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0036] This embodiment uses Figure 1 Taking the ship regional seawater cooling system shown in the figure as an example, the control method of this embodiment is described.

[0037] The ship area seawater cooling system includes: a main pipeline, a bypass pipeline and three cooling branches. The main pipeline is provided with a seawater tank, a stop valve, a centrifugal water pump, and a stop check valve. The bypass pipeline is provided with a flow meter, a stop valve, a flow regulating valve, a pressure sensor, and two stop check valves. The cooling branch is provided with a static balancing valve, a flow meter, a flow regulating valve, two parallel user branches, and a stop check valve; among them, the user branch is provided with a static balancing valve, a cooling device, a flow meter, a pressure sensor, and a stop check valve.

[0038] The ship's regional seawater cooling system draws water from the seawater tank by a centrifugal water pump, and adopts two-stage flow control of the main pipeline (i.e., the main pipeline) and branch pipeline (i.e., the bypass pipeline and three cooling branches). Each user branch is equipped with a static balancing valve (or other manual control valve) to ensure that the flow distribution of each branch meets the use requirements under rated conditions. At the same time, each cooling branch is equipped with a remote control flow regulating valve and a flow meter. When the flow of the regional seawater cooling system fluctuates or the flow of the regional seawater cooling system is redistributed due to the start and stop of the cooled equipment, the remote control valve opening is controlled through the closed-loop feedback of the flow meter to establish a new balance of the system cooling water flow.

[0039] This embodiment provides a flow balance control method for a ship regional seawater cooling system, which includes: flow control points, control strategy parameters, variable step size adjustment, branch adjustment sequence, system flow balance control process and other strategic points. For example: if the flow is too large and exceeds the tolerance, the opening is reduced by calculation according to the flow deviation and the regulating valve and pipeline characteristics. If the flow is adjusted within the tolerance range, the adjustment is completed.

[0040] Flow control point: The tolerance range of branch flow or main pipe flow is 0-10%, that is, it is controlled according to the deviation of 0-10% of the total cooling water demand flow of each cooling water user in the main pipe or branch.

[0041] For the bypass pipeline, take the flow rate of the water pump outlet flowmeter as the input, subtract the total flow rate required for each branch, which is the required flow rate for the bypass. Adjust the bypass valve opening, and stop adjusting when the bypass flowmeter reaches this value.

[0042] Control strategy parameters: The parameters that affect the system stabilization time mainly include the adjustment period T and the remote control flow control valve opening adjustment step.

[0043] Variable step length adjustment: segmented processing according to flow deviation; Figure 2 As shown, specifically:

[0044] (1) Branch road:

[0045] When the deviation between the current flow rate and the design flow rate is between 0% and 10%, the remote control flow control valve will not be adjusted.

[0046] When the current flow rate deviates from the design flow rate by 10-20% or -10-0%, the remote control flow regulating valve adjusts the opening with a step length of 0.5% and a cycle of 0.3s.

[0047] When the current flow rate deviates from the design flow rate by 20 to 40% or -30 to -10%, the remote control flow regulating valve adjusts the opening with an adjustment step of 1% and an adjustment cycle of 0.3s.

[0048] When the deviation between the current flow rate and the design flow rate is above 40% or below -30%, the remote control flow control valve adjusts the opening according to the adjustment step of 3% and the adjustment cycle of 0.3s.

[0049] (2) Bypass pipeline:

[0050] The bypass line is always adjusted with a step size of 1% and a cycle of 1s.

[0051] Branch adjustment sequence: set two adjustment strategies: coarse adjustment (3%, 1%) and fine adjustment 0.5%.

[0052] When the working condition starts to switch, each branch and bypass branch starts to adjust according to the coarse adjustment strategy at the same time. When a branch reaches the flow control range, the remote control flow control valve of the branch switches to the fine adjustment mode until each branch reaches the set flow control range.

[0053] System flow balance control process: mainly includes:

[0054] The flow rate of the bypass pipeline and each branch is monitored in real time by a flow meter, and the flow meter is electrically connected to the controller.

[0055] The remote control valves of each branch are fully opened. The remote control valve is set as a remote control flow regulating valve, and the remote control valve is electrically connected to the controller.

[0056] Adjust the bypass line flow to reach the set value.

[0057] Adjust according to the branch flow rate from large to small.

[0058] If the flow rates of other branches or the main pipe exceed the tolerance range when adjusting the branch, step S3 is repeated until the branch with the minimum flow rate completes the flow adjustment.

[0059] When the flow of each branch is within the tolerance range, the flow is balanced and the regulation ends.

[0060] like Figure 3 As shown, the above process is further described:

[0061] 1. All branch remote control regulating valves are fully open.

[0062] 2. Adjust the bypass line flow to reach the set value.

[0063] 3. Adjust the branch with the maximum design flow to reach the set value; when adjusting the branch flow, it will affect the flow of other branches or the main pipe flow.

[0064] 4. Determine whether the bypass pipe flow exceeds the tolerance;

[0065] 5. If exceeded, repeat steps 2-4.

[0066] 6. If it does not exceed the limit, proceed to the next step.

[0067] 7. Adjust the branch with the second largest flow rate to reach the set value.

[0068] 8. Determine whether the flow of the regulated branch exceeds the tolerance.

[0069] 9. If exceeded, repeat steps 3-8.

[0070] 10. If it does not exceed the limit, proceed to the next step.

[0071] 11. Adjust the smaller flow branch to reach the set value.

[0072] 12. Determine whether the flow of the regulated branch exceeds the tolerance.

[0073] 13. If exceeded, repeat steps 3-12.

[0074] 14. If it does not exceed the limit, proceed to the next step.

[0075] 15. Similarly, adjust the branch flow in sequence until the branch with the minimum flow reaches the set value;

[0076] 16. Determine whether the flow of the regulated branch exceeds the tolerance.

[0077] 17. If exceeded, repeat steps 3-16.

[0078] 18. If it does not exceed the limit, it means that the system has reached flow balance and the adjustment is completed.

[0079] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, all equivalent changes made according to the shape, structure and principle of the present invention without departing from the content of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A flow balance control method for a ship regional seawater cooling system, characterized in that: The following steps are involved: Step S1: All branch remote control valves are fully opened; Step S2: adjusting the bypass pipeline flow to reach a set value; Step S3: adjusting the branch flow in descending order; Step S4: If the flow of other branches or the main pipe exceeds the tolerance range when adjusting the branch, repeat step S3 until the branch with the minimum flow completes the flow adjustment; Step S5: When the flow rate of each branch is within the tolerance range, the flow rate reaches a balance and the regulation ends.

2. A method for controlling flow balance of a ship regional seawater cooling system according to claim 1, characterized in that: The flow rate of the bypass pipeline and each branch is monitored in real time by a flow meter, and the flow meter is electrically connected to the controller.

3. A method for controlling flow balance of a ship regional seawater cooling system according to claim 1, characterized in that: The remote control valve is configured as a remote control flow regulating valve, and the remote control valve is electrically connected to the controller.

4. A method for controlling flow balance of a ship regional seawater cooling system according to claim 1, characterized in that: The tolerance range of branch flow or main pipe flow is 0 to 10%.

5. A method for controlling flow balance of a ship regional seawater cooling system according to claim 1, characterized in that: When adjusting the bypass pipeline flow, the remote control valve adjusts the opening according to the adjustment step of 1% and the adjustment cycle of 1s.

6. A method for controlling flow balance of a ship regional seawater cooling system according to claim 4, characterized in that: When the actual flow of the branch deviates from the set value by 0-10%, the remote control valve will not be adjusted.

7. A method for controlling flow balance of a ship regional seawater cooling system according to claim 4, characterized in that: When adjusting the branch flow, if the deviation between the actual branch flow and the set value is 10-20% or -10-0%, the remote control valve adjusts the opening according to the adjustment step of 0.5% and the adjustment cycle of 0.3s.

8. A method for controlling flow balance of a ship regional seawater cooling system according to claim 7, characterized in that: When adjusting the branch flow, if the actual branch flow deviates from the set value by 20 to 40% or -30 to -10%, the remote control valve adjusts the opening according to the adjustment step of 1% and the adjustment cycle of 0.3s.

9. A method for controlling flow balance of a ship regional seawater cooling system according to claim 8, characterized in that: When adjusting the branch flow, if the actual branch flow deviates from the set value by more than 40% or less than -30%, the remote control valve adjusts the opening according to the adjustment step of 3% and the adjustment cycle of 0.3s.

10. A method for controlling flow balance of a ship regional seawater cooling system according to claim 1, characterized in that: The method is used to achieve flow balance of a ship area seawater cooling system, wherein the ship area seawater cooling system comprises: a main pipeline, a bypass pipeline and a plurality of cooling branches; The main pipeline is provided with a seawater tank, a stop valve, a centrifugal water pump, and a stop check valve in sequence; A flow meter, a stop valve, a flow regulating valve, a pressure sensor, and two stop check valves are arranged in sequence on the bypass pipeline; The cooling branch is provided with a static balancing valve, a flow meter, a flow regulating valve, two parallel user branches, and a stop check valve in sequence; Among them, a static balancing valve, a cooling device, a flow meter, a pressure sensor, and a stop check valve are arranged in sequence on the user branch line.

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