Sweeping spraying pump operation system, operation method and ship

Abstract

The invention discloses a sweeping spray pump operation system, an operation method and a ship, and the system comprises a sweeping spray pump which is arranged at the bottom of a liquid cargo tank. The spraying main pipeline is arranged outside the top of the liquid cargo tank and connected with the sweeping spraying pump through a sweeping pipeline, a pipeline connected to the top of the liquid cargo tank is arranged on the spraying main pipeline, a cargo tank spraying opening is formed in the tail end of the pipeline, and a control valve sweeping pipeline is arranged between the cargo tank spraying opening and the spraying main pipeline. And a sweeping spray pump discharge valve, an outlet check valve and a header pipe isolating valve are sequentially arranged from top to bottom. One end of the return pipeline is communicated between the outlet check valve and the main pipe isolating valve, the other end of the return pipeline is communicated with the bottom of the liquid cargo tank, and a return valve is arranged on the return pipeline. According to the method, the smooth starting process of the domestic sweeping spray pump can be ensured, the operation flow interval of the domestic sweeping spray pump is reasonably expanded, the adaptation degree of the domestic sweeping spray pump, deep cooling equipment and a ship power system is enhanced, and the comprehensive availability, operation stability and comprehensive working performance of the equipment are improved.

Description

Technical Field

[0001] The present invention belongs to the field of low-temperature equipment operation, gas trial technology and ship operation of LNG transport ships and bunkering ships, and specifically relates to a stripping spray pump operating system, operating method and ship that matches the characteristics of a domestic stripping spray pump and is in the operating environment of domestic LNG ship equipment. Background Art

[0002] On liquefied natural gas (LNG) carriers and bunkering vessels, cryogenic submersible stripping spray pumps are key equipment, and their performance and reliability have a significant impact on the overall operation of the ship. However, for a long time, LNG ship cryogenic submersible pumps have mainly relied on imported products from abroad, with high technical barriers, which has largely restricted the development of core cryogenic equipment such as cryogenic submersible pumps for LNG carriers in my country. In recent years, with the continuous advancement of domestic cryogenic submersible pump technology, a domestic brand cryogenic submersible pump was installed on a 14,000 cubic meter bunkering vessel built by Hudong-Zhonghua for the first time, and test sea trials, commissioning and verification were carried out. However, with existing technologies, there are significant differences between the equipment performance of domestic stripping spray pumps and the domestically developed environment in which they are located, and the traditional imported operation and operation technology environment, resulting in many difficulties in actual ship commissioning and operation. The main problems include:

[0003] 1. The starting current of the domestically produced stripping spray pump is as high as 518A, which is 2.94 times the average starting current of the same type of imported stripping spray pump (about 176A). The impact on the LNG ship's cargo system power grid at the moment of startup is significantly greater, causing great pressure on the ship's power management system.

[0004] 2. The operating flow range of domestically produced stripping spray pumps is relatively small, which limits the operating flexibility of the stripping spray pumps and affects the matching degree of the stripping spray pumps with their liquid supply targets, that is, the operating range of domestically produced cryogenic systems.

[0005] 3. The operating performance of domestic stripping spray pumps is unstable under low liquid level conditions. It is necessary to comprehensively consider that the operating environment of the stripping spray pump is at the bottom of the independently developed B-type cargo hold. There are many reinforced structures in this area, and the height of the reinforced structures is more than 10 times higher than the low operating liquid level height of the stripping spray pump. Such a high multi-block structure will lead to the restriction of the bottom flow of LNG liquid, affecting the stability of the domestic stripping spray pump in the low liquid level operating environment.

[0006] Since the first domestically produced stripping spray pump has characteristics and features that are different from imported equipment, if it is operated and run in the traditional way, its main performance indicators and reliability will lag significantly behind those of imported equipment, which will seriously affect the safe and stable operation of the LNG ship's low-temperature system and corresponding equipment, as well as the user experience.

[0007] Therefore, there is an urgent need for an operation method of a stripping spray pump that matches the characteristics of a domestic stripping spray pump and is in the operating environment of domestic LNG ship equipment. Summary of the Invention

[0008] In order to solve the above technical problems, the present invention provides a stripping spray pump operating system, operating method and ship that match the characteristics of domestic stripping spray pumps and are in the operating environment of domestic LNG ship equipment. It can ensure the smooth startup process of the domestic stripping spray pump, reasonably expand the operating flow range of the domestic stripping spray pump, and enhance the compatibility of the domestic stripping spray pump with cryogenic equipment and ship power systems, improve the comprehensive availability, operating stability and comprehensive working performance of the equipment, and contribute to the application and promotion of domestic low-temperature core equipment.

[0009] The object of the present invention is achieved through the following technical solutions: a tank stripping spray pump operating system, comprising:

[0010] The stripping spray pump is installed at the bottom of the liquid cargo tank.

[0011] The main spray pipeline is arranged outside the top of the liquid cargo tank and is connected to the stripping spray pump through the stripping pipeline. The main spray pipeline is provided with a pipeline connected to the top of the liquid cargo tank, and a cargo hold spray port is provided at the end of the pipeline. A control valve is provided between the cargo hold spray port and the main spray pipeline.

[0012] The stripping pipeline is provided with a stripping spray pump discharge valve, an outlet check valve and a main pipe isolation valve from top to bottom.

[0013] The reflux pipeline has one end connected between the outlet check valve and the main pipe isolation valve, and the other end connected to the bottom of the liquid cargo tank. A reflux valve is provided on the reflux pipeline.

[0014] Preferably, the stripping spray pump operating system further comprises:

[0015] The standby stripping spray pump is installed at the bottom of the liquid cargo tank.

[0016] The spare tank stripping pipeline connects the main spray pipeline and the spare tank stripping spray pump. From top to bottom, a spare tank stripping spray pump discharge valve, a spare outlet check valve and a spare main pipe isolation valve are provided.

[0017] The standby reflux line has one end connected between the standby outlet check valve and the standby main pipe isolation valve, and the other end connected to the bottom of the liquid cargo tank. A standby reflux valve is provided on the standby reflux line.

[0018] In addition to providing a tank stripping spray pump operating system, the present invention further provides an operating method of the above-mentioned tank stripping spray pump operating system, which specifically includes the following steps:

[0019] Step 1: Adjust the parameters of the built-in boost spring of the outlet check valve to achieve the matching flow cross-section under the corresponding pressure;

[0020] Step 2: Check whether the tank spray pump pipeline is available and adjust the cargo hold spray valve to a suitable opening;

[0021] Step 3: Adjust the check valve at the outlet of the stripping spray pump to the appropriate opening;

[0022] Step 4: Start the tank stripping spray pump and observe the combing flow;

[0023] Step 5: gradually close the comb flow line at a uniform rate;

[0024] Step 6: Adjust the operating current of the stripping spray pump distribution board according to the current displayed on the IAS;

[0025] Step 7: Stably control the opening of the return valve to control the pressure of the liquid supplied to the external side of the stripping spray pipe;

[0026] Step 8: Adjust the critical interval rate setting of the tank stripping spray pump outlet check valve;

[0027] Step 9: After the tank stripping spray pump runs stably, gradually adjust and widen the low current setting of the tank stripping spray pump;

[0028] Step 10: Expand the operating range of the stripping spray pump so that the stripping spray pump and the domestic cryogenic device can operate in coordination;

[0029] Step 11: Adjust the discharge valve of the stripping spray pump to achieve a stable and reliable supply to the system.

[0030] Preferably, in step 1, the parameters of the built-in boost spring of the outlet check valve are adjusted so that when the liquid supply LNG fluid is half of the rated outlet pressure of the stripping spray pump, the flow rate corresponding to the valve core height can reach more than 75% of the flow rate of the outlet pipeline of the stripping spray pump.

[0031] Preferably, in step 4, the opening degree of the discharge valve of the stripping spray pump is 52% to 63% of its discharge flow rate.

[0032] Preferably, in step 5, the return line or cargo hold spray port is closed at a rate of 5% every 10 seconds.

[0033] Preferably, in step 8, the critical interval rate of the tank stripping spray pump outlet check valve is set as: the tank stripping spray pump is within the range of 101% to 106% of the original low current setting value.

[0034] Preferably, in step 10, after the tank stripping spray pump has been running stably for 15 minutes, the low current setting of the tank stripping spray pump is gradually adjusted to 93% of the original setting.

[0035] Preferably, in step 11, the discharge valve of the stripping spray pump is adjusted so that its supply flow rate is not less than 108% of the actual required flow rate of the cryogenic device.

[0036] The present invention also provides a ship, which is provided with the above-mentioned tank stripping spraying system.

[0037] Compared with the prior art, the present invention has the following advantages:

[0038] The present invention provides an operating system, operating method and ship for a stripping spray pump, which improves the performance of domestic equipment, enhances system stability and expands the equipment operating range: by optimizing the operating method of the stripping spray pump, the performance of domestic stripping spray pumps is significantly improved, making it closer to or reaching the performance standards of imported equipment; the present invention effectively reduces the impact on the LNG ship's cargo system power grid by precisely controlling the starting current and operating flow of the stripping spray pump, and enhances the stability of the ship's power management system; by adjusting the opening of the discharge valve of the stripping spray pump, the operating flow range of the pump is reasonably expanded, and the operating flexibility and adaptability of the stripping spray pump are improved.

[0039] The present invention provides a tank stripping spray pump operating system, operating method and ship, which improve the safety of domestic equipment and promote the further localization of LNG ship equipment: the present invention provides an operating method with more stable operating performance under low liquid level conditions, reduces the safety risks caused by improper operation, and promotes the localization of LNG ship low-temperature core equipment by resolving the performance differences between domestic tank stripping spray pumps and imported equipment, which helps to break down foreign technical barriers.

[0040] The present invention provides a tank stripping spray pump operating system, operating method and ship, which reduce the operating costs of ships using domestically produced related equipment and improve the user experience: the optimized operating process reduces the additional maintenance and operating costs caused by equipment failure or unstable performance, and improves the user experience when using LNG ships for gas trials by improving the stability and reliability of equipment operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a flow chart of an operating method of a stripping spray pump according to an embodiment of the present invention;

[0042] Figure 2 Schematic diagram of the tank stripping spray pump system in an embodiment of the present invention;

[0043] Figure 3 This is a diagram showing the actual application of pipeline combing using a spare stripping spray pump in an embodiment of the present invention;

[0044] Figure 4 This is a diagram showing the actual application of cargo hold spray pipe combing in an embodiment of the present invention.

[0045] In the figure, 1 is the stripping spray pump; 2 is the liquid cargo tank; 3 is the spray main pipe; 4 is the cargo hold spray port; 5 is the stripping spray pump discharge valve; 6 is the outlet check valve; 7 is the main pipe isolation valve; 8 is the return valve; 9 is the standby stripping spray pump; 10 is the standby stripping spray pump discharge valve; 11 is the standby outlet check valve; 12 is the standby main pipe isolation valve; 13 is the standby return valve; 14 is the cargo hold spray main control valve; and 15 is the cargo hold spray manual valve. DETAILED DESCRIPTION

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0047] In order to solve the above problems, the technical solution of the present invention provides a tank stripping spray pump operating system, comprising:

[0048] A stripping spray pump 1 is provided at the bottom of the cargo tank 2;

[0049] The main spray pipeline 3 is arranged outside the top of the liquid cargo tank 2 and is connected to the stripping spray pump 1 through a stripping pipeline. The main spray pipeline 2 is provided with a pipeline connected to the top of the liquid cargo tank 2, and a cargo hold spray port 4 is provided at the end of the pipeline. Control valves including a cargo hold spray main control valve 14 and a cargo hold spray manual valve 15 are provided between the cargo hold spray port 4 and the main spray pipeline 3.

[0050] The stripping pipeline is provided with a stripping spray pump discharge valve 5, an outlet check valve 6 and a main pipe isolation valve 7 from top to bottom;

[0051] The reflux pipeline has one end connected between the outlet check valve 6 and the main pipe isolation valve 7, and the other end connected to the bottom of the liquid cargo tank 2. A reflux valve 8 is provided on the reflux pipeline.

[0052] like Figure 1 As shown, in one embodiment of the present invention, the stripping spray pump operating system further includes:

[0053] A standby stripping spray pump 9 is provided at the bottom of the cargo tank 2;

[0054] The standby stripping pipeline is connected to the spray main pipeline 2 and the standby stripping spray pump 9. From top to bottom, a standby stripping spray pump discharge valve 10, a standby outlet check valve 11 and a standby main pipe isolation valve 12 are provided in sequence;

[0055] One end of the standby reflux pipeline is connected between the standby outlet check valve 11 and the standby main pipe isolation valve 12, and the other end is connected to the bottom of the liquid cargo tank 2. A standby reflux valve 13 is provided on the standby reflux pipeline.

[0056] The application provides a cabin spraying pump operation system and a method for operating the same.

[0057] Step 1, adjust the built-in booster spring parameter of the outlet check valve to match the flow cross section at the corresponding pressure;

[0058] Step 2, check whether the cabin spraying pump pipeline is available, and adjust the cabin spraying valve to a suitable opening degree;

[0059] Step 3, adjust the outlet check valve of the cabin spraying pump to a suitable opening degree;

[0060] Step 4, start the cabin spraying pump and observe the combing flow;

[0061] Step 5, gradually close the combing pipeline at a uniform rate;

[0062] Step 6, adjust the operating current of the cabin spraying pump distribution board according to the IAS display current;

[0063] Step 7, stably control the pressure of the cabin spraying pipeline to the external liquid supply by adjusting the opening degree of the backflow valve;

[0064] Step 8, adjust the key interval rate setting of the outlet check valve of the cabin spraying pump;

[0065] Step 9, after the cabin spraying pump is stably operated, gradually adjust the low current setting of the cabin spraying pump to be widened;

[0066] Step 10, expand the operation interval of the cabin spraying pump to make the cabin spraying pump and the domestic cryogenic device operate cooperatively;

[0067] Step 11, adjust the discharge valve of the cabin spraying pump to reach a stable and reliable supply amount of the system.

[0068] As shown in the drawings, Figure 2 in one specific embodiment of the application, the method for operating the cabin spraying system with a standby pipeline comprises the following steps:

[0069] Step 1: disassemble, inspect and adjust the built-in booster spring parameter of the outlet check valve of the cabin spraying pump 1# to make the LNG fluid supplied at half of the rated outlet pressure of the cabin spraying pump continuously open the valve core height corresponding to the flow rate to reach more than 75% of the flow rate of the cabin spraying pump outlet pipeline;

[0070] Step 2-1': as shown in the drawings, Figure 3 before starting the domestic cabin spraying pump, when the standby cabin spraying pump and the corresponding standby pipeline are designed and configured, the valve state and instrument connection of the standby pump backflow pipeline are checked to ensure that the pipeline of the cabin spraying pump and the standby pipeline circulation are in an available state.

[0071] Step 2-2': As shown in Figure 4 Before starting the domestic cabin spray pump, when there is no standby pump and corresponding pipeline, check the valve state and instrument connection of the cabin spray total control valve and the cabin spray manual valve, and ensure that the pipeline of the cabin spray pump to the cabin spray pipeline is in a usable state.

[0072] Step 3-1': As shown in Figure 3 Open the standby total pipe isolation valve and the standby backflow valve pipeline, adjust the opening of the standby backflow valve to more than 85% of the flow rate of the cabin spray pump discharge pipeline diameter according to the CV value curve of the valve selection, so as to borrow its channel to start the cabin spray pump during the starting stage.

[0073] Step 3-2': As shown in Figure 4 Open the cabin spray port, adjust the opening of the cabin spray total control valve to more than 75% of the flow rate of the cabin spray pump discharge pipeline diameter according to the CV value curve of the valve selection, so as to borrow its channel to start the cabin spray pump during the starting stage.

[0074] Step 4: Open the discharge valve of the domestic cabin spray pump, and the set opening can be calculated and checked according to the known corresponding starting parameters of the imported cabin spray pump. Since the starting current range is 29%-39% of the domestic cabin spray pump, and the flow rate is positively related to the square of the valve opening, the discharge valve opening setting of the domestic cabin spray pump needs to be 52%-63% of the discharge flow rate according to the corresponding CV value curve of the domestic low-temperature valve, and the main road backflow valve is opened with an opening of 100%;

[0075] Step 5: Start the domestic cabin spray pump, and the starting current and output flow rate of the cabin spray pump during the starting stage will be higher. Observe the running state and current change to verify whether the additional flow rate corresponding to the opening of the comb valve is appropriate.

[0076] Step 6: After the pump is stably running, close the standby pump backflow pipeline or close the cabin spray port at a rate of 5% per 10 seconds until it is completely closed, and restore the pipeline and current state of the cabin spray pump to normal operation.

[0077] Step 7: Monitor the matching of the distribution board and the cabin spray pump during actual operation, and make parameter adjustment and optimization as needed.

[0078] Step 8: Control the pressure of the cabin spray pipeline to the outside liquid supply with the backflow valve opening, and keep the stable setting.

[0079] Step 9: Ensure the pump is operating within its normal operating range. Calibrate the switchboard current display and the IAS to ensure the local display is consistent with the IAS system display. Adjust the critical range rate setting of the stripping spray pump outlet valve to ensure that the stripping spray pump is within the original low current setting range of 101% to 106%, and the outlet valve closing rate does not exceed 1% per 5 seconds.

[0080] Step 10: When the above 9 steps have been run stably for more than 15 minutes, the low current setting of the stripping spray pump can be gradually adjusted to 93% of the original setting to ensure that it can still operate stably at a small flow rate in the bottom area of ​​the type B tank.

[0081] Step 11: After expanding the operating range of the stripping spray pump, its coordinated operation with the domestic cryogenic device can be completed. When the domestic cryogenic device is started, ensure that the stripping spray pump is in the self-circulating state in the cabin, monitor the pre-cooling cycle process of the cryogenic device, and ensure that the refrigerant temperature reaches the set requirements;

[0082] Step 12: After the refrigerant cycle is completed, adjust the discharge valve of the stripping spray pump so that its supply flow reaches more than 108% of the actual demand flow of the cryogenic device, and control the redundant return flow through the 1# return valve to improve the overall liquid supply system and equipment operation stability.

[0083] The technical solution of the present invention further provides a ship, which is provided with the above-mentioned tank stripping spray system.

[0084] The present invention is aimed at the system operating environment of the stripping spray pump for domestic liquefied natural gas (LNG) ships and bunkering ships, which is mainly based on domestic LNG ship equipment, and aims to solve the performance characteristics of domestic stripping spray pumps in terms of large starting current, large flow rate at the moment of starting, and small operating flow range. Through the method of the present invention, the starting process is optimized, the operating flow range is expanded, and the compatibility with deep-cold equipment and ship power systems is enhanced, so that the comprehensive availability, operating stability, and comprehensive working performance of the equipment are stronger, and the user experience of the first set of domestic core cryogenic equipment is improved, thereby ensuring the operational safety, operating efficiency and operating experience of domestic core cryogenic equipment on LNG ships.

[0085] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A tank stripping spray pump operating system, characterized by: The system comprises: A tank stripping spray pump (1) is arranged at the bottom of the liquid cargo tank (2); A main spray pipeline (3) is arranged outside the top of the liquid cargo tank (2) and is connected to the tank stripping spray pump (1) through a tank stripping pipeline. The main spray pipeline (2) is provided with a pipeline connected to the top of the liquid cargo tank (2). A cargo tank spray port (4) is provided at the end of the pipeline. A control valve is provided between the cargo tank spray port (4) and the main spray pipeline (3). The stripping pipeline is provided with a stripping spray pump discharge valve (5), an outlet check valve (6) and a main pipe isolation valve (7) in sequence from top to bottom; A reflux pipeline has one end connected between the outlet check valve (6) and the main pipe isolation valve (7), and the other end connected to the bottom of the liquid cargo tank (2). A reflux valve (8) is provided on the reflux pipeline.

2. A tank stripping spray pump operating system according to claim 1, characterized in that: The stripping spray pump operating system also includes: a standby tank stripping spray pump (9), arranged at the bottom of the liquid cargo tank (2); A spare tank stripping pipeline is connected to the spray main pipeline (2) and the spare tank stripping spray pump (9), and is provided with a spare tank stripping spray pump discharge valve (10), a spare outlet check valve (11) and a spare main pipe isolation valve (12) in sequence from top to bottom; A standby return line has one end connected between the standby outlet check valve (11) and the standby main pipe isolation valve (12), and the other end connected to the bottom of the liquid cargo tank (2). A standby return valve (13) is provided on the standby return line.

3. A method for operating a tank stripping spray pump operating system, characterized in that: The liquid cargo tank is stripped and sprayed using the stripping spray pump operating system according to any one of claims 1 to 2, and the method specifically comprises the following steps: Step 1: Adjust the parameters of the built-in boost spring of the outlet check valve to achieve a matching flow cross-section under the corresponding pressure; Step 2: Check whether the tank spray pump pipeline is available and adjust the cargo hold spray valve to a suitable opening; Step 3: Adjust the check valve at the outlet of the stripping spray pump to the appropriate opening; Step 4: Start the tank stripping spray pump and observe the combing flow; Step 5: gradually close the comb flow line at a uniform rate; Step 6: Adjust the operating current of the stripping spray pump distribution board according to the current displayed on the IAS; Step 7: Stably control the opening of the return valve to control the pressure of the liquid supplied to the external side of the stripping spray pipe; Step 8: Adjust the critical interval rate setting of the tank stripping spray pump outlet check valve; Step 9: After the tank stripping spray pump runs stably, gradually adjust and widen the low current setting of the tank stripping spray pump; Step 10: Expand the operating range of the stripping spray pump so that the stripping spray pump and the domestic cryogenic device can operate in coordination; Step 11: Adjust the discharge valve of the stripping spray pump to achieve a stable and reliable supply to the system.

4. The method for operating a tank stripping spray pump operating system according to claim 3, characterized in that: In step 1, the parameters of the built-in boost spring of the outlet check valve are adjusted so that the flow rate corresponding to the valve core height can continuously push open the valve core at half the rated outlet pressure of the stripping spray pump, and can reach more than 75% of the flow rate of the outlet pipeline of the stripping spray pump.

5. The method for operating a tank stripping spray pump operating system according to claim 4, characterized in that: In step 4, the opening degree of the discharge valve of the stripping spray pump is 52% to 63% of its discharge flow rate.

6. The method for operating a tank stripping spray pump operating system according to claim 5, characterized in that: In step 5, the return line or the cargo hold spray port is closed at a rate of 5% every 10 seconds.

7. The method for operating a tank stripping spray pump operating system according to claim 6, characterized in that: In step 8, the critical interval rate of the tank stripping spray pump outlet check valve is set as follows: the tank stripping spray pump is within the range of 101% to 106% of the original low current setting value.

8. The method for operating a tank stripping spray pump operating system according to claim 7, characterized in that: In step 10, after the tank stripping spray pump has been running stably for 15 minutes, the low current setting of the tank stripping spray pump is gradually adjusted to 93% of the original setting.

9. The method for operating a tank stripping spray pump operating system according to claim 8, characterized in that: In step 11, the discharge valve of the stripping spray pump is adjusted so that its supply flow rate is not less than 108% of the actual required flow rate of the cryogenic device.

10. A vessel, characterized in that: The ship is provided with the tank stripping spray system according to any one of claims 1-2.

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