Electrolytic antifouling device for ship seawater pipeline system

Abstract

The invention belongs to the technical field of electrolytic antifouling, and particularly relates to an electrolytic antifouling device for a ship seawater pipeline system, which is based on a method for diluting and dissolving hydrogen in seawater, further optimizes composition, and simplifies a main body structure into three parts, namely a seawater pretreatment unit, an electrolysis unit and an electric control unit, the main body structure of the electrolysis unit is an electrolysis cell set formed by connecting a plurality of branch pipe type electrolysis cells in parallel through a water path, the occupied space is effectively reduced, seawater dilution hydrogen is adopted to replace air dilution hydrogen, storage-free direct discharge of electrolyte is achieved, and the electrolysis antifouling device for the ship pipeline system is miniaturized and does not generate free hydrogen. The device can effectively slow down the scaling rate of CaCO3, Mg (OH) 2 and other calcium and magnesium deposition layers generated by the cathode when the electrolysis unit electrolyzes seawater, further effectively reduces the pickling frequency of the electrolytic cell, improves the single continuous operation time, directly dissolves the seawater electrolysis byproduct hydrogen in cooling seawater and discharges the hydrogen out of an outboard pipeline, and eliminates the risk of hydrogen gathering, precipitation and leakage.

Description

Technical field:

[0001] The present invention belongs to the technical field of electrolytic antifouling, and specifically relates to an electrolytic antifouling device for a ship seawater pipeline system, which can solve the problems of large space occupation of hydrogen removal units and hydrogen exhaust pipelines and difficulty in hydrogen discharge. Background technology:

[0002] Marine biofouling is a problem that humans have been facing since they started engaging in maritime activities, and it is also one of the key issues that must be resolved when ships are serving in the marine environment. The seawater piping system is an important part of the ship's power system and auxiliary system. The reliable operation of the seawater piping system plays an important role in the safety of ship navigation. Once the ship's seawater piping system is significantly fouled, the effective diameter of the pipeline will be reduced, the flow resistance will increase, and the cooling effect will be reduced. When the blockage is serious, it may cause unplanned downtime, suspension of navigation, increase maintenance time and costs, and even lead to safety accidents. Based on this, corresponding anti-fouling measures must be taken.

[0003] Electrolysis of seawater antifouling technology uses special electrodes to electrolyze seawater to generate highly oxidizing ClO - It can inhibit the growth of marine organisms, thereby achieving the purpose of anti-fouling. It is a commonly used ship anti-fouling technology. The electrodes used in it have a long life, low maintenance costs, can achieve continuous operation, and can meet the anti-fouling needs of large water volumes and multiple users. It is widely used in power plant cooling water and ship ballast water anti-fouling. However, its electrolysis by-product is hydrogen generated on the cathode surface. If appropriate measures are not taken to eliminate hydrogen, it may cause hydrogen to accumulate in the ship, and explosions and other safety accidents are very likely to occur within a certain concentration range.

[0004] At present, the dehydrogenation method of electrolytic seawater anti-fouling devices generally adopts the air dilution hydrogen discharge method, which first separates hydrogen from the electrolyzed seawater, and then blows in a large amount of air to dilute the hydrogen concentration to a safe range before discharging it. For example, Chinese patent 201220135340.1 discloses an electrolytic seawater anti-fouling device for a large seawater cooling system, in which a seawater booster pump for conveying cooling seawater and a cooling water pump for the cooling system are respectively connected to the seawater, one end of the seawater booster pump is connected to the seawater, and the other end is connected to the electrolytic cell via a disc filter, and the output of the electrolytic cell is connected to a liquid storage tank with a dehydrogenation fan on one side, and the liquid storage tank is connected to the water intake of the cooling water pump of the cooling system in the seawater via a dosing pump, and the pipeline between the disc filter and the liquid storage tank A pickling tank and a pickling pump are installed for removing calcium and magnesium scales in the electrolytic cell. The pickling tank is also connected to a neutralization tank and a neutralization pump for neutralizing the discharged acid and cleaning the pickling tank. The electrolytic cell is provided with direct current by a rectifier transformer connected thereto. The lower part of the cooling water pump is connected to a dirt screen for filtering. The electrolytic cell is composed of a single cell connected in series. The anode of the electrolytic cell is a titanium substrate coated with a platinum, iridium and ruthenium composite material layer. The cathode of the electrolytic cell is a titanium substrate coated with a nickel alloy material layer. The dosing pump includes a continuous dosing pump and an impact dosing pump connected in parallel. Chinese patent 201120545099.5 discloses a chlorine-making device for electrolyzing seawater in a wind power desalination system. The wind power desalination system includes a wind power system and a desalination system, wherein the wind power system provides power for the desalination system, and the water inlet pipe of the desalination system is connected with the chlorine-making device for electrolyzing seawater. The chlorine-making device for electrolyzing seawater includes: a pre-filter, a booster pump, a post-filter, an electrolytic cell, a sodium hypochlorite storage tank and an injection pump connected in sequence through a pressure pipeline, the sodium hypochlorite storage tank is provided with an air blast port and a hydrogen exhaust port, and an air blast port is provided with an air blast port. The outlet of the injection pump is connected to the water inlet pipe of the seawater desalination system; the transformer, rectifier and low-voltage power distribution device are connected in sequence between the output end of the wind power system and the electrolytic seawater chlorine production device through busbars and cables. The pre-filter and post-filter both adopt a filter structure. The anode of the electrolytic cell adopts a titanium-coated precious metal oxide-coated anode, and the cathode of the electrolytic cell adopts a material resistant to corrosion by sodium hypochlorite solution. The materials resistant to corrosion by sodium hypochlorite solution include titanium, titanium alloy or Hastelloy. The blower is an explosion-proof motor. Each wind power seawater desalination system is equipped with a set of electrolytic seawater chlorine production device. Both use the air dilution hydrogen discharge method, and use a liquid storage tank with a special hydrogen removal blower to achieve the purpose of hydrogen removal. When used, it is necessary to match the liquid storage tank, and install a blower and a large-diameter special hydrogen discharge pipeline, which occupies a huge space; at the same time, the existence of the liquid storage tank causes the seawater to be depressurized, and it is necessary to use a dosing pump in conjunction with the electrolyte filling.Chinese patent 201620721650.X discloses a skid-type seawater electrolysis chlorine production system, including a power supply and control system skid, a seawater filtration system skid, an electrolysis chlorine production system skid, a pickling system skid, a sodium hypochlorite storage system skid, and a dosing system skid. The seawater filtration system skid includes a seawater inlet control valve, a seawater inlet pipeline, a filtration system field control platform, an automatic backwashing filter, a seawater outlet pipeline, and a seawater outlet electromagnetic flowmeter, which are arranged on a filtration bracket. The seawater inlet control valve is arranged on the seawater inlet pipeline, and the seawater inlet pipeline and the seawater outlet pipeline are respectively connected to the water inlet and the water outlet of the automatic backwashing filter. The seawater outlet electromagnetic flowmeter is arranged on the seawater outlet pipeline; the electrolysis chlorine production system skid includes a sodium hypochlorite generator and a chlorine production system field control platform arranged on the chlorine production bracket, and the inlet of the sodium hypochlorite generator is connected to the seawater outlet pipeline; the pickling system skid includes an acid outlet control valve, an acid outlet pipeline, an acid return pipeline, a pickling pump, an acid storage tank, and The pickling system on-site control platform, the acid outlet control valve and the pickling pump are installed on the acid outlet pipeline. The inlet and outlet ends of the acid outlet pipeline are connected to the acid storage tank and the sodium hypochlorite generator respectively, and the inlet and outlet ends of the acid return pipeline are connected to the sodium hypochlorite generator and the acid storage tank respectively; the sodium hypochlorite storage system skid includes a sodium hypochlorite storage tank and a storage system on-site control platform installed on the storage bracket. The sodium hypochlorite storage tank is connected to the outlet of the sodium hypochlorite generator; the dosing system skid includes a drug inlet control valve, The drug inlet pipeline, the dosing pump, the drug outlet pipeline, the drug inlet flowmeter and the dosing system field control platform, the drug inlet pipeline is connected to the outlet of the sodium hypochlorite storage tank, the drug inlet control valve is arranged on the drug inlet pipeline, the dosing pump is arranged between the drug inlet pipeline and the drug outlet pipeline, and the drug inlet flowmeter is connected to the dosing pump; the power supply and control system skid is connected to the filtration system field control platform, the chlorine production system field control platform, the pickling system field control platform, the storage system field control platform and the dosing system field control platform through wires. Although it can effectively improve the installation efficiency, the existence of the storage system skid and the dosing system skid results in limited reduction in the occupied area; in addition, the electrolytic seawater chlorine production system using the air dilution hydrogen discharge method is often equipped with a pickling unit.Chinese patent 202210425191.0 discloses a raw seawater electrolysis chlorine production system, including: a control system, a seawater supply system, a filtration system, an electrolysis chlorine production system, a hydrogen storage and discharge system, a dosing system and a pickling system. The control system is electrically connected to the seawater supply system, the filtration system, the electrolysis chlorine production system, the hydrogen storage and discharge system, the dosing system and the pickling system. The seawater supply system is provided with at least two groups, and the multiple groups of seawater supply systems are mutually backed up by a communication control valve. The seawater supply system is connected to the electrolysis chlorine production system through the filtration system, the output end of the electrolysis chlorine production system is connected to the input end of the hydrogen storage and discharge system, the output end of the hydrogen storage and discharge system is connected to the output end of the dosing system, the pickling system is connected to the electrolysis chlorine production system and forms a pickling circuit with the electrolysis chlorine production system. The seawater supply system includes: a raw seawater inlet pipe, a seawater preheater, an inlet control valve, a seawater booster pump, a water outlet control valve, and the raw seawater inlet pipe. A seawater preheater is arranged on the top, one end of the original seawater inlet pipe is connected to seawater, the other end of the original seawater inlet pipe is connected to the seawater booster pump through the water inlet control valve, the output end of the seawater booster pump is provided with a water outlet control valve, and the output end and the input end of the seawater booster pump are provided with a filtering system. The pickling system comprises: a pickling tank, a pickling pump, a pickling outlet control valve, a pickling circulation control valve, a solution mixer, an acid mist absorber and a pickling reflux control valve. The pickling tank and the electrolytic chlorine making system pipeline connection are respectively provided with a pickling outlet control valve and a pickling reflux control valve for controlling and connecting the pickling tank and the electrolytic chlorine making system. The pickling pump is arranged at one end of the pickling tank, the acid mist absorber is arranged on the top of the pickling tank, and a fan is also arranged on one side of the pickling tank to discharge the undissolved concentrated acid vapor in the pickling tank to the acid mist absorber. A solution mixer is also connected between the pickling tank and the pickling circuit, and the pickling circulation control valve is arranged at the input end of the solution mixer. Although it can reduce the frequency of system maintenance, the addition of the pickling system further increases the space occupied by the system. Therefore, the electrolytic seawater chlorine production system using the air dilution hydrogen discharge method is more suitable for power plants and chemical plants that can provide separate plant layouts or large tankers with sufficient internal space, etc., to prevent the seawater cooling pipe system or seawater desalination pipe system from fouling. However, for ships with small internal space, or with the risk of war damage and high safety requirements, the equipped liquid storage tanks, dosing units, pickling units, etc. will occupy a large amount of space in the cabin, and the adaptability is poor. There is also a potential risk of leakage during the collection and discharge of hydrogen, which makes the existing electrolytic seawater chlorine production system unable to meet the application requirements. Therefore, an electrolytic anti-fouling device for ship seawater pipeline system is developed and designed to solve the safety problems such as the excessive volume of the anti-fouling device and potential hydrogen leakage caused by the separate collection and discharge of hydrogen during the use of the existing electrolytic seawater chlorine production device. Summary of the invention:

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art, develop and design a miniaturized electrolytic anti-fouling device for a ship seawater pipeline system that does not produce free hydrogen, and eliminate the risk of hydrogen accumulation.

[0006] In order to achieve the above-mentioned purpose, the main structure of an electrolytic anti-fouling device for a ship seawater pipeline system involved in the present invention includes a pretreatment unit and an electrolytic unit connected thereto, and an electronic control unit connected to the two respectively, wherein the main structure of the electrolytic unit is an electrolytic cell group composed of a plurality of branch-tube electrolytic cells connected in parallel through a waterway.

[0007] The main structure of the pretreatment unit involved in the present invention includes a seawater booster pump and a seawater filter, which are connected in series to boost the pressure and filter the supplied seawater respectively, provide available electrolysis water and dosing pressure for the electrolysis unit, ensure the dissolution of hydrogen, and prevent the electrolytic cell from dry burning and clogging;

[0008] The electrolysis unit has a large water flow rate and adopts a tubular electrolytic cell group with a high internal flow rate for electrolysis. The seawater flowing through the electrolytic cell is electrolyzed by direct current to produce effective chlorine. By increasing the number of electrolytic cells, the chlorine production of a single electrolytic cell can be reduced.

[0009] The electronic control unit adjusts the electrolysis current to prepare an electrolyte of a set concentration according to the solubility of hydrogen and the flow limit of the electrolyzer.

[0010] Compared with the prior art, the present invention further optimizes the composition based on the method of diluting hydrogen with seawater, simplifies the main structure into three parts: a seawater pretreatment unit, an electrolysis unit and an electronic control unit, effectively reduces the occupied space, adopts seawater dilution of hydrogen instead of air dilution of hydrogen, realizes direct discharge of electrolyte without storage, and provides a miniaturized electrolysis antifouling device for ship pipeline systems that does not generate free hydrogen, which can effectively slow down the generation of CaCO at the cathode of the electrolysis unit when electrolyzing seawater. 3 Mg(OH) 2 The scaling rate of calcium and magnesium deposits is reduced, thereby effectively reducing the frequency of electrolytic cell pickling and increasing the single continuous operation time. The hydrogen by-product of seawater electrolysis is directly dissolved in the cooling seawater and discharged outboard, eliminating the risk of hydrogen accumulation and precipitation leakage, and ensuring the safe operation of the equipment. Its composition and structure are simple, the principle is scientific and reliable, the space occupied is small, the penetration engineering is relatively small, and the adaptability is strong. There is no need to equip the ship with a dehydrogenation unit, a dosing unit and a pickling unit separately, and there is no need to design a dedicated hydrogen discharge pipeline separately. It is suitable for seawater pipeline systems of large ships. Description of the drawings:

[0011] Figure 1 It is a schematic diagram of the main structural principle of the present invention.

[0012] Figure 2 It is a schematic diagram of the main structure of the electrolysis unit involved in the present invention. Specific implementation method:

[0013] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0014] Embodiment 1:

[0015] The main structure of an electrolytic anti-fouling device for a ship seawater pipeline system according to this embodiment is as follows Figure 1 As shown, it includes a pretreatment unit 1, an electrolysis unit 2 and an electric control unit 3; the pretreatment unit 1 is connected to the electrolysis unit 2 by water, and the electric control unit 3 is connected to the pretreatment unit 1 and the electrolysis unit 2 by circuits, wherein the main structure of the electrolysis unit 2 is as shown Figure 2 As shown, a plurality of branch-type electrolytic cells 21 are connected in parallel by waterways through a seawater inlet main pipe 24 and a sodium hypochlorite solution outlet main pipe 25 to form an electrolytic cell group. A flow meter 22 and a regulating valve 23 are provided on each electrolytic cell branch. The flow meter 22 performs flow monitoring, and the regulating valve 23 controls the flow of each electrolytic cell 21 to be within the rated working flow range to prevent problems such as dry burning and rapid scaling caused by excessive flow of the electrolytic cell 21. After the sodium hypochlorite agent is output from the sodium hypochlorite solution outlet main pipe, it is distributed to the dosing point corresponding to the ship's seawater pipeline system through the dosing pipeline. The distribution of the agent is controlled by the diameter setting of the dosing pipeline and the seawater regulating valve and seawater flowmeter equipped with the dosing pipeline.

[0016] The pretreatment unit 1, electrolysis unit 2 and electric control unit 3 involved in this embodiment are independently formed into skids and arranged in a centralized or decentralized manner according to the actual ship space;

[0017] The main structure of the pretreatment unit 1 includes a seawater booster pump 11 and a seawater filter 12. The commercially available seawater booster pump 11 and the self-cleaning seawater filter 12 are connected in series to the seawater supply pipeline;

[0018] The electrolytic unit 2 has a simple pipeline interface, with water entering through the seawater inlet main pipe 24, sodium hypochlorite solution outlet main pipe 25 for discharge, and sewage discharge through the sewage pipe 26. The electrolytic cell 21, as the core component, is composed of a noble metal oxide anode and a titanium alloy cathode;

[0019] The electronic control unit 3 mainly includes a system controller 31, a rectifier 32, a hydrogen concentration sensor 33, a pressure sensor 34 and a temperature sensor 35, and has functions such as power supply, control and monitoring of working status, and interlocking alarm.

[0020] When the electrolytic anti-fouling device for a ship seawater pipeline system according to the present embodiment is used, a hydrogen concentration sensor 33 is installed in the electrolytic unit 2 and key positions, and interlocked with the electronic control unit 3 for control;

[0021] During normal operation, the pretreatment unit 1 pressurizes and filters the seawater to obtain pretreated seawater with impurities less than 3 mm. The pretreated seawater enters the electrolysis unit 2 through the seawater inlet main pipe 24, and is evenly distributed to each electrolytic cell 21 through the monitoring and allocation of the flow meter 22 and the regulating valve 23 on each electrolytic cell branch. The seawater flow rate flowing through each electrolytic cell 21 is between 4.5 and 6.8 m 3 / h, at the same time, through the control of the electronic control unit 3, the electrolyte with a concentration of ≤42ppm generated by direct current electrolysis is discharged from the sodium hypochlorite solution outlet mother pipe 25, and the electrolyte is transported to the corresponding dosing point of the ship's seawater pipeline system through the dosing pipeline by relying on the pressure provided by the seawater booster pump 11. The dosing concentration of the electrolyte is adjusted by the current output by the electronic control unit 3;

[0022] During this process, when the hydrogen concentration sensor 33 detects that the hydrogen content exceeds the set value by 2.4%, the electronic control unit 3 immediately alarms and cuts off the power supply, interrupting the electrolysis to stop the generation of hydrogen and ensure safe operation;

[0023] While not changing the seawater flow rate in a single electrolytic cell 21 and ensuring the safe operation of the electrolytic cell 21, on the one hand, the precipitation of byproduct hydrogen is reduced, so that it can be dissolved by the passing seawater immediately after it is produced, and the electrolyte does not contain free hydrogen. It is further diluted by being added to the seawater pipeline of the ship with seawater, effectively eliminating the risk of hydrogen precipitation and aggregation; on the other hand, it reduces the generation of calcium and magnesium deposits, and cooperates with the high-flow seawater flushing in the electrolytic cell to effectively alleviate the scaling problem of the electrolytic cell 21, reduce the frequency of pickling, and increase the single continuous operation time;

[0024] Compared with the traditional seawater electrolysis chlorine production device, by replacing the hydrogen dilution medium, the fans, liquid storage tanks and hydrogen discharge pipelines required for dehydrogenation are reduced; by direct discharge without a storage tank, the dosing pump required for electrolyte pressure boosting and filling is reduced; by reducing the chlorine production of a single electrolytic cell, the acid cleaning frequency is reduced, and the acid cleaning unit can be used as a non-ship unit;

[0025] Specifically, compared with the electrolytic seawater anti-fouling device with a chlorine production of 4.5 kg / h in the prior art, the electrolytic seawater anti-fouling device of this embodiment reduces the occupied space by 15%, and the pickling maintenance cycle is extended from 30-60 days to 180 days.

Claims

1. An electrolytic anti-fouling device for a ship seawater pipeline system, characterized in that: The main structure includes a pretreatment unit and an electrolysis unit connected thereto, and an electric control unit respectively connected to the pretreatment unit and the electrolysis unit. The main structure of the electrolysis unit is an electrolysis cell group composed of a plurality of branch-tube electrolysis cells connected in parallel through a water channel.

2. The electrolytic anti-fouling device for a ship seawater pipeline system according to claim 1, characterized in that: The main structure of the pretreatment unit includes a seawater booster pump and a seawater filter, which are connected in series to boost the pressure and filter the supplied seawater respectively, and provide electrolytic water and dosing pressure for the electrolysis unit.

3. The electrolytic anti-fouling device for a ship seawater pipeline system according to claim 2, characterized in that: The electrolysis unit uses a tubular electrolytic cell group with a high internal flow rate for electrolysis. The seawater flowing through the electrolytic cell is electrolyzed by direct current to produce effective chlorine. By increasing the number of electrolytic cells, the chlorine production of a single electrolytic cell can be reduced.

4. The electrolytic anti-fouling device for a ship seawater pipeline system according to claim 1 or 2, characterized in that: The electronic control unit includes a system controller, a rectifier, a hydrogen concentration sensor, a pressure sensor and a temperature sensor. It has the functions of power supply, control and monitoring of working status, and interlocking alarm. According to the solubility of hydrogen and the flow limit of the electrolytic cell, it adjusts the electrolysis current to prepare an electrolyte of a set concentration.

5. An electrolytic anti-fouling device for a ship seawater pipeline system according to any one of claims 1 to 4, characterized in that: Several branch-type electrolytic cells are connected in parallel through a seawater inlet main pipe and a sodium hypochlorite solution outlet main pipe to form an electrolytic cell group. A flow meter and a regulating valve are provided on each electrolytic cell branch. The flow meter monitors the flow rate, and the regulating valve controls the flow rate of each electrolytic cell to be within the rated working flow rate range. After the sodium hypochlorite agent is output from the sodium hypochlorite solution outlet main pipe, it is distributed to the corresponding dosing points of the ship's seawater pipeline system through the dosing pipeline. The distribution of the agent is controlled by the diameter setting of the dosing pipeline and the seawater regulating valve and seawater flowmeter equipped on the dosing pipeline.

6. The electrolytic anti-fouling device for a ship seawater pipeline system according to claim 5, characterized in that: When in use, hydrogen concentration sensors are installed in the electrolysis unit and key locations, and interlocked with the electronic control unit for control; During normal operation, the pretreatment unit pressurizes and filters the seawater to obtain pretreated seawater with impurities less than 3 mm. The pretreated seawater enters the electrolysis unit through the seawater inlet main pipe, and is evenly distributed to each electrolytic cell through the monitoring and allocation of the flowmeter and regulating valve on each electrolytic cell branch. At the same time, under the control of the electronic control unit, the electrolyte generated by direct current electrolysis is discharged from the sodium hypochlorite solution outlet main pipe, and the electrolyte is transported to the corresponding dosing point of the ship's seawater pipeline system through the dosing pipeline relying on the pressure provided by the seawater booster pump. The dosing concentration of the electrolyte is adjusted by the current output by the electronic control unit.

7. The electrolytic anti-fouling device for a ship seawater pipeline system according to claim 6, characterized in that: When the hydrogen concentration sensor detects that the hydrogen content exceeds the set value, the electronic control unit alarms and cuts off the power supply, interrupting the electrolysis.

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