Ballast water chlorination concentration monitoring method and system and ship

Abstract

The invention provides a ballast water chlorination concentration monitoring method and system and a ship. The ballast water chlorination concentration monitoring method comprises the steps that the input power PX of an electrolytic tank, the voltage UX at the two ends of the electrolytic tank, the temperature difference delta T of ballast water at an inlet and an outlet of the electrolytic tank, the flow Q of the ballast water in the electrolytic tank and the flow QB of the ballast water in a ballast water main pipeline are obtained; according to the delta T and the Q, the heating power PT of the electrolytic tank to the ballast water is calculated; according to the PX and the PT, the effective chlorine production power P of the electrolytic cell is calculated; according to P and UX, the chlorine yield GD per hour of the electrolytic cell is calculated; and calculating the chlorine concentration TRO in the ballast water main pipeline according to the GD and the QB. According to the ballast water chlorination concentration monitoring method, the chlorination concentration in the ballast water main pipeline is calculated by utilizing the idea of energy conversion, the dependence on a residual chlorine analyzer is reduced or eliminated, the cost can be reduced, and the stability and reliability of system operation are improved.

Description

Technical Field

[0001] The invention relates to the technical field of ballast water treatment, and in particular to a ballast water chlorination concentration monitoring method and system and a ship. Background Art

[0002] Ship ballast water is water added to the ship to control the balance of the ship and improve the stability of the ship. According to relevant conventions, before the ship's ballast water is discharged after use, it must be treated to meet the standards specified in the convention. Electrolysis is a commonly used ballast water treatment technology, which uses an electrolytic cell to electrolyze seawater to produce biocides such as sodium hypochlorite, and mixes it with ballast water in the ballast water main line at a certain concentration to continuously kill organisms in the ballast tank to the ballast water convention standards.

[0003] In order to ensure that the chlorine concentration in the ballast water is within the specified range, a residual chlorine analyzer is generally installed on the ballast water main line to monitor the total chlorine (or residual chlorine) concentration in the ballast water, and then adjust the chlorine production of the electrolytic cell according to the detected residual chlorine concentration to meet the relevant standards. However, due to the complex structure and high cost of the residual chlorine analyzer, the failure rate is high in actual application, and the operation and maintenance are cumbersome, which increases the procurement cost and operation and maintenance cost. Summary of the invention

[0004] The object of the present invention is to provide a ballast water chlorination concentration monitoring method and system and a ship, aiming to solve or at least partially solve the deficiencies of the above-mentioned background technology. The ballast water chlorination concentration monitoring method uses the concept of energy conversion to calculate the chlorination concentration in the ballast water main line, reduces or gets rid of the dependence on the residual chlorine analyzer, can reduce costs, and improve the stability and reliability of system operation.

[0005] The present invention provides a method for monitoring chlorination concentration of ballast water, comprising:

[0006] Get the input power P of the electrolyzer X , the voltage U at both ends of the electrolytic cell X , the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell, the flow rate Q of the ballast water in the electrolytic cell, and the flow rate Q of the ballast water in the ballast water main line B ;

[0007] According to the ΔT and the Q, the heating power P of the electrolytic cell to the ballast water is calculated. T ; Among them, P T =C*Q*ρ*ΔT*k1, wherein C is the specific heat capacity of the ballast water, ρ is the density of the ballast water, and k1 is the first unit conversion coefficient;

[0008] According to the P X and the PT , calculate the effective chlorine production power P of the electrolytic cell; where P = P X -P T ;

[0009] According to the P and the U X , calculate the chlorine production G per hour of the electrolytic cell D ; wherein the G D =G 总 *P / U X , the G 总 is the effective chlorine production of the electrolytic cell per ampere-hour of electricity;

[0010] According to the G D And the Q B , calculate the chlorination concentration TRO in the ballast water main line; wherein, TRO = G D / Q B .

[0011] Furthermore, the specific method for obtaining the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell includes:

[0012] A first temperature sensor and a second temperature sensor are respectively arranged at the inlet and the outlet of the electrolytic cell, and the first temperature sensor and the second temperature sensor are used to detect the temperature of the ballast water at the inlet and the outlet of the electrolytic cell respectively; a temperature difference ΔT of the ballast water at the inlet and the outlet of the electrolytic cell is calculated according to the temperature value detected by the first temperature sensor and the temperature value detected by the second temperature sensor;

[0013] Alternatively, a temperature difference sensor is connected to the inlet and outlet of the electrolytic cell respectively, and the temperature difference sensor is used to detect the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell.

[0014] Furthermore, the G 总 =n C *G; wherein said n C is the number of electrolytic units in the electrolytic cell, and G is the effective chlorine production of a single electrolytic unit per ampere-hour of electricity.

[0015] Further, the input power P of the electrolytic cell is obtained X and the voltage U at both ends of the electrolytic cell X The specific methods include:

[0016] Get the DC output voltage U of the rectifier DC , the DC output current I of the rectifier DC , and the total resistance value R of the cable between the rectifier and the electrolytic cell 总 ;

[0017] According to the U DC , said I DC And the R 总 , calculate the output power P of the rectifier OUT , and the heat loss power P of the cable between the rectifier and the electrolytic cell R ; wherein the P OUT =U DC *I DC , the P R =I DC 2 *R 总 ;

[0018] According to the P OUT and the P R , calculate the P X ; Among them, P X =P OUT -P R ;

[0019] According to the P R 、The U DC And the I DC , calculate the U X ; wherein the U X =U DC -U R =U DC -P R / I DC , the U R is the voltage drop on the cable between the rectifier and the electrolyzer;

[0020] Or according to the P X And the I DC , calculate the U X ; wherein the U X =P X / I DC .

[0021] Furthermore, the cable between the rectifier and the electrolytic cell includes a positive cable and a negative cable, the positive cable is connected between the positive terminal of the rectifier and the positive terminal of the electrolytic cell, and the negative cable is connected between the negative terminal of the rectifier and the negative terminal of the electrolytic cell; 总 is the sum of the resistance of the positive cable and the resistance of the negative cable.

[0022] Further, the input power P of the electrolytic cell is obtained X and the voltage U at both ends of the electrolytic cell X The specific methods include:

[0023] Get the DC output current I of the rectifier DC ;

[0024] The voltage detection device is electrically connected to the two ends of the electrolytic cell, and the voltage U at the two ends of the electrolytic cell is detected by the voltage detection device. X ;

[0025] According to the U X And the I DC , calculate the P X ; Among them, P X =U X *I DC .

[0026] The present invention also provides a ballast water chlorination concentration monitoring system based on the ballast water chlorination concentration monitoring method as described above, the ballast water chlorination concentration monitoring system comprising:

[0027] A rectifier detection module is connected to the rectifier; the rectifier detection module is at least used to detect the DC output voltage U of the rectifier DC and DC output current I DC ;

[0028] A temperature detection device, used to detect the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell;

[0029] An electrolytic cell flow meter, used to detect the flow rate Q of the ballast water in the electrolytic cell;

[0030] Main line flow meter, used to detect the flow rate Q of ballast water in the ballast water main line B ;

[0031] A data processing module is connected to the rectifier detection module, the temperature detection device, the electrolytic cell flow meter and the main line flow meter respectively; the data processing module is used to perform the following operations:

[0032] According to the U DC , said I DC and the total resistance value R of the cable between the rectifier and the electrolytic cell 总 , calculate the output power P of the rectifier OUT , and the heat loss power P of the cable between the rectifier and the electrolytic cell R ;

[0033] According to the P OUT and the P R , calculate the input power P of the electrolyzer X ;

[0034] According to the PR 、The U DC And the I DC , calculate the voltage U across the electrolytic cell X ; or, according to the P X And the I DC , calculate the voltage U across the electrolytic cell X ;

[0035] According to the ΔT and the Q, the heating power P of the electrolytic cell to the ballast water is calculated. T ;

[0036] According to the P X and the P T , calculate the effective chlorine production power P of the electrolytic cell;

[0037] According to the P and the U X , calculate the chlorine production G per hour of the electrolytic cell D ;

[0038] According to the G D And the Q B , calculate the chlorination concentration TRO in the ballast water main line.

[0039] The present invention also provides a ballast water chlorination concentration monitoring system based on the ballast water chlorination concentration monitoring method as described above, the ballast water chlorination concentration monitoring system comprising:

[0040] A rectifier detection module is connected to the rectifier; the rectifier detection module is at least used to detect the DC output current I of the rectifier DC ;

[0041] A voltage detection device is electrically connected to both ends of the electrolytic cell; the voltage detection device is used to detect the voltage U at both ends of the electrolytic cell X ;

[0042] A temperature detection device, used to detect the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell;

[0043] An electrolytic cell flow meter, used to detect the flow rate Q of the ballast water in the electrolytic cell;

[0044] Main line flow meter, used to detect the flow rate Q of ballast water in the ballast water main line B ;

[0045] A data processing module is respectively connected to the rectifier detection module, the voltage detection device, the temperature detection device, the electrolytic cell flow meter and the main line flow meter; the data processing module is used to perform the following operations:

[0046] According to the UX And the I DC , calculate the input power P of the electrolyzer X ;

[0047] According to the ΔT and the Q, the heating power P of the electrolytic cell to the ballast water is calculated. T ;

[0048] According to the P X and the P T , calculate the effective chlorine production power P of the electrolytic cell;

[0049] According to the P and the U X , calculate the chlorine production G per hour of the electrolytic cell D ;

[0050] According to the G D And the Q B , calculate the chlorination concentration TRO in the ballast water main line.

[0051] Further, the temperature detection device includes a first temperature sensor and a second temperature sensor, the first temperature sensor and the second temperature sensor are respectively connected to the inlet and the outlet of the electrolytic cell, and the first temperature sensor and the second temperature sensor are respectively used to detect the temperature of the ballast water at the inlet and the outlet of the electrolytic cell; the data processing module is respectively connected to the first temperature sensor and the second temperature sensor, and the data processing module is further used to perform the following operations: according to the temperature value detected by the first temperature sensor and the temperature value detected by the second temperature sensor, calculate the temperature difference ΔT of the ballast water at the inlet and the outlet of the electrolytic cell;

[0052] Alternatively, the temperature detection device includes a temperature difference sensor, which is respectively connected to the inlet and outlet of the electrolytic cell; the temperature difference sensor is used to detect the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell, and the data processing module is connected to the temperature difference sensor.

[0053] The present invention also provides a ship, comprising the ballast water chlorination concentration monitoring system as described above.

[0054] The ballast water chlorination concentration monitoring method provided by the present invention adopts the idea of ​​energy conversion by obtaining the input power P of the electrolytic cell. X , the voltage U across the electrolytic cell X , the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolyzer, the flow rate Q of the ballast water in the electrolyzer, and the flow rate Q of the ballast water in the ballast water main line B, the chlorination concentration TRO in the ballast water main line can be calculated; and the method for obtaining the above data is relatively simple, and the device for obtaining the relevant data is a conventional device with a simple and reliable structure and low cost. The chlorination concentration in the ballast water main line can be obtained by using the ballast water chlorination concentration monitoring method, which can reduce or get rid of the dependence on the residual chlorine analyzer, reduce costs, and improve the stability and reliability of system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a schematic structural diagram of a ship ballast water treatment system in a first embodiment of the present invention.

[0056] Figure 2 Schematic diagram of the setting position of the temperature detection device in the first embodiment of the present invention.

[0057] Figure 3 Schematic diagram of the setting position of the temperature detection device in another embodiment of the present invention.

[0058] Figure 4 It is a structural block diagram of the ballast water chlorination concentration monitoring system in the first embodiment of the present invention.

[0059] Figure 5 Schematic diagram of the arrangement position of the voltage detection device in the second embodiment of the present invention.

[0060] Figure 6 It is a structural block diagram of the ballast water chlorination concentration monitoring system in the second embodiment of the present invention. DETAILED DESCRIPTION

[0061] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0062] The terms "first", "second", "third", "fourth" and the like (if any) in the description and claims of the present invention are used to distinguish similar objects and are not necessarily used to describe a particular sequence or order.

[0063] The directional words such as up, down, left, right, front, back, top, bottom, etc. (if any) involved in the specification and claims of the present invention are defined by the positions of the structures in the drawings and the positions of the structures relative to each other, and are only for the clarity and convenience of expressing the technical solution. It should be understood that the use of directional words should not limit the scope of protection claimed in this application.

[0064] First embodiment

[0065] like Figure 1As shown, the first embodiment of the present invention provides a ballast water chlorination concentration monitoring method for monitoring / calculating the chlorination concentration TRO of the ballast water main line 101 in the ship ballast water treatment system 1.

[0066] In this embodiment, the ship ballast water treatment system 1 is a branch electrolysis ballast water treatment system, which includes a ballast water main line 101, a branch line 102, a first discharge line 103, a second discharge line 104, a ballast pump 11, a main line flow meter 12, a filter 13, a seawater pump 14, an electrolytic cell 15, a rectifier 16, a gas-liquid separation device 17, a ballast tank 18, and a valve. One end of the ballast water main line 101 is connected to the ballast tank 18, and the ballast pump 11 and the main line flow meter 12 are sequentially arranged on the ballast water main line 101. Both ends of the branch line 102 are respectively connected to the ballast water main line 101 between the main line flow meter 12 and the ballast tank 18, and the filter 13, the seawater pump 14, the electrolytic cell 15 and the gas-liquid separation device 17 are sequentially arranged on the branch line 102. The rectifier 16 is electrically connected to the electrolytic cell 15, thereby supplying power (providing direct current) to the electrolytic cell 15. One end of the first discharge pipe 103 is connected to the ballast water main pipe 101 between the main pipe flow meter 12 and the ballast tank 18, and the other end of the first discharge pipe 103 is connected to the ballast water main pipe 101 before the ballast pump 11; the second discharge pipe 104 is connected to the ballast water main pipe 101 between the main pipe flow meter 12 and the ballast tank 18.

[0067] During ballasting, the ballast pump 11 operates to provide pumping power for the ballast water (generally seawater), and the main line flow meter 12 detects the flow rate Q of the ballast water in the ballast water main line 101. B (i.e., total flow); the ballast water pressurized by the ballast pump 11 is divided into two paths, one path is directly transported to the ballast tank 18 through the ballast water main line 101, and the other path is first filtered by the filter 13, and then pressurized by the seawater pump 14 and transported to the electrolytic cell 15. The rectifier 16 supplies power to the electrolytic cell 15, and the electrolytic cell 15 electrolyzes the ballast water to generate sodium hypochlorite solution (the reaction process is: NaCl+H2O→NaClO+H2↑). The sodium hypochlorite solution is removed from the hydrogen by the gas-liquid separation device 17 and then re-injected into the ballast water main line 101, mixed with the ballast water in the ballast water main line 101 and then enters the ballast tank 18, which plays a role in continuously killing organisms.

[0068] When unloading, the ballast pump 11 operates to discharge the ballast water in the ballast tank 18 to the outside through the first unloading pipeline 103 and the second unloading pipeline 104 in sequence (the first unloading pipeline 103 and the second unloading pipeline 104 can reuse the ballast pump 11 to save costs).

[0069] The above is merely an illustrative description of a commonly used branch electrolysis ballast water treatment system, in order to facilitate the description and understanding of the following ballast water chlorination concentration monitoring method; in other embodiments, the branch electrolysis ballast water treatment system may also have other structures.

[0070] Of course, in other embodiments, the ship ballast water treatment system 1 can also be a main ballast pipeline electrolysis ballast water treatment system. In this case, there is no need to set the branch pipeline 102, but the filter 13, the electrolytic cell 15 and other devices are directly set in the ballast water main pipeline 101. In this case, the electrolytic cell 15 directly electrolyzes the ballast water in the entire ballast water main pipeline 101. The specific structure of the main ballast pipeline electrolysis ballast water treatment system can be referred to the prior art, which will not be repeated here.

[0071] Furthermore, if Figure 1 As shown, in this embodiment, the ballast water chlorination concentration monitoring method includes:

[0072] Get the input power P of the electrolytic cell 15 X (i.e., the output power of the rectifier 16 to the electrolytic cell 15 actually received by the electrolytic cell 15), the voltage U across the electrolytic cell 15 X (i.e., the voltage between the positive terminal and the negative terminal of the electrolytic cell 15), the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell 15 (i.e., the temperature difference between the ballast water at the water inlet of the electrolytic cell 15 and the ballast water at the water outlet of the electrolytic cell 15), the flow rate Q of the ballast water in the electrolytic cell 15 (i.e., the flow rate of the ballast water passing through the electrolytic cell 15), and the flow rate Q of the ballast water in the ballast water main line 101 B ;

[0073] According to the ΔT and the Q, the heating power P of the electrolytic cell 15 on the ballast water is calculated. T ; Among them, P T =C*Q*ρ*ΔT*k1, wherein C is the specific heat capacity of the ballast water, ρ is the density of the ballast water, and k1 is the first unit conversion coefficient;

[0074] According to the P X and the P T , calculate the effective chlorine production power P of the electrolytic cell 15; where P = P X -P T ;

[0075] According to the P and the U X , calculate the chlorine production G per hour of the electrolytic cell 15 D ; wherein the G D =G 总 *P / U X , the G 总is the effective chlorine production of the electrolytic cell 15 per ampere-hour of electricity;

[0076] According to the G D And the Q B , calculate the chlorine concentration TRO in the ballast water main line 101; wherein, TRO = G D / Q B .

[0077] Among them, P X , P T , P is in Watt (W), U X The unit of is volt (V), the unit of ΔT is °C, Q and Q B The unit is m 3 / h, the unit of C is J / (kg·℃), the unit of ρ is kg / m 3 , G D The unit is grams per hour (g / h), G 总 The unit of is g / (A·h), the unit of TRO is mg / L, and k1 is 1 / 3600.

[0078] Specifically, this embodiment is based on the principle of energy conservation and adopts the concept of energy conversion. Since the energy required for electrolyzing ballast water to produce sodium hypochlorite is all provided by the rectifier 16, the energy (electric energy) output by the rectifier 16 is converted into chemical energy for electrolyzing ballast water in the electrolytic cell 15 (that is, this part of the energy is used to electrolyze the ballast water), part of the energy is used to heat the ballast water flowing through the electrolytic cell 15, and a small amount of energy is used to bear the heat loss of the electrical circuit. Therefore, the conversion form of the energy output by the rectifier 16 is:

[0079] Rectifier output energy = electrolytic cell input power + electrical line heat loss energy = chlorine production energy + ballast water heating energy + electrical line heat loss energy;

[0080] Rectifier output energy: the total electrical energy output by the rectifier 16;

[0081] Electrolyzer input power: the input power from the rectifier 16 to the electrolyzer 15 actually received by the electrolyzer 15;

[0082] Chlorine production energy: the energy required for electrolyzing ballast water in electrolytic cell 15 to generate sodium hypochlorite;

[0083] Ballast water heating energy: the heat energy added by the increase in ballast water temperature during the electrolysis process;

[0084] Heat loss energy of electrical lines: heat energy generated by current in transmission lines;

[0085] The above energy relationship means that part of the electric energy output by the rectifier 16 is transmitted to the electrolytic cell 15, and the other part is consumed in the form of heat energy on the cable between the rectifier 16 and the electrolytic cell 15; wherein, part of the electric energy input by the electrolytic cell 15 is used for electrolytic chlorine production, and the other part is used for heating ballast water, so the electric energy output by the rectifier 16 is equal to the sum of the chlorine production energy, the ballast water heating energy, and the electrical line heat loss energy.

[0086] Since each energy is the product of each power and time, the above energy relationship can be converted into a power relationship, namely:

[0087] Rectifier output power = electrolytic cell input power + electrical line heat loss power = chlorine production power + ballast water heating power + electrical line heat loss power; where the electrolytic cell input power is the above P X , the rectifier output power rate is the following P OUT The chlorine production power is the above P, and the ballast water heating power is the above P T , the heat loss power of the electrical circuit is the following P R ;

[0088] That is, the above relationship is: OUT =P X +P R =P+P T +P R ;P X =P+P T .

[0089] Among them, P T It can be obtained by obtaining the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell 15 and calculating it in combination with the specific heat capacity formula. X The output power P of the rectifier 16 can be obtained by OUT , and the heat loss power P of the cable between the rectifier 16 and the electrolytic cell 15 R The voltage U at both ends of the electrolytic cell 15 can also be obtained by calculating X Then calculate it. This embodiment uses the former to obtain P X .

[0090] Specifically, in this embodiment, the input power P of the electrolytic cell 15 is obtained. X and the voltage U at both ends of the electrolytic cell 15 X The specific methods include:

[0091] Obtain the DC output voltage U of the rectifier 16 DC , the DC output current I of the rectifier 16 DC , and the total resistance value R of the cable between the rectifier 16 and the electrolytic cell 15总 ;

[0092] According to the U DC , said I DC And the R 总 , calculate the output power P of rectifier 16 OUT , and the heat loss power P of the cable between the rectifier 16 and the electrolytic cell 15 R ; wherein the P OUT =U DC *I DC , the P R =I DC 2 *R 总 (The current flowing through the cable between the rectifier 16 and the electrolytic cell 15 is I DC );

[0093] According to the P OUT and the P R , calculate the P X ; Among them, P X =P OUT -P R ;

[0094] According to the P R 、The U DC And the I DC , calculate the U X ; wherein the U X =U DC -U R =U DC -P R / I DC , the U R is the voltage drop on the cable between the rectifier 16 and the electrolytic cell 15 .

[0095] Of course, since P has been obtained at this time X and I DC , so we can also use the P X And the I DC , calculate the U X ; wherein the U X =P X / I DC (The current flowing through the electrolytic cell 15 is I DC ).

[0096] Among them, U DC The unit is volt (V), I DC The unit is ampere (A), R 总 The unit is ohm (Ω), P OUT , PR The unit is Watt (W).

[0097] Further, in this embodiment, the cables between the rectifier 16 and the electrolytic cell 15 include a positive cable 16A and a negative cable 16B, wherein the positive cable 16A is connected between the positive terminal of the rectifier 16 and the positive terminal of the electrolytic cell 15, and the negative cable 16B is connected between the negative terminal of the rectifier 16 and the negative terminal of the electrolytic cell 15; 总 It is the sum of the resistance of the positive cable 16A and the resistance of the negative cable 16B.

[0098] Among them, since the positive cable 16A and the negative cable 16B generally have the same specifications (i.e., the same parameters such as length, material, thickness, resistivity, etc.), R 总 =2*R*L*k2 / n (Since the resistance of the positive cable 16A and the negative cable 16B are the same, only the resistance of one of them can be calculated and then multiplied by two). Among them, L is the length of the positive cable 16A (or the negative cable 16B), in meters (m); R is the resistance of a single core wire per kilometer, in ohms per kilometer (Ω / km); n is the number of core wires in the positive cable 16A (or the negative cable 16B) (i.e., there are n core wires in parallel in the positive cable 16A; the number of core wires in the positive cable 16A and the negative cable 16B is the same); k2 is the second unit conversion coefficient, k2 is 1 / 1000.

[0099] Furthermore, in this embodiment, the G 总 =n C *G; wherein said n C is the number of electrolytic units (not shown) in the electrolytic cell 15 (i.e., the electrolytic cell 15 is composed of a plurality of electrolytic units), and G is the effective chlorine production per ampere-hour of a single electrolytic unit. C It is determined by the manufacturer's parameters of the electrolytic cell 15; G is generally an existing value, G is 1.323 g / (A·h), and the data comes from "GB / T 22839-2010 Technical Requirements for Sodium Hypochlorite Generation Devices for Electrolysis of Seawater".

[0100] Furthermore, if Figure 2 As shown, in this embodiment, the specific method for obtaining the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell 15 includes:

[0101] A first temperature sensor 21 and a second temperature sensor 22 are respectively arranged at the inlet and the outlet of the electrolytic cell 15 (the first temperature sensor 21 and the second temperature sensor 22 can be directly connected to the inlet and the outlet of the electrolytic cell 15, respectively, or can be connected to the inlet pipeline and the outlet pipeline of the electrolytic cell 15, respectively). The first temperature sensor 21 and the second temperature sensor 22 are used to detect the temperature of the ballast water at the inlet and the outlet of the electrolytic cell 15, respectively; according to the temperature value detected by the first temperature sensor 21 and the temperature value detected by the second temperature sensor 22, the temperature difference ΔT of the ballast water at the inlet and the outlet of the electrolytic cell 15 is calculated; that is, ΔT=the temperature value detected by the second temperature sensor 22-the temperature value detected by the first temperature sensor 21.

[0102] like Figure 3 As shown, in another embodiment, a specific method for obtaining the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell 15 includes:

[0103] The temperature difference sensor 23 is connected to the inlet and outlet of the electrolytic cell 15 respectively (the temperature difference sensor 23 can be directly connected to the inlet and outlet of the electrolytic cell 15 respectively, or can be connected to the inlet pipeline and outlet pipeline of the electrolytic cell 15 respectively), and the temperature difference sensor 23 is used to detect the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell 15.

[0104] Of course, in other embodiments, only one temperature sensor may be provided at the outlet of the electrolytic cell 15, and the temperature sensor may be used to detect the ballast water temperature of the electrolytic cell 15 before and after operation, respectively, and the temperature rise of the ballast water in the electrolytic cell 15 may also be calculated (of course, the accuracy of this method is relatively low).

[0105] like Figure 1 , Figure 2 and Figure 4 As shown, this embodiment also provides a ballast water chlorination concentration monitoring system based on the above-mentioned ballast water chlorination concentration monitoring method, which is used in a ship ballast water treatment system 1. The ballast water chlorination concentration monitoring system includes:

[0106] The rectifier detection module 161 is connected to the rectifier 16; the rectifier detection module 161 is at least used to detect the DC output voltage U of the rectifier 16. DC and DC output current I DC ;

[0107] The temperature detection device 2 is used to detect the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell 15;

[0108] An electrolytic cell flow meter 151, used to detect the flow rate Q of the ballast water in the electrolytic cell 15;

[0109] The main line flow meter 12 is used to detect the flow rate Q of the ballast water in the ballast water main line 101. B ;

[0110] The data processing module 4 is respectively connected to the rectifier detection module 161, the temperature detection device 2, the electrolytic cell flow meter 151 and the main line flow meter 12 (specifically, electrical signal connection); the data processing module 4 is used to perform the following operations:

[0111] According to the U DC , said I DC and the total resistance value R of the cable between the rectifier 16 and the electrolytic cell 15 总 (R 总 can be preset in the data processing module 4), calculate the output power P of the rectifier 16 OUT , and the heat loss power P of the cable between the rectifier 16 and the electrolytic cell 15 R ;

[0112] According to the P OUT and the P R , calculate the input power P of the electrolytic cell 15 X ;

[0113] According to the P R 、The U DC And the I DC , calculate the voltage U at both ends of the electrolytic cell 15 X ; or, according to the P X And the I DC , calculate the voltage U at both ends of the electrolytic cell 15 X ;

[0114] According to the ΔT and the Q, the heating power P of the electrolytic cell 15 on the ballast water is calculated. T ;

[0115] According to the P X and the P T , calculate the effective chlorine production power P of the electrolytic cell 15;

[0116] According to the P and the U X , calculate the chlorine production G per hour of the electrolytic cell 15 D ;

[0117] According to the G D And the Q B , calculate the chlorination concentration TRO in the ballast water main line 101.

[0118] The calculation formulas of each step can refer to the above-mentioned ballast water chlorination concentration monitoring method, which will not be repeated here.

[0119] Furthermore, in this embodiment, the rectifier detection module 161 is generally a current, voltage or power sensor set in the rectifier 16 (this is the standard configuration of the rectifier 16), so no additional setting is required. The electrolytic cell flow meter 151 can be set in the electrolytic cell 15, on the inlet pipeline of the electrolytic cell 15, on the outlet pipeline of the electrolytic cell 15, etc.; it should be noted that since this embodiment adopts the branch electrolysis method, it is necessary to additionally set the electrolytic cell flow meter 151 to detect the ballast water flow of the branch; when the main ballast pipeline electrolysis method is adopted, since the electrolytic cell 15 is set on the ballast water main pipeline 101, at this time Q is equal to Q B , the electrolytic tank flow meter 151 may not be provided (or the electrolytic tank flow meter 151 is the main line flow meter 12 ). The main line flow meter 12 is provided on the ballast water main line 101 .

[0120] Furthermore, if Figure 2 As shown, in this embodiment, the temperature detection device 2 includes a first temperature sensor 21 and a second temperature sensor 22, the first temperature sensor 21 and the second temperature sensor 22 are respectively connected to the inlet and outlet of the electrolytic cell 15, and the first temperature sensor 21 and the second temperature sensor 22 are respectively used to detect the temperature of the ballast water at the inlet and outlet of the electrolytic cell 15; the data processing module 4 is respectively connected to the first temperature sensor 21 and the second temperature sensor 22, and the data processing module 4 is also used to perform the following operations: according to the temperature value detected by the first temperature sensor 21 and the temperature value detected by the second temperature sensor 22, calculate the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell 15; that is, ΔT = the temperature value detected by the second temperature sensor 22 - the temperature value detected by the first temperature sensor 21.

[0121] like Figure 3 As shown, in another embodiment, the temperature detection device 2 includes a temperature difference sensor 23, and the temperature difference sensor 23 is respectively connected to the inlet and outlet of the electrolytic cell 15; the temperature difference sensor 23 is used to detect the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell 15, and the data processing module 4 is connected to the temperature difference sensor 23.

[0122] Furthermore, in this embodiment, the data processing module 4 may be a separate module or a module integrated in the controller. The data processing module 4 may specifically be an arithmetic unit, an MCU (micro control unit), or the like.

[0123] Furthermore, if Figure 4As shown, in this embodiment, the ballast water chlorination concentration monitoring system also includes a display device 5, which is connected to the data processing module 4 (specifically, an electrical signal connection), and the data processing module 4 is also used to transmit the calculated TRO value to the display device 5, so as to display the TRO value through the display device 5. At the same time, when the TRO value is not within the preset range, the corresponding alarm information can also be displayed through the display device 5 to remind (of course, an additional alarm device, such as an audible and visual alarm, can also be provided, and when the TRO value is not within the preset range, the corresponding alarm information is issued through the alarm device).

[0124] Furthermore, in the present embodiment, the data processing module 4 is also connected to a control unit (not shown) in the ship ballast water treatment system 1. The control unit adjusts the current output by the rectifier 16 to the electrolytic cell 15 according to the TRO value calculated by the data processing module 4, thereby controlling the chlorine production of the electrolytic cell 15 so that the chlorine concentration TRO in the ballast water main line 101 is within a preset range.

[0125] This embodiment also provides a ship, comprising the ballast water chlorination concentration monitoring system as described above.

[0126] The following specifically describes the calculation process of the chlorination concentration TRO of the ballast water main line 101 in this embodiment:

[0127] (1) Calculate the output power P of the rectifier 16 OUT :

[0128] The current, voltage or power sensor installed inside the rectifier 16 can obtain relatively accurate output voltage and output current values. After obtaining the measurement data, the following conversion can be performed:

[0129] P OUT =U DC *I DC ; Among them, P OUT The unit is Watt (W); U DC is the DC output voltage of the rectifier 16, in volts (V); I DC is the DC output current of the rectifier 16, in ampere (A).

[0130] (2) Calculate the heating power P of ballast water T :

[0131] During the electrolysis process of the system, the seawater flowing through the electrolytic cell 15 at high speed will take away the heat generated by the electrolytic cell 15, and the temperature of the seawater itself will rise. By installing temperature (or temperature difference) sensors at the inlet and outlet of the electrolytic cell 15, the temperature difference can be accurately monitored. Combined with the flow rate Q of the ballast water flowing through the electrolytic cell 15, the power consumption of the electrolytic cell 15 heating the seawater can be converted into:

[0132] P T =C*Q*ρ*ΔT*k1; where P T The unit of is watt (W); the unit of C is J / (kg·℃), and the unit of ρ is kg / m 3 The ballast water in this embodiment is seawater, the specific heat capacity C of seawater is 4096 J / (kg·℃), and the average density ρ of seawater is 1.025×10 3 kg / m 3 ; Q is the flow rate of ballast water in the electrolytic cell 15, in m 3 / h; ΔT is the temperature difference of the ballast water at the inlet and outlet of the electrolytic cell 15, in °C; k1 is 1 / 3600.

[0133] (3) Calculate the heat loss power P of the cable between the rectifier 16 and the electrolytic cell 15 R And voltage drop U R :

[0134] The heat loss power of the cable line from the rectifier 16 to the electrolytic cell 15 during the electrolysis process is determined by the output current of the rectifier 16 and the line cable resistance. The line cable resistance is related to the cable resistance parameter per kilometer, the cable length used, and the number of cable cores.

[0135] P R =I DC 2 *R 总 =I DC 2 *2*R*L*k2 / n;U R =P R / I DC ; Among them, P R The unit is Watt (W); I DC is the DC output current of the rectifier 16, in ampere (A); U R The unit is volt (V); L is the length of the positive cable 16A (or the negative cable 16B), the unit is meter (m); R is the resistance value of a single core wire per kilometer of length, the unit is ohm per kilometer (Ω / km); n is the number of core wires in the positive cable 16A (or the negative cable 16B) (that is, there are n core wires connected in parallel in the positive cable 16A); k2 is the second unit conversion coefficient, k2 is 1 / 1000.

[0136] (4) Calculate the effective chlorine production power P of the electrolytic cell 15:

[0137] P=P OUT -P R -P T =P X -P T Among them, P, P OUT, P R , P X , P T The unit is Watt (W).

[0138] (5) Calculate the chlorine production G per hour of electrolytic cell 15 D :

[0139] G D =G 总 *P / U X =n C *G*P / (U DC -U R ), where G D The unit is grams per hour (g / h); G 总 U is the effective chlorine production of the electrolytic cell 15 per ampere-hour of electricity, in g / (A·h); X , U DC , U R The unit is volt (V); n C is the number of electrolytic units in the electrolytic cell 15; G is the effective chlorine generation of a single electrolytic unit per ampere-hour of electricity, in g / (A·h), G is generally the existing value, G is 1.323 g / (A·h), and the data is from "GB / T 22839-2010 Technical Requirements for Sodium Hypochlorite Generation Devices for Electrolyzing Seawater".

[0140] (6) Calculate the real-time chlorine concentration TRO in the ballast water main line 101:

[0141] TRO=G D / Q B ; Among them, the unit of TRO is mg / L, G D The unit is grams per hour (g / h), Q B The unit is m 3 / h.

[0142] After analyzing the energy conversion of the electrolytic ship ballast water treatment system, it can be seen that as long as the corresponding measurement conditions are met to obtain various parameters, it is feasible to convert the real-time TRO concentration of ballast water by monitoring the energy conversion.

[0143] The ballast water chlorination concentration monitoring method provided in the embodiment of the present invention adopts the concept of energy conversion by obtaining the input power P of the electrolytic cell 15. X , the voltage U at both ends of the electrolytic cell 15 X , the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell 15, the flow rate Q of the ballast water in the electrolytic cell 15, and the flow rate Q of the ballast water in the ballast water main line 101 B, the chlorination concentration TRO in the ballast water main line 101 can be calculated; and the method for obtaining the above data is relatively simple, and the device for obtaining the relevant data is a conventional device with a simple and reliable structure and low cost. The chlorination concentration in the ballast water main line is obtained by using the ballast water chlorination concentration monitoring method, which can reduce or get rid of the dependence on the residual chlorine analyzer, reduce costs, and improve the stability and reliability of system operation.

[0144] Second embodiment

[0145] like Figure 5 and Figure 6 As shown, the second embodiment of the present invention provides a ballast water chlorination concentration monitoring method and a ballast water chlorination concentration monitoring system, which are basically the same as the first embodiment, and the difference is mainly in obtaining the input power P of the electrolytic cell 15. X and the voltage U at both ends of the electrolytic cell 15 X The specific methods and devices are different.

[0146] Specifically, in the ballast water chlorination concentration monitoring method of this embodiment, the input power P of the electrolytic cell 15 is obtained. X and the voltage U at both ends of the electrolytic cell 15 X The specific methods include:

[0147] Get the DC output current I of the rectifier 16 DC ;

[0148] The voltage detection device 3 is electrically connected to the two ends of the electrolytic cell 15, and the voltage detection device 3 is used to detect the voltage U at the two ends of the electrolytic cell 15. X ;

[0149] According to the U X And the I DC , calculate the P X ; Among them, P X =U X *I DC .

[0150] Among them, I DC The unit is ampere (A), U X The unit is volt (V), P X The unit is Watt (W).

[0151] Since the voltage detection device 3 is used in this embodiment to directly detect the voltage U at both ends of the electrolytic cell 15 X , there is no need to consider the heat loss power of the cable between the rectifier 16 and the electrolytic cell 15, and the calculation process is simpler, but an additional voltage detection device 3 needs to be set up.

[0152] The other steps of the ballast water chlorination concentration monitoring method in this embodiment are the same or similar to those in the first embodiment and are not described in detail here.

[0153] like Figure 1 , Figure 5 and Figure 6 As shown, this embodiment also provides a ballast water chlorination concentration monitoring system based on the above-mentioned ballast water chlorination concentration monitoring method, which is used in a ship ballast water treatment system 1. The ballast water chlorination concentration monitoring system includes:

[0154] The rectifier detection module 161 is connected to the rectifier 16; the rectifier detection module 161 is at least used to detect the DC output current I of the rectifier 16. DC ;

[0155] The voltage detection device 3 is electrically connected to both ends of the electrolytic cell 15 (specifically, electrically connected to the positive terminal and the negative terminal of the electrolytic cell 15); the voltage detection device 3 is used to detect the voltage U at both ends of the electrolytic cell 15 X ;

[0156] A temperature detection device 2, used to detect the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell 15;

[0157] An electrolytic cell flow meter 151, used to detect the flow rate Q of the ballast water in the electrolytic cell 15;

[0158] The main line flow meter 12 is used to detect the flow rate Q of the ballast water in the ballast water main line 101. B ;

[0159] The data processing module 4 is respectively connected to the rectifier detection module 161, the voltage detection device 3, the temperature detection device 2, the electrolytic cell flow meter 151 and the main line flow meter 12 (specifically, electrical signal connection); the data processing module 4 is used to perform the following operations:

[0160] According to the U X And the I DC , calculate the input power P of the electrolytic cell 15 X ;

[0161] According to the ΔT and the Q, the heating power P of the electrolytic cell 15 on the ballast water is calculated. T ;

[0162] According to the P X and the P T , calculate the effective chlorine production power P of the electrolytic cell 15;

[0163] According to the P and the U X , calculate the chlorine production G per hour of the electrolytic cell 15D ;

[0164] According to the G D And the Q B , calculate the chlorination concentration TRO in the ballast water main line 101.

[0165] The calculation formulas of each step can refer to the above-mentioned ballast water chlorination concentration monitoring method, which will not be repeated here.

[0166] Further, in this embodiment, the temperature detection device 2 includes a first temperature sensor 21 and a second temperature sensor 22, the first temperature sensor 21 and the second temperature sensor 22 are respectively connected to the inlet and outlet of the electrolytic cell 15, and the first temperature sensor 21 and the second temperature sensor 22 are respectively used to detect the temperature of the ballast water at the inlet and outlet of the electrolytic cell 15; the data processing module 4 is respectively connected to the first temperature sensor 21 and the second temperature sensor 22, and the data processing module 4 is also used to perform the following operations: according to the temperature value detected by the first temperature sensor 21 and the temperature value detected by the second temperature sensor 22, calculate the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell 15; that is, ΔT = the temperature value detected by the second temperature sensor 22 - the temperature value detected by the first temperature sensor 21.

[0167] In another embodiment, the temperature detection device 2 includes a temperature difference sensor 23, which is respectively connected to the inlet and outlet of the electrolytic cell 15; the temperature difference sensor 23 is used to detect the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell 15, and the data processing module 4 is connected to the temperature difference sensor 23.

[0168] The other structures and working principles of the ballast water chlorination concentration monitoring system in this embodiment are the same as or similar to those in the first embodiment and are not described in detail here.

[0169] Examples

[0170] Usually, if a ship is equipped with an electrolytic ballast water treatment system, the system will generally have one or more residual chlorine analyzers (the TRO instruments described below) to monitor the real-time TRO value in the ballast water pipeline. The following uses the operating data of the ballast water treatment system of a bulk carrier as an example to analyze the feasibility of using energy conversion to calculate the real-time TRO value, and compare it with the measurement reading of the residual chlorine analyzer. The data of the actual ship operation are as follows.

[0171] (1) Basic information of bulk carrier:

[0172] Ship type: 61,000 ton bulk carrier

[0173] Ballast pump rated flow: 900m3 / h×2 units

[0174] Ballast Water Treatment System: BWMS BC2000, 1 set

[0175] Ballast water treatment method: filtration + branch electrolysis (electrolysis of seawater to produce sodium hypochlorite)

[0176] In the actual ship example process, the above data is used as a reference.

[0177] (2) Actual ship operation data of ballast water treatment system on bulk carriers:

[0178] Ballast handling operation data sheet for bulk carriers

[0179]

[0180]

[0181] (3) Monitoring and calculation process parameters of ballast water treatment system for bulk carriers:

[0182] Monitoring parameter table of ballast water treatment system for bulk carriers

[0183]

[0184] (4) TRO calculation data:

[0185] According to the existing data and parameters, combined with the above calculation formula, the final TRO calculation data is shown in the following table. Among them, items 1 and 2 are the system and TRO instrument startup process. During this process, the TRO calculation data has a higher reference value than the instrument data; items 3 and 4 are the normal working state of the system. The calculation data is close to the normal working instrument measurement readings, and the two are highly consistent (generally speaking, the deviation between the two is acceptable within 20%).

[0186] Comparison table of measured data and instrument readings

[0187]

[0188] Note: After startup, the meter begins periodic measurement, and the reading will gradually increase from 0; because the TRO meter water intake pipeline has a certain length, the water sample needs to flow through the pipeline to reach the meter, and its detection data will be delayed for a certain period of time.

[0189] (5) Improvement of seawater temperature rise measurement:

[0190] In this monitoring method, the temperature rise data of seawater flowing through the electrolytic cell is a very important data, and its measurement accuracy will directly affect the final monitoring accuracy. At present, the electrolysis ballast water treatment system usually configures a temperature sensor in the outlet pipe of the electrolytic cell, so it is impossible to accurately monitor the temperature rise of seawater flowing through the electrolytic cell in real time. Relatively small temperature measurement deviations can also affect the final calculated TRO value to a certain extent. By installing two temperature sensors on the inlet and outlet pipes of the electrolytic cell at the same time or installing temperature difference sensors, and determining the appropriate temperature difference accuracy, the deviation of the TRO calculated value can be kept within an appropriate range. Taking the fourth group of data in the above table as an example, the impact of temperature difference measurement error on TRO calculated data is shown in the table below.

[0191]

[0192] From the data in the table above, we can see that when the temperature rise deviation is 0.2℃, the deviation of the calculated TRO value is about 8.5%, which is close to the accuracy of the residual chlorine analyzer actually used (±10%). Therefore, it is necessary to reasonably select the temperature difference measuring instrument and optimize the installation design so that the measured temperature difference accuracy deviation is not higher than ±0.2℃. At present, most commercially available temperature sensors and temperature difference sensors can meet this accuracy.

[0193] In addition, the flow rate of seawater passing through the electrolytic cell will also affect the measurement accuracy of the temperature rise. Generally, the temperature rise of a system with a larger water flow rate is relatively small, and the temperature difference measurement accuracy is also more affected. Therefore, compared with the ballast water treatment system of the main ballast pipeline electrolysis method, the branch electrolysis treatment system with a ballast water flow rate of about one percent of the main ballast pipeline is more suitable for using this monitoring method (the ballast water temperature rise of the branch is larger, and the temperature rise measurement accuracy is higher).

[0194] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for monitoring chlorination concentration of ballast water, characterized in that: include: Get the input power P of the electrolyzer X , the voltage U at both ends of the electrolytic cell X , the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell, the flow rate Q of the ballast water in the electrolytic cell, and the flow rate Q of the ballast water in the ballast water main line B ; According to the ΔT and the Q, the heating power P of the electrolytic cell to the ballast water is calculated. T ; Among them, P T =C*Q*ρ*ΔT*k1, wherein C is the specific heat capacity of the ballast water, ρ is the density of the ballast water, and k1 is the first unit conversion coefficient; According to the P X and the P T , calculate the effective chlorine production power P of the electrolytic cell; where P = P X -P T ; According to the P and the U X , calculate the chlorine production G per hour of the electrolytic cell D ; wherein the G D =G 总 *P / U X , the G 总 is the effective chlorine production of the electrolytic cell per ampere-hour of electricity; According to the G D And the Q B , calculate the chlorination concentration TRO in the ballast water main line; wherein, TRO = G D / Q B .

2. The method for monitoring chlorination concentration of ballast water according to claim 1, characterized in that: The specific method for obtaining the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell includes: A first temperature sensor and a second temperature sensor are respectively arranged at the inlet and the outlet of the electrolytic cell, and the first temperature sensor and the second temperature sensor are used to detect the temperature of the ballast water at the inlet and the outlet of the electrolytic cell respectively; a temperature difference ΔT of the ballast water at the inlet and the outlet of the electrolytic cell is calculated according to the temperature value detected by the first temperature sensor and the temperature value detected by the second temperature sensor; Alternatively, a temperature difference sensor is connected to the inlet and outlet of the electrolytic cell respectively, and the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell is detected by the temperature difference sensor.

3. The method for monitoring chlorination concentration of ballast water according to claim 1, characterized in that: The G 总 =n C *G; wherein said n C is the number of electrolytic units in the electrolytic cell, and G is the effective chlorine production of a single electrolytic unit per ampere-hour of electricity.

4. The method for monitoring chlorination concentration of ballast water according to any one of claims 1 to 3, characterized in that: Get the input power P of the electrolytic cell X and the voltage U at both ends of the electrolytic cell X The specific methods include: Get the DC output voltage U of the rectifier DC , the DC output current I of the rectifier DC , and the total resistance value R of the cable between the rectifier and the electrolytic cell 总 ; According to the U DC , said I DC And the R 总 , calculate the output power P of the rectifier OUT , and the heat loss power P of the cable between the rectifier and the electrolytic cell R ; wherein the P OUT =U DC *I DC , the P R =I DC 2 *R 总 ; According to the P OUT and the P R , calculate the P X ; Among them, P X =P OUT -P R ; According to the P R 、The U DC And the I DC , calculate the U X ; wherein the U X =U DC -U R =U DC -P R / I DC , the U R is the voltage drop on the cable between the rectifier and the electrolyzer; Or according to the P X And the I DC , calculate the U X ; wherein the U X =P X / I DC .

5. The method for monitoring chlorination concentration of ballast water according to claim 4, characterized in that: The cables between the rectifier and the electrolytic cell include a positive cable and a negative cable, wherein the positive cable is connected between the positive terminal of the rectifier and the positive terminal of the electrolytic cell, and the negative cable is connected between the negative terminal of the rectifier and the negative terminal of the electrolytic cell; 总 is the sum of the resistance of the positive cable and the resistance of the negative cable.

6. The method for monitoring chlorination concentration of ballast water according to any one of claims 1 to 3, characterized in that: Get the input power P of the electrolytic cell X and the voltage U at both ends of the electrolytic cell X The specific methods include: Get the DC output current I of the rectifier DC ; The voltage detection device is electrically connected to the two ends of the electrolytic cell, and the voltage U at the two ends of the electrolytic cell is detected by the voltage detection device. X ; According to the U X And the I DC , calculate the P X ; wherein the P X =U X *I DC .

7. A ballast water chlorination concentration monitoring system based on the ballast water chlorination concentration monitoring method according to claim 4, characterized in that: The ballast water chlorination concentration monitoring system comprises: A rectifier detection module is connected to the rectifier; the rectifier detection module is at least used to detect the DC output voltage U of the rectifier DC and DC output current I DC ; A temperature detection device, used to detect the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell; An electrolytic cell flow meter, used to detect the flow rate Q of the ballast water in the electrolytic cell; Main line flow meter, used to detect the flow rate Q of ballast water in the ballast water main line B ; A data processing module is connected to the rectifier detection module, the temperature detection device, the electrolytic cell flow meter and the main line flow meter respectively; the data processing module is used to perform the following operations: According to the U DC , said I DC and the total resistance value R of the cable between the rectifier and the electrolytic cell 总 , calculate the output power P of the rectifier OUT , and the heat loss power P of the cable between the rectifier and the electrolytic cell R ; According to the P OUT and the P R , calculate the input power P of the electrolyzer X ; According to the P R 、The U DC And the I DC , calculate the voltage U across the electrolytic cell X ; or, according to the P X And the I DC , calculate the voltage U across the electrolytic cell X ; According to the ΔT and the Q, the heating power P of the electrolytic cell to the ballast water is calculated. T ; According to the P X and the P T , calculate the effective chlorine production power P of the electrolytic cell; According to the P and the U X , calculate the chlorine production G per hour of the electrolytic cell D ; According to the G D And the Q B , calculate the chlorination concentration TRO in the ballast water main line.

8. A ballast water chlorination concentration monitoring system based on the ballast water chlorination concentration monitoring method according to claim 6, characterized in that: The ballast water chlorination concentration monitoring system comprises: A rectifier detection module is connected to the rectifier; the rectifier detection module is at least used to detect the DC output current I of the rectifier DC ; A voltage detection device is electrically connected to both ends of the electrolytic cell; the voltage detection device is used to detect the voltage U at both ends of the electrolytic cell X ; A temperature detection device, used to detect the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell; An electrolytic cell flow meter, used to detect the flow rate Q of the ballast water in the electrolytic cell; Main line flow meter, used to detect the flow rate Q of ballast water in the ballast water main line B ; A data processing module is respectively connected to the rectifier detection module, the voltage detection device, the temperature detection device, the electrolytic cell flow meter and the main line flow meter; the data processing module is used to perform the following operations: According to the U X And the I DC , calculate the input power P of the electrolyzer X ; According to the ΔT and the Q, the heating power P of the electrolytic cell to the ballast water is calculated. T ; According to the P X and the P T , calculate the effective chlorine production power P of the electrolytic cell; According to the P and the U X , calculate the chlorine production G per hour of the electrolytic cell D ; According to the G D And the Q B , calculate the chlorination concentration TRO in the ballast water main line.

9. The ballast water chlorination concentration monitoring system according to claim 7 or 8, characterized in that: The temperature detection device includes a first temperature sensor and a second temperature sensor, the first temperature sensor and the second temperature sensor are respectively connected to the inlet and the outlet of the electrolytic cell, and the first temperature sensor and the second temperature sensor are respectively used to detect the temperature of the ballast water at the inlet and the outlet of the electrolytic cell; the data processing module is respectively connected to the first temperature sensor and the second temperature sensor, and the data processing module is further used to perform the following operations: according to the temperature value detected by the first temperature sensor and the temperature value detected by the second temperature sensor, calculate the temperature difference ΔT of the ballast water at the inlet and the outlet of the electrolytic cell; Alternatively, the temperature detection device includes a temperature difference sensor, which is respectively connected to the inlet and outlet of the electrolytic cell; the temperature difference sensor is used to detect the temperature difference ΔT of the ballast water at the inlet and outlet of the electrolytic cell, and the data processing module is connected to the temperature difference sensor.

10. A ship, characterized in that: It comprises a ballast water chlorination concentration monitoring system as described in any one of claims 7 to 9.

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