Ship ballast water treatment device and its detection methods for power, flow rate and light transmittance

Abstract

The present invention discloses a ship ballast water treatment device and a method for detecting its power, flow rate and light transmittance, which belongs to the technical field of ship ballast water treatment; the treatment device includes an ultraviolet reactor and a control system. The control system is provided with an ultraviolet control unit, a system control unit and a power supply unit. An ultraviolet lamp tube is arranged inside the ultraviolet reactor, and an ultraviolet light intensity meter is connected to the ultraviolet reactor. The ultraviolet reactor is connected to the control system; the present invention adjusts the flow rate and power of the ballast water treatment device in real time according to the real-time detection and calculation of the ultraviolet light transmittance, so as to ensure the ultraviolet sterilization effect while saving the ship's energy consumption; moreover, the operation of the present invention is simple and convenient, easy to implement, with high detection accuracy and small calculation error, and can truly reflect the actual absorption amount of multi-band ultraviolet light by complex water quality in actual engineering applications, and realize real-time in-situ online detection and calculation of the ultraviolet reactor using multi-band ultraviolet light.

Description

Technical Field

[0001] This application belongs to the technical field of ship ballast water treatment. More specifically, it relates to a ship ballast water treatment device and a method for detecting its power, flow rate, and light transmittance. Background Art

[0002] The uncontrolled discharge of ship ballast water and sediments leads to the transfer of harmful aquatic organisms and pathogens, causing damage or harm to the environment, human health, property, and resources. The ultraviolet sterilization technology is an environmentally friendly and efficient pure physical treatment process without secondary pollution and is widely used in ship ballast water treatment. The ultraviolet irradiation dose is a key design parameter of the ultraviolet sterilization technology, which directly determines the sterilization effect. The greater the irradiation dose, the better the sterilization effect. Currently, the irradiation dose in most ballast water treatment systems is roughly estimated by multiplying the current ultraviolet irradiation intensity by the residence time of water flow in the sterilization device cavity, resulting in a large error.

[0003] When ultraviolet light is applied to the field of ship ballast water treatment, the ultraviolet light intensity directly determines the treatment effect. Due to different water qualities having different absorption degrees of ultraviolet light, if this absorption characteristic cannot be detected in a timely and accurate manner, it is easy to cause poor treatment effects, bringing serious consequences to downstream use or advanced treatment. Currently, the method for detecting the light transmittance of ultraviolet water quality in the laboratory is to use a spectrophotometer to calculate and measure the ultraviolet light intensity detected after a beam of parallel single-band ultraviolet light with a wavelength of 254 nm vertically passes through 1 cm of the test water quality, which is also a commonly used detection method internationally.

[0004] However, in practical engineering applications, the ultraviolet light used is mostly multi-band ultraviolet light. It is difficult to confirm the incident ultraviolet light intensity UVI0, the water quality conditions to be treated are relatively complex, and it is very difficult to control the distance between the ultraviolet light intensity meter and the lamp tube at 1 cm in actual products. Therefore, in practical engineering applications, the limitations of the laboratory measurement method are relatively large and cannot quickly and accurately reflect the absorption of multi-band ultraviolet light by complex water qualities. Summary of the Invention

[0005] This application aims at the technical problems existing in the prior art and provides a ship ballast water treatment device.

[0006] To solve the above technical problems, the present invention includes an ultraviolet reactor and a control system. The control system is provided with an ultraviolet control unit, a system control unit, and a power supply unit. An ultraviolet lamp tube is arranged inside the ultraviolet reactor. An ultraviolet light intensity meter is connected to the ultraviolet reactor. The ultraviolet reactor is connected to the control system. A flow rate adjustment and monitoring device is connected to the inlet and outlet of the ultraviolet reactor.

[0007] Preferably, a plurality of ultraviolet lamps are arranged in the ultraviolet reactor, and a purple outer sleeve is arranged outside the ultraviolet lamps. The distance between the inner end of the ultraviolet light intensity meter and the outer surface of the relatively arranged purple outer sleeve is d. Flow meters and proportional regulating valves are respectively connected to the inlet pipeline and the outlet pipeline of the ultraviolet reactor, and both the flow meter and the proportional regulating valve are connected to the control system.

[0008] The present invention also provides a method for detecting the ultraviolet transmittance of ship ballast water, including the following steps:

[0009] Step 1: Install the ultraviolet light intensity meter so that the signal receiving window of the ultraviolet light intensity meter faces the ultraviolet lamp in the ultraviolet reactor. At the same time, adjust the distance d between the signal receiving window of the ultraviolet light intensity meter and the purple outer sleeve outside the relatively arranged ultraviolet lamp to 2 cm.

[0010] Step 2: Pass clear water with UVT≥95% and turbidity≤3 NTU through the ultraviolet reactor, record the reading of the ultraviolet light intensity meter, and record this reading as 95% UVI 0 ;

[0011] Step 3: Add sodium lignosulfonate, corn starch and kaolin to the clear water with UVT≥95% and turbidity≤3 NTU in proportion, and adjust the UVT to UVT = 90%.

[0012] Step 4: Pass the water with adjusted proportion through the ultraviolet reactor, record the reading of the ultraviolet light intensity meter, and record this reading as 90% UVI 0 ;

[0013] Step 5: Repeat Step 3 and Step 4, respectively prepare the water to UVT = 80%, 75%, 70%, 60%, 50%, 40%, and pass the water with different UVT through the ultraviolet reactor respectively. Record the reading of the ultraviolet light intensity meter, and record this reading as 80%, 75%, 70%, 60%, 50%, 40% UVI 0 ;

[0014] Step 6: Make a calibration curve according to the UVI detected by different water with UVT. The abscissa is UVT and the ordinate is UVI.

[0015] Step 7: Pass the water to be measured through the ultraviolet reactor, record the reading of the ultraviolet light intensity meter, and record this reading as UVI d ;

[0016] Step 8: Make UVI d intersect with the calibration curve made in Step 6, take the UVI values at 2 places near the intersection point, calculate the UVI / UVI 0 ratio, and determine the value of the correction coefficient F according to the calculated UVI / UVI 0 ratio.

[0017] Step Nine: Substitute UVI 0 , UVI d and the F value into the following formula:

[0018]

[0019] Calculate the corresponding UVT d .

[0020] Preferably, in Step One, the signal receiving window of the ultraviolet light intensity meter forms a 90-degree angle with the axial direction of the opposite ultraviolet lamp tube in the ultraviolet reactor.

[0021] In Steps Two, Four, and Five, record at least three sets of readings of the ultraviolet light intensity meter and calculate the average value of the readings;

[0022] In Step Seven, pass the water to be tested through the ultraviolet reactor, record a set of readings of the ultraviolet light intensity meter every 5 - 10 seconds, record at least three sets of readings of the ultraviolet light intensity meter, and calculate the average value of the readings.

[0023] Preferably, in the water distribution formula, the addition ratios of sodium lignosulfonate, corn starch, and kaolin are X:Y:Z, and the water quality adjustment target value is set to increase by 3% margin.

[0024] Preferably, the relationship between the value of the correction coefficient F and UVI / UVI 0 is: the larger the value of UVI / UVI 0 , the smaller the value of F.

[0025] The present invention also provides a method for adjusting the power and flow rate of a ship's ballast water treatment device. The adjustment method includes the following steps:

[0026] Step One: Install an ultraviolet light intensity meter so that the signal receiving window of the ultraviolet light intensity meter faces the ultraviolet lamp tube in the ultraviolet reactor, and adjust the distance d between the signal receiving window of the ultraviolet light intensity meter and the outer purple jacket tube outside the relatively arranged ultraviolet lamp tube to be 2 cm;

[0027] Step Two: Prepare water according to UVT = 95%, 90%, 80%, 75%, 70%, 60%, 50%, 40% respectively, pass it through the ultraviolet reactor, adjust the system power, run at different power set points, record the readings of the ultraviolet light intensity meter, calculate the average value of the readings, input it into the system control unit according to the set point, and the control unit automatically generates a calibration curve according to the set program;

[0028] Step Three: Pass the treated water through the ultraviolet reactor and run the system. The reading of the ultraviolet light intensity meter is the ultraviolet light intensity detected in real time, denoted as UVI d , UVI d is automatically fed back to the system control unit in real time, and the system control unit calculates the UVT of the treated water according to the calibration curve according to the following formula;

[0029]

[0030] Wherein, UVT d is the ultraviolet transmittance, and F is the correction coefficient;

[0031] Step Four: The system control unit coordinates and controls the ultraviolet lamp power and the proportional regulating valve according to the calculated UVT, in accordance with the corresponding relationship of UVT-power-flow and the set point, to adjust the power and the flow rate.

[0032] Preferably, in Step Two, the addition ratios of sodium lignosulfonate, corn starch, and kaolin in the water distribution formula are X:Y:Z, and the set value of the water quality regulation target is increased by 3% margin; at least three groups of readings of the ultraviolet light intensity meter are recorded every 5 - 10 seconds, and then the average value of the readings is obtained.

[0033] Preferably, in Step Three, the value of the correction coefficient F in the calculation formula of the ultraviolet transmittance is related to the ratio of UVI / UVI 0 ratio. The larger the value of UVI / UVI 0 is, the smaller the value of F is.

[0034] Preferably, in Step Four, the larger the value of UVT is, the smaller the value of the power P is, and the larger the value of the flow rate Q is.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention provides a detection and calculation method for the multi-band ultraviolet light transmittance of complex water quality. The error between the UVT value calculated by the detection method of the present invention and the UVT value measured in the laboratory is within 3%. The calculation result has high accuracy and small error; compared with the laboratory detection method, the present invention is easier to implement in actual engineering applications, has simple and convenient operation, small detection and calculation error, and high detection accuracy; the calculation result fully meets the actual engineering application, can truly reflect the actual absorption amount of complex water quality on multi-band ultraviolet light in actual engineering applications, and realizes real-time in-situ online detection and calculation of the ultraviolet transmittance for ultraviolet reactors using multi-band ultraviolet light, with strong practicability.

[0037] While the calculation formula of the ultraviolet transmittance of the present invention is derived based on the theoretical formula of Lambert-Beer's law, it combines a large number of test results and data induction and summary. The correction coefficient F is creatively introduced according to the actual application conditions. Compared with the calculation formula applied in the prior art, the detected and calculated data deviate greatly from the actual situation and have large errors in actual applications. The calculation result of the present invention is more in line with the actual situation, has smaller errors, and higher accuracy.

[0038] Moreover, the present invention adjusts the flow rate and power of the ballast water treatment device in real time according to the real-time detection and calculation of the ultraviolet transmittance. The adjustment method selects UVT, a direct and effective control parameter, to perform hierarchical adjustment on the ultraviolet power and flow rate. At the same time, the UVT calculation formula is adopted to ensure the accuracy of UVT detection and calculation, with high precision and small error. The control logic is simple and effective, and the actual operation is easy to implement. Moreover, the present invention optimally adjusts the power and flow rate of the treatment device according to the water quality condition, making the system operate in the best operating area, reducing energy consumption while increasing the service life of the ultraviolet lamp tubes, fully meeting the actual engineering applications. The present invention has strong practicability, high economy, energy conservation and emission reduction, and saves ship energy consumption while ensuring the ultraviolet sterilization effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0040] Figure 1 It is a schematic structural diagram of the ultraviolet treatment device for ship ballast water of the present invention;

[0041] Figure 2 It is a schematic structural diagram of the ultraviolet reactor of the present invention;

[0042] Figure 3 For the present invention Figure 2 It is a partial enlarged structural diagram at position A in the present invention;

[0043] Figure 4 It is a schematic diagram for comparing the distribution curves of UVT measured by using an ultraviolet spectrophotometer in the laboratory, UVT measured and calculated by using the present invention, and UVT measured and calculated by the prior art.

[0044] Symbols and marks in the drawings:

[0045] 1. Ultraviolet reactor; 2. Flowmeter; 3. Proportional regulating valve; 4. Ultraviolet power supply cabinet; 5. Ultraviolet control cabinet; 6. System control cabinet; 7. Ultraviolet lamp tube; 8. Ultraviolet light intensity meter; 9. Purple outer sleeve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the following further details the present application in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0047] Embodiment

[0048] Please refer to Figure 1 , the present invention provides a ship ballast water treatment device, including an ultraviolet reactor 1 and a control system. The control system is provided with an ultraviolet control unit, a system control unit, and a power supply unit. An ultraviolet lamp tube 7 is arranged inside the ultraviolet reactor, an ultraviolet light intensity meter 8 is connected to the ultraviolet reactor 1, the ultraviolet reactor 1 is connected to the control system, and a flow rate regulating and monitoring device is connected to the inlet and outlet of the ultraviolet reactor 1.

[0049] Specifically, a flow meter 2 is connected to the inlet pipeline of the ultraviolet reactor 1, a proportional regulating valve 3 is connected to the outlet pipeline of the ultraviolet reactor 1, the ultraviolet reactor 1 is externally connected to an ultraviolet power supply cabinet 4 and an ultraviolet control cabinet 5, and the flow meter 2, the proportional regulating valve 3, the ultraviolet reactor 1, the ultraviolet power supply cabinet 4, and the ultraviolet control cabinet 5 are all electrically connected to the system control cabinet 6.

[0050] Furthermore, the ultraviolet light intensity meter 8 is connected to the system control cabinet 6. A control unit is arranged inside the system control cabinet 6. The control unit calculates the ultraviolet transmittance (UVT) according to the ultraviolet light intensity (UVI) detected by the ultraviolet light intensity meter 8 in real time, and issues control commands to the ultraviolet control cabinet 5, the ultraviolet power supply cabinet 4, and the proportional regulating valve 3, etc., to make them operate coordinately, and the flow rate and power can be adjusted.

[0051] Furthermore, as shown in Figure 2 、 Figure 3 , a plurality of ultraviolet lamp tubes 7 are arranged inside the ultraviolet reactor 1. A purple outer sleeve 9 is arranged on the outer periphery of the ultraviolet lamp tube 7. The ultraviolet light intensity meter 8 is connected to the outer shell of the ultraviolet reactor 1. The distance d between the signal receiving window on the inner peripheral side of the ultraviolet light intensity meter 8 and the outer surface of the purple outer sleeve 9 opposite to it is 2 cm.

[0052] The present invention also provides a method for detecting the ultraviolet transmittance of ship ballast water, which relates to the detection and calculation of the multi-band ultraviolet transmittance of complex water quality.

[0053] Specifically, from the definition of transmittance, it can be known that the absorption characteristic of water quality to ultraviolet light, that is, the ultraviolet transmittance (UVT d ) can be expressed by the following formula:

[0054] (1)

[0055] In the formula, UVI 0 represents the incident ultraviolet light intensity, and the unit is mw / cm 2 ;

[0056] UVI d represents the remaining ultraviolet light intensity after a part of the ultraviolet light passes through a water layer with a thickness of d and is absorbed, and the unit is mw / cm 2 .

[0057] According to Lambert-Beer's law, the transmittance T :

[0058] T = φ t / φ i = e -τ (2)

[0059] In the formula, φ t represents the luminous flux after light passes through a certain medium, that is, the ultraviolet light intensity I d ;

[0060] φ i represents the luminous flux before light passes through a certain medium, that is, the ultraviolet light intensity I 0 ;

[0061] τ represents the optical depth.

[0062] If there are N kinds of ultraviolet light absorbing substances in the medium, then:

[0063] (3)

[0064] In the formula, σ i represents the absorption coefficient of a certain absorbing substance for ultraviolet light;

[0065] n i(z) represents the number concentration of a certain absorbing substance at the z depth;

[0066] d represents the total optical path of ultraviolet light penetrating the medium;

[0067] τ i represents the optical depth of a certain absorbing substance.

[0068] It can be seen from formula (3) that for a medium containing uniformly distributed absorbing substances, the number concentration at the z depth is the same, that is:

[0069] (4)

[0070] In the formula, σ i represents the absorption coefficient of a certain absorbing substance for ultraviolet light;

[0071] n i represents the number concentration of a certain absorbing substance;

[0072] d represents the total optical path of ultraviolet light penetrating the medium.

[0073] Combined with formula (2), then:

[0074] (5)

[0075] In the formula, The total absorption coefficient a can be used to represent the absorption characteristics of all absorbing substances in the medium for ultraviolet light, then:

[0076] T = e-ad (6)

[0077] Combined with formula (2), it can be known that:

[0078] T = e -ad = I d / I 0 (7)

[0079] In the formula, T is the transmittance; I d is the absorbed light intensity; I 0 is the incident light intensity.

[0080] Then the total absorption coefficient a can be deduced:

[0081] (8)

[0082] Since the internationally common laboratory detection method for UVT is the transmittance of light through a medium with a depth of 1 cm, that is, d = 1 cm, combined with formula (1), it can be known that:

[0083] UVT = e -a×1cm × 100% = e -a × 100% (9)

[0084] Combined with formula (8), it can be known that:

[0085] (10)

[0086] Combined with formula (7), it can be known that formula (1) can be expressed as:

[0087] (11)

[0088] In the formula, UVI 0 represents the incident ultraviolet light intensity, and the unit is mw / cm 2 ;

[0089] UVI d It represents the intensity of the remaining ultraviolet light after a part of the ultraviolet light is absorbed by a water layer with a thickness of d, and the unit is mw / cm 2 .

[0090] Then:

[0091] (12)

[0092] Then:

[0093] (13)

[0094] The above is the calculation method of the ultraviolet transmittance. However, due to the complex situation in actual engineering, there are certain limitations in the theoretical formula. Directly applying the theoretical formula may result in relatively large errors in the calculation results, thus unable to truly reflect the absorption of ultraviolet light. Therefore, after a large number of experimental tests and data induction and summary, a correction coefficient F is creatively introduced based on formula (13) to obtain formula (14):

[0095] (14)

[0096] The corresponding relationship between the value of the correction coefficient F and UVI / UVI 0 is: the larger the value of UVI / UVI 0 , the smaller the value of F. The specific value relationship is shown in the following table:

[0097] Table 1 Corresponding Table of the Value of the Correction Coefficient F

[0098]

[0099] Specifically, the detection method of the ultraviolet transmittance of ship ballast water includes the following steps:

[0100] Step 1: Install the ultraviolet light intensity meter 8 so that the signal receiving window of the ultraviolet light intensity meter 8 faces a certain ultraviolet lamp tube 7 in the ultraviolet reactor 1; the signal receiving window of the ultraviolet light intensity meter 8 forms a 90-degree angle with the axis of the opposite ultraviolet lamp tube 7 in the ultraviolet reactor 1;

[0101] Adjust the distance d between the signal receiving window of the ultraviolet light intensity meter 8 and the outer surface of the purple outer sleeve 9 outside the opposite ultraviolet lamp tube 7 to 2 cm;

[0102] Step 2: Pass clear water with UVT≥95% and turbidity≤3NTU through the ultraviolet reactor 1, record a set of readings of the ultraviolet light intensity meter 8 every 5 - 10 seconds, record at least three sets of readings of the ultraviolet light intensity meter 8, calculate the average value of the readings, and record this reading as 95% UVI 0 ; UVT is the transmittance of ultraviolet light through a medium with a depth of 1 cm;

[0103] Step 3: Add sodium lignosulfonate, corn starch, kaolin, etc. to clear water with UVT≥95% and turbidity≤3NTU in a certain proportion, adjust the physicochemical properties of the water quality (POC, DOC, TSS, MM, salinity), etc., and adjust the UVT to UVT = 90%;

[0104] Step 4: Pass the water with adjusted proportion (UVT = 90%) through the ultraviolet reactor 1, record a set of readings of the ultraviolet light intensity meter 8 every 5 - 10 seconds, record at least three sets of readings of the ultraviolet light intensity meter 8, calculate the average value of the readings, and record this reading as 90% UVI 0 ;

[0105] Step 5: Repeat Step 3 and Step 4, respectively prepare the water to UVT = 80%, 75%, 70%, 60%, 50%, 40%, and respectively pass the water with different UVT through the ultraviolet reactor 1, record a set of readings of the ultraviolet light intensity meter 8 every 5 - 10 seconds, record at least three sets of readings of the ultraviolet light intensity meter 8, calculate the average value of the readings, and record these readings as 80%, 75%, 70%, 60%, 50%, 40% UVI 0 ;

[0106] Step 6: Make a calibration curve based on the UVI detected by different prepared water UVT, with the abscissa being UVT and the ordinate being UVI;

[0107] Step 7: Pass the water to be tested through the ultraviolet reactor 1, record a set of readings of the ultraviolet light intensity meter 8 every 5 - 10 seconds, record at least three sets of readings of the ultraviolet light intensity meter 8, calculate the average value of the readings, and record this reading as UVI d ;

[0108] Step 8: Intersect the UVI d with the calibration curve made in Step 6, take the UVI values at 2 points near the intersection point, calculate the UVI / UVI 0 ratio, and determine the value of the correction coefficient F according to the calculated UVI / UVI 0 ratio in Table 1;

[0109] Step 9: Substitute UVI 0 , UVI d and the F value into the following formula:

[0110]

[0111] In the formula, F is the correction coefficient;

[0112] UVI 0 represents the incident ultraviolet light intensity, and the unit is mw / cm 2 ;

[0113] UVI drepresents the intensity of the remaining ultraviolet light after a part of the ultraviolet light passes through a water layer with a thickness of d, and the unit is mw / cm 2 .

[0114] In the above formula, the value of the correction coefficient F is related to the ratio of UVI / UVI 0 ratio. According to the calculated UVI / UVI 0 ratio, determine the value of the correction coefficient F in Table 1.

[0115] Thus, the corresponding UVT is calculated d .

[0116] Furthermore, in the first step of the present invention, by installing the ultraviolet light intensity meter 8 at a position where the distance d between its signal receiving window and the outer surface of the purple outer tube 9 of the ultraviolet lamp tube 7 facing it is 2 cm, the installation is convenient and fast, the measurement error is small, and the accuracy is high.

[0117] Furthermore, in the second, fourth, fifth, and seventh steps, by recording at least three groups of readings of the ultraviolet light intensity meter 8 and taking the average value of the readings as UVI 0 , the accuracy of the measurement result is increased, and the error is small.

[0118] Furthermore, in the third step, the addition ratios of sodium lignosulfonate, corn starch, and kaolin in the water preparation formula are X:Y:Z, and the water quality adjustment target value is set to increase by 3% margin, so that the prepared water is closer to the actual water quality situation.

[0119] In order to determine the compatibility between the UVT measured and calculated based on formula (14) of the present invention and the UVT measured by the internationally common method (the transmittance when using a single wavelength of 254 nm UV at an optical path of 1 cm), as well as the UVT measured and calculated based on the published calculation formula (10), 13 water samples to be tested are selected, and the UVT is measured and calculated respectively, and the measurement results are plotted into a graph. This curve graph is as Figure 4 shown. In the figure, the abscissa is the ordinal number of the test water sample, and the ordinate represents the transmittance (UVT) value of the ultraviolet light.

[0120] Figure 4 In, the curve UVT1 is the distribution curve of the UVT measured by the ultraviolet spectrophotometer. The two rhombuses distributed diagonally up and down represent the specific values of the UVT, and the standard variance R² = 0.15213;

[0121] The curve UVT2 is the distribution curve of the UVT measured and calculated based on formula (14) of the present invention. The squares represent the specific values of the UVT, and the standard variance R² = 0.15768;

[0122] The curve UVT3 is the distribution curve of UVT measured and calculated using the existing public formula (10), where the triangles represent the specific values of UVT, and the standard variance R² = 0.15953.

[0123] The test results show that the linear fit between UVT2 measured based on the calculation method of the present invention and UVT1 detected in the laboratory is good, and the higher the UVT, the better the fit. However, there is a difference of up to about 3% between the two. The main reasons for the difference are as follows: The measurement of UVT in the laboratory uses a single wavelength of 254 nm, while the present invention uses an on-line ultraviolet light intensity meter, and the wavelength range of emission and reception is between 220 - 280 nm, belonging to multiple bands. The linear deviation between UVT3 measured based on the publicly available calculation formula (10) and UVT1 detected in the laboratory is relatively large, with a difference of approximately 5%.

[0124] It has been experimentally proven that when single-band and multi-band light pass through the same medium, the degree of absorption of each wavelength is different, and thus there will be a difference in the two UVT values. In view of the fact that the international measurement standard of UVT is the percentage of UV absorption before and after passing through a 1-cm optical path of the medium at 254 nm, therefore, the calculation result of the present invention reflects the true UVT closer to the water quality.

[0125] The UVT value calculated by the detection method of the present invention has an error within 3% compared with the UVT value measured in the laboratory. The calculation result has high accuracy and small error. Compared with the laboratory detection method, the present invention is easier to implement in actual engineering applications, with simple and convenient operation, small detection and calculation errors, and high detection accuracy. The calculation result fully meets the actual engineering application, can truly reflect the actual absorption of multi-band ultraviolet light by complex water quality in actual engineering applications, and realizes real-time in-situ on-line detection and calculation of ultraviolet transmittance for ultraviolet reactors using multi-band ultraviolet light, with strong practicability.

[0126] Furthermore, the present invention also provides a method for adjusting the power and flow rate of a ship's ballast water treatment device, which is based on the above-mentioned ship's ballast water treatment device, and the adjustment method includes the following steps:

[0127] Step 1: Install the ultraviolet light intensity meter 8, make the signal receiving window of the ultraviolet light intensity meter 8 face a certain ultraviolet lamp tube 7 in the ultraviolet reactor 1, and adjust the distance d between the signal receiving window of the ultraviolet light intensity meter 8 and the purple outer sleeve 9 outside the relatively arranged ultraviolet lamp tube 7 to be 2 cm.

[0128] Step 2: Use a specific formula to prepare water with UVT = 95%, 90%, 80%, 75%, 70%, 60%, 50%, and 40% respectively, and pass it through the ultraviolet reactor 1. Adjust the system power and operate at different power set points. Record the readings of at least three groups of ultraviolet light intensity meters 8 every 5 - 10 seconds, and then calculate the average value of the readings. This reading is the reference ultraviolet light intensity at the set power point, which is input into the control unit according to the set point. The control unit automatically generates a calibration curve according to the set program.

[0129] Step 3: Pass the treated water through the ultraviolet reactor 1 and operate the system. The reading of the ultraviolet light intensity meter 8 is the ultraviolet light intensity detected in real time, denoted as UVI d , UVI d is automatically fed back to the control unit in real time. The control unit calculates the UVT of the treated water according to the calibration curve using the following formula:

[0130]

[0131] In the formula, UVT d is the ultraviolet transmittance, and F is the correction coefficient;

[0132] UVI 0 represents the incident ultraviolet light intensity, with the unit of mw / cm 2 ;

[0133] UVI d represents the remaining ultraviolet light intensity after a part of the ultraviolet light is absorbed by the water layer with a thickness of d, with the unit of mw / cm 2 .

[0134] The value of the correction coefficient F is related to the ratio of UVI / UVI 0 . Determine the value of the correction coefficient F according to the calculated ratio of UVI / UVI 0 in Table 1.

[0135] Step 4: The control unit coordinates the control of the power of the ultraviolet lamp 7 and the proportional regulating valve according to the calculated UVT and the corresponding relationship and set point shown in the UVT - power - flow classification adjustment table, and adjusts the power and flow rate.

[0136] Furthermore, in Step 2, the addition ratios of sodium lignosulfonate, corn starch, and kaolin in the water preparation formula are X:Y:Z, and the set value of the water quality adjustment target is increased by 3% margin, making the prepared water closer to the actual water quality. Record the readings of at least three groups of ultraviolet light intensity meters every 5 - 10 seconds, and then calculate the average value of the readings.

[0137] The UVT - power - flow classification adjustment table is specifically shown in Table 2.

[0138] Table 2 UVT - power - flow classification adjustment table

[0139]

[0140] The data in Table 2 is the optimal combination after being verified by CFD simulation calculation and actual operation test. While meeting the ultraviolet sterilization dose, it realizes the precise adjustment of power and flow rate. In Table 2, Q1 < Q2 < Q3 < Q4 < Q5, and P1 > P2 > P3 > P4. Therefore, the larger the value of UVT, the smaller the value of power P and the larger the value of flow rate Q.

[0141] Furthermore, the ultraviolet transmittance UVT is a parameter that can directly reflect the ultraviolet light intensity and water quality conditions. For the same ultraviolet lamp, when other conditions are the same, if the water quality is clean, UVT is large, and the number of microorganisms and bacteria to be killed is small, the power can be reduced and the flow rate can be increased; while if the water quality is dirty, UVT is small, and the number of microorganisms and bacteria to be killed is large, the power can be increased and the flow rate can be reduced.

[0142] The present invention adjusts the flow rate and power of the ballast water treatment device in real time according to the real-time detection and calculation of the ultraviolet transmittance. The adjustment method selects UVT, a direct and effective control parameter, to perform hierarchical adjustment on the ultraviolet power and flow rate. At the same time, the UVT calculation formula (14) is adopted to ensure the accuracy of UVT detection and calculation, with high precision, small error, simple and effective control logic, and easy to implement in actual operation.

[0143] The present invention provides a detection and calculation method for the ultraviolet transmittance of multi-band ultraviolet light applicable to complex water quality. The error between the UVT value calculated by the detection method of the present invention and the UVT value measured in the laboratory is within 3%. The calculation result has high precision and small error; compared with the laboratory detection method, the present invention is easier to implement in actual engineering applications, with simple and convenient operation, small detection and calculation error, and high detection precision; the calculation result fully meets the actual engineering application, can truly reflect the actual absorption amount of multi-band ultraviolet light by complex water quality in actual engineering applications, and realizes the real-time in-situ online detection and calculation of the ultraviolet transmittance of the ultraviolet reactor using multi-band ultraviolet light, with strong practicability.

[0144] The ultraviolet transmittance calculation formula (14) provided by the present invention is derived based on the theoretical formula Lambert-Beer's law, and at the same time, combines a large number of test results and data summaries. According to the actual application conditions, a correction coefficient F is creatively introduced. Compared with the calculation formula (10) applied in the prior art, which has a large deviation between the detected and calculated data and the actual situation and a large error in actual application, the calculation result of the present invention is more in line with the actual situation, with smaller error and higher precision.

[0145] Moreover, the present invention performs real-time adjustment on the flow rate and power of the ballast water treatment device based on the real-time detection and calculation of the ultraviolet transmittance. The adjustment method selects UVT, a direct and effective control parameter, to perform hierarchical adjustment on the ultraviolet power and flow rate. At the same time, the UVT calculation formula (14) is adopted to ensure the accuracy of the UVT detection and calculation, with high precision, small error, simple and effective control logic, and easy implementation in actual operation. Moreover, according to the water quality condition, the present invention optimally adjusts the power and flow rate of the treatment device, enables the system to be in the best operating area, increases the service life of the ultraviolet lamp while reducing energy consumption, fully meets the actual engineering application, has strong practicability, high economy, energy conservation and emission reduction, and saves the ship's energy consumption while ensuring the ultraviolet sterilization effect.

[0146] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present application.

[0147] In addition, in the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0148] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0149] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. Detection method for ultraviolet transmittance of ship ballast water Characterized in that it is carried out by using a ship ballast water treatment device, the ship ballast water treatment device includes an ultraviolet reactor and a control system, the control system is provided with an ultraviolet control unit, a system control unit, and a power supply unit, an ultraviolet lamp tube is arranged inside the ultraviolet reactor, an ultraviolet light intensity meter is connected to the ultraviolet reactor, the ultraviolet reactor is connected to the control system, and a flow rate adjustment and monitoring device is connected to the inlet and outlet of the ultraviolet reactor; the detection method includes the following steps: Step 1: Install the ultraviolet light intensity meter so that the signal receiving window of the ultraviolet light intensity meter faces the ultraviolet lamp tube inside the ultraviolet reactor, and at the same time adjust the distance d between the signal receiving window of the ultraviolet light intensity meter and the outer purple jacket tube outside the relatively arranged ultraviolet lamp tube to 2 cm; Step 2: Pass clear water with UVT ≥ 95% and turbidity ≤ 3 NTU through the ultraviolet reactor, record the reading of the ultraviolet light intensity meter, and denote this reading as 95% UVI 0 ; Step 3: Add sodium lignosulfonate, corn starch, and kaolin to clear water with UVT≥95% and turbidity≤3 NTU in proportion, and adjust the UVT to UVT = 90%; Step 4: Pass the water with adjusted ratio through the UV reactor, record the reading of the UV light intensity meter, and denote this reading as 90% UVI 0 ; Step 5: Repeat Step 3 and Step 4, respectively adjust the water to UVT = 80%, 75%, 70%, 60%, 50%, 40%, pass the water with different UVT values through the ultraviolet reactor respectively, record the readings of the ultraviolet light intensity meter, and denote these readings as 80%, 75%, 70%, 60%, 50%, 40% UVI 0 ; Step 6: Make a calibration curve according to the UVI detected by the UVT of different prepared waters, with the abscissa being UVT and the ordinate being UVI; Step 7: Pass the water to be tested through the ultraviolet reactor, record the reading of the ultraviolet light intensity meter, and denote this reading as UVI d ; Step Eight: Perform UVI on the calibration curve obtained in Step Six d to intersect with the calibration curve, take two UVI values near the intersection point, and calculate the UVI / UVI 0 ratio. Determine the value of the correction factor F based on the calculated UVI / UVI 0 ratio Step Nine: Substitute UVI 0 , UVI d and the F value into the following formula: Calculate the corresponding UVT d .

2. The detection method for ultraviolet transmittance of ship ballast water according to claim 1 Characterized in that a plurality of ultraviolet lamp tubes are arranged inside the ultraviolet reactor, a purple jacket tube is arranged outside the ultraviolet lamp tube, and the distance between the inner end of the ultraviolet light intensity meter and the outer surface of the relatively arranged purple jacket tube is d; a flow meter and a proportional regulating valve are respectively connected to the inlet pipeline and the outlet pipeline of the ultraviolet reactor, and the flow meter and the proportional regulating valve are both connected to the control system.

3. The detection method for ultraviolet transmittance of ship ballast water according to claim 1 Characterized in that in step 1, the signal receiving window of the ultraviolet light intensity meter forms a 90-degree angle with the axis of the relatively arranged ultraviolet lamp tube inside the ultraviolet reactor.

4. The detection method for ultraviolet transmittance of ship ballast water according to claim 1 Characterized in that in steps 2, 4, and 5, record at least three readings of the ultraviolet light intensity meter and calculate the average value of the readings; in step 7, pass the water to be tested through the ultraviolet reactor, record a set of readings of the ultraviolet light intensity meter every 5 - 10 seconds, record at least three sets of readings of the ultraviolet light intensity meter, and calculate the average value of the readings.

5. The detection method for ultraviolet transmittance of ship ballast water according to claim 1 Characterized in that the addition ratio of sodium lignosulfonate, corn starch, and kaolin in the prepared water formula is X:Y:Z, and the water quality adjustment target value is set to increase by 3% margin.

6. The detection method for ultraviolet transmittance of ship ballast water according to claim 1 Characterized in that The value of the correction coefficient F is related to UVI / UVI 0 as follows: the larger the value of UVI / UVI 0 , the smaller the value of F.

7. Power and flow rate adjustment method for ship ballast water treatment device Characterized in that it uses the detection method for ultraviolet transmittance of ship ballast water according to claim 1, and the adjustment method includes the following steps: Step 1: Install the ultraviolet light intensity meter so that the signal receiving window of the ultraviolet light intensity meter faces the ultraviolet lamp tube inside the ultraviolet reactor, and adjust the distance d between the signal receiving window of the ultraviolet light intensity meter and the outer purple jacket tube outside the relatively arranged ultraviolet lamp tube to 2 cm; Step 2: Prepare water with UVT values of 95%, 90%, 80%, 75%, 70%, 60%, 50%, and 40% respectively. Pass the water through the UV reactor, adjust the system power, operate at different power set points, record the readings of the UV light intensity meter, calculate the average value of the readings, input the average value into the system control unit according to the set point, and the control unit automatically generates a calibration curve according to the set program; Step 3: Pass the treated water through the UV reactor and run the system. The reading of the UV intensity meter is the UV light intensity detected in real time, denoted as UVI d , UVI d is automatically fed back to the system control unit in real time. The system control unit calculates the UVT of the treated water according to the calibration curve using the following formula; wherein, UVT d is the ultraviolet transmittance, and F is the correction coefficient; Step 4: Based on the calculated UVT, the system control unit coordinates and controls the power of the UV lamp and the proportional regulating valve according to the corresponding relationship of UVT - power - flow and the set point, and adjusts the power and flow.

8. The method for adjusting the power and flow of the ship's ballast water treatment device according to claim 7, wherein, in the said Step 2, the addition ratios of sodium lignosulfonate, corn starch, and kaolin in the water preparation formula are X:Y:Z, and a 3% margin is set for the water quality adjustment target value; record at least three groups of readings of the UV light intensity meter every 5 - 10 seconds, and then calculate the average value of the readings.

9. The method for adjusting the power and flow of the ship's ballast water treatment device according to claim 7, wherein, In the third step, the value of the correction coefficient F in the calculation formula of the ultraviolet transmittance is related to the UVI / UVI 0 ratio. The larger the value of UVI / UVI 0 , the smaller the value of F; in the said Step 4, the larger the value of UVT, the smaller the value of power P and the larger the value of flow Q.

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